등방성 이종재료 내의 Ⅴ-노치 균열에 대한 응력강도계수 결정에 관한 연구

조상봉,정휘원,김진광 경남대학교 신소재연구소 1999 論文集 Vol.11 No.-

접합계면 V-노치 균열 문제는 고유치와 고유벡터 문제로 수식화할 수 있다. V-노치 균열첨단에서 응력특이성을 가지는 고유치가 존재한다. 상반일 등고선 적분법(RWCIM)은 고유치와 관련된 고유벡터의 계수를 구하는 한 가지의 방법이다. 상반일 등고선 적분법을 이용하여 접합계면 균열의 응력확대계수를 구하도록 시도하였다. 상반일 등고선 적분법으로 구한 응력확대계수와 경계요소법과 변위외삽법을 이용하여 구한 결과를 비교하였다. An inteiface 17-notched crack problem can be formulated as a eigenvalue problem. there are the eigenvalues which give stress singularities at the V-notched crack tip. The RWCIM is a method of calculating the eigenvector coefficients associated with eigenvalues. Obtaining the stress intensity factors for an interface crack in dissimilar materials was examined by the RWCIM. The results obtained for stress intensity factors using RWCIM were compared with those obtained by using the displacement extrapolation method and the BEM.

임상검체에서 분리된 Acinetobacter의 항균제 내성(1991-1997)

송호연,조성란,김휘준,고광균 대한화학요법학회 1998 대한화학요법학회지 Vol.16 No.2

목적 : 최근 원내감염의 중요 원인균으로 대두되고 있는 A. baumannii의 발생 양상 및 병동 별 항균제 내성의 변화 추이를 조사하여 치료시 적절한 항균제를 선택하는데 도움이 되는 자료를 제공하고자 하였다. 방법 : 1991년 1월부터 1997년 12월까지 7년간 한 대학병원의 입원환자로부터 분리 동정된 Acinetobacter의 균종별, 계절별, 임상검체별 분리양상을 조사하고 디스코 확산법에 의한 항균제 내성의 변화 추이 및 중환자실과 일반 병실에서의 항균제 내성 차이를 분석하였다. 결과 : 분리 동정된 Acinetobacter 4,128균주 중 91.5%가 A. baumannii로 연도에 따라 발생율이 증가하는 양상을 보였고 여름철이 호흡기계 검체로부터 가장 많이 분리되었다. A. baumannii로 imipenem과 ciprofloxacin을 제외한 대부분의 항균제에 높은 내성을 나타내었고 많은 항균제에서 내성율이 연도에 따라 점차 증가하였다. 3,777균주의 A. baumannii 중 45.2%가 중환자실 및 신생아실에서 분리되었는데 이는 중환자실 입원 환자수가 일반병동보다 훨씬 적은 것을 고려할 때 매우 높은 발병율임을 알 수 있었다. 또한 중환자실에서 분리된 균주의 다제내성율은 일반병동에서 분리된 균주보다 훨씬 높았다. 결론 : 중환자실에는 일반병동에 비해 다제내성율이 훨씬 높아 감염에 대한 저항력이 저하된 중증환자들의 생명을 끊임없이 위협하고 있는데 이런 다제내성균의 출현 및 원내감염을 줄이기 우한 중환자실만의 집중적인 대책이 수립되어야 할 것으로 사료된다. Background : Acinetobacter baumannii is recognized as an important causative agent of nosocomial infection. Therefore, it is important to understand the changing patterns of antimicrobial resistance to guide for antimicrobial therapy of infection by A. baumannii. So we compared the rate of miltidrug-resistance between ICU and general wards and we analyzed the trends of antimicrobial resistan changes during the past seven years. Methods : Acinetobacter isolated from 1991 to 1997 at a tertiary hospital were classified according to species, wards, seasons and clinical specimens. We tested the antimicrobial resistance by the standard disk diffusion method and compared the multidrug-resistant patterns of A. baumannii isolated from ICU with those from general wards. Results : Among the 4,128 Acinetobacter isolates, A. baymannii was the most common species(91.5%), followed by A. Iwoff??(8.5%), Acinetobacter species were isolated mainly from respiratory specimens during the summer. A. baumannii showed high resistance rates to most of antibiotics except imipenem and ciprofloxacin and resistance rates were increasing year after year. Forty-five percent of A. baumannii was isolated from ICU and neonate room, it showed higher multidrug-resistance rate than those generated from general wards. Conclusion : Multidrug-resistant. A. baumannii was predominant in ICU than general wards. It will contribute to increase of mortality due to nosocomial infection in severly ill patients. In order to reduce occuranc of multidrug-resistant isolates and noscomial infection in ICU, it is necessary to organize the intensive surveillance system in ICU.

자폐아동의 기본운동교육프로그램 참가가 지각운동능력발달에 미치는 영향

이창섭,이명휘,현광석,이창규,조병준 한국특수체육학회 2003 한국특수체육학회지 Vol.11 No.1

The purpose of this study was to examine how the program of basic movement can influence and change the capability of perceptive movement among the children with autism. Four subjects (age3-5) participated in the specially designed program, three times a week for four weeks. For the purpose of this study, Oseretsky's Motor Development Test and PMDT(perception-Movement development Diagnosis Test) were used. The results were as follows; First, the upper limb performance of the children with autism showed significant changes by the movement education program. Second, along with the development of upper limb performance, the motor development index of the children with autism showed significant changes. Third, the Oseretsky spectrum of movement, of the children with autism responded to the order of mono-movement capability, hand-movement and co-operative movement. Fourth, the movement education program was more effective for the children with autism than for the retarded children in view of motor development capability. Fifth, the movement education program was more effective for the child with autism of multi-movement characteristics.

Ab initio MO Study on N-Nitrosoazetidine-2-carboxylic Acid

Cho, Kwang-Hwi Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.1

Ab initio MO Study on N-Nitrosoazetidine-2-carboxylic Acid

Kwang-Hwi Cho* 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.1

Protein Structure Prediction Using the Hybrid Energy Function, Fragment Assembly and Double Optimization

Kwang-Hwi Cho,Julian Lee,Taek-Kyun Kim 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.1

We perform protein structure prediction by combining a hybrid energy function, fragment assembly, and double optimization. In the hybrid energy function, all the backbone atoms are described explicitly, but the side-chain is modeled as a few interaction centers in order to reduce computational costs. We reduce the search space by using a fragment assembly method, where the local structure of the backbone is obtained from a structural database using similarity of sequence features, and only the global tertiary packing of fragments is determined by minimizing the energy. The structure with the minimum energy is obtained using double optimization, where a combination of backbone fragments with minimum energy is obtained using the conformational space annealing (CSA) method, and the optimal side-chains for a given backbone structure are obtained using simulated annealing. We show the feasibility of our method by performing test predictions on two proteins, 1bdd and 1e0l, that belong to distinct structural classes. We perform protein structure prediction by combining a hybrid energy function, fragment assembly, and double optimization. In the hybrid energy function, all the backbone atoms are described explicitly, but the side-chain is modeled as a few interaction centers in order to reduce computational costs. We reduce the search space by using a fragment assembly method, where the local structure of the backbone is obtained from a structural database using similarity of sequence features, and only the global tertiary packing of fragments is determined by minimizing the energy. The structure with the minimum energy is obtained using double optimization, where a combination of backbone fragments with minimum energy is obtained using the conformational space annealing (CSA) method, and the optimal side-chains for a given backbone structure are obtained using simulated annealing. We show the feasibility of our method by performing test predictions on two proteins, 1bdd and 1e0l, that belong to distinct structural classes.

Tautomerism of Cytosine on Silver, Gold, and Copper: Raman Spectroscopy and Density Functional Theory Calculation Study

Cho, Kwang-Hwi,Joo, Sang-Woo Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.1

Tautomerism of pyrimidine base cytosine has been comparatively examined on nanoparticle and roughened plate surfaces of silver, gold, and copper by surface-enhanced Raman scattering (SERS). The SERS spectrum was found to be different depending on the metals and their substrate conditions suggesting the dissimilar population of various tautomers of cytosine on the surfaces. The ab initio calculations were performed at the levels of B3LYP, HF, and MP2 levels of theory with the LanL2DZ basis set to estimate the energetic stability of the tautomers with the metal complexes as well as the gas phase state. The amino group and N3-coordinated tautomer was predicted to be more favorable for bonding to Au, whereas the hydroxyl and N1-coordinated zwitter ionic form is most stable with Ag and Cu as a bidentate form from the DFT calculation. The binding energy with the Ag atom is calculated to be smaller than those with the Au and Cu atoms in line with the temperature-dependent SERS spectra of cytosine.

Rezen(감로수)을 활용한 절식프로그램이 프리다이버의 피로도 개선에 미치는 영향

조휘성(Hwi Sung Cho),양진광(Jin Kwang Yang),신승우(Seung Uoo Shin),김동환(Dong Hwan Kim),신현택(Hyun Taeg Shin),조재흥(Jae Heung Cho),김태오(Tae Oh Kim),서연호(Yeon Ho Seo),정원석(Won Seok Chung) 대한스포츠한의학회 2022 대한스포츠한의학회지 Vol.22 No.1

Objectives We conducted a survey to investigate the fasting program using Rezen is effective for freediving. Methods A survey was conducted before and after the freediving fasting program for 15 participants. Participants were athletes who participated in a freediving competition held in Cebu Mactan, Philippines. A structured questionnaire of freediving fasting program was distributed to responders and all data were statistically analyzed. Results All respondents were freediving intermediate or higher, and 9 out of 15 were instructors. There was no significant difference in the results of the subjective symptom questionnaire to check the side effects of the fasting program. As a result of revised Chalder’s fatigue scale, there was a significant improvement in 6 items of alertness, motivation, energy, muscle strength, physical strength, and concentration among 11 items, and the total score was improved from 24.60±4.42 to 18.87±5.17, which was significantly improved by 5.73±5.34 points. As a result of the taste evaluation of Rezen, 6 people responded ‘Excellent’, 4 people responded ‘good’, 3 people responded ‘average’, and 2 people responded ‘Below average’. When asked whether the fasting program was helpful to freediving, 1 people responded ‘Extremely helpful’, 7 people responded ‘Very helpful’, 4 people responded ‘Somewhat helpful’, 1 people responded ‘Not so helpful’, and 1 people responded ‘Not at all’. Conclusions The possibility that the fasting program using Rezen could be effective for freediving by improving fatigue was confirmed, and the potential of Rezen as a sports drink was improved.

Hepatitis B Surface Antigen Quantification across Different Phases of Chronic Hepatitis B Virus Infection Using an Immunoradiometric Assay

( Kwang Hyun Chung ),( Won Kim ),( Byeong Gwan Kim ),( Ho Young Lee ),( Eunhyo Jin ),( Yuri Cho ),( Ji Yeon Seo ),( Hwi Young Kim ),( Yong Jin Jung ),( Ji Won Kim ),( Ji Bong Jeong ),( Kook Lae Lee ) 대한소화기학회 2015 Gut and Liver Vol.9 No.5

Background/Aims: Quantification of hepatitis B surface antigen (HBsAg) is an emerging serologic test and may be useful for identifying treatment strategies for chronic hepatitis B (CHB). This study aimed to evaluate HBsAg titers during the natural course of CHB and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different CHB phases measured using an immunoradiometric assay (IRMA). Methods: CHB phases were defined on the basis of HBV DNA concentrations, the presence of hepatitis B e antigen/antibody (HBeAg/Ab) and serum alanine aminotransferase levels. Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were compared using 627 serum samples. Results: Mean HBsAg titers were significantly higher in the immunotolerant (IT) phase and immunoreactive (IR) HBeAg-positive phase than in the low-replicative (LR) and HBeAg-negative CHB (ENH) states. The correlation between HBsAg titers and HBV DNA concentrations was modest in the IT (n=36, r=0.804, p<0.001) and IR (n=48, r=0.773, p<0.001) phases, and it was poor in the LR state (n=116, r=0.289, p=0.002); however, no significant correlation was observed in the ENH state (n=67, r=0.146, p=0.237) or in the oral nucleos(t)ide analogue-treated group (n=267). Conclusions: HBsAg quantification using IRMA might be useful for discriminating different CHB phases and different stages of chronic liver disease. (Gut Liver 2015;9:657-664)

사회적기업가의 포용적 리더십이 조직몰입에 미치는 영향

조영복(Cho, Young-Bohk),이나영(Lee, Na-Young),박광휘(Park, Kwang-Hwi) 사회적기업연구원 2018 사회적기업연구 Vol.10 No.2