12Cr 강의 화염경화 표면처리 층의 초음속 물방울 충격에 의한 손상 거동

김광호,이민구,김경호,김흥회,김길무 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.1

Water drop impact erosion properties of the 12Cr steel, currently used as nuclear steam turbine blade material, surface-hardened by the flame hardening process have been characterized. For this, variations of both the maximum erosion depth de,,,,ax and volume loss V with the cumulative impacts n at the supersonic impact velocity (~350 m/s) have been investigated for the as-received and flame-hardened 12Cr steels with different hardnesses. Typically all the samples showed an erosion-time characteristic involving the incubation period initially followed by the steady state period. It is also found that the d_(e,max) increases stepwise-like with the number of impacts n, which results from a sudden formation of craters by crack propagation. Compared to those for the as-received 12Cr steel, the flame-hardened ones showed an excellent resistance to water drop impact erosion with 2.2~2.8 times higher incubation time n, and 115~1/8 times lower erosion rate a. In the incubation period the as-received 12Cr steel was damaged by ductile depression and ploughing, while the flame-hardened 12Cr steel by fatigue cracks and brittle platelet deformation. Erosion in the steady state period was developed by the cleavage fracture commonly. (Received July 22, 2004)

관동맥 우회로술 중 경식도 심초음파도로 관찰한 도부타민 투여후와 우회로술후의 좌심실 국소벽운동

김희열,김종진,윤호중,유기동,박지원,이길환,노태호,채장성,김재형,홍순조,최규보 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.8

Effects of Herbal Extracts Used in Oriental Medicines on Heme Oxygenase-1 Expression

Jeong, Gil-Saeng,Oh, Seung-Hwan,Kang, Dae-Gill,Lee, Ho-Sub,Kim, Youn-Chul The Physiological Society of Korean Medicine and T 2006 동의생리병리학회지 Vol.20 No.5

Effects of twenty-three aqueous herbal extracts used in oriental medicines on heme oxygenase (HO)-1 expression were estimated in a mouse hippocampal cell line, HT22. HO-1 is one of the cytoprotective enzymes activated various stimuli, and Western blot analysis was used for evaluated HO-1 expression. Six aqueous extracts such as Rhei Rhizoma, Paeoniae Radix, Uncariae Ramulus et Uncus, Theae Folium, Prunellae Spica, and Coptidis Rhizoma significantly increased HO-1 expression in HT22 cells at the concentration of 300 ${\mu}$g/ml. In Addition, four aqueous extracts including Eucommiae Cortex, Moutan Cortex Radicis, Ginseng Radix Rubra, and Scutellariae Radix moderately increased HO-1 expression. These results would be usefulfor the isolation and identification of their neuroprotective principles.

Sauchinone Suppresses Pro-inflammatory Mediators by Inducing Heme Oxygenase-1 in RAW264.7 Macrophages

Li, Bin,Lee, Dong-Sung,Choi, Hyun-Gyu,Kim, Kyoung-Su,Kang, Dae-Gil,Lee, Ho-Sub,Jeong, Gil-Saeng,Kim, Youn-Chul Pharmaceutical Society of Japan 2011 BIOLOGICAL & PHARMACEUTICAL BULLETIN Vol.34 No.10

<P>Sauchinone, a biologically active lignan isolated from the roots of <I>Saururus chinensis</I> (L<SMALL>OUR</SMALL>.) B<SMALL>AILL</SMALL>. (Saururaceae), is reported to exert a variety of biological activities, such as hepatoprotective, anti-inflammatory actions and inhibitory effects on bone resorption. In this study, we investigated the effect of sauchinone in suppressing cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, leading to a reduction in COX-2-derived prostaglandin E<SUB>2</SUB> (PGE<SUB>2</SUB>) and iNOS-derived nitric oxide (NO) production in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages. Present study also demonstrates the effects of sauchinone in inducing heme oxygenase-1 (HO-1) expression and an increase in heme oxygenase (HO) activity in RAW264.7 macrophages. The effects of sauchinone on LPS-induced PGE<SUB>2</SUB>, NO, tumor necrosis factor-α (TNF-α) and interlukine-1β (IL-1β) production were partially reversed by the HO-1 inhibitor Tin protoporphyrin was also seen in this study. In addition, we found that treatment with extracellular signal-regulated kinase (ERK) inhibitor (PD98059) reduced sauchinone-induced HO-1 expression. Sauchinone also increased ERK phosphorylation. These results suggest that sauchinone inhibits pro-inflammatory mediators through expression of anti-inflammatory HO-1 <I>via</I> ERK pathway.</P>

정신분열병과 N-Methyl-D-Aspartate 수용체 유전자와 연관된 VNTR 표지자인 D9S158 다형성의 연합

김종원,채영규,정은기,김길숙,박강규,이영호,최인근,양병환,한진희 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.5

정신분열병과 NMDA 수용체와 연관된 D9S158 유전적 표지자와의 연관성을 알아보기 위해 75명의 정신분열병 환자군과 87명의 정상대조군을 대상으로 중합효소연쇄반응을 이용하여 연합연구를 시행하여 다음과 같은 결론을 얻었다. D9S158 유전좌위에는 모두 8개의 대립유전자가 있었고, 각 대립유전자는 cytosine-adenine염기가 반복되는 217염기쌍에서 233염기쌍의 형태였다. 먼저 정신분열병 환자와 정상대조군의 대립유전자의 빈도를 비교해 본 결과 통계적으로 유의한 차이를 보이지 않았다(p〉.05). 환자군을 좀 더 동질적으로 만들기 위해 정신분열병의 가족력 유무, 음성 및 양성증상, 연성신경학적 징후, DSM-IV 임상아형에 따라 환자군을 나누어 대립유전자의 빈도를 비교해 본 결과, 특정 임상양상과 관련이 있는 대립유전자를 발견하지 못하였다. 결론적으로 본 연구에서는 D9S158 유전좌위와 정신분열병의 연관성을 입증하지 못하였으나 NMDA 수용체 유전자주위의 다른 표지자나 좀 더 유전적으로 동질한 환자군을 대상으로 한 추후연구가 필요할 것으로 생각된다. An association study with Korean schizophrenic patients(N=75) and normal controls(N=87) was performed to find the relationship between D9S158 polymorphism and schizophrenia using polymerase chain reaction. Eight different alleles of a dinucleotide polymorphism on D9S158 locus were observed in both group. When we compared the frequencies of alleles between schizophrenics and normal controls, there was no significant difference between two groups. To increase homogeneity of schizophrenic group, we divided schizophrenic group by clinical phenotypes such as family history, negative and positive symptoms(PANSS), soft neurologic signs(NES-K) and DSM-IV diagnostic subtypes. Then we compared the frequencies of alleles among subgroups of clinical phenotypes, and there were no significant differences between subgroups(p〉.05). Although our findings fail to provide an evidence of association between schizophrenia and D9S158 locus, further investigation of other loci that are linked to NMDA receptor gene may be needed in genetically homogeneous subgroups of schizophrenia.

음낭외상시 초음파 촬영술의 유용성

김형지,진정환,이해원,이길호 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Testicular rupture is a surgical emergency which command immediate repair. If surgery is delayd, a hematoma causes severe pain and loss of spermatogenesis as well as hormonal functions. Scrotal ultrasonography has been helpful in early diagnosis of testicular rupture. But disadvantage of ultrasonography include a relatively low signal-to-noise level, tissue nonspecificity, lack of contrast media, a small field of view, and dependence on the operators skill and the patients physique. Also the diagnostic accuracy, sensitivity or specificity of scrotal ultrasonography was variable in regard to authors. And so, a diagnostic accuracy of scrotal ultrasonography was evaluated in scrotal trauma. Methods·. We reviewed 38 patients of scrotal trauma from May, 1994 to March, 1998. 6 patients were treated conservatively fellowing sonography and 10 patients treated only surgical exploration without ultasonography Surgical exploration was performed in 22 case, which were evaluated by ultasound before surgical treatment. In a such 22 cases, diagnostic accuracy of scrotal ultasonography was evaluated. Results: We compared ultrasound before treatment with surgical exploration finding in a such 22 cases. The ultrasonographic features in 7(31.8%) out of 22 cases, which showed testicular ruptured, but surgical exploration revealed testicular rupture in5 and epididymal rupture in 1, simple hematocele in 1. In 15(68.2%) out of 22cases the simple hematocele was diagnosed by ultrasonography, but surgical finding feature in of the 7 cases revealed testicular rupture, epididymal rupture in 1, simple hematocele in 7. The sensitivity and specificity for the ultrasonography are 42.9% and 87.5%, and the positive and negative predictive values are 86.5%and 46.7%, respectively. Ultrasonography is low sensitive in identifying testicular rupture. Conclusion: 7trasonography include a relatively low signal-to-noise level, tissue nonspecificity, lack of contrast media, a small field of view, and dependence on the operators skill and the patients physique. Therefore, early surgical exploration for saving the testis should be performed that sonographically by seeing hypoehoic peripheral lesions and disappearance of normal ovoid form of testis, hematocele in scrotal sac.

Diode Laser의 주입전류에 의한 진동수 변조

김필수,김길호 漢陽大學校 基礎科學硏究所 1993 基礎科學論文集 Vol.12 No.-

다이오우드레이저의 특성과 주입전류에 의한 진동수 변조에 관하여 연구하였다. 사용한 반도체 레이저의 발광소자는 SHARP사의 GaAlAs계의 LTO22MC형 레이저 다이오우드로 실온에서 출력 5mW, 피크파장 780nm를 가진다. 레이저 다이오우드의 주입전류를 일정하게 유지하고 온도를 -15℃ 에서 15℃까지 변화시켰을때의 방출피크파장은 계단적으로 증가하였고 파장변화폭은 약 6nm정도로서 파장의 온도 의존도는 0.2nm/℃이었다. 다음에 온도를 일정하게 유지하고 주입전류를 45mA에서 78mA까지 변화시켰을 때에도 방출피크파장 역시 계단적인 변화 양상을 보였으며 변화폭은 약 3nm으로 파장의 전류의존도는 0.10nm/mA였다. 다이오우드 레이저의 문턱전류는 온도가 감소함에 따라 낮아지지만 방출광의 강도는 증가하였다. 특히 공초점공진기와 주입전류에 의한 다이오우드 레이저의 진동수변조가 가능하였다. This study deals with the characteristics of a diode laser and it's frequency modulation by injection current. The used laser diode is Sharp's GaAlAs type LTO22MC with output power of 5mW and peak wavelength of 780nm at room temperature. The output peak wavelength from the diode laser increases stepwise with increasing temperature from -15℃ to 15℃, giving a wavelength dependence of 0.2nm/℃ with a tunable range of 6nm at fixed current. The output waelength also varies stepwise in the injection current ranging from 45mA to 75mA with a tunablity of 3nm and a current dependence of 0.10nm/mA. It is found that the threshold current of the diode laser increases with decreasing temperature at fixed current. In this case the output power rather increases. It is noticed that the output power frequency can be modulated by injection current of the diode laser through a confocal resonant cavity of r=50mm.

Cyclosporin A의 肝毒性에 미치는 右歸飮의 影響

金昊顯,申興默,金吉萱 동국대학교 한의학연구소 1993 東國韓醫學硏究所論文集 Vol.2 No.2

The purpose of this study is to observe the effect of Woogyuyem on serum reaction and hepatic tissue in Cyclosporin A treated rats. In this study, the experimental rats divided two group(Contro1 group and Sample group). Under the Same condition, both control group and sample group were injected to abdomen with Cyclosporin A for 7days. And then, control group were administered water, sample group were administered Woogy-uyeum for 30days. The change of transaminase and bile acid and SOD activity in blood serum, hepatic tissue were measured at 3rd, 7th, 15th, 30th day. The obtained results are surnmarised as follows : 1. In the change of SGOT contents, as compared with control group, sample group was significantly decreased at 7th and 15th day. 2. In the change of SGPT contents, as compared with control group, sample group was signi�icantly decreased at 15th day. 3. In the change of serum bile acid contents, as compared with control group, sample group was significantly decreased at 7th and 15th day. 4. In the change of serum SOD activity, as compared with control group, sample group was significantly increased at 15th and 30th day. 5. In the change of hepatic tissue, as compared with control group, the vacuolation of hepatocytes in the sample group was reduced, the liver plates were reconstructed, and the epitherial cell wasn't destructed.

모바일 로봇의 견실제어를 위한 제네틱 알고리즘 개발

김홍래,배길호,정경규,한성현 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

This paper proposed trajectory tracking control of mobile robot. Trajectory tracking control scheme are real coding genetic-algorithm and back-propergation algorithm. Control scheme ability experience proposed simulation. Stable tracking control problem of mobile robots have been studied in recent years. These studies have guaranteed stability of controller, but the performance of transient state has not been guaranteed. In some situations, constant gain controller shows overshoots and oscillations. So we introduce better control scheme using Real coding Genetic Algorithm(RCGA) and neural network. Using RCGA, we can find proper gains in several situations and these gains are generalized by neural network. The generalization power of neural network will give proper gain in untrained situation. Performance of proposed controller will verify numerical simulations and the results show better performance than constant gain controller.

자기구성 퍼지 제어기법에 의한 수직다관절(AMI)로봇의 위치 및 속도 제어

김종수,배길호,한성현 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

본 연구에서는 산업용 로봇 시스템의 정밀도 및 견실성을 향상시키기 위하여 자기구성 퍼지제어 알고리즘을 개발하여 디지털 신호 처리기에 기초한 관절제어기를 설계하고 이의 실시간 제어실현에 대한 연구가 수행되었다. 제안된 자기구성 퍼지 제어기는 적절한 제어입력을 출력하면서 환경을 관측하고 이 제어입력으로 인한 결과를 이용하여 다음에 나올 결과를 향상시킨다. 그러므로 자기구성 퍼지 제어기를 이용하면 환경에 대한 최소의 정보만을 가지고도 견실 제어기를 설계할 수 있다. 본 논문에서는 조정인자와 규칙을 동시에 수정하여 제어규칙이 점근적으로 수렴하면서 수렴속도를 향상시킬 수 있는 자기구성 퍼지 제어기를 제안하였다. 제안된 자기구성 퍼지 제어기는 위에서 언급한 바와 같이 퍼지 제어기의 단점을 보완하는 측면이 있기 때문에 성능향상을 기대할 수 있다. 따라서, 본 논문에서는 퍼지추론기능과 퍼지규칙 조정능력을 갖는 퍼지 알고리즘을 개발하고 외부환경의 변화 즉, 제어대상인 플랜트의 파라미터변화 및 부하의 변동에 대해서도 능동적이고 우수한 제어성능이 유지될 수 있는 고정도 산업용 로봇 제어기 설계기법을 제안하고, 수직다관절(AM1)로봇에 대한 시뮬레이션 및 실험을 통해 그 성능을 검증하였다. In this paper, it is presented a new technique to the design and real-time implementation of fuzzy control system based-on digital signal processors in order to improve the precision and robustness for system of industrial robot. Fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the real of industrial processes. In this thesis, a self-organizing fuzzy controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variable of the controller, In the synthesis of a FLC, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult, SOFC is proposed for a hierarchical control structure consisting of basic level and high level that modify control rules.