• Korean Journal of Social Welfare
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• v.54
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• pp.99-121
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• 2003

The purpose of this study is to explore the process that youths get involved in delinquent behavior after runaway. The experiences of runaway youths are studied interpretively, so that interactive features between situations and the youths are revealed. In this way, it is expected that directions in social services to prevent and intervene with delinquent behaviors of runaway youths can be suggested. Eleven youths who have experienced running-away participated in the in-depth interviews. Their narratives are interpreted through the procedures of interpretive interactionism by Denzin(1989). Five phases of the delinquency process have been discovered: Using personal resources, getting help from new relationships, exploring alternatives to survive, learning delinquent way of living, and living independently through delinquency. Interpreted contextually, it has been founded that delinquency is a behavior to survive and a developmental process on the street, taking place in a situation of blocked communication, nevertheless within people's networks. Thus, it is suggested that the problem of runaways are not to be treated narrowly as responsibilities of the youths themselves or their families, but to be approached from the viewpoint of providing social service systems that work as a safety network and offer alternatives for the youths to survive, to resolve their troubles, and to keep healthy lives.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.9-18
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• 2009

Recently, due to the advanced technologies of mobile devices and wireless communication, there are many studies on telematics and LBS(location-based service) applications. because moving objects usually move on spatial networks, their locations are updated frequently, leading to the degradation of retrieval performance. To manage the frequent updates of moving objects' locations in an efficient way, a new distributed grid scheme, called DS-GRID (distributed S-GRID), and k-NN(k-nearest neighbor) query processing algorithm was proposed[1]. However, the result of k-NN query processing technique may be invalidated as the location of query and moving objects are changed. Therefore, it is necessary to study on continuous k-NN query processing algorithm. In this paper, we propose both MCE-CKNN and MBP(Monitoring in Border Point)-CKNN algorithmss are S-GRID. The MCE-CKNN algorithm splits a query route into sub-routes based on cell and seproves retrieval performance by processing query in parallel way by. In addition, the MBP-CKNN algorithm stores POIs from the border points of each grid cells and seproves retrieval performance by decreasing the number of accesses to the adjacent cells. Finally, it is shown from the performance analysis that our CKNN algorithms achieves 15-53% better retrieval performance than the Kolahdouzan's algorithm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.169-177
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• 2007

Existing wireless access (mobile) routers are based commonly on the network address and port translation (NAPT) technique which permits simultaneously sharing a subscriber's connection to the network with multiple users. However, the NAPT architecturally makes the users invisible on the network side, thus becoming a user-oriented connection technique. In this paper, we propose a novel service provider-oriented unlicensed nomadic access relay station (WiNNERS) for helping wireless broadband network service providers to make their business more lucrative by accommdating unlicensed band users as subscribers into their network. The WiNNERS offers service providers the capability to directly manage each of the unlicensed band users at the network side. This direct management allows the service providers to flexibly and simply handle QoS, access control, and billing for each user. In order to distinguish each of the unlicensed band users the WiNNERS constructs a virtual tunnel from each user's terminal to the network access router using connection identifiers which is defined for service flow management within the WiBro system, Consequently, our proposed service provider-oriented relay station can be included into the WiBro network system with minimum modifications.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.335-341
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• 2014

To play the networked video contents in a client's mobile device in real time, the contents should be delivered to it by the contents server with streaming technology. Generally, in a server-client based commerce model, the server is in charge of both the authentication of the paid customer and distribution of the contents. The drawback of it is that if the customers' requests go on growing rapidly, the service quality would be degraded results from the problems of overloaded server or restricted network bandwidth. On the contrary, in P2P based networks, more and more the demand for service increasing, the service quality is upgraded since a customer can act as a server. But, in the P2P based network, there are too many servers to manage, it's possible to distribute illegal contents because the P2P protocol cannot control distributed servers. Thus, it's not suitable for commercial purposes. In this paper, the dymanic group authentication scheme is proposed which is suited to P2P based applications. The proposed scheme consists of group based key generation, key update, signature generation and verification protocols. It can control the seeder's state whether the seeder is joining or leaving the network, and it can be applied to hybrid P2P based commerce model where sales transactions are covered by the index server and the contents are distributed by the P2P protocol.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.445-453
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• 2005

Relative importance between bottom-up and top-down controls on phytoplankton dynamics was investigated in the Juam Reservoir, Chonnam based on the results from statistical analyses including regression and artificial neural network (ANN) modeling. Effects of nutrients on size-structured phytoplankton dynamics were explored by simple linear regression analysis and relative importance between bottom-up and top-down controls was estimated based on results from the artificial neural network analyses. Although there is a limitation in determining direct grazing effects since chlorophyll a : pheopigments ratios, indirect index for grazing activity rather than grazing rates or herbivores biomass were used, the results from regression analysis showed that nutrients especially orthophosphates were positively correlated with the phytoplankton biomass and chlorophyll a : pheopigments ratios were also positively correlated with the phytoplankton biomass at lower coefficient of determination ($r^2$) compared to orthophosphates. The simulation results from ANN suggested that the bottom-up mechanisms including water temperature and availability of nutrients, especially orthophosphates were more important than top-down mechanisms such as grazing in the phytoplankton dynamics.

• Journal of architectural history
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• v.19 no.3
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• pp.51-70
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• 2010

This paper aims to examine the constructional background and process of the Japanese military installations of Oiyang-po(外洋浦), especially based on the military secret documents. Furthermore, it aims to analyze the characteristics of the remains. The results are as follow; 1) The number of the Japanese military secret documents concerning with the installations of Oiyang-po, summed up to 33s. Especially, 14 documents about the expropriation of the lands and houses, and the constructions of the artillery position are reserved in "Mildae-ilgi"(密大日記)written from 1893 to 1942. 2) Imperialist Japan constructed firstly the military installations of Oiyang-po against the Russo-Japanese War. After the moving of the artillery headquarters into Masan in 1911, these installations had been maintained for the defense of Busan and Jinhae Bays. 3) As soon as 1904, the lands and houses of Oiyang-po were forcibly expropriated according to (韓日議定書). The Korean Government payed the expropriation prices to the dwellers. But the amount of money were too small and were lately payed. Moreover the dwellers' fishery right were never recompensed. 4) In 1904, the artillery headquarters and position were constructed by the 3rd Chookseong-dan(築城團) under the command of Matsui, a military engineer officer. The executional constructions were accomplished by the Japanese construction contractors. 5) After the moving of the artillery headquarters into Masan in 1911, the 3rd Chookseong-dan had usually repaired and consolidated the explosive warehouses and artillery facilities. 6) The artillery position constructed with the thick concrete walls was located at the foot of the mountain in back. It's plan was similar to the rectangular shape. It reserved six 280㎜ howizers and several explosive warehouses. 7) The reserve funds and arsenal funds were used for the constructions. And the items of expenses such as the establishments of the electric lights and communication networks, and the repairs of the explosive warehouses were mainly recoded in "Mildae-ilgi".

• International Journal of Oral Biology
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• v.33 no.4
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• pp.179-186
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• 2008

Several lines of evidence suggest that osteocytes play a critical role in bone remodeling. Both healthy and apoptotic osteocytes can send signals to other bone surface cells such as osteoblasts, osteoclasts, osteoclast precursors, and bone lining cells through canalicular networks. Osteocytes responding to mechanical strain may also send signals to other cells. To determine the role for osteocytes an mechanical strain in bone remodeling, we examined the effects of fluid flow shear stress on osteoclast precursor cell and osteoblast proliferation and recruitment induced by osteocytes. In addition, the effects of fluid flow shear stress on osteocyte M-CSF, RANKL, and OPG mRNA expression were also examined. MLO-Y4 cells were used as an in vitro model for osteocytes, RAW 264.7 cells and MOCP-5 cells as osteoclast precursors, and 2T3 cells as osteoblasts. MLO-Y4 cells conditioned medium (Y4-CM) was collected after 24h culture. For fluid flow experiments, MLO-Y4 cells were exposed to 2h of pulsatile fluid flow (PFF) at 2, 4, 8, $16{\pm}0.6\;dynes/cm^2$ using the Flexcell $Streamer^{TM}$ system. For proliferation assays, MOCP-5, RAW 264.7, and 2T3 cells were cultured with control media or 10-100% Y4 CM. Cells were cultured for 3d, and then cells were counted. RAW 264.7 and 2T3 cell migration was assayed using transwells with control media or 10-100% Y4-CM. M-CSF, RANKL and OPG in MLO-Y4 mRNA expression was determined by semiquantitative RT-PCR. Y4-CM increased osteoclast precursor proliferation and migration, but decreased 2T3 cell proliferation and migration. CM from MLO-Y4 cells exposed to PFF caused decreased RAW 267.4 cell proliferation and migration and 2T3 migration compared to control Y4-CM. However, Y4-CM from cells exposed to PFF had no effect on 2T3 osteoblastic cell proliferation. PFF decreased RNAKL mRNA and increased OPG mRNA in MLO-Y4 cells compared to control(without PFF). PFF had no effect on M-CSF mRNA expression in MLO-Y4 cells. These results suggest that osteocytes can regulate bone remodeling by communication with osteoclast precursors and osteoblasts and that osteocytes can communicate mechanical signals to other cells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.509-517
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• 2020

This study examined Sino-globalization through the network analysis of Chinese immigrants, international students, and travelers. The data were collected from the United Nations for immigrants, UNESCO for international students, and Ministry of Culture and Tourism of China for travelers. Consequently, Chinese immigrants and international students' favorite destinations were advanced Western countries, and Chinese travelers showed a high preference for Asian regions. Specifically, Thailand was the most popular destination for traveling, while the U.S. appeared to be the main destination for Chinese immigrants and students. The QAP analysis results showed a statistically significant correlation between the immigrant network and international student network. MR-QAP analysis found a causal relationship between the two networks. These findings may serve as empirical evidence for the Chinese government to review potential opportunities and problems related to Sino-globalization and provide the basis for preparing policy measures for other countries. Subsequent studies should compensate for research limitations by analyzing specific factors affecting national choice of Chinese immigrants, students, and travelers. The economic, social, and cultural impacts of China's globalization on other countries need to be discussed using qualitative research.

• Cartoon and Animation Studies
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• s.20
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• pp.1-14
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• 2010

The success of a three-dimensional blockbuster movie, AVARTA, brought an public attention on the expansion of three-dimensional computer applications, and it allows experts predict further hardware technology developments to support the such applications. Futhermore, an internet based infra structure and three-dimensional structure, third generation network community, advanced computer networks have influenced advancement in computer technology within the 3D game industry and the spread of 2D computer animation technologies. This advancement of computer technologies allow the industry to overcome a limitation of generating cultural design contexts existed within 2D network community. However, despite of the expansion of 2D and 3D computer technologies, a limitation of analysing designers' intentions on morphology of digital contents and user interface still exists. Therefore, the purpose of this study is to analyze (1) present conditions of the 3D industry and (2) protocols of designers' cognitive design processes based on their design communication, contents, and tools. Analysis was conducted based on literature reviews and case precedent analyses. For the analysis, a 2D Avarta sketch character was designed and then applied into a 3D game system. Observations how designers solve cultural problem within the structure via Avarta were conducted. Outcomes were then coded for further analysis.

• Journal of KIISE:Information Networking
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• v.33 no.4
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• pp.333-342
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• 2006

The cdma2000 lxEV - DO mobile communication system provides broadcast and multicast services (BCMCS) to meet an increasing demand from multimedia data services. The servicing of video streams over a BCMCS network must, however, face a challenge from the unreliable and error-prone nature of the radio channel. The BCMCS network uses Reed-Solomon coding integrated with the MAC protocol for error recovery. We analyze this coding technique and show that it is not effective in the case of slowly moving mobiles. To improve the playback quality of an MPEG-4 FGS video stream, we propose the Hybrid error recovery scheme, which combines Reed-Solomon with ARQ, using slots which are saved by reducing the Reed-Solomon coding overhead. The target packets to be retransmitted are prioritized by a utility function to reduce the packet error rate in the application layer within a fixed retransmission budget. This is achieved by considering of the map of the error control block at each mobile node. The proposed Hybrid error recovery scheme also uses the characteristics of MPEG-4 FGS (fine granularity scalability) to improve the video quality even when conditions are adverse: slow-moving nodes and a high error rate in the physical channel.