• Title/Summary/Keyword: Early Takeoff

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Influence of Innovator or Hub in Relational Network to Early Takeoff and Diffusion Size at Takeoff (관계네트워크의 정보 확산에서 혁신자와 허브가 Early Takeoff와 확산크기에 미치는 영향 연구)

  • Ohk, Kyung-Young
    • The Journal of the Korea Contents Association
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    • v.12 no.9
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    • pp.348-356
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    • 2012
  • This study is identifying early takeoff phenomenon in relational network like SNS and investigates influence of innovator or hub at early takeoff and diffusion size at takeoff point. The major finding of this study are as follows. First, multinominal-logit analysis conducted to explore the impact of innovator and hub at early stage of information diffusion and early takeoff. Hub in early stage of information diffusion impact early takeoff. Second, our study shows that innovator and hub at early stage of information diffusion impact diffusion size at takeoff point. Third, hub is more impact early takeoff and diffusion size at takeoff point then innovator. This study provides implication for professionals by confirming hub's influence in study of successful information diffusion by early takeoff. The limitation and future direction are discussed.

Improvement of BoQ Documents for the BIM based Quantity Takeoff (BIM기반 물량 및 내역정보 생성을 위한 내역서 개선방안)

  • An, Ji-Won;Yun, Seok-heon
    • Journal of KIBIM
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    • v.7 no.2
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    • pp.16-24
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    • 2017
  • It is very important to estimate accurate construction total cost needed early in the project. In the initial phase of the design, the project cost estimates are determined by total quantity from design documents and the variables that affect the calculation of the total cost of the project. In order to determine accurate total construction cost, the contractor has to produce detailed quantity information based on the drawings and specifications. The process of preparing quantification and cost estimation documents is still being worked out manually, and a lot of errors have been occurred in many cases. Recent advances in information technology have led to the BIM based quantity takeoff and cost estimation. However, there are some limits to the extent to which the current specifications for BoQ documents are computed from BIM model. This research analyze the current BoQ cases and analyze how to make quantity takeoff possible through BIM. The study defined five levels of quantity category that could be produced by BIM. Only about 40% or indirectly usable items can be used when information is extracted to BIM modelling. This is very insufficient to fill out the BoQ. The BoQ document structure quantity takeoff specifications should be simplified in order to BIM based cost estimation more efficiently.

A Study for Automated Division of Composite Walls for Quantity Take-off in Construction Document Phase (실시설계단계에서 수량산출을 위한 복합벽체 자동분할에 관한 연구)

  • Park, Seunghwa;Kim, Heungsoo;Yoon, Dooyung
    • Korean Journal of Computational Design and Engineering
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    • v.20 no.2
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    • pp.124-132
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    • 2015
  • When Building Information Modeling (BIM) was introduced at the early stage, it was only utilized as a three-dimensional visualization tool. Nowadays, however, BIM is being studied for increasing design productivity and managing enormous information on building life cycle. One of the representative research is developing 'common prototype BIM libraries'. BIM data made of common prototype libraries should be utilized in various ways, quantity takeoff, code checking, energy analysis and so on. However, common prototype BIM libraries are not enough to estimate accurate cost. For example, composite wall libraries should be divided into several single objects, wall structure and finishes, for the quantity takeoff and construction cost calculation. In this paper, we are suggesting an automated division algorithm of composite wall and developing a system prototype for it. This study is expected to reduce extra modeling work and contribute to fast and accurate cost calculation in the construction.

A Study on Vertiport Installation Standard of Drone Taxis(UAM) (드론택시(UAM)의 수직이착륙장(Vertiport) 설치기준 연구)

  • Choi, Ja-Seong;Lee, Seok-Hyun;Baek, Jeong-Seon;Hwang, Ho-Won
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.29 no.1
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    • pp.74-81
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    • 2021
  • UAM(Urban Air Mobility) systems have evolved in the form of helicopters in the 1960~1970s, tiltrotors in the 1980s, small aircraft transportation systems in the 2000s, and electric-powered Vertical Take-Off and Landing (eVTOL) in the 2010s; accordingly, the early heliport has evolved to its current form of a Vertiport. Vertical Takeoff and Landing Sites, Vertiports, are important factors for the successful introduction of UAM, along with the resolution of air traffic control (ATC), air security, and noise problems. However, there are no domestic or international installation standards and guidelines yet. Therefore, in this study, installation standards were prepared by referring to domestic and international case studies, ICAO standards, and MIT research papers. The study proposes to establish standards for Final Approach and Takeoff Area (FATO) as 1.5D, 1D for Touchdown and Lift-Off Area (TLOF), and 1.5D for Safety Area (SA). It also proposes to add "UAM Vertiport Installation Standards" to the 「Act on the Promotion and Foundation of Drone Utilization, Drone Act」.

A Trend Survey on Precision Positioning Technology for Drones (드론 정밀 측위 기술 동향)

  • J.H. Lee;J. Jeon;K. Han;Y. Cho;C.D. Lim
    • Electronics and Telecommunications Trends
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    • v.38 no.3
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    • pp.11-19
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    • 2023
  • Drones, which were early operated by remote control, have evolved to enable autonomous flight by combining various sensors and software tools. In particular, autonomous flight of drones was possible since the application of GNSS-RTK (global navigation satellite system with real-time kinematic positioning), a precision satellite navigation technology. For instance, unmanned drone delivery based on GNSS-RTK data was demonstrated for pizza delivery in Korea for the first time in 2021. However, the vulnerabilities of GNSS-RTK should be overcome for delivery drones to be commercialized. In particular, jamming in the navigation system and low positioning accuracy in urban areas should be addressed. Solving these two problems can lead to stable flight, takeoff, and landing of drones in urban areas, and the corresponding solutions are expected to establish a hybrid positioning technology. We discuss current trends in hybrid positioning technology that can either replace or complement GNSS-RTK for stable drone autonomous flight.

A Study on the Development of the BIM Process for Improvement of the BIM Application Ability of the Construction Industry (건설산업의 BIM 적용능력 제고를 위한 BIM 프로세스 개발에 관한 연구)

  • Kim, Ji-Won;Lee, Min-Cheol;Choi, Jeong-Min;Ock, Jong-Ho
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.738-743
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    • 2008
  • Recently BIM is utilized to improve productivity for Life Cycle Cost of construction projects. Therefore, the establishment of BIM process by each construction project is a necessary element. However, cases and the pertinent researches that BIM process by each project is established are still not enough in Korea. The study proposed construction of BIM process through how to set up BIM application, how to organize a BIM team, how to set up a family and modeling method in the early stage. To achieve the purpose, the study examined application ability of BIM process by carrying out basic setting and modeling work through pilot study model, examination of the amount of materials and information interchange with IFC. The study attempted making a foundation of domestic BIM guideline construction through the above examination.

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Development of an Algorithm for Automatic Quantity Take-off of Slab Rebar (슬래브 철근 물량 산출 자동화 알고리즘 개발)

  • Kim, Suhwan;Kim, Sunkuk;Suh, Sangwook;Kim, Sangchul
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.5
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    • pp.52-62
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    • 2023
  • The objective of this study is to propose an automated algorithm for precise cutting length of slab rebar complying with regulations such as anchorage length, standard hooks, and lapping length. This algorithm aims to improve the traditional manual quantity take-off process typically outsourced by external contractors. By providing accurate rebar quantity data at BBS(Bar Bending Schedule) level from the bidding phase, uncertainty in quantity take-off can be eliminated and reliance on out-sourcing reduced. In addition, the algorithm allows for early determination of precise quantities, enabling construction firms to preapre competitive and optimized bids, leading to increased profit margins during contract negotiations. The proposed algorithm not only streamlines redundant tasks across various processes, including estimating, budgeting, and BBS generation but also offers flexibility in handling post-contract structural drawing changes. In particular, the proposed algorithm, when combined with BIM, can solve the technical problems of using BIM in the early phases of construction, and the algorithm's formulas and shape codes that built as REVIT-based family files, can help saving time and manpower.

A Study on the Improvement of Domestic Navigation Safety System: Focused on the Implementation of Korea Augmentation Satellite System (국내 항행안전시스템의 개선에 관한 연구: 한국형 정밀위성항법 보강시스템의 구축을 중심으로)

  • Kim, Yeong-Pil;Hwang, Kyung Tae
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.221-230
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    • 2021
  • The study attempts to suggest potential problem and solutions expected in the process of implementing KASS, which is currently under development to improve the domestic navigation safety system, and to summarize improvement effects of domestic navigation safety system anticipated by the implementation of KASS. Challenges expected in the process of implementing KASS exists in four aspects: emotional, technical, cost, safety aspects. When KASS is implemented and operates, various benefits can be realized. Benefits include cost savings by not using navigation safety systems during takeoff and landing; reduction of flight delays and cancellations by removing airway congestion; increase of aircraft accommodation capacity; reduction of carbon emissions; preparation for future aviation demands and improvement of air transportation safety; and reduction of flight accidents. In conclusion, it is expected to enter into an era of more intense competition due to increased aviation demands. In order to survive in this competitive environment, early introduction of KASS is indispensable. Analysis results of this study are expected to provide reference information for academic research in this area. A possible future research topic include a study predicting the changes in the navigation safety systems introduced by KASS and proposing practical and useful ways to respond the changes.

Indonesia, Malaysia Airline's aircraft accidents and the Indonesian, Korean, Chinese Aviation Law and the 1999 Montreal Convention

  • Kim, Doo-Hwan
    • The Korean Journal of Air & Space Law and Policy
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    • v.30 no.2
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    • pp.37-81
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    • 2015
  • AirAsia QZ8501 Jet departed from Juanda International Airport in, Surabaya, Indonesia at 05:35 on Dec. 28, 2014 and was scheduled to arrive at Changi International Airport in Singapore at 08:30 the same day. The aircraft, an Airbus A320-200 crashed into the Java Sea on Dec. 28, 2014 carrying 162 passengers and crew off the coast of Indonesia's second largest city Surabaya on its way to Singapore. Indonesia's AirAsia jet carrying 162 people lost contact with ground control on Dec. 28, 2014. The aircraft's debris was found about 66 miles from the plane's last detected position. The 155 passengers and seven crew members aboard Flight QZ 8501, which vanished from radar 42 minutes after having departed Indonesia's second largest city of Surabaya bound for Singapore early Dec. 28, 2014. AirAsia QZ8501 had on board 137 adult passengers, 17 children and one infant, along with two pilots and five crew members in the aircraft, a majority of them Indonesian nationals. On board Flight QZ8501 were 155 Indonesian, three South Koreans, and one person each from Singapore, Malaysia and the UK. The Malaysia Airlines Flight 370 departed from Kuala Lumpur International Airport on March 8, 2014 at 00:41 local time and was scheduled to land at Beijing's Capital International Airport at 06:30 local time. Malaysia Airlines also marketed as China Southern Airlines Flight 748 (CZ748) through a code-share agreement, was a scheduled international passenger flight that disappeared on 8 March 2014 en route from Kuala Lumpur International Airport to Beijing's Capital International Airport (a distance of 2,743 miles: 4,414 km). The aircraft, a Boeing 777-200ER, last made contact with air traffic control less than an hour after takeoff. Operated by Malaysia Airlines (MAS), the aircraft carried 12 crew members and 227 passengers from 15 nations. There were 227 passengers, including 153 Chinese and 38 Malaysians, according to records. Nearly two-thirds of the passengers on Flight 370 were from China. On April 5, 2014 what could be the wreckage of the ill-fated Malaysia Airlines was found. What appeared to be the remnants of flight MH370 have been spotted drifting in a remote section of the Indian Ocean. Compensation for loss of life is vastly different between US. passengers and non-U.S. passengers. "If the claim is brought in the US. court, it's of significantly more value than if it's brought into any other court." Some victims and survivors of the Indonesian and Malaysia airline's air crash case would like to sue the lawsuit to the United States court in order to receive a larger compensation package for damage caused by an accident that occurred in the sea of Java sea and the Indian ocean and rather than taking it to the Indonesian or Malaysian court. Though each victim and survivor of the Indonesian and Malaysia airline's air crash case will receive an unconditional 113,100 Unit of Account (SDR) as an amount of compensation for damage from Indonesia's AirAsia and Malaysia Airlines in accordance with Article 21, 1 (absolute, strict, no-fault liability system) of the 1999 Montreal Convention. But if Indonesia AirAsia airlines and Malaysia Airlines cannot prove as to the following two points without fault based on Article 21, 2 (presumed faulty system) of the 1999 Montreal Convention, AirAsia of Indonesiaand Malaysia Airlines will be burdened the unlimited liability to the each victim and survivor of the Indonesian and Malaysia airline's air crash case such as (1) such damage was not due to the negligence or other wrongful act or omission of the air carrier or its servants or agents, or (2) such damage was solely due to the negligence or other wrongful act or omission of a third party. In this researcher's view for the aforementioned reasons, and under the laws of China, Indonesia, Malaysia and Korea the Chinese, Indonesian, Malaysia and Korean, some victims and survivors of the crash of the two flights are entitled to receive possibly from more than 113,100 SDR to 5 million US$ from the two airlines or from the Aviation Insurance Company based on decision of the American court. It could also be argued that it is reasonable and necessary to revise the clause referring to bodily injury to a clause mentioning personal injury based on Article 17 of the 1999 Montreal Convention so as to be included the mental injury and condolence in the near future.