• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.164-174
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• 2008

As buildings become larger, higher and more complex in most construction sites, construction projects have to deal with transportation of more materials, labor and equipment, necessitating more use of construction equipment. Notably, in the high-rise building and plant construction projects mobile cranes are adopted more frequently among different types of construction machinery, which also results in serious industrial accidents relating to the use of crane. To reduce serious industrial accidents involving cranes, researches on its stability is in need. The research herein aims to study how to select sling and lug of mobile crane and review its stability. The research outcomes herein will make considerable contributions to selecting mobile cranes efficiently and ensuring their stability.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.98-106
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• 2005

The construction cost index and the forecasting model of apartment house can be efficient for evaluating the validness of the fluctuating price, and for making guidelines for construction firms when calculating their profit. In this study the previous construction cost index of apartment house was improved, and the forecasting model based on X-12 ARIMA was developed. According to the result, during the last five years the construction cost, excluding labor expense, has risen approximately to 22.7%. And during next three years, additional 16.8% rise of construction cost is expected. Those quantitative results can be utilized for evaluating the apartment house's selling price in an indirection, and be helpful to understand the variation pattern of the price.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.103-112
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• 2007

The purpose of this study is to evaluate the characteristics of the structural behavior in precast segmental prestressed concrete girders, which consist of five precast segments. These girders were developed to save labor and cost in construction field reducing a term of work. Therefore, four different types of specimens of 25m in length were built, and they were tested and analyzed for observing flexural behavior. The analysis included the investigation of the flexural behaviors in varying tendon amount and at joints using the relationship between moment and deflection. Moreover, nonlinear finite element analysis was utilized to verify the experimental result.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.11-19
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• 2014

The Construction industry is a labor-intensive industry that its labor cost takes up about 30~40% out of the whole construction cost. However, due to a stereotype that on-site work is a 3D job there is a shortage of the labor forces. Modular construction method is to produce modular units in the plant so that workers could work stably. Also, after delivering the module from plant to the site, there will be only installment to be required that shortens construction duration. Even though the modular market is currently expanding based on military facilities in Korea, its best strengths are not demonstrated well which are shortened construction period and low cost. It also causes labor problem of production due to minimum utilization of the modular construction method. Multi-skilled labor means a technician that is able to perform more than two kinds of work with more than two techniques. Multi-skilled labor can proceed smoothly by figuring out the connectivity between the precedent and following operations. Therefore, this research is to apply the concept of Multi-skilled labors, suggest solutions and allocate manpowers efficiently. As a result, it helps to decrease idle manpowers during the operation and the total labor forces can be saved. Low cost is the original strength of the modular which can stand out so the modular market is expected to expand.

• Korean Journal of Construction Engineering and Management
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• v.1 no.1 s.1
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• pp.87-94
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• 2000

Crack sealing, a routine and necessary part of pavement maintenance, is a dangerous, costly, and labor-intensive operation. Within the North America, about ${\$}200$ million is spent annually on crack sealing, with the Texas Department of Transportation (TxDOT) spending about ${\$}7$ million annually (labor alone accounts for over 50 percent of these costs). Prompted by concerns of safety and cost, the University of Texas at Austin, in cooperation with TxDOT and the Federal Highway Administration (FHWA) has developed a unique computer-guided Automated Road Maintenance Machine (ARMM) for pavement crack sealing. In 1999, successful field tests have been undertaken in 8 States around the U.S. This paper first describes significance of the automated crack sealing and technical advances in automated crack sealers including the ARMM, developed in the U.S. It then discusses the ARMM's field implementation and performance evaluation results, and improvements and modifications suggested through the technology evaluation during the field trials. Current research efforts and future work plans in its further development are also presented in this paper.

• The Korean Journal of Archival Studies
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• no.75
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• pp.41-89
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• 2023

Since the enactment of the Act on the Management of Presidential Archives in 2007, the cases of electronic records transfer in the 16th President Roh Moo-hyun's administration have played the role of an advance guard in managing public records and served as a test bed for new electronic records management. When transferring the electronic records of the 19th President Moon Jae-in's administration, the electronic records transfer method of President Roh's administration was inherited, while several innovative attempts were made. For instance, the Presidential Archives have for the first time converted the electronic documents from institutions advising the President into a long-term preservation package and transferred them online. In addition, considering the characteristics of the data, the administrative information dataset of the Presidential record creation institutions was transferred to the SIARD standard. Furthermore, the Presidential Archives had websites transferred in the form of OVF as a pilot test and collected social media directly through the API. Thus this study investigated the transition process of the presidential electronic records transfers from the 16th President Roh Moo-hyun's administration to the 19th President Moon Jae-in's. In addition, major achievements and issues were analyzed centering on the transfer method by type of electronic records during President Moon Jae-in's administration, and future improvement plans were presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.267-275
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• 2023

As aged infrastructures have been increased, the importance of accurate maintenance costs and proper budget allocation for infrastructure become prominent under limited resources. This study proposed a mapping algorithm between representative defects, repair methods, and the estimated maintenance costs for concrete bridges. In this regard, using BMS (Bridge Management System) data analysis, bridge repair methods were classified and matched with defects according to their locations, types, and sizes. In addition, the maintenance costs were estimated based on the amount of work-load and quantity per unit using CSPR (Cost Standard Production Rate). As a result, the level of accuracy was an average of 85.1 % compared with the actual bill of quantity for Seoul bridge maintenance. The accuracy of maintenance costs is expected to be enhanced by considering the various site conditions such as pier height, extra charge conditions, additional equipment, etc.

• Korean Journal of Construction Engineering and Management
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• v.7 no.3 s.31
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• pp.112-121
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• 2006

The purpose of this study is to execute economical analysis for two types of office building HVAC system using LCC technique : single vs, separated HVAC(equal partition installation, unequal partition installation) system. The research method of this study includes the case analysis and questionnaire surveys. The results of this study are as follows: (1) LCCs of 3 types of HVAC system are estimated and the most economical one is investigated as single HVAC system, (2) In this case study, the single HVAC system was investigated as 34% lower in LCC during 15 years per $100m^2$ compared to equal partition installation, as 41% compared to unequal partition installation.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.579-583
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• 2004

A new and extendable highway should be planned and budgeted by estimating the total construction cost on the basis of the precise cost data. However, the demolition or disjointing cost could not reflect construction site condition sufficiently because it was simply estimated by multiplying the highway structure installation cost by the regular ratio($10\~70\%$) specified in the Korea Standard Estimate. The regular ratio for estimating of demolition and disjointing cost was calculated by not actual construction cost data but subjective experiences of field manager. Therefore, the reliance of the estimated demolition or disjointing cost has been declined. The primary objective of this study is to purpose the standard for estimating proper demolition or disjointing cost of relevant items through various site analysis and survey, and to investigate on the propriety of ratio-unit price method for estimating demolition and disjointing cost.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.237-247
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• 2015

The project management information system (PMIS) has recently been developed by using the information technology(IT) in order to implement advanced information management technology to construction industry in Korea. The PMIS has been applied not only to domestic construction projects, but also to some overseas projects executed by Korean construction companies. This study was performed to develop the PMIS that is tailored to the US construction IT market. It has been monopolized by the US-based IT companies, but other companies are recently emerging with competitive technology and market strategy. As a preceding study, existing commercially available systems were analyzed, and the required features of the PMIS were identified by analyzing the core elements of contract, process and cost management about construction projects in the US. Then, the PMIS was developed based on the aforementioned analysis results. The system includes the document management module with an internal electronic approval system, the cost-plus-based automatic labor cost calculation module, and the progress management module to support the integrated project cost management. In addition, the functionality of the developed system was verified by experts about construction management in the US via questionnaire survey. The developed PMIS, in this study, is expected to be applied not only to the US construction IT market as a system specialized for the US construction industry, but also to other oversea markets in the future.