• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.482-487
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• 2007

자발적 컴퓨팅은 인터넷의 연결된 가정 혹은 사무실의 PC를 집적하여 고성능 컴퓨팅을 창출하고자 하는 것이 목표이다. 이는 많은 자원제공자가 참여할 수 있도록 확장성이 보장되어야 한다. 하지만 기존의 자발적컴퓨팅 시스템에서는 중앙관리서버에 의해서만 작업분배가 이루어지므로 서버의 병목현상이 발생하게 된다. 본 논문에서는 결함포용에 사용되는 중복수행기법을 이용하여 P2P기반의 중복작업분배기법을 제안한다. 제안하는 P2P기반 중복작업분배기법은 서버의 병목현상을 줄이고, 서버의 결함 시에도 일정시간 서비스를 유지할 수 있는 강건함을 보였다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2835-2844
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• 1998

Most data parallel languages provide the block-cyclic distribution (cyclic(k)) that is one of the most general regular distributions. In order to generate local addresses for an array section A(l:h:s) with block-cyclic distribution, efficient compiling methods or run-time methods are required. In this paper, two local address generation methods for the block-cyclic distribution are presented. One is a simple scan method that is modified from the virtual-block scheme. The other is a linear-time ${\Delta}M$ table that contains the local memory access information construction method. This method is simpler than other algorithms for generating a ${\Delta}M$ table. Experimental results show that a simple that a simple scan method has poor performance but a linear-time ${\Delta}M$ table generation method is faster than other algorithms in ${\Delta}M$ table generation time and access time for 10,000 array elements.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.12-31
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• 2010

The objective of this study is to evaluate the applicability of GIS based multi-directional flow allocation model. In order to evaluate the suggested model in this study, it was applied to real watersheds, Pyeongchang and Soyang river basin. The simulation results were compared with observed values, and showed good agreements. The improvement of accuracy and reduction of simulation time were carried out by applying multi-directional flow allocation. Accordingly, the applied methodologies presented in this study will be used to predict accurate runoff, which plays a major role in integrated flood management. If this model is combined with the techniques of rainfall forecasting, it will contribute to the real-time flood forecasting and warning in the future.

• Korean Journal of Social Welfare Studies
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• v.49 no.1
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• pp.51-83
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• 2018

This study examines whether the widening gap between income groups is worsening in the distribution of time use, similar to the worsening of income distribution after the IMF. To do this, we conducted multilevel analysis (HLM) on six countries including France, the Netherlands, Spain, the United Kingdom, the United States and Korea. The results of the analysis are as follows. First, in all countries, low income groups have a longer paid working time and shorter leisure time. Second, the low income groups in Korea have the longest paid work time and the shortest leisure time, the lowest level of work-leisure balance, and this aspect has not recovered since the IMF. Third, as the result of multilevel analysis, the lower the household income, the more time paid labor increased and the work-leisure balance decreased. Fourth, while average annual working hours increase paid working time, the expansion of family policy expenditure, redistribution policy and income maintenance policy has reduced it. Fifth, the annual average working hours decreased the work-leisure balance, but the family policy expenditure, the redistribution policy and the income guarantee policy increased the work-leisure balance. The significance of this study is that after the IMF, not only the income distribution but also the inequality among the income class in time use has deepened. Based on the results of the research this study suggests the reinforcement of labor time regulation, the activation of parental leave system, the realization of the income replacement rate, the expansion of the policy related to income redistribution, and the complementary development of the income guarantee and the time guarantee policy as the policy intervention strategy that restructures time.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.47-51
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• 2008

무선 센서 네트워크 환경에서의 구성요소간의 상호 인증은 중요하다. $\mu$-TESLA에서의 브로드캐스트 인증은 인증시간의 지연이 발생한다. 지연의 발생은 현재 받은 메시지의 인증이 메시지를 받은 즉시 이루어지지 않고 다음 메시지를 받았을 때 이전의 메시지에 대한 인증이 이루어지기 때문이다. 이는 실시간 처리를 필요로 하는 통신에는 적합하지 않다. 또한 대칭키를 기반으로 인증하는 방법에서는 인증시간의 지연이 발생하지 않지만 인증을 위한 키가 노출되었을 때, 키를 재생성, 분배해야하는 문제가 있다. 본 논문에서 제안하는 인증방안은 식별자와 해쉬 함수를 이용하여 인증시간의 지연이 없는 실시간 인증과 인증에 사용하는 식별자가 노출되었더라도 키의 재생성 및 분배없이 인증을 달성하는 방법을 제시한다.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.36-50
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• 2015

The purpose of this study is to assign emission source profiles of volatile organic compounds (VOCs) and particulate matters (PMs) for chemical speciation, and to correct the temporal allocation factor and the chemical speciation of source profiles according to the source classification code within the sparse matrix operator kernel emission system (SMOKE) in the Seoul metropolitan area. The chemical speciation from the source profiles of VOCs such as gasoline, diesel vapor, coating, dry cleaning and LPG include 12 and 34 species for the carbon bond IV (CBIV) chemical mechanism and the statewide air pollution research center 99 (SAPRC99) chemical mechanism, respectively. Also, the chemical speciation of PM2.5 such as soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal fired, power plant, biomass burning and marine was allocated to 5 species of fine PM, organic carbon, elementary carbon, $NO_3{^-}$, and $SO_4{^2-}$. In addition, temporal profiles for point and line sources were obtained by using the stack telemetry system (TMS) and hourly traffic flows in the Seoul metropolitan area for 2007. In particular, the temporal allocation factor for the ozone modeling at point sources was estimated based on $NO_X$ emission inventories of the stack TMS data.

• KSBB Journal
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• v.16 no.5
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• pp.442-445
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• 2001

Catechin compounds as anticancer and antioxidant were target materials from Korean Green Tea in this work. The methodologies of solvent extraction and partition were utilized to recover catechin compounds from green tea and the optimal experimental conditions were found by comparing the degree of recovery as slovent. extraction times and operating temperatures. The extract was partitioned with chloroform, which was best fit to remove caffeine after the extraction of green tea with 80$^{\circ}C$ water for 40 min. Further, the resulting extract was partitioned in ethyl acetate layer to purify the catechin compounds of EGC, EC EGCG and ECG. This experimental result could be extended to preparative HPLC to obtain EGCG on a commercial scale.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.48-57
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• 2000

The need for high bandwidth, very dynamic secure internet multicast communications is increasingly evident in a wide variety of commercial, government, and internet communities. One of the most recently researches is mainly about the group key distribution schemes[1,3,4,5]. In this paper, we survey related group key distribution schemes and propose a new scalable distributed group key distribution scheme which is one of the most important parts in internet multicast environment. Then, we add this scheme to the existing multicast applications and analysis the test results. The proposed SDGD minimizes the times required to distribute and redistribute keys for joining and leaving the multicast group.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.148-158
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• 2009

Firstly the problems of existing foreign code concerning wheel load distribution factor for skew box girder bridges have been examined, and the main parameters which have effects on wheel load distribution factors are evaluated in this study. Further finite element analyses on various skew steel box girder bridges are carried out. Based on the analysis results, formulas to determine wheel load distribution factors are proposed using multiple regression analysis. It is found when using the proposed formulas in this study weak points of existing specifications could be improved and also time spent at structural analysis should be saved a lot, so that the validity and practicality could be verified.

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.128-129
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• 2002