인터넷 영상회의의 흐름제어를 위한 H.261의 압축율 분석

고동환(Dong-hwan Ko),고민수(Min-su Ko),안종석(Jong-Suk Ahn) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.25 No.2Ⅲ

최근 인터넷 상에서의 효율적인 영상/음성 시스템을 개발하려는 연구가 활발히 진행되고 있다. 이러한 연구 중의 중요한 분야로는 인터넷의 대역폭을 효율적으로 사용하려는, 즉 가변적인 인터넷의 사용가능한 대역폭을 예측하고, 예측된 대역폭에 알맞게 영상과 음성 정보를 압축하는 연구일 것이다. 본 논문에서는 사용 가능한 대역폭 예측에 알맞게 영상정보의 압축률을 조절하는 기법을 소개한다. 본 논문에서는 영상 압축 알고리즘의 하나인 H.261에서 압축률에 관련된 변수 값과 다양한 영상에서의 압축율 변화의 상관관계를 측정하였다. 또한 본 논문에서는 측정된 상관관계를 수식화하고, 이 수식을 어떻게 전송량 조절(flow control) 알고리즘에 사용할 것인가를 제안한다.

[자유기고] Autodesk ECOTECT Analysis 2010을 이용한 친환경 건축물 평가 및 분석

고동환(Ko Dong-Hwan) 대한건축학회 2010 建築 Vol.54 No.7

한국 도시사 연구동향

高東煥(Ko Dong-hwan) 역사학회 2010 역사학보 Vol.0 No.207

Studies on Gaegyeong mainly included city facility, space, principles of city construction, the state of Gaeseongbu, formation of the city administration and a life history. On the other hand, studies on Hanyang mainly focused on the formation and development of Hanyang, and transition to a contemporary city. However, in-depth studies on principles of city construction, specific city space, and principles of dividing spaces, administrative organizations, labor service system, urban problems and city culture are conducted recently. In order to develop urban history studies on Gaegyeong and Hanyang, it is necessary to examine urban space, human beings and their correlation. For this purpose, materials such as pictures, folk materials, oral materials, etc. should be used more broadly. In addition, it is required to conduct a comparative study on premodern Korean cities and East Asian cities.

조선시대 한양의 수도성

고동환(Ko Dong-hwan) 역사학회 2011 역사학보 Vol.0 No.209

Hanyang 漢陽 remained the only and one capital in the course of the entire Joseon dynasty. There existed no city in the country that rivalled Hanyang in terms of administrative systems and population size. Although there had a time during the early Joseon dynasty when Gaeseong 開城 functioned as an auxiliary capital, it gradually lost its ground with the stabilization of political primacy of the capital city of Hanyang. During the reign of King Jeongjo, Suwon Hwaseong 水原華城 was built as an auxiliary capital under the idea of operating a dual-capital system. The plan however was thwarted by the precocious death of King Jeongjo. It was during the Korean Empire period at the end of the 19th century that the dual-capital system was actualized with Pyeongyang as West Capital 西京. In the pre-modern East Asia, the capital city had been conceived as the earthly reflection of the heavenly order. In this sense, topography and spatial representation of capital cities were regulated in many ways. As the city of Hanyang had to be built in consideration its natural environment, it was inevitable that the ideal of embodying heavenly order on earth was implemented to a limited extent in the city's construction. The fact that Hanyang had to remain as mere one of vassal cities subject to the Sinocentric world-order played a decisive role in constraining severely the possibilities of expressing the dignity and prestige appropriate to a capital city. And they were further weakened and restricted by the power of aristocratic Yangban, whose control extended to the point that it restricted the central power of the Kingship itself. Hence the one particular feature in spatial representation of the capital city that the royal palace conceded its demand of the centrality to the places where people used to gather such as bell tower and market place.

조선후기 島嶼政策과 元山島의 변화

高東煥(Ko Dong-Hwan) 호서사학회 2006 역사와 담론 Vol.0 No.45

조선후기 서울 도시공간의 변동

고동환(Ko, Dong-Hwan) 서울시립대학교 서울학연구소 2013 서울학연구 Vol.- No.52

In the 18th century Seoul changed its urban culture in line with the transformation as a commercial city from the capital city of the medieval period. Accordingly, various types of areas with new functions had appeared. Along with the commercial development, the commercial center was expanded from one place at Sijeongsangga in Jongno to Chilpae, Yihyeon and Gyeonggang area. As citizens could have economic wealth and leisure culture, a kind of entertainment culture appeared together with the commercialization of entertainment and the amusement culture. And, a commercial agricultural area was formed at the suburban area. And the handcraft shops were formed collectively in Jongno, a center of commerce. Since the late 18th century, the center of Seoul urban space was a commercial area surrounding Jongnu. This area was an entertainment and commercial amusement area as well as handcraft production area. Areas outside the city wall became specialized for commercial agriculture and amusement zones. As such, the urban pace of Seoul was functionally divided according to the commercial development and the formation of urban culture. While the ritual functions including palaces, administrative offices, royal shrine and royal tomb remained, its significant status as a central place for the royal capital in the medieval tradition, citizens in Seoul enjoyed urban life based on commercial places.

메신저 내 그룹 대화방 문서 클러스터링 적용을 위한 클러스터 모델 비교

고동환(Dong-Hwan Ko),김홍준(Hong-Jun Kim) 한국지능시스템학회 2018 한국지능시스템학회논문지 Vol.28 No.2

본 논문은 메신저 상의 유사한 그룹의 사용자들에게 보다 효율적으로 서비스를 제공하기 위해 메신저 상의 대화방들을 문서 클러스터링 방법을 통해 클러스터링 할 때, 채팅 로그 데이터에 적절한 클러스터링 알고리즘을 테스트를 통해 찾는다. 대화방과 채팅 로그의 관계를 문서 클러스터링에서의 문서와 문서 내용의 관계로 대응시킨다. 사전에 준비된 3개 주제의 채팅 로그에 DBSCAN, k-means, Ward’s method 알고리즘을 대화방의 수, 가중치 부여 방식을 달리하여 적용한 뒤 올바르게 분류된 정도를 나타내는 Rand index 수치, 처리 속도, 그리고 모델에 따른 특징을 고려하여 적절한 정도를 평가한다. k-means 알고리즘은 클러스터의 수를 미리 정해야 하는 문제로 메신저에 사용하기 부적절해 보이며, DBSCAN은 Rand index의 평균이 가장 높은 수치를 보였으나 알고리즘 내 인수를 정하는 문제를 해결할 필요가 있다. Ward’s method는 특별한 인수 없이 사용 가능한 장점이 있으며, 가중치 부여 방식에 관계없이 Rand index가 0.9 전후로 좋은 결과를 보인다. In this paper, text clustering models are compared and analyzed for chat rooms on messenger applications to provide appropriate service more effectively. We deal with the relation between the chat room and the chat log as corresponding to the relation the relation between the document and the content for the document clustering. First, DBSCAN, k-means, Ward’s method are used to cluster chat rooms based on chat logs with various number of chat rooms and weighting methods such as TF, TF-IDF, etc. Then we evaluate the quality of clustering results with the value of Rand index that indicate the degree of correct classification. In addition, execution times are measured, and the characteristics of clustering models utilized chat logs are considered. Since the k-means algorithm need to determine the number of clusters before clustering, it is inappropriate for clustering the chat rooms. On the other hand, the result of DBSCAN showed the highest Rand index, however the process to search the optimal epsilon is needed. Ward’s method require no additional work for the optimal argument, and the result of this method have about 0.9 Rand index regardless of the weighting methods.

旅菴 申景濬의 학문과 사상

고동환(Ko Dong-hwan) 역사문화학회 2003 지방사와 지방문화 Vol.6 No.2

Shin Gyeong Jun was a scholar, and also an official who passed the national examination at the age of 43 and served in the government for 26 years. He is known to have been extremely well versed in almost every academical areas, and that assessment is shared by not only his colleagues back then but also the researchers studying them today. But the word ‘well-versed’ feels somewhat lacking in describing his expertise or the nature of his studies. He had a color of his own, and that color is very evident in everything he left, his thoughts, his philosophies regarding his own studies, and most importantly, the academical researches he conducted throughout his life. He had a critical point of view against the dogmatism of Neo-Confucianism which was placing legitimacy and formality above all else, and felt that the so-called heretic Buddhist and Taoist philosophies, or the ancient Chinese ‘Hundreds of School of Thoughts’ can all be useful in understanding the nature of the world. He also thought that, in order to fully acquire the very Confucian, very legitimate way of searching for the philosophical truths of our lives(the so-called Gyeokmul-Chiji/ 格物致知 methodology), an accurate understanding of technological matters would be very crucial. That was why he argued the importance of reforming the national examination, which was rather focused upon testing the testees’ ability in the area of literary compositions alone, so that a subset of tests be included for the engineers or technological experts which could eventually pave the way for their enlistment inside the government and their flourish inside the entire society. His academical researches also show his technological interests, as primary subjects of his studies included carts, rocket launchers (火車), boats and water wheels(水車) etc. Another side of his studies features his interest in subjects like national history, national language and also the national territory. Shin Gyeong Jun was advancing his studies in the tradition of other researches of his time originated in the wake of heightened sense of pride for the country and caring for the people. These kinds of tendency were prevalent among the scholars in the capital area. He also inherited the previous historical and geological studies of Han Baek Gyeom and Yu Hyeong Weon, and established a new model for studies involving national subjects(the so-called Gukhak/國學 subjects) which would be prominently studied in the next era. His studies were not exclusive or dogmatic but a very magnanimous (in a very Hwaetong/會通 kind of way) one, embracing many important schools of thoughts, including not only the Buddhist and Taoist philosophies, but also 9 other schools of thoughts as well. Those 9 schools were the Yuga/儒家-Confucian, the Doga/道家-Taoist, the Eumyangga/陰陽家-Eum Yang theorist, the Beobga/法家-Judicial, the Myeongga/名家-Reputation, the Mukga/墨家-Philanthropist, the Jonghwaengga/縱橫家-Strategists, the Jabga/雜家-Miscellaneous, and the Nongga/農家-Agricultural. Shin Gyeong Jun’ s other junior colleagues, such as Damheon/湛軒 Hong Dae Yong/洪大容 or Yeonam/燕巖 Park Ji Weon/朴趾源, had the opportunity to visit the Chinese Ch’ ing dynasty as a member of the national envoy and experience the superior and advanced culture and technology of China. They also embraced the philologico-bibliographical studies of Ch’ ing. Yet Shin Gyeong Jun, although he wanted to join the Ch’ ing envoy, did not have the opportunity to do so or to study such new Chinese academical trends. The Chinese influence that can be traced from his works seems to have come from Western science and technologies which were introduced to the Chinese people through the actions of Western missionaries during the transitional period between the Ming and Ch’ ing dynasties. He was deeply interested in new pieces of technology such as Water wheels(which were deemed so in even China as well) and tried to adapt those technology to the Chosun terrain. Also, his suggestions

조선후기 開城의 도시구조와 상업

高東煥(Ko Dong Hwan) 역사문화학회 2009 지방사와 지방문화 Vol.12 No.1

본 연구는 農本體制하에 상업억제정책을 강하게 유지했던 조선왕조에서 왜 유독 개성지역에서만 末利를 드러내놓고 추구하는 상업을 영위할 수 있었는지를 개성의 도시구조와 개성상인들의 구체적인 상업활동을 통해 살펴본 것이다. 개성에서 상업이 용인된 까닭은 상인 중심으로 구성된 주민구성, 화폐경제를 기반으로 한 재정운영의 특성때문이었다. 토지와 家戶, 人丁에서 수취한 각종 賦稅를 기초로 운영된 대부분의 郡縣과 달리 개성은 상인에게 거둔 세금과 금전대부를 통한 이자수입을 재정의 기초로 삼지 않을 수 없었다. 상업이윤을 재정의 근본으로 삼았기 때문에, 조선사회의 강력한 억말정책하에서도 개성에서는 상업을 용인하고 권장하지 않을 수 없었던 것이다. 개성은 조선후기이후 영역의 확장, 인구의 급격한 증가를 나타내는 도시였다. 1796년(정조 20) 개성부는 금천군(소남면, 대남면)과 장단부(사천이서지역) 일부와 1823년(순조 23)에는 풍덕부 전체를 합병하였다. 개성의 인구추세를 보면, 15세기 중엽 8,372명이었지만, 1756년 34,285명, 1855년경에는 75,482명으로 증가하였다. 私商을 대표하는 개성상인의 상업활동은 매우 다양했다. 개성부내의 상설점포인 시전상업, 전국적 行商과 都賈商業, 중국과 일본을 대상으로 한 무역, 그리고 개성상인들 사이에서 행해진 금융활동과 인삼의 재배와 경작,나아가 홍삼의 제조와 유통에 이르기까지 개성상인들의 활동영역은 상업분야 외에도 농업과 금융, 제조업에까지 미쳤다. 개성상인들은 인삼유통권 장악을 기초로 중개무역에 참여하여 막대한 이익을 얻을 수 있었다. 개성상인들은 국내 상업과 국제무역에서 축적한 자본을 광업이나 삼포업에 투자하였다. 개성상인들의 자본규모는 1874년의 4개월동안 상품구입 총액은 10만 3,469냥에 달할 정도였다. The current study examined the reason why merchants were able to operate commercial activities pursuing profits only in Gaesung area during the Joseon Dynasty that had strong commerce restriction policies based on agriculture-based system through the structure of Gaesung and concrete commercial activities of merchants in Gaesung. The reason why commerce was allowed in Gaesung was because of its own characteristics such as residents who were mainly merchants and financial operation based on monetary economy. Differently from most Guns and Hyeons that were operated on the basis of various taxes collected from land, families and individuals, the bases of finance in Gaesung were mainly taxes collected from merchants and interest profits through loaning. Gaesung could not help allowing and recommending commerce even under strong commerce restriction policies of the Joseon Dynasty because its financial basis wascommercial profits. Gaesung presented the expansion of the territory and a dramatic increase in population after the latter half of the Joseon Dynasty. Gaesung-bu incorporated some of Geumcheon-gun(Sonam-myeon and Daenam-myeon) and Jangdan-bu(Sacheon and Iseo areas) in 1796 (the 20th year of King Jeongjo), and the entire Pungdeok-bu in 1823(the 23rd year of King Sunjo). Its population increased to 75,482 in 1855 from 8,372 in the middle of the 15th century and 34,285 in 1756. Commercial activities of merchants in Gaesung representing private merchants were very various. Their activities ranged from the commercial area to agricultural, financial and manufacturing businesses such as Sijeon trade, permanent stores in the territory of Gaesung-bu, nationwidepeddling and Dogo commerce, trade with China and Japan, financial activities among merchants in Gaesung, cultivation of Ginseng, and production and distribution of red Ginseng. Merchants in Gaesung were able to get enormous profits by participating in intermediary trade on the basis of the right of ginseng distribution. They also invested capital accumulated from domestic trade and overseas trade into the mining industry or the ginseng industry. With regard to their capital size, the total amount used to purchase goods for four months in 1874 was 103,469 copper nyang.

조선후기~한말 신용거래의 발달 : 於音과 換을 중심으로

고동환(Ko Dong-Hwan) 역사문화학회 2010 지방사와 지방문화 Vol.13 No.2

18세기 이후 개성상인을 중심으로 발행, 유통되었던 어음과 환은 19세기 이후 일반 상거래에 매우 보편적으로 사용되었다. 환규모는 대체로 200냥에서 1,500냥 사이였다. 환은 주로 대상인들 사이에 유통된 신용환표이지만, 어음은 중소상인과 소생산자 사이에 널리 유통되었다. 1901년에서 1905년사이에 발행된 하나의 어음에 기재된 액수는 1만냥에서 5만냥이었다. 어음, 환은 상거래 뿐만 아니라, 임금지출, 여행시 경비지출, 국제교역의 결제수단, 매관매직시의 지불수단, 조세상납 및 국가재정운용 등 일상생활의 금전거래 전 분야에 걸쳐 활용되고 있었다. 심지어 죄수들의 속전납부나 강탈한 재물의 보관수단으로도 활용되고 있었다. 어음과 환이라는 신용화폐 유통의 유통은 어음 할인이나, 이를 담보로 한 금전대출업무를 담당하는 어음교환소의 출현을 필연화한다. 이와 같은 기능을 담당한 곳은 六矣塵 役人廳이었다. 이곳에서는 어음의 교환, 할인, 담보대출 등, 비록 은행이라는 간판을 달지 않았지만, 은행의 업무를 실질적으로 수행하고 있었다. 이와 같은 어음의 할인, 교환에 종사하는 居間層도 당시 서울에는 수백명을 헤아릴 정도였다. 또한 개항이후 외국 돈을 교환해주는 환전객주도 출현하였다. 개항이후 달러나 마르크, 엔화에 대한 교환시세도 형성되고 있었으며, 이 교환시세는 수시로 변동하였다. Since the 18<SUP>th</SUP>century, promissory note and money order were issued and distributed mainly by traders of Kyesung, but were commonly used in normal trade since the 19<SUP>th</SUP>century. Generally money order ranged from 200 coins to 1500 coins. Money order was mainly distributed among big traders, but promissory note was widely used for small traders and small manufactures. From 1901 to 1905 a stated amount of the promissory note was issued from 10,000 coins to 50,000 coins. Promissory note and money order were widely used for every field of financial transactions of daily life including commerce, payroll, travel expenses, payment of international trade, payment of buying and selling the official position, tax payment and national financial management. Moreover, they were used as a means of the ransom for the prisoners and storing wealth for robbed property. The distribution of credit currency such as promissory notes and money orders must bring the inevitable emergence of house for exchange of promissory notes in charge of discount of promissory notes and cash loans secured against promissory notes. The place responsible for these functions was Yukuijeon Yeokincheong. Although it didn't have a sign of bank, they do actual bank's business such as exchange of notes, discount and secured loans. There were traders engaged in discount and exchange of notes who were about to count the hundreds in Seoul at that time. In addition, after the Opening of port, another exchange traders who exchange foreign money were emerged. Since the Opening of port, the exchange rates for the dollar, the Mark and the Yen ware also formed and the exchange rate was often changed.