Evaluation of Hot Deformation and Dynamic Recrystallization Behaviors of Advanced Reduced-Activated Alloy (ARAA)

Sang‑Wook Kim,Hyeon‑Woo Son,Taek‑Kyun Jung,Young‑Bum Chun,Yi‑Hyun Park,Ji‑Woon Lee,Soong‑Keun Hyun 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The hot deformation behavior of advanced reduced-activation alloy (ARAA) was investigated using hot torsion tests. Thefl ow stress decreased as deformation temperature increased and as strain rate decreased. The fl ow behavior demonstratedthe typical dynamic recrystallization (DRX). Based on the constitutive analysis of peak stress, the activation energy for hotdeformation was found to be 330.3 kJ mol −1 . Peak stress was analyzed as a function of the Zener–Hollomon parameter, andcalculated and experimental values were in good agreement. A DRX kinetic model for ARAA was derived with deformationconditions based on the Avrami-type model. It was confi rmed that the volume fraction of dynamically recrystallized grainsincreased as deformation temperature increased and as strain rate decreased. The necklace structure and grain boundarybulging were observed in the deformed microstructure of ARAA. The suggested DRX mechanism for ARAA during hotworking is discontinuous DRX.

생활체육참가정도와 Wellness지수, 생활만족의 관계

김상국(Kim Sang-Kook),이광욱(Lee Kwang-Wook) 한국체육과학회 2005 한국체육과학회지 Vol.14 No.2

The purpose of this study was to examine the relationships among leisure sports participation, wellness inventory and life satisfaction, The subjects were 645 adults(male=348; female=297) aged more than 20 years who participated in community-based leisure sports programs of the fitness clubs in Seoul and Incheon City, Korea, The degree of leisure sports participation; items on the Wellness scale developed and used by Kim Sang-kuk based on Wellness: Concepts and Application developed by Anspaugh et al.(l994); and the Korean version of the Satisfaction with Life scale(SWLS) developed by Diener, Emons, Larsen & Griffin(1985) translated and used by Lee Jong-kil(1992). The validity of the questionnaire was verified through specialists' meeting, the pilot test, and exploratory and confirmatory factor analysis. The reliability of the questionnaire was found to be Cronbach' s α=.66~.83. The methods of statistics used to analyze the collected data were correlation analysis and multiple regression using SPSS WIN 11.5. As a result, the following findings were obtained: First, it was found that the degree of leisure sports participation had an effect on the wellness inventory. That is, participants who participated in the leisure sports program longer, more frequently, and more actively had the higher level of recognition on the wellness inventory than any other group. Second, it was found that the degree of leisure sports participation had an effect on the life satisfaction. That is, participants who participated in the leisure sports program longer, more frequently, and more actively the higher level of recognition on the life satisfaction than any other group. Third, it was found that the wellness inventory had an effect on the life satisfaction. That is, the participants who were highly conscious of physical, social, mental health domains as subfactors of the wellness inventory had the higher level of life satisfaction.

해외사례 벤치마킹에 기반한 국내 CM 대가체계 개선 시사점 도출

김상범,이정대,김재욱,Kim, Sang-Bum,Lee, Jeong-Dae,Kim, Jae-Wook 한국건설관리학회 2008 건설관리 : 한국건설관리학회 학회지 Vol.9 No.1

국내 CM은 2001년 건설산업기본법에 의해 개념과 범위가 정의된 후 지속적인 성장을 계속해 오고 있다. 하지만, 이러한 CM 제도에 기반한 성장에도 불구하고 국내에서의 CM 적용성과는 기대치에 비해 상대적으로 낮은 것으로 나타났다. 그 주요원인의 하나로 국내 CM제도가 책임감리에 비하여 업무범위가 넓지만, 대가기준은 책임감리에 비해 낮기 때문인 것으로 분석되었다. 따라서, 국내 CM 대가체계의 합리적인 기준을 정립하는 것이 시급할 것으로 판단된다. 본 연구에서는 CM 대가체계의 합리적인 기준을 마련하기 위하여 CMAA, ASCE, DOE, DOL 등의 다양한 해외사례 벤치마킹 연구를 통하여 국내 CM 대가체계를 비교하여 대가 상승요인을 추정하고 대가산정 개선방향을 제시하였다. 분석결과 대가수준은 해외에 비하여 현저하게 낮은 수준인 것으로 판단되었으며, 업무범위는 해외와 비교하여 그 폭이 좁으며 획일적인 구조를 가진 것으로 분석되었다. 따라서, 본 연구에서는 글로벌스탠다드에 따르는 국내 CM 대가체계를 개선하기 위하여 실비정액보수가산(Cost Plus Fixed Fee) 방식을 제시하고, 입 낙찰 전반에 걸친 CM 대가체계에 대한 기준(Framework)을 제시하였다. The Korean Construction Industry significantly contributed to the Korean economic development not only by preparing the domestic infrastructure but also by successfully conducting various international projects. However, major incidents such as the collapse of Sung-Su Bridge and Sam-Pung Department Store along with stagnation of Korean Economy have raised questions about underlying systematic problems of the Korean Construction Industry. As a solution to resurrect the Korean Construction Industry, the Construction Management (CM) system introduced in late 1990's and increasingly utilized as an innovative delivery system. Despite of the fast growth of CM, the performance of CM has not been up to the hype and low CM fee has been identified as one of the main reasons of unsatisfactory CM performance. Therefore, this research attempted to propose ways of improving 'CM Fee Guidelines' published by Korean Ministry of Construction and Transportation by conducting a benchmarking study on Global Standards of estimating CM Fee. International organizations benchmarked in this research include CMAA, ASCE, DOL, DOE, etc. Various investigation and analysis revealed that Korean 'CM Fee Guidelines' need to significantly modified comparing to Global Standards. This research also tried to prepare recommendations to improve the CM deliver system focusing on the 'Method of CM Fee Estimation' and Selection of a CM firm as an owner's agent.

Interactions between Chicken Salt-soluble Meat Proteins and Makgeolli Lees Fiber in Heat-induced Gels

Yun Sang Choi,Kwoan Sik Park,Hack Youn Kim,Hyun Wook Kim,Dong Heon Song,Hai Jung Chung,Ju Woon Lee,Cheon Jei Kim 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.6

The technological effects of Makgeolli lees fiber (0, 0.5, 1.0, 2.0, and 4.0%) on chicken salt-soluble breast meat proteins in a model system on proximate composition, physicochemical properties, and textural properties were investigated. Makgeolli lees fiber was obtained from Makgeolli brew processing, and the by-products showed good dietary fiber. The moisture and ash contents, water holding capacity, redness, yellowness, hardness, and apparent viscosity of chicken salt-soluble meat protein heat-induced gel systems with Makgeolli lees fiber were all higher than the control without Makgeolli lees fiber. However, protein solubility and electrophoretic patterns did not differ among the control and treatments with Makgeolli lees fiber samples. The chicken salt-soluble protein heat-induced gel systems incorporating Makgeolli lees fiber had improved water holding capacity, textural properties, and viscosity due to Makgeolli lees fiber addition. These results suggest that the addition of 4.0% Makgeolli lees fiber to gel is helpful to improve the physical properties of heat-induced gels.

Interactions between Chicken Salt-soluble Meat Proteins and Makgeolli Lees Fiber in Heat-induced Gels

Choi, Yun-Sang,Park, Kwoan-Sik,Kim, Hack-Youn,Kim, Hyun-Wook,Song, Dong-Heon,Chung, Hai-Jung,Lee, Ju-Woon,Kim, Cheon-Jei Korean Society for Food Science of Animal Resource 2011 한국축산식품학회지 Vol.31 No.6

The technological effects of Makgeolli lees fiber (0, 0.5, 1.0, 2.0, and 4.0%) on chicken salt-soluble breast meat proteins in a model system on proximate composition, physicochemical properties, and textural properties were investigated. Makgeolli lees fiber was obtained from Makgeolli brew processing, and the by-products showed good dietary fiber. The moisture and ash contents, water holding capacity, redness, yellowness, hardness, and apparent viscosity of chicken salt-soluble meat protein heat-induced gel systems with Makgeolli lees fiber were all higher than the control without Makgeolli lees fiber. However, protein solubility and electrophoretic patterns did not differ among the control and treatments with Makgeolli lees fiber samples. The chicken salt-soluble protein heat-induced gel systems incorporating Makgeolli lees fiber had improved water holding capacity, textural properties, and viscosity due to Makgeolli lees fiber addition. These results suggest that the addition of 4.0% Makgeolli lees fiber to gel is helpful to improve the physical properties of heat-induced gels.

Optimal Design of the Reflector Antenna to Improve Performance of C-Band Quad-Pol ScanSAR Systems

Sang-Burm Ryu,Hyeon-Cheol Lee,Sang-Gyu Lee,Jung-Hwan Lim,Jae Wook Lee,Taek-Kyung Lee 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.2

Color stable white phosphorescent organic light emitting diodes with red emissive electron transport layer

Wook Kim, Jin,Yoo, Seung Il,Sung Kang, Jin,Eun Lee, Song,Kwan Kim, Young,Hwa Yu, Hyeong,Turak, Ayse,Young Kim, Woo American Institute of Physics 2015 JOURNAL OF APPLIED PHYSICS - Vol.117 No.24

BI-17 EARLY COGNITIVE FUNCTION TESTS PREDICT EARLY PROGRESSION IN NEWLY-DIAGNOSED GLIOBLASTOMA

Lee, Soon-Tae,Lee, Kyung-Min,Kim, Jin Wook,Park, Min-Jung,Lim, Jung-Ah,Choi, Seung-Hong,Kim, Tae Min,Lee, Se Hoon,Park, Sung-Hye,Kim, Il-Han,Park, Chul-Kee Oxford University Press 2014 Neuro-oncology Vol.16 No.suppl5

<P>BACKGROUND: Cognitive dysfunction is a characteristic of tumor infiltration and a major morbidity causing functional deterioration in glioblastoma patients. Here we investigated whether pre-operative cognitive function tests can predict early prognosis in glioblastoma. METHODS: Consecutive patients who underwent glioma surgery were evaluated with pre-operative cognitive function tests, including Mini-Mental State Examination, Geriatric Depression Scale, Digit Span Tests (forward and backward), Controlled Oral Ward Association Test, Trail-Making Tests (TMT, type a, b, and c), and Stroop Tests. Pathologically-confirmed glioblastoma were treated with the standard protocol using radiation and temozolomide, and the 6-month progression-free survivals (PFS-6) were analyzed. RESULTS: Among 126 patients who underwent glioma surgery, 55 patients were diagnosed as glioblastoma, and 50 patients were finally eligible for the PFS-6 analysis. Thirty four patients (68%) achieved PFS-6. In the comparison of those without progression (PFS-6) with those with progression (No-PFS-6), there was no difference in the patients' demographics, tumor locations, tumor sizes, performance scores, initial symptoms, and genetic characteristics of tumors. The PFS-6 patients had higher rates of gross total resection, more use of concomitant chemo-radiation, and longer years of total education, than the no-PFS-6 patients. In the cognitive function tests, the PFS-6 patients had better performance in TMT-a, and TMT-b. Other cognitive function tests were not associated with PFS-6. In multivariate logistic regression, TMT-b was the only independent predictor for PFS-6, while age (<50), total education year (>12 yr), gross total resection, concomitant chemo-radiation, and TMT-a were not. Patients with good performance in TMT-b not only showed better early prognosis in the Kaplan-Meier survival analysis, but also had better recursive partitioning analysis classes. CONCLUSION: Our results indicate that the early cognitive function test before surgery can predict the early prognosis in glioblastoma. Poor executive function and slow psychomotor speed as detected in TMT suggest early progression of the tumor.</P>

A Ku-Band Low-Loss Traveling-Wave Power Divider using a Hollow Substrate Integrated Waveguide and Its Microstrip Transition

Sung-June Hong,Min-Pyo Lee,Seil Kim,Jun-Su Lim,Dong-Wook Kim 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.2

In this paper, we present a Ku-band low-loss traveling-wave power divider that uses a hollow substrate integrated waveguide (HSIW). For easy connection with microstrip-based devices and circuits, a low-loss transition between the microstrip line and the HSIW structure was implemented using C-cut via holes at the discontinuity interface, which reduces radiation and leakage effects and improves mismatch performance. To validate the performance of the transition, a back-to-back microstrip-to-HSIW transition was designed, fabricated, and measured from 12.5 GHz to 15.5 GHz. The measured results showed a return loss of 18 dB or more and an insertion loss of 0.5 ± 0.07 dB. An HSIW-based, low-loss 1:3 traveling-wave power divider was fabricated and measured from 13.5 GHz to 14.5 GHz. The power divider showed a return loss of at least 21 dB, an insertion loss of 0.57 ± 0.03 dB, and a power combining efficiency of 87.1%–88.3%.

Risk Factors and Clinical Outcomes Associated with Cytomegalovirus Colitis in Patients with Acute Severe Ulcerative Colitis :

Lee, Ho-Su,Park, Sang Hyoung,Kim, Sung-Han,Kim, Jihun,Choi, Jene,Lee, Hyo Jeong,Kim, Wan Soo,Lee, Jeong-Mi,Kwak, Min Seob,Hwang, Sung Wook,Yang, Dong-Hoon,Kim, Kyung-Jo,Ye, Byong Duk,Byeon, Jeong-Sik Oxford University Press 2016 Inflammatory bowel diseases Vol.22 No.4

<P>Background: Cytomegalovirus (CMV) colitis can contribute to an unfavorable outcome of acute severe ulcerative colitis (ASUC). The purpose of this study was to evaluate the clinical outcomes of ASUC according to the CMV status and identify risk factors for CMV colitis in patients with ASUC. Methods: We retrospectively analyzed patients with ASUC from 2011 to 2014 according to the criteria of Truelove and Witts. CMV colitis was diagnosed by histopathological and/or immunohistochemical analysis of tissue samples. The risk factors for CMV colitis were investigated and clinical outcomes were assessed using the rate of rescue therapy and colectomy. Results: Of 149 patients with ASUC, 50 (33.6%) were diagnosed with CMV colitis. During admission, 16 of 149 patients (10.7%) underwent colectomy: 7 of 50 (14.0%) in the ASUC-CMV group versus 9 of 99 (9.1%) in the ASUC-only group (P = 0.364). The need for rescue therapy was 2.28-fold higher in the ASUC-CMV group than in the ASUC-only group in multivariate analysis (95% confidence interval, 1.10-4.72). Multivariate analysis also revealed that recent use of high-dose steroids (odds ratio, 3.30; 95% confidence interval, 1.33-8.19) and a higher Mayo score (odds ratio, 1.58; 95% confidence interval, 1.05-2.38) were risk factors for CMV colitis. Conclusions: CMV colitis often occurs in ASUC, particularly in patients who have recently been treated with high-dose steroids and have a higher Mayo score on admission. Patients with ASUC and CMV colitis seem to have a poorer prognosis, as indicated by the greater need for rescue therapy.</P>