• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.420-427
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• 2017

Recently, the depletion of fossil fuels, global warming and environmental pollution have emerged as a worldwide problem, and studies of new renewable energy sources have been progressed. Among the many renewable energy sources, the use of bio fuel has the potential to displace fossil fuels due to low price, easy to handle, and the abundant sources. Pyrolysis oil (PO) derived from waste wood and sawdust is considered an alternative fuel for use in diesel engines. On the other hand, PO is limited to diesel engines because of its low cetane number, high viscosity, high acidity, and low energy density. Therefore, to improve its poor properties, PO was mixed with alcohol fuels, such as ethanol. Early mixing with ethanol has the benefit of improving the storage and handling properties of the PO. Furthermore, a PO-ethanol blended fuel was injected separately, which can be fired through pilot-injected diesel in a dual-injection diesel engine. The experimental results showed that the substitution of diesel with blended fuel increases the amount of HC and CO, but reduces the NOx and PM significantly.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1227-1259
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• 2014

This paper explores agricultural extension systems, extension challenges, research and extension models, governance structures of agricultural extension and advisory services in Sudan. Agricultural extension services in Sudan are provided by a variety of governmental department and corporation. The Technology Transfer and Extension Administration under the Ministry of Agriculture and Irrigation, had been launched during mid 2000's aims at making extension systems farmer driven and farmer accountable by way of new institutional arrangements for technology dissemination in the form of community participation approach at the state level, to make the extension reforms have the active participation of farmers/farmer groups. The main problem facing agricultural extension services in developing countries is poor link between extension organization and research. Both extension administration and Agricultural Research Corporation (ARC) are operating as departments of ministry of Agricultural and irrigation for very long time. There are three recommendations to achieve the effectiveness of the Agricultural Research Corporations (ARC) in reaching farmers. Firstly, extension staff members should be assigned to every ARC station. Secondly, the ARC might increase positions for Agricultural development specialist or Farming System Research (FSR) specialist. Their role would be to reflect the needed of farmer and translate them to the researchable topics. Thirdly, researcher should conduct more research on farmer's fields.

• Journal of Internet Computing and Services
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• v.13 no.6
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• pp.41-53
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• 2012

Open educational resources(OER) enable the spread of mutual information exchange and provide advantages to both their users and institutions, such as reducing costs, improving content quality, and establishing relationships. The recent research on OER was about their connection to formal education, copyright trends, and corporate e-learning. There have been very few studies, however, on the utilization of OER and on the problems related to their practical use. Thus, this study was conducted for the purposes of analyzing the status of OER usage in education-related institutions and of providing suggestions for institution operation based on the analysis results, to promote the use of OER. A survey was conducted among more than 200 institutions in Asia, and the survey results showed that 'images and visual materials' are the most commonly used materials in Asia, and that the factors barring OER usage in the said region are 'lack of awareness', 'lack of skills', 'the absence of a reward system', and poor cooperation in participation. To promote OER usage, each institution should provide training courses about awareness, utilization skills, and copyrights. There is also a need to provide support for the establishment of reward systems and environments for OER usage. Finally, more active participation is required for inter-agency cooperation in OER sharing.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.14 no.1
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• pp.22-25
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• 2018

Lennox-Gastaut syndrome (LGS) is one of the most severe epileptic encephalopathies of childhood onset. It is characterized by multiple types of generalized seizures, slowness of intellectual growth, and specific electroencephalogram pattern. It is one of the most difficult epilepsy syndromes to treat and is frequently resistant to treatment. In this case report, we report a case of dental treatment under general anesthesia in a child with LGS. A 4-year-6-month old boy with LGS visited Seoul National University Dental Hospital for dental treatment. Dental treatment was planned under general anesthesia because of his medical condition. Treatment was successfully done without any postoperative complications. If a LGS patient requires dental treatment, a treatment plan should be established to take into account the degree of seizure, the medication being used, and the cooperation of the patient. If the degree of seizure is severe and the patient's cooperation is poor, dental treatment under general anesthesia would be advantageous.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.367-375
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• 2008

Anchorage plays an important role in orthodontic treatment. Skeletal anchorage like the miniscrew is considered a more effective method in anchorage control than conventional anchorage which needs much patient's cooperation. The miniscrew offers many advantages. 1) It is easy to insert and to remove. 2) It can endure the force needed for moving teeth. 3) It can be immediately loaded and 4) Patient cooperation is not needed. 5) It is economic compared to other skeletal anchorage systems. In comparison to adult's bones, children's bones have comparatively poor bone quality and quantity. Therefore, it is hard to obtain primary stability in younger patients. However, if the miniscrew can be retained successfully, it will be effective in many orthodontic treatments. In these cases, we used the miniscrew in correcting of diastema, in aligning dental midline, and in rendering a forced eruption of impacted tooth in mixed dentition patient. We obtained satisfactory results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.573-586
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• 2016

In construction jobs, a combination of various kinds of machinery is used to perform earthworks at a large-scale site. Individual equipments essentially cooperate with each other on task such as excavation, load, transfer and compaction. While other area have studied cooperation system, related study in domestic construction is in poor condition. In this study, construction equipment fleet management system is developed for solving this problem and find way to improving efficiency in earthworks site. The entire concept of the fleet management system, including its components and process, has been systematically outlined in this paper. An operational methodology has also been suggested, where a number of machines, such as the excavators, trucks and compactors, are chosen and further grouped into a cluster. A case study verify fleet management system's effectiveness on performing task package by comparing existing work method with methodology in this study. Fleet management system in this study is expected to curtail fuel consumption by the reduction of working time and moving distance. Furthermore, it can be anticipated to declining carbon emission effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.581-586
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• 2018

Cast iron manhole lids cause environmental pollution during the manufacturing process, and the work environment is very poor. In addition, if the height of the manhole cover does not match the height of the road surface, it causes considerable inconvenience and safety problems. This study proposes a height - adjustable steel manhole cover that can replace cast iron manhole covers and easily match the road surface with the upper surface of the manhole cover. Structural analysis was performed to grasp the design variable of the structure of the manhole cover, satisfying the required quality performance. To fabricate a manhole cover that satisfies the required load capacity, the optimal design for the U-shaped reinforcement structure was made. The cylindrical shape of the height adjustment part and the low frame were formed by bending the steel sheet into a circular shape and then welding. Reinforcing bars were also made by bending a steel plate. The height adjustment groove was machined by a CNC milling machine. Four prototypes were fabricated and a load bearing test was carried out, and new manhole cover was made reflecting results of the test. In the load bearing test, there was no breakage of the welded part, and deformation occurred mainly at the contact area between the groove and gusset plate. Deformation of 1 to 2.7mm occurred due to a load of 450kN. On the other hand, after removing the load, there was almost no residual deformation, and the load bearing evaluation was judged to be satisfactory because the manhole cover could be disassembled and reassembled.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.323-335
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• 2017

Recently, Korea is facing a trend of a fast-paced change towards a multi-cultural society, accompanied by the consequential increase in population and many changes in the peripheral environment. Particularly, the influx of multi-cultural families in Ansan City is increasing every year, but their housing environment remains in poor conditions. Actually, the research on housing policy for multi-cultural families and their housing satisfaction is restrictive. It is therefore necessary to research on how to overcome this problem, and what realistic policy alternatives are required. The purpose of this study is to present some policy alternatives to improve the housing satisfaction of the Korean-Chinese residing in Ansan City. To this end, this study conducted empirical analysis with a focus on Korea-Chinese multi-cultural families living in Ansan City through a questionnaire. As the analysis method, this study conducted frequency analysis, descriptive statistical analysis, cross analysis, and regression analysis, and used the statistical package-SPSS 20.0 as an analysis tool. As a result of the research, first, it was found that their awareness of the government housing policy is insufficient; second, they had a lot more hardships in housing due to the problem of the rising house prices caused by urban development & regeneration; third, in terms of housing tenure type, there was a higher proportion of a lease on a deposit basis and monthly rent than owner-occupied housing. Hence, this study drew the conclusion that the Korean-Chinese multi-cultural family's housing environment needs to be improved and policy support is required for Korean-Chinese. In addition, this study gives great significance in providing these research results as basic materials which make it possible to inquire into mutually reciprocal practice plan and strategic alternatives for a multi-cultural families from now on.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.479-488
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• 2016

This study developed an instrument to assess the effects of the bullying of nurses in the workplace and evaluated the developed instrument. A literature review and a field study were conducted to identify the concepts related to the bullying of nurses in the workplace. These attributes served as building blocks to produce a 28-item WPBN-CI. The content validity was used to determine the content and face validities, and the number of instrument items was reduced to 14. The final WPBN-CI instrument was evaluated using the SPSS 18.0 program with the data collected from October 21-28, 2013 from 458 nurses from general hospitals in the metropolitan area. The WPBN-CI consisted of 13 items covering three distinct factors (physical and psychological withdrawal, poor quality of patient care, and increasing distrust), with a total variance of 62.9%. The convergent and determinant validities for the WPBN-CI were 100% and 89.7%, respectively. The known-groups validity was proven through the mean difference in the level of depression. The satisfied criterion validity for the WPBN-CI was more than 0.70. The reliability of the WPBN-CI was demonstrated by its Cronbach's ${\alpha}$ of 0.90. The WPBN-CI will identify in advance the results due to the bullying of nurses in the workplace and will help to find solutions to the problem and ensure program effectiveness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.706-713
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• 2016

In this study, the welding characteristics of friction stir welding were investigated in accordance with the tool plunge position and cooling to the base materials for the joining of dissimilar materials (A6005-AZ61). Other different welding conditions, such as the tool rotation speed and welding speed, were fixed to 500rpm-30mm/min, respectively, and welding was then carried out by placing the Mg alloy (AZ61) on the advancing side and Al alloy(A6005) on the retreating side. Welding was conducted under six different conditions. To investigate the welding characteristic, tensile test and microstructure observations using an optical microscope were carried out. As the tensile test result, the maximum strength appeared under the condition in which the tool is moved 1 mm to the Mg alloy direction and cooling to the base materials. Under the same welding conditions, the strength with cooling was approximately two times higher than that without cooling. The tool was located in each direction of 1.7 mm from the weld line. Therefore, in the excessive off-set of tool position, the welding integrity was in an extremely poor condition due to the lack of stirring. This study was confirmed by the A6005-AZ61 dissimilar friction stir welding the welding speed and the tool rotation speed. In addition, the temperature control and tool plunge position are important welding parameters.