• Title/Summary/Keyword: structural evaluation

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A Case Study on Earthquake Resistant Reinforcement Method for the Corner of Existing Underground R.C Box Structures using Pre-flexed Member System (프리플렉스 부재를 이용한 기존 철근콘크리트 지중박스구조물 우각부에 대한 내진보강공법 사례연구)

  • Chung, Jee-Seung;Kim, Jin-Gu;Lee, Jin-Hyuk
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.68-74
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    • 2016
  • This paper presents a new strengthening method of underground box structures against seismic loads for anti-seismic capacity improvement. A threaded steel member with pressure devices(so called 'Pre-flexed member system') is used to improve seismic capacity of the RC box structure. The pre-flexed member system is fixed the corner of opening after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. Two bracing types of strengthening methods were used; conventional bracing method and I-bracing pressure system. For the performance evaluation, seismic analyses were performed on moment and shear resisting structures with and without strength member system. Numerical results confirmed that the proposed pre-flexed member system can enhance the seismic capacity of the underground RC box structures.

Forensic Engineering Study on the Evaluation of the Structural Stability of the Mobile Crane Accident (차량크레인 전도 사고의 구조 안정성 평가에 관한 법공학적 연구)

  • Kim, Jong-Hyuk;Kim, Eui-Soo
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.11-17
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    • 2013
  • Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate the mobile crane's overturn accident in terms of the forensic engineering, in this study, we identified the accident mobile crane's position and posture before accident by the analysis of the trace resulted by the contact between the outrigger and the ground, and the accident remodeling has been performed using CATIA modeling program in the basis of the accident mobile crane's position and posture information. The accident analysis has been performed by comparing this accident remodeling and the crane's specification, the table of the allowance load about the boom's length and the working radius. Through these studies, the safety accident that may occur in mobile crane can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

Outline of Uminonakamichi Seaside Park Development Project -Urban Resort Area Development by the National Government-

  • Furusawa, Tatsuya
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.1
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    • pp.223-229
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    • 2001
  • The Uminonakamichi Seaside Park is located in Fukuoka and extends over an area of 540 ha. This Park is directly developed and managed mainly by the national government for its use for recreational facilities serving a wide area. It is planned and developed as an urban resort-type park, exploiting the rich natural environment of the area, to serve urban residents in northern Kyushu. The management of the Park is jointly conducted by nine bodies, including the national government and private enterprises. The Park has several functions, ranging form an urban resort to conservation of the natural environment and education. The Park has so far been positively evaluated by its visitors. However, the social background for the Park is changing and the park is now facing changing needs for this type of park, necessitating coordination with the development around the Park and a need to respond to the recent fiscal structural reform. Further improvement of the visitor services and the reconfirmation of the government's role in the development work are essential for the maintenance and enhancement of that attractions of this Park in the coming years.

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Structural Design of Facial Contact Parts in Computerized Tongue Diagnosis System to Block Out External Light (외부광 차단을 위한 설진기 안면접촉부 설계)

  • Kim, Ji-Hye;Nam, Dong-Hyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.17 no.3
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    • pp.225-232
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    • 2013
  • Objectives The aim of this study is to design a part in contact with the face of computerized tongue diagnosis system (CTDS), so that external light is effectively shielded even if the facial appearance and degree of protrusion differ when a patient opens or closes his/her jaws. Methods Each of the 4 researchers manually produced clay models of the part in contact with the face of CTDS. Shielding and contact feeling of the clay models were evaluated by 20 assessors. Based on the evaluation, we selected the appropriate model and produced the final silicon model. Then we evaluated the performance of the shielding of the completed silicon model. We took tongue pictures of 60 participants with a CTDS applying the silicon model in condition with external light and without it. The color values in RGB color model and gray scale of the tongue pictures in condition with external light were compared with those without external light. Results There was no significant difference between the color values of the picture taken in condition with external light and those without external light. Conclusions We concluded that the produced part in contact with the face of CTDS can effectively block out the external light.

Experimental Consideration for Vibration Noise, Heat Evaluation on High Speed Mixer (고속 교반기의 진동소음, 열특성 평가를 위한 실험적 고찰)

  • Lee, Jin-Kab
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1529-1534
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    • 2008
  • Recently, mixers are being widely used in the display and semiconductor company in order to mix the chemical materials. The mixer normally consists of shaft, hub, reduction gear, and driving motor. It is one of the key design factors to evaluate the dynamic characteristics caused by the rotation. In this study, the dynamic characteristics of the high speed mixer, such as vibration, noise and thermal radiation, are verified by the experiment. Through the experiment, it is shown that the structural unbalance mass of high speed mixer is the important source of the severe vibrations and maximum temperature is mixer bowl.

A Study on the Evaluation of Corrosion Resistance of Coated Steel Using Polymer Dispersion (폴리머 디스퍼션을 이용한 강재의 내식성 평가에 관한 연구)

  • Jo, Young-Kug
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.4
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    • pp.103-109
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    • 2003
  • Reinforced concrete structures under sever conditions such as marine structures, bridges and structural constructed with aggregated(dredged front sea). can be deteriorated from corrosion of the reinforcing bars. The purpose of this study is to evaluate the corrosion reflectance of coated steel using polymer dispersion and polymer cement slurry. Polymer dispersion and polymer cement slurry with various polymer types were coated to the surface of bars and steel plate, and tested for accelerated corrosion tests. Tests include adhesion in tension, bending test, chloride ion spray, penetration of NaCl 10% solution and carbonation. From the test results, the corrosive resistance of steel is considerably improved by using polymer dispersion and polymer cement flurry at surface of steel. The difference of the corrosive resistance is hardly recognized according to types of polymer dispersion. The coated steel using polymer dispersion and polymer foment slurry will be improved to a great extent compared to those of plain steel when increasing content of chloride ion in cement concrete.

Product Recommendation Service in Online Mass Customization: Consumers' Cognitive and Affective Responses (의류상품의 온라인 대량고객화 제품추천 서비스에 대한 소비자의 감정적, 인지적 반응)

  • Moon, Heekang;Lee, Hyun-Hwa
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.11
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    • pp.1222-1236
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    • 2012
  • This study examined the effects of product recommendation services as an atmosphere for online mass customization shopping sites on consumers' cognitive and affective responses. We conducted a between-subject experimental study using a convenience sample of college students. A total of 196 participants provided usable responses for structural equation modeling analysis. The findings of the study support the S-O-R model for a product recommendation system as an element of the shopping environment with an influence on OMC product evaluations and arousal. The results showed that OMC product recommendation service positively affected cognitive and affective responses. The findings of the study suggest that OMC retailers might pay attention to the affective and cognitive responses of consumers through product recommendation services that can enhance product evaluations and OMC usage intentions.

Development of a Set of Data for Verifying Partition Recovery Tool and Evaluation of Recovery Tool (파티션 복구 도구 검증용 데이터 세트 개발 및 도구 평가)

  • Park, Songyee;Hur, Gimin;Lee, Sang-jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.6
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    • pp.1397-1404
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    • 2017
  • When a digital forensic investigation is conducted on a damaged storage medium, recovery is performed using a recovery tool. But the result of each recovery tool is different depending on the tools. Therefore, it is necessary to identify and use the performance and limitations of the tool for accurate investigation. In this paper, we propose a scenario considering the disk recognition type such as MBR, GPT and the structural characteristics of FAT32 and NTFS filesystem to verify the performance of the partition recovery tool. And then We validate the existing tools with the data set built on the scenarios.

Characteristics of tantalum nitride thin film resistors deposited on $SiO_2/Si$ substrate using D.C-magnetron sputtering

  • Cuong, Nguyen Duy;Phuong, Nguyen Mai;Kim, Dong-Jin;Kang, Byoung-Don;Kim, Chang-Soo;Yoon, Soon-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.64-65
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    • 2005
  • The structural and electrical properties of the films are investigated as a function of nitrogen/argon ratio at room temperature and at various deposition temperatures. The phase changes as $Ta_2N$ or TaN in the films were observed as nitrogen/argon ratio increases from 3% to 25%. The phase changes were associated with a change in the resistivity and TCR (temperature coefficient of resistance) of the films. TCR values of the films deposited at room temperature and different nitrogen contents were negative, and strongly decreased with the increase in nitrogen/argon ratio. The Ta2N films deposited at nitrogen/argon ratio of 3% show improved TCR values and thermal stability with increasing deposition temperature. The $Ta_2N$ films grown at nitrogen/argon ratio of 3% and the temperature of $200^{\circ}C$ showed a TCR value of -47 $ppm/^{\circ}C$, which is close to near-zero TCR in the range of deposition temperature.

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Evaluation of Allowable Bending Stress of Dimension Lumber; Confidence Levels and Size-adjustment

  • Pang, Sung-Jun;Lee, Jun-Jae;Oh, Jung-Kwon
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.5
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    • pp.432-439
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    • 2013
  • The aim of this study was to investigate the processes for evaluating the allowable bending stress. The confidence levels and the size-adjustment in standards were reviewed with experimental data. The results show that, (1) KS F 2152 was more strict than others overseas standards due to the higher confidence level. The 5% NTL of bending strengths by a method in KS F 2152 were lower than the overseas standards and more specimens were required for evaluating the structural properties according to KS F 2152. (2) Due to the absence of size-adjustment method in domestic standards, the specified size and the exponential parameters on the size-adjustment equation were reviewed by size factors. The specified size (width: 286 mm, length: 6096 mm), and the exponential parameters (w: 0.29, l: 0.14) will be suitable for developing the allowable bending stress in domestic standard. (3) The size adjusted allowable bending stresses of No. 2 grade Korean pine were lower than the allowable stresses tabulated in KBC even though less strict method (75% confidence level) to calculate 5% value was used. The allowable stresses tabulated in KBC are needed to be reviewed by continuous experimental data.