• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.207-214
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• 2005

After more than 100 years of development, rotating electric machines are a mature industrial product. Nevertheless, improvements are still possible for specific applications, and it is likely that the major evolution will be promoted by new materials and unconventional structures. Till now, plastic materials are an infrequent choice for the electric machines structural parts, but pioneering applications, such as aeronautical components, let some technological scouting: a low-weight/high-efficiency plastic axial flux motor for a solar flying platform is presented as an example of combined new-material/new-geometry development. The basic design aspects and the prototyping choices are presented and discussed together with the first experimental results.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.169-176
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• 2000

The partial discharge(PD) signal, may seems to be stochastic and merely random, was investigated using the method to discern between chaos and random signal, e.g. correlation integral, Lyapunov characteristic exponents and etc. For the purpose of obtaining experimental data, partial discharge detecting system via computer aided acoustic sensor, detect PD signal from the insulating system, was used. While this method is very different from typical statistical analysis from the point of view of a nonlinear analysis, it can provide better interpretable criterion according to the time evolution with a degradation process in the same type insulating system.

• Electronics and Telecommunications Trends
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• v.26 no.3
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• pp.25-36
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• 2011

지난 수십 년 간 인터랙션은 여러 분야에서 주목을 받아왔다. 그 중, 콘텐츠 분야에서 콘텐츠와 사용자 간의 인터랙션은 게임과 교육 분야를 중심으로 활발히 발전되어, 이제는 게임/교육 분야 이외의 콘텐츠 영역으로 확장되고 있다. 본 문서에서는 디지털 콘텐츠가 왜 인터랙티브 콘텐츠로 진화되었는지 고찰하고, 현재 나온 인터랙티브 콘텐츠들과 인터랙션을 위한 다양한 인터페이스들을 살펴본다. 또한, 인터랙티브 콘텐츠가 큰 영향력을 가질 가능성을 보여주는 몇몇 사례들을 주목할 만한 콘텐츠라는 제목 하에 소개한다. 마지막으로 인터랙티브 콘텐츠가 앞으로 어떻게 진화되어 갈지, 어떤 주제에 초점을 맞추어야 인터랙티브 콘텐츠 분야의 영향력이 극대화될지에 대한 방안을 제안하며 글을 맺는다.

• Journal of Communications and Networks
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• v.17 no.1
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• pp.27-33
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• 2015

In this paper, we consider a joint frequency-domain scheduling and user-pairing problem for virtual MIMO in the single carrier frequency division multiple access (SC-FDMA) system, e.g., the uplink transmission for third generation partnership project-long term evolution (3GPP-LTE) standard. Due to the subcarrier adjacency constraint inherent to SC-FDMA, its complexity becomes unmanageable. We propose a greedy heuristic algorithm for PF scheduling so as to deal with the complexity issue in this joint problem. It has been shown that its performance can reach up to 90% of its upper bound.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.215-218
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• 2006

A study was made to investigate microstructural evolution and mechanical properties of ultra-fine grained (UFG) pure-Ti produced by equal channel angular (ECA) pressings. The deformed structures were analyzed by finite element method and transmission electron microscopy with the increment of straining. After 4 isothermal ECA pressings, initial coarse grains ($30{\mu}m$) were significantly refined to ${\sim}0.3{\mu}m$ with homogeneous distribution of microstructure which was resulted from $180^{\circ}$ rotation of the sample between pressings. UFG pure-Ti exhibited the considerable improvement in yield strength while losing strain hardening capacity as compared to coarse grained microstructure at ambient temperature, which was mainly attributed to ultra-fine grain microstructure with non-equilibrium grain boundaries.

• ETRI Journal
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• v.38 no.3
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• pp.463-468
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• 2016

With the constant increase in network traffic, wireless operators are finding it more challenging to keep network hardware costs to a minimum. At the same time, the energy cost associated with operating a network has increased proportionally. Therefore, the search for higher network capacity is simultaneously accompanied by the search for a cost-efficient network deployment. In this paper, we show that a saving in transmitted signal energy can be achieved at the signal design level by deploying very specific signal processing techniques. Using an orthogonal frequency-division multiplexing signal for Long-Term Evolution networks as an example, we utilize a novel non-uniform companding quantizer to save a transmitted signal energy. Our results show that by using non-uniform quantization it is possible to further optimize 4G wireless networks.

• Animal Systematics, Evolution and Diversity
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• no.nspc3
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• pp.93-100
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• 1992

Seven geographical variation types of G.sobaegensis in South Korea were reported by Kim and Lee(1977) and Lee and Kim (1980). After extensive reexamination, we considered type 4, one of the variation types collectd from various localities of Kyongsangbuk-do Pongwha-gun, as a new species This new species is named as Gammarus longisaeta and fully described and illustrated. Adding this new species, total 9 species of freshwater Gammarus are Known to Korea.

• Animal Systematics, Evolution and Diversity
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• v.23 no.2
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• pp.127-133
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• 2007

A new genus Goodingius is proposed to incorporate Hemicyclops adhaerens(Williams), H. arenicolae Gooding, H. elongatus Wilson and H. subadhaerens Gooding, all of which bear the six-segmented female urosome, three mandibular elements (or three elements plus one rudimentary setule), five setae on the first antennular segment, and no inner coxal seta of leg 4. The genus Giardella Canu, a sister taxon of Goodingius, is redefined as possessing eight elements on the third exopodal segment of leg 3, only a single inner seta on the second endopodal segment of leg 4, four spines on the third endopodal segment of leg 4. To the genus Giardella, Hemicyclops caissarum Kihara and Rocha and H. carinifer Humes are assigned, in addition to Giardella ricoensis n. sp., Giardella callianassae Canu, and G. thompsoni A. Scott. Keys to the species of both genera are provided.

• Journal of Korea Foundry Society
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• v.17 no.4
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• pp.379-384
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• 1997

Al-15Cu-lMg alloys have been directionally solidified in 3mm diameter alumina tubes under the conditions of $760^{\circ}C$ of furnace temperature and 12 cm/hr of furnace moving velocity(V). By analyzing the evolution of the temperature profiles along the alloy length, the position of the solid/liquid interface, temperature gradient(G) and local growth velocity (R) were determined. These growth characteristics were compared for 6, 10, 14 cm length alloys. Steady state growth region was obtained in 15 cm length alloy, not in 6, 10 cm.

• International Journal of Computer Science & Network Security
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• v.21 no.1
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• pp.152-161
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• 2021

The paper focuses on Device-to-device (D2D) Architectures evaluation frameworks. D2D communication and discovery can improve spectrum usage efficiency and optimize the tradeoffs between throughput and energy consumption. The target operation modes involve both indirect communication between two nodes via a base station or the direct communication among proximal nodes, enabling use cases that can support communications out of cellular coverage, as well as low end-end delay requirements. The paper will present the architectural evolution of D2D networks within 3GPP standardization and will highlight key network functionalities and signaling protocols. It will also identify key analytical and simulation models that can be used to assess the performance and energy efficiency of resource allocation strategies, and it will present a suitable cross-layer integrated framework.