Again, we have Professor Sun Jia-sui. She's our friend, as you probably heard the introduction a few days ago, given by David. He was, I don't know why he made faces. Sorry. I think you probably know Professor Sun's work because she's really quite active in the media studies and also in the past few years, she's really focusing on Indigenous medias. So this is one particular lecture she actually presented to contribute to our publication project. This is something that Taylor made for the Shen Yi project. So this is quite a different topic from her usual thing, but you can see, again, because she's such an expert in the media studies, she presented her presentation with loads of multimedia presentation here, so you will be totally entertained as well as informed. So let us put our hands together and welcome her coming back. Okay, thank you. I'm going to present for this session is Indigenous media uses the means of cultural change in the period of transformation of cultures in Taiwan. So I'm going to look at the media in the social and cultural context and I will have an overview of the Indigenous media in Taiwan first and then focus on two different perspectives. One is about cultural sustainability and the youth's audience, and the second one is about cultural creative industry. So you are going to do a two different side of the media. Indigenous media can convey significant cultural and social meanings in Taiwan, but all of this talk is to show different cultural forms of Indigenous media in Taiwan and investigate roles which Indigenous media check in the changing culture and social context in Taiwan. Indigenous media also build a connection between the Indigenous culture and the white world. In the cultural policy aspect, Indigenous media not only keep tradition, also enhance opportunity for creating possibility for further facilitate different cultural forms such as Indigenous music and Indigenous craft. So later I will talk more about music because the radio part actually provides a good channel for a lot of Indigenous music to reach wider audience. When Indigenous society encounter changes, Indigenous media become an important cultural and social means to engage with Indigenous social movement, cultural changes and maintenance of Indigenous language. So this talk also explores representation of different Indigenous media forms and reveal cultural translation among different Indigenous culture and language in Taiwan. By taking over of the development of Indigenous media in Taiwan, this talk endeavours to analyze and explain ways in which Indigenous media strengthen the identity of Indigenous people, show the cultural heritage of tribes, help to maintain Indigenous language and also become public appeal for debating about Indigenous issues. So here I'm going to give the overview. When people talking about Indigenous media, first of all we are thinking about the Taiwan Indigenous television news. So I'm going to, so for the pre-media one, Indigenous perspectives that I monthly may be viewed. I think the first one is more influential because there are more people looking at the television one. And the radio, the special one of radio is because some program actually is all designed by Indigenous language. So it's not the program is not spoken by Chinese but spoken in their own language. Also a lot of music one. Right now I think I have a lot of young people using their own language but produce some. And this is a very good channel for them to let the people understand the music and also get no more about its content or what kind of social issue involved with the music. And new media and social media, they are very diverse. Media force actually connected through internet. I think more than one people's paper actually mentioned about this, like they are learning language but they have different community through internet and connect with each other, like Sai Xia. Sai Xia actually they design APP and through internet. They are many words sometimes they don't know how to say in a correct way. So in a foreign on the internet they can discuss with it or sometimes they find a problem and then they seek with the elder people to find what is the right way to express the certain issues. And they also build certain kind of identity through social media. So internet play an important role in the modern tribe because it also connect with young people and elder people through new media forward. To talking about indigenous television news and indigenous knowledge and they are cultures sustainability and youth audience. So they are four main points. First one to investigate the ways in which indigenous television news convey and transform indigenous knowledge in Taiwan. The second one is presenter acting as cultural agent translate and adopt news from different ethnic and cultural backgrounds. And the third one indigenous presenters not only translate news from different language but also translate across different cultural space. And the final one is about youth audience. Very focused indigenous television news, media culture workers and young audience. The methodology are used counter analysis of news program in indigenous news. Also interviews of presenters and also do audience research for undergraduate student. Indigenous television news has become part of education system to sustain indigenous cultural language and indigenous knowledge to benefit the young generation. With social change many young indigenous people actually grow up in cities and do not have opportunity to learn their own native language. Therefore it become a difficult language choice for the producer of the news when producing indigenous news. I think it's not only happening in indigenous news sometimes also happening in Hakka. Sometimes a producer feel they actually try hard to do good news but not so many audience really see them. And for natural interview actually I asking many presenters and anchors and check whether their children can understand their own language. But even their children sometimes they speak yeah because they are in a good position so they stay in the city so that's why their children also couldn't they are they are growing in the city it's more like hand children not like indigenous people. But if indigenous news and program only making news for elder people when they are getting older who are who will become the audience to looking at all of those news. So right now it's kind of important for the people to find a way to train the young people also can get to know their own language. So later they actually have some children program start to use indigenous language teaching system to let them can get access with their own culture. Indigenous knowledge cultural sustainability and use of this they are different indigenous language in Taiwan and to cope with this range of indigenous TV news. For casters have anchors with different indigenous language backgrounds to produce news from a number of ethnic groups. However there are debates when selecting which subtitle to use. Most people in Taiwan can understand television news by the subtitle even though they can understand indigenous language. Other people insist that indigenous television news should not only report indigenous language the subtitle should use roman spelling to make it fit well to the spoken form and sound like the indigenous language. The indigenous television news anchor originally work as indigenous language teachers or priests. There are very few people who retain the ability to speak an indigenous language and can report for the public. Most of them are over 50 years of age. That's I think somewhere else in the last talk why they are not the young people that's why because they are language teacher or they are priests so they know how to use but the younger people they haven't have this ability to report it and these are the reception from the young audience. When I saw the old anchor's report of news with my own language I could sympathize with him. The anchor was from my village and more than 80 years old. It does not enjoy good health but continue reporting a desire to sustain our language. It makes me feel I should learn my language well so the young generation can turn over to sustain the cultural and language. This is one response. Here's another one. I feel that anchors are too old and I don't understand the language so I tend to switch to other channels with the young anchors who use language which I can understand so you see different perspective. Indigenous news often report news about problem of indigenous issues which makes me feel hopeless. Most of the people who appear in the news are farmers workers or working classes people. They are not people who work in office. It makes me feel that most of the indigenous people cannot find good job in their village so need to go far to find better jobs. I think the indigenous television should report more positive news instead of just reporting the news which focuses on problems of indigenous issues. The news is a bit too heavy showing news with all kinds of problems and I think this one also echoed the previous talk talking about many people actually couldn't find a proper job but if you keep showing the problems for all these he looking at the news it didn't really like encourage them to do something good so I think later this opinion also they also care about this one and put more positive news with that. Young audience perspective also points out that indigenous news should report about more modern issues. It is essential for a reporter to try and report traditional issues in a modern form and link with modern issues. So I think if everything is traditional sometimes it's hard to attract young people because they feel that's something too hard to connect with their own life and also the music is not only the traditional one they also need to combine with some modern music or modern design so more and more people would like to see all of the news and learn from it. Media and space. Craig talking about literature become a means to create culture space for consumers. So radio drama and everyday life full belief and common value and Biden image community. Radio drama is a media space interacted with society in the UK and also I think the media in Taiwan can also do the same thing. The anchor of Beno when indigenous ethnic group indigenous language news this one give an example to show how indigenous television news convey and sustain indigenous cultural knowledge. By reporting news about Forest Museum in Taidong he utilised ways in which indigenous elder introduced the wisdom of mountains to emphasise the value of Beno places upon presenting nature to young people. It's more like an environmental education in an indigenous way and right now actually it's quite popular a lot of tourism designed this way. They guide I think many people from Hong Kong and different parts of the world actually they find the news first and then just go to the village and they are elder people teaching them how to cook in the original way and introduce the environmental issues with them so it's more and more connection through the news to combine with different connection but no more living in mountain regions develop indigenous knowledge to interact with nature the elder introduced the Benoan indigenous knowledge through the news report they also teach them how to use the knife because the knife can use different way to not only cut the tree also find the rope so there are a lot of indigenous knowledge actually contain in the news. Train young people how to stay in accommodation without the trees. Yeah so many people actually they like to see all kind of loose news and learn something new and later they can also go to the tribe to experience about it work in different ways when in mountains region to ensure they will not destroy the environment so there are a lot of education also involved with it. The Benoan indigenous news also record upon the choir at the beginning of the festival. The singer usually sing early in the morning between 3 and 5 a.m because it is very quiet we see enable the choir to sing in a peaceful space in a humble manner so the singing can be here and convey to God then God will give permission for the star of the festival. It addresses the relationship of Benoan tribe heaven and land it shows the humble way of Benoan people to God and nature so it's the news it's not only a news it also have a lot of value original from the tribe through news and to let people understand indigenous knowledge. Many presenters in indigenous television news encounter problems when reporting news and events about which local village people may not be able to understand or even issues which did not exist in a local cultural concept. They not only report news but also become the cultural translator of different cultural boundaries through the reporting process. A example from Sakinu, one time Taiwan anchorman in indigenous Taiwan ethnic TV news, the waves from nuclear power generating plants become an important issue in Taiwan. Some people are closely linked with the issue because the waves from nuclear power generation may be located in their village so that's why I just see the news and that's why they go for demonstration so media actually tap part in the social participation in Taiwan and respond indigenous people's opinion. Difficult for the anchor to report this kind of news in indigenous language because there's no words in the indigenous language to describe the chemistry of the waves. Some indigenous people may believe the waves to be an evil spirit that's how they transform use different concept to describe it to use word which indigenous people can understand when we pull the news so everybody can get a sense about what it is. The anchor must bridge indigenous life to a modern world and at the same time transform indigenous knowledge to embrace modern issues in reporting news. The anchor must be aware of modern issues but also be familiar with indigenous knowledge. Do social issues need to be translated and explained to indigenous people? Cultural sustainability must also be conveyed to the young audience to help them protect their homeland and the indigenous way they interact with nature. So conclusion for this part put different subtitles with the same news counter and show in different time for audience to choose. Introduce new vocabulary in the news with modern issues. Presenters for indigenous themes to be successful in its go to sustain indigenous culture. It is essential for a reporter to try and report indigenous issues in a modern form and link with modern issues. Minority media can be a tool to fix for social justice and that's the one like the hunting one because it really causes a big huge attention and actually a lot of law people actually try to involve with indigenous lawyer to make some change for to make the justice for indigenous people. Indigenous news should have more positive reports to inspire the young generation and enhance their ethnic competence. Presenters become the cultural translator of different cultural boundaries through a reporting process and sustain culture. And I'm going to skip this one. And the second part is impact of media on indigenous Taiwanese literature. Example from a publishing and creative industry. And I think this one is also about a story that is in indigenous way. So there are four points. First one the impact of new technology is effect upon the development of the publishing industry and it's linked to the indigenous and Taiwanese literature. Second one the connection between indigenous and Taiwanese literature publishing and cultural creative industry. And the third one media space and cultural landscape. How the contents of a book can be transformed into different cultural forms, cultural products, different media forms and linked to the change of cultural landscape. And the final one cultural development through indigenous and Taiwanese literature. And what I'm trying to say is media is not only media. Media can connect with different ones. It may probably just start from a story but later it can become different on media form also interact with different societies and networks and from not only bring the impact we see in the nation also can go to wider audience. This talk regards publishing as one kind of media in its pro-indigenous and Taiwanese literature in the framework of media culture society with the development of new technology and the cultural policy of promoting cultural creative industry. Indigenous and Taiwanese literature has become transformed to different media forms to interact with Taiwanese culture and their stuff. Taiwanese literature has been regarded as a concept of text in this talk and its role of mainstream perspective. People assess Taiwanese literature through different media forms. The media impact of Taiwanese literature when transformed to different media forms connect with different social issues such as indigenous movement, cultural imagination, transformed stories to interact with history, local cultural landscape and media space to connect with local people and form new network. So this talk will deal with some of opportunities and challenges that the Taiwanese publishing industry has come from in the transition from a domain, a domain printed media to an increasing digital media form. I think I just show you some. Now this is a story of a princess following. So you can see a little. It's more like a legend. Legend of indigenous stories and from the legend they are also different kind of music and this is one way of like transformation from a story to the media form and this is the second one. This is a Daya story. They are tracing the song. So you can see this one and this is Senekou Balai. So you can see. It is not only movie. They are also different kind of like the painting in one with it. And this is a TV drama talking about Ushou event. That's a very important history event and it becomes a television news. This person, they are indigenous people. So it's not only elder people also young people participating in it. So from the production process, many people just part in with the production and also they are a lot of wider influence to reach a different different kind of ethnic ethnic group. So this is the book Virgin and the painting actually with many some detail to explain like that. So they are also contain some indigenous knowledge with that. And this is Mona Luka, the story with the important people in indigenous history. This is a different version of Ushou event. And this is a very famous painter to paint all of Lo's story and this is Helty. This is a musical address about a doctor in Alishan Zhouzu and the story also become musical and show in different places. I'm going to show you some. This is Taiwanese literature but I think indigenous literature also can do something similar. This is Laihe and Laihe's story also linked with different cultural landscape like the museum and this is music and this is like the work. Different people can walk through it. So literature and cultural landscape. The landscape embody a cultural imagination of literature and literature reshaped cultural landscape. We get representation of cultural heritage, renovation. It's only that that's not only related with Taiwanese literature also can involve with a lot of indigenous language. So it's like literary park guided tour, literature camp, building connection with everyday life and people. So you can see media just a starting point to connect with different kinds of social network. And Zhong Yi He, this is another example from Haka. So from the story and then you can go to the real landscape and then they are museum and different expression with that. Okay, so this is Laihe and cultural landscape. It's a transfer local community and connect local network, cultural space of cultural communication and connect the story also local landscape. New cultural map and cultural imagination actually really mapping the landscape in different ways through different story. From Taiwanese literature publishing to media space and cultural landscape, literary space and a connection with cultural society and new mediation for Aboriginal people. So that's another way I'm trying to address story can be a starting point and then it can become different kind of media form to link with a different kind of social network and it is not only to strengthen the cultural identity, it also can bring different kind of network so different kind of media form. The transformation of the stories connect the identity, cultural preservation, thank cultural network. For example, like the music one, Sumin is a good example because a lot of people will be here and then all of those fan people just start to love Indigenous music and I think his music also cooperate not only with different media form also with the group from different countries. For example, I attend one concert in National Music Hall, actually he's he use Indigenous music to come with Okinawa music. So there are a lot of mixing music. It's not only the traditional one, it also mixing with many new way of possibility. And the way of the danger, the literature transform media has been used for different purpose but away from their original meaning and intent. Let's find yesterday when Dale talking about some Indigenous film, I think the story is it's not only story itself, it shouldn't be like another kind of Disney or Hollywood just with the skin of Indigenous factors. I think it's important to know of Indigenous knowledge and value and to create something new but with Indigenous spirit in it and that's an important factor for the media when they are trying to show in the Indigenous news or when they do some different creation. I think it's not it's not Indigenous everything if they contain something with Indigenous factor, not necessary means that's Indigenous. I think it's important to have something more sophisticated and contain the value with all of those media and then Indigenous media can become an important platform to connect with different things no matter culturally or socially and then can make some change in Taiwan society. Also it can become a platform to link globally in different ways. Okay that's my talk. Okay I have two questions but it's really quite interesting to see how you divide the talk into two parts on the one hand you are tackling the really about Indigenous news and in basically in the broadcast in Indigenous TV station right the next one is more general mapping about the cultural landscape so my question for you is first is there's a very clear general sorry generational specific sort of content and media for example radio seem to target on more elderly because they have to speak in Indigenous languages but blog online thing is much more younger people's media how are you going to what are their strategies to attract Indigenous people across the board are there any kind of strategies they you know they use to really expand and outreach to different you know conventional groups another thing is to do with you you said young people seem to be complaining about it's always talking about problems so if there's always then you said oh maybe we should be more encouraging talking about nice things but you are from journalism background as well as me so you are not encouraged as well as well you're not encouraged to just gloss over things so how are you going to provide a certain kind of strategies to on the one hand really truthful to to what's going on but on the other hand you know how are you going to encourage people to aim for better things for the first question I think the audience are very diverse so let's for example they design different kind of news like for the elder one they have the Indigenous television news that means they use their own language but for the young generation they have daily news and that's why they use Chinese title with that so they can reach different audience and on the internet actually the age group different age group they all use internet to form different kind of community and discuss something different for example like social movement why quite a lot of young people they have like the internet group and participants in it through the internet but also they are elder people they probably participate for social movement even 40 years ago so two groups probably have different strategies to target about the nuclear power waste but they all use internet to connect with different way it's not only one answer and or one way to participate with the social movement so they are different group of people with different age but they all use new media to discussion or to provide different strategy and also language one because people are interested with different things so they all have different kind of group for example like language one or like they use internet to sell the product or aircraft for the for the tribe and they are also young people right now they are also like new farmer they are actually with new technology skill and but they use different way to grow plants and to marketing them or invite people to go to the go to the tribe or they design different kind of a tourism but it's a more they put a lot of indigenous concept or knowledge with that but they also need the help of elder people because they are kind of the uh can contain all flows of wisdom so internet become one way to bridge different age group and also invite people to join them in a new way so that's our first one and for the second one I think later they still address the problem but they also provide the possibility to solve it yet so it's not only address the problem they will also provide different ways or become a forward to let people pay attention about the issue but also try to solve the problem so in that way it's not the problem is just the beginning and then later they will follow up with how to solve this problem for example like if they are people they did not get a good job in the tribe in what ways they can they can uh they are a new connection with that or they are a lot of uh social harassment in the tribe sometimes and in what ways you can improve such kind of situation so it's not only the problem itself later they have a discussion with that so it's not only a negative part um sure originally I would like to have Xiao Wen's question but since this being already being handed to you sorry about that I'm sorry yeah um uh I'm very interesting in the last part uh like last year I went to the like a literature festival in in Zhanghua city like I I think like the same day they did they achieve is luckily is uh Leihem memory hole is in the Zhanghua city one of like with the most population of Zhanghua county so if if we want to have uh these stories as a kind of cultural map or like those photos like how we did to Leihem and how we did to the tribe so first first question is how to make people to be there like the traffic issue yeah so if we have a cultural map on the mountains how to make the people into the mountains yeah and second about the translation problem like because those stories are not original written in Chinese so will it happen like when you do some translation how to just just like in the in the tv channel if you do the translation how to respect the trip language yeah sometimes the some problem will happen in translation yeah and the final part I said one most important thing part of this who can rest the phone like yeah the money issue yeah so who can suppose these stories as become a kind of cultural industry of village the first one actually um right now many uh many tribes they actually have special vegetable every year for example I know Su Ming actually also participate one in uh for for Amis music festival it's in the mountain but normally the indigenous television news will broadcasting about the tie and place and they sell the ticket so actually quite it's sell sell very quickly because they are a lot of fans they like the music they like to participate uh with the events and if they also have transportation arranged with that so I think it's they are the whole program has been arranged in the proper way and they connect with the news or they have program to uh to introduce different kind of events and sometimes not only uh the tribal culture itself sometimes they also invite uh the singer or the uh the the artists from outside and also they are showing the film not only we see one one tribe sometimes they are different tribes connect together so people actually tour in the whole Taiwan in different tribes so I think they attract people in different ways because they are different kind of art form and different connection it's more like a festival but in uh link with indigenous culture so uh people participate in it uh through different ways so I think for the transportation one right now they do uh put in a more modern form and the second one for the translation uh first of all sometimes people don't care about the language because even you don't know language if you sing the song you don't know language you still can enjoy the song and there are many art form you don't need the language you know how you see how people make all of those are crap so it still attract people not necessarily use the language but in terms of literature I think right now many people actually would like to it's like disney this like people speak English not they use all of the content the stories from global it's not only from one language but you can adapt long story to different kind of language but the most important thing is how do you speak this in this story in a different way with modern concept and that's the one indigenous story or indigenous legend also can be terrifying in this global war and to connect with wider audience the answer all of your question money oh the funding one sometimes the festivals sell the ticket so so they can they don't need sometimes government will support and sometimes they are also some traveling actually don't like to raise the money because they want to keep their original way once they have they have people support and then the economy and political power maybe in France how can they control the whole event and so sometimes some tribe they they prefer just they are a lot of volunteer they can use yeah so when you you like that kind of culture and then you will just go and do it and tribal people sometimes do many things together it's more like community sense so it's not necessary about money but people organize it probably just they like it so they do it yeah thank you my question is because the indigenous people has many different tribes or from your nature we all we only say indigenous people as media so I'm wondering the different type of different language different culture different background how to in in your research how to is the yeah I serve or to clarify or to compare which other or compete which other at this is first question and second questions because actually the government puts a lot of resources on indigenous culture and education like Dong Hua University your students almost quite privileged position in even more produced than the the normal students they normal yeah they get obligate job guarantee some students and also the recently the pts get a biggest budget to make the the tv program sorry I suddenly forgot the the tv program the name of the program I only remember the director is tau rei yuan like drama yeah tv drama recently just start and pts very very big the the story is from a uh uh medical doctor he wrote the the story and talk about how Taiwan the indigenous people is the in the 16th or 17th century to uh first international incident to uh fight with the western to connect so they put a lot of uh uh budget money on this so I I so I don't know why how but it's very um how to say it because on the one hand as you say uh some programs indigenous people do their own from their own uh perspective the program but as I said the pts the director and the novel writer all hand uh people so I don't know what's uh how how about uh we say called indigenous indigenous people how to view this yeah and sorry and then the third question is how do you feel but nice compared in the front of president of this for so long time she continues to do you mean the how the media they'll be changing and how indigenous uh media or people how do this yes um first of all I think when we say indigenous that means very diverse indigenous people and different concept so uh when you are talking about compete is that uh for example like news uh indigenous have certain language uh at least at least certain language uh television news so they separate uh different time for example Monday is for Amis Tuesday is for Taiwan Thursday is for Dao Friday is for like it's different because it's they are not 13 days in the week so one day have different sometimes a large time in Japan yeah and also subtitle sometimes it's like Amis with Chinese title for example five and six and with indigenous like roman spelling is like seven to eight for example like this so uh you got to remember your tribe is which day yeah and sometimes they are showing it because it's it's unfair if only choose one language the bigger group I think for other people they are not happy with that and that's not because it's also important for the in indigenous television news is to sustain different kind of culture of different kind of language so let's uh there are a lot of debate for years about how to program this in the proper way but I think that's so far they did it so this one I'm uh I'm trying to answer the first one but also a program because they are different legend different stories so they can produce with different kind of media for like TV drama or like cartoon or like animation so I just show you some example but there are so many different kind I also feel like the documentary film or like the adaptation type of film so but based on the story of its original legend so they are different kind of media form originally from different kind of story from different tribe so they can we can all see it from the it's indigenous television news is more like a platform but different kind of producer different kind of media form they can all find a place or wait to connect with it so I think that's more like a practical uh usage right now in the indigenous television news and why is that so question I think they just keep reporting it but even indigenous people probably with different point view is not only one way to thinking about how to demonstrate or how to talk at this issue some people agree with that some people with some people not so I think it also depends on the reporter so they are also different kind of social network engage with this issue and some can be very radical but some prefer in a more peaceful way but um but I think it's important to have the chance to make different opinion they all have possibility to show in the television news all program I was going to ask that same question as Charlotte that was my my my my uh my first question but my the other question was about audience so who exactly is uh uh the indigenous TV stations target audience um to what extent can it also reach hand viewers or non-indigenous uh because one of the things that's come up in a lot of the discussion the last three days is misunderstandings lack of interest or lack of awareness of indigenous issues so that leads to the question about how does um indigenous media get into mainstream media so could you comment for example on the relationship between um indigenous TV and other media forms for example public TV or um private media right now I think they actually have some exchanging news program or cooperation way so sometimes some indigenous news also they just change the subtitle and they also show in the mainstream television news not only thematically being used or just pick and choose sorry um because different television programs have different kind of cooperation or sometimes when they see the news they feel it's important they also um also show in the mainstream and also they are it's kind of diaspora of the journalists themselves because they are a lot every time when the chairman of indigenous television news change and they are some reporter will leave but sometimes they leave and then they they just move to the mainstream news so there are some indigenous journalists actually working in the mainstream television they are also producing the news related with indigenous issues so I think that's different ways when sometimes it's programmed exchange itself sometimes the people have been trained in the indigenous news later who work in the mainstream television news so they are more and more awareness about indigenous issue in different kind of channel actually my question was going to be very very similar along the lines of I don't know if this is working but I hope I'm loud enough that it almost feels my thing is like L1 L2 acquisition first and second language acquisition and research shows the two biggest drivers of that are the language being spoken at home which you kind of touched on and extensive materials as we call them in that language which would be like the media and you talked about modernizing it making making it more interesting but also related to David's question it feels a little tokenizing like here's the mainstream news in Mandarin and here's your nice little thing in Bono and oh isn't that cute and how do we mainstreamize that so that it's news for everyone in such a way that we can support language preservation to make it extensive materials that you know that support this and to what extent do we need to also shift our focus on getting older members of various groups to speak their native languages at home which is an issue we see across Taiwan including with Taiwanese in the north Haka people are just not speaking the language to their kids where do we need to emphasize it and how far do you think we've come I don't know I don't think about the answer yeah they right now the education system also trying to provide an environment for example for Indigenous students they are right now they are hoping to provide environment from the family to an elementary school to a university if the whole system with Indigenous languages I think Maori people have already done it but right now they kind of try to adapt this one to Taiwan but we are not quite sure it will be successful or not and that's also part of the reason you are talking about a lot of budget for the education system right now they want to train a lot of like Indigenous language teacher so in my college all of a sudden so many people come to my college and try to become language teacher so the more and more people get to know their own language sometimes they probably can it's more like a small community everywhere in Taiwan so they can train young people and also combine with different how media are born so I think the cultural identity actually strength through all of these efforts no matter from education from from marketing or from different cultural product let's that's how although there are also some people debating with that yeah well research shows that children like children that go to language school even if it's their native language of their culture just do not learn the language the same way as if they've also they're also speaking it at home but without the extensive materials of media for them to watch they're still not going to acquire it so how do we put these all in think to make that happen it's still your responsibility yeah but I've been thinking about the example of Saito Ke Balai after the movie I think Zheng Zhi University actually have a lot of people start to learn uh Saito Ke language there was even a type of times article about it but I went to ask her and she said it was like half a dozen people that expressed interest how many people do you think learned how to speak it that was zero maybe one maybe like one dude was really smart one dude is really okay thanks why don't wait thank you but oh no no he has already cute and then you all right thanks uh I guess mine is a question or some thoughts based on the the previous questions so I'm just thinking that we're talking about indigenous media the issue of that nation is is very important because this this concept is not something that we can just take and for granted so we must ask how should we define indigenous media is it is indigenous media some media that is produced by the indigenous people or is it media that is produced for or consumed by the indigenous people or it's indigenous media something like the media about indigenous people I think this distinction is that could be really helpful because it can links back to the like different parts of the the cultural industry like the production and consumption and representation which will be helpful for like a when they think about like cultural change in terms of the more normative kind of way yeah this is also the issue a lot of debating with that but I think right now it's more like anything related with indigenous issues or if they all including in this concept because for example like indigenous arts some indigenous artists they don't like to be clarify us indigenous artists because although he's he he is indigenous people but he would like to be regarded as like a no artist yeah he don't like to be clarify us indigenous but also they are people stay in the tribe more than 20 years and people just regard them as one of them and so how do you define indigenous it become very confusing in some way and so if you if someone know better knowledge than the indigenous people why not he couldn't be regarded as one kind of indigenous people so what's your definition my definition is if about indigenous media or sorry I think if I will not use the uh identification of in terms of ethnic I will in my because I of course if someone boom as indigenous is indigenous but if someone you do pay attention about indigenous issues and do a lot for indigenous people I will think he can be he or she can be part of indigenous community yeah but you can't change your ID card but yeah but you can probably change to high because can't go the other way according to to yesterday our ways was saying how difficult it is to be categorized us uh indigenous I think we can answer another question is like who is British it's not only yeah so how many is there yeah that's the example of that yeah so indigenous media is not only someone born with indigenous identity I think if he do involve with many indigenous affairs I think he can be regarded as one of the indigenous community yeah I'm happy yes I agree with that last comment but just an intersection with the previous questions about the pluralization and how to represent I think including David's comment about what kind of audiences are being catered for I think one um position that I would suggest that we need to consider is that when we use audience research within a media framework we are liable to reproduce the present or formulations of the present because constructing the audience around a kind of you know what would you like scenario in one form or another will reproduce institutional representation as it is or has been projected so to pluralize particularly within a minority framework we would need more kind of agencies of representation which come from a more grassroots and organic background this has been a particular problem in the UK you know to this day we are unable to pluralize our media despite repetitive attempts to do so and all all of the attempts that we had have always reproduced elite formats in minority groupings and I would imagine that that's something which all of the kind of indigenous communities would be struggling with wow thank you I think it must be a comment right do you want to respond to that I think that's a good comment on that note I think do we have our yes break yes oh oh maybe we have the time to just take one more and sure one please everyone's getting doing this yeah so thank you for your engaging talks so we've talked a lot of media and those are all based on language so that makes me thinking about how about using media without language and I'm sure there is at least one possibility choreography yes and the reason why I think I'm thinking about dance is because um recently there is an institute called a high-ranking dance research institute it's orchestrating a series of conference which are of course dance centered but also it invites scholars priests uh poets filmmakers to give talks in order to preserve cultural identity historical memories and also express political discontents so that makes me thinking about the possibility of using bodies dance as a platform to express and preserve these cultural identity so could it be a possibility yeah yeah I think in dance is always important for indigenous culture and I think the indigenous news also reporting a lot of related issues and I think for indigenous people sometimes music and dance also convey a lot of history and and uh uh the cultural background with that so that's why uh in for example there's one one news I didn't show you for example like uh benan tribe in the during the next land new years festival they dance overnight but when they dance overnight is they are showing the whole history so the dance itself is contained in history through dance they just generation by generation to that the younger people understand their own culture and also the singing the singing also no languages yeah that's no language but the the singing even the song itself with a lot of meaning like when they do hunting they have different kind of like different kind of shouting but those different kind of shouting means something different so people can understand people can understand what does that mean there's no language at all but of course it says a lot for about their culture actually yeah sorry we have one more question very sure very sure he's promised me that's not actually a question oh another comment a comment and a comment for to to uh sorry what's your name oh that's very rude what's your name yeah to his uh comment uh I can uh how to say um make it more specific and uh yeah uh yeah uh suming came to germany to berlin actually two years ago and what we have done is picnic and then we've done in a circle with german people and yeah taiwanese fans and even though we don't understand the language we have german interpretive and english interpretive at the same time so yeah no we don't thank you but actually wien wu jia since 1990 so it's not like only cherry okay okay on that note thank you so much and thanks uh uh you know fantastic talk again


What's good George Royce back at again with another video? So we got to talk about Tony Khan releasing a statement on Twitter about the whole Jeff Hardy situation, and I'm gonna get my thoughts opinions on what was said here Yeah, man, the whole situation is just unfortunate and sad But I'll talk about that at the end of me reading his statement. So on Tony Khan's Twitter, he Released a statement saying we were able to resume contact with Jeff Hardy this afternoon AW does not condone Jeff Jeff's alleged behavior We made it clear to Jeff that we will assist them and get a treatment for substance abuse issues Which he had has indicated that he's open to receiving in the interim He is suspended without pay and he can only return to AEW upon successfully completing treatment and maintaining his sobriety if you or a loved one needs help, please reach out to SAA in HSA's national helpline 1-800-662-HELP or 4357 by Tony Khan Um This is I'll find a silver lining in this situation. I'm glad that they were you or what they were able to you know make some type of I guess you can say Communication with Jeff I would not Contact with Jeff, but he needs he needs help there He he needs help in Getting his situation together now some people are blaming Tony Khan for this like oh you should have known about this You know before you you hire them and all this other stuff and I don't I don't think Tony should be receiving any blame I don't think anyone else should be receiving any blame Other than Jeff Hardy himself. Jeff Hardy should be the only person that takes full responsibility for what he did. I Know there were reports before Jeff left that WWE was trying to get him help because you know that last match he had he was kind of he was kind of off Oh, and I he was saying he was fine. He was good then and Now this happens, you know, maybe he was good at the time Maybe he wasn't you know under the influence or wasn't really, you know, I guess you could say Like Dylan dealing with a lot, I'm not sure I'm not him I wasn't there but it seems as if his old demons have come back and it's just one of those things where it's like There's only so much you can do as a owner. There's only so much you can do as Friends, there's only so much you can do as family members There's only so much we can do as fans we can help for the best for Jeff But he has to want that he has to want the help he has to want to change because this is like the third time This has happened and this is not good. No, WWE has released them before because of this That was one of the reasons Hell they made it a storyline at one point a few times actually so I Don't know. It's like Jeff will get to a point Even in the past he's kind of derailed his push Sometimes because of these these things because of what he's dealing with And I'm all for everyone having you know trying to be empathetic But I'm also on the side of there's only so many times you can be empathetic towards someone Before it's like I you gotta make some type of change if you don't want to make a change then I Don't know man. You made me. I don't know You may need to step away from his wrestling thing You may need to get some help something because what you're doing now. It's not helping you It's not helping your loved ones. It's not helping your fans.  So what Tony Khan did here? Understandable. He's he's he suspended without pay. You shouldn't be rewarded for Behavior like that that you constantly have been doing. This is not a one-time thing You did this is WWE now. You're doing this in AEW. I believe I'm not sure correct me if I'm wrong But I believe there was an incident he had in TNA as well. I think he was like Like he wasn't himself like I think he was I think I think he may have been Drunk like there was a match where he was like messed up correct me if I'm wrong But I believe he did have an incident in TNA and it's it's it's not just the companies now You gotta put start taking responsibility So I hope he's able to get the help he need and I hope he's able to complete the course the Treatment and remain sober. Don't don't give him. No, don't even talk about alcohol around him This and he needs to remain sober and if that means, you know, he has to step away for a while Then that's more important than wrestling Cuz this is just not looking too good, so I don't think people should be blaming Tony Khan for this I think this that's immature. I think you're missing the point Tony Khan has no control over what people do All he does is signs of checks and you know, he has control over the booking situations But he doesn't control what they do on their off-time Come on. Even if he knew knew about his, you know prior debits He was still willing to give him a chance And the Vinces does the same thing too And as fans we always want to give Jeff Hardy the chance to prove us wrong and and you know Stay on the straight narrow, but sometimes people have to want it themselves, man But comment down below. Let me know what you guys think should should happen Do you I still want to know you guys think he should Even after the treatment after he does take treatment Do you think he should come back to wrestling or do you think it's time for Jeff Hardy to hang it up? Let me know down below. I really want to start a discussion there, but I'm wishing the best for Jeff man praying for you, bro You got to get some help because this is getting out of here And I'm God forbid something happens to him or someone else I would not want to hear news about that. So I read that he get the help he needs now That way we can move forward if he decides to continue to wrestle or if he decides to hang it up But I appreciate all love and support road to 90k appreciate talking to me see our next piece


In the last lecture we had used only linear elements in negative feedback along with the op amp and seen how integrators differentiators and instrumentation amplifiers can be built. In today's lecture 19th lecture we will be discussing the use of op amp in negative feedback we using non-linear devices like diodes and transistors to form what are called as non-linear circuit non-linear signal processing activities. So let us see what we had done in the last class we had instrumentation amplifier one of the important applications integrator one of the most important building blocks in filters differentiators time markers effect of finite gain menu product on the performance of these important building blocks. Today we will be discussing the association of non-linear elements like diode and transistors both MOS and bipolar in signal processing activities. Let us now consider a half wave rectifier using a single diode semiconductor diode PN junction diode and resistor. So we have the source generating a sine wave let us say this is the 50 hertz wave so that is getting generated with some peak magnitude VP. So if this is VP sine omega t into 50. So what is the kind of waveform that should appear here. So if VP is of the order of let us say 1 volt then up to about 0.7 the diode does not conduct the cut in voltage V gamma that is what it is about 0.7 the diode does not conduct only thereafter it conducts. So what happens we have the input waveform okay coming like this and the output waveform will be appearing it is conducting only for a portion of the cycle and this portion of the waveform appears okay at the output. So we get at the output instead of the half wave rectification that we expect right we get only portion of the half wave as the output which is roughly equal to VP – V gamma. So as up to V gamma it does not conduct. So this is because of the fact that I flows only after VP crosses okay I is greater than 0 only when VP that is VP should be greater than V gamma and beyond V gamma okay that is VI okay greater than V gamma it conducts. So let us look at the transfer characteristic now it is linear and non-linear the diode starts conducting okay really speaking around 0.6 to 0.7 volts you can see of course it is not abrupt there is a smooth change okay it is exponential characteristics for the diode. So this current is changing gradually from 0 up to the full value and thereafter okay is going on increasing okay as VP – V gamma by R or V – V gamma by R that is the current beyond V that is V gamma this is the transfer characteristic this is the waveform simulated waveform. So VP has been taken as 1 volt so you can see that roughly VP – 0.6 or so right is the that is 0.4 also right is the amplitude of the peak that has been obtained. So that is the distortion that it is suffering because it is a non-linear resistance. So it is not exactly the sine wave it was earlier so this is what happens now you just see what happens so it has a limited amount of conduction over the half cycle also and it is not exactly the sine wave it is. Now this same diode in series with this resistance is now having the op amp in negative feedback so what happens this is still the same input VP sin omega t and VP is still equal to let us say 1 volt. So now what happens up to until the output voltage of this right goes to V naught dash goes to V gamma with respect to ground the diode does not conduct. However as long as the diode does not conduct there is no feedback so this op amp is in open loop okay so one end is grounded and VI is going on increasing so the moment VI increases by few under of micro volts even the output goes to saturation right because of the high gain of the IDC gain of the op amp. So when it is attempting to go to saturation let us say it is going positive okay because this is going positive during this portion here it goes negative so during this portion is going positive just when it crosses zero this jumps to V gamma and thereafter okay the diode is conducting okay so the diode starts conducting at that point of time so there is a jump so at this point there is a jump thereafter the diode is conducting and then the rest of the voltage is driving a current through the load okay so the rest of the voltage is going to appear okay so this is the kind of jump that is going to suffer that means we have the entire voltage waveform okay that is going to be reproduced this may be the current sort of the current is zero until certain point of time and then it is conducting so this is the kind of waveform that one expects at the output okay so as far as the negative going cycle is concerned the path is always broken the diode is not conducting and therefore this is in open loop goes to a negative saturation okay so this is the kind of output you should expect from this thing however if you look at the point here as far as V naught is concerned V naught is going to be just this with this being restricted to zero because of the fact that this is open and here we have RL maintaining the ground potential zero so op amp is disconnected during this time so this is the kind of output that we expect from the sub favorite to fail so this output is going to be followed exactly and this is what we see during the negative half of the cycle so let us see the simulation results the transfer characteristic is exactly the precision rectifier characteristic where it is conducting immediately around zero itself and output is linearly related to input with the slope equal to 1 so we have this output following the input okay it is a voltage follower only during the time when the diode is conducting and therefore this is the transfer characteristic whereas you would have seen that the transfer characteristic was pretty distorted for the case of just diode without any negative feedback this was the characteristic so we see that precision rectifier can be easily built by incorporating it in negative feedback this is the input and the output of the op amp has jumped okay and on the other side up to V gamma on this side and has jumped up to the saturation on the other side that is why it looks like a square waveform and maintains the actual output across the load as precisely half wave rectification so this is how it becomes a precision rectifier now let us to see another topology where we have used it in negative feedback in this mode this is nothing but the trans resistance amplifier the voltage is then converted input voltage is converted to current and we can see that the current here is Vi by R so this is going to conduct the diode is going to conduct only for Vi greater than zero so the moment diode conducts this current is going to flow through this this potential is virtual ground that means nearly zero okay and this current is going to be Vi by R and the potential developed across this R is same as Vi and therefore this voltage being zero output voltage if you take at this point that is where the load is connected so V naught is going to be equal to Vi for Vi greater than zero so it is exactly the positive going half which is reproduced with the same value of VP as Vi so this is V naught thereafter the diode is not going to conduct for the negative going half of the input voltage so what happens when the diode is not conducting this is open feedback is not existing op amp simply goes to positive saturation so the op amp jumps okay up to the positive saturation whenever input Vi is going negative. So output voltage here is going to be simply you can see the path for the current this is open so the path for the current is this that means output voltage is going to be RL into VP divided by RL plus 2R simply an attenuator so this is the output voltage if RL is very large it will be simply that is going to be Vi negative right so actually speaking we have here V naught for this time is going to be going negative and during this period it is going to be some value which is decided by what the value of RL is that means this always going to minus VP because of the inversion plus minus V naught is equal to minus Vi right so it is going up to minus VP every time the input is going positive output will go negative this is V naught and as far as this is concerned this is determined by VP into RL by RL plus 2R this is because the current has to come from input only earlier the current was coming from the op amp itself for both the load as well as the load okay as well as this current they will have to come from the op amp okay in this cycle whereas in here the current is coming from okay the input itself so it is going on changing with RL so it looks like a full wave rectifier only when RL is very large whereas when RL is small it is looking like a half wave rectifier it depends upon RL so this is not good as a half wave rectifier whereas it is transfer characteristic also is not exactly as that of the full wave half wave rectifier nor is it a full wave rectifier because this is dependent upon the load this is independent of load okay and the output you can see this is the half wave that is produced okay during the positive going input and this is the wave it produces during negative going input and this magnitude is dependent upon RL that is shown for different values of RL so it becomes a full wave like thing okay for large value of RL and half wave like thing for low value of RL so this can be got rid of okay and we can get precisely the correct waveform okay by introducing a feedback path okay during the other half also so for positive going this diode conducts and for negative going this diode conducts and maintains this potential at this point okay at ground potential so that the voltage if it is taken here for the output this is going to produce for positive going cycle okay this will produce a negative going waveform and zero okay at the output maintained by the feedback during the other half of the cycle that is negative going input and if you take the output here it will be that it will give you the positive going output during the negative half of the input so this this kind of half wave rectification okay outputs can be got here at this point and this point this is the negative going half wave that is the positive going half wave okay if you subtract these 2 voltages you will get the full wave that subtractor can be a different amplifier so you can see the transfer characteristic here this is one output and this is the other output this so these are the 2 half wave rectifier outputs possible okay and for getting a half wave you have to use 2 diodes with this trans resistor type of feedback and this is precisely what happens between V01 and V02 for the positive going input negative half and for the negative going the positive half so this is the full wave rectifier this is its output now let us see how the same similar application can be carried out with diode in the feedback path okay only thing is for in the previous circuit we had the resistor here and the diode was here so I have just interchanged the position of diode and resistor of my rectifier circuit incorporating op amp so what happens now this becomes a logarithmic amplifier what is a logarithmic amplifier log can do an operation of data compression so this is data compression data expander put in a negative feedback path gives data compression so if you see a diode okay diode has a relationship of data expansion current is equal to IS exponent V diode by VT this is the diode characteristic this is data expansion if it is put in the feedback path we should get as far as input of the op amp is concerned voltage VI is converted to current of VI by R this current is the one that is now flowing and that is the diode current so I diode is equal to VI by R that has been forced by the op amp trans resistance amplifier so we have here V naught is equal to minus V diode this is 0 okay this is V diode so the condition is VI has to be greater than 0 positive always for such an operation V naught is going to be minus VD and is equal to minus VT log from this expression VI by IS into R okay so it is the inverse operation this I had already pointed out and discussing about system level negative feedback operations so this is a log operation unfortunately IS is okay the reverse saturation current and it is doubling every 10 degree rise in temperature VT on the other hand is an absolute constant KT over Q it is 26 millivolts at 300 degree Kelvin precisely defined however IS is changing a lot with temperature and therefore it requires temperature compensation for it to be used as a data compressor this is the data compression activity it is carrying out so you can see that 100 millivolts to one volt a decade of variation of input voltage is compressed into very nearly let us say 325 millivolts to about 500 millivolts so this is the data compression activity of this particular structure now let us see how this can be the diode can be replaced by a transistor bipolar transistor okay and it does the same function again the circuit as the diode replaced by a bipolar transistor okay with base connected to ground in a negative feedback topology so what this is nothing but this is the first instance of our coming up with the feedback which is active look at this the output of the amplifier is going as input to the common base structure and the output current is going as feedback at this point at the input so this is the current feedback I am talking about so it is a current follower at this point and therefore VI by R is same as the current of the collector that means emitter base voltage has to so adjust itself to make this current same as the input current VI by R so the voltage that is developed here the dependent voltage developed across this is nothing but – VT log VI by R E naught that is because we have again the well known expression what is it I of the transistor right so I emitter is equal to I E naught reverse saturation current of the transistor emitter base junction exponent VBE by VT this we had already discussed when we are discussing the transistors so the output voltage is equal to – VT log VI by R into I E naught instead of IS of the diode we are replacing it by the I E naught the base emitter junction diode reverse saturation current for VI greater than 0 this is what happens so this works only for VI greater than 0 this transistor base log amplifiers transfer characteristic is similar to what we saw with the diode again 100 millivolts to 1 volt one decade variation in input voltage is converted to 520 millivolts to about 620 that means a decade variation per 100 millivolts variation one a decade variation per volt compression now what happens here just let us see this is an active feedback that means earlier we had used this op amp with attenuators in feedback or capacitor in feedback and resistor in feedback however in this case we are using a transistor amplifier which is a common base transistor amplifier so the gain of this is going to be nothing but the collector resistances are you ground this so in the loop you have a common base transistor amplifier okay so the phase shift from here to here is 0 and therefore this is still negative feedback now the gain of this is if this is GM okay this is R the gain of this is GM into R so the open loop gain of this system in feedback is going to be A of this which is typically closely equal to G by VB by us but now there is a DC gain A naught okay that into GM into R that is the modified gain is the negative sign indicating it is negative feedback so the open loop DC gain has been perhaps enhanced by this so this has been actually if you use an internally compensated op amp we had seen like 741 this has been compensated for unity gain right feedback amplifier so it has been compensated for A naught as the DC gain okay with this completely coming to here at the input whereas we have now amplified it by GM R and feeding it back so the DC gain had been enhanced so the Q gets enhanced by route of this GM into R so you can see that since Q has been made equal to 1 for unity gain topology using the second pole into account okay along with GB already this GM into R will enhance the Q into a higher value of root of GM into R times 1 so that is what has sampled okay in the dynamic operation of this device this particular op amp with this kind of feedback is having very high Q so you can see that noise is produced here okay and it is ringing at this particular point okay and it requires frequency compensation how can we be resurrect this operation of this negative feedback stage into making Q equal to 1 for this loop now so I just put a series resistance here so that the gain gets reduced okay now to R by RE from GM into R so if R is right equal to RE then the gain is roughly R by RE okay which is equal to 1 so we have now got back the value of Q equal to 1 for this new loop now okay using the same op amp says 7 for 1 so that means that is what we have done okay in the simulation and we made RE equal to 1K for RE equal to 1K and immediately we saw that it is precisely the input waveform so input is changed okay from let us say very low value okay to a high value okay so an input is a square wave now output also is a square wave but data compressed okay so input is changed from say 100 millivolts to 1 volt and this changes 10 by this amount so you can see this ringing here or the oscillation right because of ringing is stopped by reducing the gain of the active feedback network so this is the effect of compensation of a log amplifier now same circuit okay instead of the RE here I am putting an attenuator R1 by R1 plus R2 so the output will adjust itself so that the same voltage that is appearing here is enhanced by a factor of 1 plus R2 over R1 okay so that is what happens minus VT log VI by IE naught R gets amplified by 1 plus R2 over R1 simultaneously if I make R1 parallel R2 okay equal to the let us say the R or R1 parallel R2 into GM into R1 by R1 plus R2 into the gain here okay is such that this whole thing is going to be having Q equal to 1 then also the frequency compensation is possible. So this is the technique of making use of an attenuator here instead of just a series resistance right to obtain simultaneously amplified portion of the log amplifier and also okay bringing down the Q of the system to bringing it back to 1 now temperature compensation obviously this term is heavily dependent upon temperature IE naught double for every 10 degree rise in temperature how to compensate for this. So in order to practically use this log amplifier what is done is simply the same operation is carried out now VI by R still flows here okay so we have this still equal to VI by R that means this voltage is still equal to VT log VI by R with the negative sign okay but I do not take the output there instead I take the output let us say V naught prime here and V naught here what is V naught prime this is another similar negative feedback structure with the transistor in feedback path and I am injecting a current of VR by R here. So the collector current of this transistor has to be VR by that means this voltage will adjust itself what is the voltage V this is T1 let us say this is T2 so T1 VBE1 is nothing but okay say the same thing earlier it is minus VT log VI by R IE naught whereas VBE2 it is a negative feedback amplifier here okay so this has to adjust itself so that this current collector current is VR by R that means this VBE2 is now minus VT log VR reference voltage that I can fix conveniently by R into same IE naught assumption is these two are perfectly matched which is easily achieved if you purchase a matched pair which is obtained in integrated circuits. So if these two voltages are now going to be appearing here as V naught prime is nothing but okay minus VT log VI R IE naught plus VT log VR by R IE naught so this essentially becomes V naught prime so V naught prime is okay minus VT log VI divided by these two get cancelled. So that is how you are compensating for IE naught dependence by using a matched diode okay which is the emitter based junction of T1 and emitter based junction of T2. So once V naught dash is independent of IE naught we are amplifying it by the same factor 1 plus R2 over R1 R1 by R1 plus R2 is the attenuator so the V naught will adjust itself to be 1 plus R2 over R1 into log VI by VR into VT. So this now is totally independent of IE naught effect and these factors can be adjusted by our design set that this sensitivity of this particular log amplifier is whatever precisely we want to have. So such log amplifiers are readily available in the market okay and one such log amplifier is log 2 1 1 2 by TI commercial log amplifier you can see the matched pair Q1 Q2 here okay and the this is the input sort of log amplifier this is the reference log amplifier together with the attenuator with the output there is a spare op amp which can amplify it further okay. So these are the characteristics parameters of such log amplifier input current range from you can see the nano amperes to milli amperes okay 1 nano ampere to 3.5 milli ampere change several decades okay. So initial 5 decades okay error is only 0.2% okay this is the variation in temperature offset voltage is maximum of 1.5 milli volts only. So power supply limitation okay and internally the reference is generated okay auxiliary op amp is one more okay this is the voltage range where the data gets compressed.  So this is the inverse operation that we are now performing obviously a diode itself is a data expander you can see that most of the input voltage ranges only of the order of 100s of milli volts as far as the diode is concerned when it is forward biased okay and the current can be varying in decades. So basically a diode is a data expander so you put a diode okay the input of such trans resistor amplifier here this is nothing but a trans resistor amplifier. So it just converts the current of this diode into voltage that is all its function is to convert the current into voltage. So as far as the data expansion activity is concerned it is directly that of the diode. So V naught is equal to once again minus IS exponent VI by VT which is the current of the diode passing through the resistance R develops a potential minus IS into R exponent VI by VT for VI greater than 0 this is the function of the data expander okay. So this if data compressor is the coder data expander is the decoder right. So if you are using it for data compression and data expansion we do not have to worry about temperature compensation precisely right because the same IS okay is being used for both data expansion as well as data compression and therefore the cancel naturally occurs okay. So replacing it by a transistor the diode is replaced by a transistor here and we have the transistor input a transistor therefore is nothing but a data expander only in terms of output in current and input being voltage this is straight away the function. So a bipolar transistor is a data expander by itself and that link to a trans resistance amplifiers in op amp will give us nothing but a voltage conversion of that current okay and this is precisely the data expander. So the role of op amp is only to convert it into voltage here again this does not need any specialized care for frequency compensation because this is already frequency compensated for full feedback so it is going to remain the same Q equal to 1 as far as this is concerned whatever be the input voltage or voltage to current conversion factor so it is totally independent of the input stage. So this is the transfer function data expansion occurs okay this expansion now this also needs precise frequency compensation because IE naught comes into picture if this is going to be used as a standalone data expansion function. So what is done is we generate a current of V reference by R so this feedback system is that this current gets fixed collector current gets fixed that means this voltage is fixed as okay minus VT log okay V reference by R into IE naught. So then that voltage along with the voltage okay this voltage okay plus this voltage what is that voltage this voltage is precisely equal to VI into R1 by R1 plus R2.  So if you now apply this right the output current of this is going to be IE naught exponent this VBE. So this VBE involves this voltage which is precisely what we want okay so that will come as output and exponent minus VT log VR by R IE naught will give you a voltage of R IE naught by VR to this therefore we just get V reference IE naught gets cancelled with IE naught okay. So once you substitute it here right you will see that the output voltage is going to be precisely this. So this is the way the effect of IE naught can be compensated. So you can see that this current now gets through this resistance R and develops an output voltage which is actually the current is in the other direction this way so this is plus minus so output is positive V reference exponent R1 by R1 plus R2 into VI by VT okay. So this is the way we can obtain compensated exponential amplifier for our application okay. So the output voltage is this into R into IE naught so IE naught gets cancelled with this R into IE naught okay. So that V reference becomes precisely what we want that V naught becomes precisely equal to V reference into exponent R1 by R1 plus R2 into VI by VT. Now this is a combined application of log amplifier and anti-log amplifier to form what is called analog multiplier. So this is the circuit of analog multiplier this is one of the important applications of this log anti-log amplifiers analog multiplier. We have referred to this as an important basic building block in analog signal processing earlier and also shown some of the users of this multiplier as a phase detector and mixer modulator AM modulator etc. So now let us see how such a multiplier can be built. So we have here IX that is the current input to all this trans impedance amplifiers okay. So this current input is going to force a current of IX exactly in the collector of this so this voltage is going to be – VT log IX by IE naught that is because of the feedback here this RE1 is meant for making the frequency compensation okay ahh such that Q of the system is one that we had already seen in the earlier design. Now we have IY forcing the collector current of the other transistor which is having its base emitter in series with the previous one so that these two voltages add. So this current will force this voltage to be – VT log IY by IE naught. So these two voltages are added and therefore the effective voltage at this point is going to be equal to – VT log IX into IY by IE naught square. So this is the voltage here that is applied as input voltage to these two transistors. Let us see what these voltages are. This is again a similar feedback network as earlier like this but it has IR coming through is so this is IR so this is going to be – VT log IR divided by IE naught okay and therefore this is going to be therefore a voltage which is this voltage okay it is – VT okay plus okay so at this point we have a voltage across this which is this voltage – this voltage okay or the positive voltage between this and this for this transistor is going to be nothing but VT log for this transistor I there is positive voltage is going to be this okay this – this okay so it is going to be – VT log IR by IE naught okay plus VT log IX IY by IE naught square. So effectively the voltage across this is going to be VT log okay IX IY by IR this – this okay divided by IE naught. So that is the VBE of this so exponent okay VBE divided by VT into IE naught into IE naught is the current in this I naught that is equal to I naught. So what it is this gets cancelled exponent of log is same as IX IY by IR IE naught IE naught gets cancelled with IE naught okay so this current is going to be precisely IX IY by IR okay that flows through this and develops a potential R into IX IY so that is the output voltage. So we have a multiplier and divider so multiplier come divider already generated with IX IY IR all as positive so this is a single quadrant multiplier come divider is one of the cheapest multiplier that one can build okay and convert it into four quadrant okay when necessary and it has a variety of application in communication signal processing okay and log it is used in communication analytical medical industrial test and general instrumentation okay in opto coupler isolation these log amplifiers are the parts that are normally used analog signal compression. So the photo diode or opto coupler okay is one such data compressor and data expander. So let us look at this opto coupler okay here the this is the data expander okay this is the data compressor so data compressor with data expander okay is what is going to give you some kind of okay linear relationship IE what is going through this LED this is what is called an opto coupler okay and this is the photo transistor. So you can see that this is grounded this is going to be a 0 if this is a negative feedback now you can see a different kind of feedback where this current gets converted as light here through this LED and gets impregnated on this photo transistor and proportionate current gets generated here and this is the negative feedback structure such that this current is precisely equal to this current so that this potential is maintained at 0. So this is current feedback okay so what happens here is that if this photo diodes are exactly identical this current gets exactly reproduced at this point because this is K I this K may depend upon temperature etc but this K tracks with this K that is what is assumed because these are matched pairs of after isolators. So this will generate the same value of K I okay that it has here such as to make this is exactly equal to K I okay so that is the feedback okay which is optical feedback okay associated with the op-amp now so it converts current to light light to current in a loop okay again this loop has to have Q equal to 1 if the design has to work at high speed. So this voltage now if you take it is I into R and it is precisely reproducing the I in let us say this is put in a high voltage environment like a motor or transformer somewhere right. So you want to measure that current leakage current or something of high voltage circuit. So these voltage isolation can be few kilo volts okay this is the measuring circuit as this precisely measures this I here as a voltage one of the applications of optocouplers or isolation amplifiers okay. So in conclusion we have seen how op-amp can be used in negative feedback along with active devices which are non-linear exponential function generators okay in order to get a precise measurement of currents in high voltage circuits okay for data compression activities in data converters etc right particularly I would say I as a transducer human eye let us say as excellent ability of compressing data that the light impinging on the eye okay the intensity okay etc can be precisely known okay from very high bright light to very low dark light. So most of the signal processing activity occurs at the transducer level itself because of the data compression ability of the sensor okay. So that is the coding that is done okay electronically by let us say opto that is diode which is a photo diode or a photo transistor okay. So it is doing a data expansion okay which is converted into data compression if it is put in the feedback part. So now actually speaking we have discussed this kind of circuit already in terms of transistors themselves we have seen that this transistor let us say if it is a bipolar okay if this is VI this current is going to be IE0 exponent VI by VT so it is a data expander okay if you put it in a feedback loop there is full feedback of output current back to input it is a current follower this current is exactly followed here okay. So it becomes if this is II this becomes V0 which is – VT log II exactly same as what we have done with op amp itself without op amp itself it is doing this operation of logarithmic function right okay and then if you therefore combine this okay like this you put a data compressor along with the data expander you get a perfectly linear function okay if these two are identical okay I0 is going to be equal to II this is the basic current mirror. So you can see that current mirror uses similar compensation technique okay to get rid of the variation of IE0 okay in the overall operation of reflecting the output current as equal to exactly equal to input current if these two are perfectly matched. So this is a data compressor and this is a data expander same thing can be said with MOS also it does not make any difference this is a data expander but it is not so efficient as a transistor so we have here K by 2 VI – VT whole square that is a data expander if you put it in feedback this is II so V0 is this is equal to VT plus root of II by K square root okay that is the data compressor right. So you put data compressor along with data expander again get the current mirror. So these are the signal processing activities by using non-linear devices and getting inverse non-linearity you can get perfect linearity covering decays of variation of signal okay it may be current or voltage does not matter okay. So this is the way you can design systems which are perfectly linear in spite of their non-linearity dependence on temperature etc.