• Korean Security Journal
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• no.60
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• pp.283-302
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• 2019

This study was conducted to provide the basic data for improving the working environment and welfare level of the security guard by identifying the primary effects of stress response on fatigue with emotional labor and identifying the adjustment effects with coping strategy. The data were collected from 214 security personnel using questionnaire and the statistical tests of correlation, heavy return analysis and hierarchical return analysis using the SPSS 18.0 statistics program were used to reach the conclusion that: First, it has been shown that the emotional labor of a security guard affects fatigue Second, the effects of emotional labor on fatigue of a security guard have been shown to have the effect of coping strategy. Based on the above studies, it was concluded that the emotional labor of a security guard was affected by fatigue and could be controlled by a stress coping strategy. Therefore, it is believed that there is a need to seek an autonomous corporate culture based on the organization's performance by changing the management system for employees at the organizational level so that security guards can use an active way of coping.

• Korean Security Journal
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• no.60
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• pp.9-31
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• 2019

Due to the development of technology and popularization of drone, the so-called "dirty drone" that exploits drones for crimes and terrorism has become a social problem, and it is time to seriously consider the "revenge of drones." Indeed, the cases of threats posed by drones are expanding not only to threats to ground facilities, but also to aviation safety threats, more recently to large-scale events, demonstrations and crimes targeting specific personnel, and terrorism. This research clearly defined the concept of anti-drone when it emerged as a new type of social safety threat as it was abused in crime and terrorism, while response to it was not enough yet. Through this process, it was intended to present an effective anti-drones system. We analyzed the major controversial elements of anti-drone, and defined them as "comprehensive response activities at the legal, institutional and technical levels performed by law enforcement agencies, related technology and industrial entities in a way that prevents, detects, and blocks acts that violate public well-being and order, such as crimes and terrorism caused by the drones." To effectively respond to dirty drones, the authority of law enforcement agencies and the enactment of relevant laws were proposed. In the future, a comprehensive and systematic follow-up study of the anti system should be conducted.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.3
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• pp.27-37
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• 1997

The paper deals with the effectiveness of various special rudders on course stability of a ship. We adopted five types of rudder, such as one normal rudder and four special rudders, which contain two rudders with concave and convex strips on sides respectively, one flapped rudder, and one rudder with end plates on tips. In the circulating water channel, model test was carried out for measuring lift characteristics of the rudders in open water. And various captive model tests were also carried out for measuring the experimental constants related with helm angle and steering in hull-propeller-rudder system. From the test results, the changes in manoeuvring hydrodynamic derivatives due to adoption of normal and special rudders were predicted. Then course stability performances of a ship with normal and special rudders were evaluated and discussed. As a result, it is clarified that the rudder with concave or convex strips and flapped rudder have no effect on course stability, while the rudder with end plates improves course stability with effect. The result in this study is expected to be used usefully when the course stability is in issue and has to be improved without amendment of hull design at initial design phase or after construction of a ship.

• Smart Media Journal
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• v.9 no.2
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• pp.51-62
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• 2020

Starting with the "Smart Grid National Road Map" in 2010, the Smart Grid 2030 was introduced through the basic plan and implementation plan of the intelligent power grid with the goal of building the world's first national smart grid. In this paper, we intend to build a power domain ontology based on the power business platform based on the upper and lower conceptual models of the "Smart Grid Interoperability Standard Framework and Roadmap", the standard of implementation plan. Ontology is suitable for expressing and utilizing the smart grid conceptual model because it considers hierarchical structure as knowledge defines the properties of entities and relationships between entities, but there is no research related to them. Therefore, in this paper, the upper ontology was defined as a major category for smart grid-related fields, and the lower ontology was defined as detailed systems and functions for the upper ontology to construct the ontology. In addition, scenarios in various situations that could occur in the power system were constructed and significant inference results were derived through inference engines and queries.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.15-24
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• 2001

In order to achieve a desirable tooth movement, it is of great importance to control the M/F ratio and to know the location of the center of resistance. The purpose of this study was to locate the center of resistance and the axis of rotation, and to estimate the stress distribution in the periodontal ligament with experimental model. After preparing a model of an upper canine with a simulated periodontal ligament and alveolar bone, the force and moment were applied. The tooth movement was traced using measuring device with LVDTs(Linear variable differential transformers) that can measure three dimensional tooth movement in real time. The results were as follows. 1. The location of center of resistance by transverse force was $29\%$ of root length measured from alveolar crest to apex regardless of force magnitude. The position of the center of resistance is more coronal than that of two-dimensional model($42\%$). 2. The center of resistance and the axis of rotation coincide when couple moment was applied. 3. As the magnitude of moment increases, tooth tends to extrude irrespective of the direction of the moment. 4. The relationship between location of force and axis of rotation (a x b = $49.6\;mm^2$) was obtained. A tooth movement can be predicted through this formula. 5. The centers of rotation by transverse force were plotted linearly.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.9
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• pp.279-292
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• 2014

Energy aware server cluster aims to reduce power consumption at maximum while keeping QoS(quality of service) as much as energy non-aware server cluster. In the existing methods of energy aware server cluster, they calculate the minimum number of active servers needed to handle current user requests and control server power mode in a fixed time interval to make only the needed servers ON. When loads change rapidly, QoS of the existing methods become degraded because they cannot increase the number of active servers so quickly. To solve this QoS problem, we classify load change situations into five types of rapid growth, growth, normal, decline, and rapid decline, and apply five different thresholds respectively in calculating the number of active servers. Also, we use a flexible scheme to adjust the above classification criterion for multi threshold, considering not only load change but also the remaining capacity of servers to handle user requests. We performed experiments with a cluster of 15 servers. A special benchmarking tool called SPECweb was used to generate load patterns with rapid change. Experimental results showed that QoS of the proposed method is improved up to the level of energy non-aware server cluster and power consumption is reduced up to about 50 percent, depending on the load pattern.

• Korean Security Journal
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• no.16
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• pp.81-99
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• 2008

Despite its legal, systematic and quantitative growth, Korean private security has not been showing satisfactory level of qualitative growth comparing to quantitative growth as it socially shocked with recent occurrence of the events and accidents. People on demand of security are making use of private security service to offset insufficient supply of security power as, especially, the incendiarism at Sungryemun last February brought out security issues for nationally important facilities and cultural assets, and other cases showed that the police would not cope with the appropriate security services under the current security system for protecting the life and property of people. For the supplementation of security power, the private security service is prevalent, but lots of service providers would not overcome its small business scale, except some large-sized security providers. There are some problem occurred as some providers employed staff who would not have the stuff for performing security service and they even committed illegal actions. Some opinions pointed out that it should come up with measures as they socially lose their credit. Therefore, this research suggests the recognition of the importance and the improvement measures of human resources management as follows. Security Service needs: 1. control of criteria for the employment/recruitment of human resources; 2. inducement of qualitative improvement of security service by ensuring excellent quality of human resources; 3. elevation of morale of organizational members with the operation of efficient promotion system; 4. introduction of professional certification system for the inflow of excellent quality of human resources.

• Korean Security Journal
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• no.56
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• pp.145-163
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• 2018

Recently, security behavior of members of organizations has been recognized as a critical part of information security at the corporate level. Leakage of customers' information brings more attention to information security behavior of organizations and the importance of a task force. Research on information breach and information security is actively conducted of personal behavior toward security threats or members of organizations who use security technology. This study aims to identify factors of influence on information security behavior of members of organizations and to empirically find out how these factors affect information security behavior through behavior toward attitude, subjective norm and perceived behavior control. On the basis of the research, this study will present effective and efficient ways to foster information security activities of members of organizations. To this end, the study presented a research model that applied significant variables based on integration of Theory of Planned Behavior (TPB) and Theory of Protection Motivation (TPM). To empirically verify this research model, the study conducted a survey of members of organizations who had security-related work experience at companies. So, it is critical for members of organizations to encourage positive word of mouth (WOM) about information security behavior. Results show that based on the integration of TPM and TPB, perceived vulnerability, perceived severity, perceived efficiency and perceived barriers of information security behavior of members of organizations had significant influences on mediating variables such as behavior toward attitude, subjective norm, perceived behavior control and intention. They also had significant influences on organization information security behavior which is a dependent variable. This study indicates companies should introduce various security solutions so that members of the organizations can prevent and respond to potential internal and external security risks. In addition, they will have to take actions to inspect vulnerability of information system and to meet security requirements such as security patches.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.36-42
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• 2021

When the landfill gas generated at the landfill site is released into the atmosphere, methane gas with a high global warming potential is emitted, which adversely affects climate change. When methane contained in landfill gas is used as fuel for internal combustion engines and burned to generate electricity, it is emitted into the atmosphere in the form of carbon dioxide, which can contribute to lowering the global warming potential. Therefore, in order to use the landfill gas as fuel for power generation using an internal combustion engine, it is important to increase the thermal efficiency of the engine. Thus, it is necessary to use a fuel supply system in which gas is injected using an electronically controlled injector at an intake port for each cylinder rather than a fuel supply technology using the conventional mixer technology. In order to use the electronically controlled gas injection method, it is important to accurately measure the mass flow rate according to the conditions of using landfill gas. For this, a study was conducted to measure the injection amount and calculate them in order for the intake port gas injection of landfill gas.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.27-37
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• 2022

With the recent increase in the spread of ESS (Electric Storage System), the damage to human life and property is also rapidly increasing due to continuous fires caused by ESS. In the manufacture of urethane sandwich panels used in ESS, it is necessary to improve the flame retardant performance. In this study, in order to realize the flame retardant properties of flexible polyurethane foam, the effect of the tissue density of the product due to the change of the isocyanate functional group parameter that changes the physical properties of the product on the fire performance was studied. The product was manufactured by changing the density of the urethane structure, and combustion performance tests, gas toxicity tests, and smoke density tests were performed. As a result, it was confirmed that the total amount of heat released had excellent performance when the isocyanate functional group was high, and had no correlation with the maximum heat release rate. When the value of the isocyanate functional group was 2.7 or more, the collapse of the shape could be prevented. In the gas hazard test, the performance was increased when the isocyanate functional group was relatively high, so a flame retardant for the Char system, which had a dense structure and easy to form a carbonized film, was added. confirmed to be. Therefore, as a result of this study, it is thought that it will be possible to lay the foundation for the development of a flame retardant to replace the cheap urethane sandwich panel used in the past.