최적 연료주입 모델 추종형 ${\mu}-$합성 제어기의 설계에 관한 연구

황현준,김동완,정호성,손무헌,김영훈,황기현,문경준,박준호,황창선,Hwang, Hyun-Joon,Kim, Dong-Wan,Jeong, Ho-Seong,Son, Mu-Hun,Kim, Yeung-Hun,Hwang, Gi-Hyun,Mun, Kyeong-Jun,Park, June-ho,Hwang, Chang-Sun 제어·로봇·시스템학회 1998 제어·로봇·시스템학회 논문지 Vol.4 No.2

In this paper, we design an optimal model following ${\mu}-$synthesis control system for fuel-injection of diesel engine which has robust performance and satisfactory command tracking performance in spite of uncertainties of the system. To do this, we give gain and dynamics parameters to the weighting functions and apply genetic algorithm with reference model to the optimal determination of the weighting functions that are given by the D-K iteration method which can design ${\mu}-$synthesis controller in the state space. These weighting functions are optimized simultaneously in the search domain which guarantees the robust performance of the system. The ${\mu}-$synthesis control system for fuel-injection designed by the above method has not only the robust performance but also a better command tracking performance than those of the ${\mu}-$synthesis control system designed by trial-and-error method. The effectiveness of this ${\mu}-$synthesis control system for fuel-injection is verified by computer simulation.

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)

Nicotine Detoxification of Rutin, Quercitrin, and Chlorogenic Acid Isolated from Houttuynia cordata by Reducing Reactive Oxygen Species and Inducing Conversion from Nicotine to Cotinine

Kim, Kyeong Mu,Shim, Soon-Mi The Korean Society for Applied Biological Chemistr 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.4

The hypothesis of the present study is that methanol extract of Houttuynia cordata Thunb (MEH) and its targeted bioactive components including rutin, quercitrin, and chlorogenic acid can be effective in reducing reactive oxygen species (ROS) caused by nicotine and promoting nicotine to cotinine in HepG2 cell. Oxygen radical absorbance capacity (ORAC) of bioactive components and MEH was measured to assess free radical scavenging capacity. ROS inhibition ability of bioactive components and MEH was measured by 2',7'-dichlorodihydrofluorescein diacetate assay. The conversion rate of nicotine to cotinine by bioactive components and MEH was determined by the direct barbiturate assay method. ORAC value confirmed that MEH and its bioactive components provided an antioxidant capacity ranging from 126 to $138{\mu}M$ trolox equivalents/100 g. Compared to nicotine only, pretreatment of MEH, rutin, and quercitrin was revealed to effectively inhibit ROS production in HepG2 cell by up to 9, 7.4, and 14%, respectively. Nicotine conversion to cotinine after 120 min incubation was 1.7 and 1.4 times higher in rutin and chlorogenic acid pretreatment than the control, respectively. H. cordata and its targeted bioactive components could be a valuable natural ingredient for inhibiting ROS formation by nicotine as well as enhancing the rate of nicotine to cotinine turnover.

Curcumin ameliorates cadmium-induced nephrotoxicity in Sprague-Dawley rats

Kim, Kyeong Seok,Lim, Hyun-Jung,Lim, Jong Seung,Son, Ji Yeon,Lee, Jaewon,Lee, Byung Mu,Chang, Seung-Cheol,Kim, Hyung Sik Elsevier 2018 Food and chemical toxicology Vol.114 No.-

<P><B>Abstract</B></P> <P>Chronic exposure to cadmium (Cd) causes remarkable damage to the kidneys, a target organ of accumulated Cd after oral administration. The aim of the present study was to investigate the protective effect of curcumin against Cd-induced nephrotoxicity. Sprague–Dawley male rats were divided into the following four treatment groups: control, curcumin (50 mg/kg, oral), CdCl<SUB>2</SUB>, (25 mg/kg, oral), and pre-treatment with curcumin (50 mg/kg) 1 h prior to the administration of CdCl<SUB>2</SUB> (25 mg/kg, oral) for 7 days. At 24 h after the final treatment, the animals were killed, and the biomarkers associated with nephrotoxicity were measured. Our data indicated that blood urea nitrogen (BUN) and serum creatinine (sCr) levels were significantly reduced by curcumin pre-treatment in CdCl<SUB>2</SUB>-treated animals. Histopathological studies showed hydropic swelling and hypertrophy of the proximal tubular cells in the renal cortex after Cd treatment. Pretreatment with curcumin ameliorated the histological alterations induced by Cd. The urinary excretion of kidney injury molecule-1 (Kim-1), osteopontin (OPN), tissue inhibitor of metalloproteinases 1 (TIMP-1), neutrophil gelatinase-associated lipocalin (NGAL), and netrin-1 significantly reduced by curcumin treatment compared to that in the CdCl<SUB>2</SUB>-treated group. The administration of curcumin provided a significant protective effect against Cd-induced nephrotoxicity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Curcumin protects against cadmium-induced renal injury. </LI> <LI> Curcumin reduces urinary excretion of AKI biomarkers. </LI> <LI> Curcumin protects against cadmium-induced apoptosis in the kidney. </LI> </UL> </P>

전남 가거도의 식물상

윤경원 ( Kyeong Won Yun ),황용 ( Yong Hwang ),소순구 ( Soon Ku So ),김무열 ( Mu Yeol Kim ) 한국환경생태학회 2012 한국환경생태학회지 Vol.26 No.2

가거도는 전남 신안군 흑산면에 속하는 한국의 최서남단에 위치한 섬이다. 가거도의 관속식물은 93과 246속 289종7아종 36변종 9품종으로 총 341분류군으로 조사되었다. 열매가 노란색인 참식나무의 새로운 품종이 발견되어 노랑참식나무 Neolitsea sericea (Bl.) Koidz. for. koreana M. Kim 라고 명명하였다. 가거도의 특산식물은 흑산도비비추, 처진물봉선, 새끼노루귀, 개족도리풀 등 8종이 발견되었으며, 희귀 및 멸종위기식물은 박달목서와 으름난초 등 3종이 발견되었다. 식물지리학적으로 흥미있는 종은 푸른가막살, 가거꼬리고사리, 가거애기닥나무 등 9종이다. 귀화식물은 11종이며 귀화율은 3.2%이다. Vascular plants of Island Gageo in Jellonamdo were investigated 10 times from August, 2005 to August, 2011. In the result of survey, the flora of this island consists of 341 taxa totally; 93 families, 246 genera, 289 species, 7 subspecies, 36 varieties and 9 forms. Yellow-fruit bearing plants of Neolitsea sericea which were found in this island are newly named as Neolitsea sericea (Bl.) Koidz. for. koreana M. Kim. There were 8 Korean endemic plants such as Hosta yingeri, Impatiens furcillata, Saussurea pseudo-gracilis, etc. Also 3 Korean endangered species which is designating by Ministry of Environment such as Osmanthus insularis and Cyrtosia septentrionalis and 9 rare and remarkable species such as Viburnum japonicum, Asplenium yoshinagae, Broussonetia kazinoki for. koreana, etc. were found in this island. Furthermore, 11 taxa of naturalized plants (3.2%) were also observed in this island.

Discovery of urinary metabolomic biomarkers for early detection of acute kidney injury

Won, A Jin,Kim, Siwon,Kim, Yoon Gyoon,Kim, Kyu-Bong,Choi, Wahn Soo,Kacew, Sam,Kim, Kyeong Seok,Jung, Jee H.,Lee, Byung Mu,Kim, Suhkmann,Kim, Hyung Sik The Royal Society of Chemistry 2016 Molecular bioSystems Vol.12 No.1

<P>The discovery of new biomarkers for early detection of drug-induced acute kidney injury (AKI) is clinically important. In this study, sensitive metabolomic biomarkers identified in the urine of rats were used to detect cisplatin-induced AKI. Cisplatin (10 mg kg(-1), i.p.) was administered to Sprague-Dawley rats, which were subsequently euthanized after 1, 3 or 5 days. In cisplatin-treated rats, mild histopathological alterations were noted at day 1, and these changes were severe at days 3 and 5. Blood urea nitrogen (BUN) and serum creatinine (SCr) levels were significantly increased at days 3 and 5. The levels of new urinary protein-based biomarkers, including kidney injury molecule-1 (KIM-1), glutathione S-transferase-alpha (GST-alpha), tissue inhibitor of metalloproteinase-1 (TIMP-1), vascular endothelial growth factor (VEGF), calbindin, clusterin, neutrophil, neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin, were significantly elevated at days 3 and 5. Among urinary metabolites, trigonelline and 3-indoxylsulfate (3-IS) levels were significantly decreased in urine collected from cisplatin-treated rats prior to histological kidney damage. However, carbon tetrachloride (CCl4), a hepatotoxicant, did not affect these urinary biomarkers. Trigonelline is closely associated with GSH depletion and results in insufficient antioxidant capacity against cisplatin-induced AKI. The predominant cisplatin-induced AKI marker appeared to be reduced in urinary 3-IS levels. Because 3-IS is predominantly excreted via active secretion in proximal tubules, a decrease is indicative of tubular damage. Further, urinary excretion of 3-IS levels was markedly reduced in patients with AKI compared to normal subjects. The area under the curve receiver operating characteristics (AUC-ROC) for 3-IS was higher than for SCr, BUN, lactate dehydrogenase (LDH), total protein, and glucose. Therefore, low urinary or high serum 3-IS levels may be more useful for early detection of AKI than conventional biomarkers.</P>

Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

Son, Ji Yeon,Kang, Yoon Jong,Kim, Kyeong Seok,Kim, Tae Hyung,Lim, Sung Kwang,Lim, Hyun Jung,Jeong, Tae Cheon,Choi, Dal Woong,Chung, Kyu Hyuck,Lee, Byung Mu,Kim, Hyung Sik Korean Society of ToxicologyKorea Environmental Mu 2014 Toxicological Research Vol.30 No.2

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.

Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

Ji Yeon Son,Yoon Jong Kang,Kyeong Seok Kim,Tae Hyung Kim,Sung Kwang Lim,Hyun Jung Lim,Tae Cheon Jeong,Dal Woong Choi,Kyu Hyuck Chung,Byung Mu Lee,Hyung Sik Kim 한국독성학회 2014 Toxicological Research Vol.30 No.2

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.

리더십 행동의 규정요인 및 유효성 검토 : An Expectancy Theory Approach

임무경,김석일,박일호 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.3

The purpose of this study was to examine the influence of the instrumentality perceptions (concerning the degree to which the leadership behavior is seen as leading to accomplish his own instructional objectives), extrinsic factors (characteristic of group, characteristics of followers, task uncertainty and favorableness for leader) and instrumentality perceptions (concerning the degree to which the leader is seen as leading to realize follower's objectives) on the leadership behavior (initiating structure and consideration), and the influence of the difference between two leadership measurements (leader's own and followers') on the effectiveness of sport clubs in community. The subjects were 54 leaders and 273 members of sport clubs in community. 1. The correlation between the instrumentality perceptions of Initiating structure and the actual leadership (initiating structure) were considerably high. 2. Significantly positive correlation between the instrumentality perceptions of leader by club members and the attitude toward the leadership of leader were found. 3. As to the effectiveness of clubs, coincidence clubs (leader's own evaluation and followers' on leadership) was higher than uncoincident clubs. These findings indicated that the leader's leadership behavior (initiating structure) could be predicated from the Expectancy Theory model and the difference between leader's own evaluation and that of club members' on leadership influenced on the effectiveness of sport clubs in community.

Original Article : Evaluation of Renal Toxicity by Combination Exposure to Melamine and Cyanuric Acid in Male Sprague-Dawley Rats

( Ji Yeon Son ),( Yoon Jong Kang ),( Kyeong Seok Kim ),( Tae Hyung Kim ),( Sung Kwang Lim ),( Hyun Jung Lim ),( Tae Cheon Jeong ),( Dal Woong Choi ),( Kyu Hyuck Chung ),( Byung Mu Lee ),( Hyung Sik Ki 영남대학교 약품개발연구소 2014 영남대학교 약품개발연구소 연구업적집 Vol.24 No.0

Melamine-induced nephrotoxicity is closely associated with crystal formation in the kidney caused by combined exposure to melamine (Mel) and cyanuric acid (CA). However, there are few dosage-finding studies for toxicological evaluation of chronic co-exposure to Mel and CA. The objective of this study was to investigate the possible mechanism by which a Mel and CA mixture lead to renal toxicity in rats. Mel and CA were co-administered to rats via oral gavage for 50 days. Nephrotoxicity was determined by measuring blood urea nitrogen (BUN) and serum creatinine (sCr) levels. Relative kidney weights were significantly increased in rats after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg) mixtures. BUN and sCr levels were significantly increased after Mel and CA co-exposure. Taken together, significant increase in KIM-1, NGAL, and calbindin levels were observed in the urine of rats exposed to Mel+CA (63/6.3 or 630/6.3 mg/kg) compared with the corresponding control group. Histological analysis revealed epithelial degeneration and necrotic cell death in the proximal tubules of the kidney after co-exposure to Mel+CA (63/6.3 or 630/6.3 mg/kg). Our data suggest that Mel-mediated renal toxicity may be influenced by CA concentrations in Mel-contaminated milk or foods.