• 산업공학
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• 제18권4호
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• pp.431-443
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• 2005

This paper describes a web-based system called DESIGNER for the analysis and design for automated material handling equipment(MHE) applications in manufacturing. DESIGNER models the processes for system integration, economic analysis, performance analysis, and automated storage/retrieval system(AS/RS) design. Based on the information specified by users, the various analysis modules are invoked to meet the needs of the material handling applications. The results of the analyses provide system users with useful data for material handling system design and decision on investment in automated MHE. Example problems are also presented to demonstrate the use of the system.

• 한국기계가공학회지
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• 제9권3호
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• pp.28-34
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• 2010

The suggested coupled system was analyzed using FRF and mode analysis. The eigen-mode of FRF analysis is consistent with that of conventional FFT in spectrum. Also, three numerical responses of second order system, which are coupled, was obtained using the Runge-Kutta Gill method. The displacement, velocity and acceleration response were calculated for the numerical analysis of coupled system and the displacement response was used for the calculation of FRF of this system. Using the mixed response of 1st and 2nd mode in example, the FRF was analysed for the analysis of mixed mode coupled system. Also, its mode shape was acquired by solving the eigen problem of coupled system.

• Journal of Communications and Networks
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• 제8권2호
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• pp.220-227
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• 2006

In this paper, we present a novel approach to analyze the throughput of direct-sequence spread spectrum multiple access (DS/SSMA) unslotted ALOHA system. In the unslotted system, the departure rate of interfering transmissions is proportional to the number of current interferers that can be regarded as the system state. In order to model this state-dependency, we introduce a two-dimensional state transition model that describes the state transition of the system. This model provides a more rigorous analysis tool for the DS/SSMA unslotted ALOHA systems with both fixed and variable packet lengths. Numerical results reveal that this analysis yields an accurate system performance that coincides with the simulation results. Throughout the analysis we have discovered that the state-dependency of the departure rate causes interference averaging effect in the unslotted system and that this effect yields a higher throughput for the unslotted system than for the slotted system when supported by a strong channel coding.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.344-349
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• 2005

In conventional small signal stability analysis, the system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of the state matrix. However, when a system contains switching elements such as FACTS equipments, it becomes a non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is performed by means of eigenvalue analysis of the system's periodic transition matrix based on the discrete system analysis method. In this paper, the RCF (Resistive Companion Form) method is used to analyze the small signal stability of a non-continuous system including switching elements. Applying the RCF method to the differential and integral equations of the power system, generator, controllers and FACTS equipments including switching devices should be modeled in the form of state transition equations. From this state transition matrix, eigenvalues that are mapped into unit circles can be computed precisely.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.342-344
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• 2004

In conventional small signal stability analysis, system is assumed to be invariant and the state space equations are used to calculate the eigenvalues of state matrix. However, when a system contains switching elements such as FACTS devices, it becomes non-continuous system. In this case, a mathematically rigorous approach to system small signal stability analysis is by means of eigenvalue analysis of the system periodic transition matrix based on discrete system analysis method. In this research, RCF(Resistive Companion Form) method is used to analyse small signal stability of a non-continuous system including switching elements'. Applying the RCF method to the differential and integral equations of power system, generator, controllers and FACTS devices including switching elements should be modeled in the form of state transition matrix. From this state transition matrix eigenvalues which are mapped to unit circle can be calculated.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.215-222
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• 2002

It has been well acknowledged that intake system plays great role in the performance of reciprocating engine. Well-designed intake system is expected to not only increase engine efficiency but also decrease engine emission, which is one of the most urgent issues in the automotive society. Thorough understanding of the flow in intake system helps great to design adequate intake system. Even though both experimental and numerical methods are used to study intake flow, numerical analysis is more widely used due to its merits in time and economy. Intake system of In-line 6-Cylinder CNG engine was chosen for the analysis ICEM CFD HEXA was used to create 3-D structured grid and FIRE code was used for the flow analysis in the intake system. Due to the complexity of the geometry standard ${\kappa}-{\varepsilon}$ turbulence model was applied. Numerical analysis was performed for various inlet and outlet boundary conditions under both steady and transient flow. Inlet mass flow rate and outlet pressure variation were changing parameters with respect to engine speed. Flow parameters, such as velocity, pressure and flow distribution, were evaluated to provide adequate data of this intake system.

• 한국태양에너지학회 논문집
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• 제23권4호
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• pp.11-20
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• 2003

This study aims to develop the program for active solar heating system design & analysis. The program, named ASOLis, is consisted of three user's interface like as system input/output, library, and utilities and used TRNSYS as a calculation engine for the system analysis. ASOLis simplifies user's input data through the database and can design 37 different types of solar systems. Solar system is configurated by two separated parts "solar thermal collecting part" and "load supplying part". Due to the user-friendly layout, all design parameters can be changed quickly and easily for the influence on system efficiency. For the reliability, ASOLis compared with experimental result. As a result, ASOLis is expected to be used as a vital tool for the design and analysis of active solar heating system.

• 한국생산제조학회지
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• 제9권6호
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• pp.96-102
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• 2000

Spinning mechanism is generally used in coasting process on grass plates. Rebounding PR(Photo Resist) which leads to occur inferiority of coating process is caused by vibrational energy of whole coating system. In this study, the sensitivity analysis is performed to analyze and reduce vibrational terms in the spin coating system. The sensitivity analysis is bared on the numerical expression of this system. By the bond graph method. power flow of each system is represented by some basic bond graph elements. Any energy domain system is modeled using the unified elements. The modelled spin coater system is verified with power spectrum data measured by FFT analyzer. As the results of verifying model parameters and sensitivity analysis, principal factors causing vibration phenomenon are mentioned. A study on vibration method in the spin coating system is discussed.

• 컴퓨터교육학회논문지
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• 제7권4호
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• pp.43-50
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• 2004

다국어 질의 응답 시스템은 여러 언어의 질의에 대한 응답을 하는 시스템이다. LASSO 시스템은 다국어 질의응답 시스템 중의 하나이다. 본 논문은 LASSO 시스템을 위한 한국어 해석 시스템의 설계 및 구현에 관한 것이다. 질의 응답을 위한 한국어 해석 시스템은 한국어 질의를 처리할 수 있는 대화체 처리 기술이 필요하다. 그리고 다양한 분야의 질의에 대한 응답을 할 수 있는 범용의 시스템이어야 한다. 본 논문의 한국어 해석 시스템은 이와 같은 사항을 만족하기 위하여 심도 깊은 대화체 처리 기술보다 실용성이 높은 휴리스틱 규칙을 활용하였다. 이 시스템은 다국어 질의 응답 시스템의 한국어 인터페이스 역할을 하는 것으로 질의 응답 시스템의 목적에 맞게 설계, 구현되었다. 본 해석 시스템에 적용된 기술은 정보검색 분야와 한국어 해석 분야에 응용할 수 있다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권2호
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• pp.99-106
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• 2004

Train control system in LRT (Light Rail Transit) is developed as a part of "Light Rail Transit System Development Project". But there was no specific requirement representing the system safety. Because system safety must be ensured before the customization, we applied the system to a officially recognized specific procedure, such as "A Guideline to Ensure the Safety of Train Control System in Korea" that was officially announced by KNR (Korea National Railroad) in 2001. We should draw system safely requirement to guarantee system safety for the first time. In this paper, the hazard identification and analysis to derive the safety requirement on LRT train control system are carried out following the KNR guideline. To analyze hazard, we have to deduce system functions, identify related hazards, derive the effects of the hazards, analyze current risk, define the target risk of the system, and deduce the alternative plans to reduce the effects of the hazards. After the hazard analysis following the upper procedure, 30 hazards are identified and analysed. Especially detailed analysis on train collision that is a main hazard of the train control of system is specially carried out.