• International conference on construction engineering and project management
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• 2005.10a
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• pp.974-979
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• 2005

Effective communication flow is a fundamental for the success of any construction projects. The key role of communications among project parties is even more critical in the case of Design-Build (DB) projects. Previous research has shown that these projects have an environment where integration between different project team members and schedule constraints increase channels of communication, and require faster communication flows. This paper summarizes the findings from research analyzing organizational structures and communication flow of the Texas State Highway 130 (SH130) project. Awarded in 2002, the SH130 project, totaling $1.3 billion USD, constitutes the "pilot" application for the DB approach in the state of Texas. A set of observations pertaining to team organization and communication issues in the design-build environment is included.

• 도로교통
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• s.71
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• pp.58-66
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• 1997

• Nuclear industry
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• v.16 no.9 s.163
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• pp.82-83
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• 1996

• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.46-55
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• 2020

The maintenance cost for highway pavement is gradually increasing due to the continuous increase in road extension as well as increase in the number of old routes that have passed the public period. As a result, there is a need for a method of minimizing costs through preventative grievance Preventive maintenance requires the establishment of a strategic plan through accurate prediction old Highway pavement. herefore, in this study, the XGBoost among machine learning classification-based models was used to develop a highway pavement damage prediction model. First, we solved the imbalanced data issue through data sampling, then developed a predictive model using the XGBoost. This predictive model was evaluated through performance indicators such as accuracy and F1 score. As a result, the over-sampling method showed the best performance result. On the other hand, the main variables affecting road damage were calculated in the order of the number of years of service, ESAL, and the number of days below the minimum temperature -2 degrees Celsius. If the performance of the prediction model is improved through more data accumulation and detailed data pre-processing in the future, it is expected that more accurate prediction of maintenance-required sections will be possible. In addition, it is expected to be used as important basic information for estimating the highway pavement maintenance budget in the future.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.283-292
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• 2013

The objective of this research is to evaluate of global and local damage for steel-concrete composite structures under highway bridge exposed to fire loading. To enhance the accuracy and efficiency of the numerical analysis, the proposed transient nonlinear thermal structure interaction(TSI) parallel fire analysis method is implemented in ANSYS. To validate the TSI parallel fire analysis method, a comparison is made with the standard fire test results. The proposed TSI parallel fire analysis method is applied to fire damage analysis and performance evaluation for Buchen highway bridge. The result of analysis, temperature of low flange and web are exceed the critical temperature. The deflection and deformation state show good agreement with the fire accident of buchen highway bridge.

• International Journal of Highway Engineering
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• v.16 no.4
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• pp.75-86
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• 2014

PURPOSES: The aim of this paper is developing user-oriented flexible Level Of Service (LOS) system for integrated asset management of various road facilities. It is essential to overcome limitations of general management systems which only focus on a type of assets (e.g. pavement, bridge etc.), and to serve a customizable LOS platform for smooth implementation and future improvement of the LOS considering various managerial environments of road agencies. METHODS: This study suggested a total framework of the LOS system as a process for self-development, operation and improvement of LOS system to conduct the PDCA (Plan-Do-Check-Act) in management process. In the process, we adopted user-customizable elements regarding asset definition, service index and evaluation method to match with the managerial environment of road agencies. In addition, we conducted an empirical study on the entire process of the suggested LOS system with a real road agency (Korea Express Highway) to prove applicability of the LOS system. RESULTS: From the empirical study, we confirmed that the suggested LOS system framework were suitable for development of customized LOS system. In addition, evaluation of asset conditions by LOS ratings, and quantification of vision achievement of the Korea Express Highway were successfully made. It would be the first trial in integrated management approach with LOS systems for numerous road facilities. CONCLUSIONS : It was recognized that easy application and sustainable improvement of the LOS was the most critical point in asset management. The suggested LOS system would be a powerful weapon as a managerial tool in preparing tight budget, aging infrastructures, and increased demands for more accountability both in Korea and internationally. Implementation of the LOS system needs to be expanded to the other infrastructure members to serve satisfactory level of service to taxpayers.

• Land and Housing Review
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• v.2 no.2
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• pp.171-182
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• 2011

Current state of population, the existing roads, and the function of roads and highways of North Korea have been reviewed in this paper. In addition, the 'Five by five' road network has proposed for North-South and East-West directions to be connected with the road network of South Korea, China, and Asian Highways. Furthermore, the evaluation criteria and weighted values have suggested to determine the investment priority of highway based on the survey results from expert group members using AHP analysis method. Throughout the analysis, the ranking of the investment priority has been decided for the North-South axis and East-West axis. The second North-South axis (Geasung-Pyungyang-Anju-China) has been ranked as the first priority for the North-South axis followed by the fifth North-South axis as the second, the first axis as the third, the third axis as the fourth and the fourth axis as the last priority. For the East-West axis, the second East-West axis(Nampo-Pyungyang-Wonsan) has been ranked as the first priority followed by the first axis as the second, the third axis as the third, the fourth axis as the fourth and the fifth East-West axis as the last priority.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.207-214
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• 2005

The reflected signals from the defects of a pile and the boundaries between the pile and soils are analyzed to evaluate the integrity of drilled shafts in the impact-echo test. Signals varied according to both of the stiffness ratio of the pile to defects and that of the pile to surrounding soils. Model tests using the small size pile in the laboratory and numerical analyses have limitations in finding the characteristics of the signals due to different stress wave characteristics and unreliable modelling for the interaction between the pile and soils respectively. Full scale testing piles which have artificial defects are installed by the actual construction method and they were used to investigate the characteristics of reflected signals according to defects and the stiffness ratios of the pile to soils around.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.389-396
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• 2013

Objective: The ride qualities of the six passenger cars were evaluated in 4 subjects on the highway and uneven road. The relation between vibration with driving velocity and driving posture were also investigated separately. Background: Ride comfort plays an important role in the vehicle design. Vibration is the one of the principal components associated with ride comfort. Method: The acceleration of the foot, hip and back were measured using B&K accelerometers in this study. The velocity of the passenger cars was maintained at a constant speed of 80km/h on the highway and 40km/h on the uneven road. For evaluating the effects of driving velocity and driving posture on vehicle's vibration level, separate experiments were performed on the highway with 5 different vehicle speeds and 5 different backrest angles, respectively. Results: The overall ride value of the luxury car showed the best result while the smaller car showed the worst value on the highway. On the uneven road the overall ride value level was increased 75~98%. All the vehicles had the SEAT value less than 1. Faster the velocity lowers the SEAT value. The ride quality in terms of vibration gets worst when the backrest angle increased. Conclusion: The smaller car had a first mode at the higher frequency and showed higher vibration level. SEAT value was mostly affected by the seat property not by vehicle. We ranked the luxury car seat had a best vibration reduction quality than others based on SEAT values. When the driving velocity increased, the overall ride values were increased proportionally and the SEAT values were somewhat decreased. Application: Evaluation of whole-body vibration in the passenger car.

• Parasites, Hosts and Diseases
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• v.58 no.2
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• pp.191-194
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• 2020

Free-living amoebas (FLAs) can cause severe disease in humans and animals when they become infected. However, there are no accurate survey reports on the prevalence of FLAs in Korea. In this study, we collected 163 tap water samples from buildings, apartments, and restrooms of highway service areas in 7 Korean provinces with high population density. All these buildings and facilities have water storage tanks in common. The survey was separated into categories of buildings, apartments, and highway service areas. Five hundred milliliters of tap water from each building was collected and filtered with 0.2 ㎛ pore filter paper. The filters were incubated in agar plates with heated E. coli at 25℃. After axenization, genomic DNA was collected from each FLA, and species classification was performed using partial 18S-rDNA PCR-sequencing analysis. We found that 12.9% of tap water from buildings with storage tanks in Korea was contaminated with FLAs. The highway service areas had the highest contamination rate at 33.3%. All of the FLAs, except one, were genetically similar to Vermamoeba vermiformis (Hartmannella vermiformis). The remaining FLA (KFA21) was very similar to Acanthamoeba lugdunensis (KA/E26). Although cases of human infection by V. vermiformis are very rare, we must pay attention to the fact that one-third of tap water supplies in highway service areas have been contaminated.