키토산에 대한 Itaconic acid의 graft 공중합과 그 특성

한상문,윤충수,김용범 서울산업대학교 산업대학원 1999 大學院論文集 Vol.6 No.-

Chitosan was prepared from chitin which was abstracted from wasted crab shell. Then itaconic acid was graft-copolymerized onto chitosan using ceric ammonium nitrate(CAN) as a reaction initiator. To investigate the optimal grafting conditions, the influences of several factors on the grafting were studied, i.e., the concentrations of CAN and itaconic acid, the reaction temperature and time. And to find out its flocculation ability, the flocculation test was carried out with a metal plating factory waste water. The state of the graft-copolymer was identified through IR spectra checking. The optimal grafting conditions and flocculation results were shown to be: concentration of ceric ammonium nitrate is ??, reaction temperature is 40℃ and reaction time is 4hrs with 0.25M of the monomer(itaconic acid). Through flocculation tests using chitosan, grafted chitosan(CsIa) and cation, CODcr, metal ions removal rates were measured. The order of superiority is CsIa>Cs>Cation.

도시연구를 위한 학술·연구정보망의 활용

한상연 경희대학교 지역문제연구부 1996 지역개발연구 Vol.3 No.-

본 논문은 원격통신(telecommunication)을 이용하여 도시학(Urban Studies) 분야의 교육과 연구를 효과적·효율적으로 수행할 수 있는 여러 방법들을 인터넷(Internet), 민간상용망, 연구전산망(KREONet) 을 포함한 정보/통신망을 중심으로 살펴본다. 본 논문은 도시학에서 활용할 수 있는 사례를 중심으로 하여 도서관을 포함한 국내외 DB의 활용 방법을 검토하였으며 원격통신이 강의실에 미치는 영향도 간략히 제시하였다. 선진국, 특히 미국에 비해 국내에서 원격통신을 적극적으로 활용할 수 있는 여건은 매우 미비하나 도시연구 및 강의에 통신기술의 활용을 시작할 수 있는 여건은 충분히 조성되었기 때문에 이 부분에 관한 이해가 시급하다고 사료된다.

산업기술 정책환경 변화에 따른 대응전략

한상연,이유신 경희대학교 지역문제연구부 1997 지역개발연구 Vol.4 No.-

탐색 공간 변형을 적용한 그래프 분할 문제 해결 방안

성연중,한치근 慶熙大學校 1997 論文集 Vol.26 No.-

In this paper, we consider a graph partition problem, in which we partition the vertices of the graph into 2 parts and minimize the sum of costs of edges that connect two parts. We use Kernighan's heuristic method based on a local search method for solving the problem, In order to increase the possibility of finding the global optimum, we apply smoothing techniques to the heuristic method and propose two smoothing algorithms. Also, we propose an algorithm for obtaining an initial solution and using the initial solution, we can get a minimum solution that is not worse than solutions that can be obtained using many random initial solutions. Through the computational experiments, we demonstrate the proposed methods are better than the existing method for the graph partition problem.

침전법에 의한 CaCO₃:Sn^(2+) 형광체의 합성

한상목,신대용,윤봉구 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

침전법을 이용하여 CaCO₃를 합성한 후, 활성제로서 Sn^(2+)를 도핑하여 CaCO₃:Sn^(2+) 형광체를 합성하고 결정상과 형상 및 Sn^(2+) 첨가량에 따른 형광특성을 조사하였다. CaCl₂·2H₂O-(NH₄)₂CO₃수용액에 NH₄OH를 첨가하여 pH가 증가하면 입자의 응집이 관찰되지 않고 vaterite상이 장시간 안정하게 존재하였으며 pH 11에서는 1~3㎛의 순수한 구형 vaterite상이 얻어졌다. Vaterite인 구형 CaCO₃:Sn^(2+) 형광체와 열처리한 구형의 calcite형 CaCO₃:Sn^(2+) 형광체는 230 nm에서 최대로 여기되어 465 nm에서 최대 발광강도를 나타내었다. 합성된 CaCO₃:Sn^(2+) 형광체는 결정상과 관계없이 SnCl₂·2H₂O의 첨가량이 2 mol%일 때 가장 강한 발광강도를 나타내었으며, 능면체의 calcite형 CaCO₃:Sn^(2+)형광체는 열처리하여 안정화된 구형의 calcite CaCO₃:Sn^(2+) 형광체와 구형의 vaterite형 CaCO₃:Sn^(2+) 형광체에 비해 높은 발광강도를 나타내었다. Vaterite type of CaCO₃ was synthesized by using the precipitation method(CaCl₂-(NH₄)₂CO₃ system) with addition of NH₄OH at different temperature, time, pH and concentration. As a result, pure vaterite having spherical shape(0.1~10 ㎛ in size) was formed at the condition of high pH(>11) and high concentration(>5 M). CaCO₃:Sn^(2+) phosphors(spherical vaterite) were synthesized at CaCl₂-SnCl₂-(NH₄)₂CO₃-NH₄OH system. CaCO₃:Sn^(2+) phosphors(spherical vaterite) were transformed to CaCO₃:Sn^(2+) phosphors(spherical calcite) by heating at 550℃ for 10 min. The Particle sizes of CaCO₃:Sn^(2+) phosphors(rhombohedral calcite) and CaCO₃:Sn^(2+) phosphors (spherical vaterite) were 10~15 ㎛ and 1~3 ㎛ respectively. The excitation spectrum of CaCO₃:Sn^(2+) phosphors(spherical vaterite and spherical calcite) exhibited a maximum peak intensity at 230 nm with a narrow absorption band from 220 nm to 240 nm. At the excitation spectrum of 275nm, the emission spectrum of CaCO₃:Sn^(2+) phosphor (rhombohedral calcite) with SnCl₂of 2 mol% exhibited a maximum peak intensity at 465 nm of bright blue fluorescence. Also, the emission spectrum of CaCO₃:Sn^(2+) phosphors(spherical vaterite, spherical calcite) exhibited a maximum peak intensity at 465 nm but exhibited weak peak intensity than CaCO₃:Sn^(2+) phosphors(rhombohedral calcite).

2분할 2상 쵸퍼에 의한 태양광발전시스템에 관한 연구

한경희,성낙규,김연경 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

In this paper, two-phase chopper system with two separated groups to obtain two identical DC is used to charge the energy from the solar cell in two battery. They are controlled to be operated around maximum output of the solar cell under the condition of constant voltage. Photovoltaic system with DC-AC conversion is also investigated for big capacity and two separated electric power using two separated inverter.

테헤란로 高層事務所 建物 저층부의 公共空間에 관한 연구

윤한섭,김성홍 대한건축학회 2003 대한건축학회논문집 Vol.19 No.3

This paper discusses the public space of the high-rise office buildings on Teheranno street. Since the 1980s, there has been a rapid growth in the construction of high-rise buildings due to the development of architectural technology and the increase of land price along this street. The ground level of high-rise office building is the buffer space between private and public realm and its roles in urban space becomes considerable. Nine buildings between Samsung and Kangnam subway station were chosen and classified according to their site areas and their relationships to the adjacent streets. Three aspects were primarily analyzed and interpreted. 1) the ratio of the public space and site area, 2) the programs of the ground level, 3) the spatial accessibility and permeability between buildings and streets. The paper reports that the buildings generally meet the legal requirements, yet their functions as public space were limited, and argues the importance of the linkage between urban and architectural design.

삶의 질 향상을 위한 도시문화의 재발견

한상연,신영산 경희대학교 사회과학대학 1999 社會 科學 論叢 Vol.17 No.-

MALT 림프종을 수반한 쉐그렌 증후군

한원정,차상윤,김은경 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.2

Sj□gren's syndrome is a chronic inflammatory disease that predominantly affects salivary, lacrimal and other exocrine glands. We report a case of Sj□gren's syndrome combined with MALT (mucose associated lymphoid tissue) Iymphoma which occured in the parotid gland. A 57-year-old female with the complaint of painful swelling and iymph node enlargement was referred to our department. Sialograms of both parotid glands showed globular collections of contrast material uniformly distributed throughout the parotid gland. Salivary scintigraphy showed decreased uptake of the parotid gland. CT scan showed larger, slightly more dense parotid gland than normal and honeycomb glandular appearance. Also, It showed discrete, slightly more enhanced round mass in the left parotid gland. Histopathological finding showed replacement of salivary gland parenchyma with dense small lymphocytic infiltration having the feature of epimyoepithelial islands. Kappa light chain restriction of interglandular plasma cell could be seen. (Korean J Oral maxillofac Radiol 2000; 30: 144-148)

지방정부의 정보기술이용 활성화 방안 : 한국과 미국의 비교연구 A Comparative Study of Korea and the U.S.

한상연 경희대학교 사회과학대학 1998 社會 科學 論叢 Vol.16 No.-