步行者 交通流에 關한 硏究

成昌煥 영남이공대학 1982 論文集 Vol.11 No.-

Taking Daegu as a model city, I drew the following conclusion as the result of the survey and analysis of the specific character of the pedestrian traffic flow of the day time zone. 1. The average pedestrian dencity of the day time zone is 0.41 person to a square meter in the urban center, 0.61 person to a square meter in the outskirts of the city. The average density of the pedestrian traffic of the whole city is 0.33 person to a square meter, which is of low density. 2. The average walking speed is 1.34 meters per second in the urban center, 1.32 meters per second in the outskirts of the city and 1.37 meters per second in the whole city. 3. Walking speed and density have relation to the first regression, and the regression formula for the urban center including the outskirts of the city and the whole city is (6), (9), and (10). 4. The formula Q=K·V is not equal to the relation between the pedestrian traffic flow and density. The first regression like formula (12) through (14) comes into existence.

방사선조사가 Porphyromonas gingivalis에 미치는 영향

이창환,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.1

Purpose : The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). Materials and Methods : P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Results : Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fimA and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. Conclusion : These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

小麥과 大麥의 出穗期 및 成熟期差異에 관한 硏究

曺章煥 단국대학교 1985 論文集 Vol.19 No.-

This experiment was carried out to investigate the differences in mechanism pertaining to earliness between barley and wheat. Early, intermediate and late varieties of wheat and barley were tested for this experiment. The results obtained are as follows; 1. In contrast with barley, the average heading dates of early and intermediate varieties of wheat were 6 to 7 days earlier at Suweon, Daejon and Milyang. However, the average maturing dates of those wheats were 5 days later than those of barley. 2. The cumulative temperature total in wheat varieties, in comparison with barley, was about 106℃ greater from sowing to heading, 8℃ from heading to maturity, and 114℃ from sowing to maturity. 3. The daily mean temperature in wheat varieties was about 0.34℃ higher from sowing to heading, and 0.49℃ from heading to maturity than barley, suggesting that wheat requires higher temperature during the growth period. 4. The days to flag leaf emergence for many barley varieties under short daylength were shorter than wheat, but Olbori and Gangbori had the similar short daylength response to Greumil. on the other hand, Chokwang had considerably longer days to flag leaf emergence. It was generally appeared that the difference of days to flag leaf emergence within varieties was greater than that between the species. 5. The earliness in narrow sense for barley was shorter than wheat, and the varietal difference of this trait for wheat was greater than barley. 6. The young spike initiation of barley varieties proceeded more rapidly and linearly from sowing up to the middle stage of spikelet differentiation before winter season. After winter season, the stem elongated rapidly and the spike developed linearly. The young spike initiation of wheat varieties proceeded smoothly and non-linearly after sowing, but after young floral primordia initiation (stage Ⅳ-Ⅴ) in early spring, the young spike development started rapidly. In general, the young spike development in wheat, in contrast with barley, was two or three stage later and was less hastened by low temperature. 7. From these results it can be concluded that in breeding barley and wheat varieties with early maturity, the early start of stem elongation is very important in barley, and the early start of development of young spike, and rapid development under low temperature and short daylength are very important in wheat.

Fluoroacetate(Platol)중독 증상 연구 : 자살기도자를 중심으로

한창환,황주연,김경식,안석철 大韓神經精神醫學會 1984 신경정신의학 Vol.23 No.1

This study was designed to evaluate the clinical problems of fluoroacetate intoxication. The total number of the fluoroacetate intoxication patients who came to the emergency room of Han Gang Sacred Heart Hospital from Jan. 1, 1983 to Aug. 31, 1983 were 96 cases. Among them, 41 attempters who were consulted to the psychiatrist were evaluated and observed in detail. The following results were obtained. 1. The rodenticide poisoning accounts for 37.2% of all toxic substance intoxication(total 266 cases) at Han Gang Sacred Heart Hospital from Jan. 1983 to Aug. 1983. Among them, 96 cases(36.1%) of fluorcacetate intoxication were observed. 2. Female was affected 2.4 times more frequently than male. 35.5% of total cases belonged to age group 21∼30years, when incidence was most prevalent 3. As the route of drug obtainment, supplement were commonest(63.3%), purchase in 29.4%. 4. CNS disturbances such as drowsiness, stupor, semicoma and irritability were observed in 75.6% of the cases. Speech disturbances such as dysarthria, childish speech was observed in 9.8%of the cases. Convulsion(29.3%), tremor(12.2%) spasm and twitching(4.9%) were also frequently observed. Tachycardia was found in 43.8% of the cases and other frequent symptoms were nausea and vomiting(53.7%), abdominal pain(34.2%), mild or high fever(26.8%). Lower calcium(below 9mg) was found in 29.3% of the cases and lower potassium(below 3.5mEq) was found in 22.0% of the cases. EKG findings revealed QT prolongation(22.0%), ST-T change(22.0%) and u-wave, RBBB, and PVC(14.6%). 5. 92 cases(95.8%) recovered without sequelae and 4 cases(4.2%) expired.

對時變動慣性系인 航空機의 縱의 動安定解析 : 第1報, Mass Parameter Vector의 導入 1st Report, Method of Analysis due to the introduced Mass Parameter Vector

裵昌煥 연세대학교 산업기술연구소 1974 논문집 Vol.5 No.1

One of the problems in practical applications of the dynamic stability characteristics and flying qualifications and adaptive controls of aircraft is to vary the mass, components of inertia tensor and C.G. position in fore and aft. However, the effects due to such variations are only considered in the problems of design and control of aircraft, partially. Therefore, in this study, 1). Mass parameter vector ??⊂Ω(its apreciable domain composed of every parameters) to correspond their time-varying elements was newly defind, and then introduced into the equations of motion. 2). The result of root locus solution to the time-varying longitudinal characteristics equation was represented to be able to consider a locus of ??: a set of roots ⊂?: root space as a set of images due to the mapping of ??. 3). Also, the result of a calculation for the example airplane was discussed on the basis of above analytical method.

國樂 音階의 考察

張昌煥 서울 敎育大學校 1979 論文集 Vol.12 No.-

韓國의 都市規模別 計劃人口 密度에 관한 硏究

崔昌煥,吳錫氣,安相哲 동아대학교 공과대학 부설 한국자원개발연구소 1977 硏究報告 Vol.2 No.1

Population is concentrated urban region in Korea. It is leading to over-massed dwelling of urban region and was made worse by the residential environment. This study is comparison of population density by the city size of the Master Plan in Korea. Analytical method decide ranking at thirty-five cities of Korea by the census in 1975 and it divided into city size which is Metropolis (over a million), Large City (300-1,000 thousand), Middle Town (100-300 thousand) and Small Town (under 100 thousand persons). In this study, population density for possible developing area was computed by the presumption of population in 1986. The results of this study are summerized as follows: 1). Population plan was underestimated in Metropolis (Seoul, Busan and Daegu) by policy agreement. 2). The possible developing area's population density will proper in under-a million's city. 3). The Metropolis cause an advance in the population density of possible developing area in 1936 and will bring about a change for the worse of residential environment. (362persons/ha.) 4). A plan of solution to a population density's rising is necessary re-enforcement of re-completed master plan and the plan of arrangements for residential area must be considered in the plan of re-completed master plan.

再開發地區指定의 設定基準에 관한 硏究

崔昌煥,吳錫氣,安相哲 동아대학교 공과대학 부설 한국자원개발연구소 1982 硏究報告 Vol.6 No.1

This study is for the establishment standard on the blighted degree in urban renewal area. The factors of establishment standard is population density, ratio of a building site, size of a building site, diffusion ratio of road, ground coverage, volume ratio of building, dwelling space of a person, total floor space per building, and others. As a result of this study, the standard of renewal area appointment is as follows. 1) Population density … over 300 person per hectare. 2) Ratio of a building site … over 70 percent. 3) Size of a building site … under 120㎡ 4) Diffusion ratio of the road … under 25 percent. 5) Ground coverage of a building … over 55 percent. 6) Volume ratio of a building … over 120 percent. 7) Dwelling space of a person … under 20㎡ 8) Total floor space per a building … under 80㎡ 9) Age of building … over 40 years.

서보모터의 견실한 속도제어

김창환 대전대학교 산업기술연구소 2001 산업기술연구소 論文集 Vol.12 No.1

In this paper, we propose a generalized robust control scheme for servo motors. Our controller consists of both a model based feed-forward controller and a stabilizing feedback controller. The feed-forward controller is designed such that the output of nominal plant tracks perfectly the reference velocity command with desired dynamic characteristics. The feedback controller stabilizes the overall closed loop system. Furthermore, the feedback controller contains a free function that can be chosen arbitrary. The free function can be designed so as to achieve both the suppression of disturbances and the robustness to model uncertainties. In order to illuminate the superior performance of our control scheme to the conventional ones, we present some simulation results

반복학습제어를 이용한 Switched Reluctance Motor의 맥동토크 최소화

김창환 대전대학교 산업기술연구소 2000 산업기술연구소 論文集 Vol.11 No.2

The generated torque of switched reluctance motors(SRMs) is highly nonlinear, which makes it difficult to determine the reference current commands for minimal torque ripples. In this paper, we present a computationally simple learning control method which minimizes torque ripples of SRMs. Our learning control algorithm can drive the steady state speed error to zero and, furthermore, can be used to identify the reference current commands minimizing torque ripples in look-up table form. In order to justify our work, we present some computer simulation results.