• Title/Summary/Keyword: web reinforcement

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Experimental Study of Reinforced High-Strength Concrete Beams without Stirrups Considering Shear Behaviour (전단보강근이 없는 고강도 콘크리트 깊은 보의 전단특성 실험연구)

  • Yang, Seong-Hwan;Lee, Dong-Jun
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.4
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    • pp.336-342
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    • 2014
  • Shear strengths of reinforced high strength concrete beams without web reinforcement are studied with experimental analysis of 10 specimen with 2.4 shear span-to-depth ratio (a/d) beams for 4 stages of concrete compressive stength over 60MPa comparing ultimate loads and shear stresses of ACI363R and KCI code equations. Expecially, concrete compressive strengths used in shear design were essentially limited to 10,000 psi (69MPa) by ACI363R and KCI Code. The modified Code equation's shear stresses of the specimen without the limit are compared with test results. The comparison between the modified exist Code equations results and test results are expected to show an available scope to apply in construction field and to give considerations of design and contraction.

Strategic Experience Design of Shortform Video-based Brand - Focused on LIZIQI's Food Videos - (숏폼(Shortform) 동영상 기반 브랜드의 전략적 경험 디자인 - 李子柒(이자칠)의 미식(美食) 동영상을 중심으로 -)

  • Cui, Ru Ru;Kim, Young Jae
    • The Journal of the Korea Contents Association
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    • v.20 no.7
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    • pp.185-194
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    • 2020
  • This study aims to figure out how the brand experience design elements works in the Shortform video-based branding through case analysis. The sense, feel, think, act, relate experience of Shortform video brand are provided through the implementation of specific experience design elements in the process of the creators expressing personality through social media channels and communicating and interacting with consumers. As a result, LIZIQI's food videos provided a brand identity as an 'Eastern gourmet' to consumers through the audiovisual stimulation of food in video, the cognitive reinforcement which is combined of identities and products, and the behavioral participation by web sites·electronic media. In addition, a strong brand relationship was established by sharing emotional ties using human factors and responsibility through co-branding. This can be extended to various Shortform video contents-based branding cases, and it will suggest a useful approach to the brand building strategy through strategic brand experience design elements.

Moment-Curvature Relationship of Structural Wells with Confined Boundary Element (단부 횡보강된 구조벽의 모멘트-곡률 관계)

  • Kang, Su-Min;Park, Hong-Gun
    • Journal of the Korea Concrete Institute
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    • v.15 no.2
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    • pp.323-334
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    • 2003
  • For performance-based design using nonlinear static analysis, it is required to predict the inelastic behavior of structural members accurately. In the present study, a nonlinear numerical analysis was peformed to develop the method describing the moment-curvature relationship of structural wall with boundary confinement. Through the numerical analysis, variations of behavioral characteristics and failure mechanism with the arrangement of vertical reinforcement and the length of boundary confinement were studied. According to the analysis, the maximum moment-carrying capacity of structural walls with adequately confined boundary elements is developed at the moment the unconfined concrete reaches the ultimate compressive strain. Walls with flexural re-bars concentrated on the boundaries fails in a brittle manner. As vortical re-bars in the web increases, the brittle failure is prevented and a ductile failure occurs. Based on the findings, moment-curvature curves for walls with a variety of re-bar arrangement were developed. According to the proposed relationships, deformability of the structural walls wth boundary confinement increases as the compressive strength of the confined concrete increases compared to the applied compressive force.

The Platform Feature Appearing in Contemporary Architectural Interior Space - Focused on the Interior Design Projects of Rem Koolhaas - (현대 실내건축공간에 나타난 플랫폼적 특성 - 렘 콜하스의 실내공간 프로젝트를 중심으로 -)

  • Kim, Suk-Young
    • Korean Institute of Interior Design Journal
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    • v.24 no.2
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    • pp.58-66
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    • 2015
  • This study was conducted to determine a 'platform' as a mean of interactions between users in contemporary spatial design and network(web) and to verify the similarity between the platform and space of Rem Koolhaas, one of the leading contemporary architects of our time. A platform, referring to tangible or intangible structures designed for common use in a variety of ways, is activated by the networking effect of participants. Aided by the recent development of the IT industry encompassing computers and smart phones, the concept of platforms is extending to all areas of modern life, in general. In this study, the similarity between architectural space and platforms after reviewing the computer-related platforms, ecological features that refer to virtuous circulation, and various cases applied with platform thinking. Through this process, the platform feature of architectural platforms is defined as the 'open spatial system combined with control and freedom that acts more than one function and facilitates direct/indirect exchanges between users regardless of its type or size'. Establishing the criteria for spatial analysis based on this definition, analysis was conducted on interior design projects that were planned and conducted by Rem Koolhaas after 2000. As a result of this analysis, it was learned that Rem Koolhaas designs space using dual space structures where the extension and mixture of the user group, mixture of various functions defined by users, loose control that induces voluntary participation, community reinforcement, and inducement of accidental events, and opening and closing coexist. In addition, this design approach was found to be a design strategy similar to the concept of platforms that began to be developed in the IT field.

Evaluation of Seismic Performances on Prestressed Composite Coupling Beams with Discontinuous Webs (불연속웨브가 도입된 프리스트레스트 합성연결보에 대한 내진성능 평가)

  • Oh, Jae Yuel;Lee, Deuck Hang;Choi, Seung Ho;Kim, Kang Su;Yi, Seong Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.1
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    • pp.133-142
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    • 2013
  • The shear wall system with coupling beams has been known as an effective means for moderate and high rise buildings up to 40 stories, because this structural system can provide the enhanced lateral stiffness compared to individual shear walls. Typical reinforced concrete coupling beams have difficulties in construction due to complicated reinforcing work on site, and steel coupling beams also have disadvantages in economical point of view because of a large number of stiffeners required for its stability under lateral loading. To overcome these disadvantages in existing coupling beam systems, this study developed the prestressed composite coupling beam with discontinuous webs, which have improved constructability, economic feasibility, and reduced sectional size. The reversed cyclic loading test on two prestressed composite coupling beams with discontinuous webs having different shear reinforcement ratios have been conducted to investigate their structural performances, and test results showed that the proposed composite coupling beams had good seismic performances.

Development of a Website-Based Nutrition Education Program for Female College Students and Young Women (여대생 및 젊은 여성층을 위한 영양교육 웹사이트 개발)

  • 김경원;강현주;김경아;김세화
    • Korean Journal of Community Nutrition
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    • v.6 no.4
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    • pp.657-667
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    • 2001
  • This study was designed to develop a website for providing nutrition information and education for college women and young women. The website focuses on two topics ; general nutrition and desirable weight control. This program is located at http : // www.ezydiet.co.kr. This program is composed of 5 major sections. The first two sections were designed to provide information ; one for general nutrition, and the other for providing information regarding weight control. The first section includes information regarding young adult women's diet, nutrition standards, such as the RDA or Korean Food Pyramid, drinking and smoking. The second section coveres information regarding desirable control, foods with high or low calories, eating disorders and popularly used dieting methods. The third section is for simple nutrition assessment, consisting of assessment of ideal body weight and obesity, energy requirements, and eating habits. The fourth section was designed to introduce and help users to apply behavioral modification techniques, such as monitoring, goal setting, stimulus control and reinforcement. The final section was designed for meal planning, by introducing a food exchange list and menu examples for one week. The characteristics of this web-based program are as follows ; 1) provide nutrition information systematically, 2) involve sections for the participation of the user, 3) include food pictures to help understanding of nutrition information, 4) include management modules for some sections to revise or update the information. One-hundred and ten female university students participated in the evaluation of this website. The evaluation results were favorable. About 90% of subjects rated that this program covers major topics 'well ' or 'very well', and that it was 'easy'to 'very easy'to understand the contents on website. Two-thirds of subjects rated quite positively on questions regarding attractiveness, overall quality and technical quality of website. In addition, about three-fourths of subjects answered that this website was helpful in increasing nutrition knowledge and in applying nutrition information into daily life. These results suggested the possibility of using a website as a means of providing nutrition information and education for young adult women.

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An Experimental Study of Cyclic Seismic Behavior of Steel Moment Connections Reinforced with Ribs (리브로 보강된 철골 모멘트 접합부의 내진거동에 관한 실험적 연구)

  • Lee, Cheol Ho;Lee, Jae Kwang;Jung, Jong Hyun;Oh, Myeong Ho;Koo, Eun Sook
    • Journal of Korean Society of Steel Construction
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    • v.14 no.4
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    • pp.499-508
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    • 2002
  • A simple design method for rib-reinforced seismic steel moment connections has been recently proposed based on the equivalent strut model. An experimental program was implemented to verify the proposed design method, as well as develop the schemes that will prevent cracking at the rib tip where stress concentration was evident. All specimens designed using the proposed method were able to develop a satisfactory connection plastic rotation of 0.04 radian. In addition to rib reinforcement, slight beam flange trimming pushed the plastic hinging and local buckling of the beam away from the rip tip and effectively reduced cracking potential at the rib tip. Using strain gage readings, the strut action of the rib and resulting reverse shear in the beam web were also experimentally identified.

Analysis of Shear Behavior of Reinforced ALWAC Beam Using Interface Elements (계면요소를 이용한 경량철근콘크리트 보의 전단거동해석)

  • Rhee, Inkyu;Kim, Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.107-115
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    • 2006
  • A challenging topic was and still is the failure behavior of concrete beams without shear reinforcement. In spite of substantial experimental and theoretical efforts in the past, the mechanism of shear failure is not entirely understood. ALWAC is of importance to the current construction industry. Most of present concrete research focuses on high performance concrete, by which in meant a cost effective material that satisfies demanding performance requirements, including durability. The advantages of ALWAC are its reduced mass and improved thermal and acoustic insulation properties, while maintaining adequate strength. In spite of these advantages, its ultimate failure behavior has not been well defined for adequate design process. This paper will investigate mainly the shear behavior of reinforced ALWAC beam without web reinforcements numerically with experimental evidences.

A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

A Study on the Cause and Improvement of Crack in the Installing Structure of the Bulkhead of Aircraft (항공기 Bulkhead 체결구조의 균열 원인 및 개선에 관한 연구)

  • Choi, Hyoung Jun;Park, Sung Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.448-454
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    • 2020
  • This study aims to determine the cause of structural defects occurring during aircraft operations and to verify the structural integrity of the improved features. The fracture plane was analyzed to verify the characteristics of the cracks and the fatigue failure leading to the final fracture was determined by the progress of the cracks by the repeated load. During aircraft operations, the comparative analysis of the load measurement data at the cracks with the aircraft design load determined that the measured load was not at the level of 30% of the design to be capable of being damaged. A gap analysis resulted in a significant stress of approximately 32 ksi at the crack site. Pre-Load testing also confirmed that the M.S. was reduced by more than 50% from +0.71 to +0.43, resulting in a sharp increase in aircraft load and the possibility of cracking when combined. Thus, structural reinforcement and the removal of the gap for aircraft cracking sites improved the defect. Based on the structural strength analysis of the improvement features, the bulkhead has a margin of about +0.88 and the fitting feature is about +0.48 versus allowable stress. In addition, the life analysis results revealed an improvement of approximately 84000 hours.