• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.73.2-73.2
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• 2012

Matusoka & Kawara (2010) showed that the number density of the most massive galaxies (log $M/M_{\odot}=11.5-12.0$) increases faster than that of the next massive group (log $M/M_{\odot}=11.0-11.5$) during 0 < z < 1. This appears to be in contradiction to another important empirical concept of "downsizing". We attempt to understand the two observational findings in the context of the hierarchical merger paradigm using semi-analytic techniques. Our models closely reproduce the result of Matusoka & Kawara (2010). Downsizing can also be understood as larger galaxies have on average smaller assembly ages but larger stellar ages. Our fiducial models further reveal the details on the history of stellar mass growth of massive galaxies. The most massive galaxies (log $M/M_{\odot}=11.5-12.0$ at z=0), which are mostly brightest cluster galaxies, obtain roughly 70% of their stellar components via merger accretion. The role of merger accretion monotonically declines with galaxy mass: 45% for log $M/M_{\odot}=11.0-11.5$ and 20% for log $M/M_{\odot}=10.5-11.0$ at z = 0. The specific accreted stellar mass rates via galaxy mergers decline very slowly during the whole redshift range, while the specific star formation rates sharply decrease with time. In the case of the most massive galaxies, merger accretion becomes the most important channel for the stellar mass growth at z ~ 2. On the other hand, in-situ star formation is always the dominant channel in the $L_*$ galaxies.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.185-189
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• 2008

Practical pattern recognition systems should overcome very large class problem. Sometimes it is almost impossible to build every model for every class due to memory and time constraints. For this case, grouping similar models will be helpful. In this paper, we propose GMC(Group Model Clustering) to build a large class Chinese character recognition system. We built hidden Markov models for 10% of total classes, then classify the rest of classes into already trained group classes. Finally group models are trained using group model clustered data. Recognition is performed using only group models, in order to achieve reduced model size and improved recognition speed.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.381-387
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• 2016

Many efforts have focused on the improvement of power density and efficiency by downsizing the motor and inverter. Recently, Toyota, Honda, and GM realized that the compact-sized motor uses the hairpin structure with increased space factor. Reducing the maximum torque from high-speed technique also makes it possible to design the high-power density model. Toyota and Honda used the newly developed power semiconductor IGBT to decrease conduction loss for high-efficiency inverter. In particular, Toyota used the boost converter to increase the DC link voltage for high efficiency in low-torque high-speed region. Toyota and GM also used the double-sided cooling structure for miniaturization of inverter for high-power density.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.249-249
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• 1997

최근에 등장한 ERP system은 전사 자원을 통합 관리하여 생산성과 효율성을 크게 향상시켜 줄뿐만 아니라, package로 되어 있어 단기간에 system을 구축할 수 있게 해준다 는 측면에서 획기적인 system으로 많은 기업들의 주목을 받고 있다. ERP 뇬?은 C/S system으로의 downsizing, networking, internet/intranet, BPR의 수행, EIS 등 최근의 정보 기술을 망라하고 있기 때문이다. 그러나 module화된 package를 도입하기 위해서는 process를 package에 맞추어 줘야 하므로 필연적으로 BPR이 따르며 실제 도입사례를 보 더라도 system에 들어간 직접비용보다 표준화를 포함한 process 설계에 투자된 노력이 훨 씬 더 많다. 이제까지의 경험으로 볼 때, BPR은 성공보다 실패 확률이 더 높다. BPR의 실 패는 ERP system 도입에 치명적이다. BPR이 지금처럼 실패를 거듭한다면 ERP 또한 많은 장점에도 불구하고 성공하기 어렵다고 하겠다. 따라서 본 연구에서는 성공적인 ERP 도입을 위한 전제조건으로서의 process 재설계를 가로막는 요인은 무엇이며, 이를 극복하기 위한 대안으로서의 전략은 어떠해야 하는지 제시하고자 한다.

• Communications of Mathematical Education
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• v.19 no.4 s.24
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• pp.649-670
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• 2005

The university mathematics education has been in a crisis during the last 10 years. In recent years, the crisis is rapidly amplified with a science-engineering student resource downsizing. In korea, government and industry have intervent several supporting policies to treat the mathematics-science-engineering crisis in university education. In this article, policies and its contents about human reasource development, industry-university co-ops, national skills standards are presented in context of university mathematics education.

• Korean Journal of Child Studies
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• v.30 no.6
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• pp.405-416
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• 2009

Almost 18,000 children were protected in 285 residential facilities all over the country in 2008 in Korea. The recent trends of the residential care include downsizing, and emphasizing independent living programs for aging out youths. Since the 1990s when the active research on the children in residential facilities has begun, the study focus has extended to the issues of developmental status and outcomes of the children, and recently, to the independency of the youths discharged from the facilities. The practical and policy issues are development of therapeutic programs for the children in care, increase of counseling staff, extension of programs for restoring children's relationship with their families, and planning of various policies to support the independence of discharged youths.

• Proceedings of the Korea Database Society Conference
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• 1994.09a
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• pp.9-16
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• 1994

Author outlines briefly developments of policies relating to telecommunication infrastructure and databases since latter half of 1970′s. There exist three phases. The first phase was from later 1970′s to 1985, which was an initial stage of electronic information service in Japan. In the second phase, 1985～1990, basic policy change made possible the privatization of telecommunication services and proliferation of database products and vendors, The third phase began in early 1990′s with downsizing in computer usage, wide-spreading information networks and rapid dissemination of personal computers. Then author describes offers on policy formation for "novel information infrastructure" and current situation concerning the "Internet" in Japan. Finally, tasks and problems for implementing new generation program for information infrastructure and database usage are pointed out, These are knowledge resource, cost, copyrights and cultural problems including language.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.3
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• pp.255-261
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• 2018

High power trends in the diesel engines due to engine downsizing do not provide noise attenuation that can be satisfied with the performance of the existing silencer on account of high frequency increases in the exhaust noise. This study improves the attenuation performance of the exhaust silencer of the diesel engine and suggests silencer structure that performs best attenuation performance, especially at the high frequency range in the exhaust noise. It proposes dual silencer structure with an average attenuation performance of 6.4 dB and a maximum of 10.7 dB in the high frequency range (over 500 Hz), and analyzes its characteristics compared with the existing silencer. The performance analysis is performed according to 'Measurements on silencers in situation-ISO 11820:1996 Acoustics' and describes the results of comparative analysis with the existing silencer.

• International Journal of Korean Welding Society
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• v.5 no.1
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• pp.53-59
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• 2005

Auto industry has employed resistance spot welding(RSW) to join steel sheets for structural rigidity of automobile body. Driven by the need to reduce weight and fuel consumption, car companies have been evaluating aluminum intensive vehicles(AIVs) as a way to reduce vehicle weight without downsizing. During the transition from all steel-construction vehicle body to aluminum intensive body, joining aluminum to steel sheets emerges as a serious contender in automobile body. This paper deals with application of transition material to RSW aluminum to steel. Placing transition material insert between the aluminum/steel interface was found very effective to overcome physical incompatibility between aluminum and steel. Use of transition insert allows for two separate weld nuggets to be formed in their respective aluminum/aluminum and steel/steel interfaces. This RSW processes was monitored with the aid of dynamic resistance sampling. Typical patterns in sampled dynamic resistance curves indicated formation of sound nugget. The growth of two separate nuggets was examined by micro-cross section test.

• Journal of Navigation and Port Research
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• v.35 no.7
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• pp.589-596
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• 2011

Terminal market has rapidly crashed and market rates have taken a sharp plunge. The substantial throughput decrease resulted from the world economic downturn has been a finishing blow to the terminal operators in Busan. Every terminal operator is taking cost saving as its first priority and accelerating structural reform and downsizing. Under the desperate situation, the need of effective cost analysis would be highly required to effectively control operation cost and to develop new services to satisfy the different needs of the customers. Furthermore, terminal operators could reduce unnecessary activities and concentrate their resource on the more cost-effective process through the operation cost analysis. In order to suggest a new framework of the cost control of container terminals, this paper seeks to analyze terminal costs based on ABC approach by processing actual data.