rudder 곡판 절단선에 관한 연구

정형배,김재중,김찬석 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

This paper suggests a method about how to get the NC code of intersection curve of rudder free form surface automatically. Suggested method uses NURBS interpolation and intersection in order to get the data of cutting lines and converts them in AutoLISP format to visualize in AutoCAD. This method has been tested by application in real rudder and shown the reliable results.

Goldman's Algorithm을 이용한 비외상성 흉통 환자의 분석

조석진,유진현,김찬웅,어은경,정구영 대한응급의학회 1999 대한응급의학회지 Vol.10 No.4

Back ground : It is important to evaluate the patient presenting with non-traumatic chest pain in emergency department, and it is also difficult to classify appropriately. The purpose of this study is to predict probability of acute myocardial infarction(AMI) and assess the group for low probability of AMI that is target for observation-unit of chest pain in emergency department. Methods : A prospective, clinical study was performed from March 1998 to August 1998 at the department of emergency medicine, Ewha Womans University Mokdong hospital. We classified high-probability group and low-probability group of AMI according to Goldman's algorithm and then compared with the final diagnosis. Results : The study included 218 patients. 84 patients(39%) was the high-probability group and 134 patients(61%) was the low-probability group of AMI. As compared with final diagnosis, AMI was 47 patients(56%) among the high-probability group and 1 patient(0.7%) among the low-probability group. We observed sensitivity of 98%, specificity of 78% in predicting AMI. Conclusion : The classification according to Goldman's algorithm may be useful predictor of AMI and improve triage for emergency department patients with chest pain. It is also helpful for management of observation-unit of chest pain in emergency department.

협동적 웹기반 학습에서 학습자 평가항목 개발 및 수업유형에 따른 평가사례 분석

박찬정,현정석 한국컴퓨터교육학회 2004 컴퓨터교육학회 논문지 Vol.7 No.6

협동적 웹기반 학습이란 웹을 매개로 학생들이 동료 학생, 전문가, 교수, 지역사회 인사, 다른 기관의 연구원 등과 함께 학습을 하는 것이다. 본 논문은 점차 활성화되어 가고 있는 협동적 웹기반 학습에서 학습자들을 공정하고 공평하게 평가하기 위한 도구를 제안하는 것을 목표로 하고 있다. 결국, 공정한 평가를 통하여 협동적 웹기반 학습이 가상공간에서도 체계적으로 원활히 이루어질 수 있도록 유도하고자 한다. 본 논문에서는 우선 협동적 웹기반 학습이 이루어지기 위한 환경 및 수업 방식을 조사한다. 이를 위해 실제 교실 수업에서는 협동학습 시 어떤 방식으로 학습자들을 평가하는지 조사·분석하고 이를 바탕으로 하여 협동적 웹기반 학습을 위한 학습자 평가 항목을 개발한다. 또한 팀 구성방식과 수업유형을 고려하였을 때 제안한 평가항목 중에서 참여도 측면, 협동성 측면과 개별책무성에 대해 학습자들의 평가사례를 분석한다. Cooperative web-based learning is an teaching strategy in which small teams, each of students with different levels of ability, use a variety of learning activities to improve their understanding of a subject via the web. The objective of this paper is to propose new assessment items for evaluating students fairly in cooperative web-based learning. As a result, improved academic achievement, improved behavior and attendance, and increased self-confidence can be made in cooperative web-based learning due to the fair assessment. In this paper, the environment and instructional strategies for successful learning are firstly examined. In addition, the existing evaluation items in traditional classroom are also analyzed in order to develop new evaluation criteria in the web. Based on these analyzed items, we propose new evaluation items for cooperative web-based learning. In addition, the proposed items related to participant ratio, cooperability, and accountability are analyzed according to team organization styles and instructional models.

人蔘이 自然發生高血壓쥐에 있어서 血壓 및 血漿 Renin 活性度에 미치는 影響에 關한 實驗的 硏究

孫宜錫,朴陞哲,許鳳烈,李禎均,林憲吉,咸駿洙,梁忠模,韓哲洙,朴贊雄,金海中 대한의학협회 1979 대한의학협회지 Vol.22 No.9

생산시스템과 생산전략유형의 적합성 : 개념적 모형 A Concepual Model

林錫賢,鄭燦鎔 釜山 大學校 經營 經濟 硏究所 1994 經營 經濟 硏究 Vol.13 No.1

생산전략과 생산시스템 사이에는 일정한 연계가 있으며 양자간의 적합여부는 기업성과에 큰 영향을 미치는 것으로 생각되고 있다. 이 논문에서는 몇 가지 전략변수를 매개로 하 하여 생산시스템과 생산전략의 적합관계를 결정하는 상황론적 통합모델을 구성하였다. 이를 위하여 생산시스템은 공정유연성과 제품집중성, 생산전략은 제품수량, 제품다양성, 혁신성을 기준으로 하여 각각 여섯 가지로 분류하였다. 이와 같은 적합성모델은 생산시스템과 생산전략의 대응관계가 기업성과에 미치는 영향을 알아보기 위한 실증연구의 개념적 틀을 제공할 수 있을 것이다.

3次元 空間 電流座標에 의한 電力分析과 能動電力필터의 性能評價用 시뮬레이터 開發

나석환,최찬학,정영국,정화균 여수대학교 1993 論文集 Vol.7 No.-

The definition of traditional 2-DS power factor current and co-ordinate did not represent clearly relation to power facter in circuit with nonlinear thyristor loads. A new simulator for performance evaluation of Active Power Filter (APF) by 3-D space current co-ordinate applicale to general power system have not been developed, because reserchers were merely interested in improvement of source current waveforms by using APF or its simulator. Moreover, There was not APF simulator with power analysis capability which was developed for the better. Current was decomposed by active, reactive, distortion, by digital correlation signal proccessing techique based on Nowomiejski theory. Therefore, A new 3-D space current co-ordinate composited by 3 current components was defined in this paper. A new 3-D space current co-ordinate was shown state and location of current vector by trajectories with 3-D co-ordinate rotation. It evidently has excellent performance not only performsance evaluation method of APF but alse evaluation method of general power system, not conventional domain but other domain. By proposed 3-D soace co-ordinate, space power factor is derived, the true state of physical meaning is proved, new distortion factor was proposed, this study was proved true state of appropriation throughout development of simulator for APF performance evaluation with power analysis capability.

Pd 촉매 하에서 알릴 디올의 아릴화 연구 : 방향족 히드록시 케톤 및 페닐 치환된 알릴디올의 합성 Highly Selective Synthesis of Phenyl-Substituted Allylic Diols

강석구,정경윤,박찬희,남궁은영,김태현 성균관대학교 기초과학연구소 1995 論文集 Vol.46 No.2

The coupling reaction of iodobenzene with allylic diols in the presence of Pd(OAc)_2 and nBu_3P as catalysts using K_2CO_3 as base afforded the phenyl-substituted allylic diols. However, under the same reaction conditions with Et3N as base, phenyl-substituted α-hydroxy ketone was obtained.

Silent Discharge와 TiO₂광촉매 산화반응을 이용한 VOCs 처리

박석출,정창훈,서정민,최금찬 동아대학교 환경문제연구소 1999 硏究報告 Vol.22 No.2

This study has been carried out for evaluation of VOCs treatment let out at the industrial field using a silent discharge process through process approvement and TiO₂ photocatalytic oxidation. And it was presented experimental results on the silent discharge plasma and TiO₂ photocatalytic oxidation processes at atmospheric pressure gas streams containing diluted concentrations of benzene, toluene, and xylene out of VOCs. It has shown that each concentration, background gas, flowrate, and applied power have effected on three materials decomposition and byproduct distribution. Analyses of benzene, toluene, xylene and byproduct concentration was carried out by GC-FID.

인공 황산비 및 질산비가 애기장대의 생장과 종자발아에 미치는 영향

이석찬,박정안,박종범 한국환경과학회 2003 한국환경과학회지 Vol.12 No.6

The experiment was carried out to investigate the effects of sulfuric acid and nitric acid among the main components of simulated acid rain (SAR) on the growth of vegetative organs and seed germination of Arabidopsis thaliana. The Arabidopsis treated with SAR supplemented with sulfuric and nitric acids, respectively, showed 28% and 30% decrease of shoot and root growth compared to the control plants, and also many necrotic spots on leaf surfaces after SAR treatment were observed. The shoot and root length for plants grown with nitric acid rain was 14% and 17% lower, respectively, compared to the control, whereas those grown with sulfuric acid rain was 24% and 25% lower than control plants. When Arabidopsis seeds were sown in distilled water, germination rate was 100% after 7 days. However, 80% in SAR medium supplemented with sulfuric and nitric acids, 88% in sulfuric acid rain medium and 93% in nitric acid rain medium. The germination abilities of seeds harvested from SAR supplemented with sulfuric and nitric acids, sulfuric acid rain, and nitric acid rain were 73%, 73% and 94%, respectively. Consequently, sulfuric acids showed more inhibitory effects than nitric acids on the growth of vegetative organs as well as germination rates in Arabidopsis.

플라즈마를 이용한 VOCs 중 트리클로로에틸렌의 처리에 관한 연구

이일락,박석출,서정민,조정구,최금찬 동아대학교 환경문제연구소 1998 硏究報告 Vol.21 No.2

This study has carried out for evaluation of Trichloroethylene treatment let out at the working place using a silent discharge, one out of methods to control Volatile Organic Compounds. 1. Comparative test for Ozone creation as a function of whether Trichloroethylene included or not, both of them were increased by 270ppm when the electric field intensity goes up(~30kV/cm) and dry air condition included Trichloroethylene were high more or less. It is expected that Trichloroethylene has an influence on Ozone creation as Ozone presecution substance. 2. Input Trichloroethylene concentration and flow rate related to electric field intensity had effect on decomposition efficiency. Trichloroethylene decomposition efficiency increased with rising of applied voltage. But, Treatment efficiency were lower than N₂ condition, in case of using dry air as diluted gas, due to dissipation of electron energy by triplet oxygen molecules. 3. The more increased concentration(100, 200 and 300ppm1, the lower decreased removal efficiency(96, 93.6, 90.3% at N₂ and 86, 84, 90% at dry air) and these tendencies were released at the flow rate(1, 2 and 3 ℓ / min) similarly. 4. Byproducts generated by oxidation of Trichloroethylene-Carbon monooxide, Ozone, Methyl Chloride, Chlorofom, l,l,l-Trichloroethane and Tetrachloroethylene were found out.