• Journal of KIISE:Computer Systems and Theory
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• v.26 no.2
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• pp.189-197
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• 1999

배리어 프리미티브는 병렬 프로그램을 수행할 때 계산에 참여한 프로세서들 사이에 동기화를 위하여 사용된다. 그러나 배리어에 일찍 도착한 프로세서들은 나머지 프로세서들이 배리어에 도착할 때 까지 배리어에서 기다리게 되므로 프로세서들의 활용율이 떨어진다. 본 논문에서는 배리어 대기시간의 원인들을 찾기 위하여 병렬 프로그램들을 다양한 그레인 크기들로 수행하였다. 모든 프로세서들이 동일한 개수의 그레인들을 수행함에도 불구하고 그레인 크기에 따라 변화되는 명령어들과 캐쉬 실패들은 배리어 대기 시간에 영향을 미치고 있음을 시험한다. 또한 배리어에서의 맹목적 대기시간을 감소시키기 위하여 동기화 기능을 두 단계로 나누어 수행하는 두 단계 배리어를 제안한다. 모의 실험 결과는 병렬 프로그램의 그레인 크기는 배리어 대기시간에 영향을 미치고 있음을 보여주며 또한 제안된 두단계 배리어가 기존의 배리어 프리미티브보다 배리어에서의 대기시간을 줄여주고 있음을 보여준다.

• Journal of Venture Innovation
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• v.6 no.4
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• pp.1-21
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• 2023

This study is related to the performance of open innovation collaboration between startups and large corporations and financial institutions. In the life cycle of a typical company, the growth of a startup is difficult to predict. Startups that possess innovative technology but have only recently been established seek to verify their technology and capabilities by participating in open innovation with large corporations and financial institutions, and further strive to lay the foundation for corporate growth. However, if you approach it only as a theoretical coexistence plan, it will be viewed as a vague attempt from the startup's perspective. The purpose of this study is to differentiately verify the benefits of open innovation by analyzing the difference in sales growth of startups for the purpose of sales performance based on the open innovation participation of large companies and small and medium-sized companies(startups). In verifying this, the analysis was based on the sales results of the actual open innovation collaboration B2C model, and the difference was confirmed by comparing before and after collaboration. Here, the differentiation of the study was added by reflecting the corporate growth stage theory, a growth theory. When the corporate growth stage theory was excluded, it was confirmed that sales growth due to open innovation of startups was applied from the third month, and sales growth depending on participation was confirmed to be significant. On the other hand, when the corporate growth stage theory was applied, sales growth was not significant, but the difference in growth could be confirmed from the fourth month, and it was also confirmed in sales growth depending on participation. As a result, this study objectively confirms the effects that can be gained when startups participate in Open-innovation, and it is expected that Open-innovation led by large corporations, financial institutions, and government agencies will develop into a high-quality program environment.

• Journal of Technology Innovation
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• v.26 no.3
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• pp.98-128
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• 2018

This study aimed to investigate the performance on technology collaboration of small and medium enterprises in Korea from the views of resource-based theory. Considering that supplementing the technical resources is stressed in a motivation of technology collaboration from the corresponding theoretical perspective, a group of corporations to be analyzed was classified into three categories such as high, medium and low technologies depending on the technology level. Moreover, technology collaboration partners were also classified into large corporation, small and medium enterprises, university and institution based on that both tangible and intangible assets that belong to a corporation semi-permanently, and the revolutionary performance was analyzed by each relationship of collaboration between parties. The study results revealed that an influence on the performance of technology collaboration varies by technology level of the small and medium enterprises in Korea and their collaboration partners. In particular, the small and medium enterprises of high-tech industry in Korea were confirmed to accomplish relatively less benefits obtaining through technology collaboration compared to the corporations with low technical skills.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.33-46
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• 2022

This paper, in order to minimize the ground waiting time of an Air tanker, the queuing theory, that is, a queue that calculates the waiting time under single-server and multi-server situations, was used in the study. Since the national budget and resources are limited, the unlimited increase of the logistics support service team is limited. Therefore, the number of logistic support service teams that can adaptively control the ground waiting time according to the wartime preparation stage or war environment was calculated. The results of this study provide a stipulated standard for calculating the optimal number of air tanker logistic support service teams of the Air Force, providing a basis for the logistical commander to assign logistic support service teams to each stage from peacetime to wartime.

• 전기의세계
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• v.44 no.9
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• pp.9-14
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• 1995

최근 건물이 고층화, 대형화로 진전되면서 엘리베이터는 건물내의 주요한 교통 수단으로 복잡한 교통 수요를 효율적으로 해소하기 위한 합리적 운행에 관련되는 제어기술이 급진적으로 발전되고 있다. 또한 고도 정보화 시대에 대응하기 위하여 정보통신 설비를 효율적으로 운용하고 있는 인텔리젼트 빌딩에 있어 엘리베이터 시스템은 다종, 다양한 기능을 가지도록 needs가 증가되고 있는 실정이다. 특히 엘리베이터 시스템의 요구 needs 중에 승객에게 쾌적한 기능과 균등화를 실현시켜 운행의 효율화를 극대화 하고 대기시간의 단축과 승객의 편이성을 도모하기 위한 엘리베이터 군관리 제어 시스템에 있어 최근 응용되고 있는 Fuzzy이론을 이용한 군관리 제어에 관하여 기초적인 Fuzzy이론 개념을 해설하고자 한다.

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.334-344
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• 2020

The adsorption of various atmospheric harmful gases (COx, NOx, SOx) on graphene-like Germanene 2D sheet was theoretically investigated using density functional theory(DFT) method. The structures were fully optimized at the B3LYP/cc-pvDZ and CAM-B3LYP/cc-pvDZ levels of theory and confirmed to be a local minimum by the calculation of the harmonic vibrational frequencies. The adsorptions of gases on the Germanene sheet were predicted to be a physisorption process for CO, CO2, NO, and SO2 gases but to be a chemisorption process for NO2, SO, and SO2 gases.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.250.2-250.2
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• 2015

결정질 태양전지의 변환효율은 이미 이론적 한계에 가까워져, 최근 산업에서는 이 대신 제조공정 단가를 낮추려는 연구가 진행되고 있다. 본 연구에서는 태양전지 도핑공정에 대기압 DBD 플라즈마를 응용하여 저렴하게 태양전지를 제작할 수 있는 방법을 모색한다. 대기압 DBD 플라즈마를 발생시키기 위해 DC-AC 인버터 구조의 전원을 사용하여 수십 kHz의 주파수, 수 kV의 전압을 인가하여 $5cm{\times}1cm$ 직사각형 모양의 아노다이징된 알루미늄 전극을 사용하였다. 전극과 Ground 사이에 Argon 가스를 주입하여 플라즈마를 발생시켰으며, 출력전류는 수십 mA의 전류가 측정되었다. $3cm{\times}3cm$의 P-type wafer에 스핀코팅 방식으로 H3PO4를 도포한 후, Wafer 표면에 플라즈마를 조사하여 대기압 DBD 플라즈마를 이용한 태양전지 도핑 가능성을 확인하였다. 플라즈마 출력 전류와 플라즈마 조사시간을 변수로 도핑된 Wafer의 특성을 확인하였다. 도핑 프로파일은 SIMS (Secondary Ion Mass Spectrometry)를 통해 측정하였으며, 전기적인 특성은 4 point probe로 면저항을 측정하였다. 대기압 DBD 플라즈마를 이용해 도핑된 wafer에 전극을 형성하여, 같은 도펀트를 사용하여 Furnace로 열 확산법을 이용해 도핑 공정을 진행한 wafer와 변환효율(Conversion efficiency)을 측정하여, 대기압 플라즈마를 이용한 도핑 가능성을 확인하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 1987.07a
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• pp.31-42
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• 1987

본 연구는 유역의 지형인자를 대기행렬이론(Queueing theory)에 적용하여 하천유역의 강우-유출 관계를 해석하고, 미 계측 유역이나 자료가 결핍된 유역에 적용할 수 있는 GIUH(Geomorphologic Instantaneous Unit Hydrograph)모델의 매개변수를 결정하는데 그 목적을 두었다. GIUH모델의 개념은 유역 시스템내의 강우의 지속기간동안 유역의 출구에서 가능한 많은 경로를 추적 할 수 있을것이라는 강우 대기행렬이론의 원리에 기초를 두었으며, 적용기법은 분할법(Sub-area method)과 평균치법(Mean-value method)을 적용하였다. GIUH모델의 적용성을 증명하기 위해서, 낙동강 위천유역(유역면적 472.53km)에 적용하였으며, 분할법과 평균치법은 유역의 분할을 위해서 채택하였다. 계산된 직접 유출 수문곡선과 관측 직접 유출 수문곡선을 비교한 결과는 첨두 유출량, 도달시간, 효률계수가 매우 근접한 결과를 나타내고 있었다. 따라서, GIUH모델은 미 계측 유역이나 자료가 결핍된 유역의 유출량 산정에 광범위하게 적용할 수 있음을 알 수 있었다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.193-206
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• 2002

A signal optimization model is proposed by applying the Cell-Transmission Model(CTM) as an embedded traffic flow model to estimate a system-optimal signal timing plan in a transportation network composed of signalized intersections. Beyond the existing signal-optimization models, the CTM provides appropriate theoretical and practical backgrounds to simulate oversaturation phenomena such as shockwave, queue length, and spillback. The model is formulated on the Mixed-Integer Programming(MIP) theory. The proposed model implies a system-optimal in a sense that traffic demand and signal system cooperate to minimize the traffic network cost: the demand departing from origins through route choice behavior until arriving at destinations and the signal system by calculating optimal signal timings considering the movement of these demand. The potential of model's practical application is demonstrated through a comparison study of two signal control strategies: optimal and fixed signal controls.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.628-633
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• 2008

Tall building construction has been increasing due to the need to maximize land usage. It causes the increase of vertical transportation for workers and materials, which significantly affects the productivity and lifting planning, therefore, has to be made carefully based on the characteristics of the field. However, the existing method to calculate the number of lift is too simple to consider complex and various characteristics in tall building construction. Accordingly, we developed the model for selecting the best system of vertical transportation by using Queueing theory. To find out the situation of the queue of resources such as material and workers, a simulation program will be applied.