• 한국대기환경학회지
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• 제22권2호
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• pp.235-247
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• 2006

Aerosol indirect radiative forcing of climate change is considered the most uncertain forcing of climate change over the industrial period, despite numerous studies demonstrating such modification of cloud properties and several studies quantifying resulting changes in shortwave radiative fluxes. Detection of this effect is made difficult by the large inherent variability in cloud liquid water path (LWP): the dominant controlling influence of LWP on optical depth and albedo masks any aerosol influences. Here we have used ground-based remote sensing of cloud optical depth (${\tau}_c$) by narrowband radiometry and LWP by microwave radiometry to determine the dependence of optical depth on LWP, thereby permitting examination of aerosol influence. The method is limited to complete overcast conditions with liquid-phase single layer clouds, as determined mainly by millimeter wave cloud radar. The results demonstrate substantial (factor of 2) day-to-day variation in cloud drop effective radius at the ARM Southern Great Plains site that is weakly associated with variation in aerosol loading as characterized by light-scattering coefficient at the surface. The substantial scatter suggests the importance of meteorological influences on cloud drop size as well, which should be analyzed in the further intensive studies. Meanwhile, it is notable that the decrease in cloud drop effective radius results in marked increase in cloud albedo.

• 한국철도학회논문집
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• 제10권4호
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• pp.451-456
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• 2007

Organizational abilities which assure human resource of excellent quality in enterprise and organization, manages human resource effectively and systematically will be depended on the performance and successful or not of enterprise. The organization which readies to accept changes will survive, the organization makes full use of changes to opportunity and strategy will be a winner. Now when the environment of enterprise is uncertain and environment of management changes, organization should manage HRM in strategic point of view to maintain persistent competition superiority. We investigated how outsourcing affected on organizational performance perception according to inducting BSC from the employees of metro. As a result of the investigation, outsourcing is perceived importantly in study, growth, internal process point of view, but didn't perceived in finance and customer. We guessed that outsourcing would be perceived importantly in financial point of view as a cost reduction. In 5 years from the beginning of metro, it seemed to be perceived importantly, as organizations grow older, perceptions of outsourcing are perceived low because of stabilization of organization and labor's resistance. It is why that the more outsourcing is performed, the more reduction of organization and decrease of employees is expected as much as cost reduction.

• 한국중재학회지:중재연구
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• 제16권3호
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• pp.191-216
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• 2006

It has been talked about the responsibility of the South-North Korean e-market place(e-MP) collaboration project every you since 2003. However, the feasibility as the business has not been dealt with in detail due to the uncertain environment as well as the complicated procedures of the project. The research focuses on the workable mechanism of the South-North Korean E-Market Place collaboration project. The feasibility of the project results from the newly installed fiber telecommunication network as well as the 1 billion dollars of the trading volume between South and North Korea. The research analyzes on the capabilities as well as willingness of the South and North Korea for the e-MP, and concludes with two paradigms of the future tasks. First, the unified but step-wise structure should be made to promote the project by the political committee (South and North Korea EC Committee) and the economical administration body (South and North Korea EC Corporation). Second, the market-oriented resolution system such as South and North Korea Arbitration Body should be involved to create legal environment. Above all, the discussion should be on the main body of e-MP settlement to abolish the psychological as well as practical barriers to enter the South-North Korean electronic commerce.

• 한국건설관리학회논문집
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• 제5권5호
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• pp.151-162
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• 2004

Current methods for construction site modeling employ large, expensive laser range scanners that produce dense range point clouds of a scene from different perspectives. Days of skilled interpretation and of automatic segmentation may be required to convert the clouds to a finished CAD model. The dynamic nature of the construction environment requires that a real-time local area modeling system be capable of handling a rapidly changing and uncertain work environment. However, in practice, large, simple, and reasonably accurate embodying volumes are adequate feedback to an operator who, for instance, is attempting to place materials in the midst of obstacles with an occluded view. For real-time obstacle avoidance and automated equipment control functions, such volumes also facilitate computational tractability. In this research, a human operator's ability to quickly evaluate and associate objects in a scene is exploited. The operator directs a laser range finder mounted on a pan and tilt unit to collect range points on objects throughout the workspace. These groups of points form sparse range point clouds. These sparse clouds are then used to create geometric primitives for visualization and modeling purposes. Experimental results indicate that these models can be created rapidly and with sufficient accuracy for automated obstacle avoidance and equipment control functions.

• 한국국방경영분석학회지
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• 제16권1호
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• pp.18-34
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• 1990

In light of the recent developments of transitory nature, it is likely that national defense decision-making will be more difficult to make for years to come. In other words, sudden changes in security environment would call into question the basic assumptions on which we have built our national defense planning and increase the number of the uncertain factors in the decision-making process; the subdivision and ramification of national defense management would increase the factors for decision-making and complicate even further the mutual interactions among these factors; the accelerated pace of sophistication and diversification of weapon systems and military technology would increase the risk of failure and system costs geometrically; and the reduced level of acceptance among the people on the sanctification of national defense in proportion to the rapid progress toward a more democratic and industrial society would engender an increased criticism or checking role by the National Assembly or by the mass media. As the changes in national defense environment and conditions create an innumerable number of new tasks, this paper intends to suggest a few core policy measures to improve the quality of national defense decision-making. More specifically, it proposes to 1) eradicate entirely the bureaucratic behavior and tendencies; 2) utilize actively the brain staff for quality assurance of decision-making; 3) and introduce and apply as a whole set, a total system, or an incorporated pack age the PPBEES(Planning-Programming-Budgeting-Executing-Evaluating-System)/LCMM (Life-Cycle Management Model for System Acquision), the OR/SA(Operations Research/Systems Analysis), and DMIS (Defense Management Information System).

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1290-1303
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• 2005

In this research, a remote control system has been developed and implemented, which combines autonomous obstacle avoidance in real-time with force-reflective tele-operation. A tele-operated mobile robot is controlled by a local two-degrees-of-freedom force-reflective joystick that a human operator holds while he is monitoring the screen. In the system, the force-reflective joystick transforms the relation between a mobile robot and the environment to the operator as a virtual force which is generated in the form of a new collision vector and reflected to the operator. This reflected force makes the tele-operation of a mobile robot safe from collision in an uncertain and obstacle-cluttered remote environment. A mobile robot controlled by a local operator usually takes pictures of remote environments and sends the images back to the operator over the Internet. Because of limitations of communication bandwidth and the narrow view-angles of the camera, the operator cannot observe shadow regions and curved spaces frequently. To overcome this problem, a new form of virtual force is generated along the collision vector according to both distance and approaching velocity between an obstacle and the mobile robot, which is obtained from ultrasonic sensors. This virtual force is transferred back to the two-degrees-of-freedom master joystick over the Internet to enable a human operator to feel the geometrical relation between the mobile robot and the obstacle. It is demonstrated by experiments that this haptic reflection improves the performance of a tele-operated mobile robot significantly.

• 전자공학회논문지B
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• 제33B권11호
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• pp.1-10
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• 1996

In this paper, we suggest a new identification method based on the takagi-sugeno fuzzy model which prepresents an envrionmental stiffness and propose a method to decide PD gains of the PD controller. It is difficult to perform a compliance task due to characteristics of robot itself and uncertain work envronment. Therefore, in this paper, we identify the fuzzy rule by dividing the relationship of input-output data into several piecewise-linear equations using the hough transform which is the one this fuzzy model, we propose a method to design the pD gain. We show the validity of this method by the experiment of tracking the surface of the paper box as an example of variable environment using robot manipulator and force sensing system. As a performance index, we use the settling time, and perform an analysis between conventional PD contorllers and this controller.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2005년도 추계학술대회 학술발표 논문집 제15권 제2호
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• pp.305-308
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• 2005

시각 센서를 이용한 환경 및 상황 인식은 로봇의 자동화된 행동을 위해서 매우 중요하다. 실제 환경에서 사람은 주위를 인식할 때 여러 단계의 인식과정을 거친다. 효율적이고 정확한 환경 인식을 위해서는 지능형 로봇의 인식 또한 사람의 인식과정과 같이 다단계로 이루어져야 한다. 또한 실제 환경은 유동적이며 많은 불확실성을 가지고 있으므로 불확실한 상황에 강인한 인식 방법이 필요하다. 이러한 불확실성을 내포한 환경 및 상황 인식에는 베이지안 네트워크를 이용한 인식이 강인하나 복잡한 환경을 하나의 베이지안 네트워크로 인식하는 것은 어렵다. 이 논문에서는 복잡하고 불확실한 환경 인식을 위한 여러 베이지안 네트워크를 사람의 인식과 같은 다단계의 인식 과정으로 구성된 행동 네트워크 기반으로 결합하는 앙상블 기법을 제안한다. 불확실한 상황을 적용한 환경 실험과 로봇 시뮬레이터를 이용한 로봇 실험으로 베이지안 네트워크 앙상블 기법이 환경 인식에 효과적인 것을 확인할 수 있었다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권1호
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• pp.19-30
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• 2013

Recently, the constrained index tracking problem, in which the task of trading a set of stocks is performed so as to closely follow an index value under some constraints, has often been considered as an important application domain for control theory. Because this problem can be conveniently viewed and formulated as an optimal decision-making problem in a highly uncertain and stochastic environment, approaches based on stochastic optimal control methods are particularly pertinent. Since stochastic optimal control problems cannot be solved exactly except in very simple cases, approximations are required in most practical problems to obtain good suboptimal policies. In this paper, we present a procedure for finding a suboptimal solution to the constrained index tracking problem based on approximate dynamic programming. Illustrative simulation results show that this procedure works well when applied to a set of real financial market data.

• 한국경영과학회지
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• 제13권2호
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• pp.163-163
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• 1988

This research shows that fuzzy set theory can be useful in modeling and solving flow shop scheduling problems with uncertain processing times and illustrates a method for solving job sequencing problem which the opinions of experts disagree in each processing time. In this study, FCDS (Fuzzified Campbell-Dudek-Smith) algorithm and FNEH (Fuzzified Nawaz-Enscope-Ham) algorithm are proposed to improve the fuzzified Branch & Bound algorithm that requires long run-time and computational complexities to find the optimal sequence. These proposed algorithms are also designed to treat opinions of experts. In this paper, Fuzzy processing times are expressed as triangular fuzzy numbers and comparison method use Lee-Li method and ranking method based on the dominance property. On the basis of the proposed method, an example is presented.