• Journal of Gastric Cancer
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• 제12권2호
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• pp.88-98
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• 2012

Purpose: Local recurrence, due to residual tumor, may occur after endoscopic resection for early gastric cancer. The aims of this study are to evaluate the predictive factors for local recurrence, and suggest an appropriate follow-up biopsy strategy. Materials and Methods: We retrospectively reviewed 396 early gastric cancers from 372 consecutive patients, who underwent endoscopic resection between January 2002 and April 2008. Cumulative recurrence rates were determined by the Kaplan-Meier method, and Cox proportional hazard analysis was used to determine the risk factors for local recurrence. Results: Local recurrence at the endoscopic resection site was found in 17 cases, among the total 396 lesions, during a median follow-up period of 48 months. The 5-year cumulative local recurrence rate was 4.8%. Multivariate analyses determined that tumor involvement at the lateral resection margin [hazard ratio: 35.9; P<0.001], uncheckable lateral resection margin [hazard ratio: 16.8; P<0.001], uncheckable or involved deep resection margin [hazard ratio: 3.76; P=0.047], and piecemeal resection [hazard ratio: 3.95; P=0.007] were associated with local recurrence. If a lesion was positive for any of these risk factors, the 5-year cumulative recurrence rate was 27.0%, while local recurrence was not found in any lesion that lacked these risk factors. Most episodes of recurrence were found during the first or second follow-up endoscopic biopsy at the ulcer scar. Conclusions: Routine follow-up biopsies at the endoscopic resection site might be unnecessary in cases where an early gastric cancer lesion was endoscopically resected en bloc with tumor-free lateral and deep margins.

• 한국화재소방학회논문지
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• 제10권4호
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• pp.29-36
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• 1996

건축물 화재로 인한 인적, 물적 피해를 방지하기 위하여는 먼저 이들 시설, 설비에 존재하는 잠재위험요인을 찾아내고 위험이 얼마나 큰가를 분석하는 위험성 평가가 수행되어야 한다. 본 연구에서는 건물의 화재 위험성을 822개의 Checklist에 의해 평가하도록 하였으며, 정량적 평가를 위하여 주요 구성 요소를 10개의 대분류로 나누고, 가중치를 부여하여 100점 만점의 점수를 산출하도록 하였다. 건물의 실제평가를 통하여 평가 모델의 적정성을 검토한 결과, 본 모델은 일반 모든 건물에 대하여 평가 적용이 가능하도록 되었다. 또한 Checklist에 의한 세부적인 질문기법으로 작성되어 건물의 화재 위험성 평가를 수월하게 수행할 수 있도록 하였다. 따라서 본 평가모델의 제시는 이제까지 국내에서 소방진단을 위한 뚜렷한 평가모델이 마련되지 못한 현시점에서 방화관리자 등 소방관련자에게 매우 유익한 평가모델이 될 것이다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1294-1301
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• 2010

In this study, a case study, where a hazard management for tunnel collapses has been quantitatively undertaken based on the KICT Tunnel Hazard(KTH) index, is presented. From this, it was able to timely inform the field engineers when the more detailed investigation is required for checking if any risky factor is shown on the tunnel face. At the same time, variable additional information such as sensitivities of major influence factors are also provided to field engineers from the methodology given in this study. The additional information would be helpful for better understanding of tunnel hazard level at the current tunnelling stage and following the required actions for more detailed checks of risky factors.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.232-238
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• 2011

Hazard analysis provides the basic foundation for system safety. Hazard analysis is performed to identify hazards, hazard effects, and hazard causal factors. Hazard analysis is used to determine system risk, to determine the significance of hazards, and to establish design measures that will eliminate or mitigate the identified hazards. Hazard analysis is used to systematically examine systems, subsystems, facilities, components, software, personnel, and their interrelationships, with consideration given to logistics, training, maintenance, test, modification, and operational environments. This paper present hazard analysis techniques which is commonly used in railway signalling, comparised their benefits and limitations.

• 해양환경안전학회지
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• 제22권3호
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• pp.278-285
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• 2016

The key features of maritime accidents are the change of their attributes by new risks from time to time. To prevent maritime accidents in Korea, the impacts by new risks on domestic safety environments should be identified or predicted. The purpose of this paper is to find the hazard factors by new risks on maritime safety in Korea. The meaning of new risks is the elements of accident hazard which is compiled from new or rare or unprecedented events in the worldwide maritime transportations. The problems of new risks are the lacks of optimum countermeasures to mitigate accident risks. Using the questionnaires with 152 event scenarios classified by 20 accident causes, the hazard identification and risk analysis of new risks was performed based on the Formal Safety Assessment (FSA) by IMO. A total of 22 Influence Diagrams, which is to depict the transit flows between accident causes to consequences, is used in the construction of 152 event scenarios. A total of 20 accidents causes is the same contents as the causation factors represented in Statistical Year Book for Maritime Accidents of Korean Maritime Safety Tribunals. After defining the evaluation equations to the response results of questionnaires by 46 experts, the work for risk analysis is carried out. As results from the analysis of 152 scenarios, it is known that the root cause to affect on maritime safety in Korea is the pressure of business competition and it led to the lacks of well experienced crews, the overload of vessel operations and crew's fatigue. In addition, as results from the analysis of 20 accident causes, the three accident causes are to be candidate as main issues in Korea such as the inadequate preparedness of departure, the neglecting of watch keeping in bridge and the inadequate management of ship operations. All of the results are thought to be as basic hazard factors to safety impediments. It is thus found that the optimum Risk Control Options to remove the hazard factors and to mitigate consequences required are the following two factors: business competition and crewing problems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.2116-2120
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• 2008

Recently, in the national railway industry there has been interested in the methodology of hazard analysis and risk assessment. The need of safety management system based on the technology of hazard analysis and risk assessment is being extended to identify in advance the weakness and threat factors causing the accident and cope with the accident actively. It is important to manage the risk of railway casualty accidents having a majority of railway accident. Especially, a hazard event of people struck takes the highest proportion of the railway casualty accidents. This paper describes the result of analysis for environment properties such as an age of casualty, time happened, day, month and weather conditions being concerned in the hazard event of people struck.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.202-205
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• 2006

The objective of this study is to analyze the hazard-areas for landslide using GIS and RS. LRA (Logistic Regression Analysis) and AHP (Analytic Hierarchy Program) methods were used for evaluation of the hazard-areas by six topographic factors (slope, aspect, elevation, soil drain, soil depth, land use). These methods were applied to Anseong-si where frequent landslides were occurred mainly by the regional heavy rainfall. A landslide hazard-map of Anseong-si could describe into 7 hazard-grades. As results, LRA method was underestimated in higher grades areas, while AHP method was underestimated in lower grades areas. In order to evaluate the hazard-areas for landslides with accuracy, these results of each method were overlapped and the results of suggested method were compared with the historical landslide hazard records of KFRI (Korea Forest Research Institute).

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1-6
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• 2005

To improve safety management of railway and cope with the factors to threat technical and social safety, we need to establish railway safety management system based on analysis of hazards and assessment of risk for railway system. So we have to conduct PHA(Preliminary Hazard Analysis) first to understand weak points and factors to possibly threat safety using analysis of related data such as past accident/incident data and safety regulation and classification standards of hazards/causes of railway accidents. Therefore in this research, we led types/dangerous events/causes of risks/factors of risks from hazard log developed based on railway accident classification and hazards of railway accident. PHA model for domestic railway system will be used in risk analysis and risk assessment of railway accident.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6773-6777
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• 2015

We used to LASSO-Cox method for determining prognostic factors of male breast cancer survival and showed the superiority of this method compared to Cox proportional hazard model in low sample size setting. In order to identify and estimate exactly the relative hazard of the most important factors effective for the survival duration of male breast cancer, the LASSO-Cox method has been used. Our data includes the information of male breast cancer patients in Fars province, south of Iran, from 1989 to 2008. Cox proportional hazard and LASSO-Cox models were fitted for 20 classified variables. To reduce the impact of missing data, the multiple imputation method was used 20 times through the Markov chain Mont Carlo method and the results were combined with Rubin's rules. In 50 patients, the age at diagnosis was 59.6 (SD=12.8) years with a minimum of 34 and maximum of 84 years and the mean of survival time was 62 months. Three, 5 and 10 year survival were 92%, 77% and 26%, respectively. Using the LASSO-Cox method led to eliminating 8 low effect variables and also decreased the standard error by 2.5 to 7 times. The relative efficiency of LASSO-Cox method compared with the Cox proportional hazard method was calculated as 22.39. The19 years follow of male breast cancer patients show that the age, having a history of alcohol use, nipple discharge, laterality, histological grade and duration of symptoms were the most important variables that have played an effective role in the patient's survival. In such situations, estimating the coefficients by LASSO-Cox method will be more efficient than the Cox's proportional hazard method.

• 한국항행학회논문지
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• 제28권1호
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• pp.87-94
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• 2024

항공산업의 발전에도 불구하고 조종사의 인적오류에 의한 항공기 사고는 지속해서 발생하고 있다. 인적오류에 의한 항공기 사고의 원인은 비행안전을 저해하는 위해(hazard) 요인을 사전에 제거하지 못해 사고로 이어지는 것이다. 본 연구는 국내 항공사에 근무하는 운항승무원과 일반항공 (general aviation)의 조종사를 대상으로, 비행안전을 위협하는 여러 가지 위해 요인 중에서 조종사에게 심리적, 신체적으로 영향을 미치는 직무스트레스와 피로, 불안감이 안전행동에는 어떠한 영향을 미치는지 살펴보았다. 아울러 직무스트레스와 안전행동의 간에 안전문화의 매개효과를 확인하기 위한 실증분석을 실시하였다. 연구 결과에 의하면 직무스트레스는 조종사의 안전행동에 직접적인 영향을 줄 뿐만이 아니라 안전분위기, 보고문화와 같은 항공사의 안전문화에도 영향을 미친다는 것이다. 이러한 조종사의 직무스트레스와 안전문화, 안전행동간의 상관관계를 통해 안전관리시스템의 성과를 제고하고자 한다.