• Journal of the Korean Society of Industry Convergence
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• v.9 no.1
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• pp.61-66
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• 2006

In perspective of saving natural resource and energy, today's automobiles are in process of regenerating by smaller and lighter. In order to achieve the sufficiency on the consumption of the fuel, new mechanism and new assembly are required. Therefore the expectations on the new materials are very high. Especially, AI materials are widely used to reduce the weight. AI that is used in automobiles is mostly casting material, and according to the innovation of technique is in rapid development. AI Die casting is an important field as today's trend of lightweight on automobiles. One of the parts in steering system, Valve Housing plays a role of reduce the operating effort of drivers. Unfortunately, the Valve Housing which is widely reliable to the most automobiles are not developed at this moment in our automobile industry. Therefore, they are produced by casting method which cost three times or even more expensive in production. If Valve Housing, which is a part of steering system is produced by Gravity Casting, the space that manufacturing equipment will be increased, and more time and workers would be brought into service. For such reason, Die Casting would replace Gravity Casting in order to minimize cost of time, manpower, and working space.

• Journal of Korean Library and Information Science Society
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• v.29
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• pp.171-212
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• 1998

In this study, the concept, developments and the present situations of an electronic document delivery services, projects and systems are examined. Also the implications of an electronic document delivery services in the library and the future of the services are studied. Some conclusions and a few suggestions derived from the study are as follows : (1) An electronic document delivery services, one of the most innovative methods for delivering the needed materials to a researcher is now being incorporated into an important part of today's information industries. (2) The technological developments have made it possible to deliver nearly all the document formats electronically, and can make the shortest turnaround time to be 30minutes. The technology has also made it possible to develop user-friendly document delivery services by providing the various methods of requesting of, delivering of and charging for the materials. (3) Different types of institutions have made researches, tests, developments and implementation of an electronic document delivery techniques with different features. (4) The issues of copyrights and standards involved in an electronic document delivery still remain as the problems to be solved. (5) The increase and development of patron-initiated document delivery services have and will have some impacts on the library services with the possibility to pass by the librarians intermediation, but to deliver the materials directly to the end-users. (6) The library could take the outside electronic document delivery services as an opportunity. Accordingly, in order to incorporate this services in the interlibrary loan, collection development and other library services, the library should establish appropriate policies, guidelines and management strategies related to the operations. (7) In order to maximize the use of the electronic document delivery services, the library should provide an appropriate education for the librarian and users to have knowledge and skills on the changing techniques of the electronic document delivery and on the various features as well as changing mechanisms by each system and service.

• Journal of Internet Computing and Services
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• v.18 no.5
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• pp.123-131
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• 2017

With the rapid growth of mobile services, the various charging methods for mobile data have emerged in the mobile service market. Among them, network operators have begun to provide the zero-rating without any extra charge for the data that use the specific mobile application & services. Zero-rating, the free mobile data services by the network operators provoked many platform operators to confront business opportunity and risk. Though the platform operators are in urgent need of the strategy planning that considers business environments, any research endeavors explaining zero-rating and platform does not exist. Moreover, the analyses of potential effects of zero-rating on the business acts of platform operators has not been performed. Therefore, the study aims to identify the potential business opportunity and risk to prepare the various strategic countermeasure in platform operators' shoes. The study might enable the researchers to properly understand zero-rating and platform, and be utilized as a reference in planning the business strategy of the platform operators.

• Journal of the Korean Home Economics Association
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• v.41 no.1
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• pp.187-211
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• 2003

This study deals with activities in internet, including activities on consumer counseling, exchange of consumer information, and anti-sites. Among consumers having utilized those three types of internet sites, this study examines whether their satisfactions on them differ depending on their socio-demographic characteristics and types of activities and also explores which factors critically influence consumer satisfactions. According to the results of this study, consumers' satisfactions were higher when consumers evaluated counselors were objective, rapid, and reliable. Thus, Counselors must be more efficiently classify counseling contents, systematically manage, rapid, active and concrete answers for consumers applying for counseling. Second, in the case of consumer information site, the consumer satisfaction turns out to be positively related with exchange of consumer information, rapid provision of information, and reliability. Connection of relevant specialized information, encouragement of active information exchange among consumers, and objectivity and specialty in consumer information site are necessary to increase the quality of internet consumer information cite. Third, in the case of anti site, consumer satisfaction is higher in cases of consumer being joined in anti-site and in cases of objective and reliable sites. In order to facilitate the utilization of anti-sites, those solutions include systematic classification and management of writings listed in the site, active management of the site managers, reducing criticisms on the writings listed and objectivity of information provided, and active searches for solutions. Finally, in order to preserve consumer sovereignty, policy suggestions include improvements of service qualities provided in internet sites, active advertisement, improvement of site management through charging some fees for users, enhancing specialties.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.228-238
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• 2010

There is an increasing interest in research to help overcome the energy crisis that has been focused on energy storage applications in various parts of power systems. Energy storage systems are good at enhancing the reliability or improving the efficiency of a power system by creating a time gap between the generation and the consumption of power. As a contribution to the various applications of storage devices, this paper describes a novel algorithm that determines the power and storage capacity of selected energy storage devices in order to improve upon railroad system efficiency. The algorithm is also demonstrated by means of simulation studies for the Korean railroad lines now in service. A part of this novel algorithm includes the DC railroad powerflow algorithm that considers the mobility of railroad vehicles, which is necessary because the electric railroad system has a distinct distribution system where the location and power of vehicles are not fixed values. In order to derive a more accurate powerflow result, this algorithm has been designed to consider the rail voltage as well as the feeder voltage for calculating the vehicle voltage. By applying the resultant control scheme, the charging or discharging within a specific voltage boundary, energy savings and a substation voltage stabilization using storage devices are achieved at the same time.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.121-127
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• 2020

Since the Fukushima nuclear accident in 2011, the public were concerned about the safety of Nuclear Power Plants (NPPs) in extreme natural disaster situations, such as earthquakes, flooding, heavy rain and tsunami, have been increasing around the world. Accordingly, the Stress Test was conducted in Europe, Japan, Russia, and other countries by reassessing the safety and response capabilities of NPPs in extreme natural disaster situations that exceed the design basis. The extreme natural disaster can put the NPPs in beyond-design-basis conditions such as the loss of the power system and the ultimate heat sink. The behaviors and capabilities of NPPs with losing their essential safety functions should be measured to find and supplement weak areas in hardware, procedures and coping strategies. The Loss of Ultimate Heat Sink (LUHS) accident assumes impairment of the essential service water system accompanying the failure of the component cooling water system. In such conditions, residual heat removal and cooling of safety-relevant components are not possible for a long period of time. It is therefore very important to establish coping strategies considering all available equipment to mitigate the consequence of the LUHS accident and keep the NPPs safe. In this study, thermal hydraulic behavior of the LUHS event was analyzed using RELAP5/Mod3.3 code. We also performed the sensitivity analysis to identify the effects of the operator recovery actions and operation strategy for charging pumps on the results of the LUHS accident.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.288-294
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• 2018

The entertainment system of the aircraft has changed its paradigm in the form of using passenger electronic devices instead of using a fixed monitor. This has simplified the on-board equipment while the risk of safety has increased with the electric charging of portable electronic devices. Unlike personal portable electronic devices that do not have a transmission function, the use of Wi-Fi enabled electronic devices(T-PED) is allowed and the battery is required to be charged in the cabin. In this study, we used the NASA Aviation Safety Reporting System to investigate the effects of changes in wireless environment and entertainment service. Based on this, we analyzed the risks of personal electronic devices by sharing event occurrence cases caused by in-flight electronic equipment or passenger portable electronic devices(especially smart phones) from the viewpoint of aircraft safety management. This analysis includes identification of potential hazards and risk assessment, and finally the strategies for risk mitigation for safe use of portable electronic devices are suggested.

• Journal of Korea Game Society
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• v.18 no.6
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• pp.121-130
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• 2018

Game users purchase contents in order to enjoy games, which is the case as for minors. The most frequently used payment method for minors' purchasing game contents is many kinds of gift certificates. Other payment methods include adding the payment to their cellular phone bills and charging it to their parents' credit cards. Although such payment methods are easily used due to convenience, consequent disputes are also continuously increasing. Both users and game service providers suffer damage due to the disputes related to game payments by minors and, in some cases, such problem also becomes a social issue. The purpose of this study is to present data for the standardization of refund policy (system) for payments made by minors by investigating and analyzing the laws and institutions related to game payments by minors and examining relevant dispute cases, in order to prevent and solve such disputes efficiently.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.537-544
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• 2022

As the penetration of electric vehicles and development of new models, user experience factors are getting more important in designing connectivity systems for car infotainment services. The primary object of this study is to identify commonalities and differences by comparing user experience factors in the Korean and US electric vehicle markets. This study derived connectivity keywords by text mining the vehicle introduction on the market in each country, and performed centrality, cluster analysis and visualization mapping using the semantic network analysis. As a result, the Korean new electric vehicle connectivity service mainly focused on driving functions such as driving, parking assistance, and charging, while US focused on device connection, convenience function control, app use, entertainment viewing. Based on the analysis, this study presented the practical implications in marketing, system design, and HMI design.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.23-29
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• 2021

The purpose of this study is to reduce the probability of occurrence of electric fires as a preemptive preventive measure, and to strengthen the capability of preventing electric fires by strengthening the cooperative function between electric fire-related departments and establishing a cooperative system. In this study, the general aspects of electric fires were identified by reviewing the literature such as ignition mechanisms of electric fires. And the major electrical fires that occurred in the last 10 years were classified into ignition factors (short circuit, overload/overcurrent, and earth leakage/ground fault) and ignition sources (wiring/wiring appliances, electrical equipment/household appliances). And the 4M technique was used to analyze the potential causes of ignition at the fire site and to suggest preventive measures. In the case In this study, out of 48 electrical fires in the past 10 years, 16 short-circuit fires, 3 overload/overcurrent fires, 3 short-circuit and earth fault fires, 16 fires in wiring/wiring appliances, and 10 fires in electrical equipment/home appliances classified as cases. And prevention measures were presented in terms of human, machine, media, and management by using the 4M technique. For the preemptive prevention of electric fires, strengthening the compulsory electrical safety inspection and making it mandatory to report when new or expanding electric facilities, charging a fee for electric safety inspection for detached houses and granting benefits subject to inspection completion, improvement of the electric safety voluntary inspection table and safety indications; It was suggested as a policy to organize and operate electrical safety inspection personnel in a two-person team (mixed), establish a close work cooperation system with related organizations, and strengthen electrical safety education and publicity.