구동용 3상 3중 쵸퍼방식

정연택,한경희,이승환,김성남 明知大學校 産業技術硏究所 1987 産業技術硏究所論文集 Vol.6 No.2

This paper, in case of chopper controlling D.C. Motors, suggested three phase chopper system in order to reduce a source current and amature current ripple, and it's characteristic proves study on the theory and experiment. As a result of consideration, it was found that chopper system had reduced current ripple compare with two phase chopper system and impressed voltage of motor could be continuously controlled from 0 to the source voltage by adjusting chopper's time ratio α from 0 to 1.

축우 부루셀라병의 ELISA 진단법에 관한 연구

임윤규,이두식,박전홍,양기천,김승호,김공식,현관종,김우택,이영순 濟州大學校 農科大學 動物科學硏究所 1993 動物科學論叢 Vol.8 No.1

Enzyme-linked Immuno sorbent Assay (ELISA) for the serological diagnosis oi Bruceiia abortus was developed and compared with plate aggluhnation test Cell wall antigen was extracted from Brucella abortus 1119-3 by sonicabon and with a sodium deoxychlate solution Optimum protein concentra tion of coating antigen 0.4㎍/100㎕ protein on each microtiter plate well. Horse radish peroxidase(HRP) labled protein-G was used as a tracer of reacted antibodies ELISA confirmed the agreeable results of 40 rases out of 43 cases by plate aggulutination test ELISA diagnosed positive cases (10 out of 12) and negatiw cases (1 out of 12) with dubious sera by plate agglutination test From this results EL ISA could be used for the early diagnostic tools of Brucellosis in cattle.

n-CdS_(0.46)Se_(0.54)/p-Cu_92-x)S_(0.46)Se_(0.54) 이종접합 태양전지의 제작과 그 특성에 관한 연구

유상하,최승평,이상열,홍광준,서상석,김혜숙,전승룡,윤은희,문종대,신영진,정태수,신현길,김택성,유기수 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

승화방법에 의해 CdS_0.46Se_0.54 단결정을 성장하여 결정구조를 조사하고, Van der Pauw 방법으로 Hall effect를 측정하여 carrier density의 온도 의존성과 mobility의 온도 의존성을 조사하였다. 성장된 CdS_0.46Se_0.54 단결정을 치환반응하여 n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 이종접합 태양전지를 제작하였다. Spectral response, 전류-전압특성 및 전력변환 효율을 조사하여 그 결과로부터 개방전압은 0.48V, 단락 전류 밀도는 21mA/㎠, fill factor와 전력변환효율은 각각 0.75와 9.5%를 얻었다. CdS_0.46Se_0.54 single crystal was grown by a sublimation method. The crystal structure and the temperature dependence of carrier density and mobility of CdS_0.46Se_0.54 single crystal were studied. Heterojunction solar cells on n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 were fabricated by the substitution reaction. The spectral response, the J-U characteristics and the conversion efficiency of the n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells were studied. The open-cricuit voltage, short-circuit density, fill factor and conversion efficiency of n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells under 80mW/㎠ illumination were found to be 0.48V, 21mA/㎠, 0.75 and 9.5%, respectively.

전기자동차 운전을 위한 직류타여자 전동기의 쵸퍼제어

한경희,강승욱,김용주,정연택,이승환 明知大學校 産業技術硏究所 1994 産業技術硏究所論文集 Vol.13 No.-

Recently, the speed control of electric motorcar usually adapts the chopper control method by the development of power electronics and semiconductor manufacturing techniques. When the chooper control is adapted to the speed control of electric motorcar. D.C.series motor is mostly used because of the large starting torques and good control characteristics. But with respect to the economy, D.C. separately excited motor with shunt characteristics is profitable because of high adhesivesness and consumption. So, we compare the characteristics of the bilateral variable-ratio chopper controlled D.C. separately exited motor with that of the D.C. series motor theoretically and experimentally, and present the method which is able to simplify the main chopper circuit by selecting among the forward powering, forward regenerative braking, backward powering, and backward regenerative braking only by using the main chopper control signal. Also, control method is studied which has similar driving characteristics to that of the gasoline motorcar.

Is there any clinical or radiologic feature as a preoperative marker for differentiating mass-forming pancreatitis from early-stage pancreatic adenocarcinoma?

Lee, Hyuk,Lee, Jong Kyun,Kang, Seok Seon,Choi, Dongil,Jang, Kee-Tack,Kim, Jeong Hwan,Lee, Kyu Taek,Paik, Seung Woon,Yoo, Byung Chul,Rhee, Jong Chul G. Thieme 2007 Hepato-gastroenterology Vol.54 No.79

<P>BACKGROUND/AIMS: The differential diagnosis of early-stage pancreatic cancer and mass-forming pancreatitis is still unsettled. The purpose of the present study was to define the differential feature of focal mass-forming pancreatitis and malignant mass using aspects of clinical, laboratory and imaging features on pancreatogram or computed tomography (CT). METHODOLOGY: Between April 1995 and May 2003, 15 patients confirmed as inflammatory mass after surgical resection for pancreatic mass and 21 patients with early-stage pancreatic adenocarcinoma among the patients diagnosed as pancreatic malignancy were included in our study. Hospital records, laboratory results, findings of imaging studies and pathological findings were reviewed retrospectively. RESULTS: Regarding the clinical characteristics, the history of previous pancreatitis was distinguished in group with mass-forming pancreatitis. Incidence of jaundice was higher in the group with adenocarcinoma than in the mass-forming pancreatitis group. For laboratory results, CA19-9 level and alkaline phosphatase level were significantly elevated in the malignant group. Findings such as hyperattenuation on portal venous phase of CT scans and gradual tapering stricture on pancreatogram were differential diagnostic markers between the two groups. A portion of patients with mass-forming pancreatitis demonstrated the pathologic characteristics of autoimmune pancreatitis. CONCLUSIONS: Our 9-year experience suggests that imaging findings such as attenuation pattern on the delayed phase of CT scan and tapering pattern of pancreatic ductal stricture on pancreatogram can help to differentiate mass-forming pancreatitis from early-stage pancreatic adenocarcinoma.</P>

DNA-Base Guanine as Hydrogen Getter and Charge-Trapping Layer Embedded in Oxide Dielectrics for Inorganic and Organic Field-Effect Transistors

Lee, Junyeong,Park, Ji Hoon,Lee, Young Tack,Jeon, Pyo Jin,Lee, Hee Sung,Nam, Seung Hee,Yi, Yeonjin,Lee, Younjoo,Im, Seongil American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.7

<P>DNA-base small molecules of guanine, cytosine, adenine, and thymine construct the DNA double helix structure with hydrogen bonding, and they possess such a variety of intrinsic benefits as natural plentitude, biodegradability, biofunctionality, low cost, and low toxicity. On the basis of these advantages, here, we report on unprecedented useful applications of guanine layer as hydrogen getter and charge trapping layer when it is embedded into a dielectric oxide of n-channel inorganic InGaZnO and p-channel organic heptazole field effect transistors (FETs). The embedded guanine layer much improved the gate stability of inorganic FETs gettering many hydrogen atoms in the gate dielectric layer of FET, and it also played as charge trapping layer to which the voltage pulse-driven charges might be injected from channel, resulting in a threshold voltage (<I>V</I><SUB>th</SUB>) shift of FETs. Such shift state is very ambient-stable and almost irrevocable even under a high electric-field at room temperature. So, Boolean logics are nicely demonstrated by using our FETs with the guanine-embedded dielectric. The original <I>V</I><SUB>th</SUB> is recovered only under high energy blue photons by opposite voltage pulse (charge-ejection), which indicates that our device is also applicable to nonvolatile photo memory.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-7/am405998d/production/images/medium/am-2013-05998d_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am405998d'>ACS Electronic Supporting Info</A></P>

Mutation of K-ras Oncogene in Thyroid Tumor Tissue

Lee, Jai Hak,Lee, Jong Seo,Kim, Seung Nam,Chang, Suk Kyun,Yoo, Seung Jin,Song, Young Tack,Cho, Won Il,Choo, Sang Yong CATHOLIC MEDICAL CENTER 1993 Bulletin of the Clinical Research Institute Vol.21 No.1

Point mutation of oncogene, one of the genetic alteration in cancer development, has been found in many malignant tumor tissues, Among those malignant tumors, the incidence of point mutation of K-ras oncogene was reported over 90% in pancreatic cancers, 40-50% in colotectal cancer, 25-30% in lung cancers and less than 10% in urogenital, breast or cervical cancers. Several investigators have reported the incidence of point mutation of ras oncogene was 30-50% in benign thyroid tumors and 50-80% in malignant thyroid tumors with some difference by tumor cell differentiation. Also some reports suggested ras mutation may constitute early steps in thyroid tumorigenesis. But there if few report about relation between point mutation and characteristics of mutation. In order to find out the incidence of k-ras oncogene point mutation and relation with characteristics of mutation in thyroid tumors, authors isolated DNA from each 10 normal tissue and benign and malignant tumor tissues. And then, point mutations of K-ras oncogene (four characteristics of codon 12 and one characteristic of codon 13) were detected by paired PCR with mutation-specific primer and agarose gel electrophoresis methods. The resets are as follows; 1. Any mutation was not detected in normal thyroid tissues. While point mutations were detected 7/10 cases (70%) of benign thyroid tumor tissues and in 9/10 cases (90%) of malignant tumor tissues. 2. The incidence of GGT-AGT mutation was highest in benign thyroid tumors (60%) and lowest in malignant thyroid tumors (30%). The incidences of GGT-GAT, TGT-GTT and GGC-GAC mutations were high in malignant tumors (60%). 3. There were 8/9 cases (89%) in malignant tumors and 5/7 cases (71%) in benign tumors of positive mutations over two Hinds of mutation. And also 5/9 cases (56%) of malignant tumors and 4/7 case (51%) of benign tumors expressed positive mutations over 3 kinds. Moreover two cases of each benign and malignant turners expressed all of five mutations. With above result, authors proposed that high incidence of point mutation of k-ras oncogene was detected in benign (70%) and malignant (90%) thyroid turners, and especially high incidence of GGT-AGT mutation (60%,) in benign tumors while high incidence of GGT-GAT, TGT, GTT and GGC-GAC mutations(60%) in malignant turners were noted. Also authors suggested that the point mutation may constitute early steps of thyroid tumorigenesis.

PER2 is downregulated by the LPS-induced inflammatory response in synoviocytes in rheumatoid arthritis and is implicated in disease susceptibility

Lee, Hwayoung,Nah, Seong-Su,Chang, Sung-Hae,Kim, Hyung-Ki,Kwon, Jun-Tack,Lee, Sanghyun,Cho, Ik-Hyun,Lee, Sang Won,Kim, Young Ock,Hong, Seung-Jae,Kim, Hak-Jae SPANDIDOS PUBLICATIONS 2017 MOLECULAR MEDICINE REPORTS Vol. No.

<P>The clinical symptoms of rheumatoid arthritis (RA) present with circadian variation, with joint stiffness and pain more prominent in the early morning. The mammalian clock genes, which include circadian locomotor output cycles kaput, brain and muscle Arnt-like protein 1, period and cryptochrome, regulate circadian rhythms. In order to identify the association between genetic polymorphisms in the circadian clock gene period 2 (PER2) and RA, the present study genotyped three PER2 single nucleotide polymorphisms (SNPs), rs934945, rs6754875, and rs2304674, using genetic information from 256 RA patients and 499 control subjects. Primary cultured rheumatoid synovial cells were stimulated with 10 mu M lipopolysaccharide (LPS). Total protein was then extracted from the synovial cells following 12 and 24 h, and PER2 protein expression was assayed by immunoblotting. The rs2304674 SNP demonstrated a significant association with susceptibility to RA following Bonferroni correction. However, statistical analysis indicated that the SNPs were not associated with any clinical features of patients with RA. Immunoblotting analysis demonstrated that PER2 protein expression was decreased by LPS-induced inflammation in RA synovial cells; however, this was not observed in normal synovial cells. The results suggest that the PER2 gene may be a risk factor for RA, and expression of the PER2 protein may be affected by inflammation. Therefore, PER2 may contribute to the pathogenesis of RA.</P>

소형항공기급 인증기 착륙장치 낙하시험

이승규(Seung Gyu Lee),정승택(Seung Tack Jung),양진열(Jin Yeol Yang),김성찬(Sung Chan Kim),안석민(Seok Min Ahn),송정헌(Jung Chen Song) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

A performance of aircraft landing gear is estimated by analysis and verified by drop test. In this paper, a drop test facility is introduced and KC-100 landing gear drop test is presented.

분화된 3T3-L1 세포에서 수세미오이 메탄올 추출물의 지방분해 효과

차승윤(Seung-Youn Cha),장자영(Ja Young Jang),이유현(Yoo-Hyun Lee),이규옥(Gyuok Lee),이호준(Ho Joon Lee),황권택(Kwon-Tack Hwang),김용재(Yongjae Kim),전우진(Woojin Jun),이정민(Jeongmin Lee) 한국식품영양과학회 2010 한국식품영양과학회지 Vol.39 No.6

분화된 3T3-L1 지방세포에서 수세미오이의 메탄올 추출물이 지방의 축적 및 분해에 미치는 영향을 확인하였다. 수세미오이의 메탄올 추출물 안전범위(0~1000 ㎍/mL)에서 지방대사 관련한 여러 과정을 확인한 결과 600 ㎍/mL 이상의 농도에서 세포 내 지방축적이 억제되었고 특히 지방구 내의 triglyceride 함량이 억제되는 것으로 나타났다. 이러한 결과에 대한 기전을 위해 포도당의 유입 억제로 인한 세포 내 triglyceride의 합성감소와 지방분해효소의 활성화로 인한 세포 내 triglyceride의 분해 증가의 두 가지로 확인하였다. 우선적으로 수세미오이의 메탄올 추출물의 포도당 유입 억제 효과를 실험하였지만 아무런 영향이 나타나지 않았다. 하지만 지방분해효소 중 LPL을 제외한 HSL과 ATGL의 유전자 발현이 증가됨에 따라 세포 내 triglyceride이 지방산과 glycerol로 분해되었을 것으로 생각되며 이러한 결과는 세포외로 유리된 glycerol의 함량이 수세미오이의 메탄올 추출물 1000 ㎍/mL의 농도에서 증가한 것을 통해 재확인할 수 있었다. 하지만 600 ㎍/mL의 농도에서 triglyceride 분해는 촉진되었으나 glycerol의 유리가 유의적으로 나타나지 않은 것은 세포 내에서 분해된 glycerol의 일부가 세포 내 생합성에 재사용되었을 것으로 생각되며 실제 세포 외로 유리된 양을 확인하기 위해서는 보다 높은 농도가 필요한 것으로 여겨진다. 전반적으로 본 실험에서는 수세미오이의 메탄올 추출물이 분화된 3T3-L1 지방세포에서 지방구의 생성을 억제하였으나 효과 농도가 다른 많은 천연물에 비해 다소 높게 나타남으로써 제약으로서의 생산으로는 제한점이 있을 것으로 생각되는 반면 식품으로서 꾸준히 사용될 경우 항비만 소재로서의 가능성이 있을 것으로 생각된다. The effect of methanol extract from Luffa cylindrica (LCM) on lipid metabolism and underlying mechanisms of lipolysis in mature 3T3-L1 adipocytes were investigated. The intracellular lipid droplets were stained with Oil Red O dye and quantified. Compared to the control, lipid accumulation was significantly decreased by 19.4% with the treatment of LCM at the concentration of 1000 ㎍/mL. Intracellular triglyceride (TG) level was also reduced by 21% at the concentration of 1000 ㎍/mL. To determine the mechanism for the reduction in TG content, levels of glucose uptake and glycerol release were measured. Incubation of the 3T3-L1 adipocytes with LCM did not affect the cellular uptake of glucose. However, the level of free glycerol released into the cultured medium drastically increased by 24.3% with the treatment of LCM. In subsequent measurements using quantitative real-time PCR, mRNA levels of hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) except lipoprotein lipase (LPL) were significantly elevated at higher concentration. These results suggest that LCM partially stimulates the lipolysis through the induction of HSL and/or ATGL gene expression, resulting in the reduced lipid accumulation and increased glycerol release.