소형 풍력발전시스템을 위한 계통연계형 인버터에 관한 연구

李大東,沈在明,張錫九 한밭대학교 2004 한밭대학교 논문집 Vol.21 No.-

We imported technology from abroad and studied grid connected type wind power generation owing to the lack of technology, but nowadays we conduct researches in many quarters because of national supporting policy. However, the research speed is delayed by burden for research expense which wind power generation is huge. Therefore, in order to experiment on various kinds of the wind turbine, generator, and converter easily, the development of wind power system is demanded powerfully among research workers. In this paper, in order to satisfy this need, I suppose a new simulation development environment. The electric power generated by wind is changing, so by using the converter, schedule electric power must be provided. Therefore, in this paper, I explained an element of the converter of the wind power generation system by showing two examples. First, Diode rectifier and current controlled voltage source inverter by using IGBT(Insulated Gate Bipolar Transistor) element was used in the wind power generation system. Second, rectifier for control by using IGBT and current controlled voltage source inverter by using IGBT element was connected the grid. Simulation for two examples of grid connected type wind power generation system uses PSCAD/EMTDC and analyzed the result.

지역전통문화의 디지털 콘텐츠와에 관한 연구

이규식,박정민,김태곤,홍석구 慶北專門大學 2003 慶北專門大學 論文集 Vol.22 No.-

It investigates the website and a technique in order to make the culture property of the area with digital contents, it presented a method to make digital contents through investigation of Young-Ju area culture property. The results of this study ① It minimizes the loss of information ② Must come to be processed with the form which corresponds in objective of information delivery ③ for the result, It is necessary to grafting on new digitizing techniques.

Methoxyverapamil이 血厭에 關與하는 藥物의 作用에 미치는 影響

高錫太,李漢九,羅漢光 조선대학교 약학연구소 1992 藥學硏究誌 Vol.14 No.1

Methoxyverapamil, Ca^2+ chamnel blocker, inhibited the pressor actions of norepinephrine and angiotensin Ⅱ, and the depressor action of isoproterenol, while did not influence the pressor actions of tyramine and epinephrine. and the depressor actions of acetylcholine, pilocarphine, histamine and serotonin in rabbit.

미생물 초기부착과 생물막 성장에 미치는 기질의 C/N 비

박영식,이석렬,나영수,서정호,송승구 부산대학교 환경문제연구소 1997 環境硏究報 Vol.15 No.1

Pyrantel Pamoate(Combantrin)에 依한 蛔蟲症의 減量療法

徐丙卨,李純炯,趙昇烈,姜信榮,梁龍石,黃邱一,朴定圭,李水月 中央醫學社 1973 中央醫學 Vol.25 No.4

The mass treatment trial with low dosage of pyrantel pamoate against Ascaris lumbricoides infection was conducted to school children in rural areas of Korea. A comparative trial in the use of piperazine salt, santonin-kainic acid complex in the treatment of ascariasis was also attempted to evaluate the efficacy of' pyrantel pamoate. A total of 804 Ascaris infected school children selected out of 822-positives, who were screened from the total 1, 699 collected specimens, were classified into 7 groups. One of the three kinds of anthelmintics, i.e., pyrantel pamoate, piperazine adipate and santonin-kainic acid complex was administered to each group according to the planned regimen. For the evaluation, the egg negative conversion rate(cure rate) and egg reduction rate were calculated 4 weeks after treatment on 623 follow-up cases with the obtained results from the stool examinations (Cellophane Thick Smear Method and Stoll's Egg Counting Technique). The results obtained were; 1. The egg negative conversion rate was the highest in pyrantel treated groups (Group 1, 2, 3), santonin-kainic acid complex treated group (Group 7) coming next, and the lowest in piperazine treated groups (Group 4, 5, 6). 2. The reduction rates were also obtained just as the same order of the above results. 3. Among the pyrantel pamoate treated groups, the low dosage groups (Group 2 8: 3) showed 90.6% and 85.7% of negative conversion rate, and 99. 2% and 98. 2% of reduction rate respectively, while 94.1% of negative conversion rate and 97.9% of reduction rate were obtained in the conventional dosage group (Group 1). 4. On the analysis of efficacy in the groups treated with piperazine adipate, the best results were. shown in 2 or 3 consecutively treated groups (Group 4 &.- 6) under the supervision of qualified doctors, and the worst was in the group treated with 2 consecutive administration by teachers without supervision (Group 5). 5. The side reactions were so negligible in all the trial groups that none of the treated cases complained about the known side effect of those anthelmintics. From the present study, it can be suggested that the pyrantel pamoate is the most effective among three drugs, and also be recommended to apply the low dosage schedule of pyrantel pamoate in the masstreatment of ascariasis to reduce the expense of masstreatment.

電氣相似模型에 依한 흙속의 浸透流 解析

權武男,具賢謨,李相昊,李錫健 慶北大學校 1989 論文集 Vol.47 No.-

This study was performed to evaluate the usefulness of the electrical analogue model in porous medium. Experimental values by the electrical analogue models were compared with those by the sand models and theoretical values by the fragment method. The results obtained are as follows: 1. The flow lines into the sand model were changed according to rising the upstream water level but those of the electrical analogue model weren't changed, and the equipotential lines were revealed to be almost same in the two kinds of models above. 2. The seepage quantities by the fragment method and the electrical analogue model were a little more than those by the sand model. 3. The exit gradients by the fragment method were steeper than those by the sand model and the electrical analogue model. 4. The seepage quantities were increased in proportion to the increment of the exit gradients. By means of the results above, it may be given as a conclusion that the electrical analogue model test is more useful than the sand model test for appling to seepage flow in the field condition, because the electrical analogue model test is more accurate and simpler. Then, the electrical analogue model test will be able to apply to the three-dimension seepage flow problems.

생약성분 항암제 Tianxian의 흡수동태에 관한 연구

양은정,김원배,심창구,이민화,정석재 서울대학교 1995 藥學論文集 Vol.20 No.-

와우 갑각 전기자극 뇌간유발반응용 원추형 전극의 개발

허승덕,정동근,강명구,김리석,고도흥 한국음성과학회 2003 음성과학 Vol.10 No.4

This paper introduces a new zinc coated copper wire electrode with coiled cone shape which has low surface resistance and tolerance to the motion artifact for promontory stimulation electrically auditory brainstem responses (PSEABR). Auditory brainstem responses (ABR) can be used to predict hearing threshold level with a great deal of accuracy particularly for a young child who cannot cooperate mechanically and some hearing impaired who are exaggerating a hearing loss for economic compensation. While severe profound sensorineural hearing losses may not be implemented by auditory potentials, PSEABR is proven as a useful tool even for some sensorineural related hearing impaired. It was shown that PSEABR gives the electrical stimuli to promontory of the cochlear instead of giving acoustic stimuli. For this reason, PSEABR can be used as an alternative for cochlear implantation, and can also be used as an optimal device selection and neural information for MAP. It was found that the role of electrode is very important in PSEABR. Even though this cone-shaped electrode was applied in animal experiments, waveforms are well produced by PSEABR. Thus, it was concluded that cone-shaped electrode turned out to be a useful preoperative audiological evaluation tool in deciding time for cochlear implantation surgery.

가공 송전선의 부식진단시스템 개발

김성덕,심재명,정원일,장석구,이승호,김영달 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

A diagnosis method to inspect deterioration in overhead ACSR conductors is discussed in this paper. Corrosion would be occurred by various and complex factors such as atmospheric indices, installation environment and metallic configuration, but must of corrosions are mainly due to atmospheric corrosion, galvanic corrosion and crevice corrosion. Such corrosion in ACSR would lead to be zinc loss of galvanized steel strand and reduction of cross section area of aluminum strand and it may be mechanical strength of power conductor in service to reduce. Global corrosion can be treated as average corrosion occurring on the conductor and it would appear to any material variations by the elapsed years of the conductor in the atmosphere. Therefore, as estimating the loss rate of tensile strength of aged conductor corresponding to the elapsed years, it would be possible to quantify global corrosion indirectly to a prediction function. Through such results, loss degree for ACSR 97[mm2] is classified to 4 ranges. i.e., no loss, possible loss, partial loss and sever loss. Both local and global corrosion could not be detected by visual inspection, but we proposed a corrosion detector system using a solenoid eddy current sensor in order to inspect such corrosion for old conductor. Corrosion detecting system is constituted to a corrosion detector and a ground station controller. Corrosion detector consists of sensor coil and sensing head, signal processing unit, data communication system, motor driver and controller, u-processors and power supply. After considering operation and manipulation in the field, motor, battery and wheels were selected and designed in order to reduce the weight of corrosion detector. Programs for u-processors, measurement program operated in a PC were also developed. Before testing the corrosion detector in the field, several experiments were carried out in the laboratory for artificial corroded samples. Sensor performance, mechanical tests such running ability and weight, and RF data transmission as well as measurement program were examined. After testing a simple corrosion detector system in the laboratory, several filed tests were carried out in practice transmission lines installed in domestic area. Finally, the suggested corrosion detecting system shows an effectiveness to detect local corrosion in acted conductor in practice.

청각 자극용 전기자극기 개발

허승덕,정동근,김리석,김광년,강명구,김재룡,김기련 한국음성과학회 2004 음성과학 Vol.11 No.3

This paper introduces a development of an electrical stimulator for auditory stimulation. The electrical stimulator is useful in neurotological diagnosis, audiological evaluation, candidate selection for cochlear implantation, optimal device selection and decision making of MAP strategy for severe-to-profound hearing impaired persons. The development was based on sound parameters of auditory brainstem responses and auditory electrophysiological characteristic such as effective firing of auditory nerve and recording evoked potentials during refractory period of neuron. Besides pulse parameter could adjustable by programming for more varied electrical stimulation evoked response audiometry. Using the electrical stimulator, electrical square pulse was applied to promontory, and electrically evoked auditory brainstem response and electrically middle latency response were successfully recorded in cats.