Discrimination of Insulation Defects in a Gas Insulated Switchgear (GIS) by use of a Neural Network Based on a Chaos Analysis of Partial Discharge (CAPD)

Seoung-Yong Jung,Cheol-Hwi Ryu,Yun-Sok Lim,Ja-Ho Lee,Ja-Yoon Koo 대한전기학회 2007 Journal of Electrical Engineering & Technology Vol.2 No.1

In this work, experimental investigation is carried out in order to design and fabricate the UHF sensor that is able to detect the partial discharges produced from 10 artificial defects introduced into the real scale 70㎸ GIS mock-up under high voltage within a well shielded room. As well, in order to verify the on-site applicability of our method, the newly proposed CAPD (chaos analysis of partial discharge) is combined with spectral analysis for identifying the nature of 10 artificial defects under investigation. The PD pattern recognition of each defect has been fulfilled by applying our ANN software. The result indicates that the recognition rate reaches up to 80% by the newly proposed method while the traditional PRPD analysis method allows us to obtain 41%. In consequence, it can be pointed out that the proposed method seems likely to be applicable to the real GIS at the site.

Hydrogenated Amorphous Silicon Gate Driver Made of Thin-Film Transistors

Ja Hun Koo,Jin Jang,Eung Bum Kim,H. Uchiike,Jae Won Choi,Moon Hyo Kang,S.W. Lee,Se Hwan Kim,Young Seoung Kim 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.4

We developed a hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) gate driver having a long operation. The gate driver, composed of 9 a-Si:H TFTs including two pull-down transistors and one capacitor, was demonstrated in the present work. The pull-down transistors, under an AC bias during operation, prevent the floating of the gate line. The bias-stress effect of the fabricated a-Si:H TFTs was studied with various bias conditions to study the lifetime. The simulation results based on the experimental results indicate that the lifetime of the proposed a-Si:H gate driver can be over 5 years.

Intermedeol Isolated from the Leaves of Ligularia fischeri var. spiciformis Induces the Differentiation of Human Acute Promyeocytic Leukemia HL-60 Cells

Jeong, Seoung-Hee,Koo, Seung-Ja,Choi, Jung-Hye,Park, Jae-Hoon,Ha, Joohun,Park, Hee-Juhn,Lee, Kyung-Tae WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2002 東西醫學硏究所 論文集 Vol.2002 No.-

The present work was performed to investigate the effects of intermedeol on proliferation and differentiation of human leukemia-derived HL-60 cells as well at the underlying mechanisms for these effects. Intermedeol exhibited a potent antiproliferatlve activity against HL-60 cells. In addition. this compound was found to be a potent inducer for HL-60 cell differentiation as assessed by nitroblue tetrazolium reduction test, esterase activity assay, phagocytic activity assay, morphology change, and expression of CDl4 and CD66b surface antigens. These results suggest that intermedeol induces differentiation of human leukemia cells to granulocytes and monocytes/macrophage lineage. Moreover, the expression level of c-myc was down-regulated during intermedeol-dependent HL-60 cell differentiation. whereas p21^CIPI was up-regulated. Taken together, our results suggest that intermedeol may have potential as a therapeutic agent in human leukemia.

인터넷에서의 공정성 향상을 위한 새로운 큐 관리 알고리즘

구자헌(Ja-Hon Koo),정광수(Kwang-Sue Chung),오승준(Seoung-Jun Oh) 한국통신학회 2003 한국통신학회 학술대회 및 강연회 Vol.2003 No.4

위에 발생한 원발성 소세포암

김성훈,김지연,김현영,신채희,김동완,김기환,박현용,박무인,박선자,구자영 고신대학교 의학부 2002 高神大學校 醫學部 論文集 Vol.17 No.1

Primary small cell carcinoma of the stomach is a very rare cell type in gastric cancer and an extremely aggressive tumor with grave prognosis. Because of the highly malignant potency, chemotherapy for the primary therapy of small cell carcinoma is accepted generally. We report a 44-year-old man with primary advanced gastric small cell carcinoma who respond to cisplatin and etoposide combination chemotherapy.

Discrimination of Insulation Defects in a Gas Insulated Switchgear (GIS) by use of a Neural Network Based on a Chaos Analysis of Partial Discharge (CAPD)

Jung, Seoung-Yong,Ryu, Cheol-Hwi,Lim, Yun-Sok,Lee, Ja-Ho,Koo, Ja-Yoon The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.1

In this work, experimental investigation is carried out in order to design and fabricate the UHF sensor that is able to detect the partial discharges produced from 10 artificial defects introduced into the real scale 70kV GIS mock-up under high voltage within a well shielded room. As well, in order to verify the on-site applicability of our method, the newly proposed CAPD (chaos analysis of partial discharge) is combined with spectral analysis for identifying the nature of 10 artificial defects under investigation. The PD pattern recognition of each defect has been fulfilled by applying our ANN software. The result indicates that the recognition rate reaches up to 80% by the newly proposed method while the traditional PRPD analysis method allows us to obtain 41%. In consequence, it can be pointed out that the proposed method seems likely to be applicable to the real GIS at the site.

Induction of Apoptosis by Yomogin in Human Promyelocytic Leukemic HL-60 Cells

JEONG, Seoung-Hee,KOO, Sung-Ja,HA, Joo-Hun,RYU, Shi-Yong,PARK, Hee-Juhn,LEE, Kyung-Tae WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2004 東西醫學硏究所 論文集 Vol.2004 No.-

Yomogin is an active compound isolated from Artemisia princep, a traditional Oriental medicinal herb, which has been shown to inhibit tumor cell proliferation. In this study, we investigated the effects of yomogin on the cytotoxicity, induction of apoptosis, and putative pathways of its actions in human promyelocytic leukemia cells. Yomogin-treated HL-60 cells displayed several features of apoptosis, including DNA fragmentation, formation of DNA ladders in agarose gel electrophoresis, and externalization of annexin-V targeted phosphatidylserine residues. We observed that yomogin caused activation of caspase-8, caspase-9, and caspase-3. A general caspase inhibitor (z-VAD-fmk), caspase-8 inhibitor (z-IETD-fmk) and caspase-3 inhibitor (z-DEVD-fmk), almost completely suppressed the yomogin-induced DNA fragmentation. We further demonstrated that yomogin induced Bid cleavage, mitochondrial translocation of Bax from the cytosol, and cytochrome c release from mitochondria in a caspase-8-dependent manner. Taken together, our data indicate that yomogin is a potent inducer of apoptosis and facilitates its activity via caspase-8 activation, Bid cleavage, Bax translocation to mitochondria, and subsequent release of cytochrome c into the cytoplasm, providing a potential mechanism for the anticancer activity of yomogin.

藻類培養을 利用한 二次 處理水의 營養物質除去에 관한 硏究

이희자,안승구 서울市立大學校 1992 論文集 Vol.26 No.-

This paper describes the working of algal culture system under batch and continuous feeding effluents in biological treatment process. The main objective of this study was the determination of fundamental operating parameters such as dilution rates, light intensity, biomass concentration, nutrients contents, which engender an effective nutrient and organic waste removal process. The results of this research indicate that the algae culture system will be an effective nutrient and organic waste removal device. In batch culture, 91.8% dissolved orthophosphate and 83.3% ammonia nitrogen were removed from the sewage in ten days. In continuous flow systems, a detention time of 2.5 days was found adequate to remove 91% T-P, 87% T-N and 95% NH3-N. At 22-28℃, 60rpm, with an intensity of 3,500Lux, the specific growth rate was k=0.59/day in batch experiments. The optimal growth temperature and nutrients ratio(N/P) were 25℃ and 3-5.

메탄산화균의 혼합배양에 의한 질소제거 특성연구

이희자(Hee Ja Lee),안승구(Seoung Koo Ahn) 한국물환경학회 1999 한국물환경학회지 Vol.15 No.2

In this study, methane-oxidizing bacteria were isolated from a landfill cover soil and cultured in inorganic nutrient medium with methane as a carbon and energy source. The methane oxidation rate on O₂/CH₄ ratio and other important factors affecting the growth of methanotrophs were evaluated by batch cultures. Also, the possibility of aerobic denitrification by mixed culture of methanotrophs, NH₃ and NO₃^- removal rate on nitrogen concentration were investigated. The results of the study showed that methane-oxidizing bacteria were short rod and gram negative, and formed pink colonies. The settleability of the sludge was very good When O₂/CH₄ volume ratio were 1.8, 2.2 and 5.4, methane was oxidized in a first-order reaction with respect to the concentration of methane and rate coefficients of the reactions were 0.7, 0.9 and 1.1, methane was oxidized in a second-order reaction. Methanotrophs could tolerate pH fluctuations of influent, and the maximum denitrification rate and cell yield at pH 7.5 was 16.4㎎ NO₃^- -N/g VSS·hr and 12.2㎏ VSS/㎏ NO₃^- -N, respectively. The maximum specific growth rate of the methanotrophs was 0.3/day at 30℃, and the maximum denitrification rate was 35㎎ NO₃^- -N/g VSS·hr at 35℃. At a Cu variation of 0-30ppm, the growth rate of methanotrophs was highest at 1ppm. At an O₂/CH₄ volume ratio of 1.3, at which the growth rate was highest, and the maximum denitrification rate was 45㎎ NO₃^- -N/g VSS·hr. In the aerobic condition with DO concentration of 1.2㎎/L, denitrification rate was increased in porportion to nitrate concentration, Vmax and Ks were 3.5㎎ NO₃^- -N/g VSS·hr, 145㎎ NO₃-N/L, respectively.

인체위암세포주(AGC)의 증식에 미치는 lovastatin의 억제효과

김지연,김성훈,서수홍,최병주,김현영,노치환,김동완,김기환,박무인,구자영 고신대학교 의학부 2002 高神大學校 醫學部 論文集 Vol.17 No.1

Background At the first step of cholesterol synthesis, 3-hydroxy-3-methylglutaryl-CoA reductase(HMG-CoA reductase) catalyzes the formation of mevalonate, which is the precusor of isoprenoid moieties that are incorporated into or linked to several molecules for cell growth and replication, which include Ras, Rho, G proteins and nuclear laminin B. Lovastatin(mevinolin), as an inhibitor of HMG-CoA reductase, blocks mevalonate synthesis, by which also prevents the isoprenylation of several proteins such as Ras, display antitumor effect in experimental models. In the present study the effects of lovastatin on the growth of human gastric carcinoma cell line, AGS cells were examined and the effects of 5-fluorouracil(5-FU) were also studied. Cell cycle analysis was done to examine the mechanisms for the inhibitory effects of lovastatin. Methods The growth of AGS cells were examined by counting cell number on one and three days treatment with 0.2umol/L, 0.4umol/L, 0.8umol/L, 1.6umol/L, 3.2umol/L lovastatin, and 0.1umol/L, 0.3㎍/㎖ 5-FU, after plating AGS cells into 35㎚^(2) plastic dishes at a density of 10*10^(4) cells/dish. The reversibility of the effects of lovastatin was examined on one day to seven days treatment with 0.8u㏖/L lovastatin after seeding 10*10^(4) cells/dish. To examine the mechanisms for the inhibitory effects of lovastatin, cell cycle analysis was done on the cells after four days treatment with 0.8u㏖/L lovastatin. Results Lovastatin significantly inhibited the growth of AGS cells in a dose-dependent fashion(p<0.05). Forth-eight percent inhibition of growth was found at an lovastatin concentration of 0.8umol/L and ninety-three percent inhibition of growth was found at an lovastatin concentration of 3.2umol/L after 4 days treatment. The inhibitory effect of lovastatin on the growth of AGS cells was firstly shown at the concentration of 0.4umol/L. The removal of lovastatin by a media change after 24 hours treatment of lovastatin was note different from that of control group, which was not treated by lovastatin. Lovastatin combined with 5-FU significantly inhibited the growth of AGS cells in a dose-dependent fasion compared to lovastatin or 5-FU alone(p<0.05), which suggested additive effect of the two drugs. After four days treatment with 0.8umol/L lovastatin, the fraction of cells in G0-G1 phase, S phase and G2-M phase was 51.5%, 31.5%, 17.0% respectively in the control group, and 50.6%, 32.6%, 16.7% in the lovastatin group(0.8umol/L), showing no significant differences between the two. Conclusions Lovastatin significantly inhibited the growth of AGS cells in a dose-dependent fashion, The inhibitory effect for lovastatin on the growth of AGS cells was reversible since the growth of AGS cells after removal of lovastatin by a media change after 24-48hours treatment of lovastatin was note different from that of control group which was note treated by lovastatin. The reversibility of growth inhibition suggests that lovastatin is not a non-specific cytotoxin for AGS cells. This is the first report that lovastatin may be very useful for the treatment of gastric carcinoma, especially in conjunction with 5-FU, because the concentrations(0.2-3.2umol/L) used in our study were within the ranges of steady-state concentrations(0.15-0.3umol/L) attainable in human serum by chronic administration of maximum recommended dose(80/㎎/day) of lovastatin and additive effect of lovastatin and 5-FU. More studies by animal experiments and clinical trials are needed to establish lovastatin as an anticancer drug for human gastric carcinoma.