• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.55-70
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• 2006

In this paper, we propose a new access control security architecture for supporting flexibility in Secure Operating Systems. By adding virtual access control system layer to the proposed security architecture, various access control models such as MAC, DAC, and RBAC can be applied to Secure Operating Systems easily. The proposed security architecture is designed to overcome the problem of Linux system's base access control system. A policy manager can compose various security models flexibly and apply them to Operating Systems dynamically. Also, the proposed architecture is composed of 3 modules such as access control enforcement, access control decision, and security control. And access control models are abstracted to hierarchy structure by virtual access control system. And, we present the notation of policy conflict and its resolution method by applying various access control model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.575-577
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• 2013

Recently most of the hand-held smart devices have WiFi communication facility. This makes WiFi AP(access point) popular and cheaper than before. These circumstance launches some services with AP providing location based services and device control services. In this paper, we propose a AP based control system. The control system consists of AP's, AP controller and Android application program. The AP can collect MAC address information of the associated smart devices and control connected devices. The AP controller maintains DB for smart device position information and device control information. Finally Android application program provides users location based service and device control service.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1598-1601
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• 2005

In this paper, a heterogeneous home network control system using HNCP is proposed and implemented. A power line and 802.15.4 are used as media for the system. Information about home environment gathered by sensors is transferred to a power line connected device through the 802.15.4. HNCP stimulate the home network based on the both media. Sensor device definition for the HNCP address and message set is proposed. TinyOS supports the HNCP stack on the wireless sensor board. The home network control system implemented with these techniques has a benefit of user friendly operation of home appliances based on the sensing data. Implementation and experiment shows validity of the system.

• Journal of Power Electronics
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• v.11 no.4
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• pp.456-463
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• 2011

Grid-connected converters have widely adopted LCL filters to acquire high harmonic suppression. However, the LCL filter increases the system order so that the design of the system stability would be complicated. Recently, sole-loop control strategies have been used for grid-connected converters with L or LC filters. But if the sole-loop control is directly transplanted to grid-connected converters with LCL filters, the systems may be unstable. This paper presents a novel dual-loop power control strategy composed of a power outer loop and a current inner loop. The outer loop regulates the grid-connected power. The inner loop improves the system stability margin and suppresses the resonant peak caused by the LCL filter. To obtain the control variables, a single-phase current detection is proposed based on PQ theory. The system transfer function is derived in detail and the influence of control gains on the system stability is analyzed with the root locus. Simulation and experimental results demonstrate the feasibility of the proposed control.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2211-2220
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• 1998

This paper presetns an adaptive critic self-learning control system with cerebellar model articulation controller (CMAC)-based decoder integrated with the associative search element (ASE) and adatpive critic element(ACE)- based scheme. The tast of the system is to balance a pole that is hinged to a movable cart by applying forces to the cart's base. The problem is that error feedback information is limited. This problem can be sloved when some adaptive control devices are involved. The ASE incorporates prediction information for reinforrcement from a critic to produce evaluative information for the plant. The CMAC-based decoder interprets one state to a set of patways into the ASE/ACE. These signals correspond to te current state and its possible preceding action states. The CMAC's information interpolation improves the learning speed. And design inverted pendulum hardware system to show control capability with neural network.

• Asia pacific journal of information systems
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• v.9 no.1
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• pp.17-38
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• 1999

While the value of information technology has long been a hot issue, few solid results have been found as of yet. It is partly due to methodological factors and model underspecifcation. This study empirically develops a ITS(information technology structure) taxonomy and investigates the relationships between ITS taxonomy and business performance in the Korean firms. Among factors that impact business performance, organization structure and control system are selected and they are hypothesized to moderate-the relationships between ITS taxonomy and business performance. By surveying 91 manufacturing firms and applying hierarchical cluster analysis, four ITS are identified : centralized, decentralized, centralized cooperative, decentralized cooperative. ANOVA, correlation analysis and crosstable analysis say the presence of moderating effect of organization structure and control system. Cooperative ITS is best in business performance. Centralized ITS is related to functional organizational form. Decentralized ITS is related to product organizational form with decentralized decision making, Centralized cooperative ITS is related to matrix organizational form. Decentralized cooperative ITS is related to matrix organizational form with high integration. These findings have implications for the opportunities and challenges to match information technology with organization structure and control system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.92-99
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• 2014

The paper is related to smart maximum power system based on program logic. Especially, this system compares the total demand power with the target power by using the signal from the digital kilo watt meter. Based on the power information by the maximum power control equipment the consumed future power is anticipated. In addition, through consumed future power the controllable target power is set, and it applies on the maximum power control equipment. User or manager would control the load efficiently through the simple programming which could control load based on the control sequence and relay. To begin with the conventional maximum power control algorithm is surveyed, and the smart maximum power control system based on program logic is used, and the new algorithm from full load to proportion shut down is proposed by using PLC program. the validity of the proposed control scheme is investigated by both simulation results.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.235-238
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• 1996

In this paper, a new optimization method which is a kind of random searching is presented. The proposed method is called RasVal which is an abbreviation of Random Search Method with Variable Seaxch Length and it can search for a global minimum based on the probability density functions of searching, which can be modified using informations on success or failure of the past searching in order to execute intensified and diversified searching. By applying the proposed method to a nonlinear crane control system which can be controlled by the Universal Learning Network with radial basis function(R.B.P.), it has been proved that RasVal is superior in performance to the commonly used back propagation learning algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1264-1268
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• 2004

This paper presents a wafer motion modeling of the transfer unit and the control unit in the clean tube system, which was developed as a means for transferring the air-floated wafers inside the closed tube filled with the super clean airs. The motion in the transfer unit is modeled as a mass-spring-damper system where the recovering force by air jets issued from the perforated plate is modeled as a linear spring. The motion in the control unit is also modeled as another mass-spring-damper system, but in two dimensional systems. Experiments with a clean tube system built for 12-inch wafers show the validity of the presented force and motion models.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.781-785
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• 1989

In the field of control technology, too, it is about time that the students should free themseleves from the paradigm of Newtonian mechanics. Otherwise, they might fail to grasp the essence of control. Now, let us consider the essence of control. Control consists of manipulating a particular object, matter, energy of environment on the basis of certain medium information. (measurement data, force, etc.) So, we shall look into the methods of manipulation. Here, we consider natural control, constraining control, and hybrid control as basic methods of manipulation. In this paper, we would like to put forward the daring proposal that it's called a Holon-type hybrid control system. It is intended to control a plat with complicated or unknown characteristics where a conventional control theory is not easy to apply. A prototype system has been developed and applied to a real plant. The control system is a multi-layer system. Each layer includes different control input. The important features of the system are as follows: 1) Each layer behaves autonomously and also cooperates with each other to optimize the whole plant. 2) The controller optimizes a plant without mathematical models when these models are not easy to obtain.