• Title/Summary/Keyword: structural evaluation

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Tensile Strength of Plate with Bolt Hole and Bearing Strength of Bolted Connection by Oxygen Torch Cut (볼트홀을 산소토치로 천공한 강재의 인장강도 및 지압이음강도)

  • Park, Yong Myung;Lee, Kun Joon;Kim, Dong Hyun;Ju, Ho Jung
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.617-626
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    • 2014
  • In this paper, experiments for the evaluation of tensile strength of steel plate with bolt hole and bearing strength of bolted connection were performed, where bolt holes were punched by drilling and oxygen torch, respectively. For the tensile tests, drilled and oxygen torch punched steel plate specimens of 10mm and 15mm thickness were made from structural angles and H-shapes, respectively. For the bearing strength evaluation, test specimens were fabricated with base plates and splice plates those were also punched by drilling and oxygen torch, respectively. The Vicker's hardness were measured around the bolt hole to investigate material property change due to heat effect by oxygen torch cut. Numerical analysis was also performed to investigate the bearing strength of bolted joints due to the increase of hardness around the bolt hole by oxygen torch cut.

A Study on the Thermal Environment Evaluation of 'Hanok' considering Solid Model of Building Elements (한옥의 건축요소 솔리드 모델링을 통한 열환경 평가에 관한 연구)

  • Park, Tong-So;Sheen, Dong-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.955-961
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    • 2013
  • This study aimed for the scientific approach of Korean traditional house, so called Hanok, by analyses of structural elements and thermal environmental performance. Hanok is a very unique vernacular architectural style of the Middle East Asia that fits with climate conditions of the Korean Peninsular, designed to withstand high temperature and humidity in summer and cold and dry in winter seasons. In order to evaluate thermal environment of Hanok, its sectional structure such as floor, wall, roof structure and Ondol which is Korean traditional floor heating system, was built in 3D, as well as heat transfer mechanism of its composing elements was analyzed through 3 dimensional steady state analysis. The results of the thermal environmental performance of Hanok will be used as a basic datum of design guidelines for accomplishing ecologic housing fitted with local climate.

The Determinant Factors of Media in Solving Performance Assessment Task of Elementary and Middle School Students (수행평가 과제 해결에 있어 초·중학생의 매체 결정 요인에 관한 연구)

  • Lee, Seung-Min;Lee, Byung-Ki
    • Journal of Korean Library and Information Science Society
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    • v.48 no.3
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    • pp.131-152
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    • 2017
  • The purpose of this study was to investigate the relationship between media richness, media usefulness, media experience and media decision in order to identify factors that determine the media of school library in solving performance evaluation tasks. For this purpose, 132 primary and middle school students were surveyed and their structural equation was set up by hypothesis setting, validity test, and causal model. As a result, it was confirmed that media experience of school library is a major factor in media decision. Also, media richness and media experience appeared to influence media decision through media usefulness. The analysis implies that school library is centered on teaching - learning process and evaluation, so information literacy education should be carried out in school curriculum and school library is required to provide students experience on media as the center of school education.

A Study on the Development of Design Indicator and User Participation Design for Green Remodeling of School Facilitiess (학교시설의 그린리모델링을 위한 디자인지표 개발 및 사용자참여설계 활용에 관한 연구)

  • Kim, Eun-Hee;Ryu, Soo-Hoon
    • Journal of the Korean Institute of Educational Facilities
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    • v.24 no.3
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    • pp.3-13
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    • 2017
  • This study has developed a design indicator required to promote green remodeling in school facilities. And, implemented the green remodeling pilot test on the school facilities that are planning actual remodeling. This pilot test suggested user participation design methodology such as verification of the developed design indicator, design goal setting, evaluation and adjustment of design proposal. The Green Remodeling Design Indicators were classified into 3 large categories of architectural performance, usability, and design through analysis of cases related to 'green buildings' and 'remodeling'. We have developed nine middle categories such as architectural and structural performance, facility performance, environmentally-friendly, circulation, space, amenity, harmony with surroundings, form and symbolization. In addition, 42 detailed indicators were developed for each category, including general, functional, and special indicators. For the verification of this study, two green remodeling design workshops were conducted for Gwangju J elementary school. The first design workshop presented the importance of the design indicator and set the goal of the design plan of green remodeling for project. And, the second Workshop presented the evaluation of the satisfaction with the design and the direction of future adjustment for project. The design indicator developed in this study can be utilized as a design indicator of design quality management and decision system for the school green remodeling in the future. In addition, by accumulating information on the Green Remodeling Project, it is necessary to spread green remodeling and construct a sustainable building environment.

Crashworthiness Evaluation of Bridge Barriers Built with Hot-dip Zinc-aluminium-magnesium Alloy-coated Steel (고내식성 용융합금도금강판 적용 교량난간의 충돌성능 평가)

  • Noh, Myung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.171-176
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    • 2016
  • This paper proposes road safety facilities applying Hot-dip zinc-aluminum-magnesium alloy-coated steel sheets and coils to reduce the loss of function caused by the corrosion of steel in the service state. Vehicle crash simulations and full-scale crash tests were carried out to provide reliable information on evaluating the crash performance with the products of road safety facilities built with hot-dip zinc-aluminum-magnesium alloy-coated steel. From the results of the simulations and full-scale crash tests, the impact behaviors evaluated by the three-dimensional crash simulations considering the strain-rate dependency in a constitutive model were similar to those obtained from the full-scale crash test results. The full-scale crash test results met the crashworthiness evaluation criteria; hence, the proposed bridge barrier in this paper is ready for field applications.

Performance Evaluation of Stator-Rotor Cascade System Considering Flow Viscosity and Aeroelastic Deformation Effects (유동점성 및 공탄성 변형효과를 고려한 스테이터-로터 케스케이드 시스템의 성능평가)

  • Kim, Dong-Hyun;Kim, Yu-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.1
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    • pp.72-78
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    • 2008
  • In this study, advanced (fluid-structure interaction (FSI)) analysis system has been developed in order to predict turbine cascade performance with blade deformation effect due to aerodynamic loads. Intereference effects due to the relative movement of the rotor cascade with respect to the stator cascade are also considered. Reynolds-averaged Navier-Stokes equations with one equation Spalart-Allmaras and two-equation k-ω SST turbulence models are solved to accurately predict fluid dynamic loads considering flow separation effects. A fully implicit time marching scheme based on the (coupled Newmark time-integration method) with high artificial damping is efficiently used to compute the complex fluid-structure interaction problem. Predicted aerodynamic performance considering structural deformation effect of the blade shows somewhat different results compared to the case of rigid blade model. Cascade performance evaluations for different elastic axis positions are importantly presented and its aeroelastic effects are investigated.

Opinions of Hospital Staffs on the Korean Hospital Standardization Program and Its Criteria for Quality Activities (병원표준화심사의 질 향상 관련 항목에 대한 평가와 개선방안)

  • Kim, Chang-Yup;Lee, Sang-Il;Lee, Kun-Sei;Shin, Young-Soo
    • Quality Improvement in Health Care
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    • v.2 no.1
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    • pp.126-135
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    • 1995
  • Background: Korean Hospital Standardization Program(KHSP), as a hospital accreditation program initiated and promoted by Korean Hospital Association since 1981, has played a key role in the hospital quality improvement in structural aspect particularly. Recently, however, KHSP has been critisized by hospitals and health personnels in that it is unpractical to be utilized as an initiative to improve hospital quality. In particular, the section of quality assurance in KHSP, strongly influenced by old version of Hospital Accreditation of Joint Commission in U.S.A., has been required to be fundamentally revised. For design of new criteria in quality assurance section, a survey for evaluation of existing program and collection of opinions for ideal one was conducted. Methods: For a month in 1994, structured questionnaires were administered by mailing to 470 hospital staffs from 200 hospitals, participated in the survey for the 1994 KHSP in each hospital. The total number of respondents was 116. Results: Less than half of the respondents(34.5%) value positively on the impact of current KHSP in general on the quality improvement of their hospitals. Moreover, most responses indicated that KHSP should be reorganized towards more practical and applicable one. Current KHSP criteria for quality activities in hospitals were regarded as a unpractical one which should be basically renewed. For new criteria and standards, most respondents emphasized the importance of applicability of those in real situations. Conclusion: For the KHSP to be effective, new evaluation criteria for quality activities should be more practical and fully accommodated to hospital situations in reality.

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Tensile strength evaluation of SFRC subjected to high temperature using double punch test (DPT 실험을 이용한 고온노출된 강섬유보강콘크리트의 인장강도 평가)

  • Moon, Do-Young;Chang, Soo-Ho;Bae, Gyu-Jin;Lee, Gyu-Pil;Kim, Hee-Sung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.1
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    • pp.1-11
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    • 2013
  • Steel fiber-reinforced concrete (SFRC) is widely used for tunnel lining structure such as shot-crete in NATM tunnel and segment in TBM tunnel. In tunnel fire accidents, structural performance of a lining is very important because the lining is the structure that directly exposed to fire. In this study, the effects of high temperatures, mix ratios and types on failure pattern, DPT tensile strength and coefficient of variation were investigated through Double Punch Tests (DPT) of SFRC subjected to high temperatures. In the results, it is confirmed that the residual DPT tensile strength increases as for SFRC and this is more in SFRC with higher mix ratio. But, the equation for evaluation of DPT tensile strength does not involve the number of failure surfaces SFRC specimens subjected to high temperatures, therefore, it is required to investigate more fracture energy in DPT tests.

Evaluation of Nondestructive Diagnosis and Material Characteristics of Stone Lantern at Damyang Gaeseonsaji Temple Site in Korea

  • Lee, Chan Hee;Araki, Naruto
    • Journal of Conservation Science
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    • v.35 no.4
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    • pp.279-293
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    • 2019
  • The stone lantern of the Damyang Gaeseonsaji temple site is a cultural heritage built during the Unified Silla period (AD 868). The reason for its value as a cultural property is due to wittern the background and the period created on inscription of the lamp stone engraved by letters. The stone lantern consists of two types of lithic tuffs for the 23 original properties, the replaced stones in 1991, and the biotite granite for its ground stones replaced in 2005. The lithic tuffs selected as the replacement parts in 1991 and 2017 have been examined and got to properties of hardly exposure moisture as well as very similar geochemical characteristics. There were various types of physical deterioration of the stone properties and structural cracks; in particular, on the northern side of the stylobates. Chemical and biological deterioration can be identified as black, white, and brown discolorations as well as by the presence of lichens, bryophytes, and herbaceous plants. In the evaluation of the physical properties of the stone lantern, the mean and maximum ultrasonic velocities were found to be similar in each direction. However, the lowest velocity on the east and south sides were found to be lower than those of other stone properties. It was found that physical damage to the stylobates resulted from water expansion in a freeze-to-thaw phenomena related to water content. Therefore, dismantling repair was carried out in the protection facility to restrict further water supply to the stone as much as possible.

Durability Evaluation of the Korean Gauge - Adjustable Wheelset System (궤간가변 윤축시스템의 내구성 평가)

  • Ahn, Seung-Ho;Chung, Kwang-Woo;Jang, Seung-Ho;Kim, Chul-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.5669-5675
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    • 2012
  • To reduce the cost and the time of transport in Eurasian railroad networks such as TKR(Trans-Korea Railway), TCR(Trans-China Railway) and TSR(Trans-Siberia Railway) owing to the problem of different track gauges (narrow/standard/broad gauge), it is important to develop the gauge-adjustable wheelset(GAW) system to adapt easily to these gauges. The Korean GAW system is developing and will be adapting to the brand new freight trains' to improve the conventional overseas GAW system. In this study, structural and durability analyses are performed from the viewpoint of the safe-life design. The core parts of the system might be safe in range of $1{\times}10^7$ cycles from the result of durability analysis. Moreover, to examine the safety of the system while running on a track, rig fatigue test was performed according to UIC code. The safety of the Korean GAW system is demonstrated through testing that all safety-relevant conditions are satisfied.