• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.461-465
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• 2010

The objective of this study is to calculate road user costs that caused by the expansion work of metropolitan arterial highway and to analyze the costs that affect economic feasibility evaluation. "Taerung~Guri IC" section of Bukbu Expressway was selected as a case study. As a result, it shows that these costs could be a factor for determining economic feasibility for some projects. However, decreased capacity and free-flow speed are seriously different as period, type, length and traffic volume of work zones. These factors that decrease traffic capacity and free-flow speed should be deeply researched in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.1-4
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• 2007

This study investigated the applicability of insulation curing method with double layer bubble sheets to the man concrete subjected to cold weather. Temperature history of the mass concrete indicated that the highest temperature of center section was exhibited at $34^{\circ}C$ while the that of surface section was $25^{\circ}C$. Difference between center and surface was shown to be less $10^{\circ}C$ when the temperature of center section was peak section, and thereby associated temperature cracking index was calculated 1.5, and occurrence probability of temperature cracking was 5%, so there was no temperature cracking caused by internal restraint. No temperature crack was observed by naked eye. It was clear that early frost demage and temperature cracking could be restrained due to reducing temperature difference between inner part and outside in the case double bubble sheets applied to insulation curing method in cold weather. The maturity of mass concrete is higher than outside about $72\sim89^{\circ}$ DD, so it was demonstrated to prevent early frost demage and ensure strength excellently. Insulation curing method with double bubble sheets was more economic than heating curing method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.703-713
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• 2015

The linking system between the control system and the field devices in the existing EMS/SCADA, in order to increase the reliability of the data, and access control through the separation of external network. Currently, There is a tendency that the need for connection to an external network that takes into account the economic aspect, systematic management and efficiency of operations is increasing. Such is evolved linkage section, is to have more security vulnerabilities than in the past, Eventually communication EMS/SCADA linkage section requires special management method. In this paper, taking into account the domestic environment, were presented the security Certification and Accreditation technology that was applied to serial DNP3 and TCP/IP based DNP3 that are mainly used in EMS/SCADA linkage section. Presented to security of Certification and Accreditation technology, divided into Resource Robustness Test and Malicious Packet Test for evaluate the safety. Each of the security requirements and evaluation method in proposed technology, is an attempt to present the differentiation of the existing Certification and Accreditation technology.

• Economic Analysis
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• v.17 no.4
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• pp.30-51
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• 2011

Since the previous studies on the effects of trade liberalization implicitly assume that trade liberalization affects economic performance only in any point in time, they inevitably are static. Static evaluations fail to account for cumulative dynamic effects of trade liberalization that affect continuously economic performance. This paper tries to fill this gap of the previous studies in this field, estimating cumulative effects of trade liberalization on economic performance by employing an dynamic version of empirical model. One of important empirical issue is controlling bias from endogeneity. To resolve this problem, this paper employes system GMM that uses lagged first-differences as instruments for level equations and lagged levels as instruments for first-differences equations. It improves upon cross-section estimators because it controls for the potential bias induced by the omission of industry-specific effects and the endogeneity of all regressors. This study investigates the effects of trade liberalization in Korean manufacturing for the period from 1988 to 2005 and finds that cumulative dynamic effects of trade liberalization are present and bigger than static effects.

• Journal of Navigation and Port Research
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• v.32 no.1
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• pp.47-56
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• 2008

With rapid growing of the Northeastern Asia, the interest for the connection of Infrastructure that was behind of interesting until now is getting larger. In a line of same connection, UN-ESCAP are forwarding transcontinental railway project, asian highway project et al.. And this study aimed at analysis on the effect that extended to a space by Korea-Japan undersea tunnel project. In aspect of a national land balanced-development to solve various problems such as overcrowding in capital region, unbalanced state by regions, weak exchange between South and North Korea, and weakness of national land basis to prepare for unification et al., this study consulted the economic potentiality model as a analysis method to examine an effect. In this analysis, I used 24 scenarios including all cases by combination of 3 scenarios for Korea-Japan undersea tunnel, 4 scenarios for transportation modes in the section of undersea tunnel, and 2 scenarios for adjacency infrastructure. Transportation modes in the section of undersea tunnel are railway, car-train, mixing way of railway and car-train, and mixing way of road and railway. Adjacency infrastructure applied railway and road. In all scenarios, Korea showed higher growth potentiality than Japan. Also, proposal plan C route relatively showed better in national land balanced-development than other proposal plans. The growth potentiality relatively appeared higher by buildup of a connection together with non-capital regions from the construction of Korea-Japan undersea tunnel. In aspect of Northeastern Asia, it resulted in a increasing of trade and chance of network formation in the region of Asia through infrastructure connection. But, in considering passenger and various factors that extended to the economic growth, this analysis have some limitation. Therefore, I hope that deep studies will continuously perform with various factors.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.7-13
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• 2010

For swiftness and economic feasibility of parcel delivery, optimal location of mail exchanging centers considering not only section delivery distance but also some weights like the number of delivery vehicles are necessary. In this paper, a mechanism with section delivery distance and vehicle number for locating of mail distribution centers which connect some mail centers of major cities in Republic Korea by applying GOSST theory is proposed. This mechanism for locating mail exchange centers can make the total delivery distance of postal matters less than not only present method which assigns Daejun as mail exchange center, but also Steiner tree method which does not consider weights like number of delivery vehicles. The mechanism is good for protecting the environment as well as rapid and economic delivery. In experiment, the proposed mechanism could curtail total delivery distance by 2.52 percentages compared with Steiner tree method and by 6.66 percentages compared with present method. The mechanism may be used in electric power transmission routing, distribution line topology design, power relay station locating where various voltages and other weights should be considered.

• Economic and Environmental Geology
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• v.29 no.3
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• pp.335-343
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• 1996

The dipole-dipol electrical resistivity survey was conducted to investigate the probable contamination of the Han river by leachate from the near-by Nanjido Landfill. The survey line of 3 km was set along the unpaved road toward the Han river. For the convenience of the field work, the survey line was divided into four segments. The complete two-dimensional resistivity section was constructed by connecting the inversion result of each segment. Gravity survey was also carried out along the profile parallel to the resistivity line. Near surface resistivity generally appeared to be of very low value in most part of the survey area and the boundary between the alluvium layer and underlying basement rocks is well discriminated on the resistivity section. These results agree well with those of the preceding Schlumberger depth sounding made at adjacent area by Lee and fun (1995). The variation of thickness of the alluvium layer delineated by gravity anomaly profile also correlates well with the result of the resistivity survey on the qualitative basis. The problem of contamination by leachate from the Nanjido Landfill, where various waste materials have been dumped without any proper treatment facilities, has been remains unsolved yet. Therefore, we present the most probable passages of leachate flow based on the survey results and have briefly discussed about measure for contamination control. Considering the thickness of alluvium and the possible existence of fractured zone, the middle point between 1st and 2nd landfill and the midst of 1st landfill are the most hazardous regions to make leachates flow into the Han river. Since large amounts of leachates are observed from the test wells located on the lines extending from the border between the 1st and 2nd landfill and the middle of the lst landfill, contamination protection barriers are strongly recommended near these regions.

• Computers and Concrete
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• v.29 no.6
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• pp.375-391
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• 2022

This paper examined the impact of the cross-sectional structure on the structural results under different loading conditions of reinforced concrete (RC) members' management limited in Carbon Fiber Reinforced Polymers (CFRP). The mechanical properties of CFRC was investigated, then, totally 32 samples were examined. Test parameters included the cross-sectional shape as square, rectangular and circular with two various aspect rates and loading statues. The loading involved concentrated loading, eccentric loading with a ratio of 0.46 to 0.6 and pure bending. The results of the test revealed that the CFRP increased ductility and load during concentrated processing. A cross sectional shape from 23 to 44 percent was increased in load capacity and from 250 to 350 percent increase in axial deformation in rectangular and circular sections respectively, affecting greatly the accomplishment of load capacity and ductility of the concentrated members. Two Artificial Intelligence Models as Extreme Learning Machine (ELM) and Particle Swarm Optimization (PSO) were used to estimating the tensile and flexural strength of specimen. On the basis of the performance from RMSE and RSQR, C-Shape CFRC was greater tensile and flexural strength than any other FRP composite design. Because of the mechanical anchorage into the matrix, C-shaped CFRCC was noted to have greater fiber-matrix interfacial adhesive strength. However, with the increase of the aspect ratio and fiber volume fraction, the compressive strength of CFRCC was reduced. This possibly was due to the fact that during the blending of each fiber, the volume of air input was increased. In addition, by adding silica fumed to composites, the tensile and flexural strength of CFRCC is greatly improved.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.13-13
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• 2011

The Rio Grande Compact Commission, in collaboration with local water management entities, water users and universities established a three state Rio Grande The Rio Grande Compact Commission, in collaboration with local water management entities, water users and universities established a three state Rio Grande Salinity Management Program. The objectives of the Rio Grande Project Salinity Management Program are to reduce salinity concentrations, loading, and salinity impacts in the Rio Grande basin for the 270 mile river reach from San Acacia, New Mexico to Fort Quitman, Texasto increase usable water supplies for agricultural, urban, and environmental purposes. The focus of this first phase of the program is the development of baseline salinity and hydrologic information and a preliminary assessment of the economic impacts of salinity. An assessment of the economic impacts of salinity in this region was conducted by scientists at Texas A&M University's AgriLife Research Center at El Paso and New Mexico State University. Economic damages attributable to high salinity of Rio Grandewater were estimated for residential, agricultural, municipal, and industrial uses. The major impact issues addressed were: who is being affected the types of economic impacts the magnitude of economic damages overall and by user category and identification of threshold-effect levels for different types of water use. Salinity concentrations in this 270 mile reach of the river typically range from 480 ppm to 1,200 ppm, but can exceed 3,000 ppm in the lower section of this reach. Economic impacts include reductions in agricultural yields, reduced water appliance life, equipment replacement costs, and increased water supply costs. This preliminary economic assessment indicates annual damages of $10.5 million from increased water salinity. Under current water uses, municipal and industrial uses account for 75% of the total estimated impacts. However, agricultural impacts are based on current crop pattern yield reductions and, salinity leaching requirements and do not account for the impacts of reduced revenue from having to grow salinity tolerant, lower value crops. Actual damages are anticipated to be significantly higher with the inclusion of these additional agricultural impacts plus the future impacts from the growing population in the region. A more comprehensive economic analysis is planned for the second phase of this program. Results of the economic analysis are being used to determine the feasiblity of salinity control alternatives and what salinity reduction control measures will be pursued.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.1-8
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• 2023

At construction sites, interest in the production of precast materials is increasing due to off-site conditions due to changes in construction site conditions due to increased labor costs and the Act on the Punishment of Serious Accidents. In particular, the precast prestressed hollow slab has a hollow shape in the cross section, so structural performance is secured by reducing weight and controlling deflection through stranded wires. With the application of structural standards, the urgency of securing fire resistance performance is emerging. In this study, a fire-resistance cross section was developed by reducing the concrete filling rate in the cross section and improving the upper and lower flange shapes by optimizing the hollow shape in the cross section of the slab to have the same or better structural performance and economic efficiency compared to the existing hollow slab. The PC hollow slab to which this was applied was subjected to a two-hour fire resistance test using the cross-sectional thickness as a variable, and as a result of the test, fire resistance performance (load bearing capacity, heat shielding property, flame retardance property) was secured. Based on the experimental results, it is determined that fire resistance modeling can be established through numerical analysis simulation, and prediction of fire resistance analysis is possible according to the change of the cross-sectional shape in the future.