예측전류제어기를 이용한 3상 PWM 컨버터

한홍일,함년근,성낙규,이승환,이훈구,오봉환,한경희 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

PWM converter has better power factor and low harmonic components than conventional diode rectifiers and phase controlled rectifier. Also the DC link voltage can be regulated fast and stable against the variation in the load. In order to regulate for DC link voltage, rapid current control is need for source current control. This paper focuses on the improvement of quickness of current controller to know the transient state characteristics of regulated DC link voltage against the variation in the load. To do this, it is adopted to three phase voltage type PWM converter with space vector pulse width modulation(SVPWM) method and synchronously rotating d, q axis current. Each d, q axis current is controlled independently. To control d, q axis current, Current control methods to be applied in system are PI current control and Predictive current control respectively. As a result, Transient response characteristic of Predictive current controller is superior to PI current controller.

퍼지알고리즘를 이용한 유도전동기 속도제어에 관한 연구

조정민,전기영,함년근,이승환,이훈구,한경희 명지대학교 대학원 1999 대학원논문집 Vol.3 No.-

The conventional PI controller are fragile in parameter variation and load-variation. Therefore, in this paper, a speed control algorithm based on the Fuzzy PI controller is proposed for the high performance speed control of a voltage ?? inverter to drive 3-phase induction motors. The computer simulation and experiment results show that the proposed controller are more excellent control characteristics than conventional PI controller in transient-state and steady-state response.

미꾸라지 발현백터의 활성도 조사

함경훈(Kyung-Hoon Hahm),임학섭(Hak-Seob Lim),황지연(Jee-Youn Hwang),박진영(Jin-Young Park),김무상(Moo-Sang Kim),이형호(Hyung-Ho Lee) 한국수산과학회 양식분과 1998 韓國養殖學會誌 Vol.11 No.4

미세조류 , Skeletonema costatum 의 성장에 미치는 유기주석 화합물들의 급성 및 만성 독성효과

함경훈(Kyung Hoon Hahm),김무상(Moo Sang Kim),이형호(Hyung Ho Lee) 한국수산과학회 2002 한국수산과학회지 Vol.35 No.5

살충제, 살균제 그리고 antifouling 약품 등으로써의 triorganotin의 사용은 지난 30년간 놀라울 정도로 증가해왔다. 이 보고에서는 미세조류 Skeletonema costatum의 성장에 미치는 여러 triorganotin (TBTO, TBTF, CTPT, TBTC1)들의 급성 및 만성 독성효과를 조사하기 위하여. 단기 및 장기 독성실험을 각각 수행하였다. 단기 독성실험에서, 여러 triorganotin들의 S. costatum에 대한 성장저해 효과는 처리농도에 비례하여 증가하였으며, 이 성장저해는 시간 경과에 따라 회복되었다. 그러나 여러 triorganotin의 독성의 성장저해 효과가 접종한 S. costatum의 세포밀도에 따라 다름을 보였다. 접종 세포농도가 높을수록 triorganotin의 독성효과는 감소하였다. 이러한 결과는 triorganotin의 S. costatum에 의한 분해에 의한 것이라고 판단된다. 장기 독성실험에서는 단기 독성실험에서와는 달리 1㎍/L의 triorganotin의 농도에서도 S. costatum이 사멸하였다. 이러한 사실은 낮은 밀도의 식물성 플랑크톤이 존재하는 해수에서 지속적으로 존재하는 triorganotin의 독성은 훨씬 더 강하게 나타날 수 있음을 보여준다. The use of triorganotins as insecticides, bacteriocides, and antifouling agents has increased dramatically over the past 30 years. In this paper, to evaluate the acute and chronic toxicity effects of various triorganotins (TBTO, TBTF, CTPT, TBTC1) on the growth of microalgae, Skeletonema costatum, we carried out the short term and long term experiments, respectively. In the short-term experiments, the growth of S. costatum was inhibited by the various triorganotins in the dose dependent manners, but recovered by the time laps. The growth inhibition of triorganotins were decreased in the groups with higher initial cell density. These data were resulted from the dilution effect and the biodegradation of triorganotins by the microalgae. In the long-term experiments, S. costatum died completely at the 1 ㎍/L of TBTF and CTPT, but didn`t in short-term experiments. The facts suggest that the toxicity of the chronic exposure of triorganotins should be increased in the natural sea water with low phytoplankton density.

위선암과 병발한 원발성 위 소세포암

박경남,정성훈,이규택,이동후,함준수,이종철,박문향,홍은경,양석철,기춘석,공구 대한내과학회 1990 대한내과학회지 Vol.39 No.5

Primary small cell carcinoma of the stomach has been recognized recently, and only seven well documented examples of this tumor have been reported in the English literature. This tumor is morphologically analogous to its more common pulmonary counterpart and characterized by a very aggressive clinical course. We report a case of concurrent occurrence of adenocarcinoma and primary small cell carcinoma in the stomach, which had a hepatic metastasis of small cell carcinoma. This tumor recealed a positive Grimelius stain, and the patient died 9 weeks after diagnosis. This is the first case of primary small cell carcinoma of the stomach in Korea.

Poster Session 3 / N-10 : Structural studies of cecropin A(1-8)-magainin 2(1-12) , cecropin A(1-8)-melittin(1-12) hybrid peptides and their analogues in DPC micelles using NMR spectroscopy

(Dong Hoon Oh),(Song Yub Shin),(Joo Hyun Kang),(Kyung Soo Hahm),(Kil Lyong Kim),(Yang Mee Kim) 한국생화학분자생물학회 (구 한국생화학회) 1999 생화학분자생물학회 춘계학술발표논문집 Vol.- No.-

상부위장관을 침범한 H-S Purpura 1예

박경남,김지훈,이민호,기춘석,함준수,이종철,박문향,이옥찬,강경원,이동후 대한소화기내시경학회 1992 Clinical Endoscopy Vol.12 No.2

Henoch-Schonlein purpura(anaphylactoid purpura) is a necrotizing vasculitis of small vessels in which systemic manifestation include palpable purpura on the lower extremities and buttocks due to leukocytoclastic vasculitis of dermal vessels; arthralgia of large joints, usually the knees and ankles; gastronitestinal involvement with colic and bleeding; and renal ievolvement, usually with a focal necrotizing glomerulonephritis. Gastrointestinal involvement occurs in about two thirds of all pediatric cases and in about,one third of adult cases, Any bowel segment may be involved, but the jejunum and ileum are most frequently affected. With a brief review of the literature, we report a case of H-S purpura involving stomach and duodenum.

만성 C 형 간염의 조직학적 특징 : 만성 B 형 및 혼합 B , C 형 간염과의 비교 분석

김지훈(Ji Hoon Kim),이오영(Oh Young Lee),주상언(Sang Aun Joo),최호순(Ho Soon Choi),함준수(Joon Soo Hahm),박경남(Kyung Nam Park),기춘석(Choon Suhk Kee),이중달(Jung Dal Lee) 대한내과학회 1994 대한내과학회지 Vol.47 No.4

N/A Objectives: The aims of this study are to compare the differences in histologic findings between chronic hepatitis C (CH-C), mixed chronic hepatitis B and C (CH-B&C) and chronic hepatitis B (CH-B) and to evaluate histopathologic features characteristic of CH-C for diagnostic significance. Methods: Twelve liver needle biopsy specimens from 12 patients with hepatitis C were selected for histologic evaluation. Four specimens of the 12 were not inadequate, and 8 cases were selected for the study. All 8 patients were negative for HBsAg, HRsAb and HBcAb. The specimens were histologically classified as CPH in 5 cases and CAH in 3 cases. Control groups were divided into two. One was CH-B consisted of 20 patients who had negative tests for anti-HCV and positive tests for HBsAg, The 20 CH-B were classified as CAH in 11 cases (CAH-B), and CPH in 9 cases (CPH-B). The other group (CH-B&C) consisted of 14 patients who had positive tests for both anti-HCV and anti-HBs or anti-HBc. Results: 1) Portal inflammation was more frequent in the CH-C group than in the CH-B group (7/8 vs 1/20). However, the difference in portal inflammatory reaction between CH-C and CH-B8rC was not different significantly (7/8 vs 12/14). 2) Piecemeal necrosis was more prominent in the CAH-B group than in the CH-C group (11/11 vs 4/8). 3) Lymphocyte aggregates in the potal tracts were more frequent in the CH-C and CH-B&C (6/8 vs 13/14) than in the CAH-B group (4/11). However, two cases of CH-C and one case of CH-B&C group did not show lymphocyte aggregates in the portal tracts. 4) Bile duct damage and loss of bile duct in the portal tracts were more prominent in the CH-C than in the CH-B (6/8 vs 2/20). However, the difference between CH-C group and CH-B&C was not noted significantly. (6/8 vs 12/14). 5) There was no significant difference in lobular changes such as ballooning degeneration of hepatocytes, focal hepatic necrosis and steatosis between the CH-C and the control (CH-B and CH-B&C group). Conclusion: Portal inflammation with aggregates lymphocytes was more prominent and frequent in the CH-C than in the control (CH-B and CH-B&C). Bile duct damage and/or bile duct loss in portal tracts due to lymphocytes infiltrate were histologic findings chracterisic of CH-C, although not specific for the diagnosis. No significant differences in histologic features of liver needle biopsy specimens between the CH-C and CH-B&C were noted.

위장관 ( 胃腸管 ) : 위암 환자에 있어서 말초혈액 단핵구 및 국소 림프절 단핵구의 NK 및 LAK 활성도에 관한 연구

강진경(Jin Kyung Kang),최흥재(Heung Jai Choi),박인서(In Suh Park),김원호(Won Ho Kim),노성훈(Sung Hoon Noh),함기백(Ki Baik Hahm),김태수(Tae Soo Kim),안신기(Shin Ki Ahn),윤정구(Jung Koo Youn) 대한소화기학회 1991 대한소화기학회지 Vol.23 No.2

N/A Several lymphocytic subpopulations, such as natural killer (NK) cells and lymphokine-activated killer (LAK) cells, are involved in immunosurveillance against tumors. Whereas the biological significance of the regional lymph node as a tumoral barrier remains unclear, the clinical prognostic relevance of the neoplastic infiltration of these nodes is accepted. Although there is general agreement that the NK and LAK activities of peripheral blood mononuclear cells (PBMC) decreases in patients with various solid and leukemic tumors, this decrease remains unclear with regard to the NK and LAK activities of their regional lymph node mononuclear cells (LNMC). We measured NK and LAK activities of PBMC and LNMC in 10 patients with resectable gastric cancer by 4 hour Cr-release assay using K562, Raji cell and allogenous gastric cancer cell as a target cell. The results obtained are as follows: l) Recombinant interleukin-2 induced strong cytotoxic activities against various target cells in PBMC and LNMC. 2) In patients with gastric cancer, NK and LAK activities of LNMC against K56Z and Raji cell were lower than those of PBMC. 3) However, NK ad LAK activities against the allogenous gastric cancer cell did not differ between LNMC and PBMC. 4) NK and LAK activities of PBMC and LNMC against K562 and Raji cell were not different betveen in patient with early gastric cancer and in patients with advanced gastric cancer. 5) However, NK and LAK activities of PBMC ad LNMC against the allogenous gastric cancer cell were lower in patients with advanced gastric cancer than in patients with early gastric cancer.

개의 췌장소도 자가이식 결과에 영향을 미치는 인자들

이상훈,김성주,김병준,오승훈,정인경,양태영,김동준,김광원,이문규,민용기,이명식,정재훈,안규정,함종렬 대한당뇨병학회 2000 Diabetes and Metabolism Journal Vol.24 No.2

Background: Islet cell transplantation is an attractive alternative to whole organ pancreas transplantation, since it is clearly safer and simpler surgical procedure for the recipients. However, several obstacles still remain, because the free islets appear to be more susceptible to non-specific inflammatory damage or immune mediated destruction than islets in an intact pancreas. Therefore, the purpose of this study is to examine the functional outcome of islet autograff and the factors related to the islets graft survival in mongrel dogs. Methods: Twelve adult mongrel dogs weighting 12∼16 kg were used for the experiment of total pancreatectomy and islet autotransplantation. The islets were properly isolated by a modified Recordi method. The obtained islets were further purified by centrifugation on discontinuous gradients using cell separation system (Model 2991, Cobe, Lakewood Colo). After the heparization (50 U/kg), the islets were injected slowly into the liver through the portal vein for 30 minutes. The post-transplantation intravenous glucose tolerence test (IVGTn with glucose disappearance rate (K), liver function test (LFT), fasting plasma glucose (FPG) were measured periodically. Results: 1) The median of Ks were 1.3%min (range 0.3∼2.1) and the IEq/kg (150 m equivalents/kg of recipient body weight) was 3520 (range 1350∼6550). The Ks in recipients with high IEq/kg (≥5,000) were significantly higher than those in recipients with low IEq/kg ($lt;5,000)(r=0.78, p$lt;0.05). 2) The islet cell viability were estimated to be 95% and the median of the required insulin dosage for the maintenance of normal FPG were 0.7 (range 0∼1.6) U/kg/day. The insulin requirement correlated well with the level of IEq/kg (r=0.90, p$lt;0.01). 3) The median of the volume of the transplanted pancreatic islet cell were 2.1 mL (range 0.7∼5.0) and the purity was 60% (range 10∼95). The portal pressure gradients of during the transplant procedure were 4.0 (range 0.5∼12.0) cmH2O. The portal pressure gradients in recipients with high purity were significantly lower than those in recipients with low purity (r=-0.80, p$lt;0.05). Conclusions: In this study, we confirmed that autotransplantation of islet cell on the pancreatectomized dogs can render nearly normogiycemia, and transplanted islet mass was most critical factor to successful autotransplantation in canine model.