• Title/Summary/Keyword: severe incident

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Simulation and Damage Analysis of an Accidental Jet Fire in a High-Pressure Compressed Pump Shelter

  • Jang, Chang Bong;Choi, Sang-Won
    • Safety and Health at Work
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    • v.8 no.1
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    • pp.42-48
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    • 2017
  • Background: As one of the most frequently occurring accidents in a chemical plant, a fire accident may occur at any place where transfer or handling of combustible materials is routinely performed. Methods: In particular, a jet fire incident in a chemical plant operated under high pressure may bring severe damage. To review this event numerically, Computational Fluid Dynamics methodology was used to simulate a jet fire at a pipe of a compressor under high pressure. Results: For jet fire simulation, the Kemeleon FireEx Code was used, and results of this simulation showed that a structure and installations located within the shelter of a compressor received serious damage. Conclusion: The results confirmed that a jet fire may create a domino effect that could cause an accident aside from the secondary chemical accident.

Design and evaluation of laser module for light delivery in heat assisted magnetic recording (열 보조 자기기록용 광 전달 레이저 모듈의 설계 및 평가)

  • Choi, Yong-Bok;Lee, Moon-Ho;Kim, Young-Joo
    • Transactions of the Society of Information Storage Systems
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    • v.7 no.1
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    • pp.36-41
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    • 2011
  • The micro laser module was designed and prepared to deliver the light to the HAMR head. It consists of laser diode, photo diode and actuator to realize stable light delivery even though the head is fluctuated during the disk rotation. The optical evaluation was carried out with the actual distance between the light source and HAMR head with a range of reflectivity and it was found that the incident angle could be controlled within ${\pm}0.125^{\circ}$ to maintain same intensity into the HAMR head. It was also confirmed that the designed micro laser module is thermally stable without any severe effect on the magnetic head.

The Influence of CEO's Scandal on Consumers' Product Purchase

  • CHOI, Ji-Eun
    • The Journal of Industrial Distribution & Business
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    • v.11 no.4
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    • pp.47-56
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    • 2020
  • Purpose: This study aims to explore how consumers respond to the immoral actions of a CEO. More specifically, this research focuses on the moral reasoning processes used by consumers in order to maintain support for the CEO despite the immoral action. In addition, this research suggests that support for the CEO would improve product purchase intention. Research design, data, and methodology: To test the hypotheses presented, an online research company was hired and online survey was conducted with adult participants. Online research company sent an email to the potential subjects asking their participation in an online survey. Subjects were able to participate in the online survey by clicking a link to the survey. When the participants clicked the link, they were instructed to read a fictitious newspaper article on a CEO's immoral action. And then, they were asked to answer several questions online. Responses were obtained from 336 adults participants and data were analyzed using SPSS Hayes Macro for a moderation effect and AMOS for a structural equation model. Result: Moral reasoning processes were divided into moral decoupling and moral rationalization and analyzed to determine their influence on product purchase. Also in this study, we suggest the public self-consciousness of consumers as an antecedent of moral reasoning processes, and argue that consumers with high public self-consciousness are more likely to engage in moral decoupling than moral rationalization. Conclusions: Our results showed that moral decoupling and moral rationalization improved the consumer's perception of corporate ethicality, which increased product purchase intention. In addition, consumers with high public self-consciousness were more likely to engage in moral decoupling than in moral rationalization. In addition, this research suggested that severity of the scandal would moderate the impact of public self-consciousness on moral decoupling. However, this hypothesis was not supported statistically since most participants perceived the scandal to be a highly severe incident, that may lead to an insignificant interaction effect between severity of the scandal and public self-consciousness. This research expands the scope of available research on corporate ethics and consumer responses to negative information involving celebrities and provides practical implications for corporate crisis management.

A Study on Categorization of Accident Pattern for Organization's Information Security Strategy Establish (기업 정보보안 전략 수립을 위한 보안 사고 유형 분류에 관한 연구)

  • Kim, Hee-Ohl;Baek, Dong-Hyun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.193-201
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    • 2015
  • Corporation's valuable intelligent asset is being threatened from the skills of threatening subject that has been evolved along with the growth of the information system and the amount of the information asset. Domestically, attempts of various private information attacks, important information extortion, and information damage have been detected, and some of them have abused the vulnerability of security of information system, and have become a severe social problem that generates security incident. When accessing to the security, most of companies used to establish a strategy with a consistent manner and a solution plan. However, this is not a proper way. The order of priorities vary depending on the types of business. Also, the scale of damage varies significantly depending on the types of security incidents. And method of reaction and critical control point vary depending on the types of business and security incidents. In this study, I will define the security incidents by their types and preponderantly examine how one should react to those security incidents. In this study, analyzed many types of security accidents that can occur within a corporation and an organization considering various factors. Through this analysis, thought about factors that has to be considered by corporations and organizations when they intend to access to the information security. This study focuses on the response methodology based on the analysis of the case analysis of the leakage of industrial secret and private secret other than the conceptual response methodology that examines the way to prevent the leakage of the industry security systems and the industry information activities. And based on these factors, want to be of help for corporations to apply a reasonable approach when they establish a strategy to information security.

An Approximation Method in Bayesian Prediction of Nuclear Power Plant Accidents (원자력 발전소 사고의 근사적인 베이지안 예측기법)

  • Yang, Hee-Joong
    • Journal of Korean Institute of Industrial Engineers
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    • v.16 no.2
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    • pp.135-147
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    • 1990
  • A nuclear power plant can be viewed as a large complex man-machine system where high system reliability is obtained by ensuring that sub-systems are designed to operate at a very high level of performance. The chance of severe accident involving at least partial core-melt is very low but once it happens the consequence is very catastrophic. The prediction of risk in low probability, high-risk incidents must be examined in the contest of general engineering knowledge and operational experience. Engineering knowledge forms part of the prior information that must be quantified and then updated by statistical evidence gathered from operational experience. Recently, Bayesian procedures have been used to estimate rate of accident and to predict future risks. The Bayesian procedure has advantages in that it efficiently incorporates experts opinions and, if properly applied, it adaptively updates the model parameters such as the rate or probability of accidents. But at the same time it has the disadvantages of computational complexity. The predictive distribution for the time to next incident can not always be expected to end up with a nice closed form even with conjugate priors. Thus we often encounter a numerical integration problem with high dimensions to obtain a predictive distribution, which is practically unsolvable for a model that involves many parameters. In order to circumvent this difficulty, we propose a method of approximation that essentially breaks down a problem involving many integrations into several repetitive steps so that each step involves only a small number of integrations.

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Subspace-Based Adaptive Beamforming with Off-Diagonal Elements (비 대각요소를 이용한 부공간에서의 적응 빔 형성 기법)

  • Choi Yang-Ho;Eom Jae-Hyuck
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1A
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    • pp.84-92
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    • 2004
  • Eigenstructure-based adaptive beamfoming has advantages of fast convergence and the insentivity to errors in the arrival angle of the desired signal. Eigen-decomposing the sample matrix to extract a basis for the Sl (signal plus interference) subspace, however, is very computationally expensive. In this paper, we present a simple subspace based beamforming which utilizes off-diagonal elements of the sample matrix to estimate the Sl subspace. The outputs of overlapped subarrays are combined to produce the final adaptive output, which improves SINR (signal-to-interference-plus-noise ratio) comapred to exploiting a single subarray. The proposed adaptive beamformer, which employs an efficient angle estimation is very roubust to errors in both the arrival angles and the number of the incident signals, while the eigenstructure-based beamforer suffers from severe performance degradation.

Barotraumatic Rupture of The Esophagus -A Case Report- (압력 상해에 의한 식도파열 -1례보고-)

  • 이해영
    • Journal of Chest Surgery
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    • v.27 no.4
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    • pp.331-334
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    • 1994
  • Pneumatic rupture is a rare cause of esophageal injury, as evidenced by only 19 cases reported in the literature. We experienced one case of esophageal rupture due to bursting of a truck inner tube. The patient, who was a 45-year old male, had severe chest pain, respiratory distress, flushing in the face and neck, and subcutaneous emphysema after tire explosion. Three days after the incident, a diagnosis of rupture of the thoracic esophagus was established by esophagogram using water soluble contrast media, and then emergency operation was done. The operation involved mediastinal and thoracic drainage and resection of the esophagus combined with cervical esophagostomy and feeding gastrostomy. On the 105th day after the operation, cervical esophagogastrostomy via substernal route was performed. The patient was successfully treated with the staged operations. As in the other reported cases, the injury was located in the lower one third of the esophagus. Four main characteristics of the clinical signs of pneumatic rupture are 1] wounds or burns to the face or mouth, 2] chest pain or epigastric pain, 3] subcutaneous emphysema, and 4] respiratory distress. We emphasize that the high index of suspicion of esophageal rupture is very important in diagnosis and that diagnosis should be based on the same findings common to other forms of esophageal injury.

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Analysis of seismic mid-column pounding between low rise buildings with unequal heights

  • Jiang, Shan;Zhai, Changhai;Zhang, Chunwei;Ning, Ning
    • Earthquakes and Structures
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    • v.15 no.4
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    • pp.395-402
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    • 2018
  • Floor location of adjacent buildings may be different in terms of height elevation, and thus, the slab may hit on the columns of adjacent insufficiently separated buildings during severe ground motions. Such impacts, often referred to as mid-column pounding, can be catastrophic. Substantial pounding damage or even total collapse of structures was often observed in large amount of adjacent low rise buildings. The research on the mid-column pounding between low rise buildings is in urgency need. In present study, the responses of two adjacent low rise buildings with unequal heights and different dynamic properties have been analyzed. Parametric studies have also been conducted to assess the influence of story height difference, gap distance and input direction of ground motion on the effect of structural pounding response. Another emphasis of this study is to analyze the near-fault effect, which is important for the structures located in the near-fault area. The analysis results show that collisions exhibit significant influence on the local shear force response of the column suffering impact. Because of asymmetric configuration of systems, the structural seismic behavior is distinct by varying the incident directions of the ground motions. Results also show that near-fault earthquakes induced ground motions can cause more significant effect on the pounding responses.

The Measurement of Dose Distribution in the Presence of Air Cavity and Underdosing Effect Result from Lack of Electronic Equilibrium (조사면 내 공동의 존재에 따른 선량분포의 변화측정)

  • Cho, Jung-Hee
    • Journal of radiological science and technology
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    • v.19 no.1
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    • pp.81-87
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    • 1996
  • When high energy photon beam is incident upon an air cavity interface the effect of ionization build-up observed. This phenomenon is resulting from the surface layers of the lesions are significant deficiency of electrons reaching the layers because of the replacement of solid scattering material by the air cavity, that is lack of electronic equilibrium. Measurement have been made in an acrylic phantom with a parallel plate chamber and high energy Photon beams, CO-60, 4MV, 6MV and 10MV X-rays have been investigated. The result of our study show that a significant effect was measured and was determined to be very dependent on field size, air cavity dimension and photon energy. The reductions were much larger for 10MV beam, underdosage at the interface was 12, 12.2, 16.9 and 20.6% for the CO-60, 4 MV, 6MV and 10MV, respectively. It was found that this non-equilibrium effect at the interface is more severe for the higher energy beams than that of lower energy beams and the larger cavity dimensions it is, the larger beam reductions we have. This problem is of clinical concern when lesions such as carcinoma beyond air cavities are irradiated, such as larynx, glottic and the patients with maxillectomy and ethmoidectomy and so forth.

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Effect of Infra-Gravity Waves on Nearshore Morphodynamics in the East Coast : Case Study - Ilsan Beach (장주기 중력외파의 동해안 연안지형변화에 미치는 영향 연구 : 사례연구 - 일산해변)

  • Son, Donghwi;Yoo, Jeseon;Shin, Hyunhwa
    • Ocean and Polar Research
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    • v.40 no.2
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    • pp.87-98
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    • 2018
  • It is widely known that infragravity waves can exert significant influence on wave run-up over beaches. Large run-ups can lead to overwash, flooding and severe coastal erosion. In spite of the importance of infragravity waves in relation to wave run-up and coastal erosion, few studies have been carried out with regard to the impact of infragravity waves on nearshore morphodynamics with respect to eastern beaches in Korea. The purpose of this study is to investigate the importance of infragravity waves in nearshore numerical modelling. For the study, XBeach model was set up to analyze morphodynamics in December 2016, in Ilsan beach which is located in Ilsan-dong, Ulsan Metropolitan City. After validation of the XBeach model, numerical experiments were conducted by using various directional spreading coefficients. As the directional spreading coefficients are increased, the effect of infragravity waves is also enhanced by narrowband frequency. With the increasing effect of infragravity waves, the amount of sediment transport is also increased and an erosion dominant pattern is found in the south part of Ilsan beach and a deposition pattern in the north part of the beach mainly due to the wave incident direction of NNE.