표본화 및 유지회로 성능향상에 관한 연구

홍국태,이성대,정강민 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.1

In this paper, a high speed, high accuracy sample and hold circuit that minimizes the hold step error by using a new circuit architecture is proposed. This new sample-and-hold scheme takes advantages of the speed of the open loop sample-and-hold circuit in the SAMPLE time and the cancellation of charge injection in the HOLD time. It operates above 50MHz with 0.3mV hold step error.

高周波 通信用 FIR Digital 필터의 設計

洪國泰,李成大,鄭康敏 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.2

In this paper, a programmable high-sample-rate FIR digital filter was designed for a highbandwidth communication system. A fully parallel bit-level pipelined transpose-form carrysave architecture using CSD coefficients was adopted for high-speed operation. In this system, multiplication can be translated to simple shift-addition processes. For programmability of filter coefficients, two decoders and a few registers are added, and the shifting processes of input data are controlled according to the data registered. Therefore, the speed performance of the designed filter is comparable to the case of a non- programmable filter.

Haloperidol이 수면에 미치는 영향

왕성근,김상국 대한생물치료정신의학회 1998 생물치료정신의학 Vol.4 No.1

요 약 항정신병약물인 haloperidol이 수면에 미치는 영향을 파악하기위하여, 20-25세 사이의 소위 건강한 남자 대학생 7명을 대상으로 다원수면기록을 실시하여 분석한 결과를 요약하면 다음과 같다. 1. Haloperidol은 총수면시간에 대한 1단계 수면양을 감소시키고, 서파 수면을 증가시키는 효과가 있었다. 2. haloperidol은 수면 효율을 증가시키는 효과가 있었다. 3. 일반적으로 2단계 수면의 양은 1단계 수면 및 도중 각성과, 주간 졸리움은 서파수면의 양과 역상관관 계에 있었다. 4. haloperidol 투여시 총수면시간은 서파 수면의 양, REM 수면의 양, 및 주간 졸리움과 역상관관계에 있었다. To investigate the effects of haolperidol on sleep and subjective daytime sleepiness, authors applied polysomnography for sleep structure and visual analogue scale for daytime sleepiness to normal volunteers. The subjects were 7 healthy young adults, aged from 20 to 25 years old. The results were summarized as follows. 1. The effects haloperidol on sleep structure in normal adults were decreasing the amount of stage 1 sleep, increasing slow wave sleep(SWS), and increasing sleep efficiency. 2. In general, relative amounts of stage 2 sleep correlated with the amount of stage 1 sleep and WASO negatively, and daytime sleepiness correlates with the amounts of SWS negatively. 4. After administration of haloperidol, total sleep time correlates with the amounts of SWS and REM sleep, and daytime sleepiness negatively.

습기제거시스템의 성능에 관한 연구

유성연,정민호,홍정표,심국진,김광영 忠南大學校 産業技術硏究所 1997 산업기술연구논문집 Vol.12 No.2

The performance of moisture removal system is investigated analytically and experimentally. The program for the moist air calculation and for the condensing tube design are developed to examine the factors which affect moisture removal rate. Experimental apparatus comprises condensing tube, cooling system, vacuum pump, measurement and control devices. Thermoelectric cooling system and vapor compression refrigeration system are used to cool the air, and the performance of two systems are compared each other. Thermoelectric cooling system is compact and free from noise and vibration, but cooling rate of it is relatively slow compared to that of vapor compression refrigeration system. Air velocity, indoor temperature and humidity, temperature of coolant, size and material of condensing tube are found to affect the performance of moisture removal.

삼각측량 시스템을 이용한 3-D 형상 복원

홍성표,김국세,한승조,김길준,김충원,이준 조선대학교 전자정보통신연구소 2001 電子情報通信硏究所論文誌 Vol.4 No.2

The 3-D shape use to effect of movie, animation, industrial design, medical treatment service, education, engineering etc... But it is not easy to make 3-D shape from the information of 2-D image. There are two methods in restoring 3-D video image through 2-D image; First the method of using a laser; Second, the method of acquiring 3-D image through stereo vision. Instead of doing two methods with many difficulties, I study the method of simple 3-D image in this research paper. We present here a simple and efficient method, called direct calibration, which does not require any equations at all. The direct calibration procedure builds a lookup table(LUT) image and 3-D coordinates by a real 3-D triangulation system. The LUT is built by measuring the image coordinates of a grid of known 3-D points, and recording both image and world coordinates for each point; the depth values of all other visible points are obtained by interpolation.

효과적인 하중운반체계의 동역학적 연구

서국웅,양점홍,윤양진,황영성,이중숙,김용재,유경복 釜山大學校 附設 體育科學硏究所 1994 體育科學硏究所 論文集 Vol.10 No.-

The purpose of this study was to get the quantitative data of effect of two different load carrying system on Kinematics and Kinetics. The subjects for the research were 2-adults. The mechanism of each load carrying pattern was measured by a motion analylizer, a forceplatform and EMG system. The conclusions were get from Kinematics variables and Kinetics variables. 1. It was not effected at the vertical reaction force(Fz) of left, right foot according to the big value the 1st peack of 10kg, 15kg fore, back-pack carrying system, 20 kgw, 30 kgw back-pack carrying system in walking. But it was effected at the vertical reaction force(Fz) on 30 kgw back-pack carrying system in walking. 2. It was not effected at the Anterior-Posterior reaction force(Fx) of left, right foot according to high value of the 1st peack on 10 kgw, 15 kgw fore, back-pack carrying in walking. But, it was effected on the 20 kgw, 30 kgw only back-pack carrying in walking. 3. It was effected at the left-right reaction force(Fy) of left-right foot according to the big value of the 2nd peak on 10 kgw, 15 kgw fore-backpack carrying system in walking. It was more effective than 20 kgw, 30 kgw back-pack carrying system in walking. There was not disorder force(Fx) on 10 kgw, 15 kgw fore-backpack carrying system in walking. 4. Analysis of computer graphic, on the pack carrying system in walking. It was efficient in 10 kgw, 15 kgw fore-backpack carrying system in walking. But, it was efficient on 20 kgw, 30 kgw backpack carrying in walking. Castrocnemius, Tibialis anterior, Vastus lateralis, Vastus medialis, are stressed to bend their body foreward. So it occurred fatigue fast, injured muscles and joints. 5. Extension anyles and flection angles of the knee joint and the hip joint on 10 kgw, 15 kgw fore-backpack carrying system in walking showed less than those on 20 kgw, 30 kgw backpack carrying system in walking. It was efficient on the 10 kgw, 15 kgw fore-backpack carrying system in walking. 6. Magnitudes of EMG of Castrocnemius, Tibialis anterior, Vastus lateralis, Vastus medialis, were increased according to increasing weight road and were decreased on the 20 kgw, 30 kgw back-pack carrying system in walking.

토의식 수업을 적용한 수준별 소집단 협력학습이 학력신장에 미치는 영향

김성국 한국학교수학회 2001 韓國學校數學會論文集 Vol.4 No.1

Nowadays the number of students that is losing their interest as well as learning desire in mathematics is increasing because of lack of logical thought creative power and abstract expression that present-day mathematics requires by reason of discrepancy of extreme scholastic ability by speciality of mathematics. In these conditions, we reduce the number of learning depression by bringing about learning desire or learning interest on mathematics, and students team effective learning methods to be voluntary learning of discovery themselves that studies basic concepts, principles, rules through logical thought of students to solve difference of scholastic ability, thus we assumed that debate studies through small group activities in ability group would be one of ways to improve learning power, so the results of our research are as follows; 1.Debate studies through small group activities were very effective because of reinforcing the achivement level of students. 2.By this learning method, an individual or cooperrative learning was fostered, and lively discussions were accomplished. And learning attitudes of students were changed by the extension of cooperative learning abilities through advices or by themselves. 3.A personal opinion is payed regard by accepting an individual idea in the process of making questions. Learners can correct wrong concepts in the process of correcting wrong answers. So if we apply above-mentioned studies with easy contents from the lower grades, the effectiveness would increase as learners go to the higher grade. According to the results of various researches as follows; "The teaching-learning method oriented coopperative debate studies is effective to find solutions to mathematical problems." If small group activities are applied in the educational situation to search the course of a desirable cooperation teaming through small group activities to improve scholastic abilities for a discoverable problem-solving power. I think that the teaching-learning method oriented cooperative debate studies is one of the most desirable methods to increase the problem-solving ability.

고등학교 1학년 학생들의 인지수준과 과학의 물질 단원 내용수준 비교 분석 및 교사들의 인식

김성숙,박소영,정미현,류상미,강성주,박국태 韓國敎員大學校 敎育硏究院 2009 敎員敎育 Vol.25 No.4

The purpose of this study was to seek for improved teaching and learning methods by comparatively analyzing the cognitive level of 10th grade students and the content level of high school science textbooks's matter unit and examining the teacher's understanding of these issues. For this study, the cognitive level of 336 10th grade students from 4 areas were analyzed using SRT Ⅲ (Science Reasoning Task Ⅲ) and the content level of 10 scientific concepts selected from the matter unit of high school science textbooks were analyzed using CAT (Curriculum Analysis Taxonomy). How high school science teachers understood these issues was also examined. The result showed that 51% of the research subjects were the formal operational level, 30% of the transitional level, and 19% of the concrete operational level. The percentage of students of the formal operational level varied according to each school. The scientific concepts of the matter unit of the 6 high school science textbooks were mostly of the early formal operational level. However, the content level of the same scientific concept varied according to each textbook, since the level of each textbookordiexpdeining scientific concepts to students and the answers theyiexpected from students were different. Furthermore, high school science teachers considered the content level of the scientific concepts lower than the actual content level analyzed through teptsAT. Such d6 harmonyibetween the cognitive level of students and the content level of the scientific concepts and the wrong conceptt. Furtteachers of the content level of the scientific concepts effects the students' understanding of scientific concepts and teaching-learning methods. I Furder to solve the discordance between the level of students and scientific concepts and to increase the understanding of students of scientific concepts, teachers should develop the appropriate teaching and learning methods that considers the cognitive level of students and content level of scientific concepts, by analyzing the cognitive level of students and understand the content level of scientific concepts of science textbooks, prior to class. 이 연구는 고등학교 1학년 학생들의 인지수준과 고등학교 과학 물질 단원의 내용수준을 비교 분석하고, 이에 대한 공통과학 교사들의 인식을 알아봄으로써, 교수 학습 방법에 대한 시사점을 얻고자 하는 것이다. 연구를 위하여 4개 지역의 고등학교 1학년 학생 336명 을 대상으로 SRT Ⅲ(science reasoning task Ⅲ)를 사용하여 인지수준을 조사하였으며, 고등학교 과학 물질 단원에서 10개의 과학 개념을 추출하여 CAT (curriculum analysis taxonomy) 분석틀로 내용수준을 분석하였다. 그리고 이에 대한 공통과학 교사들의 인식을 조사하였다. 연구 결과에 의하면, 고등학교 1학년 학생들의 51%가 형식적 조작가 수준이었으나, 30%의 학생들과 19%의 학생들은 각각 과도기 수준과 구체적 조작기 수준이었으며, 형식적 조작기 수준의 학생 비율은 학교별로 차이가 있었다. 고등학교 6종 과학교파서에 제시된 물질 단원 과학 개념들의 내용수준은 대부분 초기 형식적 조작기 수준이었으니, 같은 과학 개념이라도 설명하는 수준과 학생들에게 요구하는 답변의 수준 차이로 인해 교과서별로 내용수준에 차이가 있었다. 그리고 과학교사들은 과학 개념의 내용수준을 CAT 분석틀로 분석된 실제의 내용수준에 비해서 낮게 인식하고 있었다. 이러한 학생들의 인지수준과 과학 개념의 내용수준의 불일치와 과학교사들의 과학 개념 내용수준에 대한 잘못된 인식이 학생들의 과학개념에 대한 이해도와 교수-학습에 영향을 미칠 것이다. 그러므로 학생들의 인지수준과 과학 개념 내용수준간의 불균형을 해소하고 과학 개념에 대한 학생들의 이해도를 높이기 위해서는 과학교사들이 학생들의 인지수준과 과학 개념의 내용수준을 사전에 파악하여, 학생들의 인지수준과 파학 개념의 내용수준을 고려하는 교수-학습 전략이 필요하다.

충돌제트가 분사되는 내부냉각통로에서의 3차원 유동특성 및 압력손실

주성국,이상우 國立金烏工科大學校附設生産技術硏究所 1997 産業技術開發硏究 Vol.13 No.-

Detailed three-demensional flow measurements and aerodynamic loss distributions inside internal cooling passage with jet impingement cooling are presented using five-hole probe. For a fixed inclination angle of 90 deg, the velocity ratio of the jets to free-stream is varied from 1.0 to 4.0. Results show that for low velocity ratio, a pair of conunterrotating vortices were presented, but high velocity ratios it was disappeared. It also show that aerodynamic losses were closely related to the secondary flow. In the case of the velocity ratio of 2.0, the secondary flow is the largest. Regardless of the velocity ratios, aerodynamic losses are decreased in rear region far from the jet injection hole.

물리 개념 모형 완성 활동이 고등학생의 물리 개념 학습 성취도에 미치는 효과

김정국,김성룡,김영민 부산대학교 과학교육연구소 2006 교사교육연구 Vol.45 No.-

The aim of this study is to investigate if learning through completing activities of physics conceptual model is more effective than learning through traditional teaching method based on didactical lecture. Completing activities of physics conceptual model is for the students to complete an incomplete conceptual model of physics given by the authors. For the study, four classes(140 students) from two high-schools were sampled and divided into experimental and control groups. After pretest, 3 periods of instruction were implemented, and then, post-test was taken. For the experimental group, instructions with completing activities of physics conceptual model were implemented, while, for the control groups, traditional instructions based on didactical lecture were implemented. According to the statistical analysis of test results, there was a meaningful difference statistically in post-test between experimental groups and control groups, while there was no meaningful difference statistically in pretest results between them.