• Title/Summary/Keyword: Passive design method

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The relationship between time-varying eccentricity of load with the corner lateral displacement response of steel structure during an earthquake

  • Takin, Kambiz;Hashemi, Behrokh H.;Nekooei, Masoud
    • Steel and Composite Structures
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    • v.20 no.4
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    • pp.801-812
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    • 2016
  • In an actual design, none of the structures with shear behaviors will be designed for torsional moments. Any failure or damages to roofs, infills, shear walls, and braces caused by an earthquake, will inevitably result in relocation of center of mass and rigidity of the structure. With these changes, the dynamic characteristics of structure could be changed during an earthquake at any moment. The main objective of this paper is to obtain the relationship between time-varying eccentricity of load and corner lateral displacement. In this study, various methods have been used to determine the structural response for time-varying lateral corner displacement. As will be seen below, some of the structural calculation methods result in a significant deviation from the actual results, although these methods include the interaction effects of modes. Controlling the lateral displacement of structure can be performed in different ways such as, passive dampers, friction dampers, semi-active systems including the MR damper and active Systems. Selecting and locating these control systems is very important to bring the maximum safety with minimum cost into the structure. According to this study will be show the relation between the corner lateral displacements of structure and time-varying eccentricity by different kind of methods during an earthquake. This study will show that the response of the structure at the corners due to an earthquake can be very destructive and because of changing the eccentricity of load, calculating the maximum possible response of system can be carried out by this method. Finally, some kind of systems must be used for controlling these displacements. The results shows that, the CQC, DSC and exact methods is comply each other but the results of Vanmark method is not comfortable for these kind of buildings.

A Study on the Behavior of Diaphragm Walls by Numerieal Method (수치해석(數値解析)에 의한 지중연속벽(地中連續壁)의 거동(擧動)에 관한 연구(硏究))

  • Lee, Hyung Soo;Chung, Hyung Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.10 no.4
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    • pp.123-132
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    • 1990
  • This paper deals with the influences on the wall movements and earth pressure distribution for strutted diaphragm wall of various design depth ration and pre-displacement at strutted point. The numerical method is adopted for the study. The conclusions derived from the study were summarized as followes: 1. The elasto-plastic depth ratio in the passive region is found to decrease as such parameters as wall stiffness, soil density and penetration depth ratio decrease. 2. Values of maxium bending moments of the walls decrease with the increase of soil density, and the influence to the wall stiffness increases in proportion to the penetration depth. 3. Maximum strut reaction is found to be inversely proportional to the soil density. 4. Pre-displacement at the point of strut installation must be brougt into consideration on account of its active influence to the deflection of wall bodies.

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The Feed-forward Controller and Notch Filter Design of Single-Phase Photovoltaic Power Conditioning System for Current Ripple Mitigation (단상 PVPCS 출력 전류의 리플 개선을 위한 노치 필터 및 피드 포워드 제어기 설계)

  • Kim, Seung-Min;Yang, Seung-Dae;Choi, Ju-Yeop;Choy, Ick;Lee, Young-Gwon
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.325-330
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    • 2012
  • A single-phase PVPCS(photovoltaic power conditioning system) that contains a single phase dc-ac inverter tends to draw an ac ripple current at twice the out frequency. Such a ripple current may shorten passive elements life span and worsen output current THD. As a result, it may reduce the efficiency of the whole PVPCS system. In this paper, the ripple current propagation is analyzed, and two methods to reduce the ripple current are proposed. Firslyt, this paper presents notch filter with IP voltage controller to reject specific current ripple in single-phase PVPCS. The notch filter can be designed that suppress just only specific frequency component and no phase delay. The proposed notch filter can suppress output command signal in the ripple bandwidth for reducing output current THD. Secondly, for reducing specific current ripple, the other method is feed-forward compensation to incorporate a current control loop in the dc-dc converter. The proposed notch filter and feed-forward compensation method have been verified with computer simulation and simulation results obtained demonstrate the validity of the proposed control scheme.

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Study on Obstacle Deflector of a Railway Vehicle Using Tension-type Energy Absorbers (인장형 에너지흡수부재를 이용한 철도차량용 장애물제거기 연구)

  • Kim, Hongeik;Kim, Jinsung;Kwon, Taesoo;Jung, Hyunseung
    • Journal of the Korean Society for Railway
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    • v.20 no.2
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    • pp.173-181
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    • 2017
  • The obstacle deflector sweeps obstacles off the track or absorbs crash energy with an energy absorber to prevent derailment of a train and to minimize damage and casualties after an accident. In this study, an obstacle deflector and its operational mechanism were designed with a tension-type energy absorber and a 4-bar linkage system. Also, a test method was suggested and verified with FEA (Finite Element Analysis) and UTM (Universal Test Machine) for testing of the static load and energy absorbing ability according to EN 15227 regulations. Through this study, an obstacle deflector that meets the EN 15227 standard was designed and a test method was suggested to adjust the collapse load easily and to verify it experimentally according to the design and verification procedure of the obstacle deflector.

Fandom-Persona Design based on Social Network Analysis (소셜 네트워크 분석을 이용한 팬덤 페르소나 디자인)

  • Sul, Sanghun;Seong, Kihun
    • Journal of Internet Computing and Services
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    • v.20 no.5
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    • pp.87-94
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    • 2019
  • In this paper, the method of analyzing the unformatted data of consumers accumulated on social networks in the era of the Fourth Industrial Revolution by utilizing data from the service design and social psychology aspects was proposed. First, the fandom phenomenon, which shows subjective and collective behavior in a space on a social network rather than physical space, was defined from a data service perspective. The fandom model has been transformed into a collective level of customer Persona that has been analyzed at a personal level in traditional service design, and social network analysis that analyzes consumers' big data has been presented as an efficient way to pattern and visually analyze it. Consumer data collected through social leasing were pre-processed by column based on correlation, stability, missing, and ID-ness. Based on the above data, the company's brand strategy was divided into active and passive interventions and the effect of this strategic attitude on the growth direction of the consumer's fandom community was analyzed. To this end, the fandom model of consumers was proposed by dividing it into four strategies that the brand strategy had: stand-alone, decentralized, integrated and centralized, and the fandom shape of consumers was proposed as a growth model analysis technique that analyzes changes over time.

The Instructional Design Using Storytelling in Home Economics Education (가정교과에서의 스토리텔링(storytelling)을 활용한 수업 설계 방안)

  • Kim, Eun-Jeung
    • Journal of Korean Home Economics Education Association
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    • v.23 no.1
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    • pp.143-157
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    • 2011
  • It is a story through which people share their ideas and express their thoughts. Storytelling is temporally and spatially interconnected narration that consists of characters, background, its beginning and its conclusion. Furthermore, the story in storytelling is a means of delivering culture and history; thanks to the development of various media, delivering and exchanging the story are conducted in a variety of forms. Due to the technological advancement, the way storytelling is done has changed, which was a method called digital storytelling. This storytelling has been frequently used in education; that is, teachers utilize stories to communicate their thoughts. As receivers, students understand a shade of meaning and the role of language, thus reorganizing the important factors in the context of meaningful events. However, in practice the classes are so teacher-centered that the role of students are relegated to that of passive learners, thus debilitating the interaction between participants; as a result, this situation shows serious limitations in that it does not improve students' practical skills. Despite this situation, home economics has attempted to broaden students' practical knowledge and has enabled them to acquire procedural knowledge as its main objectives in the context of the entire life. To overcome this problem, this study attempts to demonstrate the lesson model utilizing the storytelling where the lively participation in the process and results of learning can increase learners' self-confidence and responsibility. This lesson model is believed to facilitate the communication among participants including teachers and students. Through this alternative teaching method, learners can participate in the process of learning so that they can acquire practical knowledge: this method can be a step-stone for further development. In conclusion, the development of curriculum and lesson plans should be encouraged.

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Feasibility study of a dedicated nuclear desalination system: Low-pressure Inherent heat sink Nuclear Desalination plant (LIND)

  • Kim, Ho Sik;NO, Hee Cheon;Jo, YuGwon;Wibisono, Andhika Feri;Park, Byung Ha;Choi, Jinyoung;Lee, Jeong Ik;Jeong, Yong Hoon;Cho, Nam Zin
    • Nuclear Engineering and Technology
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    • v.47 no.3
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    • pp.293-305
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    • 2015
  • In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 $MW_{th}$ and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

The Present Status Analysis of Interior Planning in a Fitness Center Inside an Apartment Complex (공동주택단지 내 휘트니스 센터 시설현황 분석에 관한 연구)

  • Cho Young-Youn
    • Korean Institute of Interior Design Journal
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    • v.14 no.4 s.51
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    • pp.87-94
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    • 2005
  • Lately due to the sudden growth of the construction of an apartment complex in domestic market, many construction companies are eager to provide various public facilities to increase the apartment distribution rate. An introduction of a fitness center is popularized as a part of such development. There has been a continuing development in a private fitness based on analyzing the user's data. However a public fitness is quite different from the private in terms of a user's classification, preference rate, the pattern of use, and location which requires a different facility plan. Nevertheless, all these days a public fitness in an apartment house has been developed without a specific facility plan based on relevant materials. It is worried that such development would cause the facilities not to function as appropriate resident facilities and sink to idle ones. Therefore the purpose of this paper is to make the standard considered in facility planning in future and the base to guide an applying method. In the paper the present condition of fitness centers inside apartment houses has been compared to analyze the progress of the existing facilities and the appropriateness of the organization and the structure division. The result of the research shows that public resident facilities is not the place to perform passive role for fixed activities but one to form a community through the human relationship based on the facility. Therefore a fitness center inside the apartment complex have to be designed to provide service and leisure space as one of main community facilities for residents. To obtain this purpose, when choosing facilities of an apartment complex, first of all the residents' standard of living, apartment size, residents' distinction rate of age and sex, the needs of the times should be fully considered Secondly, the size of each facility space have to be decided based on the practical data analysis in facility use such as space preference, average staying time. Also, future living culture requires the change of the function and space according to the change of social values, so continuing research and data analysis are required to related to fitness center inside an apartment complex in order to present systematic approaching method and the paper will be expected to be a little step toward it.

The Moderating Effect of Internet lifestyle among Relational Benefits, Customer Satisfaction and Customer Loyalty on the Internet Shopping Mall (Part II) (인터넷 쇼핑몰에서의 관계혜택이 고객만족도와 고객충성도에 미치는 효과에 대한 인터넷 라이프스타일의 조절효과 (제2보))

  • Go, Eun-Ju;Yi, Soo-Kyung;Kim, Seon-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.4
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    • pp.586-597
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    • 2009
  • The purpose of this study is to identify the moderating effect of Internet lifestyle among relational benefits effect, customer satisfaction and customer loyalty on the Internet shopping mall. For the study, utilizing the convenient sampling method, the sample of study was composed of female and male adults aged between 20 and 30 living in Seoul metropolitan area who had experienced purchase of fashion products on the web. Of 350 distributed, 311 useful questionnaires were returned. The survey research design was employed with structured questionnaire. For data analysis, descriptive statistics, factor analysis, reliability analysis, cluster analysis and multiple-regression analysis were used. The results of this study are as follows: The results of Internet lifestyle were regarding 4 cluster of Internet lifestyle. 1) information seeking type, 2) shopping maniac type, 3) social gathering type and 4) passive follower type were obtained. The interaction of psychological benefits and the type of Internet lifestyle affected customer satisfaction positively. The interaction of customer satisfaction and Internet lifestyle reinforced customer loyalty. Especially interaction of shopping maniac type among Internet lifestyle types and customer satisfaction affected customer loyalty strongly.

Design and Implementation of DB Protection System through Critical Query Signature (핵심 쿼리 결제를 통한 DB 보호 시스템 설계 및 구현)

  • Kim, Yang-Hoon;Kwon, Hyuk-Jun;Lee, Jae-Pil;Park, Chun-Oh;Kim, Jun-Woo;Chang, Hang-Bae
    • Journal of Korea Multimedia Society
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    • v.14 no.2
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    • pp.228-237
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    • 2011
  • The risk of leakage or theft of critical data which is stored in database is increasing in accordance with evolution of information security paradigm. At the same time, needs for database security have been on the rapid increase due to endless leakage of massive personal information. The existing technology for prevention of internal information leakage possesses the technical limitation to achieve security goal completely, because the passive control method including a certain security policy, which allows the only authorized person to access to DBMS, may have a limitation. Hence in this study, we propose Query Signature System which signatures the queries accessing to the critical information by interrupting and passing them. Furthermore this system can apply a constant security policy to organization and protect database system aggressively by restricting critical query of database.