• 한국주거학회논문집
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• 제9권2호
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• pp.33-41
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• 1998

To accomodate increasing housing shortage in many cities, Korean Government has implemented various residental land development projects to provide more land for new housing construction. Most of the residential areas developed by these projects were used for multi-family housing units. Under this process, the size and location of the neighborhood service facilities in the development area were regulated by uniform standards. For this reason, the neighborhood service facilities were not able to be provided according to the household density but provided in minimum status required by these standards. Based on these considerations, this study aimed to evaluated residential land development project conducted by pubilc authority, one of the residential land development projects in Korea. Results of the case studies confirmed findings from literature review and proposed that existing regulations applied to these projects need to be amended not only to accomodata unique situation of each development area but also to enhance level of the dwelling environment. As ways to resolve these problems, this study suggests followings: (1) more flexible operation of the regulations, (2) inclusion of the socio-economic characteristics of the perspective resident in planning process, and (3) introduction of design techniques in the project. Finally, this study proposed future study directions in relation to this issue.

• 국제초고층학회논문집
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• 제11권2호
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• pp.103-114
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• 2022

Tower crane is of great importance in the construction of high rise buildings. A self-lifting & slewing multi-cranes platform (referred to as crane slewing platform) was developed to optimize the configuration of tower cranes, as well as solve the problems of cooperative operation conflict between multiple cranes and other construction equipment and their respective climbing and occupying of construction period. The design and test of the slewing platform was introduced. By applying the slewing platform in the construction of Chengdu Greenland Center super high rise building project, some key technologies such as the configuration of cranes, the installation, construction and lifting of the slewing platform are implemented and validated. Up to now, the slewing platform has been safely lifted up 98 times in Chengdu Greenland Center project construction, and achieved good social and economic benefits.

• 한국정보통신학회논문지
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• 제6권2호
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• pp.221-227
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• 2002

본 논문에서는 3GPP(3rd Generation Partnership Project) 비동기(asynchronous) WCDMA(Wide-band CDMA) 시스템에 HIC(Hybrid Interference Cancellation) 기법의 MUD (Multi-User Detector)를 적용하여 Rayleigh 페이딩 채널에서 BER (Bit Error Rate) 성능을 컴퓨터 시뮬레이션을 통해 구하였다. 이 결과를 감산형 간섭제거기법의 대표적인 방식인 SIC(Successive Interference Cancellation) 기법, PIC(Parallel Interference Cancellation) 기법의 BER(Bit Error Rate) 성능과 비교 분석하였다. 분석한 결과, 전송률이 높은 사용자들은 PIC 기법이나 HIC 기법을 사용하여 간섭을 제거하는 것이 효과적이고, 전송률 이 낮은 사용자들은 SIC 기법이나 HIC 기법을 사용하는 게 효과적이라는 것을 알 수 있었다. 또한, 전송률에 의존하지 않고 모든 사용자의 성능을 고루 만족시키기 위해서는 HIC 구조를 사용하는 것이 효과적이었다. 그 이유로서는 페이딩 채널상의 이유에서 또는 원하는 서비스를 만족시키기 위해서 사용자가 전력을 높일지라도 HIC 기법에서는 전단에 사용하는 SIC에 의해 전력이 낮은 사용자들의 성능을 보장해주고 후단에 사용하는 PIC에 의해 SIC 과정에서 전력이 센 사용자가 받는, 전력이 약한 사용자로부터의 간섭이 효과적으로 제거되기 때문이다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.349-352
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• 2004

4D-CAD 시스템에 대한 공사관리 도구로서의 활용가능성이 제기되기 시작한 것은 1990년대 후반이후의 일이다. 현재까지 몇몇 4D 시스템틀이 개발 $\cdot$ 적용되고는 있으나, 상용화 및 보편화를 위한 해결되어야 할 다수의 문제점들을 가지고 있다. 특히 자연지형과 계획시설물의 형상을 함께 표현하여야 하는 토목시설물에 대한 4D 시스템 구현에 있어서는 더 많은 해결되어야할 과제들이 존재하고 있다. 토목시설물에 대한 4D 시스템 구현에 있어서의 주요문제점 중 하나는 계획 시설물의 3차원 형상을 그와 접하고 있는 자연지형과 함께 표현할 수 있는 3D 모델을 생성하는 작업량의 방대성이다. 현재까지 이러한 작업은 대부분 수작업으로 진행되어 왔으나, 본 연구에서는 수치지도로부터 얻어지는 지형 삼각망과 계획단면으로부터 생성될 수 있는 계획삼각망을 자동으로 합성할 수 있는 방법론을 제안하며, 더 나아가 양삼각망 간의 합성과정을 생략하고 4D 모델을 구현학 수 있는 방안으로서 VRML의 멀티텍스처링 (multi-texturing) 기법을 적용하는 방법론을 각각 제안하고, 실제 4D 시스템의 구성기능으로서 적용하였다. 이러한 3D 모델 생성의 간편화 기법은 토목시설물에 대한 4D 시스템의 대중화 및 보편화를 위한 핵심기술로서 활용될 수 있을 것으로 판단된다.

• Architectural research
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• 제12권2호
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• pp.85-92
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• 2010

In recent years, construction projects have been forced to cope with lack of skilled labor and increasing hazard circumstance of human operations. A construction robotic system has been frequently accomplished as one alterative for overcoming these difficulties in increasing construction quality, enhancing productivity, and improving safety. However, while the complexity of such a system increases, there are few ways to carry out an assessment of the system. This paper introduces a knowledge-based multi-criteria decision-making process to assist decision makers in systematically evaluating an automated system for a given project and quantifying its system performance index. The model employs linguistic terms and fuzzy numbers in attempts to deal with the vagueness inherent in experts' or decision makers' subjective opinions, considering the contribution resulted from their knowledge on a decision problem. As an illustrative case, the system, called Robotic-based Construction Automation, for constructing steel erection of high-rise buildings was applied into this model. The results show the model's capacities and imply the application to other extended types of construction robotic systems.

• 한국BIM학회 논문집
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• 제7권3호
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• pp.40-48
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• 2017

It only takes one failed project to wipe out an entire year's profit, when the projects are not managed efficiently. Additionally, escalating costs of materials and a competitive local construction market make subcontractors a challenge. Subcontractors have finite resources that should be allocated simultaneously across many projects in a dynamic manner. Significant scheduling problems are posed by concurrent multi-projects with limited resources. The objective of this thesis is to identify the effect of productivity changes on the total cost resulting from shifting crews across projects using a descriptive model. To effectively achieve the objective, this study has developed a descriptive cost model for a subcontractor with multi-resources and multi-projects. The model was designed for a subcontractor to use as a decision-making tool for resources allocation and scheduling. The model identified several factors affecting productivity. Moreover, when the model was tested using hypothetical data, it produced some effective combinations of resource allocation with associated total costs. Furthermore, a subcontractor minimizes total costs by balancing overtime costs, tardiness penalties, and incentive bonus, while satisfying available processing time constraints.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.314-317
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• 2004

On 9/5/2003, the planet probe “HAYABUSA” as MUSES-C project was launched by The Institute of Space and Astronautical Science. “HAYABUSA” has microwave discharge ion engines and these engines are characterized by their high efficiency and specific impulse in comparison with chemical engine. A large ion engine can be used as a planet explorer, while a small ion engine can be used as attitude control of small satellite. We have been developing a high thrust density microwave discharge ion engine using “Multi-Monopole Antenna”. The performance of this engine are: ion cost of 344W/A, propellant utilization efficiency of 52% and thrust density of 0.055mN/$\textrm{cm}^2$ for Kr gas flow rate of 2.5sccm, microwave(2.45㎓) power of 32W and acceleration voltage of l.4㎸.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1359-1363
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• 2009

The object of this research is to develop a simulation system for earthmoving operations in consideration of the impact of congestion in-between equipment and existing traffic flow around the site. The congestion in-between equipment and traffic flow affect work productivity. The conventional discrete event simulation, however, has limitations in simulating the flow of construction equipment. To consider the impact of congestion in-between equipment and existing traffic flow, in this paper, a multi-agent based simulation model that can realize characteristics of truck behavior more accurately to consider the impact of congestion was proposed. In this simulation model, multiple agents can identify environmental changes and adapt themselves to the new environment. This modeling approach is a better choice for this problem since it describes behavioral characteristics of each agent by sensing changes in dynamic surroundings. This study suggests a detailed system design of the multi-agent based simulation system.

• 국제초고층학회논문집
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• 제11권2호
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• pp.137-144
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• 2022

As one of the most important vertical transportation equipment in super high-rise buildings, the construction elevator directly affects the project period, cost, and effectiveness. The paper proposes a new construction elevator with single-guide rail and multi-cages. It can solve the problems of single construction elevator capacity shortage and efficacy decrease with height reduction, the occupancy of plan and elevation position of multiple construction elevators, and extension of total construction period by cycling operation of multi-cages on a single-guide rail. The paper focuses on the design and research of the main components of the equipment, such as the rotating guide rail mechanism, vertical bearing mast tie system, segmented electrical power supply system, group control scheduling system, and safety anti-collision system.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.689-690
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• 2015

The remodeling of multi-family houses (MFH) has emerged as a significant issue in the construction industry. Many decision makers struggle with the decision to remodel because of insufficient information including standards or methods for projecting the price of their structure after remodeling. In this context, this research analyzed the change in price of MFHs after remodeling. To achieve this research goal, (i) the price data from 14 groups (i.e., MFH renovation cases and equivalent MFH cases without remodeling) were collected, and (ii) the trend of price variation among each group was analyzed. Finally, this research suggests price variations of each group in terms of three different time points (i.e., before remodeling, after remodeling, and the present), which shows the effects of remodeling on the price of MFHs. This research offers a framework for the development of a model that will predict the price of an MFH after remodeling.