• 대한기계학회논문집A
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• 제20권6호
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• pp.1827-1835
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• 1996

This paper addresses the problem of a torch path generation for the 2D laser cutting of a stock plate nested with resular or irregular parts. Under the constaint of the relative positions of parts enforced by nesting, the developed torch path algorithm generate feasible cutting path. In this paper, the basic object is a polygon( a many-slide figure) with holes. A part may be represented as a number of line segments connected end-to-end in counterclockwise order, and formed a closed contour as requied for cutting paths. The objective is to tranverse this cutting contours with a minimum path length. This paper proposes a simulated annealing based dtorch path algorithm, that is an improved version of previously suggested TSP models. Since everypiercing point of parts is not fixed in advance, the algorithm solves as relazed optimization problem for the constraint, thich is one of the main features of the proposed algorithm. For aolving the torch path optimization problem, an efficient generation mechanism of neighborhood structure and as annealing shedule were introduced. In this way, a global solution can be obtained in a reasonable time. Seveeral examples are represented to ilustrate the method.

• 산업공학
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• 제20권2호
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• pp.121-132
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• 2007

The facility layout problem (FLP) involves the positioning of facilities within a given workplace in order to minimize the material flow distance between facilities. In this paper, we focus on the FLP in which the each facility has a rectangular shape and an input and output points. We develop a heuristic algorithm in which the facilities are arranged according to the layout algorithm using center of gravity and then simulated annealing algorithm is applied to improve the solution. A comparison of the computational results with exiting algorithms shows that the proposed algorithm provides better solutions in reasonable range of computational time.

• 한국통신학회논문지
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• 제16권12호
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• pp.1236-1248
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• 1991

행렬 분해방식에 의한 새로운 고속 DCT 연산 방법을 유도하였다. N점 DCT변환을 N/2점 DCT 변환과 2개의 N/4점 변환들로 얻을수 있었다. 이 방법은 곱셈작용이 대부분 신호 흐름도상의 출력단에 가깝게 있게 되어 유한길이 연산인 경우에 발생하는 반올림 오차량이 기존의 Lee와 Chen 방법에 비하여 배우 적다는 점이 장점이다. 그리고 곱셈작용의 위치는 다르지만 동일 연산량을 갖는 또다른 3개의 DCT 행렬분해 결과도 보였다.

• Kyungpook Mathematical Journal
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• 제49권4호
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• pp.701-712
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• 2009

In this paper, we first introduce a family S = {$S_n$ : C ${\rightarrow}$ C} of non-Lipschitzian mappings, called total asymptotically nonexpansive (briefly, TAN) on a nonempty closed convex subset C of a real Banach space X, and next give necessary and sufficient conditions for strong convergence of the sequence {$x_n$} defined recursively by the algorithm $x_{n+1}$ = $S_nx_n$, $n{\geq}1$, starting from an initial guess $x_1{\in}C$, to a common fixed point for such a continuous TAN family S in Banach spaces. Finally, some applications to a finite family of TAN self mappings are also added.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.238-241
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• 2000

This paper describes an equalizer using the DFE (Decision Feedback Equalizer) structure, CMA. (Constant Modulus Algorithm) and LMS (Least Mean Square) algorithms. We employ high speed multipliers, square logics and many CSAs (Carry Save Adder) for high speed operations. We have developed floating-point models and fixed-point models using the COSSAP$\^$TM/ CAD tool and developed VHDL models. We have peformed logic synthesis using the SYNOPSYS$\^$TM/ CAD tool and the SAMSUNG 0.5 $\mu\textrm{m}$ standard cell library (STD80). The total number of gates is about 130,000.

• 경영과학
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• 제26권1호
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• pp.197-208
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• 2009

In this paper, we study stochastic maximal covering location problem considering floating population. Traditional maximal covering location problem assumed that number of populations at demand point is already known and fixed. In this manner, someone who try to solve real world maximal covering location problem must consider administrative population as a population at demand point. But, after observing floating population, appliance of population in steady-state is more reasonable. In this paper, we suggest revised numerical model of maximal covering location problem. We suggest heuristic methodology to solve large scale problem by using genetic algorithm.

• 융합신호처리학회논문지
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• 제4권3호
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• pp.7-14
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• 2003

MPEG-1 오디오 표준은 고음질 디지털 오디오 신호의 압축 알고리즘이다. 이 표준은 인코더와 디코더의 기능을 규정하고 있고, 인코더와 디코더 알고리즘의 복잡도와 성능에 따라 세 가지 다른 계층으로 분류된다. 본 논문에서는 MPEG-1 오디오 계층3(MP3) 디코더를 고정소수점 DSP인 TMS320C541 칩으로 구현하였다 MP3 알고리즘은 인간의 청각구조의 심리음향 특성을 이용하는 알고리즘으로 인간의 귀에 들리지 않는 주파수의 성분은 미리 제거함으로써 데이터의 량을 줄이면서 음질의 손실을 최대한 줄이는 알고리즘이다. 이 알고리즘은 다이나믹 레인지가 매우 크기 때문에 고정 소수점으로 구현하기가 쉽지 않다. 본 연구에서는 가중 참조표를 적용하여 계산량을 줄이고 다이나믹 레인지 문제를 해결함으로써 고정 소수점 DSP칩을 이용하여 실시간 시스템을 구현하였다.

• Journal of applied mathematics & informatics
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• 제28권3_4호
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• pp.753-762
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• 2010

Let K be a nonempty closed convex subset of a real Hilbert space H. Let T : K $\rightarrow$ K be a nonexpansive mapping with a nonempty fixed point set Fix(T). Let f : K $\rightarrow$ K be a contraction mapping. Let {$\alpha_n$} and {$\beta_n$} be sequences in (0, 1) such that $\lim_{x{\rightarrow}0}{\alpha}_n=0$, (0.1) $\sum_{n=0}^{\infty}\;{\alpha}_n=+{\infty}$, (0.2) 0 < a ${\leq}\;{\beta}_n\;{\leq}$ b < 1 for all $n\;{\geq}\;0$. (0.3) Then it is proved that the modified Krasnoselski-Mann iterative sequence {$x_n$} given by {$x_0\;{\in}\;K$, $y_n\;=\;{\alpha}_{n}f(x_n)+(1-\alpha_n)x_n$, $n\;{\geq}\;0$, $x_{n+1}=(1-{\beta}_n)y_n+{\beta}_nTy_n$, $n\;{\geq}\;0$, (0.4) converges strongly to a point p $\in$ Fix(T} which satisfies the variational inequality

$\leq$ 0, z $\in$ Fix(T). (0.5) This result improves and extends the corresponding results of Yao et al[Y.Yao, H. Zhou, Y. C. Liou, Strong convergence of a modified Krasnoselski-Mann iterative algorithm for non-expansive mappings, J Appl Math Com-put (2009)29:383-389.

• 한국통신학회논문지
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• 제21권3호
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• pp.747-752
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• 1996

In this paper, we propose a new SO-MLSE(soft-output maximum likelihood sequence estimation) equalizer, which can be used in GSM digital cellular system) it uses complex correlation of training sequence to obtain the channel information and the equalization is performed by MLSE using Viterbi algorithm. In order to generate a soft-decision input to channel decoder (Viterbi decoder), the soft-output equalization algorithm is needed. The adopted algorithm doesn't require to modify the structure of HO-MLSE(hard output MLSE) equalizer, that is, SO-MLSE equalizer can be implemented by adding soft-output generation block to HO-MLSE equalizer. This algorithm uses the outputs of matched filter and HO-MLSE equalizer. It turns out that the complexity of proposed SO-MLSE equalizer is simpler than those of other SO-MLSE equalizer and its perforance is almost the same as those of others. Finally, the proposed SO-MLSE equalizer is also implemented s a prototype with ADSP-2101 16-bits fixed point digital signal processing chip.

• Journal of Electrical Engineering and information Science
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• 제2권6호
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• pp.191-196
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• 1997

Fuzzy clustering has been playing an important role in solving many problems. Fuzzy c-Means(FCM) algorithm is most frequently used for fuzzy clustering. But some fixed point of FCM algorithm, know as Tucker's counter example, is not a reasonable solution. Moreover, FCM algorithm is impossible to perform the on-line learning since it is basically a batch learning scheme. This paper presents unsupervised learning networks as an attempt to improve shortcomings of the conventional clustering algorithm. This model integrates optimization function of FCM algorithm into unsupervised learning networks. The learning rule of the proposed scheme is a result of formal derivation based on the gradient descent procedure of a fuzzy objective function. Using the result of formal derivation, two algorithms of fuzzy cluster analysis, the batch learning version and on-line learning version, are devised. They are tested on several data sets and compared with FCM. The experimental results show that the proposed algorithms find out the reasonable solution on Tucker's counter example.