• Journal of Radiation Protection and Research
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• 제24권3호
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• pp.131-142
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• 1999

통계청에서 최근에 발표한 한국인 인구통계 자료와 미국 학술원 산하 '방사선의 생물학적 영향 위원회'의 최근 보고서(BEIR-V)의 수정 상대위험 투사모델을 적용하여 한국인의 방사선 피폭에 의한 초과 암발생 위험도를 평가하였다. 인구통계 자료로부터 유도한 사소위험도(trivial risk) 및 계산된 방사선유발 초과 암 위험도를 비교한 후 사소위험도의 수준으로 개인의 피폭선량을 유지하기 위한 국내 원전의 안전운영 목표치를 유도하였다. 방사선 피폭 유발 초과 암 위험도는 0.1 Gy의 단일피폭의 경우에는 $5.5{\times}10^{-3}$, 1.0 mGy/y로 생애연속 피폭 시엔 $3.7{\times}10^{-3}$인 것으로 평가되었다. 한국인의 모든 원인에 의한 기저사망 위험도 및 사소위험도는 각각 $5.2{\times}10^{-3}$ 및 $5.2{\times}10^{-6}$인 것으로 예상되었다. 한국인의 사소위험도 및 방사선 위험도 평가 결과로부터 유도한 국내 원전운영의 안전목표치는 대략 0.05 mSv/y로, 이 값은 미국 원자력규제위원회(USNRC)가 연방규제법 10CFR50 부록 I에서 제시하고 있는 ALARA 지침값과 거의 동일한 값으로 밝혀졌다.

• 산업경영시스템학회지
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• 제44권1호
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• pp.1-8
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• 2021

As a nation experiencing rapid economic growth, South Korea and its government have made a continuous effort toward efficient research investments to achieve transformation of the Korean industry for the fourth industrial revolution. To achieve the maximum effectiveness of the research investments, it is necessary to evaluate its funding's worth and default risk. Thus, incorporating the concepts of the Black-Scholes-Merton model and the Greeks, this study develops a default-risk evaluation model in the foundation of a system dynamics methodology. By utilizing the proposed model, this study estimates the monetary worth and the default risks of research funding in the public and private sectors of Information and Communication technologies, along with the sensitivity of the R&D economic worth of research funding to changes in a given parameter. This study finds that the public sector has more potential than the private sector in terms of monetary worth and that the default risks of three types of research funding are relatively high. Through a sensitivity analysis, the results indicate that uncertainty in volatility, operation period, and a risk-free interest rate has trivial impacts on the monetary worth of research funding, while volatility has large impacts on the default risk among the uncertain factors.

• Journal of Construction Engineering and Project Management
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• 제8권1호
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• pp.10-21
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• 2018

Many construction projects involve a plethora of safety-related problems that can cause loss of productivity, diminished revenue, time overruns, and legal challenges. Incorporating data collection and analytics methods can help overcome the root causes of many such problems. However, in a dynamic construction workplace collecting data from a large number of resources is not a trivial task and can be costly, while many contractors lack the motivation to incorporate technology in their activities. In this research, an Android-based mobile application, Preemptive Construction Site Safety (PCS2) is developed and tested for real-time location tracking, trajectory prediction, and prevention of potential collisions between workers and site hazards. PCS2 uses ubiquitous mobile technology (smartphones) for positional data collection, and a robust trajectory prediction technique that couples hidden Markov model (HMM) with risk-taking behavior modeling. The effectiveness of PCS2 is evaluated in field experiments where impending collisions are predicted and safety alerts are generated with enough lead time for the user. With further improvement in interface design and underlying mathematical models, PCS2 will have practical benefits in large scale multi-agent construction worksites by significantly reducing the likelihood of proximity-related accidents between workers and equipment.

• International Journal of Safety
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• 제10권2호
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• pp.21-26
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• 2011

In 2001, an independent official board was constituted in Japan to investigate aircraft and railway accidents. In the past 10 years, many accidents and serious incidents have been investigated and these official reports were published by the board, on which the author had sat for 9 years as boarding member. In the interim, there were several train disasters which mocked our trust in railways and also many apparent trivial incidents. In recent years, serious incidents, which a door of running rail cars opens suddenly with some trouble, happen 2 or 3 times in a year. For the past 10 years, such incidents have happened 14 times and 13 cases of them were closed by the board mentioned above. In these 13 cases, no one fell off the rail car, so that the death toll was none luckily. In this paper, these 13 serious incidents are picked up among all the reports published by the board and outlined using some tables. Especially, fall accidents of passengers are discussed mainly from the view point of impact force and duration time. Then, the equation of HIC (Head Injury Criteria) and the risk curves in terms of the HIC are dealt with properly.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.65-68
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• 2000

The problem of selecting a portfolio is to find Un investment plan that achieves a desired return while minimizing the risk involved. One stream of algorithms are based upon mixed integer linear programming models and guarantee an integer optimal solution. But these algorithms require too much time to apply to real problems. Another stream of algorithms are fur a near optimal solution and are fast enough. But, these also have a weakness in that the solution generated can't be guaranteed to be integer values. Since it is not a trivial job to tansform the scullion into integer valued one simutaneously maintaining the quality of the solution, they are not easy to apply to real world portfolio selection. To tackle the problem more efficiently, we propose an algorithm which generates a very good integer solution in reasonable amount of time. The algorithm is tested using Korean stock market data to verify its accuracy and efficiency.

• Journal of Korean Neurosurgical Society
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• 제53권3호
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• pp.201-203
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• 2013

In most cases, subdural hematoma (SDH) is regarded as a complication of head injury and nontraumatic causes are rare. Moreover, spontaneous chronic SDH in child or adolescent is very unusual. Here, we present the case of a healthy 14-year-old girl who was diagnosed as a spontaneous chronic SDH. The patient presented with severe headache following blurring of vision two weeks ago without any history of trivial head injury. Computed tomography and magnetic resonance imaging depicted a chronic SDH. The cause of the hematoma was not established. After performing burr hole drainage of the hematoma, the patient made an uneventful recovery. We explore the potential risk factors and pathophysiology implicated in this condition. Possible pathogenic mechanisms of this unique case are discussed and a review of the pertinent literature is included.

• Journal of Radiation Protection and Research
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• 제12권2호
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• pp.37-50
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• 1987

The exposure of the population in the United States to ionizing radiation has recently been evaluated by the National Council on Radiation Protection and Measurements (NCRP). This was done by constituting six organizational groups to address various phases of the work and the results of this work are summarized in this article. The article is based on the report, by the same title, which is scheduled for publication by the NCRP in September, 1987. The six organizational groups are titled Radiation Exposure from Consumer Products, Natural Background Radiation, Radiation Associated with Medical Examinations, Radiation Received by Radiation Employees, Public Exposure from Nuclear Power, and Exposure from Miscellaneous Environmental Sources. These titles are descriptive of the subject areas covered by each of these separate groups. The data evaluated are for the years 1977-1984 with the majority of the data being for the period 1980-1982. Summary information is presented and discussed for the number of people exposed to given sources, the effective dose equivalent, the average effective dose equivalent to the U.S. population, and the genetically significant dose equivalent. The average annual effective dose equivalent from all sources to the U.S. population is approximately 3.6 mSv (360 mrem). Exposures to natural sources make the largest contribution to this total. Radon and radon decay products contribute 2.0 mSv (200 mrem) whereas the other naturally occurring radionuclides contribute 1.0 mSv (100 mrem). Among man-made or enhanced sources, medical exposures make the largest additional contributions, namely 0.39 mSv (39 mrem) for diagnosis and 0.14 mSv (14 mrem) for nuclear medicine. It was not possible to evaluate exposures for therapy. Most of the other sources of population exposure, including nuclear power and consumer products, are minor. A possible exception would be the use of tobacco products. These exposures are discussed in relation to a negligible individual risk level of $10{\mu}Sv/y$ (1 mrem/y). The NCRP considers exposures below the negligible individual risk level as trivial and as such should be dismissed.

• Journal of Chest Surgery
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• 제42권5호
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• pp.597-603
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• 2009

배경: 기능적 단심 실에서 방실판막 폐쇄부전은 폰탄수술 후 사망과 그 만기성적의 중요한 위험인자로 알려져 있다. 단심실의 공통방실판 페쇄부전에 대한 이분성형술(bivavaltion valvuloplasty)의 중단기 성적을 조사하였다. 대상 및 방법: 1999년부터 2007년까지 판막 이분성형술을 시행한 기능적 단심실 환자 11명을 대상으로 하였다. 공통방실판 역류의 정도는 color Doppler 심초음파로 결정하였다 (경미(trivial); 1, 경도(mild); 2, 중등도(moderate); 3, 고도(severe); 4). 판막 수술 당시 평균 나이는 생후 $6.9{\pm}7.0$개월(중간 값 4개월, 범위 24일$\sim$21개월)이었고 평균 체중은 $6.2{\pm}2.8\;kg$ (범위: $3.1{\sim}11.3\;kg$)이었다. 9명의 환자가 심방이형증(atrial isomerism)을 갖고 있었으며 이 중 두 명은 총폐정맥연결 이상을 동반하였다. 1예를 제외한 모든 예에서 동시에 다른 수술이 함께 시행되었다. 판막 이분성형술 이외에 같이 시행된 판막 술식은 3예에서 교련봉합술, 또 다른 3예에서 교련부 판륜성형술을 시행하였다. 결과: 병원사망이 1예 있었는데 술 전 인공호흡이 필요하였던 생후 32일된 환아로, 폐동맥교약술과 함께 판막 이분성형술을 시행한 후 4.3개월에 기도와 폐 질환으로 사망하였다. 평균 추적기간은 40개월(범위: $4.3{\sim}114$개월)이었다. 평균 수술 전 공통방실판 역류는 $3.3{\pm}0.6$이었고 이는 수슬 후 $1.9{\pm}0.7$로 개선되었다(p<0.0001). 이 잔존 역류는 평균 14.3개월 후 $2.2{\pm}0.4$로 조금 증가하였으나 통계학적 유의성은 없었다. 6명(60%)의 환아에서 잔존 역류로 인해 양방성 상공정맥-폐동맥 단락술이나 폰탄수술 시에 판막에 대한 재수술이 필요하였다. 1예는 우측 방실판막에 엡스타인기형 형태를 갖고 있었던 환아로 방실판 협착 및 역류로 인해 판막치 환술을 시행하였다. 다른 1명의 환아는 우측 방실판막에 가장자리 봉합술(edge-to-edge technique)을 시행하였으며 나머지 4명의 환아에게는 전후 브리징판엽(bridging leaflet)사이에 봉합을 추가하였다. 모든 환자에서 마지막 추적 초음파에서 경미 혹은 경도의 역류를 보였다. 결론: 기능적 단심실의 공통판막 역류에서 판막 이분성형 술은 효과적이고 안전한 술식이다. 그러나 많은 환자에서 잔존 역류를 가지고 있었으며 반수 이상의 환자에서 다음 단계의 수술에서 판막의 재수술이 필요하다 공통판 역류의 진행에 대한 장기적 추적조사가 꼭 필요할 것으로 생각된다.

• 한국안전학회지
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• 제37권3호
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• pp.52-59
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• 2022

Conventionally, all the unsafe acts by human beings in relation to industrial accidents have been regarded as unintentional human errors. Exceptionally, however, in the cases with fatalities, seriously injured workers, and/or losses that evoked social issues, attention was paid to violating related laws and regulations for finding out some people to be prosecuted and given judicial punishments. As Heinrich stated, injury or loss in an accident is quite a random variable, so it can be unfair to utilize it as a criterion for prosecution or punishment. The present study was conducted to comprehend how categorizing intentional violations in unsafe acts might disrupt conventional conclusions about the industrial accident process. It was also intended to seek out the right direction for countermeasures by examining unsafe acts comprehensively rather than limiting the analysis to human errors only. In an analysis of 150 industrial accident cases that caused fatalities and featured relatively clear accident scenarios, the results showed that only 36.0% (54 cases) of the workers recognized the situation they confronted as risky, out of which 29.6% (16 cases) thought of the risk as trivial. In addition, even when the risks were recognized, most workers attempted to solve the hazardous situations in ways that violated rules or regulations. If analyzed with a focus on human errors, accidents can be attributed to personal deviations. However, if considered with an emphasis on safety rules or regulations, the focus will naturally move to the question of whether the workers intentionally violated them or not. As a consequence, failure of managerial efforts may be highlighted. Therefore, it was concluded that management should consider unsafe acts comprehensively, with violations included in principle, during accident investigations and the development of countermeasures to prevent future accidents.

• 벤처창업연구
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• 제9권4호
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• pp.77-85
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• 2014

청소년을 대상으로 진행되는 창업교육의 목적은 성공적인 창업을 위한 창업구성요소의 개별적인 훈련보다는 창업이라는 프로세스를 이해하고 기업가정신을 함양하며 창의성을 향상시키는데 있다. 교육의 효과는 창업에 대한 올바른 인식을 심어주며 창업저변을 확대할 수 있는 가능성을 만들어 준다. 따라서 창업교육프로그램을 수강한 학생들이 교육을 통하여 어떠한 영향을 받았는지에 대한 검증은 매우 중요하며 이러한 효과측정을 통하여 더 나은 교육프로그램을 개발할 수 있는 계기를 마련할 수 있다. 그럼에도 불구하고 창업교육프로그램에 대한 효과성 측정도구에 대해서는 아직 연구가 미진한 상태이다. 따라서 창업교육프로그램을 통한 효과에 대한 정의와 이를 측정할 수 있는 지표의 개발이 필요하다. 본 연구에서는 이론적 경험적 접근방법을 통해 청소년의 창업교육프로그램을 통해 체화될 수 있는 학습효과를 기업가지향성, 창의성, 창업준비행동 등의 3개영역과 11개의 하위영역으로 구분하고 효과측정을 위한 49개의 예비문항을 도출하였다. 도출된 항목을 비즈쿨 선정학교인 5개의 특성화고등학교 학생 287명을 표본으로 실중분석을 실시하였다. 탐색적 요인분석과 확인적 요인분석을 통해 최종 3개영역, 8개의 하위영역(혁신성, 위험감수성, 문제해결능력, 협력적 의사결정, 효율적 행동능력, 정보수집, 진로탐색, 창업탐색 및 준비), 38개의 측정문항을 확정하였고, 마지막으로 척도의 신뢰도를 확보함으로써 최종의 청소년 창업교육프로그램 효과성 측정항목을 완성하였다. 추가적으로 비즈쿨 대상의 학생중에서 적극적으로 창업교육프로그램에 참여하고 있는 창업동아리 참여자와 비참여자와의 효과성에 대한 평균값을 비교한 것과 9개의 측정지표에 차이가 있음을 볼 수 있었다.