• Journal of Chest Surgery
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• v.31 no.12
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• pp.1165-1171
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• 1998

Background: All currently available mechanical and bioprosthetic valves are associated with various types of deterioration leading to dysfunction and/or valvular complications. Reoperation on prosthetic heart valves is increasingly under consideration for both clinical and prophylactic indications. This review was conducted to determine the factors affecting the risk of reoperation for prosthetic valve replacement. Material and method: From January 1985 to July 1996, 124 patients underwent reoperation on prosthetic heart valves, and 3 patients had a second valve reoperation. The causes of reoperation were prosthetic valve failure(96 cases, 77.4%), prosthetic valve thrombosis(16 cases, 12.9%), prosthetic valve endocarditis(7 cases, 5.6%) and paravalvular leak(5 cases, 4.1%). This article is based on the analysis of the experience with particular emphasis on the preoperative risks affecting the outcome of the reoperation. Result: Overall hospital mortality rate was 8.9%(11/124). Low cardiac output was the most common cause of death(70.6%). Left ventricular systolic dimension(p=0.001), New York Heart Association functional class IV(p=0.003) and serum creatinine level(p=0.007) were the independent risk factors, but age, sex and cardiothoracic ratio did not have any influence on the operative mortality. Follow-up period was ranged from 3 to 141 months (mean, 50.6 months). A late mortality rate was 1.8%. Conclusion: The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, therefore reoperation is recommended before the hemodynamic impairment become severe.

• Journal of Global Scholars of Marketing Science
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• v.17 no.1
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• pp.101-122
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• 2007

Recently, as internet shopping mall users rapidly, a form of shopping changed from off line to on line. The rapid growth of customers and transaction volume through evolution of new media, internet, brings new problems to internet marketers. It is the most important task that how internet shopping mall operators obtain their customers trust and repeat buying. This empirical research investigates online shoppers for their trust dimensions for online retailers. The study aimed to determine whether e-trust antecedents(perceived reputation, perceived quality, perceived value) influence trust dimension and whether the multidimensional trust contributed differently to perceived risk and willingness to depend on e-retailers. Consequences of the research are as follows: First, it reveals that of reputation, web site quality of the internet shopping mall have influence upon trust dimension. Second, the higher level of trust consumers have, the higher level of willingness to depend and intent to revisit on the retailers they have. But level of perceive risk consumers have not influences on willingness to depend on the retailers. It is necessary for internet shopping mall to development its reputation and familiarity to obtain customer's trust. Accordingly, this research will be helping internet shopping mall insight for marketing strategies, constantly should study about action and mind of consumer.

• Fire Science and Engineering
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• v.33 no.5
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• pp.94-102
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• 2019

As the importance of first responses for fire accidents has grown in the safety management of nuclear power plants, a systematic approach to measure firefighters' psychological states and competence is needed. The current study investigated the construct of the risk perception of the firefighters working near nuclear power plant sites, and then developed and validated a new scale to measure firefighters' risk perception regarding nuclear power plant accidents. The scale items were developed on the basis of literature review and interviews with the firefighters working near nuclear power plant sites. In order to validate the new scale, we recruited 180 firefighters from five fire stations in the vicinity of the nuclear power plants in Jeonnam Province, Gyeongbuk Province, and Busan. The results of exploratory factor analyses revealed that the scale consisted of five factors: "manual" reflecting a lack of response guidelines and manuals for fire incidents and radioactive material release; "fear" reflecting a fear of fire incidents in the nuclear power plants and their catastrophic consequences; "resource" reflecting a lack of protective equipment and manpower for responding to fire incidents in the nuclear power plants; "trust" reflecting trust and cooperation with the counterpart institutions for firefighting in the nuclear power plants; and "knowledge" reflecting the knowledge of radioactivity and firefighting in the nuclear power plants. Further analyses provided statistical evidence supporting for the 15-item scale's internal consistency and construct validity. Finally, We discussed the implication and limitations of the current research.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.15-20
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• 2009

The purpose of this study was to investigate behavior to protect medical record among physical therapists(PTs). This study conducted a survey through the self-written questionnaires from 69 clinical PTs to understanding to protect patient' medical record. The result indicated that the behavior of PTs was not average 1, but the older PTs and healthier PTs, more protective patient's medical record(p<.01). The revision of PTs' behavior attitude and intention subjective was helpful to improve their behavior to protect patent's medical record.

• Journal of Hydrogen and New Energy
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• v.28 no.2
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• pp.166-173
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• 2017

For commercialization of hydrogen refuelling station (HRS), we need to reduce the clearance distance for jet fire in the real entities in the HRS. Thus, we revisited the current regulations of clearance distance for jet fire in the law. The law in korea has been set up by replica of japan, not by our own scientific basis. Recently, sandia lab developed Hydrogen Risk Assessment Model (HyRAM) tools and we simulated a series of circumstances such as 10 to 850 bar with several leak hole sizes. In 850 bar with 10 mm diameter hole leak cases, it shows $4,981kW/m^2$ at 12 m separation from leak source and $1,774kW/m^2$ at 17 m separation from leak source. In 850 bar with 1 mm diameter leak hole, it shows $0.102kW/m^2$ at 12 m separation and $0.044kW/m^2$ at 17 m separation. Current law may be acceptable with 1 mm hole size with 850 bar.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.678-682
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• 2003

Video-assisted thoracoscopic surgery is good indication of secondary spontaneous pneumothorax. This method usually required general anesthesia and single-lung ventilation with collapse of other lung. But, risks of general anesthesia and single-lung ventilation must be considered in high-risk patients. Material and Method: Between September f999 and August 2001, 15 high-risk patients were treated by video-assisted thoracoscopic surgery under epidural anesthesia. Result: Video assisted thoracoscopic surgery was successfully performed in 15 patients. Duration of postoperative air-leakage was 4.3days, Significance of complication was none, No recurrence of pneumothorax was encountered. Conclusion: Video-assisted thoracoscopic surgery can be performed safely under epidural anesthesia for treatment of secondary spontaneous pneumothorax in high-risk patients.

• Journal of the Korean Institute of Gas
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• v.10 no.1 s.30
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• pp.48-55
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• 2006

In order to establish the comprehensively, quantitatively predictable program to the fire and explosion accidents in the urban gas system, and to set up domestic criteria of societal risk, the collected urban gas accident data have been deeply analyzed. The Poisson probability distribution functions with t=5 for the database of the gas accidents in recent 11 year shows that 'careless work-explosion-pipeline' item has the lowest frequency, whereas 'joint loosening & erosion-release-pipeline' item has the highest frequency. And thus the proper counteractions must be carried out. The further works requires setting up successive database on the fire and explosion accidents systematically to obtain reliable analyses.

• Journal of Korean Institute of Fire Investigation
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• v.11 no.1
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• pp.1-8
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• 2008

The purpose of this paper is to report gas fire accident based on classification of the major gas fire causes (including handling mistakes, inferior goods, etc.), fire classifications (fire, explosion, leakages, etc.), damage levels(1st, 2nd, 3rd, 4th grade levels), casualties (death, serious wound, slight injury) since gas fire has been generated according to growth of gaseous fuel consumption on home and enterprises with various accident causes. Among gaseous fuels, LPG facility can be c1assified as gas container, pressure regulator, gas hose, interim valve, combustion port. Any fire or any explosion can be caused from handling mistakes, inferior goods on each parts as stated above. Exact gas fire causes shall be identified based on previous case studies on similar fires with consideration of lesson learns.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.32-38
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• 2016

In general, lots of containers including various dangerous materials are transported to the port located in big cities such as Busan where massive residents live. Thus, it's really important how to make the emergency response for the leak accidents of dangerous materials and evaluate the direct or indirect damages to adjacent areas. In this study, in order to make reasonable emergency plans, CA (Consequence Analysis) is employed after selecting a key hazardous and noxious material, hydrogen fluroide. This material accounts for the third largest portion of cargo volume among all dangerous materials and can cause a huge damage in case of leakages. As a case study, Busan North port is selected as a test port since the portion of dangerous materials is higher than that of other ports in Busan. It is assumed that 1 ton of hydrogen fluoride is spilled at Busan North port. CA is performed to assess the impact of this accident. Throughout CA, the ERPG-2 range of a leak accident can be evaluated and this result can be used for decision making tools for mitigating the impact of a leak accident. To mitigate the damage of this accident, suitable a protective equipment and resident evacuation procedures should be prepared. Finally, this study can provide a systematic approach to make the emergency plan for reducing economical and personal losses.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.109-112
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• 2012

원자력발전소는 타 산업시설에 비해 화재발생 가능성이 낮으나 방사성물질 누출가능성을 최소화하기 위하여 심층방어와 다중방호 설계를 통한 안전성확보가 매우 중요하다. 이를 위해 국내에서는 화재위험도분석(FHA)과 안전정지능력분석(SSA) 및 화재 확률론적안전성분석(Fire PSA)을 수행하고 있으며, 이 중 화재 PSA는 주요 화재구역 선별, 구역별 화재발생빈도 및 기기손상확률 계산, 화재사고 경위분석 및 화재취약성 파악 등을 분석한다. 본 논문에서는 미국 원자력규제위원회(USNRC)와 전력연구소(EPRI)가 공동 연구개발한 화재 PSA 방법론인 NUREG/CR-6850 기법을 적용하여, 화재 PSA에 필요한 화재점화빈도(Fire Ignition Frequency)를 정량적으로 계산하였다. 정확한 결과값을 도출하기 위해 매크로를 이용한 프로그램인 FIFA(Fire Ignition Frequency Analyzer)를 개발하였으며, 향후 국내 원전 화재 PSA 분석업무에 유용하게 사용될 수 있을 것으로 기대된다.