• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.5
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• pp.422-428
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• 1988

An iterative learning control system is a control system which makes system outputs follow desired outputs by iterating its trials over a finite time interval. In a discrete time system, we proposed one method in which present control inputs can be obtained by a linear combination of the input sequence and time-shifted error sequence at previous trial. In contrast with a continous time learning control system which needs differential opreration of an error signal, the time shift operation of the error sequence is simpler in a computer control system and its effectiveness is shown by a simulation.

• Research in Mathematical Education
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• v.11 no.1
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• pp.75-85
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• 2007

This paper analyzes the difficulties with the learning of sequence and series of the second-year students who participated in a year long whole class at the university level. The research was carried out at the end of students' third semester. These students were randomly selected. They were applied to one paper and pencil test containing eight task items on sequence and series. In this study, qualitative method (case study design) was used to explore students' difficulties and misunderstandings in learning sequence and series. Students' responses to the questions were divided into three categories: These were "correct", "partial correct" and "false or no responses". Students' responses to the paper and pencil test were evaluated. The results show that students had difficulties and misunderstandings in series and sequence.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1098-1100
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• 2005

The floorplanning problem is an essential design step in VLSI layout design and it is how to place rectangular modules as density as possible. And then, as the DSM advances, the VLSI chip becomes more congested even though more metal layers are used for routing. Usually, a VLSI chip includes several buses. As design increases in complexity, bus routing becomes a heavy task. To ease bus routing and avoid unnecessary iterations in physical design, we need to consider bus planning in early floorplanning stage. In this paper, we propose a floorplanning method for topological constraint consisting of bus constraint and memory constraint. The proposed algorithms based on Genetic Algorithm(GA) is adopted a sequence pair. For selection control, new objective functions are introduced for topological constraint. Studies on floor planning and cell placement have been reported as being applications of GA to the LSI layout problem. However, no studies have ever seen the effect of applying GA in consideration of topological constraint. Experimental results show improvement of bus and memory constraint.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.190-198
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• 1989

Some Developments in computer aided procedures for cold forging process and tool design of rotationally symmetric cup shape parts are described. The developed system enables appropriate forging sequence to be determined automatically, together with details of corresponding preform, die and punch design. The computer program developed is interactive and written in BASIC. This system not only assist the heavy work of designers but greatly shorten the time of design.

• Physical Therapy Rehabilitation Science
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• v.8 no.4
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• pp.225-233
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• 2019

Objective: The purpose of this study was to examine the possible effects of incorporating short-term slow-abdominal respiration (SAR) into an exercise program, on balance and the cardiac-related autonomic nervous system (ANS). Design: Cross-over repeated measures design. Methods: Fifteen young and healthy adults were randomly assigned into two groups (7 in the C-R group, 8 in the R-C group), each of which carried out both control sequence (C) and respiration-experiment sequence (R) in the inverse order. In the C sequence, the subjects performed passive exercises and a general exercise program (P-GEP). In the R sequence, the subjects received a short-term SAR training session and then performed the respiration incorporated general exercises program (R-RGEP). Before and after both C and R sequences, the length and the area of the displacement of the center of pressure (COP) and heart rate variability parameters were measured. Results: The total length of the COP displacement in the left single-leg-standing condition showed a significantly greater reduction after R-RGEP in the respiration-experiment sequence than after the P-GEP in the control sequence (p<0.05). The mean heart rate was significantly reduced only after R-RGEP in the respiration-experiment sequence (p<0.05) Conclusions: The slow-abdominal-respiration, trained in a simple manner and integrated into the exercise program in a single session, showed partially positive immediate effects on balance stabilization. The decrease in heart rate indicated possible involvement of the parasympathetic ANS activation in the stability, although it is not enough to decide whether it is purely due to the controlled respiration.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.134-137
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• 1998

Caliber design in bar and rod rolling depends on the designer's experience, which in general is acquired through costly trial-and-error process. As a prerequisite for developing a scientific approach to caliber design, we present a finite element model to simulate 3-D deformation of bars and rods occurring in multi-pass sequence. The results are compared with measurements obtained from POSCO for to assess the solution accuracy. The comparison shows that the simulation results agree well experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.1
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• pp.19-30
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• 2015

A static synchronous compensator (STATCOM) applied to rapidly changing, highly unbalanced loads such as electric arc furnaces (EAFs), requires both positive-sequence and negative-sequence current control, which indicates fast response characteristics and can be controlled independently. Furthermore, a delta-connected STATCOM with cascaded H-bridge configuration accompanying multiple separate DC-sides, should have high performance zero-sequence current control to suppress a phase-to-phase imbalance in DC-side voltages when compensating for unbalanced load. In this paper, actual EAF data is analyzed to reflect on the design of current controllers and a pioneering zero-sequence current controller with a superb transient performance is devised, which generates an imaginary -axis component from the presumed response of forwarded reference. Via simulation and experiments, the performance of the positive, negative, and zero-sequence current control of a cascaded H-bridge STATCOM for EAF is verified.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.115-120
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• 1999

Multiple Sequence Alignment of DNA and protem sequences is a imnport'mt tool in the study of molecular evolution, gene regulation. and prolein suucture-function relationships. Progressive pairwise alignment method generates multiple sequence alignment fast but not necessarily with optimal costs. Dynamic programming generates multiple sequence alig~~menl with optimal costs in most cases but long execution time. In this paper. we suggest genetlc algorithm lo improve the multiple sequence alignment generated from the cnlent methods, describe the design of the genetic algorithm, and compare the multiple sequence alignments from 0111 method and current methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2A
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• pp.169-178
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• 2007

In this paper, we propose a signal structure and its optimum receiver to improve performance of SC-FDE(Single Carrier with Frequency Domain Equalization) system. Conventional SC-FDE systems have a drawback of power unbalance in frequency domain due to generation of pilot signals in time domain. The unbalanced power in frequency domain induces a channel estimation error and the performance of the receiver is degraded significantly. To overcome the drawback we apply CAZAC sequence which has constant power distribution in time and frequency domain. We design the signal structure to improve the performance with the repeated CAZAC sequence, and we design a receiver to optimize the proposed structure. Computer simulation results show that the proposed structure is superior to the conventional structure considering frame synchronization, frequency synchronization and channel equalization on typical wireless mobile channel environment.

• Composites Research
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• v.25 no.5
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• pp.141-146
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• 2012

The strength design for the lightweight bicycle wheel made of the Carbon/Epoxy composite laminates has been discussed in this paper. For bicycle wheel design, lightness of the wheel is important. Also, it has to satisfy the required strength under specific loading cases. Two testing methods for the bicycle wheel, i.e. vertical and complex loadings, are adopted in this study. Because the strengths of composite wheel is different in relation to the stacking sequence and the number of plies, it is important to decide an appropriate stacking sequence and number of layers for the composite wheel. From the finite element analysis results, the most stable sequence orientation and number of layers are determined. The stacking sequence $[0]_{8n}$, $[90]_{8n}$, $[0/90]_{2ns}$, $[{\pm}45]_{2ns}$, $[0/{\pm}45/90]_{ns}$ (n=1,2,3,4)are performed for finite element analysis. From results, $[0/{\pm}45/90]_{3s}$ lay-up is a good selection for the composite bicycle wheel. Also, the weakest point and layer are found in this study.