• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.214-220
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• 2010

This paper presents the results of a study on an electrodeless high intensity discharge (HID) lamp system that is powered by circularly polarized microwaves (CPMs). The technique to generate CPMs enables an electrodeless high intensity discharge lamp to be turned on without the retation of the bulb but conventional electrodeless high intensity discharge lamps use rotating bulbs in order to prevent a puncture in a hot spots that are formed by the linearly polarized microwaves in the circular cavity. The technique to generate CPMs is described and the salient features of the lamp characteristics are presented.

• Journal of Communications and Networks
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• v.18 no.5
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• pp.773-783
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• 2016

Both coordinated multi-point transmission and frequency reuse are effective approaches to mitigate inter-cell interference and improve network coverage. The motivation of this work is to explore the manner to effectively utilize the spectrum resource by reasonably combining cooperation and frequency reuse. The $Mat{\acute{e}}rn$ cluster process, which is appropriate to model networks with hot spots, is used to model the spatial distribution of base stations. Two cooperative mechanisms, coherent and non-coherent joint transmission (JT), are analyzed and compared. We also evaluate the effect of multiple antennas and imperfect channel state information. The simulation reveals that the proposed approach to combine cooperation and frequency reuse is effective to improve the network coverage for users located at both the center and the boundary of the cooperative region.

• Journal of the Korean Society of Combustion
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• v.6 no.2
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• pp.29-35
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• 2001

Unsteady numerical study has been conducted on combustion dynamics of a lean-premixed swirl-stabilized gas turbine swirl injector. A three-dimensional computation method utilizing the message passing interface (MPI) parallel architecture, large eddy simulation(LES), and proper orthogonal decomposition (POD) technique was applied. The unsteady turbulent flame dynamics are simulated so that the turbulent flame structure can be characterized in detail. It was observed that some fuel lumps escape from the primary combustion zone, and move downstream and consequently produce hot spots. Those flame dynamics coincides with experimental data. In addition, basis modes of the unsteady turbulent flame are characterized using proper orthogonal decomposition (POD) analysis. The flame structure based on odd basis modes is apparently larger than that of even ones. The flame structure can be extracted from the summation of the basis modes and eigenvectors at any moment.

• Journal of the Korean Society of Combustion
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• v.23 no.1
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• pp.28-35
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• 2018

Entropy waves(or hot spots) in a gas turbine combustor are generated by irregular heat release from flames, then can be coupled with acoustic waves when they are accelerated at the exit of the combustor. This coupling mechanism between the entropy and the acoustic waves is generally known to be one of the triggers for combustion instability, which is commonly called "indirect" combustion noise. This paper reviews the fundamental theories on generation, propagation, and coupling with acoustic field of entropy waves and recent research results on the indirect combustion noise for gas turbine combustors.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.173-174
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• 2011

현대의 경찰활동은 지역사회 경찰활동(Community Policing)으로 귀결된다. 지역사회 경찰활동에 대한 많은 논의가 있어왔지만 지역사회 경찰활동이라는 패러다임에 관한 통합적인 모색은 등한시 되어 온 것이 사실이다. 지역사회 경찰활동에서 파생된 프로그램 및 전략들은 실질적인 경찰활동과 관련이 있다. 이러한 프로그램들은 경찰조직의 이슈 혹은 특정한 문제를 해결하기 위하여 지역사회 경찰활동보다 의도적으로 좁은 범위로 한정하고 있다. 그러한 초점을 가진 대표적인 프로그램은 문제지향적 경찰활동(Problem-oriented policing), 깨진 창(Broken Windows), 컴스탯(Comstat), 제3자 경찰활동(Third party policing), 우범지대(Hot spots)로 볼 수 있다. 그러나 이러한 프로그램 및 전략들은 매우 한정된 범위 내에서 존재하고 운영되는 것들이기 때문에 오늘날의 경찰활동의 근거나 기초를 지역사회 경찰활동만큼 제공해주지 못하고 있다. 지역사회 경찰활동과 관련된 경찰개혁 프로그램이나 전략들을 통합하여 다시 한 번 의미를 재정립하는 것은 현장의 경찰관들이 보다 쉽게 경찰행정의 의미를 이해하고 실제로 실현해 나갈 수 있는 방법을 안내하기 위함이다.

• Smart Structures and Systems
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• v.21 no.1
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• pp.99-111
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• 2018

Wind induced large bending oscillation amplitudes in tall and slender telecommunication steel towers may lead to precocious fatigue cracks and consequent risk of collapse of these structures, many of them installed in rural areas alongside highways and in highly populated urban areas. Varying stress amplitudes at hot spots may be attenuated by means of passive control mechanical devices installed in the tower. This paper gives an account of both mathematical-numerical model and the technique applied to design and evaluate the performance of a double controller installed in existing towers which is composed by a nonlinear pendulum and a novel type of passive controller described herein as a planar motion disk mounted on shear springs. Results of experimental measurements carried out on two slender tubular steel towers under wind action demonstrate the efficiency of the double controllers in attenuating the towers bending oscillation amplitudes and consequent stress amplitudes extending the towers fatigue life.

• Progress in Superconductivity and Cryogenics
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• v.1 no.2
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• pp.49-53
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• 1999

We fabricated a resistive superconducting fault current limiter (SFCL) with a shunt resistor in order to bypass the transient current at faults. The SFCL consists of a YBCO films coated with an Au layer (10$\Omega$ at room temperature). which is to disperse the heat generated at hot spots in the YBCO films, and a 5$\Omega$ shunt resistor. The minimum quench current of the SFCL was found to be 12.2Apeak. This SFCL successfully controlled the fault current to below 23 Apeak. Which is otherwise to increase up to 103 Apeak. With the shunt resistor, the temperature of the SFCL rose the temperature of the SFCL rose three times slower than without the shunt, whereby the SFCL is protected at high currents.

• Journal of Ocean Engineering and Technology
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• v.19 no.4 s.65
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• pp.21-27
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• 2005

Large welded structures, including ships and offshore structures, are normally in operation under cyclic fatigue loadings. These structures include many geometric discontinuities, as well as material discontinuities due to weld joints. The fatigue strength at these hot spots is very important for the structural performance. In the past, various Non Destructive Evaluation (NDE) techniques have been developed to detect fatigue cracks and to estimate their location and size. However, an important limitation of most of the existing NDE methods is that they are off line; the normal operation of the structure has to be interrupted, and the device often has to be disassembled. This study explores the development of a structural health monitoring system, with a special interest in applying the technique to welded structural members in ship and offshore structures. In particular, the impedance based structural health monitoring technique that employs the coupling effect of piezoceramic (PZT) materials and structures is investigated.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.87-91
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• 2009

Over the past several years both licensed and unlicensed services and devices have enjoyed extensive growth in the wireless marketplace. In some urban areas in the Kazakhstan, the penetration rate of licensed cellular and PCS services is more than 60%. Similarly, the use of unlicensed wireless local area network technologies has grown significantly as these systems have been deployed in homes, offices, and 'hot spots' in restaurants, hotels, public meeting areas, etc. As more services are wirelessly enabled and as technologies continue to evolve, the demand for new spectrum for commercial services will also continue to increase. Thus, the appropriate regulatory models for future spectrum allocations will continue to be debated throughout the wireless industry.

• Molecules and Cells
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• v.41 no.11
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• pp.933-942
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• 2018

Traditionally, small-molecule or antibody-based therapies against human diseases have been designed to inhibit the enzymatic activity or compete for the ligand binding sites of pathological target proteins. Despite its demonstrated effectiveness, such as in cancer treatment, this approach is often limited by recurring drug resistance. More importantly, not all molecular targets are enzymes or receptors with druggable 'hot spots' that can be directly occupied by active site-directed inhibitors. Recently, a promising new paradigm has been created, in which small-molecule chemicals harness the naturally occurring protein quality control machinery of the ubiquitin-proteasome system to specifically eradicate disease-causing proteins in cells. Such 'chemically induced protein degradation' may provide unprecedented opportunities for targeting proteins that are inherently undruggable, such as structural scaffolds and other non-enzymatic molecules, for therapeutic purposes. This review focuses on surveying recent progress in developing E3-guided proteolysis-targeting chimeras (PROTACs) and small-molecule chemical modulators of deubiquitinating enzymes upstream of or on the proteasome.