• Computers and Concrete
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• 제22권3호
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• pp.305-317
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• 2018

Steel reinforced Engineered Cementitious Composite (ECC) components have been proposed for seismic structural applications, for example in coupling beams, infill panels, joints, columns, and flexural members. The development of strain in the steel reinforcement of cementitious components has been shown to vary based on both the steel reinforcement ratio and the applied deformation history. Strain in the steel reinforcement of reinforced ECC components is an important structural response metric because ultimate failure is often by fracture of the steel reinforcement. A recently proposed bond-slip model has been successfully calibrated to cyclically tested reinforced ECC beams wherein the deformation history contained monotonically increasing cycles. This paper reports simulations of two-dimensional finite element models of reinforced ECC beams to determine the appropriateness and significance of altering a phenomenological bond-slip model based on the applied deformation history. The numerical simulations with various values of post-peak bond-slip softening stiffness are compared to experimental results. Varying the post-peak bond-slip softening stiffness had little effect on the cracking patterns and hysteretic response of the reinforced ECC flexural models tested, which consisted of two different steel reinforcement ratios subjected to two different deformation histories. Varying the post-peak bond-slip softening stiffness did, however, affect the magnitude of strain and the length of reinforcing bar that strain-hardened. Overall, a numerical model with a constant bond-slip model represented well various responses in reinforced ECC beams with multiple steel reinforcement ratios subjected to different deformation histories.

• 대한전자공학회논문지TC
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• 제47권11호
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• pp.43-48
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• 2010

유전체 직각 릿지 표면 플라즈몬 도파로의 주요 파라미터인 모드 유효굴절률과 도파길이를 해석하였다. 여러 금속 및 유전체를 릿지의 폭과 두께를 변화시키며 유한요소법을 이용하여 계산하였다. 상반되는 두 파라미터를 포함하는 메트릭으로 2차원 figure of merit을 사용하였다. 계산결과를 이용하면 광통신 파장대역에서 파장이하로 모여 낮은 전파손실을 가진 도파로의 여러 파라미터 및 크기를 설계할 수 있다.

• 대한수학회보
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• 제48권5호
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• pp.991-1002
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• 2011

An iterative algorithm is provided to find a common element of the set of fixed points of a nonexpansive mapping and the set of solutions of some variational inequality in a Hilbert space. Using this result, we consider a strong convergence result for finding a common fixed point of a nonexpansive mapping and a strictly pseudocontractive mapping. Our results include the previous results as special cases and can be viewed as an improvement and refinement of the previously known results.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2006년도 춘계학술대회
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• pp.311-315
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• 2006

Viterbi decoder는 크게 BM(Branch metric), ACS(Add-Compare-Select), SM(Survivor Memory) block 으로 구성되어 있다. 이중 ACSU 부분은 고속 데이터 처리를 위한 bottleneck이 되어 왔으며, 이의 해결을 위한 많은 연구가 활발히 진행되어 왔다. look ahead technique은 ACSU를 M-step으로 처리하고 CS(Carry save) number를 사용한 새로운 비교 알고리즘을 제안하여 high throughput을 추구했으며, minimized method는 block processing 방식으로 forward, backward 방향으로 decoding을 수행하여 ACSU 부분의 feedback을 완전히 제거하여 exteremely high throughput 을 추구하고 있다. 이에 대해 look ahead technique 의 기본 PE(Processing Element)를 바탕으로 minimized method 알고 리즘의 core block 을 bit-level 로 구현하였으며 : code converter 를 이용하여 CS number 가운데 redundat number(l)를 제거하여 비교기를 더 간단히 하였다. SYNOPSYS의 Design compiler 와 TSMC 0.18 um library 를 이용하여 합성하였다.

• 디지털콘텐츠학회 논문지
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• 제12권3호
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• pp.339-345
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• 2011

군집화는 주어진 데이터를 분할하여 데이터 속에 숨겨져 있는 의미를 자동으로 발견하는 방법이다. k-means는 간단하고 빠른 군집화 알고리즘 중의 하나이다. 군집의 수 k는 군집화를 수행하는데 매우 중요한 요소이며, k의 값에 의해 군집화 결과가 달라진다. 본 논문에서는 반복적인 k-means 수행과 군집의 품질을 평가하는 외부 군집 연관 기준 정보를 결합하여 최적의 군집수를 결정하는 방법을 제안한다. 실험 결과 기존의 방법들에 비하여 제안하는 방법이 군집수의 정확성 측면에서 우수한 성능을 보였다.

• Nonlinear Functional Analysis and Applications
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• 제28권3호
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• pp.831-850
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• 2023

Our long-standing Metatheorem in Ordered Fixed Point Theory is applied to some well-known order theoretic fixed point theorems. In the first half of this article, we introduce extended versions of the Zermelo fixed point theorem, Zorn's lemma, and the Caristi fixed point theorem based on the Brøndsted-Jachymski principle and our 2023 Metatheorem. We show some of their applications to other fixed point theorems or theorems on the existence of maximal elements in partially ordered sets. In the second half, we collect and improve order theoretic fixed point theorems in the collection of Howard-Rubin in 1991 and others. In fact, we improve or extend several ordering principles or fixed point theorems due to Brézis-Browder, Brøndsted, Knaster-Tarski, Tarski-Kantorovitch, Turinici, Granas-Horvath, Jachymski, and others.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.18-26
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• 2010

도시공간의 안정과 쾌적함을 위하여 옥외조명은 우리 사회에서 필수적인 부분이 되었다. 그러나 옥외조명을 잘못 설치할 경우 조명에너지의 낭비뿐만 아니라 건축물 야간경관 훼손을 야기시킨다. 최근 야간 경관조명의 중요성이 부각되면서 지자체마다 야간경관 이미지 구축에 집중을 하고 있다. 그 중 해안가 주변의 옥외조명은 지역 내에 특화된 관광 상권을 구성하며 생동감 있는 도시 이미지를 부여하고 도시경쟁력을 강화 시킬 수 있다. 본 연구는 우리나라의 대표적 항구 도시인 부산의 해안가의 야간경관조명의 빛공해를 평가하는데 그 목적이 있다. 디지털 광학 계측기인 Radiant Imaging ProMetric-1400으로 광안리 해수욕장, 마린시티, 그리고 해운대 해수욕장 주변의 옥외조명을 측정하였다. 모든 옥외조명의 휘도는 국제조명위원회 권고기준과 비교했을 때 약 2~20배 정도 높게 나타났다. 주상복합 상부조명 및 해안에 면한 상가 저층부는 색채 및 휘도의 제한이 필요한 것으로 사료된다.

• ETRI Journal
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• 제31권5호
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• pp.545-553
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• 2009

String matching is a fundamental element of an important category of modern packet processing applications which involve scanning the content flowing through a network for thousands of strings at the line rate. To keep pace with high network speeds, specialized hardware-based solutions are needed which should be efficient enough to maintain scalability in terms of speed and the number of strings. In this paper, a novel architecture based upon a recently proposed data structure called the Bloomier filter is proposed which can successfully support scalability. The Bloomier filter is a compact data structure for encoding arbitrary functions, and it supports approximate evaluation queries. By eliminating the Bloomier filter's false positives in a space efficient way, a simple yet powerful exact string matching architecture is proposed that can handle several thousand strings at high rates and is amenable to on-chip realization. The proposed scheme is implemented in reconfigurable hardware and we compare it with existing solutions. The results show that the proposed approach achieves better performance compared to other existing architectures measured in terms of throughput per logic cells per character as a metric.

• 대한기계학회논문집A
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• 제24권1호
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• pp.190-195
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• 2000

It has been established that a crack has an important effect on the dynamic behavior of a structure. This effect depends mainly on the location and depth of the crack. To identify the location and depth of a crack in a structure. Nikolakopoulos et. al. used the intersection point of the superposed contours that correspond to the eigenfrequency caused by the crack presence. However the intersecting point of the superposed contours is not only difficult to find but also incorrect to calculate. A method is presented in this paper which uses optimization technique for the location and depth of the crack. The basic idea is to find parameters which use the structural eigenfrequencies on crack depth and location and optimization algorithm. With finite element model of the structure to calculate eigenfrequencies, it is possible to formulate the inverse problem in optimization format. Method of optimization is augmented lagrange multiplier method and search direction method is BFGS variable metric method and one dimensional search method is polynomial interpolation.

• 한국토양비료학회지
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• 제9권3호
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• pp.133-147
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• 1976

1. The purpose of this study is to provide a series of statistical "bench marks" from which one can begin to think systematically about the required development of the Korean food and fertilizer needs over the next quarter-century. 2. The Korean population has been estimated by the characteristics of the population and its social and political situations today. Because fertility and mortality rates are relatively stable and are under control of politics concerned, the estimation rates were established with 1.6% over 1975-1980, 1.3% over 1981-1990, and 1.0% over 1991-2000. 3. Annual per capita absorption of milled rice has fluctuated rather closely around 140kg, since 1968, with no evidence of declining trend. Per capita absorption of barley and wheat around 120 kg, and legumes around 10.6kg, However because the case of wheat and corn productions are rather difficult the self-sufficiency in the future, the rice is considered to be accelerate its yield growth surplus the level of self-sufficiency to export. 4. The fertilizer demand in each element has been calculated by mechanical multiplication of "the recommend index of fetilizer application" to yield a unit production over the need of national food supply by crop year. 5. As a results refer to Table (8), the estimated quantities of total fertilizer demand to meet the national food supply of the years of 1974, 1980, 1985, 1.990, 1995, and 2000 are reached around 871500, 1138150, 1375480, 1515030, 1652090 and 1799850 metric tons in each year.