• Journal of Communications and Networks
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• v.16 no.6
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• pp.667-676
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• 2014

Connectivity is a crucial quality of service measure in wireless sensor networks. However, the network is always at risk of being split into several disconnected components owing to the sensor failures caused by various factors. To handle the connectivity problem, this paper introduces an in-advance mechanism to prevent network partitioning in the initial deployment phase. The approach is implemented in a distributed manner, and every node only needs to know local information of its 1-hop neighbors, which makes the approach scalable to large networks. The goal of the proposed mechanism is twofold. First, critical nodes are locally detected by the critical node detection (CND) algorithm based on the concept of maximal simplicial complex, and backups are arranged to tolerate their failures. Second, under a greedy rule, topological holes within the maximal simplicial complex as another potential risk to the network connectivity are patched step by step. Finally, we demonstrate the effectiveness of the proposed algorithm through simulation experiments.

• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.37-47
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• 2002

Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment ＆ measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.1-11
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• 2010

Establishing a framework, to explain the path to safety accidents considering major safety management factors such as physical conditions including on-site activities and workplace, as well as human factors as to labor, supervisors, or managers, would be effective as the basis to control project's risks by preventing disasters. Therefore, this study aimed to clarify the mechanism in safety management and disaster occurrence. In order to accomplish the purpose, it identified and classified the factors related to accidents, reviewed the causal relationships among them, and suggested the influence diagram. The results of this research are expected to contribute to reinforcing the preventive management, and facilitating the development of integrated site control system based on safety risks.

• Computers and Concrete
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• v.31 no.3
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• pp.185-195
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• 2023

Antalya is located south part of minor Asia, one of the biggest cities in Türkiye. As a result of population growth and vast migration to Antalya, many parts of the city that were not suitable for construction due to its geological conditions have become urban areas, and most of these urban areas are full of poorly engineered buildings. Poor engineering has been combined with unplanned urbanization, that causes utter vulnerability to disasters in Antalya. When an earthquake-prone city, Antalya faces with an earthquake risk, fear arises in society. To overcome this problem, it has become necessary to investigate the building stock, expressed in hundreds of thousands, in a fast and reliable way and then perform an urban transformation to create the perception of structural safety. However, the excessive building stock, labor, and economic problems made the implementation stage challenging and revealed the necessity of finding alternative solutions in the field. The present study presents a novel approach for assessment and model based on a rapid visual inspection method to transform areas under earthquake risk in Türkiye. The approach aimed to rank the interventions for decision-making mechanisms by making comparisons in the scale hierarchy. In the present study, to investigate the proposed approach, over 26,000 buildings were examined in Antalya, which is the fifth largest city in Türkiye that has a population of over 2.5 Million. In the results of the study, the risk classification was defined in the framework of building, block, street, neighborhood, and district scales.

• The Journal of Industrial Distribution & Business
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• v.11 no.3
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• pp.7-17
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• 2020

Purpose: This study reexamines the test on the pricing of accruals quality. Theory suggests that information risk is a priced risk factor. Using accruals quality as the proxy for information risk, researchers have tested the pricing of information risk. The results are inconsistent potentially because of the information shock in the realized returns that are used as the proxy for expected returns. Based on this argument, this study revisits this issue excluding information-shock-free measure of expected returns. Research design, data and methodology: This study estimates expected returns using the vector autoregression model. This method extracts information shocks more thoroughly than the methods in prior studies; therefore, the concern regarding information shock is minimized. As risk premiums are larger in recession periods than in expansion periods, recession and expansion subsamples were used to confirm the robustness of the main findings. For the pricing test, this study uses two-stage cross-sectional regression. Results: Empirical results find evidence that accruals quality is a priced risk factor. Furthermore, this study finds that the pricing of accruals quality is observed only in recession periods. Conclusions: This study supports the argument that accruals quality, as well as the pricing of information risk, is a priced risk factor.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.61-74
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• 2004

Risk analysis model is systematic and structural process that considers internal security problems and threat factors of the information systems to find optimal level of security control. But, the risk analysis model is just only defined conceptually and there are not so many empirical studies. This research used structural equation modeling(SEM) research methodology with rigorously validated research instrument. Based on results of this study, risk analysis methodology was proved to be practically useful in e-commerce environment. Factors like threat and control were significantly related to risk. In conclusion, the results of this study can be applied to general situation or environment of information security for analyzing and managing the risk and providing new approach to comprehend concept of risk in e-commerce environment.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.729-733
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• 2011

The maritime risk assessment is important not only to evaluate the safety level of the ports and waterways but also to reduce potential maritime accidents at sea in terms of the proactive measures of the maritime accidents. In this paper, the collision risk assessment in Mokpo waterways has been carried out based on the IALA recommended model, IWRAP. To evaluate the accident probabilities in Mokpo waterways, all data of vessels were collected from AIS and Radar observations data and the computer simulations were carried out. To assess the risk on the traffic, the scenario-base approach has been applied to the Mokpo waterway by using the maritime accident statics over the past 5 years.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.3
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• pp.125-135
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• 2017

The paper considers the practical application of the FMEA(Failure Mode and Effect Analysis) method to assess the operational reliability of the LNG(Liquefied Natural Gas) transfer system, which is a potential problem for the connection between the LNG FPSO and LNG carrier. Hazard Identification (HAZID) and Hazard operability (HAZOP) are applied to identify the risks and hazards during the operation of LNG transfer system. The approach is performed for the FMEA to assess the reliability based on the detection of defects typical to LNG transfer system. FTA and FMEA associated with a probabilistic risk database to the operation scenarios are applied to assess the risk. After providing an outline of the safety assessment procedure for the operational problems of system, safety assessment example is presented, providing details on the fault tree of operational accident, safety assessment, and risk measures.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.334-346
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• 2005

The purpose of this paper is to introduce the concept of worst practice DEA, which aims at identifying worst performers by placing them on the efficient frontier. This is particularly relevant for our application to credit risk evaluation, but this also has general relevance since the worst performers are where the largest improvement potential can be found. The paper also proposes to use a layering technique instead of the traditional cut-off point approach, since this enables incorporation of risk attitudes and risk-based pricing. Finally, it is shown how the use of a combination of normal and worst practice DEA models enable detection of self-identifiers. The results of the empirical application on credit risk evaluation validate the method which is proposed in this paper.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2101-2107
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• 2008

This study has proposed the development procedure of 'railway accident risk assessment model' by as a common approach. The risk assessment procedure is following the requirements of the common safety methods (CSM) suggested in EU and was developed based on the accident scenarios. Various hazardous events, which have the potential to lead directly to casualties, were defined. Then, for each hazardous event, the railway accident appearance scenarios and railway accident progress scenarios were developed. The developed procedure will provide a generic model of the safety risk on the Korea railway.