베인 회전각의 변화에 따른 디퓨저의 성능특성에 관한 실험적 연구

조성국,강신형,Cho, Sung-Kook,Kang, Shin-Hyoung 한국유체기계학회 1999 한국유체기계학회 논문집 Vol.2 No.2

Recently, impressive gains of performance and efficiency with apparently little or no loss in flow range have been seen with the use of LSVD(Low Solidity Vaned Diffuser) over vaneless diffuser. Experiments of the effects of the vane turning angle variations(positive, negative, zero), with the other design parameters fixed, on the performance and flow range were carried out. Diffusers with a zero turning angle have the best characteristics in terms of performance and efficiency and the FFT results show different frequency characteristics due to vane turning angles in low flow range.

협업 세션 중심의 동기식 원격교육 시스템의 설계 및 구현

조성국,이장호,Cho, Sung-Goog,Lee, Jang-Ho 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.1

Most of the computer-based distance learning systems are asynchronous ones that allow students to download from the server the lecture previously given by a lecturer. While these asynchronous systems has the advantage that enable students to view the lecture with no time restriction, the study may not be effective due to the lack of support for real-time interaction between students and lecturers. Based on the student-lecturer-collaboration session model, this paper presents a collaboration session-centric synchronous distance learning system that supports real-time interaction between students and teachers, awareness information during lecture, and feedback from students. Basic feature of the proposed system include audio and video conferencing, text-based chat, and shared slide with annotation support. 컴퓨터 기반의 원격교육 시스템의 대부분은 학생이 강의자에 의해 이미 강의된 내용을 서버로부터 다운로드하여 보는 형태의 비동기식(asynchronous) 원격 교육 시스템이다. 이러한 비동기적인 시스템의 경우, 시간에 구애 받지 않고 강의 내용을 볼 수 있다는 장점이 있는 반면, 학생과 강의자간의 실시간 상호작용 등을 지원하지 않음으로 인하여 학습 효과가 떨어질 수 있다. 본 논문에서는 학생과 강의자 간의 협업 세션(collaboration session) 모델을 기반으로 하여, 학생과 강의자간의 실시간 상호작용, 강의 중의 인지 정보, 그리고 학생으로부터의 피드백을 지원하는 협업 세션 중심의 동기식 원격 교육 시스템(collaboration session-centric synchronous distance learning system)을 제안하였다. 제안된 시스템의 기본 기능에는 음성 및 화상 회의(audio and video conferencing), 텍스트 기반 채트, 주석(annotation)이 가능한 공유 슬라이드가 포함된다.

구속 스트레스에 대한 백서 타액선의 Apo Taq 발현

조성국,강수경,어규식,전양현,홍정표,Cho, Sung-Kuk,Kang, Soo-Kyung,Auh, Q-Schick,Chun, Yang-Hyun,Hong, Jung-Pyo 대한안면통증구강내과학회 2013 Journal of Oral Medicine and Pain Vol.38 No.4

On this study, we treated rats with restraint stress, and observed the changes with an optical microscope. Within the salivary gland tissue, we measured cell apoptosis cycle evaluation which show positive reaction on TUNEL assay, and compared within the groups. For this study, 18 rats were divided into 3 groups; 1) 2 rats of group I were selected as a normal control. 2) 2 rats of group II, as a experimental control were placed in the restraint cone for 2 hours 3) 14 rats of group III were placed in the restraint cone for 2 hours once a day. The rats were sacrificed immediately (group II, as a experimental control), 1, 2, 3, 4, 5, 6 and 7days after application of the stress and the both parotid glands were excised. The conclusions follow. 1. 5 days after giving an confining stress to the parotid gland of Rats, we can observe the hypotropy and pus and inflammation of Rat parotid gland acinar cells, and after 7 days, we can see a cell apoptosis. 2. Through the In situ DNA end labeling assay and TUNEL dye, on serous glands, benign tumor cell increased with statistically significant result after 5 days from confining stress. And the index shows maximum value on 7th days, which is same result with histological opinion. Therefore, our study shows that a cell apoptosis can be induced by restraint stress on salivary gland tissue, and we think more study should be accomplished about the cell signaling pathway in the future. 본 연구에서는 백서에 구속 스트레스를 통하여 정서적인 스트레스를 가한 후, 이하선 조직의 형태학적 변화 양상을 광학 현미경으로 관찰하였으며, 타액선 조직에서 세포자멸사의 평가는 TUNEL assay에 양성을 보이는 세포 수를 측정하여, 각 군별 차이를 비교하여 다음과 같은 결과를 얻었다. 1. 백서 이하선에서 구속 스트레스를 가한 후, 5일부터 타액선 선포의 위축 및 농염이 관찰되었으며, 7일부터 세포자멸사소견이 관찰되기 시작하였다. 2. In situ DNA end labelling assay를 통하여 TUNEL 염색을 시행한 결과, 타액선 장액선포에서 양성세포가 구속 스트레스에 대해 5일부터 통계학적으로 유의하게 증가하여 7일째에 가장 큰 지수를 보여 조직학적 소견과 일치하였다. 따라서 구속에 의한 스트레스 증가에 따라 생체 내 타액선조직에서 세포자멸사가 유도됨을 증명할 수 있었으며, 향후 유도 신호전달 기전에 관한 연구가 이루어져야 한다고 사료된다.

진동시험을 통한 강판콘크리트(SC) 전단벽의 저응력수준에서의 구조 감쇠비 규명

조성국,소기환,김두기,한상묵,Cho, Sung Gook,So, Gihwan,Kim, Doo Kie,Han, Sang Mook 대한토목학회 2015 대한토목학회논문집 Vol.35 No.2

SC (steel plate concrete)구조는 새로운 구조형식으로서 SC구조물의 내진설계에 적용할 수 있는 감쇠비의 규명이 필요하다. 이 연구에서는 실험적 방법을 통해 SC구조의 감쇠비를 분석하였다. 연구를 위하여 SC 전단벽 시편을 제작하고, 대형 진동대를 이용하여 진동시험을 수행하였다. 시험에서 계측한 가속도응답신호는 전달함수로 변환한 후 동적실험모드분석기법을 적용하여 분석하였다. 구조물의 감쇠비는 입력운동의 수준에 따라 달라질 수 있으며, 이 연구의 실험에서 적용한 입력운동의 수준은 시편의 항복강도의 절반보다 낮은 수준으로서 여기서 분석된 구조감쇠비는 약 4%정도이다. 이 연구결과를 고려하여 SC구조물의 운전기준지진에 대한 내진설계에는 4% 감쇠비를 적용할 수 있을 것으로 판단된다. Steel plate concrete (SC) structure has been developed as a new structural type. Rational damping value shall be determined for the seismic design of SC structure. This study evaluated damping ratio of SC structure through experiments. For the study, a SC shear wall specimen was constructed and dynamically tested on the shaking table. Acceleration time history responses measured from testing were converted to the transfer functions and analyzed by using experimental modal analysis technique. The structural damping ratio of the specimen was identified as 4% to critical. Considering the shaking table test was performed at the excitation level corresponding to the low stress level of the specimen, 4% could be suggested as a structural damping for design of SC structure for operating basis earthquake.

연구논문 - 무기 / 촉매 : SiO2 가 첨가된 SnO2 후막소자의 CH3CN 에 대한 감지특성

조성국,박창길,박은희,손종락 ( Sung Guk Cho,Chang Gil Park,Eun Hee Park,Jong Rack Sohn ) 한국공업화학회 1993 한국공업화학회 연구논문 초록집 Vol.1990 No.3

소형 원심압축기의 성능평가에 대한 실험적 연구

조성국,강신형,Cho, Sung-Kook,Kang, Shin-Hyoung 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.8

The performance database of small-sized centrifugal compressors is needed for the design of high performance machines and also for the verification of design tools and analysis software. An impeller is designed, manufactured and tested. The effects of several parameters on the evaluation of performance are investigated and the performance test of parallel diffuser is also carried out. The proper estimation of static pressure, total temperature and blockage at the impeller exit is important for performance evaluation. 4 method in cooperation with 3-D calculation is suggested. The measured performances are in a good agreement with the predicted results. However, there are some discrepancies in efficiency.

경피신경자극치료기(TENS)의 기능별 주파수에 따른 교근과 피개상피의 혈류변화에 관한 연구

조성국,어규식,전양현,홍정표,Cho, Sung-Guk,Auh, Q-Schick,Chun, Yang-Hyun,Hong, Jung-Pyo 대한안면통증구강내과학회 2009 Journal of Oral Medicine and Pain Vol.34 No.1

The following results were obtained, after experimenting on change of masseter muscle and bloodstream epithelium with Transcutaneous Electrical Nerve Stimulator(TENS), among 16 male adults. 1. According to applying TENS, it was observed that bloodstream in muscle increases at 1.5, 3.0 Hz. 2. According to applying TENS, it was observed that concentration of moving blood cells in muscle increase at 1.5, 3.0, 6.0 Hz. 3. According to applying TENS, it was observed that velocity of bloodstream in muscle increases only at 1.5 Hz 4. Through experiment, applying TENS at level of 6.0 and 10.0 Hz, all bloodstream, concentration of moving blood cells, and velocity of bloodstream increasing rates were lower in muscle compared to of them in overlying epithelium; and especially increasing bloodstream and its velocity were most frequent at 6.0 Hz, and bloodstream of 10.0 Hz. From the results above when a physical therapy of TENS is carried out the frequency of 1.5, 3.0 H is effective, and as the frequency increases it is disadvantageous to the muscle.

수소연료전지 자동차의 쿨링팬 구동용 고전압 영구자석형 동기모터의 최적화 설계

조성국(Seong-Kook Cho),김원석(Won-Seok Kim),정경훈(Kyung-Hun Jung),조경석(Kyung-Seok Cho),박창호(Chang-ho Park) 대한전기학회 2013 대한전기학회 학술대회 논문집 Vol.2013 No.7

보험사들의 부당한 공동행위에 대한 판례평석 - 대법원 2006.11.23선고 2004두8323판결

조성국(Cho Sung-Kuk) 중앙대학교 법학연구원 2006 法學論文集 Vol.30 No.2

  Ten domestic insurance companies decided to abolish some free “emergency services” from Jan. 1, 1998 and implemented the plan. Then they abolished five other free services one after the other and charged for them one after the other. Korea Fair Trade Commission(KFTC) investigated the matter and issued a cease and desist order and imposed surcharges on the companies. The companies brought the case before Seoul High Court, which rejected it. They appealed to the Supreme Court.<BR>  Sec. 19(5) of Monopoly Regulation and Fair Trade Act prescribes “where two or more enterprisers are committing any of the acts listed in each subparagraph of paragraph (1) which practically restrict competition in a particular business area, they shall be presumed to have committed an improper concerted act despite the absence of an express agreement to engage in such act.” This legislation was affected by conscious parallelism developed in the United States cases. Parallel acts in the United States are one element of circumstantial evidences which agreement can be inferred from. Those are about factual inference. However, Korean Supreme Court ruled Sec. 19(5) is about legal presumption. For it, KFTC should prove two points; parallel acts and anticompetitiveness. The Supreme Court ruled KFTC succeeded in proving them. The companies resorted to the Sec. 58 of the Monopoly Regulation and Fair Trade Act. According to it, “[t]his Act shall not apply to lawful acts of an enterprise or an trade association conducted in accordance with other Acts and subordinate statutes.” They argued they followed administrative guidances by the competent authorities. However, the Supreme Court did not accept the argument to the effect that the section should be read narrowly.<BR>  The ruling by Supreme Court is meaningful in that it clarified the meaning of the Sec. 19(5) and Sec. 58 and applied stringent standards to the cartel case.

통신규제당국의 조직 및 절차에 관한 연구

조성국(Sung Kuk Cho) 중앙법학회 2009 中央法學 Vol.11 No.1

The communications industry is one of the most important industries and is closely related to our daily lives. Its effective regulation is essential, but very difficult because it is very specialized and change every moment. In 2008, Korea Communications Commission(KCC) was established for the effective regulation of Korean communications industry, which consolidated the former Ministry of Information and Communication(MIC) and the Korean Broadcasting Commission(KBC). The KCC consists of five permanent commissioners including the chairman. Two commissioners have been appointed by the President and one of them has been inaugurated as the Chairman of the KCC. The Chairman`s position is of Minister-level. The other three members have been recommended by the National Assembly, one by the President`s party and the others by the opposition parties. The KCC is similar in the organization and procedures to the Federal Communications Commission of the United States(FCC), which is classified as an independent regulatory commission. However, the KCC is an agency belonging to the President unlike the FCC. The FCC does not belong to any of legislative, administrative or judicial branch and is even called `the Fourth Branch`. The KCC adopted an organization with a collegial body for independent, fair and neutral decision making. It needs to be noted that the KCC should be practically operated to the purport of commission system. Generally, commissions have an tendency to be operated inefficiently compared with single-headed agencies. Commissions do not need to make all decisions through deliberation by members. For ordinary matters, it is more efficient for an chairman or his or her subordinates to handle. For this, the KCC has the Secretariat composed of two offices and three bureaus. The quasi-legislative power is also very important because the details about communications regulation are difficult to be prescribed in advance. The rules made by delegation of laws have the legal force for firms and courts. Any person dissatisfied with the measures taken by the KCC can file an appeal and a lawsuit. However, the special procedures for those are not prescribed in the laws. The measures taken by quasi-judicial procedures are not suited for ordinary appeals and lawsuits. The measures in communications industry should be finalized early in order to eliminate the uncertainties in business.