Equivalent Circuit Analysis of Induction Motors Considering Magnetic Saturation for Automotive Applications

Su‑Jin Lee,김성일,Pil‑Wan Han,김창업 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

This paper deals with the characteristics analysis of 3-phase induction motors for electric power steering applications by combining fnite element analysis with an equivalent circuit model. Induction motors for automobiles have high magnetic saturation due to size limitations. Accordingly, to improve the accuracy of the equivalent circuit analysis, it is necessary to consider the magnetizing reactance according to the magnetizing current. An equivalent circuit analysis method that takes into account the magnetic saturation of 3-phase induction motors is proposed and verifed through a test.

한강하구지역에서 월동하는 재두루미(Grus vipio)의 개체군 감소

이화수(Hwa-Su Lee),신주열(Ju-Yeol Shin),이시완(Si-Wan Lee),강태한(Tae-Han Kang),윤순영(Soon-Young Yoon),김정수(Jungsoo Kim) 한국조류학회II 2012 한국조류학회지 Vol.19 No.4

김포시와 고양시 일대의 한강하구 지역은 우리나라에서 재두루미의 가장 중요한 월동지 및 중간기착지로 알려져 있지만, 이 지역의 조류 서식환경은 심각한 개발압력과 인간의 간섭으로 인해 지속적으로 나빠지고 있다. 따라서 본 연구에서는 2007-2008년과 2011-2012년의 월동시기에 본 지역에 도래하는 재두루미를 대상으로 월동 개체군 크기 변화와 월동지역 내에서 과거와 현재의 취식지역 이용 현황 등을 조사하여 개발행위가 이들의 서식에 미치는 영향을 확인하였다. 본 지역에서 월동하는 재두루미 개체군은 평균 124.9개체(2007-2008년)에서 59.0개체(2011-2012년)로 감소하였으며, 주요 취식지역에서 확인된 개체수는 평균 77.7개체에서 24.1개체로 감소하여 월동개체군의 감소폭에 비해 주요 취식지역의 이용 개체수의 감소폭이 더 크게 나타났다. 유형별 분석에서는 가족군에 비해 무리군의 개체수가 많이 감소한 것으로 나타났으나, 홍도평 지역의 가족군 이용 개체수는 변화가 나타나지 않았다(Mann-Whitney test. Z=-0.26, p=0.979). 그리고 과거 다수의 재두루미가 주요 취식지역으로 이용하였던 송포동과 평동지역은 2012-2013년 조사에서는 거의 이용하지 않는 것으로 나타났다. 이는 위 지역의 개발행위(예: 제 2자유로 건설 등)와 깊은 연관성이 있는 것으로 생각된다. Han-river estuary in Gimpo and Goyang city is well known as one of the most important wintering and stopover sites for migrating White-naped Crane (Grus vipio) in Korea. Nowadays, habitat quality of this area is getting worse due to serious development pressure and high human disturbances. So, we wanted to know whether development actions affected total wintering population change in Han-river estuary and feeding group pattern of White-naped Crane in main feeding habitats between the 2007-2008 and 2011-2012 wintering period. Average wintering population was decreased 124.9 to 59.0 and population of main feeding site also decreased 77.7 to 24.1. But decrease rate of main feeding site population was higher than total wintering population. Non-family feeding population was more decrease than family feeding population in the flock type analysis. But family feeding population of Hongdopyong was maintained from past and present (Mann-Whitney test. Z=-0.26, p=0.979). However, almost all White-naped Crane din not use both feeding sites, Pyong-dong and Songpo-dong, where were deteriorated habitat quality by human act.

청국장 醱酵期間에 따른 組織學的 變化에 관한 硏究

이상건,윤정의,이수한 서울保健大學 1991 論文集 Vol.11 No.1

피라미를 이용한 젓갈 제조에 관한 연구

이수한 서울保健大學 1995 論文集 Vol.15 No.1

담수어의 식품이용성을 높이기 위해 피라미를 원료로 젓갈 제조시 식염을 고염농도(20%)와 저염농도(8%)로 마른간법에 의해 시험제조 후 저온 (5℃)과 상온 (20℃)에서 숙성시키면서 발효 시간, 식염의 농도 및 온도에 따른 일반성분, 생균수, pH, 산도, 아미노태 질소 및 VBN의 경시적 인 변화를 비교한 결과는 다음과 같다. 1. 숙성기간동안 일반성분 변화는 거의 없었으며, 원료 피라미의 수분은 74.34%, 조단백질 13.49%, 조지방 7.06% 및 조회분은 3.1%이었다. 고염농도 젓갈의 수분, 조단백질, 조지방 및 조회분 함량은 62.28%, 10.04% 5.02% 및 21.53% 이며, 저염농도 젓갈의 수분, 조단백질, 조지방 및 조회분 함량은 71.06%, 11.68%, 5.95% 및 10.61%이었다. 2. 생균수는 저염농도에서 제조직후 10^(6) cfu/g 에서 200℃ 숙성시 4일까지 10^(5) cfu/g으로 감소한 후 증가하여 30일 이후부터는 10^(8) cfu/g을 유지하였으며 ,5℃ 숙성시 15일까지 10^(5) cfu/g으로 감소한 후 증가하여 90일 이후부터 10^(8) cfu/g을 유지하였다. 고염농도에서는 제조직후 10^(5) cfu/g 에서 20℃ 숙성시 4일까지 10^(3) cfu/g으로 감소한 후 증 가하여 10^(4)~10^(5) cfu/g 을 나타냈으며, 5℃ 숙성시 15일까지 급격 히 감소한 후 증가하여 10^(4) cfu/g 을 나타냈다. 3. 20℃ 숙성시 pH는 저염농도에서 제조직후의 pH인 6.8정도를 70일까지 유지한 후 증가하여 7.1~7.2로 변화하였으며, 고염농도에서는 제 조직후의 pH 6.7 정도를 70일까지 유지한 후 감 소하여 6.4를 나타냈다. 5℃ 숙성시에는 식염의 농도와 관계없이 숙성기간 동안 제조직후의 pH 인 6.7~6.8 정도를 큰 변화없이 일정하게 유지하였다. 4. 저염농도에서 산도는 제조직후 182.3mg%이었으나 20℃ 숙성시 계속 감소하여 숙성 120일 경에는 60.0mg%였으며, 5℃ 숙성시에는 계속 증가하여 30 일경에 242.5mg%였다. 고염농도에서 산도는 제조직후 196.7mg%이었으나 숙성 120일 경에는 완만하게 증가하여 5℃숙성시 205.8mg%였으며, 20℃ 숙성시 증가하여 359.1mg%를 나타냈다 . 5. 아미 노태 질소 함량은 저염농도에서 제조직 후 34.4mg%에서 5℃ 숙성시 계속 증가하여 120일경에 174.0mg%였으며, 20℃에서는 숙성 30일경에 405.5mg%로 최고치를 나타낸 후 계속 감소하여 120일경에는 185.9mg%를 나타냈다. 고염농도에서 아미노태 질소 함량은 제조직후 26.6mg%에서 20℃ 숙성시 4일경에 122.3mg%로 급속히 증가하였으며, 숙성 90일 경에는 200℃와 5℃에서 각각 99.9mg%와 136.3mg%로 증가하였다. 6. 저염농도에서 VBN 함량은 제조직후 10.1mg%에서 계속 증가하여 5℃에서는 90일경에 57.6mg%, 20℃에서는 15일경에 68.2mg%로 부패가 시작되었으며, 고염농도에서는 제조직후 8.9mg%에서 완만하게 증가하여 120일 숙성시 온도에 관계없이 각각 14.9mg%와 23.7mg%로 선도가 지속적으로 유지됨을 알 수 있었다. To increase food utilities of freshwater fish, pale chup jeotkal(salted and fermented) was produced by means of dry salting i. e. 8% and 20% by weight. And during the ripening period at 5℃ and 20℃, the changes in the proximate composition, viable cell counts, pH, acidity, amino type nitrogen, volatile basic nitrogen(VBN) and trimethylamine nitrogen(TMA-N) were experimented by fermentation time, concentration of salt and temperature. 1. The proximate composition was not changed so much during the ripening process. The content of moisture, crude protein, crude fat and crude ash in raw pale chup was 74.34%, 13.49 %, 7.06% and 3.1% respectively. In the high salted pale chup the content of moisture, crude protein, crude fat and crude ash was 62.28%, 10.04%, 5.02% and 21.53%. And in the low one, the content of moisture, crude protein, crude fat and crude ash was 71.06%, 11.68%, 5.95% and 10.61 % respectively. 2. Just after the preparation of the low salted concentration, the counts of viable bacterial cell occurred at a level of 10^(6) cfu/g were decreased to a level of 10&^(5) cfu/g by the 4th day of ripening at 20℃ and were increased to 10^(8) cfu/g after the 30th day of ripening and were decreased to 10^(5) cfu/g by the 15th day of ripening at 5℃ and were increased to 10^(8) cfu/g after the 90th day of ripening and the same value was kept. Just after the preparation of the high salted concentration, the counts of viable bacterial cell occurred at a level of 10^(5) cfu/g were decreased to 10^(3) cfu/g by the 4th day of ripening at 20℃ and were increased to 10^(4)∼10^(5) cfu/g. The bacterial counts were decreased rapidly by the 15th day of ripening at 5℃ and were increased to 10^(4) cfu/g. 3. The pH value of ripening at 20℃ in the low salted concentration was kept about 6.8 by the 70th day and was increased to 7.1∼7.2. The pH value of the high salted concentration was kept 6.7 by the 70th day and was decreased to 6.4. The pH value of ripening at 5℃ was kept regularly 6.7∼6.8. 4. Just after the preparation of the low salted concentration, the acidity was 182.3mg% and was decreased to 60.0mg% about the 120th day of a proper ripening period at 20℃ and was increased to 242.5mg % a bout the 30th day of a proper ripening period at 5℃. Just after the preparation of the high salted concentration, the acidity was 196.7mg% and was increased to 205.8mg% about the 120th day of a proper ripening period at 5℃ and was increased to 359.1mg % in a proper ripening period at 20℃. 5. The content of amino type nitrogen was 34.4mg% just after the preparation of the low salted concentration, was increased to 174.0mg% about the 120th day of a proper ripening period at 5℃. It was 405.5mg% about the 30th day of a proper ripening period at 20.C but it was decreased to 185.9mg% about the 120th day. The content of amino type nitrogen was 26.6mg% just after the preparation of the high salted concentration, was increased rapidly to 122.3mg% about the 4th day of a proper ripening period at 20℃ and was increased to 99.9mg%, 136.3mg% about the 90th day of a proper ripening period at 20℃, 5℃ respectively. 6. The content of VBN was 10.lmg% just after the preparation of the low salted concentration. It was increased to 57.6mg% about the 90th day at 5℃, was 68.2mg% about the 15th day at 20℃ and then the samples were spoiled. On the other hand, the content of VBN was 8.9 mg% just after the preparation of the high salted concentration. It was increased slowly to 14.9mg%, 23.7mg% at the 120th day of ripening respectively and the samples were not spoiled.

미생물 성장 특성에 기초한 독립영양탈질의 화학양론식 연구

이수원,김규동,최영균,김동한,정태학 대한상하수도학회 2004 상하수도학회지 Vol.18 No.2

It is necessary to supply external carbon source for enhancement of biological nitrogen removal from domestic wastewater with low influent C/N ratio. Sulfide was chosen as a cost effective electron donor and reaction stoichiometry for autotrophic denitrification was investigated by conducting bench-scale experiments in this study. Higher sulfur to nitrogen (S/N) ratio than the calculated value from theoretical reaction stoichiometry was required when the anoxic reactor was operated at open condition because dissolved oxygen introduced by surface aeration reacted with sulfide with ease. In addition, higher sulfate production and lower yield of microorganism could be observed under the same condition. It was possible to obtain reliable reaction stoichiometry for autotrophic denitrification by establishing pure anoxic condition. Linear relationship between bacterial growth and consumption of nitrate, sulfide, alkalinity, and sulfate production enabled to derive a relatively correct reaction stoichiometry for autotrophic denitrification when sulfide was used as an electron donor.

SiO₂를 이용한 광촉매 TiO₂의 물성 조절

이한수,이호인 한국공업화학회 2003 응용화학 Vol.7 No.2

Nano-sized rutile TiO₂having the particle size of 1 ∼ 5 ㎚ was obtained using MCM-41 and HNO₃as a sizing agent and a crystal structure determining agent, respectively. Due to its small particle size, the prepared TiO₂showed larger bandgap than pure bulk rutile TiO₂. The prepared rutile TiO₂showed higher activity for the photocatalytic oxidation of 2-isopropyl-6-methyl-4-pyrimidinol (IMP) than the bulk rutile TiO₂. A porous anatase TiO₂was prepared without phase transition to rutile over 600℃ through SiO₂incorporation-extraction procedure.

치면세마처치 인식도와 구강위생지수 변화에 대한 연구

이은숙 ; 한만덕 ; 나수정 ; 장종화 김천대학교 2016 김천대학교 논문집 Vol.19 No.-

This study was performed to analyze

메조포어 물질을 이용한 TiO_2의 제조와 광촉매 산화반응에의 적용

이한수,윤봉국,우창수,김소영,He, NongYue,이호인 한국공업화학회 2003 응용화학 Vol.7 No.1

TiO_2-loaded mesoporous materials were prepared by sol-gel method. Mesoporous materials suppressed the phase transformation of TiO_2 from anatase to rutile and increased the bandgap of TiO_2 which was explained in terms of the quantum size effect. Several kinds of nano-sized TiO_2 with particle sizes of 5∼20 nm, were obtained through the removal of the mesoporous materials by etching in 2 M NaOH or the calcination under air condition. They showed good activites in the photocatalytic oxidation of 2-isopropyl-6-methyl-4-pyrimidinol.

A Study on Fire Spread between Office Room and Atrium in the Atrium Building

Lee,Su-Kyung,Kim,Jong-Hoon,Ko,Han-Mog 한국화재소방학회 1997 한국화재소방학회 학술대회 논문집 Vol.1997 No.-

We could analyse the fire behavior using the developed software for fire safety assessment in a large space such as atrium. But Korean building law hasn't admitted the result of fire risk assessment in atrium. In the legislation fire resistant wall or shutter must be required between atrium and office rooms, That has obstructed development of building design and fire protection technique in Korea. From this point of view, we made scenarios of fire spread between atrium and office rooms, and then computed fire spread and fire phenomena using FASTLite and Breakl. In this study, we can decide that fire compartmentalization between atrium and office rooms doesn't require in Atrium building if the material and fire protection system were reliable. Consequently, Korean Fire Protection Regulations have to consider in direction of increasing freedom of building.

학교체육 활성화 방안에 대한 연구(Ⅰ) : 강원대학교 교양체육 운영방법의 개선을 중심으로

이광재,문병용,노성규,박기동,홍관이,한상준,유옥재,엄기진,정청자,오수일,김윤래,박장평,부기원 江原大學校附設 體育科學硏究所 1986 江原大學校附設體育科學硏究所論文集 Vol.- No.11

Try to find a scheme for activation to College Physical Education, this Report informs the various kinds of Survey and process those were projected for improvement of management methods on Cultural Physical Education in Kang Weon National University. From experimentally carried out "Sports events Choosing System" not as usual be inforced "Total practical Skill System", Following Positive effects and sujestions were Presented; 1. "Sports events choosing system" gave birth to more students' interesting and more voluntary participation to the sports events they chose, and sports skill and instruction level was elevated due to charge of expert according to each sports events. This system would be managed continuously hereafter for it related to life sports. 2. This System needs to closed cooperations between College and Community, for the facilities of community are utilized by college. 3. To complete the plan for activation of college Physical Education, additionally, the successional study ; namely "autonomous extracurricular sports activity" should be excuted hereafter.