• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.485-490
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• 2003

최근 대내외적인 건설환경의 급격한 변화와 건설공사의 대형화${\cdot}$복잡화 추세는 내외부적으로 많은 리스크 요인을 증대시키고 있기 때문에, 이에 대한 합리적이고 효율적인 관리방안의 중요성이 크게 대두되고 있다. 본 연구에서는 이러한 리스크 관리방안의 하나로서, 사업추진과정에서의 공사비 증액이 매우 제한되어 있어 입찰단계에서 견적금액의 불확실성 요소(예비비)를 고려해야만 하는 턴키공사 등 대형 건설공사를 대상으로, 이에 내재된 리스크요인의 정량화를 통해 합리적이고 적절한 예비비를 산정할 수 있는 모델을 제시하고자 한다. 예비비 산정모델의 개발을 위하여 실제 수행된 프로젝트를 선정하여 각 공사의 예비비 집행현황, 공사비 현황 등의 자료를 토대로 공사비에 영향을 미치는 인자를 도출하였으며, 몬테칼로 시뮬레이션(Monte Carlo Simulation)과 영향도(Influence Diagram), 의사결정 수형도(Decision Tree)를 혼합한 CRM(Cost Risk Model)을 적용하여 이러한 리스크 인자의 영향을 구조화하였다. 또한 구축된 모델을 기 완료된 대형공사에 적용하여 그 타당성을 검증하고자 하였다.

• 한국건설관리학회논문집
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• 제7권2호
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• pp.109-117
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• 2006

건설산업의 경쟁은 신규 건설시장 축소, 최저가 입찰제도, 주 5일근무제도, 후분양제도의 도입 등에 따라 더욱 심화되고 있다. 이러한 건설환경의 급격한 변화는 산업의 주축을 이루고 있는 건설사들로 하여금 변화에 적응하고 더 나아가 새로운 환경을 선도하기 위한 다각적인 노력을 요구하고 있다. 그러나 건설공사는 공기지연을 유발하는 수많은 불확실성이 존재하고 있으며 이러한 불확실성에 대한 인식과 그에 따른 체계적인 전략수립과 관리가 부진한 경우 건설공사의 공기경쟁력을 확보하는 것은 매우 어렵다. 이에 본 연구는 적정 공사기간의 확보, 공기단축의 필요성, 기존의 공정전략 수립에 대한 연구가 부족함을 인식하고 건설사의 전반적인 전략 수립이 아닌 공기경쟁력 확보 측면에서 연구의 범위를 한정하였다. 본 연구는 건설산업의 대내외적 환경 분석과 SWOT 분석을 통하여 공기경쟁력 확보를 위한 전략을 수립하고 이를 이행하기 위한 선결과제를 도출하는 것을 목적으로 한다.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.119-127
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• 2005

최근의 건설시장 축소와 주 5일 근무제도, 공기단축형 입찰제도의 도입, 후분양제도의 도입 등의 제도적 변화에 따라 건설 수주 경쟁은 더욱 치열해지고 있다. 그러나 건설공사는 공기지 연을 유발하는 수많은 공정리스크가 존재하고 있으며 이러한 공정리스크에 대한 인식과 그에 따른 체계적인 관리가 부진한 경우 건설공사의 경쟁력을 확보하는 데 여러 어려움이 존재한다. 이러한 문제점을 해결하기 위한 기존 연구는 공정리스크의 분류, 공정 리스크의 관리, 리스크 관리를 위한 시스템 개발에 치중하였다. 이에 본 연구는 전체 공정에 영향력이 크며, 위험발생 확률이 높은 철근콘크리트공사를 대상공종으로 선정하고 기존연구를 바탕으로 수차례의 전문가 면담과 난상토론을 실시하여 현실적인 리스크 요인과 관리방안을 제시하였다.

• Safety and Health at Work
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• 제3권2호
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• pp.140-145
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• 2012

Objectives: To understand the personal experiences of mine workers that have experienced job relocation due to silicosis at the Andina Division of Corporaci$\acute{o}$n Nacional del Cobre (CODELCO), Chile. The purpose of the study was to provide useful information for the development of new local, business and public policies for the care of workers with silicosis. Methods: A qualitative study based on a practical case study of 5 workers. The information was collected by means of structured individual interviews. The method of analysis was phenomenology. Results: The corporal axis was the most commented upon. It included awareness of the illness, body pains, fatigue, and antagonistic mood disorders (sadness, or the difficulty in finding meaning in life). As far as personal relationships, there was evidence of strong relationships with family, coworkers and friends, as well as extended family. Over all, the experience of relocation was positive with periods of impatience and uncertainty. The job reassignment provided a new and pleasant context for the relocated workers and in the process improved their perception of their quality of life. Conclusions: A multidisciplinary team should attend mine workers relocated because of silicosis by addressing the mental and physical aspects of their disease, along with the integral participation of close family members. It is suggested that this investigation be maintain over time to record the personal experiences in the medium-term, adding new cases with the intention of shedding more light on the phenomenon being studied. As a preventive measure, continual workshops are needed on the proper use of respiratory protection in addition, a group of monitors is required.

• 전자공학회논문지SC
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• 제39권3호
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• pp.183-190
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• 2002

본 논문에서는 구조화된 어파인(affine) 파라미터 불확실성을 가지는 시변 선형시스템과 구조적 불확실성을 가지는 상태궤환 제어기에 대한 견실 비약성 H∞ 제어기 설계방법을 다루었다. 또한 견실 비약성 H∞ 제어기가 존재할 충분조건, 제어기 설계방법 및 비약성을 만족하는 제어기의 꽉찬 집합(compact set)을 제시하였다. 이 때 제시한 조건은 변수치환과 슈어 여수(Schur complement)정리를 통하여 선형행렬부등식 (LMI : Linear Matrix Inequality)의 계수가 꽉찬 집합 내의 파라미터의 함수로 정의되는 파라미터화 선형 행렬부등식(PLMls: parameterized Linear Matrix Inequalities)으로 표현되므로 분리 볼록개념 (separated convexity concepts)에 기초한 완화기법을 이용하여 유한개의 LMI로 변환하였다. 그리고 본론문에서 제시한 견실 비약성 H∞ 제어기가 제어기이득의 변화에도 불구하고 폐루프시스템의 점근적 안정성 (asymptotic stability)과 외란감쇠 성능을 보장함을 보였다.

• Journal of Construction Engineering and Project Management
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• 제10권1호
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• pp.16-32
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• 2020

Cost and time control of projects is important in preventing project failure. However, achieving effective cost and time control in practice is often challenging. The challenges of project cost and time control in practice are investigated by carrying out a questionnaire survey on the top 150 construction contractors in the UK followed by in-depth semi-structured interviews of practitioners from 15 construction companies in the country. Quantitative analysis reveals that design change is the most important factor inhibiting the ability of UK contractors from effectively controlling both the cost and time of construction projects. Four of the top five factors inhibiting effective cost control are also the top factors inhibiting effective time control albeit in a different order. These top factors-design changes, inaccurate evaluation of project time/duration, risk and uncertainty, non-performance of subcontractors and nominated suppliers were also found to be endogenous factors to the project. Additionally, qualitative analysis of the interviews reveals 16 key challenges to prevent for effective project cost and time control in practice. These are classified into four categorised based on where they stem from as follows; from the organisation (1. Lack of integration of cost and time during project control, 2. lack of management buy-in, 3. complicated project control systems and processes, 4. lack of a project control training regime); from the construction management/project management approach (5. Lapses in integration of interfaces, 6. project control not being implemented from the early stages of a project, 7. inefficient utilisation and control of labour, 8. limited time devoted to planning how a project will be controlled at the outset); from the client; (9. Excessive authorisation gates, 10. use of adversarial and non-collaborative forms of contracts, 11. communication problems within client set-up, 12. obstructive client representatives) and; from the project team (13. Lack of detailed/complete design, 14. lack of trust among the project partners, 15. limited time devoted to project control on site, 16. non-factual reporting). The study posits that knowledge of these project control inhibiting factors and challenges is the first step at ensuring they are avoided and enable the implementation of a more effective project cost and time control process in practice.

• Geomechanics and Engineering
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• 제8권2호
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• pp.153-171
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• 2015

The observational method in tunnel engineering allows the evaluation in real time of the actual conditions of the ground and to take measures if its behavior deviates considerably from predictions. However, it lacks a consistent and structured methodology to use the monitoring data to adapt the support system in real time. The definition of limit criteria above which adaptation is required are not defined and complex inverse analysis procedures (Rechea et al. 2008, Levasseur et al. 2010, Zentar et al. 2001, Lecampion et al. 2002, Finno and Calvello 2005, Goh 1999, Cui and Pan 2012, Deng et al. 2010, Mathew and Lehane 2013, Sharifzadeh et al. 2012, 2013) may be needed to consistently analyze the problem. In this paper a methodology for the real time adaptation of the support systems during tunneling is presented. In a first step limit criteria for displacements and stresses are proposed. The methodology uses graphics that are constructed during the project stage based on parametric calculations to assist in the process and when these graphics are not available, since it is not possible to predict every possible scenario, inverse analysis calculations are carried out. The methodology is applied to the "Bois de Peu" tunnel which is composed by two tubes with over 500 m long. High uncertainty levels existed concerning the heterogeneity of the soil and consequently in the geomechanical design parameters. The methodology was applied in four sections and the results focus on two of them. It is shown that the methodology has potential to be applied in real cases contributing for a consistent approach of a real time adaptation of the support system and highlight the importance of the existence of good quality and specific monitoring data to improve the inverse analysis procedure.

• 한국치위생학회지
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• 제18권6호
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• pp.1067-1077
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• 2018

Objectives: The purpose of the study is to investigate the opinions of some local clinical dental hygienists on medical personnel of dental hygienists. It will be for provide the Future dental hygienist basic data necessary for medical personnel. Methods: A self-reported questionnaire was completed by 171 dental hygienists in Busan and Gyeongnam from December 1, 2017 to January 31, 2018. Structured questionnaires were uesd for analysis. The questionnaire consisted of general characteristics of the subjects(7 items), medical personnel necessity and opinions of dental hygienist(2 items), the opinions of distinction of the task between dental hygienists and other personnel(2 items), many frequency task in the dental clinic. The collected data were analyzed using frequency, percentage, descriptive statistics and ANOVA using IBM SPSS VER 20.0. Results: 89.5% of the dental hygienists required medical personnel of dental hygienist, the opinions on the necessity were as follows: 'role and quality improvement as oral health professionals', 'lack of legislation and application of dental hygienists duties'. There was no difference reason between dental hygienists and other personnel on duties, the reason were investigated to uncertainty of dental hygienist system, lack of dental hygienist workforce, dentists lack awareness of dental hygienist expertise. There was surveyed by the current many frequency duties in the dental clinic, assist for dental treatment, Oral health education and counselling, Preventive dental treatment. Conclusions: Legal guarantees for clinical dental hygienists work are absolutely required. Therefore, relevant government agencies and related organizations should resolve the contradiction of the legal system of medical law and medical technicians. The clinical dental hygienists should be promoted to medical personnel through the amendment of the medical law so that the duties practiced by the dental hygienist can be matched with the legal practice.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.275-275
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• 2021

A fixed Z-R relationship approach, such as the Marshall-Palmer relationship, for an entire year and for different seasons can be problematic in cases where the relationship varies spatially and temporally throughout a region. From this perspective, this study explores the use of long-term radar reflectivity for South Korea to obtain a nationwide calibrated Z-R relationship and the associated uncertainties within a Bayesian regression framework. This study also investigates seasonal differences in the Z-R relationship and their roles in reducing systematic error. Distinct differences in the Z-R parameters in space are identified, and more importantly, an inverse relationship between the parameters is clearly identified with distinct regimes based on the seasons. A spatially structured pattern in the parameters exists, particularly parameter α for the wet season and parameter β for the dry season. A pronounced region of high values during the wet and dry seasons may be partially associated with storm movements in that season. Finally, the radar rainfall estimates through the calibrated Z-R relationship are compared with the existing Z-R relationships for estimating stratiform rainfall and convective rainfall. Overall, the radar rainfall fields based on the proposed modeling procedure are similar to the observed rainfall fields, whereas the radar rainfall fields obtained from the existing Marshall-Palmer Z-R relationship show a systematic underestimation. The obtained Z-R relationships are validated by testing the predictions on unseen radar-gauge pairs in the year 2018, in the context of cross-validation. The cross-validation results are largely similar to those in the calibration process, suggesting that the derived Z-R relationships fit the radar-gauge pairs reasonably well.

• Asia pacific journal of information systems
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• 제19권1호
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• pp.33-62
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• 2009

Internet computing is a disruptive IT innovation. Semantic Web can be considered as an IT innovation because the Semantic Web technology possesses the potential to reduce information overload and enable semantic integration, using capabilities such as semantics and machine-processability. How should organizations adopt the Semantic Web? What factors affect the adoption and diffusion of Semantic Web innovation? Most studies on adoption and diffusion of innovation use empirical analysis as a quantitative research methodology in the post-implementation stage. There is criticism that the positivist requiring theoretical rigor can sacrifice relevance to practice. Rapid advances in technology require studies relevant to practice. In particular, it is realistically impossible to conduct quantitative approach for factors affecting adoption of the Semantic Web because the Semantic Web is in its infancy. However, in an early stage of introduction of the Semantic Web, it is necessary to give a model and some guidelines and for adoption and diffusion of the technology innovation to practitioners and researchers. Thus, the purpose of this study is to present a model of adoption and diffusion of the Semantic Web and to offer propositions as guidelines for successful adoption through a qualitative research method including multiple case studies and in-depth interviews. The researcher conducted interviews with 15 people based on face-to face and 2 interviews by telephone and e-mail to collect data to saturate the categories. Nine interviews including 2 telephone interviews were from nine user organizations adopting the technology innovation and the others were from three supply organizations. Semi-structured interviews were used to collect data. The interviews were recorded on digital voice recorder memory and subsequently transcribed verbatim. 196 pages of transcripts were obtained from about 12 hours interviews. Triangulation of evidence was achieved by examining each organization website and various documents, such as brochures and white papers. The researcher read the transcripts several times and underlined core words, phrases, or sentences. Then, data analysis used the procedure of open coding, in which the researcher forms initial categories of information about the phenomenon being studied by segmenting information. QSR NVivo version 8.0 was used to categorize sentences including similar concepts. 47 categories derived from interview data were grouped into 21 categories from which six factors were named. Five factors affecting adoption of the Semantic Web were identified. The first factor is demand pull including requirements for improving search and integration services of the existing systems and for creating new services. Second, environmental conduciveness, reference models, uncertainty, technology maturity, potential business value, government sponsorship programs, promising prospects for technology demand, complexity and trialability affect the adoption of the Semantic Web from the perspective of technology push. Third, absorptive capacity is an important role of the adoption. Fourth, suppler's competence includes communication with and training for users, and absorptive capacity of supply organization. Fifth, over-expectance which results in the gap between user's expectation level and perceived benefits has a negative impact on the adoption of the Semantic Web. Finally, the factor including critical mass of ontology, budget. visible effects is identified as a determinant affecting routinization and infusion. The researcher suggested a model of adoption and diffusion of the Semantic Web, representing relationships between six factors and adoption/diffusion as dependent variables. Six propositions are derived from the adoption/diffusion model to offer some guidelines to practitioners and a research model to further studies. Proposition 1 : Demand pull has an influence on the adoption of the Semantic Web. Proposition 1-1 : The stronger the degree of requirements for improving existing services, the more successfully the Semantic Web is adopted. Proposition 1-2 : The stronger the degree of requirements for new services, the more successfully the Semantic Web is adopted. Proposition 2 : Technology push has an influence on the adoption of the Semantic Web. Proposition 2-1 : From the perceptive of user organizations, the technology push forces such as environmental conduciveness, reference models, potential business value, and government sponsorship programs have a positive impact on the adoption of the Semantic Web while uncertainty and lower technology maturity have a negative impact on its adoption. Proposition 2-2 : From the perceptive of suppliers, the technology push forces such as environmental conduciveness, reference models, potential business value, government sponsorship programs, and promising prospects for technology demand have a positive impact on the adoption of the Semantic Web while uncertainty, lower technology maturity, complexity and lower trialability have a negative impact on its adoption. Proposition 3 : The absorptive capacities such as organizational formal support systems, officer's or manager's competency analyzing technology characteristics, their passion or willingness, and top management support are positively associated with successful adoption of the Semantic Web innovation from the perceptive of user organizations. Proposition 4 : Supplier's competence has a positive impact on the absorptive capacities of user organizations and technology push forces. Proposition 5 : The greater the gap of expectation between users and suppliers, the later the Semantic Web is adopted. Proposition 6 : The post-adoption activities such as budget allocation, reaching critical mass, and sharing ontology to offer sustainable services are positively associated with successful routinization and infusion of the Semantic Web innovation from the perceptive of user organizations.