• ETRI Journal
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• 제40권5호
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• pp.664-676
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• 2018

Given the rapidly increasing market penetration of photovoltaic (PV) systems in many fields, including construction and housing, the effective maintenance of PV systems through remote monitoring at the panel level has attracted attention to quickly detect faults that cause reductions in yearly PV energy production, and which can reduce the whole-life cost. A key point of PV monitoring at the panel level is cost-effectiveness, as the installation of the massive PV panels that comprise PV systems is showing rapid growth in the market. This paper proposes an implementation method that involves the use of a panel-level wireless PV monitoring module (WPMM), and which assesses the cost-effectiveness of this approach. To maximize the cost-effectiveness, the designed WPMM uses a voltage-divider scheme for voltage metering and a shunt-resistor scheme for current metering. In addition, the proposed method offsets the effect of element errors by extracting calibration parameters. Furthermore, a design method is presented for portable and user-friendly PV monitoring, and demonstration results using a commercial 30-kW PV system are described.

• 한국재난정보학회 논문집
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• 제16권2호
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• pp.331-342
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• 2020

연구목적: 본 연구는 건설업에서의 사고·장애 예방을 위해 시행되고 있는 안전관리비 제도의 문제점과 개선방안 도출을 목적으로 한다. 연구방법: 연구를 위하여 건설안전관리자 20명을 대상으로 세부 설문지를 개발하여 전문가집단인터뷰(FGI) 분석기법을 시행하고 분석하였다. 연구결과: 분석결과 '안전관리비 제도의 이해'를 위해 기준 매뉴얼 작성, 정기 현장교육 시행, 안전관리비 모니터링 시스템 구축 등의 대안이 도출되었고, '안전관리비 제도의 효율성과 필요성'을 개선하기 위해 이례상황 시 즉시 투입할 수 있도록 유연한 비용 집행의 자율성을 보장할 필요성이 있으며, 과도한 증빙서류 요구로 개선되어야 할 항목으로 분석되었다. 결론: 본 연구를 통해 건설현장의 안전관리비 제도 개선을 위한 문제점을 인식하고, 건설안전관리자에 의한 개선방안을 정책적·제도적인틀속에서 마련되어야 할 것이다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.662-663
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• 2015

Despite the improvement of productivity and cost, the operating of such equipments yet has been recognized as a 3D business which is a low wage and poor working environment business field. Accordingly, the number of such operators has been decreasing by time. Especially, construction equipment demands higher controlling skills and occasionally involved in critical accidents. Therefore, this study aims to suggest a conceptual design for an construction equipment Around View Monitoring system that visually assists the operator for more efficient operating. It is expected that the application of such technology for a construction equipment highly improves the productivity and work quality, moreover, prevents disastrous accidents that occur to labors.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.319-327
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• 2022

Robots for construction sites, although not deeply widespread, are finding applications in the duties of project monitoring, material movement, documentation, security, and simple repetitive construction-related tasks. A significant shortcoming in the use of robots is the complexity involved in programming and re-programming an automation routine. Robotic programming is not an expected skill set of the traditional construction industry professional. Therefore, this research seeks to deliver a low-cost approach toward re-programming that does not involve a programmer's skill set. The researchers in this study examined an approach toward programming a terrestrial-based drone so that it follows a taped path. By doing so, if an alternative path is required, programmers would not be needed to re-program any part of the automated routine. Changing the path of the drone simply requires removing the tape and placing a different path - ideally simplifying the process and quickly allowing practitioners to implement a new automated routine. Python programming scripts were used with a DJI Robomaster EP Core drone, and a terrain navigation assessment was conducted. The study examined the pass/fail rates for a series of trial run over different terrains. The analysis of this data along with video recording for each trial run allowed the researchers to conclude that the accuracy of the tape follow technique was predictable on each of the terrain surfaces. The accuracy and predictability inform a non-coding construction practitioner of the optimal placement of the taped path. This paper further presents limitations and suggestions for some possible extended research options for this study.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.920-927
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• 2009

Many schedule delays and cost overruns in interior construction are caused by a lack of understanding in detailed and complicated interior works. To minimize these potential impacts in interior construction, a systematic approach for project managers to detect discrepancies at early stages and take corrective action through use of visualized data is required. This systematic implementation is still challenging: monitoring is time-consuming due to the significant amount of as-built data that needs to be collected and evaluated; and current interior construction progress reports have visual limitations in providing spatial context and in representing the complexities of interior components. To overcome these issues, this research focuses on visualization and computer vision techniques representing interior construction progress with photographs. The as-planned 3D models and as-built photographs are visualized in a 3D walk-through model. Within such an environment, the as-built interior construction elements are detected through computer vision techniques to automatically extract the progress data linked with Building Information Modeling (BIM). This allows a comparison between the as-planned model and as-built elements to be used for the representation of interior construction progress by superimposing over a 3D environment. This paper presents the process of representing and detecting interior construction components and the results for an ongoing construction project. This paper discusses implementation and future potential enhancement of these techniques in construction.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.324-327
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• 2015

Scaffold is the most commonly used equipment in various types of construction works. Since various types of construction works use the same scaffold equipment, it becomes more difficult to be controlled and managed, thus resulting hazard frequently. According to the information announced in July 2012 by Council of Labor Affairs Executive Yan, the site collapse or incomplete anti-falling protection has led the site to accident frequently, and this is the main reason that causes construction industry occupational disasters. The labor death occupational hazard ratio rises up to 13% in scaffold activity, and the Council of Labor Affairs Executive Yan has showed that the death ratio is higher when using the scaffold in construction site, the total number of death has reached to 139 from 2005 to 2010. In order to ensure the safety of scaffold user, this study tends to build a wireless sensor monitoring system to detect the reliability and safety of the scaffold. The wireless sensor technique applies in this study is different with the traditional monitoring technique which is limited with wired monitoring. Wireless sensor technique does not need wire, it just needs to consider the power supply for establishing the network and receiving stable information, and it can become a monitoring system. In addition, this study also integrates strain gauge technique in this scaffold monitoring system, to develop a real-time monitoring data transfer mechanism and replace the traditional wired single project monitoring equipment. This study hopes to build a scaffold collapse monitoring system to effectively monitor the safety of the scaffold as well as provide the timesaving installation, low-cost and portable features.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.202-203
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• 2020

Unlike price calculation by cost accounting, which categorizes costs into material costs, labor costs, and miscellaneous expenses to determine the construction budget price, construction cost calculation based on Construction Standard Unit Prices utilizes unit prices extracted from market prices of items from projects already completed to estimate costs of similar construction projects. Although unit price information is collected through construction site surveys to revise these construction standard unit prices every year, but due to the limitations of the site survey method, it is difficult to quickly implement the rapid changes in the construction methods and market prices. As such, an important issue that arose was the identification of work items whose prices need urgent revision. This study conducted research on factors that need to be considered when developing online survey system for monitoring construction site market prices. This study is expected to enhance convenience for users, and provide an efficient data collection and management system for administrators.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.50-51
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• 2014

Although price of construction equipment affects overall cost of a construction projects, the cycle of updating them presented in the Poom-Saem in Korea is more than six years. Recently there is a demand of using the 'Standard Market Price of Construction Equipment', published by the ministry of Security and Public Administration, for estimating equipment operating and ownership cost. It is urgent to introduce an advanced system for updating the prices which can timely reflect market changes.

• 한국건설관리학회논문집
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• 제8권5호
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• pp.191-200
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• 2007

This paper introduces a tool for predicting potential cost overrun during project execution and for quantifying the uncertainty on the expected project cost, which is occasionally changed by the unknown effects resulted from project's complications and unforeseen environments. The model proposed in this stuff is useful in diagnosing cost performance as a project progresses and in monitoring the changes of the uncertainty as indicators for a warning signal. This model is intended for the use by project managers who forecast the change of the uncertainty and its magnitude. The paper presents a mathematical approach for modifying the costs of incomplete work packages and project cost, and quantifying reduced uncertainties at a consistent confidence level as actual cost information of an ongoing project is obtained. Furthermore, this approach addresses the effects of actual informed data of completed work packages on the re-estimates of incomplete work packages and describes the impacts on the variation of the uncertainty for the expected project cost incorporating Multivariate Probabilistic Analysis (MPA) and Bayes' Theorem. For the illustration purpose, the Introduced model has employed an example construction project. The results are analyzed to demonstrate the use of the model and illustrate its capabilities.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1196-1202
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• 2007

In construction of high speed railway, the fan shape is limited to achieve reduction of required travel time and concrete railway which has structural stability and induces small maintenance cost with allowable ground settlement is recently applied. So construction of concrete railway on soft ground in which considerable ground settlement occurs increases and settlement management in soft ground section is required. Field monitoring on ground movement and integrated geotechnical information system which manages construction, design, and field monitoring data are essential for settlement management of concrete railway subgrade. Site investigation data are also required due to future repair work. Therefore in this study, integrated geotechnical information system for construction and maintenance of concrete railway is developed. The developed system consists of a database and an application program. The database contains site investigation, construction, design, and field monitoring data throughout a railway. Application program performs various functions on managing and utilizing information in the database with graphic visualization of output. And by providing integrating information with comprehensible visual displays, the applicability and effectiveness of the developed system for construction and maintenance management were confirmed.