• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.835-842
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• 2009

The present thesis carried out a research on a compression pressure's reduction phenomenon and its countermeasure according to the thermal efficiency improvement method by a Miller method in 4-cycle low speed diesel engine. In case of retardation of intake valve closing time in a engine, the theoretical heat efficiency shows a remarkably reducing trend when a compression ratio is not compensated. Accordingly, the thermal efficiency showed an increasing trend in case of compensating the compression ratio. Especially, it could be understood that the theoretical heat efficiency at near ABDC $100^{\circ}$ of intake valve closing time in case of compensation of the compression ratio was improved by around 25.1%, and the mean effective pressure was also increased by around 18.6%. Also, as the retardation of intake valve closing time increases, air quantity becomes insufficient due to a backflow phenomenon of intake air and thus thermal efficiency was decreased in a high load operation domain. The solving method of this problem is possible by supercharge. Therefore, in order to improve thermal efficiency by retardation of ntake valve closing time, the thermal efficiency improvement according to low compression is possible when there are a compensation device of a compression ratio and a supercharge device. This is a problem-solving method of low compression and high expansion cycle.

• The Journal of Sustainable Design and Educational Environment Research
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• v.17 no.2
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• pp.22-37
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• 2018

This study suggests desirable disaster safety education curriculum through analyzing the operational status of the school disaster safety management training course and demand survey of school staff. First, the problem of the disaster safety training course of the school is not connected with the lack of law and system and the school disaster safety job. Second, improvement of law and system and variety of training should be made to acquire professional knowledge. Third, it is necessary to divide curriculum into the following four categories, according to educational needs of public officials ; Educational administration officers course focused on facility safety, maintenance and disaster countermeasure. Educational officials in technical post course addressing approval and permission of school facility projects, seismic reinforcement of school building, etc. Educational supervisors course covering roles and responsibilities of the school safety supervisors in the event of disaster. Teaching staffs course focused on safety instructions for students. Fourth, it is found that lectures and experiential learning methods are the most desirable methods of teaching and learning, and the major ranks are earthquake disaster, fire, gas, typhoon, school road, and electrical safety.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.91-97
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• 2011

The weight of elderly people in Korea has been increasing. Statistics show that the percentage of the elderly people in Korea was 3.1% in 1970; 3.8% in 1980; 5.1% in 1990, and 7.2% in 2000. Based on this trend, thus, the number of elderly people could be estimated to be 14% of the whole Korean population in 2018. This reveals that Korea is entering a super-aging society with remarkable fast pace. In such a change, the statistics related to elderly people driving license and the occurrence of traffic accidents are showing a noticeable numerical value. The number of traffic accident fatality in Korea ranks the highest value in OECD Countries. However, the research on old drivers in the nation is going on partially centering on system improvement and management scheme. Thus, first of all, researches about the linkage & characteristics between the driving behavior of old drivers and traffic accident should be implemented, in order properly to draw system improvement and management scheme for the old drivers. Therefore, the focus of this study is the influence model for discerning the severity of the age-old-caused traffic accidents by inquiring into the relation between the Driving Aptitude Test items that make it possible to measure their behavioral characteristics and influential factors by age group on the basis of the data on traffic accidents. The analysis results can be used as basic data for suggesting the behavioral research and countermeasure for traffic safety and its management for old driver in preparation for the aging society.

• KIEAE Journal
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• v.7 no.5
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• pp.93-98
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• 2007

Effort has been performed for latest 20 years to improve resident's comfort and indoor environment in building. And interest and effort to improve indoor air environment among various indoor environment elements have continuously increased since 1990s, because it is examined scientifically that various contaminants generated indoor affect human body. Specially, indoor air contaminants generated from apartments are those exhausted from resident's indoor environment, closing materials and household. Indoor air environment in buildings is different according to pollution degree, existence availability of pollution source, ventilation amount, and meteorology. It is known that other contaminants more than about 900 kinds generate according to a kind of work or action in a room. Specially, nowadays buildings are well insulated and confidentiality-centered for environment protection and economical side. So indoor air contaminants are generated from indoor air pollution sauces of unprepared ventilation, human body carbon dioxide emissions, and various building materials. when these are accumulated in long term human body, it is harmful to resident's health, but awareness for this is very insufficient. Because bedroom is space that people inhabit for a long time by unconscious state and indoor environment occupies important part for resident's health and quality of life at sleep, the actual condition of air quality is investigated, improvement countermeasure is considered, and ventilation amount is analyzed. In this study, putting case that the most longest stayed time is sleeping time when people inhabit in the apartment, the air quality according to volume of bedroom space at sleep was measured and analyzed, and the data acquired will be the basis for improvement on this.

• Journal of the Korea Safety Management & Science
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• v.24 no.4
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• pp.85-93
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• 2022

Today's customer service providers, who have the greatest impact on customer satisfaction, are experiencing severe stress and job burnout due to various causes. Unlike general companies, the corporation has a relatively high level of dissatisfaction with customer service since there is a large conflict between the provision of kindness and the reasonable handling of civil complaints according to laws and regulations. In order to analyze the environment of the NPS' customer service providers, 5.583 branch employees working at the National Pension Service and 407 call center employees were surveyed online using the questionnaire function of the Enterprise resource planning system. The contents of the survey consisted of a survey on customer-facing employees, the level of awareness of customer-facing workers protection measures, and opinions on improvement and supplementation related to customer-facing workers protection measures. As a result of the survey, 72.8% of the total respondents experienced grievance complaints, and the proportion of call center employees was even higher at 89.0%. In addition, both the branch and the call center had the largest share of complaints about obstruction of business, unreasonable demands, abusive language, and verbal abuse. More than 40% of call center employees in their 20s and 30s experienced the highest frequency of complaints 13 or more times a year. The most difficult thing in the process of responding to complaints was that both branch offices and call centers had insufficient psychological recovery time, lack of space, and lack of help from colleagues and superiors. Based on the survey analysis, it is suggested to establish a countermeasure through case analysis rather than the right to suspend work for civil complaints that cannot be handled, such as customized manuals and action strategies for the age group with high grievance complaints.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.111-119
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• 2012

In this study, the effect of safety improvement project was analyzed, and a decision making model for traffic accident reduction measures was suggested. The results of this study are as follow; First the overall number of traffic accidents and casualties were reduced, especially reduced the number of unauthorized crossing and centerline encroachments was remarkable. Second, the priorities of traffic accident reduction measures. through hazards roadway section improvement projects were determined. As, higher level evaluation items of AHP hierachy structure include civil facilities and transportation facilities. The civil facilities has 6 lower level evaluation items and transportation facilities has 4 items. The results of this study, It was revealed that traffic experts prefer civil facilities more than transportation facilities and the top 2 items of the each data (or index) took over 50%. In addition, one of the last evaluation contents through the verification, the top 3 items of civil facilities took 55.38%. The project according to the improvement projects for hazards roadway reduced traffic accidents and casualties as well as saving the cost. So these results should be available for basic information for the countermeasure about reducing the traffic accidents by local governments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.185-194
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• 2018

This study investigates the limitations of blockchain technology and the ways to improve it by using Delphi technique. Limit factors and improvement measures are classified into technology, service, and legal system. First, from a technical point of view, lack of standardization of the technology, insufficiency of integration, lack of scalability, unclear cancellation or correction policy, excessive cost of transaction verification, insufficient personal information protection and not enough to respond to hacking defense were the limiting factors. In order to improve these, the followings; ensuring standardization, securing integration and scalability, establishing cancellation of each applicable data, establishment of correction policy, efficiency of verification cost, the protection of personal information and countermeasure against hacking are provided. The related technology development and countermeasures must be established to effectively introduce the blockchain technology to the market. Second, in the early stage of blockchain service, it showed lack of utilization of the blockchain, security threat, shortage of skilled workers, and lack of legal liability. As a solution to these problems, it is necessary to suggest various applications, against security threat, training professional manpower, and securing legal responsibility. It should also provide a foundation for providing institutionally stable services. Third, from as legal system point of view, inadequate legal compliance, lack of relevant regulation, and uncertainty in the regulation were the limiting factors. Therefore establishing a legal system, which is the most important area for activating the service, should be accompanied by the provision of legal countermeasures, clearness of regulations and measures to be taken by relevant governmental authorities. This study will contribute as a reference for a research, related to the blockchain.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.358-366
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• 2019

Purpose: This paper aims to clarify the problems and to examine the improvement methods by investigating the management condition of local-designated cultural property of which management is relatively poor in comparison with state-designated cultural heritage. Method: In order to grasp the management situation of the local-designated cultural heritage, a research on cultural heritage management situation and problems will be carried out with 35 cultual heritages in Goryeong-gun. Also, the improvement methods about the property type vulnerability on the basis of interview with cultual property managers, fire-fighting officers and civil servants, etc. Results: Local cultural heritages were investigated to be very vulnerable to the fire of wooden buildings, the theft of movable cultural heritages, and the effects of wind and water damage. It is because cultural heritages are scattered over wide areas fundamentally. As the result, it has difficulty in the patrols of police officers and fire fighters, and in the situation that it lacks disaster monitoring and CCTV for countermeasures to replace them, electronic security including fire hydrant, sensors, etc and fire extinguishing facilities and so on. It is difficult for local governments managing local-designated cultural heritages to enhance their management systems directly due to their lack of budget and manpower. Conclusion: In order to strengthen disaster and safety management system for the cultural heritages designated by local governments, they have to clarify disaster countermeasure task of fire fighting, police, and cultural heritage managers prepare their manuals, and systematize them through disaster drill mainly in local autonomous governments. Also, so as to establish a surveillance system every day, they have to enhance the community for local cultural heritage manage consisting of local volunteer fire departments, local voluntary disaster prevention organizations, volunteers, etc.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.81-92
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• 2008

As the process of the Korea is highly industrialization and knowledge information the extent of fire fighting business is getting wide with the development and change. But work environment is not improved much compared with the past. For the situation that threaten life is exposed greatly, compared with the other profession there are also much stress. Moreover, the professional stress of fire official influence not only the safety of fire official. In this paper based on the reduction countermeasure for professional stress of fire official the following are proposed: Lively communication activity between constituents, application of people system as a result work field, improvement of treatment and welfare institution, safety of fire official and health rule enactment, the establishment of specialty hospital for fire fighting and appointment of fire medical specialist.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.5 no.1
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• pp.3-12
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• 1994

We have proposed the optimum threshold detection(OTD) technique of 16 QAM signal in the Rician fading channel and analyzed its error performance with and without the selective combining(SC) diversity technique. And we compared the error performance of OTD with that of conventional threshold detection(CTD). Having the SC diveresity reception, optimum threshold detection(OTD) technique proposed in this paper provides the performance improvement of 1.8~3.2 [dB] in CNR for fading depth K values ranging from 5 to 30 over CTD when the error rate is $10_5$. From the result of numerical analysis, we know that the proposed OTD technique is superior to CTD technique in the Rician fading channel and adoption of the SC diversity technique with the proposed OTD can be considered as a good countermeasure for the Rician fading.