Seok-Heon Yun

Unscented information filtering method for reducing multiple sensor registration error

In this paper, new filtering method for sensor registration is provided to estimate and correct error of registration parameters in multiple sensor environments. Sensor registration is based on filtering method to estimate registration parameters in multiple sensor environments. Accuracy of sensor registration can increase performance of data fusion method selected. Due to various error sources, the sensor registration has registration errors recognized as multiple objects even though multiple sensors are tracking one object. In order to estimate the error parameter, new nonlinear information filtering method is developed using minimum mean square error estimation. Instead of linearization of nonlinear function like an extended Kalman filter, information estimation through unscented prediction is used. The proposed method enables to reduce estimation error without a computation of the Jacobian matrix in case that measurement dimension is large. A computer simulation is carried out to evaluate the proposed filtering method with an extended Kalman filter.

A Case Study on Reason Analysis for Schedule Delay of Apartment House

A study was performed the analysis for the schedule delay of the public housing. To perform this study, the first study existing research literature on the cause of the schedule delay was considered. The based on existing study, this study selected the cause of schedule delay. For check of the schedule delay, this study was compared the monthly schedule and the work diary. Survey was conducted for using the selected cause of schedule delay. And the importance was calculated for using the AHP method. In a case site, the cause of the schedule delay was analyzed. The last, the delay cause was presented the map of cause of effect the based on the delay cause of a case site.

Development of a Real-time Lifting-path Tracking System of a Tower-crane for Steel Members based on an Integrated Wireless RF Modem and GPS System

Steel frame construction in high places entails many risk factors. In order to improve the safety and productivity of steel frame construction, a project to develop a robotic tower-crane has been undertaken. As the first step, a real-time lifting-path tracking system is being developed. In a previous study, a laser-based tracking system was proposed. While a laser-based tracking system requires at least three laser sensors to detect the x, y, z coordinates of a lifted steel member, a GPS-based system has an advantage over the laser-based system, in that the x, y, z coordinates of a lifted steel member can be detected by a single GPS sensor. To improve the accuracy, arelative positioning method using two GPS sensors was proposed in a previous study. This paper reports an improved GPS-based lifting-path tracking system of a tower crane based on an integrated RF modem and GPS system. The results showedthat the RF modem could successfully send the identifier information to a server a maximum distance of 1 km away from the lifted steel beam, and the lifting path information of each beam captured by the GPS-based tracking system was successfully saved together. Also, byusing an improved algorithm for the GPS relative positioning method, the deviation was reduced to 0.61 m on average.

A Study on the Improvement of Reinforcing Bar Detailing

The reinforcing steel process is composed of the development of placing drawing, cutting and bending, and the placement and fabrication of the reinforcement, and is participated in by reinforcement detailer, the fabricator and placer. Because the reinforcing steel process-from estimating and rebar detailing, to production, material tracking, billing, and general accounting-is conducted by many participant, reinforcement details based on building code and reinforcing bar detailing standards are essential. The process, however, holds some problems. Building code has been revised recently, and the utilization of placing drawings was proved to be low, and the reinforcement estimating in early stage of the process is below what is required for placement. Therefore, in this study, a survey was conducted to the reinforcement detailer, the fabricator and placer of domestic construction industry. According to the analysis of the survey, the reinforcement details on site was not standardized. The improvement in reinforcing steel detailing standards was sought by analyzing the results of the survey including reinforcement constructability.

Performance Measurement Method and Case Study for BIM based Construction Simulation System

건설공정은 현장여건의 변화와 불확실성으로 인해 예측이 어렵고 신뢰성이 결여된 계획으로 인해 불필요한 비용의 낭비와 공사기간의 증가, 프로젝트 참여주체간의 정보교류의 어려움 등이 발생한다. 따라서 시공전의 계획단계에서부터 건축시공시뮬레이션을 통해서 사전에 프로젝트의 작업들을 시뮬레이션 하여 공사이전에 문제점을 검토하고 수정하는 작업을 거쳐 보다 신뢰성 있는 계획을 세우기 위한 노력이 이루어지고 있다. 이러한 시뮬레이션 작업은 프로젝트를 수행함에 있어 계획과 진행의 관점에서 매우 중요한 역할을 하고 있고 따라서 이런 시뮬레이션 시스템의 개발과 연구 또한 활발히 진행 중이다. 그러나 현시점의 시뮬레이션 시스템은 프로젝트의 사전검토에서 주로 단순 애니메이션 용도로만 사용되고 실제 엔지니어링 업무를 지원하는 경우는 매우 드물다. 최근 들어, 다양한 엔지니어링 업무를 지원하는 시뮬레이션 시스템들이 개발되고 있으나, 이들 시스템의 적극적 활용을 위해서는 시스템의 도입효과에 대한 분석이 필수적이다. 그러나 아직까지 이러한 시뮬레이션 시스템의 도입효과를 분석하기 위한 시스템 성능 분석 방법론이 명확히 정의되어 있지 못하다. 본 연구에서는 이를 위해 건축시공시뮬레이션이 적용되는 업무 프로세스를 정의하고, 해당 업무 프로세스에서 핵심이 되는 표준 시나리오를 정의하고 이러한 시나리오를 기반으로 시뮬레이션 시스템의 성능을 분석하는 방법론을 제시하고자 한다. 그리고, 건축시공시뮬레이션 시스템을 대상으로 사례 분석을 수행하고자 한다.

Adoption of Virtual Technology to the Development of a BIM based PMIS

As construction projects become bigger, PMIS is being used as a project collaboration tool for project participants, owners, designers, inspectors and contractors. As the data type used in PMIS is usually text and most PMIS have no standard information classification system, there is a problem with data usability, such as the capacity for data search and analysis. BIM uses Objects and Properties, and this information might be used for relating with other construction information. As such, BIM technologies can be used with PMIS to enhance the data usability. The web environment is very convenient for multiple users, but the problem is that the data transfer speed is low for big files such as BIM model files. In this study, we suggested a Virtual Technology (VT) application to enhance the performance of BIM data exchange in PMIS, and tested and analyzed its efficiency when it is used to integrate BIM and PMIS in the web environment. The results of the study showed that VT can be used to enhance the efficiency of BIM data exchange in the web environment.

A Study on the Improvement through Analysis with Present Condition of Progress Management for Construction Project

As mega-sized and complex building construction projects are on the rise, the importance of project scheduling and control is being highlighted. Project scheduling and control techniques are not yet widely used in Korea, but interest in these has progressively been increasing. Until now, most research projects have mainly focused on scheduling issues, but project progress management is of equal importance. In this research, the current state of project progress management in Korea is analyzed, and ways for improvement are suggested. We begin by analyzing previous research and practical studies in this field, and then survey experts about the current state of project progress management. This study suggests the Building Information Modeling (BIM)base project progress management method for quantitative and qualitative project progress analysis. Currently, BIM is applied to design, construction and maintenance for construction projects. BIM can also contribute to improving accuracy and understanding of the current project situation.

Basic Research on BIM-Based Quantity Take-off Guidelines

Various types of building information should be linked to 3D model objects for their effective use by stakeholders. Because Building Information Modeling (BIM) based on 3D is used by different stakeholders, the created BIM need standard guidelines for each purpose, as, for example, for quantity take-off. Thus, this study was conducted to propose guidelines for BIM modeling for quantity take-off in the framework, especially, in the concrete and form. The proposed guidelines adopted each element of the BIM model based on an analysis of the problem of the general BIM model. Moreover, the usability and accuracy of the reinforced structure modeling guidelines were verified by comparing the quantity of the commercial estimation software and the modeling quantity using the proposed modeling guidelines.

Productivity Measurement and Analysis on Factors in Steel Erection

In today`s construction industry, buildings have been more complicated and higher, the demands of steel works have been increasingly concerned, which makes the schedule planning and management more significant. However, in actual construction sites, management is more based on a manager`s construction experience than productivity data accumulated in previous projects. Moreover, most of the existing studies also featured a theoretical approach rather than an analysis of data straightforwardly collected in sites. In this study, a steel-erection site was visited to collect productivity data. The study found that there were significant disparities between aboveground work productivity and underground work; one tower crane operated work and two tower crane operated; and work productivity conducted in clear weather condition, cloud and rainy. However, the productivities of `first node on ground` and `second node on ground` were estimated similar. The productivity data collected and factors affecting the productivity will help managers to plan and control their similar steel-erection works. This study will also be beneficial for those performing related studies.

Guideline of Building Information Modeling(BIM) Service Application Level using Service Level Agreement(SLA) in the Procurement Phase

Recently, BIM has been actively adopted in construction projects and industries, and also integrated with Information and Communications Technology(ICT) such as cloud computing technology, sensor technology, 3D scanning and printing technology etc. However, it is very difficult to efficiently utilize BIM services, technologies and collaborate with each other because of differences of usage and requirements of technologies. Every participant in the same construction project has their own needs, requirements and details of the model in each phase. In order to enhance utilization BIM model, BIM services and technologies required in their project have to be clearly defined in the initial stage of the project. In order to support the owner to define the BIM level, BIM service level and application technologies are identified and guidelines how to define the level and technologies for their project purpose are suggested in this study.