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.

Detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus using duplex real-time PCR assay with melting curve analysis on fresh lettuce

Lee, Na-Ri,Kwon, Kyung-Yoon,Choi, Sung-Wook,Koo, Min-Seon,Chun, Hyang-Sook The Korean Society of Food Hygiene and Safety 2011 한국식품위생안전성학회지 Vol.26 No.2

In this study, two duplex real-time PCR approach with melting curve analysis is presented for the detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus, which are important food-borne bacterial pathogens usually present in fresh and/or minimally processed vegetables. Reaction conditions were adjusted for the simultaneous amplification and detection of specific fragments in the ${\beta}$-glucuronidase (uidA, E. coli), thermonuclease (nuc, S. aureus), hemolycin (hly, L. monocytogenes) and tetrathionate reductase (ttr, Salmonella spp.) genes. Melting curve analysis using a SYBR Green I real-time PCR approach showed characteristic $T_m$ values demonstrating the specific and efficient amplification of the four pathogens; $80.6{\pm}0.9^{\circ}C$, $86.9{\pm}0.5^{\circ}C$, $80.4{\pm}0.6^{\circ}C$ and $88.1{\pm}0.11^{\circ}C$ for S. aureus, E. coli O157:H7, L. monocytogenes and Salmonella spp., respectively. For all the pathogens, the two duplex, real-time PCR was equally sensitive to uniplex real-time PCR, using same amounts of purified DNA, and allowed detection of 10 genome equivalents. When our established duplex real-time PCR assay was applied to artificially inoculated fresh lettuce, the detection limit was $10^3$ CFU/g for each of these pathogens without enrichment. The results from this study showed that the developed duplex real-time PCR with melting curve analysis is promising as a rapid and cost-effective test method for improving food safety. 본 연구에서는 신선편의 채소와 과일에서 주로 검출되는 대장균(E. coli Ol577:H7), 리스테리아(L. monocytogenes), 살모넬라(Salmonella, spp.), 형색포도상구균(S. aureus)을 검출하고 동정할 수 있는 real time PCR 방법을 melting curve 분석을 활용하여 single tube 반응으로 두 종의 식중독균을 동시 검출하는 방법을 개발하고자 하였다. 대장균의 ${\beta}$-glucuronidase (uidA), 황색포도상구균의 thermonuclease (nuc), 리스테리아의 hemolycin (hly), 살모넬라의 tetrahionate reductase (ttr) 를 특이적으로 검출할 수 있는 4종의 프라이머 세트에 대한 real-time PCR의 melting curve 분석을 통하여 황색포도상구균과 대장균 동시분석 시 $T_m$ 값이 $80.6{\pm}0.9^{\circ}C$와 $86.9{\pm}0.5^{\circ}C$, 리스테리아와 살모넬라 동시분석 시 Tm 값이 $80.4{\pm}0.6^{\circ}C$와 $88.1{\pm}0.11^{\circ}C$로 확인하였고, 그 결과 정제되어진 각 식중독균의 genomic DNA를 주형으로 한 duplex real-time PCR 방법이 uniplex real-time PCR 방법과 마찬가지로 10 genome equivalents 까지 검출할 수 있는 민감도를 나타내었다. 또한, 양배추에 네 종의 식중독균을 접종하고, 증균배양 없이 DNA를 추출하여 duplex real-time PCR 을 수행한 결과 모든 식종목균에서 $10^3$ CFU/g의 검출 한계를 나타내었다. 결과적으로 개발된 melting curve 분석을 이용한 duplex real-time PCR 방법은 식품안전 증진을 위한 시간, 노동력, 비용 절감에 있어서 유효한 방법이 될 것으로 판단된다.

Long-term Follow up of<i>Helicobacter pylori</i>IgG Serology After Eradication and Reinfection Rate of<i>H. pylori</i>in South Korea

Lee, Jung Hoon,Kim, Nayoung,Chung, Jae Il,Kang, Kyung Phil,Lee, Sang Hyup,Park, Young Soo,Hwang, Jin-Hyeok,Kim, Jin-Wook,Jeong, Sook-Hyang,Lee, Dong Ho,Jung, Hyun Chae,Song, In Sung Wiley (Blackwell Publishing) 2008 HELICOBACTER -CAMBRIDGE USA- Vol.13 No.4

<P>BACKGROUND: Serology is widely used for epidemiologic research of Helicobacter pylori. However, there is limited information on the long-term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long-term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea. METHODS: Among 247 patients, who were enrolled during 2003-07, 185 patients with invasive H. pylori test positive received proton pump inhibitor-based triple therapy, and follow-up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication. RESULTS: The initial H. pylori IgG optical density (OD(450 nm)), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests. CONCLUSION: The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori, in Korea, was found to be very low, 2.94% per year.</P>

A Bluetooth Scatternet Reformation Algorithm

Lee Han-Wook,Kauh Sang-Ken The Korea Institute of Information and Commucation 2006 Journal of communications and networks Vol.8 No.1

Bluetooth is reputed as a wireless networking technology supplying ad-hoc networks between digital devices. In particular, Bluetooth scatternet is an essential part of dynamic ad-hoc networks. Yet, there have not been sufficient researches performed on scatternet environment. This paper proposes a scatternet reformation algorithm for ad-hoc networks for instances where some nodes enter or leave the scatternet. The proposed algorithm is a general algorithm that can be applied to many types of Bluetooth scatternet regardless of the topology. The proposed algorithm is made for two reformation cases, i.e., nodes leaving and nodes entering. For the reformation when nodes leave a scatternet, the recovery node vector (RNV) algorithm is proposed. It has short reformation setup delay because the process involves a single page process (not including inquiry process). For the reformation when nodes enter a scatternet, the entry node algorithm is proposed. This is a simple and easily implementable algorithm. In this paper, real hardware experiments are carried out to evaluate the algorithm's performance where the reformation setup delay, the reformation setup probability and the data transfer rate are measured. The proposed algorithm has shown improvement in the reformation setup delay and probability.

Quasieigenstate evolution in open chaotic billiards

Lee, Sang-Bum,Yang, Juhee,Moon, Songky,Lee, Soo-Young,Shim, Jeong-Bo,Kim, Sang Wook,Lee, Jai-Hyung,An, Kyungwon American Physical Society 2009 Physical review. A. Atomic, molecular, and optical Vol.80 No.1

The Urate-lowering Efficacy and Safety of Febuxostat in Korean Patients with Gout

( Sung Hwan Park ),( Yeong Wook Song ),( Won Park ),( Eun Mi Koh ),( Bin Yoo ),( Soo Kon Lee ),( Dae Hyun Yoo ),( Yun Jong Lee ),( Hyun Ah Kim ),( Hyo Jin Choi ),( Ho Youn Kim ),( Hyong Gi Jung ) 대한류마티스학회 2013 대한류마티스학회지 Vol.20 No.4

Objective. To compare the urate-lowering efficacy and the safety of febuxostat, allopurinol and placebo in Korean patients with gout for 4 weeks. Methods. Subjects (n=182) with gout were randomized to febuxostat (40, 80, 120 mg), allopurinol 300 mg, or placebo group. The primary end point was the proportion of subjects whose serum urate concentration fell to less than 6.0 mg/dL after the 4-week treatment. Results. The primary end point was reached at 25.7%, 80.0% and 83.3% of patients receiving 40, 80 and 120 mg of febuxostat, respectively, 58.3% of those receiving 300 mg of allopurinol and none of the placebo (p<0.001: each febuxostat dose or allopurinol group versus placebo group, p=0.0484 and p=0.0196: febuxostat 80 and 120 mg compared with allopurinol, respectively). The number and proportion of subjects who developed adverse events (AEs) were 13 subjects (37%), 14 (39%) and 18 (50%) in the febuxostat of 40, 80 and 120 mg group, respectively, 21 (57%) in the allopurinol 300 mg group and 17 (46%) in the placebo group. No statistically significant differences in the incidence rates of adverse events were observed between the groups. There was no significant difference in gout flare-up incidence. Conclusion. Febuxostat, 80 mg or 120 mg, was more effective than allopurinol (300 mg) or placebo, when lowering the serum urate. The safety of febuxostat and allopurinol was comparable.