• Geomechanics and Engineering
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• 제19권3호
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• pp.241-254
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• 2019

A finite element approach is presented to examine ground vibration characteristics under various moving loads in a homogeneous half-space. Four loading modes including single load, double load, four-load, and twenty-load were simulated in a finite element analysis to observe their influence on ground vibrations. Four load moving speeds of 60, 80, 100, and 120 m/s were adopted to investigate the influence of train speed to the ground vibrations. The results demonstrated that the loading mode in a finite element analysis is reliable for train-induced vibration simulations. Additionally, a three-dimensional finite element model (3D FEM) was developed to investigate the dynamic responses of a track-ballast-embankment-ground system subjected to moving loads induced by high-speed trains. Results showed that vibration attenuations and breaks exist in the simulated wave fronts transiting through different medium materials. These tendencies are a result of the difference in the Rayleigh wave speeds of the medium materials relative to the speed of the moving train. The vibration waves induced by train loading were greatly influenced by the weakening effect of sloping surfaces on the ballast and embankment. Moreover, these tendencies were significant when the vibration waves are at medium and high frequency levels. The vibration waves reflected by the sloping surface were trapped and dissipated within the track-ballast-embankment-ground system. Thus, the vibration amplitude outside the embankment was significantly reduced.

• Wind and Structures
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• 제32권2호
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• pp.89-104
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• 2021

Non-synoptic winds generated by tornadoes, downbursts or gust fronts exhibit significant non-stationarity and can cause significant wind load effect on flexible structures such as long-span bridges. However, conventional assumptions on stationarity used to evaluate the structural wind-induced vibration are inadequate. In this paper, an efficient frequency domain scheme based on fast CQC method, which can predict non-stationary buffeting random responses of long-span bridges, is presented, and then this approach is applied to evaluate the buffeting response of a long-span suspension bridge located in a complex mountainous wind environment as an example. In this study, the data-driven method based on one available measured wind speed sample is firstly presented to establish non-stationary wind models, including time-varying mean wind speed, time-varying intensity envelope function and uniformly modulated fluctuating spectrum. Then, a linear time-variant (LTV) system based on the proposed scheme can be generally applied to calculate the non-stationary buffeting responses. The effectiveness and accuracy of the proposed scheme are verified through Monte Carlo time domain simulation implemented in ANSYS platform. Also, the transient effect nature of the bridge responses is further illustrated by comparison of the non-stationary, quasistationary and steady-state cases. Finally, buffeting response analysis with traditional stationary treatment (10 min constant mean plus stationary wind fluctuation) is performed to illustrate the importance of the non-stationary characteristics embedded in original wind speed samples.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권9호
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• pp.2976-2990
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• 2022

The adaptive adjustment of reference or weight vectors in decomposition-based methods has been a hot research topic in the evolutionary community over the past few years. Although various methods have been proposed regarding this issue, most of them aim to diversify solutions in the objective space to cover the true Pareto fronts as much as possible. Different from them, this paper proposes a knee point-based reference vector adaptive adjustment strategy to concurrently balance the convergence and diversity. To be specific, the knee point-based reference vector adaptive adjustment strategy firstly utilizes knee points to construct the adaptive reference vectors. After that, a new fitness function is defined mathematically. Then, this paper further designs a many-objective evolutionary algorithm with knee point-based reference vector adaptive adjustment strategy, where the mating operation and environmental selection are designed accordingly. The proposed method is extensively tested on the WFG test suite with 8, 10 and 12 objectives and MPDMP with state-of-the-art optimizers. Extensive experimental results demonstrate the superiority of the proposed method over state-of-the-art optimizers and the practicability of the proposed method in tackling practical many-objective optimization problems.

• Acta Via Serica
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• 제7권2호
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• pp.65-88
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• 2022

With the expansion of the Russian Empire southward in the nineteenth century, connoisseurs, art historians, and scholars in Russia began to pay attention to carpet traditions in the new territories of the Russian Empire in Turkestan. In journals and other specialty publications, they underscored a need to establish claims to authority over the knowledge of the traditional craft. They were highly attuned to parallel accounts of carpet weaving from regions that had a longer history of research and collecting of carpets. In contrast to the situation in Western Europe or the United States, commentators bemoaned the fact that the public and even professed experts in Russia did not properly appreciate carpets from the Caucasus and Central Asia. These scholars articulated a need to establish authority over the carpet weaving traditions of Russia's colonial possessions, resulting in a push toward a serious study of carpet weaving as a legitimate field of inquiry. This paper uses published sources on early carpet scholarship from the late nineteenth and early twentieth centuries to examine how carpet weaving traditions in Central Asia entered an imperial discourse of knowledge. It argues that attempts to understand and categorize carpet weaving as an art form occurred along two fronts. Intellectuals and scholars attempted to wrest control over the locus of knowledge from experts in the West as well as from local weavers. In the process, they established a distinctly imperial vision of carpet weaving in contrast to competing imperial discourses and over traditional forms of knowledge.

• 한국지역지리학회지
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• 제9권2호
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• pp.192-202
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• 2003

본 연구는 한반도 전역에 걸쳐 장마전선의 위치에 따라 강수량의 분포특성을 살피고 이 강수량이 6, 7월 평균강 수량에 대한 기여율을 조사한 것이다. 그 결과 장마전선이 북위 30도 이북에 있는 경우 한반도 전체에서 전선과 가까운 지역에서 많은 강수량이 나타났으며 이들은 다우지역과 대체로 일치한다. 전선이 북위 30도 이남에 있는 경우와 비교하여 30${\sim}$33도로 북상할 때 전국적으로 강수량이 증가하여 이 시기에 장마가 시작됨을 알 수 있었다. 장마철에 개마고원 일대에서는 미우의 출현비율이 매우 높았다. 이중에는 장마전선과 무관한 강수도 상당수 있을 것으로 판단된다. 청천강 유역에서는 6, 7월 평균강수량에 대한 기여율이 큰 경우가 전선이 없을 때, 전선이 청천강 유역에서 먼 북위 30${\sim}$33도에 있는 때로서 한반도의 타 다우지역과는 다른 특성을 보인다.

• 수산해양기술연구
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• 제48권1호
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• pp.59-71
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• 2012

In order to elucidate the mechanism of fishing condition variation of anchovy in the set net fisheries of Anggang Bay, the monthly catch of anchovy was analyzed and examined based on the data acquired from 2006 to 2010 in 13 different fishing grounds. Anchovy consistently appeared from April to December and reached the production of 840 to 1,424 t (average : 1,228 t), with a big annual variation. However, anchovy production in this area accounts for approximately 75% of the production by set net in Anggang Bay whereas it holds 6.8% of the nationwide production (=18,034 t) by set net. The school of anchovy starts to appear in April at the west mouth of the bay and move north-eastward. Afterward, having three of clockwise turns in the middle of the bay, they scatter to swim into the deep place of the bay and finally go out to turn back to their coming way. These behaviors of anchovy are likely related to thermal fronts as well as distributions of food. The production of anchovy (y, kg) relied greatly on frequencies of effective northeasterly ($x_1$) or northwesterly ($x_2$) wind (${\leq}$3.5m/s) which blow between April and June. Their relationships are as follows: $y=1086.27+21.499x_1-15.16x_2$ (r=0.901). Consequently, we concluded that the northeasterly wind, which appears in the breeding season of spring, played a role to retard the movement of anchovy school to the eastern sea, while the northwesterly wind inhibits the invasion of anchovy school into the bay.

• 한국광학회지
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• 제14권4호
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• pp.392-398
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• 2003

구면 거울을 정밀하고 정확하게 측정할 수 있는 위상천이 회절격자 간섭계를 제시한다. 간섭계는 하나의 회절격자를 이용하여 간섭계의 기준광과 측정광을 분할하고, 다시 결합시켜 간섭무늬를 생성시키고 위상천이 시키는 간단한 구조로 설계되었다. 광원으로부터의 광을 큰 수치구경인 고정도의 집속렌즈의 초점에 위치한 회절격자 위에 집속하여 반사회절된 파면을 기준파면과 측정파면으로 사용한다 부가적인 기준면이 없이 회절격자 위의 매우 작은 영역이 기준면을 대신하므로 시스템 오차가 작다. 광섬유 형태의 공초점현미경 구조를 광원과 집속렌즈 사이에 설치하여 집속렌즈와 회절격자사이의 정렬오차를 최소화 하였다. 회절격자를 광축에 수직한 방향으로 이송함으로써 기준파면과 측정파면사이에 상대적인 위상천이를 일으켜서 일련의 위상천이된 간섭무늬를 쉽게 획득할 수 있다. 간섭계를 제작하고, 결상렌즈와 CCD를 이용해서 얻은 위상천이된 대상구면 거울의 간섭무늬들을 해석하여 전체적인 간섭계 시스템의 성능을 평가해 보았다.

• 마케팅과학연구
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• 제15권2호
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• pp.123-140
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• 2005

본 연구는 메가 이벤트 도입에 있어 지역주민들과의 갈등 원인과 거주민의 인구특성과의 관계 그리고 라이프스타일에 따른 주민들의 지각차이를 부정적 지각을 중심으로 도입저해 요인을 탐색하였다. 그 결과 자동차 경주 도입 거부요인으로 도시환경, 생활환경, 교육환경, 지역산업환경, 그리고 관광산업환경으로 나타났다. 이 중 교육환경과 도시환경이 가장 중요한 거부요인으로 밝혀졌다. 인구통계적 특성과 거주지 및 직장위치, 그리고 개인의 라이프스타일에 따라 자동차 경주 도입의 거부에 대한 지각이 다르게 나타났다. 또한 지역주민들이 우려하는 환경요인을 라이프스타일 유형에 따라 분석하여, 자아과다통제형, 자아탄력적통제형, 자아과소통제형에 따라 서로 상이한 지각이 행사됨을 밝혔다.

• 한국의류학회지
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• 제25권4호
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• pp.719-730
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• 2001

The purpose of this study is to develop the basic patterns of adult womens brassiere therewith, provide for some basic data useful to the brassiere manufacturing which are both functional and fitting. For this purpose, 220 adults women(aged between 20 and 59) were sampled to be measured for their body sizes and tested for their brassiere wearing. The collected data were statistically processed using the SAS 6.12 for Means, Standard Deviation, etc. The results of this study can be summarized as follows; 1. In order to develop the basic patterns of adult womens brassieres, 75A size was selected out of 12 size combination(3 women per 75A size) and then, their brassiere fitting was tested. As a result, the fronts of the basic patterns were found to have such problems as undone front center, poor levelling of upper cups bottom line or lower cups top line, poor shape of upper cups outside top line and shoulder strip position. On the other hand, n the rear side of the basic patterns, the central part of the wing was slightly lifted, while the wing width and straps interval did not befit the full-cup brassiere. The result of this first brassiere fitting test showed that the functionality and aesthetics of the basic pattern brassieres were more or less satisfactory, and thus, the problems were address for the second test. In the second test, the aesthetics, breast-shaping effect and functionality of the basic pattern brassieres were much improved. 2. The basic patterns of adult womens brassieres were characterized by a round cup wired as well as a full cup embracing the entire breasts. Each basic pattern which consisted of upper and lower cups was shaped \"straight(-)\". The basic sizes adopted at the first design stage (see fig. 1-2) was 75A of which was designed as upper foundation basic pattern. At the second stage, the upper body foundation pattern were used to design lower cup, upper cup, front panel and wing in their order.(see fig. 3-5, fig. 8)5, fig. 8)

• 한국수산과학회지
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• 제30권4호
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• pp.513-522
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• 1997

우리나라 주변 해역에서 어획되는 오징어 (Todarodes pacificus Steenstrup)의 주 대상 어업인 오징어채낚기어업의 어장 분포의 변화 및 수온전선대의 형성 양상과 어획량의 관계 등을 밝혔다. 한국 동해에서 오징어채낚기어업의 중심 어장은 4월에 북상하기 시작하여 8월부터 동해 중부에서 본격적인 어장이 형성되며, 울릉도 남쪽 해역에서 밀도 높은 어장이 형성되었다. 9월부터 남하하기 시작하나 어획량은 10월에 최고 값을 보였고 다음해 1월까지 어기가 지속된 후 2월부터 월동장으로 남하 회유하여 봄철에는 한어기를 맞이하였다. 동해의 주 조업 어장에서 형성되는 수온전선대의 형성양상과 오징어 어황과는 밀접한 관계가 있는 것으로 나타났다. 수온전선대가 주 조업 어장 내에서 동서 방향으로 형성되면 어군의 밀집이 이루어져 어황은 좋았고, 수온전선대가 연안을 따라 남북 방향으로 길게 형성되면 남한내 주 조업 어장에서는 어황이 좋지 않게 나타났다.