변압기의 유동대전에 대한 유속 및 유온의 영향에 관한 연구

정원용,고희석,박상현,박재윤,김정달 慶南大學校 附設 工業技術硏究所 1992 硏究論文集 Vol.10 No.-

本 硏究에서는 固體-液體 界面에서 液體가 流動할 때 발생되는 유동대전에 대한 硏究로서 大容量 變壓器내에서 絶緣油가 통과하는 通路를 모델링한 帶電 파이프를 設計·製作하고 대전 파이프내의 油路形狀에 따른 流動電流를 側定·分析하였다. 이러한 實驗으로부터 얻은 결과는 다음과 같다. 1) 流動電流는 油速의 增加에 따라 線形的으로 增加하였으며, 油溫의 增加에 따라 약 46[℃]이하에서는 增加하고 그 이상에서는 感少한다. 2) 絶緣油의 흐름이 원활하게 되도록 油路形狀을 변화시키면 流動電流는 感少한다. In this paper, the streaming electrification generated at a solid-liquid interface is studied. Electrification pipe modeled on the oil path of the high power transformer is designed and manufactured. The Streaming current is measured as a function of oil velosity, temperature at each electrification pipe. From the result of this study the following conclusions are obtained. 1) The streaming current increases linearly with increasing of oil velocity and It increases at lower temperature than 46[℃]and decreases at higher temperature than 46[℃] 2) The smoother the flow of insulating oil is the less the streaming current decreases.

PID 制御器의 最適 自動 調整

鄭源鎔,金鳳載,李壽欽,朴賢泰 慶南大學校 附設 工業技術硏究所 1994 硏究論文集 Vol.12 No.-

In this paper, we propose a new method to deal with the optimal auto-tuning of the PID controller that is used to control process in various fields. First order delay system that was modeled from the unit step response of the system is Pade-approximated, and initial PID parameters are determined by the Ziegler-Nichols method. This method requires calculation of the weight function that includes the maximum overshoot, damping ratio, rising time and setting time by analyze the response of system. Finally, repeating these processes, we can find the parameters of PID controller so as to minimize the weight function. This method has a good adaptability even though variations in characteristics and dead time of the system.

측두부에 발생한 Cranial Fasciitis의 치험례

정현권,변준희,이종원,이종건,임풍,박성찬 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

Cranial fasciitis is a rare morphological variant of nodular fasciitis. It is characterized by a rapid growing fibroblastic proliferative lesion that develops chiefly in childhood. It has varying size and involves the soft tissues of the scalp and the underlying skull. Accurate diagnosis and surgical excision is the key to management. Prognosis is good with rare recurrence. We report a case of cranial fasciitis in the temporal fossa of a 20-month-old girl and present a review of the literature.

산처리된 Kaolin으로 부터 β- Sialon의 합성

문종수,최태현,배원태,전병세 慶南大學校 附設 工業技術硏究所 1988 硏究論文集 Vol.6 No.-

불순물의 수준을 저하시키고 비표면적을 증가시키기 위하여 카올린을 산처리 하였다. 이 산처리한 카올린을 카본 블랙을 환원제로 하여 1250℃에서 1350℃까지 1시간에서 7시간 동안 β-Sialon 합성 거동을 조사하였다. 산처리한 시료는 알칼리 함량이 급격히 저하되고 비표면적은 상당히 증가하였다. 또한 표면이 심하게 침식되었으며 β-Sialon이 쉽게 합성 되었다. Kaolin was treated by acid in order to reduce impurity level and increase it's specific surface area. β-Sialon synthesis was investigated using carbon black as a reducing agent at 1250℃-1350℃(for 1-7h) under N₂atmosphere. Alkali content was highly decreased and specific surface area was also relatively increased in acid treated sample. Surface was highly etched and β-sialon was easily formed in acid treated sample.

표재성 방광 이행상피세포암에 있어서 방광내 항암제주입요법 밀 면역요법

설종구,신보현,하용원,김윤종,노안식,손성용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.2

Intravesical chemotherapy and immunotherapy will commonly eradicate residual papillary transitional cell carcinoma or carcinoma in situ(CIS) and clearly reduce the short-term incidence and rate of tumor recurrence. So I reviewed the effects and complications of different therapeutic agents(thiotepa, mitomycin-C, epirubicin, adriamycin, bacillus Cal mette-Cue'rin(BCG)) in superficial bladder cancer confirmed with histopathology, with the literatures. Bladder cancer were recurred more commonly in multiple tumors(50.6-56.3%), high grade tumors(52.6%) rather than in single(30.9%) and low grade(31.6%). And recurrence rates according to therapeutic agents were 83.3% in mitomycin-C, 71.4% in thiotepa, 50.0% in epirubicin, 46.6% in adriamycin and 32.6% in BCG. But incidence of complications were highest in BCG(50.5%). So sufficient preventive manuevers should be needed before intravesical theraphy, especially in BCG immunotherapy.

흰쥐에 Xylene 반복 투여가 Xylene의 대사에 미치는 영향

전태원,이혜자,윤종국,이상일,조현국 THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 1999 Journal of biomedical laboratory sciences Vol.5 No.1

실험동물에 xylene의 반복 투여가 이물질의 대사에 어떠한 영향을 미치는지를 알아보기 위하여 흰쥐에 m-xylene과 olive oil의 동량혼합액을 체중 100g당 0.25ml씩 2일 간격으로 1, 4, 8, 12 및 16회 복강으로 투여한 다음 마지막 투여 24시간 후에 처치하여 다음과 같은 결과를 얻었다. 요 중 m-methylhippuric acid 함량은 m-xylene 4회 투여군의 경우 1회 투여군에 비하여 약 56%의 유의한 증가를 보였으며 이후 12회 투여까지 유사한 결과를 나타내었으나 m-xylene 16회 투여시에는 xylene 1회 투여군 치와 유사한 치로 감소되었다. 그리고 간조직의 microsomal aniline hydroxylase와 alcohol dehydrogenase 활성은 m-xylene 12회 투여시 까지는 대체적으로 점진적인 증가를 보였으나 이후 16회 투여시에는 12회 투여군에 비하여 유의한 감소를 보였다. 또한 aldehyde dehydrogenase 활성은 m-xylene 투여 회수에 비례해서 전 실험기간 동안 감소되었으며 특히 16회 투여군에서 본 효소활성의 현저한 감소를 보였다. 한편 본 실험조건에서 투여기간에 따른 진자현미경적 미세구조의 변화는 초기에 활면소포체의 증식이 보이다가 16회 투여군에서는 활면소포체가 감소되고 조면소포체가 증가되었다. 이상 실험결과는 흰쥐에 있어서 xylene 투여 회수에 따라서 요 중 m-methylhippuric acid의 농도 변동이 초래되며 이는 효소단백 유도에 따른 xylene 대사효소 활성 변동에 기인된 결과로 생각된다. To evaluate the effect of repeated treatment of xylene on its metabolism, m-xylene (0.25ml of 50% in olive oil/100 g body weight) has been intraperitoneally given to the rats 1, 4, 8, 12 and 16 times every other day. m-Xylene was once more administered to the animals after 24 hrs since last injection of it. And then the animals were sacrificed after 24 hrs. Four times xylene treated rats showed the significantly elevated urinary m-methylhippuric acid, compared to those treated with the singe dose of m-xylene with the continued similiar high levels of urinary m-methylhippuric acid up to the animals pretreated 12 times and then those treated 16 times defined the significantly decreased urinary m-methylhippuric acid compared to those treated 12 times. On the other hand, hepatic aniline hydroxylase and alcohol dehydrogenase activities demonstrated a gradual increase from the first group to the 12 times xylene-treated animals, but those treated 16 times showed the significantly decreased value compared with the 12 times treated-group. And aldehyde dehydrogenase activities in rats treated with m-xylene 8, 12 or 16 times were significantly decreased compared to those pretreated one or four times. In the early stage of xylene administration, proliferation of SERs were seen whereas SERs were decreased and RERs were clearly increased in xylene-treated rats 16 times. These results indicate that the frequency of xylene injection may influence upon the changes in xylene metabolite, m-methylhippuric acid and it may be due to induction of xylene metabolizing enzymes.

인터넷 홈페이지를 활용한 우리 나라와 일본 중학교의 과학교육 실태 비교 연구

윤치원,김종균,박영철,김현섭 공주대학교 사범대학 과학교육연구소 1999 과학교육연구 Vol.30 No.1

최근 인터넷의 보급이 보편화되면서 교육현장에서도 인터넷을 활용한 교육이 활발히 시도되고 있다. 이것은 인터넷의 장점을 교육현장에 이용하면 학습지도에 필요한 정보를 용이하게 입수할 수 있고 개인이나 제도교육에 관한 정보를 널리 공유할 수 있으므로 교육활동의 질적 개선을 기대할 수 있기 때문이다. 종래는 지리적인 제약 때문에 개인이 수입할 수 있는 정보에는 한계가 있었으나 인터넷을 활용하면 제한된 정보나 개인의 교류 범위를 넘어선 전국적, 세계적인 정보의 수집 수단으로 활용할 수 있다. 이러한 관점에서 본 연구는 인터넷상에 올라와 있는 우리 나라 중학교 홈페이지와 우리와 교육환경이 유사한 일본 중학교 홈페이지의 구성 내용을 비교하고 특히 인터넷을 활용한 과학교육 실태를 비교·분석하여 인터넷을 과학교육 매체로 활용하는 방안을 찾는데 목적을 두고 수행하였다. 본 연구의 대상 학교로는 우리 나라의 경우 인터넷상에 검색이 가능한 211개 중학교 모두를, 일본의 경우는 검색 가능한 1022개 중학교 중 200개 학교를 표본으로 추출하였다. 이어서 학교의 홈페이지 구성내용을 `학교 일반정보' `정보공유' `교수 학습정보' 기타정보' 등 4개 분야로 나누어 비교 분석하였는데 특히, `교수 학습정보' 분야 중 과학교과 자료와 연결된 사이트 그리고 학생 탐구자료 내용을 집중적으로 비교·분석하였다. 그 결과 우리 나라 중학교의 홈페이지 개설 학교 수는 급격히 증가하였으나 과학교육에 관련된 내용은 매우 빈약하였고, 있는 내용도 대부분 외국 자료를 연결하여 놓았기 때문에 중학교 학생들이 이용하기에는 많은 어려움이 있을 것으로 생각되었다. 일본의 경우는 과학교육에 활용할 수 잇는 자료가 비교적 풍부하고 연결된 사이트도 대부분 자국어로 되어 있었으며, 그 내용도 학생의 관찰, 조사, 실습 등 학생의 탐구활동 내용이 소개되고 있어 인터넷을 활용한 과학교육에 유용할 것으로 생각되었으며, 이것은 우리 나라에서 인터넷을 활용한 과학과 교수 학습 활동에 유용한 과학자료를 개발하는데 좋은 참고 자료가 될 것으로 생각되었다. In recent years, and increased number of junior high schools are attempting to `utilize the internet as an instruction aid'. The internet provides easy access to wide ranges of scientific information which facilitate teaching and learning activities. Especially in the areas of shared research and general information and personal communication. Prior to the existence of the internet, people were limited by geographical locations; however, modern internet use is international and information can be shared throughout the world. From this point of view, this study was compared the line up of Korean and Japanese junior high school homepages. This comparison is valid because the two countries educational systems are grossly similar. We proposed analysis of science education in the homepage on the internet to find the method of science education. In Korea the objective schools of this study are all 211 junior high schools of which was able to search to use internet and in the case of Japan 2000 junior highschools as samples of which 1022 junior highschools that was able to search to use internet. Four main areas of the study were examined; general school information, the supply of information, information for teaching and learning and other links. Elements of homepage were classified into 4 groups based on these divisions. Informations from Korea and Japan contained in the teaching and learning site was subdivided into scientific curriculum and student investigational material. These subdivisions were analyzed and the differences between the two countries were as follows. Although the Korean junior high school homepages were rapidly increasing they were lacking in quality. It was also evident that many linking sites are written in foreign languages other than Korean. Without a translative program to interpret these, Korean students would be unable to take advantage of them. Japan had a greater quality of material used for science education Linking sites are written in the Japanese Languages. Japan appears to have an intensified focus on the useful development of scientific material and science education through the use of the internet. This enhances studied investigation, activities of observation, research, and investigation. The overall practice and performance of the Japanese studies is greatly enhanced through their ability to easily access the internet.

대전지역 소아 야뇨증에 관한 역학 조사

이재현,하용원,임재성,윤율로,설종구 충남대학교 의과대학 지역사회의학연구소 2000 충남의대잡지 Vol.27 No.2

Purpose: Nocturnal enuresis is defined as at least one wet night per month in children older than five years of age. Despite being a common disorder in children, not many reports about prevalence of enuresis in Korea have been written. To establish the prevalence of childhood enuresis in Taejon, an epidemiologic study was performed. Materials and methods: We evaluated 1,030 preschool and elementary school children living in Taejon city. The ages were between 5 and 10 years-old and the mean age was 7.5 years-old. The percentage of boys was 52.4% and the girls' was 47.6%. The questionaires was completed by the parents. Results: The overall prevalence of enuresis in Taejon city was 7%. The prevalence of enuresis was higher in boys(54.2%) than in girls(45.8%). The prevalence of primary and secondary enuresis was 55.6% and 44.4%, respectively. The inability to wake up in order to void because of deep sleep was 29.2% and positive family history was 20.8%. On the aspect of enuretic frequency, one episode per month was most common. The cases combined with diurnal enuresis were 9.7%. Among the enuretic children, the most common traditional treatment was self-voiding by awakening during night and most favored treatment was herbal medicine. Conclusion: These data show that the prevalence of nocturnal enuresis in Taejon city is lower than in other countries. It's prevalence is related to the positive family history, guilt feeling, diurnal enuresis, and early sleeping. However, concerning the prevalence of enuresis, there is statistically significant difference only in family history.

정상인과 뇌졸중환자에서 운동유발전위의 평가

김동현,박종현,권오상,김두응 중앙대학교 의과대학 의과학연구소 1997 中央醫大誌 Vol.22 No.2

Since the development of magnetic stimulation as a way of assessing the function of central motor pathways, various neurologic diseases have been investigated by motor evoked potentials(MEP). This study was carried out to evaluate the usefulness of clinical application of MEP to the stroke patients. MEP were elicited with transcranial cortical stimulation using a magnetic coil in 21 healthy subjects and 18 stroke patients. Average of age was 37.5±18.0 and 63.7±7.7 years in normal and patient groups respectively. All stroke patients had a mild to severe clinical unilateral motor weakness, and also were proven to have unilateral infarction or hemorrhage at various regions of brain radiologically. During MEP studies, neither significant side effects nor pin were encountered. MEP latency of abductor pollicis brevis(APB) and extensor digitorum brevis(EDB) in controls measured 22.4±2.0 msec and 41.8±2.9 msec respectively. Normal central motor conduction time(CMCT) was 9.7±1.6 msec and 19.3±2.3 msec respectively. The amplitudes of MEP were not reliable due to great variability. Abnormal responses were noted in 5 patients on the APB and in 12 patients on the EDB motor evoked potentieal studies. Mean latency and CMCT were significantly prolonged in involved sites of the other 16 patients, comparing with control data. Prolonged latency and CMCT, increased inter-side difference of CMCT. Any potential was not a useful indicator in determining abnormality of MEP study. More paralyzed patients were apt to show abnormal responses in MEP studies. There were also more abnormal results during acute stage compared with chronic stage More abnormal results were observed in the patients with cerebral cortex or corona radiata involvements. It is suggested that MEP study is a useful and sensitive method in the evaluation of stroke patients and be a effective method for further understanding of central motor system.

규조토로부터 β-Sialon의 합성

배원태,전병세,최태현,문종수 慶南大學校 附設 工業技術硏究所 1989 硏究論文集 Vol.7 No.-

카올린에 비하여 Al₂O₃의 함량이 낮은 규조토로부터 β-Sialon을 합성하였다. 불순물의 함량을 저하시키고, 반응을 증대시키기 위하여 규조토를 산처리하였다. 산처리하므로써 알카리 함량이 저하되고, 비표면적은 증가하며, 또한 Al₂O₃의 함량이 낮은 규조토를 사용한 β-Sialon에서는 미반응 Al₂O₃가 존재하지 않았다. β-Sialon was synthesized from diatomaceous earth which had the lower content of Al₂O₃ than kaolin. Diatomaceous earth was treated by acid in order to reduce impurity level and to increase reactivity. Contents of alkali were reduced and specific surface area was increased in acid treated samples. Free Al₂O₃ did not exist in the final samples which were synthesized from the low Al₂O₃ contented diatomaceous earth.