• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.139-143
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• 1991

GRIN-SCH quantum well structured Laser Diode were fabricated using MOCVD and operated as CW at room temperature. The threshold current density of the LD with 670${\mu}{\textrm}{m}$ cavity length was 530 A/$\textrm{cm}^2$. For the ridge waveguide type index guiding structured LD with 6${\mu}{\textrm}{m}$ stripe width and 240${\mu}{\textrm}{m}$ cavity length, the threshold current was 50㎃. The maximum differential quantum efficiency was 0.95W/A when the optical output was 60mW. The lasing wavelength of QW LD was 865nm. In the L-I measurement. TE mode was superior to TM mode. From the near field pattern, single lateral mode operation was observed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.699-704
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• 2004

As being inconvenient to apply reinforced concrete structure to high-rise buildings, it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But, the required performances of a light-weight wall are not evaluated systematically. As a field survey result, partition walls of house-to-house were not showed their respected performances, so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially, occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings. As a result, a new drywall system was presented and the performance was verified with field test.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1151-1156
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• 2003

To obtain both of the fast and complete data entry and the acquisition of reusable data in a Computer-based Patient Record system (CPR), we are building the ontology that is used by the entry supporting agents. Our application domain is Traditional Chinese Medicine. As the tool for the implementation, we used protege 2000 which is ontology building tool and provides frame knowledge representation language. In this paper, the construction methodology of our ontology is reported.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.167-170
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• 2000

Recently the sub-micron structured substrates of 0.74 ${mu}ell$ track pitch and 800 $\AA$groove depth are required for DVD-RAM and the track pitch is expected to be narrower as the need for the information storage density is getting higher. For the accurate replication of the land-groove structure in the stamper to the plastic substrates it is important to control the injection -compression molding process such that the integrity of the replication for the land-groove structure is maximized. in the present study polycarbonate substrates were fabricated by injection comression molding and the land-groove structure regarded as one of mold temperature and the compression pressure on the integrity of the replication were examined experimentally. An efficient design methodology using the response surface method (RSM) the central composite design(CCD) technique and the analysis-of-variance (ANOVA) was developed to obtain the optimum processing conditions which maximize the integrity of the replication with a limited number of experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.338-342
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• 1997

본 논문에서는 상태와 입력에 시간지연과 구조화된 불확실성이 있는 시스템을 위한 강인 H/sub .inf./ 제어기를 제안한다. 제안된 제안기는 시간지연의 크기에 관계없이 항상 불확실한 시스템을 안정화시키고, 또한 제한된 크기의 어떤 구조화된 불확실성에 대해서도 항상 폐루프 전달함수의 H/sub .inf./ 노옴의 크기를 주어진 레벨 이하로 줄인다. 제어기는 볼록 최적화 알고리즘을 이용한 LMI 문제를 풀어서 구한다.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.2
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• pp.116-120
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• 2000

This paper presents a method to assign robustly the closed loop system's poles in a specified disk by a state feedback for a linear time invariant system with structured or unstructured uncertainties. THe proposed robust design procedure includes two steps. Firstly, the perturbed closed loop matrix $A_{cl p}$ = $A_{cl}$ + Δ$A_{cl}$ is rearranged such that it is a function of the nominal closed loop matrix $A_{cl}$. Hence, we can control the positions of the perturbed closed loop poles by choosing $A_{cl}$ appropriately. Secondly, the feedback control law F that assigns the closed loop poles of the perturbed system in a specified disk is determined from the equation $A_{cl}$ = A + BF. A procedure for finding F is proposed based on partitioning every matrix of the equation $A_{cl}$ = A + BF in the horizontal direction.

• International Journal of Control, Automation, and Systems
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• v.5 no.2
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• pp.184-191
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• 2007

Autonomous navigation of mobile robot requires a ranging system for measurement of distance to environmental objects. It is obvious that the wider and the faster distance measurement gives a mobile robot more freedom in trajectory planning and control. The active omni-directional ranging system proposed in this paper is capable of obtaining the distance for all 3600 directions in real-time because of the omni-directional mirror and the structured light. Distance computation including the sensitivity analysis and the experiments on the omni-directional ranging are presented to verify the effectiveness of the proposed system.

• Architectural research
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• v.1 no.1
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• pp.23-30
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• 1999

This research investigates a system for house design automation. The system is based on an object-oriented building data model, aiming to support the house design process conducted by non-expert users. Its object model, with simple yet powerful user interfaces, enables a CAD system to handle a complicated building system with much ease. Hence, the model dramatically simplifies the design process beyond just the automatic document generation. In this paper, we discuss the aspects of the building data model, introduce critical concepts such as grid objects and structured floor plan, and present a prototype system called GPLAN. The system is implemented in the framework of our building data model, and it provides a host of intelligent features that have been proved useful for house design automation.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.373-385
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• 2006

To solve a class of nonlinear parameter estimation problems, a method combining the regularized structured nonlinear total least norm (RSNTLN) method and parameter separation scheme is suggested. The method guarantees the convergence of parameters and has an advantages in reducing the residual norm over the use of RSNTLN only. Numerical experiments for two models appeared in signal processing show that the suggested method is more effective in obtaining solution and parameter with minimum residual norm.

• Asia pacific journal of information systems
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• v.9 no.2
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• pp.1-17
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• 1999

A feedback echo is a structured restatement of the user's query and informs the user what the system intends to do for the query. This provides backtracking of the user's query so that the user knows how the system has interpreted the query. This study scrutinizes whether the feedback echo, as currently available in the INTELLECT commercial system, can improve the performance of a casual user using a restricted natural language database interface. This study concludes that the particular type of feedback echo available in this commercial system was not effective in terms of overall performance for casual users. It is worth mentioning, however, that the feedback echo was effective for the specific type of error: using wrong conditions for data retrieval.