• Title/Summary/Keyword: Overrun

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An Automated Process to Produce Shop Drawings for MEP Works in BIM Environment (BIM기반 MEP공사 시공용 도면 작성 자동화 프로세스 제안)

  • Choi, Chang-Hyun;Kwon, Dae-Yong;Cho, Sang-Ho;Kim, Ju-Hyung
    • Journal of KIBIM
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    • v.10 no.4
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    • pp.22-31
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    • 2020
  • Shop drawing tasks conducted after finishing coordinated or engineering design have great influences on the quality and cost of a project. However, despite the development of commercial BIM applications, shop drawings have mainly produced manually in certain engineering fields. Incorrect shop drawings with human errors have occurred various problems such as cost overrun, time delay and reworks. An automated shop drawing publishing from BIM is expected to resolve these problems. Despite attempts for automate shop drawing production, the field of mechanical, electrical and plumbing (MEP) is yet regarded challenging due to complexity of components and connection. In this research, we develop a process for automated producing 3D MEP shop drawings in BIM environment as following steps: to analyze conventional MEP shop drawing process, to identify detailed process that can be automated, to classify existing MEP objects and assign codes usable in BIM, and to develop an application. The validation of automated process is conducted against 10 clean room projects in which MEP is more complex and its cost is higher than other projects in terms of productivity and workers' satisfaction. Results show that the number of manpower for shop drawing is reduced by 30%, and the working time is shortened by 31%. Personal opinions of involved practitioners is interpreted as positive as the average rate of agrement on practicability, easy-to-use and necessary retouch tasks is around 66%.

Competency Level Evaluation for Construction Management in Southeast Asian Countries

  • Kwon, Nahyun;Park, Moonseo;Lee, Hyun-Soo;Son, Bo-Sik;Kim, Junyoung;Kwon, Byung-Gi
    • International conference on construction engineering and project management
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    • 2017.10a
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    • pp.146-152
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    • 2017
  • Recently, countries in the South-east Asia are making efforts to enhance the construction industry system and introduce the construction management system. However, it is challenging to apply construction management in site due to lack of technology and professionals for CM. This can result in frequent safety accidents, cost overrun, schedule delay, etc. Therefore, it is necessary to carry out a clear evaluation of the overall situation regarding the level of technology and required competency. The objective of this research is to investigate on which management skills and items for CM are required to improve the construction management skills in South-east Asian construction industry. As a result of the questionnaire, most of the officials selected that the design phase and the construction phase are important works, and the engineers evaluated activities during the bidding phase, the design phase and the construction phase as important works for construction management. However, in most of the results, it was observed that the current competency of Vietnam construction is insufficient compared to the evaluated importance of the skills. This can be explained by the fact that they are not capable of managing construction projects effectively as compared to the importance. The results can help to realize the inadequate aspects of local construction industry, which will be the basis of improvements. Also, it is expected to be supportive to improve construction management in the countries and also provide indicators related to work stage or technology that should be acknowledged when establishing the advancing strategy for Southeast Asian countries in the future.

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Standardization of Factors Classification Associated with Cost and Schedule Variations in Road Construction Projects (도로건설공사 공사비·공사기간 증감요인 분류체계 표준화 연구)

  • Mun, Junbu;Lee, Juhui;Baek, Seungwon;Lee, Kangwook;Yun, Sungmin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.821-830
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    • 2023
  • Various studies has tried to unveil causes of cost overrun and schedule delay in the road construction project. However, these causes need standardization due to difference by guidelines, relevant research, and facilities. Therefore, this study identifies and elaborate standard road construction cost and schedule variation factors that can be used in the planning and execution of the project. variation factors have been derived and grouped through literature review and modified and supplemented through expert interview. In addition, the connection with the relevant guidance factors is confirmed and the usability is reviewed by applying actual road construction cases. The factors suggested in this study comprehensively include factors of related guidelines and previous research, more clearly distinguish, support decision making.

Effects of pH and Natural Polysaccharide Gums on the Foam Stability of Soy Protein Isolate (pH와 천연 다당류 고무질이 분리대두단백질의 거품안정성에 미치는 영향)

  • Yang, Seung-Taek;Kim, Mi-Sook;Park, Chun-Og
    • Korean Journal of Food Science and Technology
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    • v.24 no.5
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    • pp.482-491
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    • 1992
  • Experiments were conducted to elucidate the effects of pH change and sodium alginate, gum karaya and gum arabic on the foaming properties of soy protein isolate (SPI). The surface tensions of SPI solution (5%) adding to gums at pH 4.0 and 5.0, near the isoelectric point (pH 4.5) were higher than those at pH 7.0 and 8.0. Specific viscosity of the solutions adding to gums (0.1, 0.2 and 0.3%) at pH 7.0 and 8.0 were $3.6{\sim}51.8$ and $4.0{\sim}51.2$, respectively. In cases of addition of sodium alginates specific viscosity were predominantly increased, while those of gum arabic did not almost increase. Addition of gums reduced the overrun, but it stabilized the foams, especially those of sodium alginates (0.2%) increased the foam stability at pH 5.0, 7.0 and 8.0 by 57, 413 and 315%, respectively. Foaming ability, foam stability and heat stability of the foam were significantly (p<0.05) affected by changing pH. There was a tendency to increase the foaming ability according to the decrease of surface tension. Specific viscosity was also important in foam stability and heat stability.

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Service Factor is Effect on Revisiting for Old People : Centering around Mediator Effect for Feeding Satisfaction (서비스요인이 재이용의도에 미치는 영향 : 급식만족도의 매개효과를 중심으로)

  • Kim, Yoon Hee;Ha, Kyu Su
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.2
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    • pp.59-67
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    • 2015
  • This studying is on the degree of reuse that runs from Seoul Palace Y elderly welfare and general social demographic is to the welfare service factors of the path Restaurant (hygiene, workers, convenience, food, accessibility, environmental, and social relationships), and influence, the process of was to effect on determining on to the mediating effect on the satisfaction with the meals ages overrun 65 years using the path restaurant was applied to the final total of 310 valid samples were subjects. We take advantage of SPSS 19.0, the first study showed that rental housing other all the factors affecting the satisfaction of catering service factor analysis of the demographic characteristics. Showed Secondly, characteristics and service factors, one of the demographic characteristics education, service factors that affect all of the factors identified in the reuse of reclaimed relationship satisfaction and feed results. Third, there are the demographic characteristics and service factors and the relationship of re-verifying the mediating effect of feeding satisfaction results, effects a positive the degree of reuse factor and the employees of the catering service satisfaction. Therefore, continued and investment is outer required the efforts of local governments for quality of service and satisfaction path restaurant you will be looking improving them for ways towards attention improve the multilateral environmental Furthermore Feed.

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The Case Study on Performance Measurement Weighting for Efficient Value Engineering Study of Sewage Treatment Facliity (건설사업의 효율적인 리스크관리를 위한 RBES 분석기법과 적용에 대한 연구)

  • Park, Jaeil;Kim, Dongjin;Kim, Gyeonghyun;Lim, Jongkwon;Lee, Minjaee
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.3
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    • pp.125-133
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    • 2016
  • The Project Risk Management is intended to result in the effective management by identifying in advance and mitigating all significant risks including project risks and opportunities during the entire project life cycle - from project inception to completion of construction. It is impossible to predict an exact budget and construction duration before finishing a project. So, Washington Department of Transportation mandates that workshop-based risk management is conducted for projects over specific cost. However, the domestic construction sites have depended on numerical risk analysis without any workshop and efficient risk management have not made. Therefore, in this study, we propose the effective risk management using the RBES program which is very useful for workshop-based risk management and pre & post mitigation, by workshop-based risk management techniques. This proposed risk management approach is applied to a domestic 'A' river recovery project. It is concluded that we may expect the effect to mitigate the total cost overrun problem and the construction duration delay effect in the project by identifying significant risks and by preparing effective risk mitigation strategies.

A Suitability Study and Development of Low Strength Perlite Concrete as Aircraft Rapid Arresting System (항공기 과주방지 포장시스템에 적합한 저강도 펄라이트 콘크리트의 개발 및 적합성 연구)

  • Kim, Choon-Seon;Lee, Young-Soo;Ha, Wook-Jai;Han, Jae-Hyun
    • International Journal of Highway Engineering
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    • v.12 no.3
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    • pp.59-70
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    • 2010
  • More than 10 different cases of airline overrun accidents happened annually home and abroad in recent years. So the government put the guidelines to protect that kinds of accidents, which is named 'Runway End Safety Area'. However, the great part of airports are far from the standards, because most of the airports have been built before the guidelines. Moreover, in many cases natural obstacles, ambiance, and local area developments obstruct the extension of the runway to meet the criteria. For these reasons, the Federal Aviation Administration (FAA) recommends that the aviation fields construct 'Aircraft Rapid Arresting System(ARAS)' at the end of the runway. Many airdromes have been constructing the system and some airports have already completed the construction. In this research, our team performed a basic study about low strength perlite concrete to provide the proper material with 'ARAS'. As a result, the unit weight of the low strength perlite concrete was $4.5{\sim}6.4kN/m^3$ and uniaxial compressive strength was measured in the range of $400{\sim}1,470kN/m^2$. In addition, we tested penetration compressive strength by using CBR tester, and we observed that the strength was increased after around 60% of penetration rate. Also, 40% of penetration rate was measured through the penetration test with dump trucks.

A Study on Takeoff Decision Speed Improvement of Air Transport Airplane (운송용항공기의 이륙단념속도 개선에 관한 연구)

  • Noh, Kun-Doo;Choi, Youn-Chul;Yoo, Kwang-Eui
    • Journal of Korean Society of Transportation
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    • v.23 no.4 s.82
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    • pp.7-16
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    • 2005
  • Rejected Takeoff Accidents are not common. but if occurred, it leads to big disaster From the year of 1959, when Jet Transport service opened, to the year of 2000, Rejected Takeoff accidents/incidents occurred total of 94 cases. All cases led to overrun, and major cause is to initiate stopping maneuvers over $V_1$, takeoff decision speed, according to National Transport Safety Board of America. Similar results are represented in Aviation Safety Reporting System of National Aeronautics and Space Administration. So I believe that it is worth studying if Airplane Flight Manual, which is the reference Performance criteria, is appropriate to operations of line pilots. The definition of $V_1$ has been revised a couple of times and Rejected Takeoff Certification Standards for Transport Airplanes was changed in 1998. It shows that up to now there are some portions unreasonable. This study focused on gathering the pilot's tendency for current Rejected Takeoff Procedures of K airlines and analyze the factors they concern. I chose B777 airplane and actually measured the recognition and reaction time of the rejected takeoff transitions through Simulators. And compared the results with the data of flight test and Airplane Flight Manual.

Influence of Intracerebroventricular Isoproterenol on the Renal Function of the Rabbit (가토신장기능에 미치는 측뇌실내 Isoproterenol의 영향)

  • Kim, Haeng-Bae;Choi, Bong-Kyu;Kook, Young-Johng
    • The Korean Journal of Pharmacology
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    • v.18 no.1
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    • pp.1-10
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    • 1982
  • In an attempt to delineate the role of beta-adrenoceptors found to be existing in the brain tissue in the central regulation of renal function, isoproterenol, a ${\beta}-adrenergic$ agonist, was administered directly into a lateral ventricle of the rabbit brain and the changes of renal function were observed. Also, the effects of propranolol, a specific ${\beta}-adrenergic$ blocking agent, and its influence upon the isoproterenol action were studied. Isoproterenol, in doses ranging from 5 to $50\;{\mu}g/kg\;i.c.v.$, elicited antidiuresis which seemed to be related to the decreased renal hemodynamics brought about by the systemic hypotension. With moderate doaes of $15\;{\mu}g/kg$ the antidiuresis was less prominent and there was a tendency toward natriuresis, but with higher doses the natriuretic effect became less evident, overrun by the systemic hypotension. Propranolol, $500\;{\mu}g/kg\;i.c.v.$, produced little effect on the renal function, but it eliminated the antidiuretic action of $50\;{\mu}g/kg$ isoproterenol i.c.v. and reversed it to a diuretic and natriuretic one, along with increases in renal plasma flow and glomerular filtration rate. The systemic hypotension also was markedly attenuated by propranolol pretreatment. Thus, it was evident that the renal action of i.c.v. isoproterenol was not blocked by propranolol and became explicit only when the hypotensive action of isoproterenol which seems to he propranolol-sensitive is removed. Various possibilities to account for this disparity in sensitivity were discussed. It is suggested from these observations that the central ${\beta}-adrenoceptors$ might also be involved in the regulation of renal function along with ${\alpha}-adrenoceptors$, though less significant than the latter.

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A Study on Evaluation of Aircraft Rapid Arresting System Using the Numerical Analysis (수치해석을 이용한 항공기 과주방지 포장시스템의 평가방법에 관한 연구)

  • Lee, Young-Soo;Kim, Choon-Seon;Ha, Wook-Jai;Han, Jae-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.185-195
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    • 2011
  • Aircraft-related accidents cause mass casualties and major material damages. At present, runway-related accidents in our country account for 28% of all air accidents. Furthermore, internationally 33% of all air accidents is connected with runway. To prevent these accidents, FAA mandates the installation of aircraft rapid arresting system(ARAS) at the runway end safety areas which do not meet the FAA requirements. Even if the areas satisfy the conditions, FAA recommends the installation of ARAS to ensure the safety. In accordance of the international affairs, the domestic studies for ARAS are in progress and the legal formalities for domestic adoption of ARAS is under way. In this study, we analyzed the stopping distance, drag force, vertical force and tire penetration of runway overrun to assess the performance of ARAS reasonably by using two different kinds of analysis programs. The first is ARRESTOR program adopted by FAA, and the second is LS-DYNA which is available for 3-dimensional nonlineal dynamic analysis. As a result, analytically the stopping distances between two programs are similar. The drag force is rather different, but the tendencies are similar. Later on, the 3-dimensional simulation analysis considering various air-craft condition and properties of packaging materials is necessary. In addition, ongoing development of simulation analysis program is required for more accurate analistic results.