• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.63-76
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• 2008

The goals of this study are to develop travel time functions based on intersection delay and to analyze the applicability of the functions to traffic assignment models. The study begins with the premise that the existing assignment models can not effectively account for intersection delay time. In pursuing the goals, this study gives particular attention to dividing the link travel time into link moving time and stopped time at node, making the models based on such variables as the travel speed, volume, geometry, and signal data of signalized intersections in Cheongju, and analyzing the applicability of these models to traffic assignment. There are several major findings. First, the study presents the revised percentage of lanes (considering type of intersection) instead of g/C for calculating intersection delay, which is analyzed to be significant in the paired t-test. Second, the assigned results of applying these models to the Cheongju network in EMME/2 are compared with the data observed from a test car survey in Cheongju. The analyses show that the BPR models do not consider the intersection delay, but the modified uniform delay model and modified Webster model are comparatively well fitted to the observed data. Finally, the assigned results of applying these models are statistically compared with the test car survey data in assigned volume, travel time, and average speed. The results show that the estimates from the divided travel time model are better fitted to observed data than those from the BPR model.

• Proceedings of the Korea Association of Information Systems Conference
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• 1996.11a
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• pp.171-183
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• 1996

• Korea Information Processing Society Review
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• v.2 no.3
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• pp.23-32
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• 1995

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.151-151
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• 1999

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1996.10a
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• pp.171-183
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• 1996

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.10a
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• pp.281-292
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• 1994

• Proceedings of the Korea Association of Information Systems Conference
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• 2000.11a
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• pp.11.1-16
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• 2000

• Journal of the Korean Society of Industry Convergence
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• v.4 no.1
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• pp.27-34
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• 2001

Refining of powder particles and their dissolution into the Al matrix during mechanical alloying(MA) were investigated by using X-ray diffraction(XRD) transmission electron microscopy (TEM) functions of alloy composition, milling time and ball to powder ratio(BPR). It is found that Ti particles less than 20nm are observed in a dark field image of mechanically alloyed Al-10wt%Ti whose XHD pattern exhibits no Ti peak. The observed change of lattice constant of AI indicates that about 1 wt%Ti can he solved in Al after MA for a long time, independent of alloy composition, milling time and BPR, suggesting that most of Ti particles arc retained in the Al matrix. It is concluded that the disappearance of XRD peaks in mechanically alloyed Al-10wt%Ti is not simply attributable to the dissolution of Ti into Al, but associated mainly with extreme refining and/or heavy straining of Ti Particles.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.477-486
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• 1999

1990년대 중반에 한국기업에 도입된 ERP 시스템은 현재 많은 기업에서 현업에 활용되고 있거나 혹은 도입 의사결정을 하고 있는 상태이다. 특히 IMF 구제금융 이후 ERP 시스템은 단순한 효율성제고의 차원을 넘어 기업의 생존전략 및 경쟁력제고전략의 수단으로 활용되고 있는 추세이다. ERP시스템이 이렇게 전략적 차원의 수단으로 활용되고 있는 가장 중요한 요인은 ERP시스템이 기존의 수주개발시스템과 단위패키지시스템과 비교할 때, 시스템 통합에 기반한 양질의 비즈니스 프로세스를 제공하고 있다는 점과, 투자비용이 비교적 적고 개발기간이 비교적 짧다는 점을 들 수 있다. ERP의 발전과정은 기능별 시스템의 통합과정으로 이해할 수 있고, 또한 ERP시스템과 기존의 수주개발시스템 또는 단위패키지시스템의 가장 뚜렷한 차이가 바로 통합이라는 사실을 상기할 때, ERP시스템의 최대 가치는 통합에 있다. 한편 거대한 기업정보시스템의 통합을 가능하게 한 것은 바로 고급정보기술이다.(중략)

• Journal of Information Technology Applications and Management
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• v.15 no.4
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• pp.123-136
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• 2008

This study tried to find out the effect of change management on the ERP performance in small and medium size companies. Communication, BPR management, education and training were selected as independent variables which might bring an effect on ERP performances which were classified as quality and quantity one. Structure equation model was built and analyzed with AMOS 5.0 version from data gathered through 127 companies which already implemented ERP systems. The result of this study shows that all the three independent variables give positive impacts on two dependent variables, which means change management is critical when small and medium size companies want to implement ERP systems.