• Journal of Digital Convergence
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• v.7 no.1
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• pp.125-136
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• 2009

SK Communications entered Korean instant messenger market as a late-mover in 2001 and its instant messenger service "NateOn" was placed in competition with Microsoft's "MSN Messenger", the leading service provider at the time. NateOn studied the nature of users accurately and gradually increased its market share through various services, and in September 2005, it succeeded in overtaking MSN as No.1 in the market. The success of NateOn is a case where a late-mover overcame the buddy-list network, a powerful competitive advantage, of the incumbent. By studying the changes in the instant messenger market of Korea, we try to examine the causes of NateOn's victory and MSN's loss. Through this, we wish to give implications for managers who endeavor to discover the internal and external strategies the leading business has to implement to remain ahead, and how a late-mover can overcome the lack of resources and capacity to leave a mark in the market.

• Journal of Korean Port Research
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• v.13 no.2
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• pp.199-214
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• 1999

Recently leading edge companies use the Supply Chain Management as a competitive weapon to secure and maintain customer loyalty. As a consequency they are concentrating resources on the company’s core business and employing strategic alliances with third-party providers to ensure the company provides its customers’desired logistics service levels at acceptable costs. Under this circumstances this paper surveys the third party logistics as a leading edge logistics industry coping with the progress of the supply chain management. The status and the type of the TPL including the Forwarder are analyzed in the view point of global logistics. Also the development strategy of third party logistics in the future is suggested.

• Journal of Power Electronics
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• v.16 no.3
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• pp.883-893
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• 2016

This paper presents a comprehensive analysis of the spurious turn-on phenomena in phase-shifted full-bridge (PSFB) converters. The conventional analysis of the spurious turn-on phenomenon does not establish in the PSFB converter as realizing zero voltage switching (ZVS). Firstly, a circuit model is proposed taking into account the parasitic capacitors and inductors of the transistors, as well as the parasitic elements of the power circuit loop. Second, an exhaustive investigation into the impact of all these parasitic elements on the spurious turn-on is conducted. It has been found that the spurious turn-on phenomenon is mainly attributed to the parasitic inductors of the power circuit loop, while the parasitic inductors of the transistors have a weak impact on this phenomenon. In addition, the operation principle of the PSFB converter makes the leading and lagging legs have distinguished differences with respect to the spurious turn-on problems. Design guidelines are given based on the theoretical analysis. Finally, detailed simulation and experimental results obtained with a 1.5 kW PSFB converter are given to validate proposed analysis.

• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.101-107
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• 2009

In this study 1,079 occupational accident reports were used to examine the characteristics and causes of occupational injuries in the small-sized textile companies with less than 50 employees. These data were analyzed in terms of age of injured person, work experience, accident type, injury type, and agency of accident. The results show that there are some patterns: (1) injuries occur more frequently in the 40~49yr age group; (2) about half of all accident occurred during the first year of employment; (3) there is a higher percentage of sick people leaving in the 29~90day range; (4) 'caught in and between objects' represents the leading accident type; (5) the most common type of incidence is related to the machinery; (6) 'lower back injuries' is the leading type of occupational disorder. These results can be used to develop more effective accidental occupational injury prevention programs for small-sized textile industries.

• Journal of architectural history
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• v.19 no.6
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• pp.173-186
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• 2010

This article is about the study on construction contractors in Daegu during the Japanese Colonial Rule. The first construction contractors who involved with Kyong-bu railroad work in 1904 personally. But, after they go through the bidding method, changed by the Japanese Government General of Korea in 1922, and the second bid rigging in 1932, contractors was changed gradually the organization into unlimited partnership, limited partnership or stock corporation. The number of them was increased. Most contractors were Japanese, and organized a limited partnership which has been capitalized at 30,000 won. On the other hand, Korean contractors couldn't work at an important part, except for the personal activities of Youngsil Lee(李永實). They were usually employed as consultants or field deputies by Japanese contractors. After the Liberation, Japanese construction contractors returned to Japan, however Tatuoka-kumi(龍岡組), Yasiro-kumi(屋代組) and Sakano-kumi(坂野組) that was leading the business which were took over by Koreans. They were leading architecture field in Daegu.

• Journal of Families and Better Life
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• v.29 no.6
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• pp.123-136
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• 2011

Korean workplaces can and should reflect the realities of the 21st century workforce. Leading companies try to plan and implement family-friendly policies for their employees, but most of them in fact do not offer family-friendly policies or offer only a few such policies. Therefore, this study seeks to suggest policies that can lead to better family-friendly cultures at workplaces. A family-friendly company culture allows for a better work-life balance, including flexible schedules and generous family-leave policies. This study suggests a family-friendly committee for work-life balance and a role for the government as a leading organization.

• The Korean Journal of Ecology
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• v.21 no.5_2
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• pp.541-547
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• 1998

The flora and vegetation of the alpine grassland at Dalmoon on Mt. Paektu were investigated on July 24, 1997 by 1 m ${\times}$ 1 m quadrat method. The flora of the vascular plants investigated on this alpine grassland was 36 taxa belonging to 17 families, 35 genera, 29 species, 3 subspecies, 4 varieties. Te leading families were Compositae (7 taxa) and Gramineae (4 species), and the forb was more than the grass. Four dwarf shrubs which were Salix metaformosa, Dryas octopetala var. asiatica, Rhododendron aureum and Vaccinium vitis-idaea were found at the studied sites. This alpine grassland was composed of 17 communities, Astragalus uliginosus, Sanguisorba sitchensis, Deschampsia caespitosa were dominated over 18, 5 and 4 quadrats, respectively.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.119-125
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• 1998

In long vertical duct, the aspect of second flame in laminar flame propagating through lycopodium-air mixtures and the behavior of dust particles in neighborhood in front of flame have been examined experimentally. In order to trace the development of second flame to its origin, the velocity and vorticity distribution of dust particles in front of flame were measured by using with the real-time PIV system. The velocity of particles was approximately zero at the central part of flame front and the ahead of the flame leading edge, but maximum near the duct wall. The flame velocity of second flame and the movement of leading flame edge depend mainly on behavior of dust particles by the flow distribution of temperature and pressure.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.83-90
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• 2002

An experimental study was conducted to investigate the effects of a leading edge extension(LEX) on the vortex flow field over a delta wing by measuring the total pressure distribution in a subsonic wind tunnel. Freestream velocity was 40m/sec and Reynolds number per meter was $1.76{\times}10^6$. The wing with the LEX experienced a strong interaction between the LEX and wing vortices. As the angle of attack increased, the coupled vortex field of these two vortices maintained its strength and concentricity much better than the vortex field over the wing without the LEX.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.116-123
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• 2005

An experimental investigation on the static and dynamic stall characteristics of elliptic airfoil was performed by PIV velocity field measurements. The flow Reynolds number was $3.13{\times}10^5$ and the reduced frequency of the pitch oscillation ranged from 0.075 to 0.125. The onset of static stall was caused by boundary layer separation which started at the trailing edge and progressed toward the leading edge. However, dynamic stall was caused by the vortex shed at the leading edge region and the flow field showed a vortex dominated flow with turbulent separation and alternate vortex shedding. The increase of reduced frequency increased the dynamic stall angle of attack and intensified the flow hysteresis in the down-stroke phase.