• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.495-501
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• 2016

Mineral oil has been widely used as an insulating oil for electrical transformers for a long time, but the necessity of employing new insulation oil such as vegetable oil has been increased due to urgent needs for the biodegradability when it leaks and also for the thermal stability at a higher operation temperature. Although specific periods are required between the production and consumption, there are still short of the data to prove the insulation oils' storage stability depending upon various circumstances and their resources. Thus, this paper demonstrates the insulation oils' oxidation characteristics of both mineral and vegetable oils when each was exposed to different environments for 12 weeks. From this test, some properties including total acid number, water content and dielectric breakdown were changed under specific conditions and resources. Vegetable oils showed higher hydrophilicity and water saturation than those of mineral oils due to their molecular compositions. Under sunlight exposure condition, all insulation oils oxidized and changed their properties when exposing to the direct light, regardless of the resource used.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.208-222
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• 2023

With the recent revision of 「Act on Promotion of the Transportation Convenience of Mobility Disadvantaged Persons」 and the Enforcement Regulations of the Act, bus business operators must introduce low-floor buses when scrapping buses. On the other hand, in the case of routes where low-floor buses cannot be operated, bus business operators can be exempted from introducing low-floor buses with the approval of their transportation administrative agency according to Article 4-2 of 「Enforcement Regulation of the Act on Promotion of the Transportation Convenience of Mobility Disadvantaged Persons」. According to the data from the Korea Bus Transportation Associations Federation, approximately 5.9% of all city bus routes were surveyed as the exceptions to introducing low-floor buses. Nevertheless the proportion is expected to increase because some regions with difficulties introducing low-floor buses are not included when calculating the proportion. By confirming the process of approving exceptions for introducing low-floor buses through local governments, there was no specific examination method or standard for approval of exceptions. Hence, there is the problem that some routes are approved as exceptions to introducing low-floor buses, even though low-floor buses can be operated on those routes. Therefore, this study aims to develop a manual that can objectively diagnose the overall operation environment of low-floor buses, such as road geometry and road facilities. Future research plans to apply it to more cases and improve it for more precise application in various contexts.

• Asian Journal of Business Environment
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• v.13 no.2
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• pp.1-7
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• 2023

Purpose: The purpose of the study is to explore the factors which influence the night-time economic development in Hanoi, Vietnam. The results can help policymakers achieve a scientific basis to plan the development of night-time economy in Hanoi. Research design, data and methodology: The research model is developed from literature review with 7 independent variables, including natural conditions and resources, infrastructure, safety, environmental issues, promotion and international integration, development of sharing economy, and institution and policy. This model is then adjusted by exploratory factors analysis to have 4 new variables: Institution and environment, Infrastructure and safety, Promotion and sharing, and Nature and resources. The model is regressed based on the data of 463 observations of night-time economy in Hanoi, Vietnam. Results: Consistent with the current literature addressing night-time economy, the results show positive impacts of all of the independent variables studied. Conclusions: It is recommended for the local authorities to strengthen advertising and promoting investment for NTE development in Hanoi city and also enhance the role of state management in NTE activities by raising awareness of the state management apparatus towards a more open-minded multi-dimensional view of the NTE, developing the NTE to overcome the barrier of thinking "if it cannot be managed, it is forbidden" in state management agencies, and defining responsibilities and authority among state management agencies in the management of NTE activities and strengthening decentralization and decentralization of powers for localities in the management and development of NTE.

• Journal of the Korean Society of Safety
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• v.27 no.2
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• pp.111-116
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• 2012

This study deals with the traffic accidents of circular intersections in Korea. The purposes are to comparatively analyze the characteristics by operational type, and to develop the models using the data of 82 intersections. In pursuing the above, this study gives particular emphasis to modeling such the accidents as the roundabout and rotary in urban area. The main results analyzed are as follows. First, the null hypotheses that the number of accidents are the same in both the urban and rural intersections, and roundabout and rotary in urban area, were analyzed to be rejected. Second, 3 accident models were developed, which were all statistically significant. The independent variables used in the above models are the ADT, number of approach lane, bus stop, parking facilities, and others. This study could be expected to give some implications to the traffic safety policy decision-making.

• Convergence Security Journal
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• v.4 no.3
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• pp.83-90
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• 2004

Preventive measures and control over cyber terrorism in Korea is a complex problem. Today laws should meet requirements made by modern technologies development, Law enforcement, special services and judicial system cooperation, their efforts coordination and their material security are priority directions, None of the country is able to prevent cyber terror independently and international cooperation in this field is vital. Taking the above into consideration, we propose and inisit that National Intelligence Service(NIS) should share cyber terror data with Police Agency and have top police authority over the cyber terror.

• Journal of Agricultural Extension & Community Development
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• v.6 no.1
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• pp.15-24
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• 1999

There have always been dilemmas between development and environmental conservation throughout the world. Gradually environmental contamination threatens sustainable development and conservation. we try to study on the sustainable development with environmental conservation. One of the instruments to get this goal is Environmental Impact Statement. Environmental Impact Statement has now become a standard tool of decision making in Environmentally Sound and Sustainable Development. The objectives of this study is to explore and suggest some suggestions for improvements of EIA. 1. Identify all criteria and standards that apply to physical and social environmental components and dynamics. 2. Giving attention to the purpose of the criterion and standard, with respect to resource use and quality. 3. Demonstrate the relevance legal, technical, and scientific authority by early planning through construction, operation and maintenance phases. 4. Implement rationales and protocols for the documentation of standard analytical methods, location of sampling points and statistical analysis of data. 5. Establish precise protocols by predictions of environmental impact relevant for established criteria and standards. Reviewing these protocols with relevant legal authorities prior to their implementation is important.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.3
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• pp.177-184
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• 2018

In case that limited resources can be mobilized, non-structural countermeasures such as 'monitoring using Information and Communication Technology might be one of solutions to mitigate disaster risks. Having established the monitoring system, operational and maintenance costs to maximize the effectiveness might trouble the authority concerned or duty attendant who is in charge. In this respect, "Guerrilla Sensor" would be very cost effective because of the inherent mobility characteristic. The sensor device with the IRIS camera and GPS (Global Positioning System) equipped, is basically battery-operated and communicates with WCDMA (Wideband Code Division Multiple Access). It has a strong advantage of capabilities for 'Disaster Response' with immediate and prompt action on the spot, making the best use of IoT (Internet of Things), especially with the mobile web. This paper will explain how the sensor system works in real-time GIS (Geographic Information System) pinpointing the exact location of the abnormal movement/ground displacement and notifying the registered users via SMS (Short Message Service). Real time monitoring with early warning and evaluation of current situations with LBS (Location Based Service), live image and data information can help to reduce the disaster impact. Installation of Guerrilla sensor for a real site application at Gimcheon, South Korea is also reported.

• Journal of Korean Elementary Science Education
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• v.29 no.4
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• pp.414-426
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• 2010

For this study, inquiry-based learning program was developed for promoting elementary students' scientific justification activities based on their uses of scientific evidences. The program was applied to the 5th grade science class to examine the types of evidences and major features of scientific justification activities. Analysis of the data showed that the evidences used by students were classified into knowledge-based evidence, experience-based evidence and authority-based evidence. As for students' justification features, this study reports three major cases: a case evolving evidence and justification to become more valid and logical, as inquiry activities progressed, other case maintaining less valid and illogical evidence and justification, and final case revealing passive and reluctant participation in the inquiry activities. Overall, students' participation in scientific justification process became more valid and relevant, while there were some students who were unable to make the relevant relations between evidences and claims they made. The educational implications were discussed to consider more effective ways to improve the scientific classroom environment through social knowledge construction.

• Journal of the Korean Society of Safety
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• v.29 no.2
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• pp.68-75
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• 2014

The study examined the relationship between six broad personality traits(i.e., HEXACO; Honesty-humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, Openness to experience), safety job performance, and traffic accidents of Korean occupational bus drivers. Based on the job performance model, we included safety participation as well as safety compliance as safety job performance. Analyses on the data from a total of 492 bus drivers showed that all HEXACO personality traits except Honesty-humility, were valid predictors for both safety compliance and safety participation. Honesty-humility was only related to safety compliance. Among the six personality traits, high conscientiousness and low emotionality were best predictors of safety job performance. As for traffic accidents, conscientiousness was a sole significant predictor. Furthermore, the mediation analysis showed that the effect of conscientiousness on traffic accidents was completely explained by safety compliance and safety participation. The implications of the current findings for practice and future research as well as the limitations of the current study were discussed.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.353-361
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• 2012

All current shipyards are using the customized CAD/CAM programs in order to improve the design quality and increase the design efficiency. Even though the data structures for ship design and construction are almost completed, the implementation related to the ship design processes are still in progress so that it has been the main causes of the bottleneck and delay during the middle of design process. In this study, we thought that the hole-plan system would be a good example which is remained to be improved. The people of outfitting division who don't have direct authority to edit the structural panels, should request the hull design division to install the holes for the outfitting equipment. For acceptance, they should calculate the hole position, determine the hole type, and find the intersected contour of panel. After consideration of the hull people, the requested holes are manually installed on the hull structure. As the above, many processes are needed such as communication and discussion between the divisions, drawings for hole-plan, and the consideration for the structural or production compatibility. However this iterative process takes a lot of working time and requires mental pressure to the related people and cross-division conflict. This paper will handle the hole-plan system in detail to automate the series of process and minimize the human efforts and time-consumption.