• Journal of the Institute of Electronics and Information Engineers
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• 제53권5호
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• pp.19-24
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• 2016

In Long Term Evolution-Advanced (LTE-A), small cell enhancement(SCE) has been developed as a cost-effective way of supporting exponentially increasing demand of wireless data services and satisfying the user quality of service(QoS). However, due to the dense and irregular distribution of a large number of small cells, the offloading scheme should be applied in the small cell network. In this paper, we propose an user offloading scheme for SCE in LTE-Advanced system. We divide the small cells into different clusters according to the reference signal received power(RSRP) from user equipment(UE). Within a cluster, We apply the user offloading scheme with the consideration of the number of users and interference conditions. Simulation results show that proposed scheme can improve the throughput, and spectral efficiency of small cell users. Eventually, proposed scheme can improve overall cell performance.

• Journal of the Institute of Electronics and Information Engineers
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• 제53권5호
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• pp.13-18
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• 2016

In Long Term Evolution-Advanced (LTE-A), small cell enhancement(SCE) has been developed as a cost-effective way of supporting exponentially increasing demand of wireless data services and satisfying the user quality of service(QoS). However, there are many problems such as the transmission rate and transmission quality degradation due to the dense and irregular distribution of a large number of small cells. In this paper, we propose a clustering based interference management scheme in dense small cell network. We divide the small cells into different clusters according to the reference signal received power(RSRP) from user equipment(UE). Within a cluster, an almost blank subframe(ABS) is implemented to mitigate interference between the small cells. In addition, we apply the power control to reduce the interference between the clusters. Simulation results show that proposed scheme can improve Signal to Interference plus Noise Ratio(SINR), throughput, and spectral efficiency of small cell users. Eventually, proposed scheme can improve overall cell performance.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제49권1호
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• pp.1-10
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• 2012

Mobility and quality of service (QoS) are becoming the more important issues in wireless communications. The traditional Internet service is expanding into new access media and applications. Since wireless communication services are accompanied by frequent handovers at remote sites, scalable and fast handover has become a prerequisite for ubiquitous communication. In this paper, the differentiated service (Diffserv) model is deployed in heterogeneous proxy mobile IPv6 (PMIPv6) networks to satisfy the QoS guaranteed service and fast handover requirements. The operational procedures for QoS guaranteed global roaming are presented. In addition, QoS management and handover cost evaluation schemes based on a mobile host's movement scope are proposed. This paper analyzes the reduction in handover delay in a network-based localized mobility management framework. We propose and analyze a PMIPv6 optimized with a global mobile access gateway (G-MAG), which is a network-based entity, to further improve the handover performance in terms of handover delay while maintaining minimal signaling overhead in the air interface among converged heterogeneous wireless networks. The handover signaling procedures with host-based MIPv6 are compared with network-based proxy MIPv6 (PMIPv6) and fast PMIPv6 assisted by G-MAG to show how much handover delay reduction can be achieved. Analytical results show that the handover delay is significantly reduced.

• Journal of the korean academy of Pediatric Dentistry
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• 제40권4호
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• pp.335-341
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• 2013

Impacted maxillary canines are the most frequently impacted teeth after the third molars. The exact etiology of impacted maxillary canines is unknown, but several complications may result from impacted maxillary canines. An early detection of ectopically erupting teeth can lead to performing interceptive treatment such as early extraction of primary canine and provide the best long-term results. In the absence of prevention, clinicians should consider orthodontic treatment followed by surgical exposure of the canine to bring it into occlusion. However, in cases when the finding ectopically erupting teeth and severe root resorption of adjacent teeth are found late, malposed canine can replace the injured teeth. In these presented cases, early diagnosis and treatment of ectopic eruption and root resorption were not performed. The maxillary incisor replacement with ectopically erupting canine can be the alternative treatment of choice with successful results. The reconstructed canine is planned to be checked periodically for the condition of composite resin restoration. Orthodontic treatment and dental implant are planned. This report shows that when early diagnosis was not done, maxillary incisor replacement with ectopically erupting canine could prevent uncertain prognosis of the adjacent teeth with root resorption and provide esthetic satisfactory with time saved and cost reduced.

• Journal of the Korea Organic Resources Recycling Association
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• 제8권4호
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• pp.129-137
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• 2000

In this study, biological treatment process of MWWT(Municipal wet-waste Treatment) has been developed through a moduling of the containerized closed ATAD(Auto thermal aerobic digestion) system & closed vertical dynamic acerator, which were used for food waste and cattle manure, respectively. Though biological process has several advantages such as low concentrations of heavy metals and salts, proper and stable C/N ratio and constant reaction rate against the process treating two wastes separately, it has a obstacles of salt concentration and much usage of bulking agent such as wood chip. After rapid oxidation in the boxed tower reactor for 5 days, the content of sewage sludge would be reduced 65% on around, might be mixed with the food waste that had been treated in the static closed reactor during 6 days and put in the secondary static reactor for curing. During composting process, the odor contained in the gas generated from the reactor was removed by passing it through a biofilter as well as the leachate was treated in the wastewater treatment facility. Consequently, it seemed to be possible to compost sewage sludge at mild and stable operating condition and at low cost through the biological ATAD process resulting in the production of organic compost satisfying the specifications regulated by itself.

• Journal of the Korea Organic Resources Recycling Association
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• 제8권4호
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• pp.67-77
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• 2000

For successful privatization of environmental facility, a sound environmental policy is required to satisfy social motivation and economic. The primary purpose of environmental facility is not profit, but to supply a good quality service, an efficient management tool is needed to run the facility. In foreign countries, the privatization policy was originally based on the principle of complete competition achieving economic effiency. There were efficient cooperation and division of labor between civillian and public sector. First of all, the local government had independant budget. But, we found that the environmental facility have two important problems, the first is low effiency of operation and the second is comsumed to government finances as a homemade rate 50% in the technic application For a successful privatization of the environmental facility, The law of private capital introduction should be amended to promote fund raising. There are some other strategies ; overcoming of Nimbyism, research development of the privatization, field trip to the successful foreign environmental facilities. To support an efficient privatization policy, the environmental budget should be managed by cost-benefit analysis.

• Journal of the Korean Institute of Landscape Architecture
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• 제41권6호
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• pp.29-42
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• 2013

The purpose of this study was to derive selection attribute of fishing experience villages, and to analyze the importance and performance on targeting experts and experienced tourists. Consequently, it could suggest implications for the guideline and the evaluation criteria of making fishing experience villages for the revitalization of eco experience tourism. Therefore, in this study, literature investigation and IPA analysis were used by Microsoft Office Excel 2010, SPSS 20.0. As a result, the 'variety of local foods and specialties' was the most urgent attribute to require intensive management strategy. And it is recommended to improvement about 'attributes related residents' because it were insensitived on the recognition by users. Satisfaction of 'appropriateness of coast' was the lowest, but the efficiency was quite high. Finally, not only 'the area of control' but also 'the area of influence' should be reviewed as an important aspects on developing the fishing experience village. The significance of this study is to derive selection attributes of making fishing experience villages for revitalization of eco experience tourism, and to suggest strategy directions based on IPA analysis result by experts and experienced tourists. But in this study, the site was limited to Gyeonggi-do, so it is recommended to expand further.

• Journal of Internet of Things and Convergence
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• 제6권3호
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• pp.21-30
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• 2020

The purpose of this paper is to verify the differences of the effect of the support between the number of employment of those who have experienced employment and the unemployment period of those who have not experienced employment for the participants of the Jeollanam-do Youth Job Search Allowance Support Project. In addition, this study attempted to find out the ways to develop the system using the Internet of Things by figure out how to use the allowance, the field of help, the average investment time per day, the average monthly expenditure, the difficulties of job search activities, and the differences in the youth job search activities for the required programs. In this study, 602 people who participated in the Jeollanam-do Youth Job Search Allowance Support Project from February 19 to March 9, 2020 are surveyed. The collected data was processed using the SPSS 21.0 program. The research results are as follows. First, there was a difference in satisfaction according to the number of jobs employed. Second, there was a difference in the effectiveness according to the number of employment. Third, there was a difference in satisfaction according to the period of unemployment. Fourth, there was a difference in effectiveness according to the period of unemployment. In order to enhance the effectiveness of the youth job search allowance support project, the Edutech industry and technology that can share various information using the Internet of Things environment in the untact era must be improved together.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2006년도 정기학술발표대회 논문집
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• pp.98-102
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• 2006

This study was conducted to derive a priority of investment in educational facilities by collecting and analyzing investment records from elementary, middle, and high schools in Chung Nam area. In addition, the AHP survey and analysis were performed in order to draw the priority item in the educational facility improvement. Students, parents, teachers and a educational facility managers from those schools provided their opinions and data for the AHP study. As a result of the study, the actual investment-cost and a lack of educational facilities were found. A priority item based on the above study was derived which can be used to increase user's satisfaction in the educational facilities. The result of this study can be used as a basis to improve the environment of the educational facilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권12호
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• pp.135-139
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• 2017

The main reason for heat accidents occurring at the after stern tube bearing (STB) is excessive local pressure caused by the deflection of the propulsion shaft due to propeller loads. The probability of a heat accident is increased by the low flexibility of the shaft system in very large crude oil carriers (VLCCs) as the engine power and shaft diameter increase and the distance decreases between the forward and after STBs. This study proposed shaft system with only an after STB and no forward STB for a flexibility acquisition method for a VLCC shaft system under hull deformation. A Hertzian contact condition was applied, which assumes a half-elliptical pressure distribution along the contact width for the calculation of the local squeeze pressure. The propeller loads, heat effect, and hull deflection under engine operating conditions are also considered. The results show that the required design criteria were satisfied by building a partial slope at the white metal, which is the material at the axial contact side in the after STB. This system could reduce building cost by simplification of the shaft system.