중등학교 교과서의 농업·농촌 기능 분석 및 반영 방안

서우석,강대구,정진수,김절용,김재호,이윤조 한국농업교육학회 2007 농업교육과 인적자원개발 Vol.39 No.2

HSS STI-CMP적용을 위한이중 패드의 최적화

서용진,박성우,김철복,정소용,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

As the device geometry shrinks to the deep submicron region, chemical mechanical polishing(CMP) planarization become a more essential technique of advanced ULSI process. Also, CMP process was required for the global planarization of inter-metal dielectric(IMD), inter-level dielectric(ILD) layers and interconnections with free-defect. Especially, the complete global planarization of IMD, ILD and interconnections can be achieved only with the CMP process. However, as the IMD and ILD layer gets thinner, several problems were found in the CMP process. It does have various problems such as dishing effect, torn oxide defects and nitride residues in oxide. So, it leads to severe circuit failure, which affects yield. In this paper, we studied the characteristics of polishing pad, which can apply STI-CMP process for global planarization of multilevel interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was defected less than 2 on JR111 pad. Through the above result, we can select optimum polishing pad, so we can expect the improvement of throughput and device yield.

영역분류를 이용한 블록화 현상 감소 기법

서용수,김중곤,김우열 東西大學校 2000 동서논문집 Vol.6 No.-

본 논문에서는 DCT(Discrete Cosine Transform)를 기반으로 정지영상을 압축한 후 복원된 영상의 블록화 현상을 감소시키기 위한 방법을 제안하였다. 제안한 블록화 현상 감소기법은 BCT 계수의 특성에 따라 단순영역과 복잡영역으로 분류한 후 분류된 영역에 따라 서로 다른 양자화 테이블을 적용시켰다. 인간시각 특성상 블록화 현상이 잘 나타나는 평탄영역과 단순에지 영역은 저주파 영역의 양자화 요소값을 작게 하여 블록화 현상을 감소시키고, 복잡 영역에서는 블록화 현상이 눈에 잘 나타나지 않기 때문에 양자화 요소값을 증가시켜 비트발생률을 줄일 수 있도록 하였다. 제안한 블록화 현상 감소 기법의 타당성은 컴퓨터 모의실험을 통하여 확인하였다. In this paper, we proposed a method of reducing blocking effects in reconstructed image that was compressed on DCT(Discrete Cosine Transform). The proposed blocking effects reduction techniques use difference quantization table according to region classification such as simple and complex region. The regions are classified by the characteristics of DCT coefficient. In flat and simple edge region, where blocking effects are more visible, we use small valued quantization table to reduce blocking effects. For complex region, blocking effects are less visible, we use large valued quantization table to reduce generated bit rate. Computer simulation results show that blocking effects of proposed method is reduced that of conventional method.

초등학교 교육과정과 교과서에 농업·농촌의 기능 및 가치 반영 방안

서우석,강대구,정남용,김재호,이윤조 한국농업교육학회 2006 농업교육과 인적자원개발 Vol.38 No.4

이 연구는 농업ㆍ농촌의 기능과 가치를 재정립하고 이를 초등학교 교육과정 및 교과서에 반영시킬 수 있는 방안을 제시하는데 그 목적이 있었다. 이를 위하여 먼저 선행연구 고찰을 통하여 농업ㆍ농촌의 기능과 가치를 재개념화하고, 이를 토대로 내용 분석 틀을 개발하여 초등학교 교육과정 및 교과서를 분석 하고, 그 결과를 토대로 교육과정 및 교과서에 반영시키기 위한 방안을 제시하였다. 그 주요 결과는 다음과 같다. 첫째, 농업ㆍ농촌의 기능과 가치는 크게 자연환경적 기능(수자원 함양 기능, 환경정화 기능, 생태계 보전기능, 자연재해 방지 기능), 사회문화적 기능(전통문화 보전 기능, 정서의 순화 기능, 자연학습의장 제공 기능), 사회경제적 기능(농산물 공급 기능, 직업 기회 제공 기능, 국토의 균형발전 기능, 타 산업에의 기여 기능)으로 분류하였다. 둘째, 농업ㆍ농촌의 기능과 가치를 바탕으로 초등학교 교육과정 및 교과서를 분석한 결과, 전 학년에 걸쳐서 자연학습의 장 제공 기능과 전통문화 보전 기능이 높게 나타났고, 그 다음으로는 농산물 공급기능과 정서순화기능이 높게 나타났다. 반면에 수자원함양기능과 환경정화기능은 상대적으로 낮게 나타났다. 셋째, 내용분석을 토대로 교과의 성격을 고려하여 각 교과별로 농업ㆍ농촌의 기능과 가치를 반영시킬 수 있는 방안을 제시하였다. 마지막으로, 각 교과별로 농업ㆍ농촌의 기능과 가치 반영 방안을 체계적으로 이행하기 위한 행ㆍ재정적 지원 방안을 교육과정 개발 측면, 교과서 개발 측면, 교육과정 운영측면, 정책적 지원 측면으로 구분 하여 제시하였다. The purpose of the study is to suggest the strategies for incorporating the roles and values of agriculture & rural areas as a part of the national curriculum and elementary school textbooks. For this purpose, this study was conducted as follows; First, we reclassified the roles and values of agriculture & rural areas after critically reviewing literature: environmental conservation functions, socio-cultural functions and socio-economic functions. Second, based on the new classification, we develop a framework for analyzing the national curriculum and elementary school textbooks. The functions of rural areas as places for learning about nature and purifying emotion and the importance of agriculture in providing agricultural product were frequently presented but the functions of sustaining water resources and environmental purification were relatively less presented in the national curriculum and elementary school textbooks. Third, we suggested strategies for incorporating the roles and values of agriculture & rural areas in the national curriculum and elementary school textbook based on the analysis. Finally, we suggested necessary administrative and financial assistance to systematically and effectively implement the suggested strategies for developing a new curriculum and textbooks as well as implementing the curriculum.

CMP 공정의 재현성 확보를 위한 공정제어 범위의 결정

서용진,정소영,김철복,박성우,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

To achieve the ULSI goals of higher density and greater performance, STI(shallow trench isolation)-CMP(chemical mechanical polishing) process has been attracted. Recently, the direct STI-CMP process without the conventional complex reverse moat etch process has established by using slurry additive with the high selectivity between SiO2 and Si3N4 films for the purpose of process simplification and in-situ EPD(end point detection). However, STI-CMP process has various defects such as nitride residue, torn oxide and demage of silicon active region. Also, it was difficult to assure the suitable process margin in the STI-CMP process. To solve these problems, in this paper, we discussed to determine the control limit of process, which can entirely remove the oxide on nitride film from the most area of high density as reducing the damage of dense moat area and minimizing dishing effect in the large field area. We, also, evaluated the wafer-to-wafer thickness variation and the day-by-day reproducibility of STI-CMP process after repeatable tests.

반도체-원자 초격자의 광전자 특성

서용진,정소영,박성우 대불대학교 2002 論文集 Vol.8 No.1

Optoelectronic characteristics of the superlattice as a function of deposition temperature and annealing conditions have been studied. The nanocrystalline silicon/adsorbed oxygen superlattice formed by molecular beam epitaxy (MBE) system. Consequently, the experimental results of superlattice with multilayer Si-O structure showed the stable photoluminescence(PL) and good insulating behavior with high breakdown voltage. This is very useful promise for Si-based optoelectronic and quantum device as well as for the replacement of silicon-on-insulator(SOI) in ultra high speed and lower power CMOS devices in the future, and it can be readily integrated with silicon ULSI processing.

탄소섬유 적층혼성부재의 계면수 변화에 따른 축 압궤 특성

서현경,박준우,양용준,황우채,양인영 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

알루미늄과 CFRP는 대표적인 경량화 재료이다. 알루미늄 부재는 안정적인 소성 변형에 의해 에너지를 흡수하며, CFRP 부재는 비강성과 비강도가 우수하고 불안정한 취성파괴로 인해 에너지를 흡수한다. 이러한 각각 알루미늄과 CFRP 부재의 압궤 특성을 기초로 두 재 료의 결합에 의해 서로의 장점에 대한 시너지 효과를 얻기 위해 혼성구조부재를 제작하였다. 본 연구에서는 알루미늄 부재의 외측을 CFRP로 강화시킨 혼성구조부채를 제작하여 CFRP의 계면수 변화에 따른 축 방향 준정적 압궤실험을 행하여 사각 및 원형 단변 모형의 혼성구조부재의 압궤 특성을 조사하였다. 실험 결과 혼성구조부재는 내부의 알루미늄 부재의 연성 성질 때문에 CFRP 부재의 불안정한 취성 파괴를 보완하여 비교적 안정적인 압궤 모드를 보였다. 하지만 혼성구조부재는 계면수 변화에 대해 에너지 흡수성과 압궤 모드는 별다른 영향을 보이지 않았다. The aluminum or CFRP is representative of light-weight materials. The aluminum tubes absorb energy by stable plastic deformation and the CFRP tubes absorbs energy by unstable brittle failure with higher specific strength and stiffness. Based on the respective collapse characteristics of aluminum and CFRP tubes, the aluminum CFRP compound tubes were manufactured to get a synergy effect when the aluminum CFRP tubes were combined with the advantages of each tube. This paper is to investigate the collapse characteristics of square or circular shaped aluminum CFRP compound tubes subjected to quasi-static axial collapse tests which were conducted by changing the stacking conditions. Test results showed that the collapse of the aluminum CFRP compound tubes complemented unstable brittle failure of the CFRP tube due to the ductile characteristics of the inner aluminum tube. It turned out that interlaminar numbers of aluminum CFRP compound tubes have no influence on the energy absorption and collapse modes of the tubes.

관상동맥 누공에 의한 급성 심근 경색 1예

서유승,최재웅,송창섭,조용범,양진수,박준섭,정인수 대한내과학회 2003 대한내과학회지 Vol.65 No.2

관상동맥 동정맥루 기형은 매우 드문 질환으로 치료가 불필요한 경우가 대부분이나 coronary steal 현상으로 인해 증상이 발생하거나 합병증이 발생한 환자에 대해선 치료를 요한다. 최근에는 시술에 적합한 누공을 가진 선택된 환자군을 대상으로 카테터를 이용한 중재적 시술이 시행되어 수술적 치료와 유사한 결과를 얻고 있다. 저자들은 젊은 남자에서 관상동맥 동정맥루 기형과 동반된 급성 심근 경색증을 진단하여 비 수술적 방법인 카테타 코일 색전술로 성공적 치료 후 증상 및 심근 재관류에 호전을 보인 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. We report a case of coronary fistula between the left anterior descending and main pulmonary artery complicating acute non-Q wave myocardial infarction. A 27-year-old man visited emergency department because of severe chest pain lasting two hours. The electrocardiogram showed ST segment elevation in precordial leads V3~6. Cardiac enzymes were as follows;CK-MB:36.44 IU/L T-T:0.489 ng/mL, CPK:542 IU/L, and LDH:475 IU/L. The thallium-201 dipyridamole stress perfusion scan showed perfusion defect and reversed redistribution in the anteroseptal wall. The coronary angiogram revealed coronary artery fistula between the proximal left anterior descending artery and main pulmonary artery without significant stenoses of coronary arteries. The result of ergonovine test was negative. After micro-coil embolization to the coronary fistula, symptoms were improved. Follow-up thallium-201 scan showed normalized blood flow in the left anteroseptal wall.

FeCoB계 아몰퍼스 자성박막의 임피던스효과에 관한 연구

서강수,정승우,임재근,신용진 명지대학교 대학원 1997 대학원논문집 Vol.1 No.-

In this paper, we has studied frequency dependence of impedance of FeCoB amorphous magnetic films. First, we investigated optimal composition and sputtering conditions for fabrication of zero magnetostrictive amorphous magnetic films. (Fe_(1-x)Co_x)_79Si_2B_19 was selected as the basic composition and then, the films were fabricated with x=0.94 and 0.95 respectively by using sputtering method at high frequency. In order to relieve the internal pressure and derive the magneto-anisotropic. we annealed the films in about 150[Oe] of magnetic field and in the range(280℃, 300℃ and 320℃ respectively) of crystallization temperature(360℃). In addition, we annealed the films under non-magnetic field and near crystallization temperatures (283℃/30min, 400℃/30min and 400℃/1hr respectively) in order to decrease magnetoanisotropic. Then, we investigated magnetic properties including magneto-impedence and inductance. As the results, we found excellent magnetic characteristics and high impedence changing rate(4.52[%/Oe]) when we fabricated a sample under the condition that input power 400[W], Ar gas pressure 6.4[mTorr]. sputtering time 30[min] and annealing time 30[min] at 300[℃] in 150[Oe] magnetic field Especially, the impedence changing rate which was basic characteristic of Ml element was 4.52[%/Oe] for x=0.94. Moreover, the inductance values of the samples annealed at 400[℃/30min] were higher by 132[%] to 197[%] than those of the non-annealed samples. In addition, the quality factor Q was below 0.7 for all samples. Consequently, we find that the zero magnetostrictive amorphous magnetic film can be used as a magnetic sensor material.

광양만과 여수해만의 표층퇴적물에서 Nonylphenol의 오염에 관한 연구

조현서,김용옥,설순우,-- 한국환경과학회 2004 한국환경과학회지 Vol.13 No.6

This study was carried out to survey the pollution of nonvlphenol (NP) in surface sediments around Gwangyang bay and Yeosu sound. NP was suspected chemicals as endocrine disruption. Gwangyang bay is located on the mid south coast of Korea. It is a semi-closed bay which Yeosu petrochemical industrial complex, POSCO (Pohang Steel Company) and Gwangyang container harbor are there. The surface sediments were collected at 15 stations with gravity corer at October, 1999, February, May and August, 2000. Also, the stream and intertidal sediment were collected at 5 sites at August, 2000. Concentrations of NP in surface sediments were in the range of 6.89 to 202.70 ng/g dry wt.. Seasonal range (mean value) of NP is 13.98 to 30.48 (23.46) ng/g dry wt. at October, 10.35 to 54.91 (28.10) ng/g dry wt. at February, 29.05 to 202.70 (82.32) ng/g dry wt. at May and 6.98 to 83.40 (25.37) ng/g dry wt. at August. NP was seasonally fluctuated, and the highest mean value and range was detected at May, 2000. NP was highly distributed in the inner part of Gwangyang bay than Yeosu sound. Concentrations of NP in stream and intertidal sediments showed the highest value in downstream near Yeosu petrochemical industrial complex and Yondung stream. It suggests that the source of NP is industrial wastewater and municipal sewage.