• The Journal of Information Systems
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• v.16 no.1
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• pp.91-109
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• 2007

This study investigates the extent to which the implementation of enterprise resource planning(ERP) systems enhance the corporate performance by examining financial variables of the implemented firms against those of the control fm. A total of 346 observations were obtained from 160 firms, 80 implemented firms and 80 control firms, for the period of 1998-2002. Results from the study partly support the assertion that ERP improves the full spectrum of business functions such as selling, marketing, purchasing, warehousing, accounting and human resources by tightly integrating enterprise-wise information databases. First the profitability of the implemented group was different from that of the control group. The indicator (dummy) variable was able to explain the differences in total cash flows between the implemented group fm and the control group firms. Second, ERP turned out In improve the efficiency in managing assets. The indicator variable has the power in explaining the differences in the amount of accounts receivables between the implemented group firms and the control group firms. Third, the product turnover ratio of the implemented group was different from that of the control group. Fourth, the average value added per employee and the net income per employee of the implemented group firms were greats- than those of the control group firms. Finally, the average magnitude of the administrative expenses of the implemented group firms was smaller than that of the control group firms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2281-2301
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• 2014

In wireless ad hoc networks the nodes focus on achieving the maximum SINR for efficient data transmission. In order to achieve maximum SINR the nodes culminate in exhausting the battery power for successful transmissions. This in turn affects the successful transmission of the other nodes as the maximum transmission power opted by each node serves as a source of interference for the other nodes in the network. This paper models the choice of power for each node as a non cooperative game where the throughput of the network with respect to the consumption of power is formulated as a utility function. We propose an adaptive pricing scheme that encourages the nodes to use minimum transmission power to achieve target SINR at the Nash equilibrium and improve their net utility in multiuser scenario.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1644-1651
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• 2022

This paper focuses on the power-level control of nuclear power plants (NPPs) in the presence of lumped disturbances. An adaptive second-order nonsingular terminal sliding mode control (ASONTSMC) scheme is proposed by resorting to the second-order nonsingular terminal sliding mode. The pre-existing mathematical model of the nuclear reactor system is firstly described based on point-reactor kinetics equations with six delayed neutron groups. Then, a second-order sliding mode control approach is proposed by integrating a proportional-derivative sliding mode (PDSM) manifold with a nonsingular terminal sliding mode (NTSM) manifold. An adaptive mechanism is designed to estimate the unknown upper bound of a lumped uncertain term that is composed of lumped disturbances and system states real-timely. The estimated values are then added to the controller, resulting in the control system capable of compensating the adverse effects of the lumped disturbances efficiently. Since the sign function is contained in the first time derivative of the real control law, the continuous input signal is obtained after integration so that the chattering effects of the conventional sliding mode control are suppressed. The robust stability of the overall control system is demonstrated through Lyapunov stability theory. Finally, the proposed control scheme is validated through simulations and comparisons with a proportional-integral-derivative (PID) controller, a super twisting sliding mode controller (STSMC), and a disturbance observer-based adaptive sliding mode controller (DO-ASMC).

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3898-3906
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• 2023

The paper notes that the most common way of handling spent nuclear fuel (SNF) of power reactors is its temporary long-term dry storage. At the same time, the operation of the dry spent fuel storage facilities almost never use the modern capabilities of information systems in safety control and collecting information for the next studies under implementation of aging management programs. The author proposes a structure of an information system that can be implemented in a dry spent fuel storage facility with ventilated storage containers. To control the thermal component of spent fuel storage safety, a database structure has been developed, which contains 5 tables. An algorithm for monitoring the thermal state of spent fuel was created for the proposed information system, which is based on the comparison of measured and forecast values of the safety criterion, in which the level of heating the ventilation air temperature was chosen. Predictive values of the safety criterion are obtained on the basis of previously published studies. The proposed algorithm is an implementation of the information function of the system. The proposed information system can be used for effective thermal monitoring and collecting information for the next studies under the implementation of aging management programs for spent fuel storage equipment, permanent control of spent fuel storage safety, staff training, etc.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.38-47
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• 2003

Distributed problem solving is the cooperative solution of problem by a decentralized and loosely couped collection of knowledge-sources (KS's), located in a number of distinct processor nodes. The contract net protocol has been developed to specify problem-solving communication and control for nodes in a distributed problem solver. Task distribution is affected by a negotiation process, a discussion carried on between nodes with tasks to be executed and nodes that may be able to execute tasks In this paper, we present the coordination method among distributed intrusion detection system and firewall by the contract net protocol. The method enhances the intrusion detection performance and provides the communication methods. To mode IDS and firewall, security models hue been hierarchically constructed based on the DEVS (Discrete Event system Specification) formalism. Each ID agent cooperates through the contract net protocol for detecting intrusions. The IDS which detects the intrusion informs to firewall, so the harmful network traffic is blocked. If an agent detects infusions, the agent transfers attacker's information to a firewall. Using this mechanism attacker's packets detected by In can be prevented from damaging the network.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.541-544
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• 2006

본 논문에서는 모바일 기기들을 사용하여 언제 어디서나 PC에 접속하여 컴퓨터 시스템을 제어 할 수 있는 시스템을 구현하였다. 이 시스템은.NET과 데이터베이스 기반의 모바일 시스템 설계로 IP address와 데이터베이스를 활용한 모바일 접속을 통하여 PC를 제어하기 위한 모바일 원격 제어 시스템이다. 우선적으로 PC의 전반적인 시스템 제어가 아닌 멀티미디어(음악, 이미지, 동영상 파일)와 Shutdown 실행을 제어하는 기능을 구현하였다.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.141-150
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• 2013

There is mounting evidence that complex computer system displays in control rooms contribute to cognitive complexity and, thus, to the probability of human error. Research shows that reaction time increases and response accuracy decreases as the number of elements in the display screen increase. However, in terms of supporting the control room operator, approaches focusing on addressing display complexity solely in terms of information density and its location and patterning, will fall short of delivering a properly designed interface. This paper argues that information complexity and semantic complexity are mandatory components when considering display complexity and that the addition of these concepts assists in understanding and resolving differences between designers and the preferences and performance of operators. This paper concludes that a number of simplified methods, when combined, can be used to estimate the impact that a particular display may have on the operator's ability to perform a function accurately and effectively. We present a mixed qualitative and quantitative approach and a method for complexity estimation.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1269-1271
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• 1996

This paper presents a visual servoing combined by evolutionary algorithms and neural network for a robotic manipulators to control position and orientation of the end-effector. Using the multi layer feedforward neural network that permits the connection of other layers, evolutionary programming(EP) that search the structure and weight of the neural network, and evolution strategies(ES) which training the weight of neuron, we optimized the net structure of control scheme. Using the four feature image information from CCD camera attached to end-effector of RV-M2 robot manipulator having 5 dof, we generate the control input to agree the target image, to realize the visual servoing. The validity and effectiveness of the proposed control scheme will be verified by computer simulations.

• Management Science and Financial Engineering
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• v.14 no.1
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• pp.35-63
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• 2008

We discuss the problem of selecting profitable customer orders arriving at a company providing two classes of services. For an arriving customer order for the first class, the company 1) makes a decision whether to accept or reject it (admission control), or 2) decides a price of the order to offer to an arriving customer (pricing control). The customer order undergoing processing in the system may be cancelled owing to unavoidable circumstances with the customer. The second class of service is provided as a sideline, which prevents the server from being idle when all the customer orders for the first class are completed and delivered. This yields the sideline profit. We discuss both admission control and pricing control problems in an identical framework as well as examine the structure of the optimal policies maximizing the total expected present discounted net profit gained over an infinite planning horizon.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.7
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• pp.944-949
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• 2012

As modern power systems become large and complicated, the automated voltage and reactive power control system is required in most developed countries due to the recent amazing progress of computer net works and information thechnology. So far the voltage control has been depend on human operator in korean power system. This paper presents an intelligent voltage control system based on sensitivity analysis and artificial intelligence technology. Detailed state space modeling technique is discussed and a new performance index is proposed to speed up the searching performance of the expert system. As the searching strategy is very important factor of the speed of expert system the least first search algorithm is applied using this performance index. The intelligent voltage control system is applied to the Jeju power system. As a result, case studies showed a promissing application of the intelligent voltage control system.