• 한국도로학회논문집
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• 제13권1호
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• pp.1-11
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• 2011

본 연구는 교량 중에 장대교량을 대표하는 현수교에 대한 설계 시 고려요소인 중앙경간과 새그비의 변화에 따른 경관선호도를 파악하고 경관선호도와 이미지요인과의 관계, 설계요소와 이미지요인과의 관계를 SD법을 적용하여 교량의 이미지 특성을 파악함으로써 경관적 환경을 조성할 수 있는 방안을 제시하는데 연구의 목적이 있다. 교량경관에 대한 경관적 선호도를 분석한 결과 교량의 중앙경간의 길이가 길어질수록 선호하는 새그비의 범위는 줄어드는 것으로 보아 중앙경간이 길어질수록 낮은 새그비를 선호하며, 중앙경간이 길어질수록 경관선호도가 높아짐을 알 수 있었다. 경관선호도와 이미지요인에서는 경관선호도가 높은 새그비의 속성에는 "안정성" "조형성" "심미성"과 모두(+)상관관계에 있지만 "조형성"의 영향이 미비하였다. 설계요소와 이미지 요인과의 관계에서는 중앙경간과 새그비의 요인에는 "안정성"이라는 요인과 더 관계되어 있었으며, 새그비가 낮아질수록 중앙경간이 길어질수록 "안정성"이 높게 평가되었다. 이 결과, 경관적으로 선호하는 이미지의 특성 중 "조형성"의 이미지 특성이 미비한 것으로 나타나 "조형성"의 이미지특성의 부각을 위해 중앙경간과 새그비의 비례요소가 아닌 균형과 대칭의 요소의 변화를 주어 보완실험을 하였다. 그 결과 3주탑현수교와 새그의 좌우대칭이 다른 현수교가 "조형성"의 이미지 특성이 더 부각되는 결과를 볼 수 있었고, 추후에 현수교의 경관설계를 할 때 비례요소뿐만 아니라 균형과 대칭의 요소도 고려하여 설계 시 반영하여야 할 것이다.

• 한국잠사곤충학회지
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• 제41권3호
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• pp.154-166
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• 1999

General characteristics and life span of silkworm moth were investigated amongst 277 gene resources preserved and maintained in Korea. Silkworm varieties were classified according to the commercial characteristics and the viability of tested varieties. There were significant differences among the eight different commercial characteristics of silkworm such as whole larval period, duration of 5th instar, pupal body weight, single cocoon weight, cocoon shell weight, cocoon shell ratio, cocoon yield and longevity, Tropical race showed the longest life span among the other five geographical races, and followed by Japanese, European, Chinese and Korean race in order. In the longevity of each variety, Daizo(sdi) showed the shortest life span with 4.3days, and J037 was the longest as 16.0 days. Average longevity of female was 11.1 days as showed 3.0 days longer than that of male which was 8.2 days. Total average longevity of the whole varieties was 9.7days. In the correlation between the longevity and commercial characteristics, there was a tendency that the commercial characteristics became better when the life span was longer. According to the result of Complete Linkage Cluster Analysis, the genetic resources of 277 silkworm varieties classified into 5 groups such as “Group I”for short life span with low cocoon yielding “Group II”for middle life span with middle cocoon yielding,“Group III”for the shortest life span with low cocoon yielding, “Group IV”for high pupation rate and the highest cocoon yielding with comparatively long life span, and “Group V”for the longest life span with comparatively high cocoon yielding.

• Structural Engineering and Mechanics
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• 제34권5호
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• pp.635-662
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• 2010

In this study, the effect of superstructure-abutment continuity on the distribution of live load effects among the girders of integral abutment bridges (IABs) is investigated. For this purpose, two and three dimensional finite element models of several single-span, symmetrical integral abutment and simply supported (jointed) bridges (SSBs) are built and analyzed. In the analyses, the effect of various superstructure properties such as span length, number of design lanes, girder size and spacing as well as slab thickness are considered. The results from the analyses of two and three dimensional finite element models are then used to calculate the live load distribution factors (LLDFs) for the girders of IABs and SSBs as a function of the above mentioned parameters. LLDFs for the girders are also calculated using the AASHTO formulae developed for SSBs. Comparison of the analyses results revealed that the superstructure-abutment continuity in IABs produces a better distribution of live load effects among the girders compared to SSBs. The continuity effects become more predominant for short span IABs. Furthermore, AASHTO live load distribution formulae developed for SSBs lead to conservative estimates of live load girder moments and shears for short-span IABs.

• 대한가정학회지
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• 제30권4호
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• pp.153-165
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• 1992

The objectives of this study were to develop a probabilistic model for both hypotheses testing and mobility prediction. Methodologies being used for the analysis include multivariated analysis for descriptive statistics and logit model for hypotheses testing and prediction. The study used questionaire survey data conducted by Korean Research Institute for Human Settlements (KRIHS) in 1988. There were a total of 1,620 Samples, and both SPSS and Limdep software packages were used for statistical analysis and model testing. The major findings were highlighted as follows; The residential mobility over family life span by the social class were developed with the use of the probability model. Most of households in low class moved downwardly. They had lived the small-owned single detached house in first family life span and moved into the small-rented single detached house in next family life span. Most of households in middle class moved upwardly. They had lived the small-owned apartment in first family life span and moved into the large-owned single detached house in last family life span. Most of households in high class horizontally. They had lived the large-owned single detached house in first family life span and moved into the same one except in last family life span.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.594-597
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• 2012

전체 전송로 중간에 광 위상 공액기 (OPC; optical phase conjugator)를 둔 광전송 링크에서 파장 분할 다중 (WDM; wavelength division multiplexed) 송신기부터 OPC까지의 전반 전송 구획과 OPC부터 WDM 수신부까지의 후반 전송 구획 각각을 구성하는 단일 모드 광섬유 (SMF; single mode fiber)의 중계 구간 (span)들 중 단지 하나의 중계 구간에서만 RDPS(residual dispersion per span)만 갖고 나머지 중계 구간에서는 RDPS가 0 ps/nm로 설계된 전송 링크에서 WDM 신호를 최상의 성능으로 전송하기 위한 최적의 링크 구조를 도출하였다.

• 대한인간공학회지
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• 제26권3호
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• pp.59-65
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• 2007

In this study, six grip spans (45mm-65mm) were tested to evaluate the effects of handle grip span and user's hand size on maximum grip strength, individual finger force, and subjective ratings of comfort using a digital dynamometer with individual force sensors. Forty-six males were assigned into three hand size groups according to their hand lengths. Results showed that overall 55mm and 50mm grip spans were the most comfortable sizes and associated with the highest grip strength in the maximum grip force exertions, whereas 65mm grip span was rated as the least comfortable size as well as the lowest grip strength. In the interaction effect of grip span and hand size, small and middle hand sized participants rated the best preference and the least preference grip spans differently with large hand sized participants. With respect to the analysis of individual finger force, the middle finger force was the strongest and the highest contribution to the total finger force, followed by ring, index and little fingers. In addition, it was noted that each finger had a different optimal grip span for exerting maximum force resulting in a bowed contoured shaped handle for two-handle hand tools. Thus, the grip spans for two-handle hand tools might be designed according to the users' hand and finger anthropometrics to maximize performance and subjective perception of comfort.

• Earthquakes and Structures
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• 제8권4호
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• pp.859-887
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• 2015

Structural health monitoring (SHM) has gained in popularity in recent years since it can assess the performance and condition of instrumented structures in real time and provide valuable information to the asset's manager and owner. Operational modal analysis plays an important role in SHM and it involves the determination of natural frequencies, damping ratios and mode shapes of a constructed structure based on measured dynamic data. This paper presents the operational modal analysis and seismic response characterization of the Tsing Ma Suspension Bridge of 2,160 m long subjected to different earthquake events. Three kinds of events, i.e., short-distance, middle-distance and long-distance earthquakes are taken into account. A fast Bayesian modal identification method is used to carry out the operational modal analysis. The modal properties of the bridge are identified and compared by use of the field monitoring data acquired before and after the earthquake for each type of the events. Research emphasis is given on identifying the predominant modes of the seismic responses in the deck during short-distance, middle-distance and long-distance earthquakes, respectively, and characterizing the response pattern of various structural portions (deck, towers, main cables, etc.) under different types of earthquakes. Since the bridge is over 2,000 m long, the seismic wave would arrive at the tower/anchorage basements of the two side spans at different time instants. The behaviors of structural dynamic responses on the Tsing Yi side span and on the Ma Wan side span under each type of the earthquake events are compared. The results obtained from this study would be beneficial to the seismic design of future long-span bridges to be built around Hong Kong (e.g., the Hong Kong-Zhuhai-Macau Bridge).

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.629-634
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• 2000

In this study, 9 reinforced concrete(RC) continuous beams were tested to investigate the arch action. By measuring longitudinal steel strains during the whole loading stages up to failure, the development of arch action is evaluated. Variables included are span length, longitudinal steel ratio and the presence of stirrups. As a result, it was known that measured steel tension in the span is substantially higher than the conventionally calculated values, and it was appeared that near the middle of the shear span the measured values exceeded the calculated values by factors of up to 1.4 or more.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.530-537
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• 2006

Recently, the railroad route plan is trying to minimize the damage of the local resident which is caused by railroad construction. For this reason, reducing the banking height of soil roadbed, lowering the bridge girder height of a solid intersection and a part of cross river, the through bridge type which can achieve a required span length must apply. The representative through bridges of railroad are arch bridges, truss bridges and plate girder bridges, the through plate girder bridge of variable section can apply that the span length of these bridges is about $30{\sim}50m$, namely, middle span length bridge types, and that can satisfy structural capacity and beauty of railroad at the same time. This paper introduces plan and design process of the Su-eo cheon bridge applied by a through plate girder bridge type of the Jinju-Gwangyang double track 6th construction ordered at Korea Rail network Authority in 2005.

• Journal of information and communication convergence engineering
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• 제20권4호
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• pp.235-241
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• 2022

A dispersion map was proposed to improve the compensation effect of a distorted WDM (wavelength division multiplexed) channel in a dispersion-managed link coupled with optical phase conjugation. The dispersion map is an origin-symmetric structure around the optical phase conjugator in the middle of the transmission path. In addition, the dispersion map has a form in which a constant dispersion accumulation pattern is repeated regularly. Through simulation, we confirmed that the application of the origin-symmetric dispersion map with a repetitively shaped configuration was more effective in compensating for the distorted WDM channel than in the dispersion-managed link with a conventional dispersion map. In addition, we confirmed that the compensation effect could be increased when the cumulative dispersion distribution of the origin-symmetric distribution map had a positive value in the first half section and a negative value in the second half section. Further, we observed that as the number of repeated dispersion accumulation patterns increased, the residual dispersion per span should also be increased.