• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.240-248
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• 1999

On the basis of data obtained from five forest roads collapsed due to a heavy rainfall of 1995 in Chunchon, Kangwon-do, this study was carried out to evaluate and predict the fill slope failure of forest roads with four factors of forest road structure and those of location condition by using Quantification theory(II). The results were summarized as follows ; In the structure factors of forest road, the fill slope failure was mainly occurred in longitudinal gradients less than $2^{\circ}$ or more than $4^{\circ}$, distance of surface-flow longer than 80m, fill slope length greater than 6m, and fill slope gradients steeper than $35^{\circ}$. In the factors of location condition, the failure was mainly occurred in ridge portion of road position, weathered rock and soft rock of constituent material, slope gradients in the range from $35^{\circ}$ to $45^{\circ}$, and concave and convex of longitudinal slope forms. The priority order for factors influencing on fill slope failure was ranked by fill slope length, constituent material, road position, and so on. And the rate of correct discrimination by analysis of fill slope failure was estimated at the high prediction of 86.5%.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.73-81
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• 2013

PURPOSES : In this study, various laboratory tests were performed to investigate basic physical properties of the asphalt concrete which uses wasted vinyl aggregates. METHODS : The thermal conductivity, ultrasonic velocity, Marshall stability, flow, indirect tensile strength were measured according to binder content and wasted vinyl aggregate content. An experimental construction was performed to verify construct ability of the asphalt pavement using the wasted vinyl aggregates. RESULTS : The thermal conductivity and ultrasonic velocity decreased showing insulation effect by mixing more wasted vinyl aggregate, whereas stability and flow increased. The void ratio shows similar value regardless of the mixing ratio. The highest indirect tensile strength was measured at 2.5% of wasted vinyl aggregate content. The construct ability was verified by observing the process of mixing, placing, and compaction and the state of the pavement surface. CONCLUSIONS : The basic properties and construct ability of the asphalt concrete using the wasted vinyl aggregates were verified. The temperature according to pavement depth will be measured to verify the insulation effect of the wasted vinyl aggregates. In addition, amount of snowfall, snowmelt area, and ice adhesion strength will be analyzed quantitively.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.633-636
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• 2004

Airborne laser scanning thechnology has been studied in many applications, DSM(Digital Surface Model) development, building extraction, 3D virtual city modeling. In this paper, we will evaluate the possibility of airborne laser scanning technology for transportation application, especially for recognizing moving vehicles on road. First, we initially segment the region of roads from all LiDAR DATA using the GIS map and intensity image. Secondly, the segmented region is divided into the roads and vehicles using the height threshold value of local based window. Finally, the vehicles will be classified into the several types of vehicles by MDC(Minimum Distance Classification) method using the vehicle's geometry information, height, length, width, etc

• Journal of the Korean Society of Industry Convergence
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• v.4 no.3
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• pp.339-347
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• 2001

Automatic automobile has been studied as the alternative energy system and the production flow automation device recently. But this is dependent on the import production, and its position cannot be controlled free from the fixed path. It is difficult to control the automobile position because of the eccentricity of inertia monent, slip and roughness between wheel and road surface. This problems is solved for the controller to be feedbacked the data of the multi-sensor system consisting of the rotary encoder and electronic compass. The proportional Integrated controller in the modified Ziegler-Nichols method is made up with Hitachi 7034 microprocessor. To the real time control the mechanical, electrical and electronic hardware and software device is produced by myself. The RF data of automobile speed and position is supplied to the remote PC to be displayed the automobile condition. By the experinent of the forward, spin, point path planning, it is known for autombile.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.413-417
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• 2007

노면배수 시설의 설계를 위하여 부등류 해석을 기반으로 한 설계모형을 수립하고 등류 해석을 기반으로 한 설계결과와 비교하였다. 노면배수시설을 설계하기 위해서는 지속시간을 가정하여 설계강우를 결정하고 설계변수인 유출구 간격을 가정하여, 호우에 응답하여 발생하는 홍수의 도달시간이 가정된 지속시간과 유사할 때까지 계산을 반복하여 유출구 간격을 결정한다. 부등류 해석에 의한 수로 흐름 해석은 수로 양단에 유출구를 갖는 수로의 분수계의 위치를 결정하는 과정과 발생하는 최대수심이 허용수심을 초과하지 않도록 수로길이를 산정하는 과정을 포함하므로 등류 해석에 비해 계산과정이 복잡하게 된다. 가상의 노면배수 체계를 설정하고 다양한 수로경사에 대해 노면배수 설계모형을 적용한 결과, 등류해석의 경우 유출구 간격은 수로경사가 증가할수록 증가하였지만, 부등류 해석의 경우 수로경사가 증가할수록 감소하였다가 다시 증가하는 경향을 보였다. 수로경사가 작은 경우 등류 해석보다 부등류 해석을 기반으로 노면배수 시설을 설계하는 것이 합리적인 것으로 판단되었다.

• Elastomers and Composites
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• v.58 no.2
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• pp.81-86
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• 2023

Asphalt pavements are generally composed of fine and coarse aggregates, bitumen, and modifier. Asphalt pavement wear particles (APWPs) are produced by friction between the road surface and the tire tread, and they flow into the environment such as rivers and oceans. Model APWPs were prepared and a single APWP of 212-500 (S-APWP) and 500-1000 ㎛ (L-APWP) was analyzed using thermogravimetric analysis (TGA) to investigate inhomogeneity in the compositions of the APWPs. The reference TGA thermogram was built using thermograms of the raw materials and formulation of the model asphalt pavement. The compositions of the APWPs were different from each other. Ash contents of the APWPs were lower than expected. Inhomogeneity in the total contents of bitumen and modifier was more severe than that in the other components. The inhomogeneity of the S-APWPs was more severe than that of the L-APWPs.

• Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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• 2003.05a
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• pp.20-20
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• 2003

In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

• New & Renewable Energy
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• v.9 no.1
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• pp.6-11
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• 2013

Jeollabuk-do has announced a future plan for the Saemangeum Wind Farm which includes the installation of fourteen wind turbines in a single line, located 500m back from the Saemangeum Seawall. It is anticipated as a positive effect that, for sea breeze blowing toward land, the average wind speed could be accelerated and the wind speed distribution could be uniformized by dint of the seawall, an upstream structure of the turbines. At the same time it is also anticipated as a negative effect that the strength of wind turbulence could be increased due to the flow separation generated at the back end of the seawall. According to the results of the computational fluid dynamics analysis of this paper, it has been observed that, at the 50m zone on the road surface located at the uppermost part of the Saemangeum Seawall, the average wind speed has been accelerated by approximately 6~7% and that wind shear has been decreased by 70%, but this positive effect disappears in the zone situated beyond the 100m from the back end of the seawall. It has also been observed that flow separation exists to a limited extent only below the bottom of the blade-sweeping circle and, furthermore, does not extend very far downstream of the wind. As a conclusion, it can be said that the seawall neither positively nor negatively affects the proposed Saemangeum Seawall Wind Farm layout.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.55-68
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• 2012

Impervious surface increase due to urbanization, one of the leading causes of pavement increased the runoff coefficient, peak flow, and reducing the infiltration flow and thereby causing flooding and river erosion is occurring in aquatic ecosystems are known to impair. This study aimed to classify use type of detailed land into the road, reststop, tollgates and etc. focused on major domestic highways, to understand the characteristics of rainfall runoff pollutants and to calculate applicable unit pollution load. Because of high runoff coefficient and short travel time to drainage. first flush occurred clearly. Average EMCs of runoff in the highway was investigated as TSS 108.47 mg / L, COD 28.16 mg / L, BOD 13.61 mg / L, TN 6.38 mg / L, TP 0.03 mg / L, Cu 118.17 ${\mu}g$ / L, Pb 345.3 ${\mu}g$ / L, Zn 349.47 ${\mu}g$ / L. Unit pollution loads calculated by detailed land use area of highways based on average annual rainfall, EMCs, applicable basin areas and etc. were 46.6 kg/km2/day of BOD, 1.4 kg/km2/day of TP, 8.81 kg / km2/day of TN and these were BOD 50.8%, TP 66.7%, TN 64.4%in comparison of the unit pollution loads which applies fallow land standards of the TMDL(Total Maximum Daily Load). It was considered that discharged loads can be excessively calculated in case highway non-point management plans based on unit pollution load of the current land standard.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.930-934
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• 2006

In this study, we conducted water-quality analysis of wastewater and in-situ flow measurement using automatic flow rate measuring instrument to identify characteristics of wastewater in urban areas, and collected samples in gutter fur storm water drain, rainfall bucket, and aqueduct of pipe from roof, and outfalls of basins to examine the contribution by pollution origins such as base wastewater, atmospheric washing, runoff by roof surface, runoff by road surface, erosion of sewer sediment. In the result, the concentration of pollutants reached peak in the beginning of rainfall due to first flush, was 3 to 10 times higher than average concentration of dry period, and was lower than that of dry period due to dilution of storm water. In the analysis of the contribution by pollution origins, the ratio of load by sewer sediment resuspension to the total pollution load was 54.6% fer COD, and 73.3% fur SS. Accordingly, we can reduce the total pollutant load by periodical dredging and washing of sewer sediment, and control the loadings by overflow of combined sewer overflows.