• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.375-378
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• 2007

The selection of the support system is an important design parameter in design and construction of the tunnel using the new Australian tunnel method. It is a common practice to select the support based on the rock mass grade, in which the rock mass is classified into five rock groups. The method is applicable if the characteristics of the rock mass are uniform in the direction of tunnel excavation. However, such case is seldom encountered in practice and not applicable when the properties vary along the longitudinal direction. This study performs comprehensive three dimensional finite difference analyses to investigate the ground deformation pattern for cases in which the rock mass properties change in the direction of the tunnel axis. The numerically calculated displacements at the tunnel crown show that the displacement is highly dependent on the stiffness contrast of the rock masses. The results strongly indicate the need to select the support type $0.5\sim1.0D$ before the rock mass boundary. The paper proposes a new guideline for selecting the support type based the results of the analyses.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.476-479
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• 2007

The selection of the support system is an important design parameter in design and construction of the tunnel using the new Australian tunnel method. It is a common practice to select the support based on the rock mass grade, in which the rock mass is classified into five rock groups. The method is applicable if the characteristics of the rock mass are uniform in the vertical direction. However, such case is seldom encountered in practice and not applicable when the properties vary along the vertical direction. This study performs comprehensive three dimensional finite difference analyses to investigate the ground deformation pattern for cases in which the rock mass properties change in the vertical direction of the tunnel axis. The numerically calculated displacements at the tunnel crown show that the displacement is highly dependent on the stiffness contrast of the rock masses. The results strongly indicate the need to select the support type $0.5{\sim}1.0D$(vertical direction) on the rock mass boundary. The paper proposes a new guideline for selecting the support type based the results of the analyses.

• 상하수도학회지
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• 제20권4호
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• pp.509-518
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• 2006

Although final water of domestic water treatment plants almost contains highly corrosive characteristics, the countermeasures for eliminating internal corrosion of pipeline system have not been conducted yet by controlling water quality in plants. The technologies of internal corrosion control are to control water quality parameters(pH, Alkalinity, and Calcium Hardness etc.) and to use corrosion inhibitor. Under the conditions of domestic water treatment, first of all, the technologies of adjusting water quality parameters has to be considered. Otherwise, The technology of using corrosion inhibitor is favorably thought to be applied with the technology of adjusting water quality parameters in accordance with the result of availability for water treatment process. Since the technology of adjusting water quality parameter influences on other water treatment processes, the guideline of water quality management to be apt for water quality characteristic is required to be estabilished. While the selection of proper chemicals and technologies is dependent upon the raw water characteristics and water treatment process, typically, the technology of $Ca(OH)_2$ & $CO_2$ additions is considered more effective than other technologies in order to adjust pH and Alkalinity, increase $Ca^{2+}$ and form $CaCO_3$ film

• 상하수도학회지
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• 제27권6호
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• pp.723-730
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• 2013

Due to the event of hazardous chemical injection into a water storage tank in Hongseong, Chungcheongnam-do in 2012, the Korean Ministry of Environment has revised the enforcement rules of the Water Supply and Waterworks Installation Act to install surveillance equipments such as closed-circuit television(CCTV). However, the enforcement rules still do not provide concrete provision for installation of physical security equipments. Thus we studied vulnerability of small-scale water supplies in Korea and developed guidelines for the physical security system of the facilities. The guidelines include selection and recommendation of the physical security approaches and measures to detect, delay and response to the presence of an intruder in small-scale water supplies. The security features include protection utilities(e.g., fencing and fence topping), exterior intrusion detectors and alarms, locks and padlocks, surveillance utilities(e.g., CCTV), and others.

• 한국병원경영학회지
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• 제11권1호
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• pp.110-126
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• 2006

The purpose of the study is to find the factors influencing small or middle size clinics and hospitals CEOs' expectation level on the affiliation with the large size teaching hospitals. Data for analysis was collected to use self-administrative structured questionnaire on 164 CEOs of small or middle sized clinics and hospitals affiliated with large sized teaching hospital located in Kyung Ki Province. For the study, the researchers develop the constructs for questions on the expectation on the affiliation, the attitude such as confidence, knowledge on the affiliation, previous relationship of the affiliation, and selection guideline of the affiliation with exploratory factor analysis and reliability test. Through the confirmative factor analysis using AMOS 4, the researchers develop constructs based on exact relationship between constructs and questions. CEOs' expectation level on the affiliation is influenced on attitude or confidence, gender, types of clinics and hospitals, distance to the affiliated large hospital, types of recommender, and number of affiliated hospitals. Large sized hospitals that want to affiliation with other clinics and hospitals can promote the affiliation to consider these factors from the results.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.40-40
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• 2009

Construction firms have long sought success in the global construction market through diversifying revenue sources and project portfolios. The volume of international contracts has contributed to firms' sustained growth by mitigating the impact of the domestic market's cyclical nature. In spite of the importance of international construction, the uncertainty and dynamic changes surrounding global construction pose serious threats to global contactors. Over the last decade, the international construction industry has changed drastically in many ways, particularly including financial resource diversity, competition rules for the selection of contractors, and the terms of delivery systems requiring more competent total service providers. This paper investigates the important changes for global contractors through various documentation analysis as well as in-depth interviews with industry experts. This paper then analyzes the common strategies and lessons obtained from the cases of leading global contractors that have sustained their growth in the competitive global construction during the last decade. In addition, the authors further analyzed the comparisons between those firms and Korean contractors to discern any difference in sustaining their growth in the competitive market. It was found that those leading firms were quite proactive and responsive to changing markets by diversifying their market revenues to stabilize their revenue structure and enhancing their competency through a wide range of 'business convergence'. In addition, they significantly increased their upstream/downstream functional capabilities; hence becoming more competent service providers, able to grow in these rapidly changing market conditions. Finally, this paper benchmarks the critical strategies that support growth, which in turn can provide a strategic guideline for expansion into the global construction market.

• 한국항행학회논문지
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• 제15권5호
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• pp.735-741
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• 2011

본 논문에서는 고속 Binary CDMA 시스템에서 신호대잡음비의 추정 오차가 MMSE-DFE의 BER 성능에 미치는 영향을 분석하였다. MMSE 등화 알고리즘은 입력신호의 신호대잡음비 값이 필요하기 때문에, 프리엠블의 CAZAC 시퀀스로부터 신호대잡음비를 추정해야한다. 그러나 잡음과 ISI가 존재하는 환경에서는 정확한 신호대잡음비 추정이 불가능하므로 추정 오차가 발생하고, 이로 인해 등화기의 성능이 열화된다. 본 논문의 실험 결과는 MMSE-DFE 설계시에 SNR 추정 알고리즘의 선택 기준으로 활용될 수 있다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2016년도 춘계학술대회
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• pp.42-43
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• 2016

해양분야에 e-Navigation 전략이 도입되면서 안전한 항행 지원을 위해 기존의 제품을 재설계 하거나 새로운 제품 설계가 이루어지고 있다. 항행 지원에 소프트웨어시스템의 영향이 커지고 있기 때문에 안전하고 견고한 시스템의 설계는 매우 중요하며, 이를 위해 높은 품질의 확보가 필요하다. IMO에서는 이러한 제품 설계를 위해 적절한 품질을 보장하고 목적에 맞는 제품 설계에 대한 내용을 담고 있는 소프트웨어 품질 보증 및 인간 중심 설계 가이드라인을 공식 승인하였다. 가이드라인에서 품질 보증은 제품 품질, 데이터 품질, 사용상 품질을 만족할 것을 포함한다. 다양한 품질 속성을 만족하기 위해서는 품질 속성간의 우선순위화가 필요하다. 본 논문에서는 안전하고 견고한 소프트웨어 시스템을 위해 AHP기법을 이용하여 제품에 따른 품질 속성을 우선순위화 하고, 전 개발 단계에 걸쳐 품질 속성이 반영되고 평가 될 수 있도록 한다.

• 한국정보시스템학회지:정보시스템연구
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• 제16권2호
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• pp.1-33
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• 2007

Selecting and implementing competitive strategies based on e-business is extremely important since it determines if an enterprise can continue to grow or not. Accordingly, systematic and empirical study on the implementation of e-business based on competitive strategy is required, and in-depth studies considering various e-business development stages of enterprises are also needed. The purpose of this study is to present guideline for the staff in charge and managers of enterprises to achieve competitive advantage and to increase organizational performance in e-business environments. What we have found are as follows. (1) Factors greatly influencing on competitive strategy selection through e-business were environmental uncertainty, centralization, innovative culture, technological competence, and formalization. (2) Results of the relationship between competitive strategies and e-business performance showed that each strategy had different effects on financial performance, process performance, and customer performance. and (3) Data analysis between internal and external environmental factors and competitive strategy by each e-business development stage proved that the relationships between competitive strategy and e-business performance were different based on e-business development stage. Implications of the study and guidelines for the managers are provided in the paper.

• The Korean Journal of Pain
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• 제27권3호
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• pp.200-209
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• 2014

Background: Spinal opioid administration is an excellent option to separate the desirable analgesic effects of opioids from their expected dose-limiting side effects to improve postoperative analgesia. Therefore, physicians must better identify either specific opioids or adequate doses and routes of administration that result in a mainly spinal site of action rather than a cerebral analgesic one. Methods: The purpose of this topical review is to describe current available clinical evidence to determine what opioids reach high enough concentrations to produce spinally selective analgesia when given by epidural or intrathecal routes and also to make recommendations regarding their rational and safety use for the best management of postoperative pain. To this end, a search of Medline/Embase was conducted to identify all articles published up to December 2013 on this topic. Results: Recent advances in spinal opioid bioavailability, based on both animals and humans trials support the theory that spinal opioid bioavailability is inversely proportional to the drug lipid solubility, which is higher in hydrophilic opioids like morphine, diamorphine and hydromorphone than lipophilic ones like alfentanil, fentanyl and sufentanil. Conclusions: Results obtained from meta-analyses of RTCs is considered to be the 'highest' level and support their use. However, it's a fact that meta-analyses based on studies about treatment of postoperative pain should explore clinical surgery heterogeneity to improve patient's outcome. This observation forces physicians to use of a specific procedure surgical-based practical guideline. A vigilance protocol is also needed to achieve a good postoperative analgesia in terms of efficacy and security.