• Title/Summary/Keyword: small-scale data

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Displacement Ductility of Circular RC Column According to the Spacing of Spirals (나선철근 간격에 따른 원형 RC 기둥의 변위연성도)

  • Ko, Seong Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.2
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    • pp.71-82
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    • 2013
  • Eight small scale circular reinforced concrete columns (4.5 aspect ratio) were tested under cyclic lateral load with constant axial load. The selected test variables are longitudinal steel ratio (2.017%, 3.161%), transverse steel ratio, and axial load ratio (0, 0.07, 0.15). Volumetric ratio of spirals of all the columns is 0.335~0.894% in the plastic hinge region. It corresponds to 39.7~122.3% of the minimum requirement of confining steel by Korean Bridge Design Specifications, which represent existing columns not designed by the current seismic design specifications or designed by seismic concept. The final objectives of this study are to provide quantitative reference data and tendency for performance or damage assessment based on the performance levels such as cracking, yielding, steel fracture, etc. In this paper, describes mainly failure behavior, strength degradation behaviour, displacement ductility of circular reinforced concrete bridge columns with respect to test variables.

Policy Evaluation of the Government Financial Transfers to Korean Fisheries : LISREL Approach (수산부문 정부재정지원정책의 정성 평가)

  • 박성쾌;김정봉
    • The Journal of Fisheries Business Administration
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    • v.33 no.2
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    • pp.1-29
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    • 2002
  • The main objective of this research aims at analyzing efficiency of government financial transfers(GFTs) to the Korean fisheries sector, using the Linear Structural Relations model(i.e., LISERL model) and the field survey data. Most policies of GFTs tend to be implemented to protect industries with weak competitive advantages such as infant and/or primary industries. Specific policy instruments include income transfers, government loans with lower interest rates, taxes and the like. Fishing activities are made at a highly changeable natural environment of the ocean with a great amount of risk and uncertainty. Fishing households make their livelihood under the small-scale fisheries. Such fisheries and fishing households have also a relatively weak market power. Because of these fisheries characteristics most coastal states have adopted a variety of government support programs. However, despite such a huge government support, during the past several decades the world fishing communities have seen a tendency of continuous fishereis resource overexploitation. For this resason there have been hot debates over the government support policies for fisheries through OECD, FAO, WTO, and UNEP. In general, policy evaluations tend to be made on the basis of benefit-cost(B/C) analysis. However, the B/C analysis may produce results quite different from real ones primarily due to many unmeasurable effects. Thus, the authors composed simple questionaires and let fishermen, government officials and academic people answer the questions. The survery was made in several ways such as post-mail and personal/group interviews. In recent years, for analysis of policy performances and effectiveness, the LISREL model has often been used, which consists of structural and measurement eqquations. This model has a good advantage of transforming unobservable variables to observable ones so that it helps construct endogenous cause and effect relationships among relevant variables. The evaluation was done from the two aspects: policy results and policy effectiveness. The policy result evaluation showed that there is a need for improvement for policy problem perception and decision-making process, while the policy effect evaluation suggested that the policy goals were successfully achieved and social justice was improved from the perspective of the entire society as well. However, the research results showed that the GFT policies rendered little contrubtion to narrowing down the gap between GFT beneficiaries and non-beneficiaries incomes.

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Strengthening Performance of RC Beams Exposed to Freezing and Thawing Cycles after Strengthening in Shear with CFRP Sheet (CFRP 쉬트로 전단보강후 동결융해에 노출된 철근콘크리트 보의 보강성능)

  • Yun, Hyun-Do;Kim, Sun-Woo;Kim, Yun-Su;Lee, Min-Jung;Seo, Soo-Yeon;Choi, Ki-Bong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.161-164
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    • 2008
  • In recent years, carbon fiber-reinforced polymer (CFRP) has been widely used for repairing and/or strengthening structural elements in concrete. Not enough test data, however, are available to predict the long-term performance of the repaired and improved structures exposed to weathering. The objective of this research is to study the effect of freeze-thaw cycling on the behavior of reinforced concrete (RC) beams strengthened in shear with carbon fiber sheet. Six small-scale RC beams (100mm${\times]$100mm${\times]$400mm) were strengthened with CFRP in shear, subjected to up to 400 cycles freeze-thawing from -17${\sim}4^{\circ}C$, and tested to failure in four-point bending. Test result, there was no significant damage to carbon fiber sheet strengthened concrete beams had been suffered 30 cycles of freeze-thawing, and more over 60 cycles of freezing-thawing brought about a reduction in resistance of only 25% of the initial level.

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Impact of Tourism Development on the Regional Economy : Adopting the Tourist Money Flow Analysis (관광개발의 지역경제 파급효과: $\mathbb{\ulcorner}$관광지출흐름분석$\mathbb{\lrcorner}$ 방법론의 모색)

  • 주성재
    • Journal of the Economic Geographical Society of Korea
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    • v.1 no.1
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    • pp.113-135
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    • 1998
  • There have been several research methodologies to measure the impacts of tourism development on the regional economy, which include input-output analysis, income multiplier analysis, labor creation effect analysis, etc. Most of these are based on regional economic indices using secondary data for medium to large regional units. This study tests the possibility of adopting tourist money now analysis, which encompasses a series of money flows beginning with tourists'payment for room, board and shopping, followed by tourist companies'expenditure for material and service purchase, wage, utilities, rent, tax and so forth, and by tourism workers'expenses for living and savings. This method makes it possible to reveal the amount and geographical extent of tourist money flow and draws some meaningful regional economic figures. Case studies of three torist developing areas show that it is utilized for impact studies for small scale areas.

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Flow Stress Properties of Electric Resistance Welded Small-Sized Subsea Pipeline Subjected to Temperature and Strain Rate Variations (심해저용 전기 저항 용접 소구경 송유관 소재의 온도 및 변형률 속도 에 따른 유동 응력 특성)

  • Kim, Younghun;Park, Sung-Ju;Yoon, Sung-Won;Choung, Joonmo
    • Journal of Ocean Engineering and Technology
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    • v.29 no.3
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    • pp.241-248
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    • 2015
  • A subsea pipeline for oil/gas transportation or gas injection is subjected to extreme variations in internal pressure and temperature, which can involve a strain rate effect on the pipeline material. This paper describes the flow stress characteristics of a pipeline material called API 5L X52N PSL2, using and experimental approach. High-speed tensile tests were carried out for two metal samples taken from the base and weld parts. The target temperature was 100℃, but two other temperature levels of –20℃and 0℃ were taken into account. Three strain rates were also considered for each temperature level: quasi static, 1/s, and 10/s. Flow stress data were proposed for each temperature level according to these strain rates. The dynamic hardening behaviors of the base and weld metals appeared to be nonlinear on the log-scale strain rate axis. A very high material constant value was required for the Cowper-Symonds constitutive equation to support the experimental results.

An Analysis on the Actual Condition of Indoor Air Quality in Rural House (농촌지역 노후주택의 실내공기환경 실태분석 연구)

  • Park, Roun;Cho, Sukyeong;Kim, Sangbum
    • Journal of the Korean Institute of Rural Architecture
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    • v.22 no.2
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    • pp.9-17
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    • 2020
  • The ratio of the deterioration housing in rural area was 29.6%, but it was 18.3% in urban area based on a 2018 survey. In consideration of the point, this study aims to analyze the actual condition of indoor air quality in rural houses to provide basic data for improving the indoor air environment. It was investigated 15housings of Hongseong-gun, Chungchengnam-do. To investigate the correlation between indoor air quality and housing type, both the field survey of housing type and precision diagnosis of concentration of indoor air pollutants such as HCHO, TVOC, Fine dust(PM-10, PM-2.5), CO2, Radon. The results of this study are as follows. First, according to the average value of each element of rural old housing, the construction year was distributed in 1939~2004, and 12households(80%) living in houses older than 30years have passed for about 46years. As for the housing area, more than 12houses(80%) of 60㎡ or more and 3 houses (20%) of less than 60㎡ were often living in relatively small-scale housing. Second, as a result of measuring indoor air pollutants in rural houses, substances exceeding the standard values were found in HCHO, TVOC, CO2. Third, in the case of Fine dust and Radon, none of such factors were exceeded the standard. Fourth, there was no significant difference in indoor air quality depending on housing type in rural houses. This paper is expected to contribute to the regional development projects and effective implementation of rural policies.

Gray-level Image Watermarking using Wavelet Transform (웨이브렛 변환을 이용한 그레이-레벨 영상 워터마킹)

  • Min, Sun-Jin;Chung, Hoon;Kim, Chung-Hwa
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2001.10a
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    • pp.487-490
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    • 2001
  • With the establishment of the optimized copyright, digital image watermarking technique is demended to identify the owner of a certain image and to avoid the unauthorized distribution of digital image copies. Also, a robust watermarking approach should survive several possible attacks, such as image processing and lossy image compession. The proposed scheme distributes the 256 gray-level signature information in discrete wavelet transform domain of the host image where is very little visible distortion. While much of the privious work used signature data that is a small fraction of th e host images the proposed approach can easily handle gray-scale Images. As the result, stable reconstruction can be obtained even when the images are transformed, JPEG lossy compression or otherwise modified by low-pass filtering operations.

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Development of Escape and Rescue Path-taking Method for Plant Accident Response Training (플랜트 사고 대응 훈련을 위한 탈출 및 조치 경로 설계 기법 개발)

  • Kim, Hyoung Jean;Park, Chan-Cook;Lee, Jae Yong;Lee, Chun Sik
    • Journal of the Korean Institute of Gas
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    • v.21 no.6
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    • pp.61-69
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    • 2017
  • In case of plant accident, the most important measures that field operators, control-room operators and fire fighters must take are the escape from and going into the accident sites. These two different actions are reverse directional moving actions. By training operators and fire fighters with counter-accident path taking measurements, we can prevent the small accidents from becoming large-scale accidents, and can take efficient measurements in case of actual plant accidents. Out of necessities of path-taking training, in this research, we developed the escape and rescue path-taking method for plant accident response training. We can calculate the escape and rescue routes from a operator or fire fighter's current location as of accident happening and provide route data which in turn can be used as the safety training scenario. We expect this path-taking method can enhance the effectiveness and reality of escape and rescue training scenarios.

A Study on Architectural Planning Elements And Spatial Hierarchy of Kindergarten Attached to Elementary School - Focused on the Cases of Hwaseong, Gyeonggi Province - (초등학교 병설유치원의 건축계획요소 및 공간위계에 관한 연구 - 경기도 화성지역사례를 중심으로 -)

  • Kim, Hyoung-Soo;Park, Jae-Seung
    • Journal of the Korean Institute of Educational Facilities
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    • v.22 no.4
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    • pp.3-14
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    • 2015
  • This study analyzes the domestic kindergarten attached to elementary school, and that is to present the basic data to be established in the future on the basis of the problems seen in kindergarten attached to elementary school analysis of construction planning. For this study, selecting 10 kindergartens in Hwaseong, Gyeonggi-do, and the selected spatial configuration of kindergarten. And then, analyzes Space Organization, Circulation Plan, Area Distribution, Spatial Hierarchy of them. The results were as follows. 1) The current kindergarten attached to elementary school is associated with the most elementary building planes are independent. 2) Most of them don't have space for secondary activities such as playroom or hallway space between the classrooms and the entrance. 3) Interior space is composed of educational space, service space, administrative space. 4) Kindergarten attached to elementary school should plan increase the area because it is small scale there are a lot of dead space. 5) The main users of kindergarten children should be planned simultaneously in a space that is used along with the teacher. Such a kindergarten attached to elementary school in order to be implemented in construction and environmental characteristics of the kindergarten curriculum developers and juxtaposition of kindergarten teachers and architects such exchanges should be made a doctor of the tripartite briskly.

Current Challenges in Bacterial Transcriptomics

  • Cho, Suhyung;Cho, Yoobok;Lee, Sooin;Kim, Jayoung;Yum, Hyeji;Kim, Sun Chang;Cho, Byung-Kwan
    • Genomics & Informatics
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    • v.11 no.2
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    • pp.76-82
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    • 2013
  • Over the past decade or so, dramatic developments in our ability to experimentally determine the content and function of genomes have taken place. In particular, next-generation sequencing technologies are now inspiring a new understanding of bacterial transcriptomes on a global scale. In bacterial cells, whole-transcriptome studies have not received attention, owing to the general view that bacterial genomes are simple. However, several recent RNA sequencing results are revealing unexpected levels of complexity in bacterial transcriptomes, indicating that the transcribed regions of genomes are much larger and complex than previously anticipated. In particular, these data show a wide array of small RNAs, antisense RNAs, and alternative transcripts. Here, we review how current transcriptomics are now revolutionizing our understanding of the complexity and regulation of bacterial transcriptomes.