3D printable bioink using catechol-conjugated chitosan

이대헌,이해신 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

With the development of three-dimensional printing (3d printing) technology, the combination of this technique and biomedical approaches, such as biomaterial, tissue engineering. The most important part of 3d bioprinting is the bioink, the main material for printing. To allowing contain living cells or cultivates cells directly on bioink, it requires biocompatibility and cytotoxicity. In this study, we present a bioink, which has good processability. This bioink can transform into hydrogel spontaneously in physiological aqueous condition without any additional gelation process. Moreover, it is able to keep the printed shapes stably after direct writing in normal cell culture media. Proposing bioink is based on a chitosan, a natural polymer. The chitosan was mainly used as scaffold for tissue engineering and wound healing in biomaterial field.

베르사이유에서 베르사이유까지

이대헌 한국독일사학회 2003 독일연구 Vol.- No.5

1933년 이전 독일의 ‘사회화’ 문제와 석탄광산업

이대헌 한국독일사학회 2006 독일연구 Vol.- No.12

The ‘Socialization’ and Coal Mining Industry in Germany before 1933Dae-Heon LeeThe question of ‘socialization’ (Sozialisierung) or ‘nationalization’ (Verstaatlichung) of some industrial sectors in Germany took on various aspects according to the times. The key question in tho se times was how much the state should intervene in the social pro blems. The group, which played the most important role in the early de bates on the nationalization of the industry, was the Conservatives. Their assertion of the nationalization had two intentions: strengthening the State and checking the growth of the SPD. The coal mining industry became the key sector in the debates o n the socialization since 1880s, and after the great strike of th e coal mining workers in the Ruhr in 1889 this question was discussed in the Prussian State Cabinet. The SPD did not demand the nationalization of the coal mining industry until about 1900, and then made it its main parole. The conceptions of the postwar economic order, which we re drawn up during the First World War by the SPD and the famous industrialist Walther Rathenau, had al stressed the interventi on of the state in the economy. After the German Revolution in 1918 many social groups approved the socialization, and the debates on it peaked in the socialization movement. But the participants in the debates to k diferent views on the time and the sector for its realization. Therefore 193년 이전 독일의 ‘사회화’ 문제와 석탄광산업 153the socialization in Germany did not come off. Although the socialization of the important industrial sectors appeared in t he last phase of Weimar Germany once more, it remained also stil at a discussion stage.The socialization or nationalization of the key industrial sect ors had mainly appeared when the social and economic situation was very dificult. Although the SPD advocated the socialization undoubt edly, it 독일에서 국유화 내지 사회화에 관한 논의는 19세기 중엽의 사회문제에서 비롯되었으며, 초기에 가장 중요한 주창자는 보수주의자들이었다. 보수주의자들의 국유화론은 국가주의의 측면에서 국유화를 옹호했다는 점에서, 그리고 사회문제의 해결을 통하여 사회민주당의 성장을 저지하려 했다는 점에서 이중적인 목적을 지녔다. 사회민주당은 강령에서 사회화를 주장하긴 했으나, 특정산업, 특히 석탄광산업의 사회화를 주장한 것은 20세기 초였다. 또한 제1차 세계대전 중에는 사회민주당뿐만 아니라 저명한 기업가인 발터 라테나우도 사회화와 유사한 공동체 경제를 주장했다. 1918/19년의 혁명기에는 사회화를 어떻게 실행할 것인가를 두고 많은 논의를 거쳤으나, 바이마르 말기까지 논의의 수준을 벗어나지 못했다. 사회화 내지 국유화 문제는 대개 정치적 사회적 경제적 상황이 어려울 때 등장하였다. 그리고 이 문제에 관한 논의에서 사회민주당이 확고부동한 사회화의 지지자이긴 했지만, 논의 자체는 그들의 전유물이 아니었다. 많은 보수주의자들과 자유주의자들도 국유화 내지 사회화를 옹호하거나 혹은 사회민주당 다수가 주장하는 사회화 내지 국유화는 보수주의자들이 주장하는 국가개입의 강화와 결정적인 차이를 보여주기 어려웠다.

쟁점과 동향 : 식민지,점령지의 "협력"(Collaboration) 연구 ; 제2차 세계대전 당시 독일 점령지에서 "collaborator"의 등장에 관한 연구: 프랑스, 네덜란드, 헝가리의 경우

이대헌 역사학연구회 ( 구 고대사학회 ) 2005 사총 Vol.61 No.-

내장형 시스템을 위한 재목적 링킹 로더

李大憲,禹德均,表昌祐 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

In a development environment for embedded system with a connection between host and target system, the linking loader of host system links the cross-compiled object file and a modules of target system and downloads the linked object file to the target system. In this research, we separate this linking loader into the module dependent on object file format and the module independent on object file format. The dependent module gets the linking information independent of file format from the object file, and the independent module actually does the linking process with this linking information. We implemented the dependent module by using BFD library of GNU development environment, and this implementation can improve the portability of our linking loader for a new target system or object file format. Currently, we developed this linking loader in the embedded system development environment ESTO to be prepared for a commercial product.

독일 루어광산업에서의 노동시장의 발전과 노동시장 당사자들의 대응(1900~1933)

이대헌 전남사학회 2003 역사학연구 Vol.20 No.-

This article outlines the development of the labor market in the Ruhr coal mining area from the late 1890s to the early 1930s years, analyses the measures of the parties concerned(industrialists and workers or trade unions), and estimates the efficiency of their actions. The Ruhr coal mining area had suffered from labor shortage before 1924 when it began to experience labor redundancy. The responses of the parties concerned to the fluctuation of the labor market were very various. In the time of the labor shortage the employers in the Ruhr coal mining tried to mobilize and keep the workers in their working place by providing incentives. For example, before 1914 the industrialists introduced the company welfare schemes including the housing program for workers. But the plan of the industrialists brought out a little or no result, because the mining workers increasingly were not reluctant to leave the working place for the others. In the period of the World War(1914~1918) and the post-war-years from 1919 to 1923 the mining labor market was subject to fundamental change with the alternation of the economy between war time and peace time. As the labor shortage continued the state intervention and the institutionalization of labor market system tended to be reinforced. The French and Belgian occupation of the Ruhr coal mining area from January to September 1923 marked a turning point in the Ruhr labor market. When the ?passiver Widerstand? ended, the financial situation of the coal mining companies in the Ruhr was the worst and their products were dull of sale. In order to overcome the crisis in coal mining industry the industrialists in the Ruhr attempted to rationalize the mining industry. The measures of industrial rationalization in the Ruhr coal mining industry included shutdown in full or in part and modernization or replacement of the old facilities. The consequences of the rationalization were mass layoffs of miners. Therefore it can be said that the rationalization of the Ruhr coal mining companies not only meant an active management policy but also a very effective labor market policy. Now the employers had a free hand to decide who would be redundant or not. Inevitably it intensified the conflicts between the employees and employers in Ruhr particularly in the time of the world-wide economic recession from 1930 to 1933. In sum, the change of labor market in the Ruhr coal mining industry since 1924 contributed to transfer power and influence to entrepreneurs in the Ruhr.

폴란드의 나치과거 청산: ‘8월 포고령’과 ‘중앙위원회’의 활동을 중심으로

이대헌 호남사학회 2007 역사학연구 Vol.29 No.-

Coming to Terms with the NS-Past in Poland by ‘August Decree’ and Main Commission This article explored the coming to terms with the past in the German-occupied Poland during the communist regime (1944~1989). The first attempts to document German war crimes were undertaken as early as end 1939, but the ‘August Decree’ was one of the first acts of legislation to be issued by the ‘Polish Committee of National Liberation’(PCNL). This ‘Decree’, still in force today, stipulated the punishment for Nazi criminals guilty of killing and torturing civilians and POWs, as well as of traitors of the Polish Nation. The task of documenting war crimes was entrusted to the ‘Commission for the Investigation of German Crimes in Poland’, created in October 1944 by PCNL and called the ‘Main Commission’. The task of Main Commission was to investigate German Crimes committed against Polish citizens during the wartime. The Main Commission cooperated with its several national and international partners and provided legal assistance to foreign courts and public prosecutors. After the fall of communist regime in Poland the Main Commission could be able to prosecute crimes committed by Soviet and Polish Regimes, that ist, Stalinist crimes before 1956 and crimes against humanity before 1989. The Institute for National Remembrance, established 1998, included the activities of Main Commission. Main Commission is a good example of coming to terms with the past: its international cooperations, systematic collections of documents, publication of materials, and organizational research. 폴란드의 나치과거 청산: ‘8월 포고령’과 ‘중앙위원회’의 활동을 중심으로 폴란드에서 나치의 전쟁/점령범죄에 대한 처리는 이미 전쟁 직후에 시작되었으나, 처벌은 1944년의 ‘8월 포고령’과 1945년 ‘중앙위원회’의 설치로 본격화되었다. 폴란드에서 자행된 나치독일의 전쟁/점령범죄 처벌에 제도적 기반을 제공한 ‘8월 포고령’은 이후 몇 차례의 개정을 거쳐 현재까지도 유효하다. 또한 ‘중앙위원회’는 전쟁/점령범죄 행위와 관련된 자료의 조사와 수집, 그와 관련된 국내외 조사결과의 출판 및 외국의 유사기관과의 협력 등을 과제로 설정했다. ‘중앙위원회’는 ‘지역위원회’, ‘최고민족재판소’, ‘유엔전쟁범죄위원회’, ‘폴란드군조사단’ 등 여러 파트너들과 협력하여 현재까지 약 20,000명 정도의 전쟁범죄 관련자들을 처벌할 수 있는 근거자료를 제공했다. ‘중앙위원회’는 1950년에 연구기관으로 전환되었다가 1950년대 후반 독일에서 ‘규명센터’의 설치를 계기로 다시 본연의 활동을 개시했다. 그리고 1970년대 초 서독과 폴란드 사이에 외교관계가 열리면서 나치범죄의 추적을 위한 양국의 협력관계는 더욱 긴밀해졌다. ‘중앙위원회’는 1989/90년의 체제전환과 더불어 활동의 중심을 스탈린주의적인 범죄로까지 확대했고, 1998년에는 ‘민족기억연구소’의 한 부서로 현재까지 활동하고 있다. 폴란드의 과거사 정리는 처음부터 국내외 관련기관과의 긴밀한 공조 위에서 진행되었고, 냉전으로부터 강한 영향을 받았으며, 제도적인 기반 위에서 실행되었다. 폴란드의 과거사 정리는 자료의 철저한 수집과 정리, 관련기관과의 긴밀한 협조, 자료의 출판, 대중교육, 그리고 조직적이고 체계적인 연구 등으로 이어졌다. 이는 과거사 정리의 모범적인 사례에 속한다.

1P-243 Mussel-inspired adhesive bioink for 3D-printing

이대헌,이해신 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Marine mussel, can adhere to almost all types of surfaces even if under the wet condition, uses mussel foot protein for attach on the surface. Mussel foot protein is mainly composed of L-3, 4-dihydroxyphenylalanine (DOPA) and lysine. We developed a catechol-conjugated chitosan (Chi-C) for mimicking the chemical structure of the adhesive proteins. Chi-C can be a hydrogel form spontaneously. However, Chi-C has low modulus to maintain its structure in early stage. In this work, we demonstrated vanadium ion added Chi-C to apply bioink for 3D-printing system. In case of Chi-C, it takes over 3 hours to become solid-like state. Whereas, Vanadium added Chi-C (V-Chi-C) takes under 0.5 hour. Moreover, Chi-C shows poor shape fidelity due to low modulus. The trace amount of vanadium supports gelation of Chi-C. In conclusion, the enhanced modulus of the V-Chi-C provided good shape fidelity. Small amount vanadium could be allow for faster gelation of Chi-C.

19세기 말 20세기 초 독일 루어지역 광산업에서 <노동자 위원회>의 도입을 둘러싼 논의

이대헌 한국서양사학회 2004 西洋史論 Vol.0 No.80

This paper intends to examine the institutionalization of the workers committee in German mining industry. The first attempt to institutionalize the industrial conflicts had something to do with the great strike of the Ruhr mining workers in 1889. The miner strike of 1905 was the most important moment to force the obligatory establishment of the workers committee. But in the frist election for the workers committees in 1905 did the absolute majority of the Ruhr miners abstain in order to protest against the unreasonable provisions of the mining law. Most studies about the workers committees had taken the abstention as the propaganda of the social democratic "alter Verband". But this paper had come to the conclusion that there was a close relation between the abstention and the organizational endeavors of trade unions. The prussian government intended to check the growth of labor movement by establishing the workers committee system. But the coal mining industrialists would be willing to make no concession at all to the workers committee; the trade unions would like to use it for their organizations. Neither workers nor employers had trusted each other. The workers committees in the mining industry were established to substitute this mistrust by the mutual regulation trust. But in this early phase they could neither function well nor contribute to the solution of conflicts in work places because of the legal flaws.

키보드 누설 방사에 의한 정보 누설 취약성 분석

이대헌,황인호,Lee, Dae-Heon,Hwang, In-Ho 한국전자파학회 2007 한국전자파학회논문지 Vol.18 No.1

본 논문에서는 PC 키보드의 누설 전자파에 의한 정보 누설 취약성을 분석하였다. 먼저 키보드 프로토콜과 하드웨어 구조를 살펴보고, 키보드에서 PC 본체로 전송되는 데이터 신호와 본체 전원선에 누설된 신호 사이의 상호 관계를 분석함으로써 키보드 전도성 방사의 원인을 파악하였다. 또한 키보드 누설 전자파의 크기를 계산하고 CTSPR 22 규격의 허용 레벨과 비교하였다. 간단한 실험을 통하여 PC본체 전원선의 신호를 분석하여 키보드 글쇠 내용을 얻을 수 있음을 보임으로써, PC 사용자의 중요 정보가 누설될 수 있음을 확인하였다. In this paper, we analyzed the vulnerability of information leakage due to the leakage electromagnetic waves of a PC keyboard. First, we reviewed the keyboard protocol and hardware structure, we analyzed the correlation between the data signal, which is transmitted from the keyboard to the main body, and the leakage signal on the power cable. With the result, we grasped the cause of the Conducted Emission of a PC keyboard. Also, we compared the limit level of the CISPR 22 standard with the amplitude of the keyboard leakage electromagnetic waves we calculated. By analyzing the signal on the power cable of the PC main body through the simple experiment, we show that it is possible to extract the contents of the PC key. Therefore it is verified that the secret information of the PC user could leak out.