• 한국의류학회지
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• 제41권4호
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• pp.771-781
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• 2017

The helmet is an imperative personal protective equipment. This protective device must be able to guard the human head against potential risks. Helmets are classified according into the purpose of use; therefore, the required performance and specifications depend on the type of products. Military helmets are intended to protect the wearer's head from bullets and shrapnel. Generally, lightweight super fibers and fiber reinforced composite materials are used as helmet shell materials, and NIJ STD of U.S. Department of Justice is most widely used as international standard related to bulletproof helmets. Safety helmets are widely used for industrial application and sports leisure. In general, the performance of shock absorption must be ensured, and various lining systems are applied in material, design, and combination methods. Evaluation standards have also been classified and strictly controlled for each purpose; therefore, it is difficult to certify with the existing standards such as the recently developed convergence helmets. However, it is possible to launch the product through a separate national integrated certification procedure.

• 한국식품영양과학회지
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• 제28권1호
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• pp.199-204
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• 1999

This study has attempted to examine the effect of Artemisia iwayomogi extract on antioxidant and liver function related enzymes in rats fed high fat diet along with B( )P administration. The activities of the serum glutamic oxaloacetic transaminase, glutamic pyruvate transaminase and alkaline phosphatase of the rats fed Artemisia iwayomogi ethanol extract were decreased compared to the control. Similarily, the activities of the enzymes were also decreased when the combination of B( )P and ethanol extracts were administered compared to the group adminstered only B( )P. On the other hand, high fat diet increased the above liver function related enzymes. The activities of antioxidant enzymes including GST, catalase and Cu,Zn SOD were significantly increased by feeding the extracts (p<0.01) in addition to the increase of tocopherol contents in the serum. These results suggest that Artemisia iwayomogi extracts can protect cell membranes from the damages by free radicals or hydroperoxides and further may lead to the protection from cancer risks.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.922-928
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• 2016

Bearing in mind that global climate change is a rising issue, the coastal community of Prek Thnaot, Cambodia has been put on severe effects about natural disasters caused from poor infrastructure and agriculture dependence. This paper proposes to provide and guide a strategic action for the sustainable development path of coastal community in a more continuous manner including a robust resilience to impacts of climate change, natural disasters, and other risks. In doing so, this paper will help environmentally sound management and coastal resources sustainability being sound for socially and economically inclusive development. Proposed fourteen strategic actions for the research should be accompanying with the participation of and cooperation from the local coastal community. Based on the proposed strategic actions, it is critical that the local authorities and other key stakeholders need to accomplish. Providing a good insight for the central government, the strategic action is expected to integrate and prepare a management strategy plan for the local coastal community level. Therefore, this information can be applied to other coastal areas to promote and ensure sustainable protection and management of coastal resources.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제36권3호
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• pp.116-123
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• 2014

Purpose: The purpose of this study was to evaluate risks for wound dehiscence after guided bone regeneration (GBR) in dental implant surgery. Methods: Patients who received dental implant therapy with GBR procedure at Seoul National University Bundang Hospital (Seongnam, Korea) from June 2004 to May 2007 were included. The clinical outcome of interest was complications related to dental implant surgery. The factors influencing wound dehiscence, classified into patient-related factors, surgery-related factors and material-related factors, were evaluated. Results: One hundred and fifteen cases (202 implants) were included in this study. Wound dehiscence (19.1%) was considered a major complication. The risk of wound dehiscence was higher in males than in females (odds ratio=4.279, P =0.014). In the main graft, the allogenic group had the lowest risk of wound dehiscence (odds ratio=0.106, P =0.006). Though the external connection group had a higher risk of wound dehiscence than the internal connection group (odds ratio=2.381), the difference was not significant (P =0.100). Conclusion: In this study, male gender and main graft have the highest risk of wound dehiscence. To reduce wound dehiscence after GBR, instructions on postoperative care with supplementary procedure for the protection of the wound dehiscence is recommended, especially to male patients. A main graft with a gel base can reduce the risk of wound dehiscence.

• 경영과정보연구
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• 제4권
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• pp.309-325
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• 2000

Organizations rely on Secure ID resources today to handle vast amounts of information. Because the data can vary widely in type and in degree of sensitivity, employees need to be able to exercise flexibility in handling and protecting it. It would not be practical or cost-effective to require that all data be handled in the same manner or be subject to the same protection requirements. Without some degree of standardization, however inconsistencies can develop at introduce risks. Policy formulation is an important step toward standardization of security activities for ID resources. ID security policy is generally formulated from the input of many members of an organization, including security officials, line managers, and ID resource specialists. However, policy is ultimately approved and issued by the organization's senior management. In environments where employees feel inundated with policies, directives, guidelines and procedures, an ID security policy should be introduced in a manner that ensures that management's unqualified support is clear. The organization's policy is management's vehicle for emphasizing the commitment to ID security and making clear the expectations for employee involvement and accountability. This paper will discuss ID security Policy in terms of the different types (program-level and issue-specific), components, and Implementation of Expert System Simulation based on 4GL, PowerBuilder.

• 한국환경과학회지
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• 제16권3호
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• pp.247-253
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• 2007

Polycyclic aromatic hydrocarbons (PAHs) are a major concern because of their potential mutagenic and carcinogenic risks to human beings. One of these harmful, yet commonly observed PAHs is pyrene. Pyrene is one of the 16 PAHs listed by the United States Environmental Protection Agency as priority pollutants. The purposes of this research are to develop a method of pretreatment for PAH contaminants prior to a typical biological treatment and to demonstrate the biodegradablity of these compounds. Since pyrene is non-polar, hexane was chosen as a solvent to effectively dissolve pyrene. Pyrene solutions were treated with ozone, as it has hish oxidation capacity and electrophilic character. The intermediates and byproducts of pyrene were dissolved in alkaline water at pH 11.4 and neutralized to test for $BOD_5$, COD, and toxicity. These solutions were further ozonated and assessed of biodegradability. The first-order rate constant to was found to be between $0.121day^{-1}$ and $0.081 day^{-1}$, depending on the duration of reozonation. The $BOD_5/COD$ ratio was found to 0.66. The toxicity test showed that after 10 min of reozonation time, the byproducts and intermediates of pyrene were within the lion-toxic range of ${\pm}10%$ inhibition for E-Coli bacteria.

• 한국항해항만학회지
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• 제41권5호
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• pp.287-296
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• 2017

The Formal Safety Assessment (FSA) is a structured and systematic methodology developed by the IMO, aimed at assessing the risk of vessels and recommending the method to control intolerable risks, thereby enhancing maritime safety, including protection of life, health, the marine environment and property, by using risk analysis and cost-benefit assessment. While the FSA has mostly been applied to merchant vessels, it has rarely been applied to a DP vessel, which is one of the special purpose vessels in the offshore industry. Furthermore, most of the FSA has been conducted so far by using the Fault Tree Analysis tool, even though there are many other risk analysis tools. This study carried out the FSA for safe operation of DP vessels by using the Bayesian network, under which conditional probability was examined. This study determined the frequency and severity of DP LOP incidents reported to the IMCA from 2001 to 2010, and obtained the Risk Index by applying the Bayesian network. Then, the Risk Control Options (RCOs) were identified through an expert brainstorming and DP vessel simulations. This study recommends duplication of PRS, regardless of the DP class and PRS type and DP system specific training. Finally, this study verified that the Bayesian network and DP simulator can also serve as an effective tool for FSA implementation.

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.517-524
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• 2017

Cyber security is an important issue in the field of nuclear engineering because nuclear facilities use digital equipment and digital systems that can lead to serious hazards in the event of an accident. Regulatory agencies worldwide have announced guidelines for cyber security related to nuclear issues, including U.S. NRC Regulatory Guide 5.71. It is important to evaluate cyber security risk in accordance with these regulatory guides. In this study, we propose a cyber security risk evaluation model for nuclear instrumentation and control systems using a Bayesian network and event trees. As it is difficult to perform penetration tests on the systems, the evaluation model can inform research on cyber threats to cyber security systems for nuclear facilities through the use of prior and posterior information and backpropagation calculations. Furthermore, we suggest a methodology for the application of analytical results from the Bayesian network model to an event tree model, which is a probabilistic safety assessment method. The proposed method will provide insight into safety and cyber security risks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3671-3689
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• 2019

Software defined networking brings unique security risks such as control plane saturation attack while enhancing the performance of wireless sensor networks. The attack is a new type of distributed denial of service (DDoS) attack, which is easy to launch. However, it is difficult to detect and hard to defend. In response to this, the attack threat model is discussed firstly, and then a DDoS attack prevention extension, called FuzzyGuard, is proposed. In FuzzyGuard, a control network with both the protection of data flow and the convergence of attack flow is constructed in the data plane by using the idea of independent routing control flow. Then, the attack detection is implemented by fuzzy inference method to output the current security state of the network. Different probabilistic suppression modes are adopted subsequently to deal with the attack flow to cost-effectively reduce the impact of the attack on the network. The prototype is implemented on SDN-WISE and the simulation experiment is carried out. The evaluation results show that FuzzyGuard could effectively protect the normal forwarding of data flow in the attacked state and has a good defensive effect on the control plane saturation attack with lower resource requirements.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.111-120
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• 2021

Takaful, which is an Islamic insurance instrument, manages risks in business, according to Shariah (Islamic law) principles and offers risk protection and savings assets. The study analyzes the comparative efficiency of takaful insurance companies by implementing empirical research. The study also provides a comprehensive literature review on the efficiency analysis of the takaful industry. The empirical part presents a wide range of efficiency comparisons of 41 takaful insurance companies in 16 countries between 2009 and 2014. The data enveloping analysis technique is utilized using the rDEA package in the R environment to compute the efficiency score. In the study, the technical efficiency, overall technical efficiency, and pure technical efficiency are calculated and compared per year and per country. The findings of the study suggest that the overall average efficiency scores of takaful companies are considerably high. The study results also indicate that the excess in the consumption of inputs decreases while the deficit in achieved outputs has been declining in the covered period. The study suggests the managers of the takaful companies can use the target efficiency scores, which are calculated by using the DEA analysis, as an ideal reference benchmark for planning their inputs and outputs.