• Journal of Korean Library and Information Science Society
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• v.10
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• pp.157-191
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• 1983

The purpose of the study is to build a general cost a counting model for university libraries, to clarify the possible areas of its a n.0, pplication by employing job cost accounting and process cost accounting methods. System analysis is performed as to the fields of acquisition, processing (cataloging & classification), and book shelving system. The existing operation processes and time required for each operation of these three systems are analyzed, from which detailed system flowcharts were drawn and job descriptions and the content of job were identified. The results of the study can be summarized as follows: (1) The processing time of one book in each systems: Oriental books. a. Acquisition system. the time required the time required in case of job cost case of job cost accounting after purchasing, 8 min. 21 sec. the time required in case of process cost accounting 15 min. 7 sec. b. Processing system. the time required for non-duplicate, 34 min. 40 sec. the time required for duplicate, 8 min. 49 sec. the time required for purchasing of more than the time required two copies at a time. 4 min. 44 sec. c. Book shelving system. the time required. 1 min. 43 sec. Western books. a. Acquisition system the required in case of job cost accounting, 9 min. 1 sec. the time required in case of process cost accounting. 15 min. 7 sec. b. Processing system. the time required for non-duplicate, 32 min. 58 sec. the time required for duplicate, 9 min. 26 sec. the time required for purchasing of more than two copies at a time. 5 min. 33 sec. c. Book shelving system. the time required. 1 min. 43 sec. (2) Total sum of processing time and processing cost per book. Oriental books (including material cost) the time required. cost. a. non-duplicate, 51 min. 30 sec. 2, 791 won b. duplicate, 25 min. 39 sec. 1, 580 won c. purchasing of more than two copies as a time, 21 min. 34 sec. 1, 368 won Western books(including material cost) a. non-duplicate, 49 min. 48 sec. 3, 189 won b. duplicate, 26 min. 16 sec. 1, 846 won c. purchasing of more than two copies at a time. 22 min. 23 sec. 1, 388 won

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.5
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• pp.190-196
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• 2002

In this paper, the response characteristics of CAN-based feedback control system are analyzed when message time delays through the network are considered. The message time delays are composed of computation time delay and communication time delay. The application layer of CAN communication is modeled mathematically to analyze two time delays, and the communication time delay is redefined under several assumption conditions. The CAN-based feedback control system is proposed as a target system that is the machining system with the three axes. The response characteristics of time delays in the proposed system are analyzed through computer simulations, and can be improved by the compensation using the PID tuning method to satisfy the design specifications of the system.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.1-9
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• 1998

This paper is focussed on the problem of robustly stabilizing a transformable linear time-varying system. The considered system is a class of state feedback transformable linear systems. First, the real linear time-varying system is transformed into the linear time invariant system composed with the time-invariant linear part and the time-varying uncertainty part. Second, the solution to a quadratic stabilization problem in the transformed linear system is give via' Lyapunov methods. Then this solution is used to construct a stabilizing linear control law for the real linear time-varying system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.702-706
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• 1996

The King Sejong's Striking water-clock was named for its distictive day and night time announcing system. Its time announcing system generates acoustic and visual signals for the twelve double hour, and combinations of two different acoustic signals for the five night watches, The mechanism of this signal generation system is triggered by a copper ball which is mechanically digitized time keeping signal, and is generated from the water clock. The time announcing system consisted four parts: 1) the mechanical amplifier which changes small copper to heavy steel ball, 2) day time announcing system, 3) night time announcing system, 4) sounding mechanism. The time announcing system of King Seong's Striking Clepsidra is remotely related to the Arabic clock system, however, it does have world-widely distictive mechanisms of its era, such as mechanical amplifier, self-weight rachet mechanism, and resetable mechanical computer etc.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.10
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• pp.21-30
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• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2215-2217
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• 2004

In this paper, a systematic design approach based on the parallel distributed compensation technique is proposed for chaotifying a general continuous-time Takagi-Sugeno (TS) fuzzy system. The fuzzy parallel distributed compensation controller (FPDCC) is composed of the feedback gain and time-delay feedback. The verification of chaos in the controlled continuous-time TS fuzzy system is done by the following procedures. First, we establish an asymptotically approximate relationship between a time-delay continuous-time TS fuzzy system and a discrete-time TS fuzzy system. Then, Marotto theorem is applied. Therefore, the generated chaos is in the sense of Li and Yorke. The boundedness in the controlled continuous-time TS fuzzy system is also proven via its associated discrete-time TS fuzzy system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.55-63
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• 2019

This paper develops an algorithm to determine the batch size of the batch process in real time for improving production and efficient control of production system with multiple processes and batch processes. It is so important to find the batch size of the batch process, because the variability arising from the batch process in the production system affects the capacity of the production. Specifically, batch size could change system efficiency such as throughput, WIP (Work In Process) in production system, batch formation time and so on. In order to improve the system variability and productivity, real time batch size determined by considering the preparation time and batch formation time according to the number of operation of the batch process. The purpose of the study is to control the WIP by applying CONWIP production system method in the production line and implements an algorithm for a real time batch size decision in a batch process that requires long work preparation time and affects system efficiency. In order to verify the efficiency of the developed algorithm that determine the batch size in a real time, an existed production system with fixed the batch size will be implemented first and determines that batch size in real time considering WIP in queue and average lead time in the current system. To comparing the efficiency of a system with a fixed batch size and a system that determines a batch size in real time, the results are analyzed using three evaluation indexes of lead time, throughput, and average WIP of the queue.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.5 no.1
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• pp.04-10
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• 1987

We consider a time sharing computer system with a single processor where tasks ofK different types arrive at the system according to independent time homogeneous Poisson processes from outside. A task, after given a quantum for processing, leaves the system, or changes the type and rejoins the system according to specified probabilitycs. While many existing priority time sharing models determine the priorities of tasks strictly by their service time requirements, this paper develops a new scheduling rule wherein the importances or urgencies in addition to the service time requirements of tasks are counted, by inposing an appropriate reward structure on the system. Also presented is the algorithm through which to determine the rankings of K types according to this new scheduling rule.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.115-118
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• 2004

In this paper, a systematic design approach based on parallel distributed compensation techniques is proposed for anticontrol of chaos in a general continuous-time Takagi-Sugeno (TS) fuzzy system. The verification of chaos in the controlled continuous-time TS fuzzy system is done by the following procedure. First, we establish an asymptotically approximate relationship between a continuous-time TS fuzzy system with time-delay and a discrete-time TS fuzzy system. Then Marotto theorem is applied. The boundedness in the controlled continuous-time TS fuzzy system is also proven via its associated discrete-time TS fuzzy system.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.2
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• pp.123-130
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• 1999

In discrete-time controlled system, sampling time is one of the critical parameters for control performance. It is useful to employ different sampling rates into the system considering the feasibility of measuring system or actuating system. The systems with the different sampling rates in their input and output channels are named multirate system. Even though the original continuous-time system is time-invariant, it is realized as time-varying state equation depending on multirate sampling mechanism. By means of the augmentation of the inputs and the outputs over one period, the time-varying system equation can be constructed into the time-invariant equation. The two multirate formulations have some trade-offs in the simplicity to construct the controller, the control performance. It is good issue to determine the suitable formulation in consideration of performance of them. In this paper, the two categories of multirate formulations will be compared in terms of the linear quadratic (LQ) cost function. The results are used to select the multirate formulation and the sampling rates suitable to the desired control performance.