• The Korean Journal of Ecology
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• v.18 no.2
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• pp.285-293
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• 1995

The relationships among the contents of Pb, Zn, Cd, Cu and microbial biomass and activity of soil were investigated in Kyongbu, Yongdong, and Chungbu highways. The heavy metal concentrations were the highest in Kyongbu highway with high traffic density. The levels of these metals in soil in three highway sites were much higher than Mt. Kwank as control site. The highest concentrations of heavy metals were found in the upper layer of soil adjacent to the roadside. Dehydrogenase activity (DHA) and adenosine tri-phosphate (ATP) contents were generally lowest at distance of 0.5 m from the roadside. Simple regression analysis indicated that DHA and ATP contents were highly negatively correlated with Pb and Zn concentrations.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.77-82
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• 2016

PURPOSES : This paper proposes a reliability index for the safety evaluation of freeway sections. It establishes a reliability index as a safety surrogate on freeways considering speeds and speed dispersions. METHODS : We collated values of design elements including radii, curve lengths, vertical slopes (absolute values), superelevations, and vertical slopes from seven freeway sections in Korea. We also collected data about driving speeds, traffic accidents, and their deviations. We established a reliability index using these variables. RESULTS : The average radii, curve lengths, and superelevations are highly correlated with the incidence of traffic accidents. Deviations in radius and curve lengths show an especially high correlation. The reliability index, derived from speed and speed dispersions of the seven freeway sections, also correlated highly with accidents with a correlation index of 0.63. CONCLUSIONS : Since the reliability index obtained from speed and speed dispersions are highly correlated with traffic accidents, we conclude that a reliability index can be a safety surrogate on freeways considering speeds and speed dispersions together in terms of design and operational levels.

• The Journal of Information Systems
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• v.29 no.3
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• pp.103-117
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• 2020

Purpose Recently, various issues related to toxic comments on web portal sites and SNS are becoming a major social problem. Toxic comments can threaten Internet users in the type of defamation, personal attacks, and invasion of privacy. Over past few years, academia and industry have been conducting research in various ways to solve this problem. The purpose of this study is to develop the deep learning modeling for toxic comments classification. Design/methodology/approach This study analyzed 7,878 internet news comments through CNN classification modeling based on Highway Network and OOV process. Findings The bias and hate expressions of toxic comments were classified into three classes, and achieved 67.49% of the weighted f1 score. In terms of weighted f1 score performance level, this was superior to approximate 50~60% of the previous studies.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.129-136
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• 2014

PURPOSES : This study devotes its energies to estimate greenhouse gas emissions for types of horizontal highway designs. METHODS : This paper suggested two types of road scenarios, scenario 1 is made by the lack of road design consistency. Beside scenario 1, scenario 2 is made by good road design. For comparisons of greenhouse gas emissions, driving simulator was used. RESULTS : Emission rates of road scenario 1 are 1.4 times higher than scenario 2 in the driving simulator. CONCLUSIONS : This study may have important implications for contributing to the application of road alignment technology for reduction of greenhouse gases as quantifying the correlations between greenhouse emissions and various road alignments. Consequently, this study will help road designers determine which roads are best alternatives in the process of choosing the roads in the future in terms of environmental benefits.

• Structural Engineering and Mechanics
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• v.31 no.5
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• pp.527-544
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• 2009

In this study, the periodic seismic performance evaluation scheme is proposed using a structural health monitoring system in terms of seismic fragility. An instrumented highway bridge is used to demonstrate the evaluation procedure involving (1) measuring ambient vibration of a bridge under general vehicle loadings, (2) identifying modal parameters from the measured acceleration data by applying output-only modal identification method, (3) updating a preliminary finite element model (obtained from structural design drawings) with the identified modal parameters using real-coded genetic algorithm, (4) analyzing nonlinear response time histories of the structure under earthquake excitations, and finally (5) developing fragility curves represented by a log-normal distribution function using maximum likelihood estimation. It is found that the seismic fragility of a highway bridge can be updated using extracted modal parameters and can also be monitored further by utilizing the instrumented structural health monitoring system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.261-268
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• 2001

Highway bridges are important infrastructures for national transportation systems. However, due to overweight trucks frequently moving on highways, highway structures have been gradually damaged and economical loss has grown severe. To maintain a highway bridge safe and sound, properties and loading characteristics of passing trucks on the bridge must be evaluated WIM(Weigh-In-Motion) systems have been developed by many research groups for multiple purposes. Most of the developed WIM systems have applied moment influence lines to identify loading characteristics. Since passing trucks are dynamic loads, however, the identified loads by the influence lines for static loads cannot represent the actual situation correctly. The current research investigates the effects of problem of different loading characteristics on load identification and proposes a new algorithm using the concept of moment influence surface. A numerical simulation study is carried out.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.87-94
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• 1995

In highway bridges robust damage detection exercises are mandatory to secure the safety of the structures from hostile environmental conditions such as fatigue earthquake, wind, and corrosion. This paper presents a damage detection practice in a full-scale highway bridge by utilizing modal response parameters of as-built and damaged states of the structure. first the test structure is described and modal testing procedures are outlined. Next, a damage detection model which yields information on the location of damage directly from changes in mode shapes is outlined. Finally, the damage detection model is implemented to predict the location of damage in the ten structure. From the results, it was found that the damage detection model accurately locates damage in the test structures for which modal parameters of only a single mode are available for pre-damage (as-built) and post-damage stages.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.8-14
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• 1997

The dynamic responses of highway bridges are varying depending on the features of either traveling vehicles or bridges. In this study, the probabilistic characteristics of dynamic amplification factors of highway bridges due to traveling heavy vehicles have been examined through analytical simulation processes. The truck with tandem axle and tractor with semitrailer are selected as the representative heavy vehicles, which are modeled with three dimensional 7-DOF and 12-DOF models, respectively. The analytical results have been compared with the experimental results of dynamic loading tests and the validity of the analytical models has been examined. Parametric studies on the means and extreme values of amplification factors have been performed with various traffic conditions such as vehicle types, vehicle weights, surface profiles, vehicle velocity, etc.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.1-6
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• 2002

Korea is a small country with relatively large mountainous areas and has many difficulties from planning to completing one road. Maintaining a completed road presents even more difficulties. presently, in estimating design elements, the result varies according to the engineer and there are many cases that question the reliability of the results. Therefore, in this study, the alignment of highway was sampled using by the centerline path, the design elements of horizontal alignment were reduced by applying the Least Squares Method, and the accuracy was analyzed. By this method, IP, IA, R, $\Delta$R and A-parameter were also determined. By observing relatively long straight sections, the approximate values could be estimated, and particularly, the considerably accurate value of A-parameter was determined. This study, using the Least Squares Method, aims to contribute to the development of the alignment examination in frequent traffic accident regions.

• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.125-152
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• 1995

The purposes of this study are twofold ; (1) to investigate the accuracy of estimation power of the individual models. such as those of Highway Capacity Nanual (HCM), Korea Highway Capacity Manual (KHCM), and NationalCooperative Highway Research Program(NCHRP) Report339 ; and (2) to develop an adjusted delay model which can be applied to the signal control system in urban areas. The study is mainly focused on four subjects related to the research purposes, which are as follows ; (1) characteristecs of exsisting delay models ; (2) inherent problems in exsisting delay models : (3) validation of the proposed model by the comparison of observed delay with estimated delay :and (4) a method which can be applied to develop an appropriate delay model for actrual signal control systems by the adjusted fact of the proposed model.