• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3841-3861
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• 2017

Virtualized small cell network is a promising architecture which can realize efficient utilization of the network resource. However, conventional full duplex self-backhauls lead to residual self-interference, which limits the network performance. To handle this issue, this paper proposes a virtual resource allocation, in which the residual self-interference is fully exploited by employing a physical-layer network coding (PNC) aided self-backhaul scheme. We formulate the features of PNC as time slot and information rate constraints, and based on that, the virtual resource allocation is formulated as a mixed combinatorial optimization problem. To solve the problem efficiently, it is decomposed into two sub problems, and a two-phase iteration algorithm is developed accordingly. In the algorithm, the first sub problem is approximated and transferred into a convex problem by utilizing the upper bound of the PNC rate constraint. On the basis of that, the convexity of the second sub problem is also proved. Simulation results show the advantages of the proposed scheme over conventional solution in both the profits of self-backhauls and utility of the network resource.

• Asia pacific journal of information systems
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• v.29 no.3
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• pp.382-406
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• 2019

We study the antecedents to tie formation on an (Facebook-like) enterprise social media platform implemented to support cross-boundary connections. Research has produced mixed findings regarding the role of social media in cultivating bridging vs. closed networks. We examine the tie formation patterns of 1,386 enterprise social media users over a two-year period. Specifically, we observe who became (or chose not s become) "friends" with whom at the dyadic level and relate the decisions to various mechanisms that affect one's network to expand, constrain, or bridge. Using logistic and OLS regressions, we find that users tend to form ties via reciprocity and transitivity (with friends of friends), both of which help expand one's network. We also find strong networking tendency toward functional and hierarchical homophily (same business unit and same rank, respectively), which is likely to constrain one's network (closed network structure). We find that one's participation in various online interest groups is likely to open one's network (bridging network structure) while no evidence found for preferential attachment. Overall, we find that enterprise social media offers features, some of which are likely to foster bridging while others foster closed networks via different mechanisms.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1459-1460
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• 2011

• Architectural research
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• v.15 no.2
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• pp.77-86
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• 2013

Cohousing is based on collaborative network, or fictive kin in the community. It could facilitate the goal of self-sufficiency. This research aims to investigate the motivation of move to cohousing communities in Sweden, and to find out if there are any significant differences according to two different cohousing types; between the +40 cohousing and the mixed-age cohousing. The +40 cohousing is a kind of senior cohousing in which residents are supposed to be aged over 40. Questionnaire survey was applied and 242 collected data were analyzed by SPSS statistical program. Notable differences in demographic and dwelling variables are found between the 2 groups. There are more women, singles, academics, and small dwellings in the +40 cohousing than in the mixed-age cohousing. Referring motivation of move, "sharing common activity" and "idea of cohousing" are commonly noticed as the main reasons why people move to cohousing communities. Major difference between the 2 groups is that residents of the +40 cohousing tend to stress more on social interaction with neighbors than practical merit. On the contrary, ones of the mixed-age cohousing focus more on practical advantage than social interaction. As a conclusion, it is evident that motivation of move to cohousing communities is different by cohousing types, which have different residents' characteristics. Cohousing could contribute to elevate marginal group's quality of life as an alternative living environment. Therefore, cohousing design has to be tailored to adapt residents' specific needs of different life-stages. In order to implement cohousing model into other countries, for instance into Korea, it needs to experiment with the notion of transplanting selected cohousing principles to a public housing development. In the mixed-age cohousing where more dual income families with young children than conventional housing developments reside, residents would need more practical advantage than emotional support in the community, while as residents in the senior cohousing need vice versa.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.253-264
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• 2018

The GPS radiosonde is designed to conduct a full synoptic sounding to balloon burst using data generated from precision meteorological sensors and the GPS satellite network. The GPS radiosonde include proven, accurate temperature, humidity and capacitance aneroid pressure sensors. The atmospheric boundary layer was intensively observed in three islands of the west sea from 18 LST on March 9, 2016 to 06 LST on March 12, 2016. We investigated the restriction of nocturnal stable layer and rather the development of the mixed layer at night. On March 9, nocturnal mixed layer was developed by buoyancy heat flux. On the other hand, on March 10, the shear production was higher especially at 21 LST when the mixed layer height was the highest during the intensive observation period. The wind shear and the surface heat flux which produce the turbulent kinetic energy played an important role to grow the mixed layer even at night.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.1-4
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• 2001

The classification performance of Artificial Neural Network (ANN) and RBF-NN was compared for Landsat TM image. The RBF-NN was validated for three unique landuse types (e.g. Mixed landuse area, Cultivated area, Urban area), different input band combinations and classification class. The bootstrap resampling technique was employed to estimate the confidence intervals and distribution for unit load, The pollutant generation was varied significantly according to the classification accuracy and percentile unit load applied. Especially in urban area, where mixed landuse is dominant, the difference of estimated pollutant load is largely varied.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.157-166
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• 2008

There has been a renewal of interest in management of underground facility in recent years. As several research have been made on management for underground facility of waterworks pipe. In this paper smart-tag is defined and applied to requiring ubiquitous environment. Also, GPS is essential technology for the implementation of proposed program, which has GPS and RFID mixed business model. And it manages data of underground facility with RFID system effectively and provides the high quality practical effectiveness of entire system through GPS receiving module and network communication on GIS. In conclusion, this paper proposed applications management system with location mixed database. Proposed database and interface skill is tested and evaluated through the simulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.79-83
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• 2018

An accurate method to measure shielding effectiveness(SE) of EMI spray coating film is presented. After high frequency simulating, Circular coaxial standard test fixture is fabricated. A sample of EMI spray coating film was fabricated for insertion into a circular coaxial standard test fixture. The measuring instrument used an Agilent 8722ES vector network analyzer for the SE measurement. The exact SE of copper and silver mixed spray coating sample was measured by the composition of the measuring instrument and the measuring sample. The SE of copper sample was measured at 70 dB and the SE of copper and silver mixed spray coating sample was measured at 60 dB. As a result of the measurement, the reliability of the circular coaxial standard test fixture was confirmed.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1534-1541
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• 1996

Routing security is the confidentiality of route taken by the data transmitted over communication networks. If the route is detected by an adversary, the probability is high that the data lost or the data can be intercepted by the adversary. Therefore, the route must be protected. To accomplish this, we select an intermediate node secretly and transmit the data using this intermediate node, instead of sending the data to a destination node using the shortest direct path. Furthermore, if we use a number of secret routes from a node to a destination node, data security is much stronger since we can transmit partial data rather than entire data along a secret route. Finally, the idea above is implemented on MRNS Network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.1
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• pp.89-95
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• 2006

Planning distributed manufacturing logistics is one of main issues in supply chain management. This paper proposes a hybrid heuristic approach for the Multi-Level, multi-item Capacitated Lot Sizing Problem (MLCLSP) in supply chain network. MLCLSP corresponds to a mixed integer programming (MIP) problem. With integer variable solutions determined by heuristic search, this MIP problem becomes linear program (LP). By repeatedly solving the relaxed MIP problems with a heuristic search method in a hybrid manner, this proposed approach allocates finite manufacturing resources fur each distributed facilities and generates feasible production plans. Meta heuristic search algorithm is presented to solve the MIP problems. The experimental test evaluates the computational performance under a variety of problem scenarios.