간행물
한국도로학회논문집 KCI 등재 International journal of highway engineering
- 발행기관 한국도로학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1738-7159 (Print)2287-3678 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 토목공학 공학 분류의 다른 간행물
- 십진분류KDC 534DDC 625
권호리스트/논문검색
제17권 제5호 (2015년 10월) 15건
1.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : A finite difference model considering snow melting process on porous asphalt pavement was derived on the basis of heat transfer and mass transfer theories. The derived model can be applied to predict the region where black-ice develops, as well as to predict temperature profile of pavement systems where a de-icing system is installed. In addition, the model can be used to determined the minimum energy required to melt the ice formed on the pavement.
METHODS : The snow on the porous asphalt pavement, whose porosity must be considered in thermal analysis, is divided into several layers such as dry snow layer, saturated snow layer, water+pavement surface, pavement surface, and sublayer. The mass balance and heat balance equations are derived to describe conductive, convective, radiative, and latent transfer of heat and mass in each layer. The finite differential method is used to implement the derived equations, boundary conditions, and the testing method to determine the thermal properties are suggested for each layer.
RESULTS: The finite differential equations that describe the icing and deicing on pavements are derived, and we have presented them in our work. The framework to develop a temperature-forecasting model is successfully created.
CONCLUSIONS : We conclude by successfully creating framework for the finite difference model based on the heat and mass transfer theories. To complete implementation, laboratory tests required to be performed.
4,000원
2.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to develop a deicing pavement system using carbon fiber or graphite with high electrical conductivity and thermal conductivity.
METHODS: Based on literature reviews, in general, conventional concrete does not exhibit electrical and thermal conductivity. In order to achieve a new physical property, experiments were conducted by adding graphite and carbon fiber to a mortar specimen.
RESULTS: The result of the laboratory experiment indicates that the addition of graphite can significantly reduce the compressive strength and improve the thermal conductivity of concrete. In the case of carbon fiber, however, the compressive strength of the concrete is slightly increased, whereas, the thermal conductivity is slightly decreased against the plain mortar irrespective of the length of the carbon fiber. In addition, a mixture of the graphite and carbon fiber can greatly improve the degree of heating test.
CONCLUSIONS : Various properties of cement mortar change with the use of carbon fiber or graphite. To enhance the conductivity of concrete for deicing during winter, both carbon fiber and graphite are required to be used simultaneously.
4,000원
3.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : The noise, which is typically generated by fast moving vehicles, can be intercepted by installing a noise barrier with a soundproof panel. However, reflections from the panels cause secondary noise, and hence lower the effectiveness of the panels. In this study, the reduction of reflection noise by considering the shape, especially zigzag one, of the soundproof panel have been evaluated.
METHODS : The simulation model used in this study was Nord2000, which simulates real-road situations effectively. Based on the simulation results, the joining angle of 133。with the pattern width (a) equal to 2 m and the projection height (b) equal to 0.5 m was adapted in the zigzag shape as the best profit designing factors.
RESULTS: The measuring results at middle height, 15 m showed reduction at all points except the point with average -1.6 dB. At a greater height of 30 m, 2 points showed reduction. A real-sized facility was constructed to investigate the reflected sound from a zigzag shaped panel up to the height of 5 m.
CONCLUSIONS: The reduction effects were detected in all the receive points in the range of 2-6 m distances and 1-5 m heights comparing the plane panel. Compared to plane panel, the noises are reduced at an average of 2.4 dBA.
4,000원
4.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to analyze the relationship between the FWD back-calculated modulus and dynamic modulus of asphalt layers for existing asphalt pavements.
METHODS: To evaluate the dynamic modulus of the asphalt mixture in the existing and new asphalt layers, the uniaxial direct tension test was conducted on small asphalt specimens obtained from the existing asphalt-covered pavements. A dynamic modulus master curve was estimated by using the uniaxial direct tension test for each asphalt layer. The falling weight deflectometer (FWD) testing was conducted on the test sections, and the modulus values of pavement layers were back-calculated using the genetic algorithm and the finite element method based back-calculation program. The relationship between measured and back-calculated asphalt layer moduli was examined in this study. The normalized dynamic modulus was adopted to predict the stiffness characteristics of asphalt layers more accurately.
RESULTS: From this study, we can conclude that there is no close relationship between dynamic modulus of first layer and back-calculated asphalt modulus. The dynamic moduli of second and third asphalt layers have some relation with asphalt stiffness. Test results also showed that the normalized dynamic modulus of the asphalt mixture is closely related to the FWD back-calculated modulus with 0.73 of R square value.
CONCLUSIONS: The back-calculated modulus of asphalt layer can be used as an indicator of the stiffness characteristics of asphalt layers in the asphalt-covered pavements.
4,000원
5.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this paper is to investigate the application of thermoelectric technology to concrete structures for harvesting solar energy that would otherwise be wasted. In various fields of research, thermoelectric technology using a thermoelectric module is being investigated for utilizing solar energy.
METHODS: In our experiment, a halogen lamp was used to produce heat energy instead of the solar heat. A data logger was used to record the generated voltage over time from the thermoelectric module mounted on a concrete specimen. In order to increase the efficiency of energy harvesting, various factors such as color, architecture, and the ability to prevent heat absorption by the concrete surface were investigated for the placement of the thermoelectric module.
RESULTS : The thermoelectric module produced a voltage using the temperature difference between the lower and upper sides of the module. When the concrete specimen was coated with an aluminum foil, a high electric power was measured. In addition, for the power generated at low temperatures, it was confirmed that the voltage was generated steadily.
CONCLUSIONS: Thermoelectric technology for energy harvesting can be applied to concrete structures for generating electric power. The generated electricity can be used to power sensors used in structure monitoring in the future.
4,000원
6.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: The operational characteristics of roundabouts are generally influenced by location as well as traffic volume. The goal of this study is to develop urban and rural roundabout accident models and to discuss safety improvement guidelines based on the model.
METHODS : To analyze accidents, count data models are utilized in this study. This study used accident data from 2010 to 2013 for 56 roundabouts collected from the Traffic Accident Analysis System (TASS) of Road Traffic Authority. Poisson and negative binomial regression models were developed for this study using NLOGIT 4.0.
RESULTS : The main results are as follows. First, the hypotheses that there are distributional differences in the number of accidents and injuries/fatalities among rural and urban roundabouts were accepted. Second, Poisson and negative binomial regression accident models, which were all statistically significant, were developed. Seven independent variables, which were statistically significant, were adopted. Third, the common variable of models was evaluated to be traffic volume.
CONCLUSIONS : This study developed two negative binomial roundabout accident models and suggested some accident reduction strategies. The results are expected to give some implications to the safety improvement of roundabout.
4,000원
7.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: The purpose of this study is to estimate the impact of variable message signage (VMS) on traffic safety as a function of road curve radius using statistical methods.
METHODS: In order to analyze the impact of VMS installations on traffic safety, travel speed, lateral distance, and geometric data relating to road curvature in each study area was acquired and analyzed for the impact of providing VMS information on driver performance and traffic safety using statistical methods including student t-test, Mann-Whitney test, and the Anderson-Darling test for estimating traffic safety hazard zone in each lane.
RESULTS: As a result of analyzing driver performance characteristics before and after providing VMS information, it was determined that by providing VMS information, mean travel speed is deceased and vehicles are driven with increased precision, following the centerline in the first and second lanes. Also the results of analyzing traffic safety impacts of VMS indicate that traffic safety performance factors in the first lane of the Gapyeong section can, on average, increase in the left and right side of the lane by 19.22% and 68.98%, respectively, and in the case of the second lane, safety impacts, on average, can increase in both sides by 100%. For the Hongcheon section, traffic safety impacts in the first lane, on average, can increase along the left and right sides of the lane by 32.31% and 47.18%, and within the second lane, traffic safety can be increased along the left and right side of the lane by 10.97% and -0.01%, respectively.
CONCLUSIONS: Based on the results of this study, the impact on traffic safety obtained by providing VMS information for road sections with smaller curve radii is greater than can be obtained for road sections with larger curve radii.
4,000원
8.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: Nighttime driving is very different from daytime driving because drivers must obtain nighttime sight-distances based on road lights and headlights. Unfortunately, nighttime driving conditions in Korea are far from ideal due to poor lighting and an insufficient number of road lights and inadequate operation and maintenance of delineators. This study is conducted to develop new standards for nighttime road visibility based on experiments of driver perception for nighttime visibility conditions.
METHODS : In the study, perception level and satisfaction of nighttime visibility were investigated. A total of 60 drivers participated, including 34 older drivers and 31 young drivers. To evaluate driver perceptions of nighttime road visibility, fuzzy set theory was used because the conventional analysis methods for driver perception are limited in effectiveness for considering the characteristics of perception which are subjective and vague, and are generally expressed in terms of linguistic terminologies rather than numerical parameters.
RESULTS : This study found that levels of nighttime visibility, as perceived by drivers, are remarkably similar to their satisfactions in different nighttime driving conditions with a log-function relationship. Older drivers evaluated unambiguously degree of nighttime visibility but evaluations by young drivers regarding it were unclear.
CONCLUSIONS : A minimum value of brightness on roads was established as YUX 30, based on final analyzed results. In other words, road lights should be installed and operated to obtain more than YUX 30 brightness for the safety and comfort of nighttime driving.
4,000원
9.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study was conducted to derive the optimum mixing ratio of phosphorescent pigment for the development of phosphorescent line marking.
METHODS: In this study, we utilized a literature review and case study methodology, to describe the domestic and foreign state of practice for the production and mixing of phosphorescent pigment for use in line marking. The optimal mixing ratio was derived by comparing the reduction in luminance over time for the various phosphorescent pigment mixing ratios identified in the literature. In addition, performance and construction characteristics were analyzed using field testing techniques.
RESULTS : The results were as follows: 1) the results of the luminance performance standards tests showed that all of the phosphorescence test specimens satisfied the phosphorescent fire protection standard. As the phosphorescent pigment mixing ratio increased, the luminance value increased, 2) the luminance reduction rate was minimum at the mixing ratio of 50%. However, when compared to a mixing ratio 40%, a small difference was recorded, the luminance reduction rate from the mixing ratio of 40% is judged as being converged. Therefore, in view of the economic efficiency, it was determined that the optimal mixing ratio was 40%, 3) as a result of construction on the field, a mixing ratio of 40% was found to have a higher luminance value than the general line marking for up to three hours after sunset, 4) it was found that the phosphorescent line markings without glass beads spraying had a higher luminance value than the phosphorescent line markings with glass beads spraying.
CONCLUSIONS : Through the results of the basic experiments of the line markings obtained by blending a phosphorescent pigment, the results could be applied to play an important role in the development of phosphorescent line marking paint technology and in establishing application planning for on-site construction characteristics.
4,000원
10.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : In link matching using vehicular trajectory in a car navigation system, it is technically difficult to match the location of the subject vehicle with a link on an electronic map in the vehicle on a grade separation highway segment consisting of an elevated highway and atgrade highway, because of the overlap of geometric lines of the two highways. This study was initiated to propose a link matching algorithm using the characteristics of vehicular movement of the subject vehicle.
METHODS : The selected test site is the highway segment between Jeong-reung IC and Gil-eum IC where the Inner Circulation Road and Jeong-reung-ro run together. To evaluate the proposed algorithm, this study collected the raw packet data of vehicles that drove on the test site. In a simulation environment, link matching was performed using an existing algorithm as well as the proposed algorithm.
RESULTS: It was clearly found that the characteristics of vehicular movements are different on the two highways.
CONCLUSIONS: The proposed algorithm outperformed the existing algorithm.
4,000원
11.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : Traffic accidents and damage due to speeding should be recognized as a problem which harms society and the economy as well as the parties to the accidents. It is time to seek more detailed and concrete customized alternatives than the existing policies for the prevention of traffic accidents.
METHODS: In this study, we identified the characteristics driver behavior and psychological factors that lead to speeding, and a study was carried out to verify the causality models developed from the factors we identified.
RESULTS : Driving behavior variables have a significant effect on speeding behaviors in order of Lapse, Violation, and Mistake. And the violation which is defined as intentional violation showed the result which supports the research hypothesis as it has the significant effect on speeding intention and behaviors.
CONCLUSIONS: The result of this study can be utilized to develop educational problems concerning speeding and previous response with the main objective of eliminating speeding driver behavior.
4,000원
12.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to present a linear programing optimization model for the design of lane-based lane-uses and signal timings for an isolated intersection.
METHODS: For the optimization model, a set of constraints for lane-uses and signal settings are identified to ensure feasibility and safety of traffic flow. Three types of objective functions are introduced for optimizing lane-uses and signal operation, including 1) flow ratio minimization of a dual-ring signal control system, 2) cycle length minimization, and 3) capacity maximization.
RESULTS : The three types of model were evaluated in terms of minimizing delay time. From the experimental results, the flow ratio minimization model proved to be more effective in reducing delay time than cycle length minimization and capacity maximization models and provided reasonable cycle lengths located between those of other two models.
CONCLUSIONS : It was concluded that the flow ratio minimization objective function is the proper one to implement for lane-uses and signal settings optimization to reduce delay time for signalized intersections.
4,200원
13.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: The aim of this study is to analyze and compare the operational effectiveness and safety of three different types of roundabout found in the literatures using a VISSIM and SSAM program.
METHODS : The three types roundabout tested are the 2-lane roundabout (2R), the Turbo roundabout (TR), and the Flower roundabout (FR). For each scenario, three roundabout types and traffic conditions such as traffic volume and movement ratio were applied to VISSIM in order to compute the average delays. In addition the total conflict was calculated through SSAM by using trajectory data from VISSIM.
RESULTS: From the analysis results, the average delay in TR and FR type was higher than the 2R. Regardless of the roundabout types, the average delay was reduced as the right-turn vehicles increased. The total conflict in TR was fewer than 2R for all traffic conditions.
CONCLUSIONS : The results of this study can be used in the planning and design process of roundabout deployment. The data also provides some numerical justifications in transition from at-grade intersection to roundabout.
4,000원
14.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES: Recently, many local governments have applied chicanes for traffic calming to ensure environment-friendly comfortable and safe roads. However, the geometry of a chicane is designed for speed reduction using a curved portion. This study aims to improve the road geometry conditions of chicanes for reducing carbon emissions and maintaining appropriate driving speeds by considering the relationship between road geometry and carbon emissions.
METHODS: This study was conducted as follows. First, carbon emissions corresponding to changing acceleration of vehicles were studied. Second, vehicle acceleration caused by the relationship between the curve radius and the straight length was studied. Accordingly, desirable conditions of curve radius and length of the straight section for reducing carbon emissions were proposed.
RESULTS: The existing literature on chicanes present the minimum value of stagger length and path angle in the primary variable condition. This study suggests the maximum values of the curve radius and length of straight section in the primary variable condition. Therefore, if a vehicle’s speed at a chicane is 30 km/h, this study suggests a curve radius of up to 24 m. In addition, if the vehicle’s speed is 24 km/h, this study suggests a length of straight section of up to 6.6 m. These are the geometric conditions for considering the control of acceleration to the vehicle’s maximum speed.
CONCLUSIONS: This paper proposes an application of geometric conditions to reduce carbon emissions and maintain appropriate speeds of vehicles through a combination of curve radius and length of straight section.
4,000원
15.
2015.10
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study aimed to develop a new highway capacity estimation method and provide comparative results among traditional capacity estimation methods and the recommended values in the latest version of KHCM.
METHODS : The limitations of the existing methods, such as inconsistency and underestimation of the capacity value, are summarized through an extensive literature review. To overcome these limitations, a new method is introduced by adopting a definition of capacity and traffic flow characteristics at or near breakdown points. This method can produce the capacity value by searching a point corresponding to the maximum traffic flow through analysis of gradient changes (point of inflection) of the traffic flow and speed distribution. Comparative results of capacity values from each method are also presented to validate the new method by using data collected from detectors on freeways.
RESULTS: From the analysis results, it is shown that a consistent capacity value can be estimated by applying the new method. In addition, the resulting capacity values are 3%-4% higher than those recommended in KHCM.
CONCLUSIONS : The capacity values listed in the current KHCM tend to produce underestimated results. The new method presented in this paper may be included in the future edition of KHCM.
4,200원
