• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.8
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• pp.54-65
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• 1992

A huge amount of multiplications is required for 2-D filtering on the image data, making it difficult to implement a real-time quincuncial interpolator. In this paper, efficient design technique and VLSI structures for 2-D multipleierless filter are presented. In the filter design, by introducing an efficient scheme for discretizing the frequency response of the prototype filter, it is shown that a significant amount of the computational burden required in the conventional techniques, such as local search, branch and bound techniques, could be saved. In the case of 5$\times$5 filter, it is found that the design technique described in this paper could save about 80% of the computation time, compared to the conventional methods, while providing a comparable performance. For a hardware implementation, two different VLSI structures for 2-D multiplierless filter are also introduced in the paper : One is for block parallel processing and the other for scan-line parallel processing. In both structure, the AP(area-period) figure improves over Wu's structure[4].

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1040-1047
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• 2007

This paper presents ripple-free method that can occur in multirate controller design. The conventional multirate input controller has the problem that the ripple occurs in track-following because of chattering phenomenon in control input signal. In order to resolve the problem of rippling, it was proposed to eliminate the ripple phenomenon using feedforward compensator. This paper makes explains problems in conventional ripple-tree multirate controller and introduces a multirate controller design method applying lifting technique based on current estimators in condition space. Using the ripple-tree multirate controller, we show that chattering does not occur in the control input signal through applying the final value theorem from the viewpoint of discrete-time transformation. Also, this study proves that the ripple of the proposed controller decreases with the increase of this sampling frequency and, when sampling frequency is fixed, it decreases with the increase of the control input period.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.135-142
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• 2004

The apparent advantages of FRP (fiber reinforced plastics) composites over the conventional structural materials may be attributed to their high specific strength and stiffness. Other affordable properties of FRPs including an excellent durability make them particularly attractive for the structures in severe service conditions. Therefore, the material and sectional properties of a FRP structural component should be designed to meet its specific requirements and service conditions. This paper is performed the material property optimization under optimum design of pultruded FRP bridge deck section. In the problem formulation, an objective function is selected to minimize the maximum R(strength ratio). The thickness of layers, volumes of fibers and matrix fiber orientation, and stacking sequence of FRPs are used as the design variables. Strength ratio in the design code, material failure criteria and pultruded manufacture thickness are selected as the design constraints to enhance the material performance of FRP decks. From the results of the numerical investigation, we obtained the optimum deck section profile for conventional using object.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.408-416
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• 2002

Hydraulic performance of the pump with an inducer was predicted by 3-D Navier-stokes calculation. The evaluated pump was the single-stage centrifugal pump with a separated inducer to pressurize fuel (LCH4) in Turbo-pump system with a specific speed (Ns) of approximately 0.3[rad/s, m3/s, J/kg] and a suction specific speed(s) of 15[rad/s, m3/s, J/kg]. That conventional pump was designed with the combination of 1-D theory and empirical correlation. In this study, preliminary design to select key parameters such as inlet flow coefficient was reviewed by investigating sets of the known design methods to achieve appropriate suction performance, and the performance of newly designed inducer and impeller was compared with the old one, using CFD method. The numerical results showed that the hydraulic efficiency of the new pump was predicted $5.5\%$ higher than that of the conventional one, through design parameter re-selection, configuration improvement and blade loading control

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.376-379
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• 2001

This paper describes the design and fabrication process of super water-saving toilet bowl system by the theory of inventive problem solving (TRIZ). The physical contradiction in TRIZ is defined to obtain the conceptual design for saving water in toilet bowl system with preventing the bad smell from septic tank. The super water-saving toilet bowl system is obtained by using the separation principle in time for resolving the physical contradiction. The consumption of water in the prototype system fabricated, is estimated about $3{\ell}$ comparing with $13{\ell}$ of that in conventional toilet bowl system. The noise from water in the prototype toilet bowl system is decreased by 1/3 of that in conventional toilet bowl system.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.304-312
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• 2000

An inverse finite element approach is employed to efficiently design the optimum blank shape and intermediate shapes from the desired final shape in multi-stage elliptic cup drawing processes. The multi-stage deep-drawing process is difficult to design with the conventional finite element analysis since the process is very complicate with the conventional finite element analysis since the process is very complicated with intermediate shapes and the numerical analysis undergoes the convergence problem even with tremendous computing time. The elliptic cup drawing process needs much effort to design sine it requires full three-dimensional analysis. The inverse analysis is able to omit all complicated and tedious analysis procedures for the optimum process design. In this paper, the finite element inverse analysis provides the thickness strain distribution of each intermediate shape through the multi-stage analysis. The multi-stage analysis deals with the convergence among intermediate shapes and the corresponding sliding constraint surfaces that are described by the analytic function of merged-arc type surfaces.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.209-213
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• 2017

The delay-insensitive Null Convention Logic (NCL) asynchronous design as one of innovative asynchronous logic design methodologies has many advantages of inherent robustness, power consumption, and easy design reuses. However, transistor-level structures of conventional NCL gate cells have weakness of high area overhead and high power consumption. This paper proposes a new NCL gate based on power gating structure. The proposed $4{\times}4$ NCL multiplier based on power gating structure is compared to the conventional NCL $4{\times}4$ multiplier and MTNCL(Multi-Threshold NCL) $4{\times}4$ multiplier in terms of speed, power consumption, energy and size using PTM 45 nm technology.

• Journal of Power Electronics
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• v.10 no.3
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• pp.306-312
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• 2010

In this paper, the design of an optimum single input Fuzzy controller for application in dc to ac converters is presented. Contrary to conventional Fuzzy controllers, the proposed controller has a smaller number of rules and tuning parameters but is capable of performing identically to a conventional controller. These benefits lead to a simpler controller design. The controller is designed as a PI controller for small-signal disturbances. However, for optimum large-signal performance, heuristic tuning is used. The tuning is less complicated and hence optimum large-signal performance is achievable. The system is simulated and a hardware prototype was developed for comparison purposes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.101-103
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• 2011

Various desired performances of concrete cannot be always obtained by current conventional mix proportion methods for recycled aggregate concrete (RAC). This paper suggests a new design method of mix proportion for RAC to reduce the number of trial mixes using genetic algorithm (GA) which has been an optimization technique to solve the multi-object problem. In mix design method by GA, several fitness functions for the required properties of concrete, i.e., slump, strength, price, and carbonation speed coefficient were considered based on conventional data or fitness function. As a result, various optimum mix proportions for RAC that meet required performances were obtained and the risk evaluation was also conducted for selected mixtures.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.969-972
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• 1988

A conventional robotic manipulator is usually a very complicated system whose dynamics is too computationally time consuming for dynamic analysis and real time control. The authors have proposed the general design criteria of the robot links which greatly simplify the robot dynamic characteristics. In this paper these design guidelines are applied to a 6 degree of freedom PUMA 560 robot in order to realize actual implementation of the design concept. Based upon the design concept, the dynamic equations of the redesigned robot were derived. Dynamic characteristics of two systems, the ideally designed and conventional robot, are compared with respect to the joint input torque characteristics and degree of the coupling between the robot joints.