• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.688-696
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• 2017

This paper presents an integrated roll-pitch-yaw autopilot using an equivalent based sliding mode control for skid-to-turn nonlinear time-varying missile system with lumped disturbances in its six-equations of motion. The considered missile model are developed to integrate the model uncertainties, external disturbances, and parameters perturbation as lumped disturbances. Moreover, it considers the coupling effect between channels, the variation of missile velocity and parameters, and the aerodynamics nonlinearity. The presented approach is employed to achieve a good tracking performance with robustness in all missile channels simultaneously during the entire flight envelope without demand of accurate modeling or output derivative to avoid the noise existence in the real missile system. The proposed autopilot consisting of a two-loop structure, controls pitch and yaw accelerations, and stabilizes the roll angle simultaneously. The Closed loop stability is studied. Numerical simulation is provided to evaluate performance of the suggested autopilot and to compare it with an existing autopilot in the literature concerning the robustness against the lumped disturbances, and the aforesaid considerations. Finally, the proposed autopilot is integrated in a six degree of freedom flight simulation model to evaluate it with several target scenarios, and the results are shown.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.9
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• pp.1-7
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• 2012

In this paper, we present a new lighting control method considering ambient light in addition to the required lighting illumination for efficient energy saving of a LED stand. We estimate accurate environmental illuminance using a cheap illuminance sensor by modeling measured- and actual-illuminance using quadratic polynomial approximation. The relation between PWM(Pulse Width Modulation) duty ratio and illuminance intensity is modeled by a linear model. Illumination of the LED stand is controlled by estimating the difference of required illumination and the estimated ambient illumination. The developed LED stand has reduced electric energy consumption compared with a conventional manually controlled LED stand with the same lighting source. In addition, human subject evaluation shows that the LED stand, which is applied the proposed method, is more satisfactory than conventional ones since the proposed automatic controlled illumination produce more accurately required lighting and it is convenient.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.2
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• pp.201-206
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• 2010

PLCs are special purpose microcontrollers used in most automatic control systems such as plants, embedded systems, and intelligent buildings. LD is one of the most popular languages among PLC languages. For now LD programs are mainly verified by simulation and testing which has a lot of limitation. This paper describes how to translate a given LD program into an input of a model checker so that LD program is verified by model checking. We define formal semantics of LD programs and SMV models and specify a formal definition of the translation function which preserves semantics between LD programs and SMV models.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1112-1118
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• 2004

Automated container terminals have been developed over the world years and many countries are interested in them because the amount of containers exported or imported is rapidly increasing. The conventional container terminals were not designed to handle this kind of heavily many containers. They would face many structural problems soon or later, although they have been managed to do well so far. One of the most important things in automated container terminal is the handing equipments able to transfer many containers efficiently. Those are maybe automated transfer cranes, automatic guided vehicles and automated quay-side cranes. The word 'automated' means the equipment is operated without drivers and those equipments are able to work without any interruption in working schedule. Through the researches on the conventional transfer cranes, we decided that the structure of conventional transfer cranes is not proper in automated container terminal and it is not possible to handle so many container in limited time. Therefore we have been studying on the proper structure of the automated container for past several years and a new type of transfer cranes has been developed. Design concept and control method of the new crane are introduced and experimental results are presented in this paper.his paper.

• Journal of the Korea Society of Computer and Information
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• v.7 no.4
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• pp.108-114
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• 2002

After automatic translation system for hangul's romanization based on the World Wide Web converting korean-word, sentence, document to Transliteration letters by applying algorithm based phonological principles. even though a user do not know the basic principles of the usage of Korean-to-Romanization notations, It refers to corresponding character table that has been currently adopted the authority's standard proposition for Korean-to-Romanization notation rule concurrently, add to make possible to convert a machinized code as well. It provides font for toggling Korean-English mode, insert-edit mode by assigning ASCII codes and Unicode are hardly used to them. This program could be made in C++ progamming language and Unified Modeling Language to implement various font. font-expanding and condensing. alternative printing.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.358-368
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• 2012

On most construction sites, the arrangement of tower cranes is decided by site engineers based on their own experience, which can cause cost overruns and delays in the lifting work. Although many researchers have conducted studies on tower crane arrangement using computer modeling and knowledge-based expert systems as well as mathematical models, no research has aimed to develop an algorithm to identify an optimum solution among several alternatives for installation areas of tower cranes satisfying the conditions of lifting work. The objective of this study is to develop an automatic arrangement algorithm for tower cranes used in high-rise apartment construction. First, as a new concept, a possible installation area of tower cranes was suggested. Second, after proposing several alternatives based on the installation points suggested in this study, an algorithm analyzing the economic feasibility of tower cranes was developed considering the rental, installation and removal costs. Third, a case study was conducted to prove the validity of the developed algorithm for selecting and installing an effective set of tower cranes at minimum cost.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.2
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• pp.106-116
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• 1998

A position control algorithm of a flexible manipulator is studied. The proposed algorithm is based on an ACFAC(Automatic Constructed Fuzzy Adaptive Controller) system based on the neural network learning algorithms. The proposed system learns membership functions for input variables using unsupervised competitive learning algorithm and output information using supervised outstar learning algorithm. ACFAC does not need a dynamic modeling of the flexible manipulator. An ACFAC is designed that the end point of the flexible manipulator tracks the desired trajectory. The control input to the process is determined by error, velocity and variation of error. Simulation and experiment results show a robustness of ACFAC compared with the PID control and neural network algorithms.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.11
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• pp.631-639
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• 2013

This study derives quality checking items in Building Mechanical Systems Design Criteria, and suggests quality criteria to review BIM models in the duct system of an air conditioning system for rule-based automatic checking. First, components for the duct system of an air conditioning system were reviewed, and the quality checking items were drawn from Building Mechanical Systems Design Criteria, through assessment according to object, attribute and relationship composing the BIM model. Second, quality checking types were derived, by analyzing the quality checking items and Rule set of the Solibri Model Checker. Finally, methods of algorithm functioning for checking the BIM models for mechanical systems in computers were drawn, and Elements to comprise the quality checking criteria (rule) were suggested. This study means that that checking items are derived from domestic criteria, and a way for the development process of determining quality checking criteria (rules) is suggested.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.7
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• pp.674-679
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• 2008

In this paper, we introduce a new design approach for self-sustained resonant accelerometer, that takes advantage of the automatic gain control (AGC) loop to achieve a stabilized oscillation dynamics. Fundamental idea of this accelerometer is to maintain uniform amplitude of oscillation under input accelerations. Through system modeling and loop transformation considering the envelope of oscillation, the controller is designed to maintain uniform amplitude in oscillation under dynamic input acceleration. The simulation results demonstrate the feasibility of the proposed accelerometer design, which is applicable to control grade inertial measurement system in industrial and civil application fields.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.689-694
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• 1994

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.