• Title/Summary/Keyword: ties

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Enhancing the Performance of High-Strength Concrete Corbels Using Hybrid Reinforcing Technique (하이브리드 보강기법을 활용한 고강도 콘크리트 내민받침의 성능 향상)

  • Yang, Jun-Mo;Lee, Joo-Ha;Min, Kyung-Hwan;Yoon, Young-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.13-16
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    • 2008
  • Corbels are short cantilevers that project from the faces of a column and are a type of stress disturbed member, resisting both the ultimate shear force applied to them by the beam, and the ultimate horizontal force caused by shrinkage, temperature changes, and creep of the supported elements. Recently, as there have been an increase in the use of high-strength concrete and the concern about corrosion problems, lots of researches about hybrid reinforcing technique, applying strategically high performance reinforcements to the concrete elements, are performed. In this study, fiber reinforced high strength concrete corbels were constructed and tested for applying hybrid reinforcing technique to the corbels using steel fibers and headed bars. The results showed that the performance in terms of load carrying capacities, stiffness, ductility, and crack width was improved, as the steel fibers were added and the percentage of steel fibers was increased. In addition, the corbel specimens used headed bars as main tension ties showed superior load carrying capacities, stiffness, and ductility to the corbel specimens anchored main tension ties by welding to the transverse bars.

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Distribution of Inter-Contact Time: An Analysis-Based on Social Relationships

  • Wei, Kaimin;Duan, Renyong;Shi, Guangzhou;Xu, Ke
    • Journal of Communications and Networks
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    • v.15 no.5
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    • pp.504-513
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    • 2013
  • Communication in delay tolerant networks (DTNs) relies on message transport by mobile nodes, and a correct understanding of the node mobility characteristics is therefore crucial to the design of an efficient DTN routing protocol. However, previous work has mainly focused on uncovering all behaviors of node movement, which is not conducive to accurately detecting the specific movement characteristics of a different node. In this paper, we seek to address this problem based on a consideration of social relationships. We first consider social ties from both static and dynamic perspectives. For a static perspective, in addition to certain accidental events, social relations are considered for a long time granularity and tend to be stable over time. For a dynamic perspective, social relations are analyzed in a relatively short time granularity and are likely to change over time. Based on these perspectives, we adopted different efficient approaches to dividing node pairs into two classes, i.e., familiar and unfamiliar pairs. A threshold approach is used for static social ties whereas a density-based aggregation method is used for dynamic social relationships. Extensive experimental results show that both familiar and unfamiliar node pairs have the same inter-contact time distribution, which closely follows a power-law decay up to a certain point, beyond which it begins to exponentially decay. The results also demonstrate that the inter-contact time distribution of familiar pairs decays faster than that of unfamiliar pairs, whether from a static or dynamic perspective. In addition, we also analyze the reason for the difference between the inter-contact time distributions of both unfamiliar and familiar pairs.

Design of Boundary Confinement of Structural Walls (구조벽의 단부 횡보강 설계)

  • Kang, Su-Min;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.15 no.6
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    • pp.877-887
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    • 2003
  • For a performance-based design of structural walls, it is necessary to develop a rational design method for determining the length and detail of boundary confinement so as to satisfy the given ductility demand. In the present study, the curvature capacity of a structural wall with boundary confinement was estimated considering the effects of various design parameters. The curvature demand of the plastic hinge corresponding to the given design displacement was also determined. By equalizing the curvature capacity to the demand, a design method for determining the length of boundary confinement, was developed. According to the design method, the length of boundary confinement increases as axial compressive load and design displacement increase, and as concrete strength, wall thickness, amount of lateral reinforcement and aspect ratio decrease. A study was performed on details for effective lateral confinement of walls with rectangular cross-section. Based on the findings, design guidelines on spacings of ties and cross-ties were proposed.

Fermented Whey Produced by Mixed Culture of Lactobacillus acidophilus and Propionibacterium freudenreichii : Effect on Quality Properties of Bread (Lactobacillus acidophilus와 Propionibacterium freudenreichii로 혼합 배양한 Whey 발효물이 빵의 특성에 미치는 영향)

  • Yun Mi-Suk
    • The Korean Journal of Food And Nutrition
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    • v.18 no.2
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    • pp.109-114
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    • 2005
  • A mixed Lactobacillus acidophilus and Propionibacterium freudenreichii was cultured in the $10\%$ whey broth with $0.5\%$ yeast extract for 4 days. Viable cell numbers of Lactobacillus acidophilus and Propionibacterium freudenreichii were $2.4\ties10^9$ cfu/mL after 36hr and $9.42\times10^8$ cfu/mL after 96 hr. Consumption rate of lactose during fermentation was $87.5\%$. Propionic acid was produced 18.5g/L and acetic acid was produced 4.8g/L, as a result of that, comparison of propionic acid and acetic acid was 3.8:1 Volume of white pan bread was decreased as added amount of whey was increased. Hardess of white pan bread was decresed as added amount of whey was increased. Preservation period of white pan bread with $10\%$ whey fermented product elongated 2 day compared to control.

Film Storytelling through Family Films of Korea and America (가족 영화로 본 한국과 미국의 영화 스토리텔링)

  • Yook, Sang-Hyo
    • The Journal of the Korea Contents Association
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    • v.13 no.10
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    • pp.151-159
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    • 2013
  • Formalism narrative theory adopts the dualism of Fabula, story material and Sujet, story substance. The recent theories of storytelling convert the dualism into story and storytelling. This essay delves into the mechanism of contemporary storytelling by comparatively analyzing the storytelling of two films, A Korean film, Family Ties and A Hollywood film, Little Miss Sunshine, which are considered to represent contemporary storytelling. While the latter builds its structure through desire usually shown in the classical Hollywood films, the former has the structure which has nothing to do with causality by displaying fragmented stories. And the latter has typical characters, while the former shows totally different reality, using the obscure characters. In conclusion, Little Miss Sunshine has a storytelling which puts audience feeling in tune by controlling it, and Family Ties has one which delivers director's intention.

Use of Near Infrared Spectroscopy in the Meat Industry

  • Akselsen, Thorvald M.
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2000.11a
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    • pp.1-14
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    • 2000
  • The Near Infrared region of the energy spectrum was first discovered by Hershel in the year 1800. The principles of NIR is based on light absorption of specific organic chemical bonds. The absorption at each wavelength is measured and a spectre is obtained. The spectre is then treated mathematically and with the absorption data is converted to absolute units via a calibration. In the last two decades it has developed dramatically. With the invention of computers and the ability to treat a large amount of data in a very short time the use of NIR for many different purposes has developed very fast. During the last decade with the aid of very powerful PC's the application of NIR technology has become even more widespread. Now or days development of very robust calibrations can be done in a relatively short time with a minimum of resources. The use of Near Infrared Spectroscopy (NIR) in the Meat industry is relatively new. The first installations were taken into operation in the 80ties. The Meat Industry in often referred to as rather conservative and slow to embrace new technologies, they stay with the old and proven methods. The first NIR instruments used by the Meat Industry, and most other industries, were multipurpose build, which means that the sample presentation was not well suited to this particular application, or many other applications for that sake. As the Meat Industry grows and develops to meet the demands of the modern markets, they realise the need for better control of processes and final products. From the early 90 ties and onward the demand for 'rear time' rapid results starts growing, and some suppliers of NIR instruments (and instruments based on other technologies, like X-ray) start to develop and manufacture instrumentation dedicated to the particular needs of the Meat Industry. Today it is estimated that there are approximately 2000 rapid instruments placed in the Meat industry world-wide. By far most of these are used as at-line or laboratory installations, but the trend and need is moving towards real on-line or in-line solutions. NIR is the most cost effective and reproducible analytical procedure available for the twenty first century.

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Seismic Performance of Octagonal Flared RC Columns using Oblong Hoops (장방형 띠철근을 이용한 팔각형 플레어 RC 기둥의 내진성능)

  • Ko, Seong-Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.19 no.6
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    • pp.1-9
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    • 2015
  • Transverse steel bars are used in the plastic hinge zone of columns to insure adequate confinement, prevention of longitudinal bar buckling and ductile behavior. Fabrication and placement of rectangular hoops and cross-ties in columns are difficult to construct. Details of reinforcement for rectangular section require a lot of rectangular hoops and cross-ties. In this paper, to solve these problems, the new lateral confinement method using oblong hoop is proposed for the transverse confinement of the flared column. It can be the alternative for oblong cross-section and flared column with improved workability and cost-efficiency. The final objectives of this study are to suggest appropriate oblong hoop details and to provide quantitative reference data and tendency for seismic performance or damage assessment based on the drift levels such as residual deformation, elastic strain energy. This paper describes factors of seismic performance such as ultimate displacement/drift ratio, displacement ductility, response modification factor, equivalent viscous damping ratio and effective stiffness.

A Study on the Characteristics of the Library Space for Introducing Urban Experiences (이용자의 도시적 공간체험을 유도하는 도서관 공간 특성 연구)

  • Moon, Eun-Mi
    • Korean Institute of Interior Design Journal
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    • v.23 no.4
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    • pp.240-247
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    • 2014
  • This study is aimed to examine the characteristics of library space, in which user experiences and social networking are central in its design. Today, a library is a place to provide diverse accesses and experiences to information networks, where various individuals and user groups come and share mutual understanding and experiences. Library users developed social ties and a sense of community through library experiences. As a multipurpose space of a community, a library has the characteristics of urban public space like sidewalks and plazas. The eight case studies of libraries are analyzed from the viewpoint of each factor of library experience, including landscape, sidewalk, and plaza experience. The study drew its conclusions as follows. First, a library is a regional landmark for the users. Thus, it tends to be designed to allow transparency on its surface which introduces inner and outer landscape into the inside of the building. Second, the users experience a library similarly as they experience an urban street where they interface, browse, and interact with people and information. As they interact and share experiences, they develop solidarity and social ties among them. A library is designed to preserve continuity to adjacent streets, which increases accessibility to the building and hosts street activities into the building. Third, a library today is designed to be a flexible open space with information networking as well as community networking which allows library users diverse activities within it. For example, a multipurpose grand stairs in the middle of the main circulation of a building allows the users diverse activities. A large open stack with reading areas gives the users the feeling of an urban plaza where they can move vertically and horizontally. In conclusion, all findings of this study imply a user-oriented design for a library building.

Communication Network Analysis of General Corporate IT Staff : A Case Study of Company "K" (일반기업의 IT조직 내 직원간 의사소통 네트워크 분석: K사(社)를 중심으로)

  • Jeong, Cheon-Su;Shin, Kil-Hwan;Han, Woo-Chul
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.219-232
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    • 2011
  • The purpose of this study is to give implications for cooperative network building for general corporate IT staffs as well as operational improvement of the IT organization which is a specialized unit in general company though analysis of characteristics of communication networks of the IT organization. 39 IT employees of company "A" were surveyed and interviewed, and the data collected were analyzed in a network analysis method. The analysis shows that a variety of networks were built across employees - e.g. strong/weak ties or centralized/decentralized structure - by each communication area. IT competency network was found weak ties. Career-rela ted network showed centralized and hierarchical characteristics. At the center of each network was positioned manager of each team. To address improvement of the findings, I presented the followings: more active networking over IT competency, enhancement of work centralization and collection of research data as to communication network of IT organization.

Assessments of Creep Properties of Strip Type fiber Reinforcement (띠형 섬유보강재의 크리프 특성 평가)

  • 전한용;유중조;김홍택;김경모;김영윤
    • Journal of the Korean Geotechnical Society
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    • v.19 no.2
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    • pp.279-289
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    • 2003
  • Geosynthetic reinforced earth wall was introduced about 20 years ago and many structures have been constructed. Especially, segmental concrete panel facing and friction tie system are the most popular system in Korea, and this friction tie was composed of high tenacity PET filament and LDPE(Low Density Polyethylene) sheath. Due to the lack of direct-test results, design coefficients of friction tie (creep reduction factor) had been determined by quoting the previous and the foreign reference data. This is an unreasonable fact for the use of friction ties. In this study, the creep tests were performed to evaluate the creep behavior of friction tie, and the reduction factor of creep was calculated for the correct design of geosynthetic reinforced earth retaining walls. From the test results, finally it was found that the allowable creep strength of friction tie is 60% of Tult during service life, and creep reduction factor is 1.67 for each grade of friction ties.