• Title/Summary/Keyword: Dismantling System

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Structural Capacity Evaluation of System Scaffolding using X-Type Advanced Guardrail (교차가새형 선행 안전난간을 적용한 시스템비계의 구조 성능 평가)

  • Park, J.D.;Lee, H.S.;Shin, W.S.;Kwon, Y.J.;Park, S.E.;Yang, S.S.;Jung, K.
    • Journal of the Korean Society of Safety
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    • v.35 no.5
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    • pp.49-58
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    • 2020
  • In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

Development of a Modular Building System for the BOQ Using Six-sigma (식스-시그마를 이용한 군 독신자 숙소용 모듈러 건축 시스템 개발)

  • Cho, Bong-Ho;Lee, Jae-Sung;Cha, Hee-Sung
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.6
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    • pp.89-99
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    • 2010
  • Military Barracks and Bachelor Officer's Quarters are public buildings representing architectural characteristics with repeating the same room modules. These buildings require easy dismantling and reusing for the next generation' military re-organization. For these reasons, since 2005, the modular construction has been applied to military buildings. The most important factors required for modular military buildings are standardization, lowcost construction and reusable construction method. However, conventional modular building system have not been matched with these requirements. This study suggests a new modular system for Bachelor Officer's Quarters using Six-sigma design tool. To reflect the voices of customers, market study and surveys were carried out. Through the QFD, the voices of customers were converted into quality characteristics of building system for BOQ. The various design concepts meeting customer's requirement were derived by the QFD and Pugh matrix methodology. The proposed modular building system shows 80% increased factory production rate and 62% decreased weight of steel frame as compared with the conventional modular building system.

Spatial assessment of soil contamination by heavy metals from informal electronic waste recycling in Agbogbloshie, Ghana

  • Kyere, Vincent Nartey;Greve, Klaus;Atiemo, Sampson M.
    • Environmental Analysis Health and Toxicology
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    • v.31
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    • pp.6.1-6.10
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    • 2016
  • Objectives This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. Methods A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination ($C_{deg}$), we analyzed the individual contribution of each heavy metal contamination and the overall $C_{deg}$. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. Results Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall $C_{deg}$. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. Conclusions Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and $C_{deg}$, indicating soil contamination in AEPS with the nine heavy metals studied.

Opening and Closure Body Space Expressed in the Fashion Art

  • Huh Jung-Sun;Geum Key-Sook
    • International Journal of Costume and Fashion
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    • v.5 no.1
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    • pp.14-25
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    • 2005
  • The objective of this study is to understand bodily extension and identity in contemporary fashion art through the analysis of 'the fashion acting on the body' among the fashion theory excluding body and the conspicuous works on the opening and covering images as a fashion art as a body-space'. This study also investigated identity problems where there are poles apart in opening and closure their bodies and body-space in which its clothing types were distorted by being de-bodilization out of the traditional and ideological expression method in contemporary fashion art from a opening and closure point of view. Image of opening and closure among body-space in fashion art can be classified into opposing structure of opening and closure. Destroying the boundary between bodily opening and closure for a primary function of clothing and dismantling the role and boundary between body and clothing, opening body-space in appearance as a reemergence of body image or the border between inner and outer are being ambiguous because of transparent material. Being representative work of this study opening body-space was expressed as an opening space image using transparency. On the contrary, closure body-space was isolated from external environment and confined in the certain space, which could limit or restraint body- action. Excluding boundary of body and clothing on the whole or in part, boundary of work becomes body-space. However, these were appeared to be a work inducing unlimited curiosity and meaning from the audience. The interpretation of artistic and body-space in fashion art are indicating the role and function of the fashion art exceeding the suggestible dimensions in the every day life of fashion. The body-space of fashion art showing similar aspect of body art today could be understood that it is substituted into an metaphorical, critical space by seeing it as a symbol system connected with social space. Therefore, contemporary fashion art should be interpreted as an equivocal space looking at the body-space with open mind.

The Recycling of End-of-Life Vehicles(ELVs) in Taiwan

  • Tsai, Min-Shing;Chen, Wei-Sheng;Wu, Chung-Liu
    • Resources Recycling
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    • v.14 no.3
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    • pp.6-15
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    • 2005
  • The overall area of Taiwan is 36,006 km$^2$ and population was about 22,535,000 persons in 2003. The population density became 625persons/km$^2$. The economic of Taiwan progress since 1970. Gross national production in 2004 increased by 2.3 trillion or 493% relative to 1981. The number of automobiles in 1981 was 821,862, and increase to 6,389,186 in 2004. The number of motorcycles in 1981 were 4,591,547 and increase to 12,793,950 in 2004. The vehicle growth rate of automobile and motorcycle was 677% and 178% respectively. The recycling end-of-life vehicles(ELVs) is specified in the Waste Disposal Act. Its main content is the system of asking the vehicle manufacturer and importing agents, who are responsible for recycling of the ELVs. The recycling task on ELVs was startedinitially in 1993. It is required that the manufacturers and importing agents deposit certain ratios of Waste Vehicle Disposal Fees proportional to the number of vehicle they manufacture and import into Taiwan under sales. This report will introduce the current status of ELVs recycling in Taiwan, and the future direction, as well as measures proceeding for the EPA- Fund Management Committee(RMFC) operating in the fiture.

A Study on Fingerprinting Robustness Indicators for Immersive 360-degree Video (실감형 360도 영상 특징점 기술 강인성 지표에 관한 연구)

  • Kim, Youngmo;Park, Byeongchan;Jang, Seyoung;Yoo, Injae;Lee, Jaechung;Kim, Seok-Yoon
    • Journal of IKEEE
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    • v.24 no.3
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    • pp.743-753
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    • 2020
  • In this paper, we propose a set of robustness indicators for immersive 360-degree video. With the full-fledged service of mobile carriers' 5G networks, it is possible to use large-capacity, immersive 360-degree videos at high speed anytime, anywhere. Since it can be illegally distributed in web-hard and torrents through DRM dismantling and various video modifications, however, evaluation indicators that can objectively evaluate the filtering performance for copyright protection are required. In this paper, a robustness indicators is proposed that applies the existing 2D Video robustness indicators and considers the projection method and reproduction method, which are the characteristics of Immersive 360-degree Video. The performance evaluation experiment has been carried out for a sample filtering system and it is verified that an excellent recognition rate of 95% or more has been achieved in about 3 second execution time.

A survey of the relation between fatty lesions after slaughter inspection results and cattle carcasses quality grades in Korea (도축검사 후 지방성 병변과 축산물 품질 연관성 조사)

  • Sung, Chang-Min;Ji, Tae-Kyung;Choi, Jong-Wook;Park, Da-Hae;Park, Dae-Hee;Kim, Hyun-Joong;Kim, Yong-Hwan;Kim, Eun-Sun
    • Korean Journal of Veterinary Service
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    • v.36 no.2
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    • pp.121-125
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    • 2013
  • The survey was conducted to investigate the relation between slaughter inspection results and the quality of cattle carcasses by inquiring animal products grading service results of Korea Institute for Animal Products Quality Evaluation (KAPE) about partial-disposed cattle carcasses after dismantling inspection. Of the 13,586 slaughtered cattle, 1,343 (9.9%) cattle heads were partially disposed from January to August, 2012 at slaughterhouses in Gwangju area, Korea. Of the 1,343 partial disposed cattle, 613 (45.6%) cattle carcasses were graded into above "Grade 1". Among partially disposed 1,171 Hanwoo heads, 613 (52.3%) cattle carcasses were graded into above "Grade 1". However, none of dairy and beef cattle carcasses were graded into above "Grade 1" out of 163 and 9 partial disposals, respectively. Of the 221 partial disposals by enteric fat necrosis, 139 carcasses were graded into above "Grade 1", and the ratio; 62.9% (P=0.001), was higher than that (50.3%) of total cattle carcass grade which is above "Grade 1". From these results, it is suggested that quality of cattle carcasses which is mainly determined by marbling might be related to the fatty lesions such as fatty liver and enteric fat necrosis.

End-of-Life Vehicle Rating Classification for Remanufacturing Core Collection (재제조 코어 회수를 위한 폐자동차 등급 분류)

  • Son, Woo Hyun;Li, Wen Hao;Mok, Hak Soo
    • Resources Recycling
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    • v.27 no.2
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    • pp.11-23
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    • 2018
  • The need for remanufacturing automotive parts is required due to the depletion of resources, rising raw material prices and strengthening environmental regulations. For remanufacturing, stable supply and demand of core must be accompanied. At present, remanufacturing companies collect cores through various routes, but the recovery rate of cores from the End-of-Life Vehicles is low. If we can systematically collect cores from hundreds of thousands of ELVs that were generated each year, the recovery rate of the core for remanufacturing will be further improved. Therefore, in this paper, we tried to establish a classification system for the ELV as a method for collecting the cores from the ELV. First, we selected the elements affecting the classification and determined the scope for the evaluation. The final rating classification is established by calculating the weights among the influence elements. Finally, through the case study, the dismantling grade of the actual ELV was evaluated to derive the second grade.

Scheduling Technique for Remodeling Project of Inhabited Condition (재실 리모델링 특성을 반영한 공정계획 기법)

  • Paik, Hwa-Sook;Nam, Wook-Jin;Kim, Sung-Han;Kim, Hyung-Jin;Choi, Jong-Soo;Kim, Kyung-Hwan
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.2
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    • pp.141-149
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    • 2013
  • This paper presents a scheduling technique that reflects various constraints in remodeling project of inhabited condition. The remodeling project of inhabited condition is required more detailed planning and control due to claims by noise, vibration, dust, smells, limited lift capacity, and limited temporary stock area. Because of the constraints, complexity in scheduling is increased and earlier completion is required to reduce the possibility of safety and environment accidents. Especially, in case of inhabited condition, the scheduling should be linked day-time/night-time/weekend work. This paper proposes a structured scheduling technique to incorporate those constraints in remodeling of inhabited condition. This scheduling technique considers not only remodeling process but also dismantling, newly-construction, and residents movement. Process expression method using MS-Project also presented to keep connectivity with existing scheduling system.

An Experimental Study of Perfobond FRP-Concrete Composite Beam (퍼포본드 FRP-콘크리트 합성보의 실험적 연구)

  • Yoo, Seung-Woon;Kook, Moo-Sung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.121-127
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    • 2010
  • An experimental study of composite beam with perforated fiber reinforced polymer(FRP) plank as a permanent formwork and the tensile reinforcement was performed. A combined formwork and reinforcement system can facilitate rapid construction of concrete members since no conventional formwork is needed, which requires time consuming assembly and dismantling. In order for a smooth FRP plank to act compositely with the concrete, the surface of the FRP needs to be treated to increase its bond properties. Aggregates were bonded to the FRP plank using a commercially available epoxy and perforated web of plank. No additional flexural or shear reinforcement was provided in the beams. For comparison, two control specimens were tested. One control had no perforated hole in the web of FRP plank and the other had internal steel reinforcing bars instead of the FRP plank. The beams were loaded by central patch load to their ultimate capacity. This study demonstrates that the perforated FRP plank has the potential to serve as a permanent formwork and reinforcing for concrete beam.