• Journal of the Korean GEO-environmental Society
• /
• v.10 no.5
• /
• pp.41-47
• /
• 2009

In this paper, the long-term performance of highway embankment using tire shred-sandy soil mixture as a lightweight fill material was evaluated through the field monitoring and field test programs. A tire shred-sandy soil embankment was constructed to support a four-lane highway in Indiana, which was built with a 50 : 50 volumetric ratio of tire shreds (maximum particle dimension of 76 mm) and sandy soil (SP, USCS). After opening of the road for traffic, no noticeable differential settlement and lateral deformation were observed, and no adverse environmental impact on temperature was detected as a result of the construction of the tire shred-sandy soil embankment. Moreover, FWD test results showed that tire shred-sandy soil mixture provides bearing capacity comparable to that of conventional fill and meets the criterion for a design life of 20 years.

• Asian Journal of Atmospheric Environment
• /
• v.8 no.4
• /
• pp.202-211
• /
• 2014

In this study, long-term rainfall data with irregular spatial distribution in Seoul, Korea, were separated into individual precipitation events by the inter-event time definition of 6 hours. Precipitation washout of $PM_{10}$ and $NO_2$ concentrations in the air considering various complex factors were analyzed quantitatively. Concentrations of $PM_{10}$ and $NO_2$ in the atmosphere were lower under condition of rainfall compared to that of non-precipitation, and a noticeable difference in average $PM_{10}$ concentrations was observed. The reduction of concentrations of $PM_{10}$ and $NO_2$ by rainfall monitored at road-side air monitoring sites was also lower than that of urban air monitoring sites due to continuous pollutant emissions by transportation sources. Meanwhile, a relatively smaller reduction of average $PM_{10}$ concentration in the atmosphere was observed under conditions of light rainfall below 1 mm, presumably because the impact of pollutant emission was higher than that of precipitation scavenging effect, whereas an obvious reduction of pollutants was shown under conditions of rainfall greater than 1 mm. A log-shaped regression equation was most suitable for the expression of pollutant reduction by precipitation amount. In urban areas, a lower correlation between precipitation and reduction of $NO_2$ concentration was also observed due to the mobile emission effect.

• Journal of Advanced Navigation Technology
• /
• v.23 no.6
• /
• pp.548-553
• /
• 2019

Along with advanced vehicle to vehicle (V2V) communication technologies, platooning is regarded as one of the most promising form of autonomous driving solutions in order to increase road capacity. In this paper, we propose a novel V2V transmission scheme for safety message dissemination in platooning. The proposed scheme enhances the efficiency of channel access and multi-vehicle orthogonal frequency division multiple access (OFDMA) transmission by taking advantage of triggered uplink access technique and null data packet feedback report protocol introduced in the sixth generation WLAN standard, IEEE 802.11ax. The simulation results prove that the proposed scheme outperforms the conventional IEEE 802.11 transmission scheme throughout all measured vehicle density range.

• Journal of IKEEE
• /
• v.24 no.3
• /
• pp.821-827
• /
• 2020

In particular, vehicles with internal combustion engines of public transportation such as diesel and CNG buses are in urgent need of measures to reduce emissions as they have a long daily total mileage, long driving hours and a large number of vehicles. In this paper, the fuel consumption rate (km/kWh) was actually measured through road test of electric buses. Based on the measured values, CO₂ emissions from internal combustion engines and electric buses were calculated per bus. In addition to environmental improvement effects such as the expected reduction of carbon dioxide compared to CNG buses when replacing city buses with electric buses, additional effects were analyzed when the replacement of CNG buses is expanded to electric buses.

• Journal of the Korean Applied Science and Technology
• /
• v.29 no.4
• /
• pp.561-569
• /
• 2012

Study attempts to evaluate the environmental cost and benefit for management of particulate matters of Donghae harbor in Gangwondo. The level of fine dust suspended in the vicinity of the harbor was quite high, exceeding the national standard ($100{\mu}g/m^3$) depending on the places. The test field harbor deals with lots of limestone and coal, so that fine particulates could be generated while loading it and unloading. It was estimated that the direct handling of cargos might produce 12 tons of PM10(Particulate Matters of $10{\mu}m$) a year. In addition, heavy vehicles for transportation of various cargos including raw materials emit huge amount of diesel soots and cause to redispersion of road dust. The local government spends more than 2 billion won every year, and it contributes to reduce the atmospheric dust. According to the prediction of cost to benefit, it will present the effectiveness in 720 % maximum and at least 240 %.

• Journal of Distribution Science
• /
• v.14 no.10
• /
• pp.59-72
• /
• 2016

Purpose - This study expands the corporate social responsibility (CSR) model and concepts by adding to it the concepts of corporate identity and public existence responsibility. Then, this study examines the structural relationship between corporate identity and public existence responsibility. This study contributes to expanding CSR to give customers a different perspective from previous studies in that it specifically measures corporate public existence responsibility, corporate identity, and corporate value creation and investigates the structural relationship. Research design, data, and methodology - This study addresses specific research questions. First, it asks whether non-financial performance is a component of CSR; second, it asks if the improvement in the corporate image should be treated as its corporate identity; and third, it tries to expand CSR concepts from corporate citizenship and public market awareness to public existence responsibility. The research hypothesis is formulated to confirm the relationships among CSR, corporate value creation, corporate identity, and public existence responsibility. Result - This study confirms that CSR has a positive correlation with corporate value creation and that CSR has a relatively positive correlation with corporate identity and public existence responsibility. Additionally, it confirms a positive correlation between corporate identity and public existence responsibility. However, corporate identity and public existence responsibility do not have an effect on corporate value creation. However, the influence of public existence responsibility confirmed the influence of corporate value creation through corporate identity as a mediating variable. Conclusion - This study argues that CSR produces more general performance including both financial and non-financial performance. It also confirms that the goals and performance of CSR can substitute for corporate value creation from general performance. It further confirms that public existence responsibility includes market public awareness, corporate images, and corporate associations. It suggests that corporations should see themselves as having public existence responsibility. Further, they should devise strategies to build corporate identities that associate with corporate goals and visions. Finally, this study contributes to the expansion of perspectives on CSR theoretical concepts and goals of performance of the corporation throughout the corporate value creation process.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.16 no.3
• /
• pp.91-102
• /
• 2013

The purpose of this study is to suggest the way of effective use of spatial data in Busan metropolitan city. To do so, information systems and spatial data established in each department are analyzed. Spatial data distribution networks scattered around the nation are integrated to the national spatial information clearinghouse and the service is expanded for the public and the private sectors to participate. Information systems supplied by the central government are 22 and information systems operating in the Busan Metropolitan City are 168. In addition, there are also 295 types of the thematic maps in 11 fields related to the environment, road transportation, livestock, and etc. For systems integration and management system, an integrated information management and linkage system is required in the near future. In the next logical step, generation of metadata, experiments for effective utilization of spatial data, and construction of the data center should be necessary.

• 도로교통
• /
• s.97
• /
• pp.14-27
• /
• 2004

도로에 있어 교통량이 일정한 수준을 초과하여 증가되는 경우 통행시간과 운행비용이 과도하게 증대되는 혼잡현상이 발생하게 된다. 이러한 혼잡은 경제적 관점에서 추가분의 통행자가 기존 이용자의 통행비용을 증가시키는 유형으로 해석되고 있고, 이에 대한 대응으로 많이 사용되어 왔던 방법이 개별 통행자에게 다른 이용자들의 통행비용 증가분에 상응하는 요금을 혼잡통행료로서 부과하는 방법이다. 이와 같은 혼잡통행료는 국내의 경우 도심부로 진입하는 특정 도로에 국한하여 시행되는 것을 일반적인 것으로 인식하고 시행해왔으나(서울시 남산1, 3호 터널) 국외의 경우에는 환경보호 및 수요조절 측면에서 고속도로까지 확대 시행하고 있는 사례를 찾아볼 수 있다. 이에 본 연구에서는 국내의 고속도로 요금체계 현황에서 혼잡 통행료의 도입방안 및 가능성을 검토하고자 한다. 고속도로의 현행 통행료 부과 방법 및 제도를 고려할 때 통행요금에 혼잡통행료를 도입할 경우 1)시간대별 차등요금제, 2)폐쇄식 및 개방식 구간에서의 차등요금제, 3)노선별, 구간별 차등요금제, 4)요일별, 계절별 차등요금제를 고려할 수 있다. 현재의 고속도로에서 혼잡통행료를 도입할 경우 현행 이부요금제의 주행요금에 혼잡통행료 개념을 도입하는 것이 타당할 것으로 검토된다. 시간대별 차등요금제는 그 시간대를 주간(06시~24시)과 야간(24시~06시)으로 구분함이 타당할 것으로 판단되고 폐쇄식 구간의 경우 혼잡도를 고려한 주행요금을 이용거리에 비례하여 부과하며 개방식 구간의 경우 최단 이용거리를 기준으로 혼잡도를 고려한 주행요금을 부과하는 것이 타당할 것으로 판단된다. 또한 혼잡도를 고려한 주행요금을 부과하는데 있어 노선별, 구간별 차등을 두는 것이 바람직할 것으로 기대된다. 그러나 요일별 차등요금제는 주 5일 근무제가 확산됨에 따라 증가하는 비업무 승용차의 통행에 의해 고속도로의 비효율적인 운영이 발생할 경우를 제외하고는 적용하지 않는 것이 타당할 것으로 검토된다.

• International Journal of Highway Engineering
• /
• v.4 no.3 s.13
• /
• pp.1-13
• /
• 2002

Design methods for new flexible pavements and overlays are in the transition from empirical to mechanistic approach, and many state highway agencies trend to move toward the adoption and use of mechanistic-empirical (M-E) design in new constructions and rehabilitations of flexible pavements. Hence, the Michigan Department of Transportation (MDOT) decided to develop a M-E flexible pavement design procedure, in which major pavement distresses such as fatigue cracking and rutting are employed as indicators of the serviceability of a flexible pavement. The main concept of the developed design procedure is that a designed pavement that is supposed to carry a certain number of traffic must satisfy designated thresholds of rut depths and fatigue lives during a service period. For the M-E design procedure, transfer functions were developed to predict rut-depths and fatigue lives. These functions related the pavement responses to pavement performance. For validation, three current new flexible pavement design cases were obtained from the MDOT. In these cases, asphalt concrete (AC) layer thicknesses determined by the suggested M-E procedure compare favorably with those determined by the current MDOT design practice that is based on AASHTO design guide. This finding implies that the suggested Michigan M-E flexible pavement design procedure can provide a good opportunity to improve the current design practice.

• International Journal of Highway Engineering
• /
• v.17 no.5
• /
• pp.25-31
• /
• 2015

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.