• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제17권4호
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• pp.221-237
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• 2013

In this paper an asymptotic numerical method named as Initial Value Method (IVM) is suggested to solve the singularly perturbed weakly coupled system of reaction-diffusion type second order ordinary differential equations with negative shift (delay) terms. In this method, the original problem of solving the second order system of equations is reduced to solving eight first order singularly perturbed differential equations without delay and one system of difference equations. These singularly perturbed problems are solved by the second order hybrid finite difference scheme. An error estimate for this method is derived by using supremum norm and it is of almost second order. Numerical results are provided to illustrate the theoretical results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.142-147
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• 1996

For prediction and control of sound, acoustic systems must be modeled. Because sound systems like exhaust systems are very difficult to calculate mathematically, this study presents a method to determine experimentally the order of poles by transfer function. When designing a control system by traditional methods the exact model order and coefficient of the system to be controlled must be determined. But in acoustic systems, where systems to be controlled are very complex, mathematical interpretation is almost always impossible. Therefore transversal filters using trial and error methods to determine model order of a system are used to design a system. Compared to mathematical models with poles, transversal filters, in which the model order becomes relatively large, have the disadvantage of prolonged processing time and marked time delay. This study presents a method to determine experimentally the order of poles in a system model with poles and zeroes. Also, the validity of this method was verified mathematically and confirmed by application in general simple models and acoustic tube simulators.

• 산업경영시스템학회지
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• 제35권1호
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• pp.47-56
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• 2012

Service Parts Management is defined as a supply management associated with service parts from the part suppliers to the final customer. A series of process to improve the customer service level by forecasting the demand and to minimize cost by maintaining the inventory level is included. Uniqueness such as missing value correction, the data pattern analysis and planned order system is designed and implemented. Main feature of order management system is to calculate order amount and order time based on selection of optimal forecasting algorithm.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.283-288
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• 2002

This paper has shown that the impulse and the unit step responses of 2nd-order systems can be computed by an analytic method. Three different 2nd-order systems are investigated: the prototype system, the system with one LHP(left half plane) real zero and the system with one RHP(right half plane) real zero. It has also shown that the effects of the LHP or the RHP zero are very serious when the zero is getting closer to the origin on the complex plane. Based on these analytic results, this paper has presented two sufficient and necessary conditions for 2nd-order linear SISO(single-input/single-output) stable systems to have the nonovershooting and the monotone nondecreasing step response, respectively. The latter condition can be extended to the sufficient conditions for the monotone nondecreasing step response of high-order systems.

• 산업경영시스템학회지
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• 제20권41호
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• pp.95-102
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• 1997

This paper deals with an order picking system in an automated storage and retrieval system(AS/RS). For the order picking system, two fundamental policies, the batching and the picking policies, must be selected. The batching policy determines the manner in which orders are combined for picking in each trip of picking machine. The picking policy determines the sequence of all items in each group of orders. Most of studies for the batching policy doesn't consider dynamic arrivals and due dates of orders. Therefore, we present an batching policy which considers dynamic arrivals and due dates of orders. The presented batching policy is efficient for the automated storage and retrieval system which is connected with a manufacturing system.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 2000년도 추계학술대회
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• pp.1.4-4
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• 2000

We present an autonomous distributed manufacturing system to plan the manufacturing process and the schedule based on a customer order, which considers the system efficiency as well as to the flexibly. In our system, an intermediate conceptual agent called process agent is introduced, of which the role is to create a plausible alternative for the working group to fulfill the given order. The process related decision such as process sequence, allocated facilities, schedule and cost is also made simultaneously. Given an order, several these process agents are created, and the optimum on is selected through a bidding mechanism. As a criterion of such a decision-making, we consider a concept of value which is determined by several factors such as cost, delivery, working ratio and so forth. Every agent consisting of the system makes decisions and actions so as to maximize its possessing value, and the overall behavior of the system is controlled by the value distribution.

• 품질경영학회지
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• 제19권2호
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• pp.133-137
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• 1991

In this paper, the queueing system in series is studied. The system is a tandem queueing system which has three stations. In system, one service station has a general distributions and two service stations have exponential distribution. Each station has a single server. The customer arrives with Poisson process and is serviced sequentially. It is assumed that the order of stations does not affect the quality of services. Using the light traffic approximations, the optimal order of the system which has the three stations is decided.

• Journal of Advanced Marine Engineering and Technology
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• 제18권4호
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• pp.77-83
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• 1994

In this paper, an optimal control of first order systems is discussed. The control system comprises a main controller and an auxiliary controller. The main controller is designed based on the LQ control scheme including an integrator to remove the off-set. The non-linear auxiliary controller is added parallely to the main controller to obtain a finite time settling control. The control parameters under variation of the system and various coefficients of the performance indices are computed numerically, and the control responses for the system with the proposed controllers demonstrated the usefulness of the control method.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.240-242
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• 2021

최근 대부분의 매장에서 직원과 고객이 직접 대면하여 주문 하는 시스템이 사라지고 무선 주문 시스템인 키오스크가 도입되고 있다. 하지만 매장에서 서비스하고 있는 Drive-Thru는 아직까지 직원과 고객이 직접 소통을 하여 주문 하는 시스템을 가지고 있다. 본 논문에서는 Drive-Thru의 직원과 고객이 직접 소통하는 부분을 QR-Code를 이용하여 고객이 직원과 대면하지 않고 주문을 하는 Drive-Thru 시스템의 설계를 제안한다. 비대면 Drive-Thru 시스템은 매장 내의 직원을 최소화하여 더욱 자동화 된 시스템 제공을 목적으로 한다. 이에 따라 고객들은 더욱 정확한 서비스를 제공 받으며 소비의 질을 높일 수 있는 효과를 지닌다.

• Computational Structural Engineering : An International Journal
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• 제3권1호
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• pp.1-7
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• 2003

For system identification of large structures, it is not practical to identify the entire structure due to the prohibitive computational time and difficulty in numerical convergence. This paper explores the possibility of performing system identification at substructure level, taking advantage of reduction in both the number of unknowns and the number of degrees of freedom involved. Another advantage is that different portions (substructures) of a structural system can be identified independently and even concurrently with parallel computing. Two substructural identification methods are formulated on the basis whether substructural approach is used to obtain first-order or second-order model. For substructural first-order model, identification at the substructure level will be performed by means of the Observer/Kalman filter Identification (OKID) and the Eigensystem Realization Algorithm (ERA) whereas identification at the global level will be performed to obtain second-order model in order to evaluate the system's stiffness and mass parameters. In the case of substructural second-order model, identification will be performed at the substructure level throughout the identification process. The efficiency of the proposed technique is shown by numerical examples for multi-storey shear buildings subjected to random forces, taking into consideration the effects of noisy measurement data. The results indicate that both the proposed methods are effective and efficient for damage identification of large structures.