• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.93-116
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• 2005

SPT-Uphole tomography method was introducedand verified in this paper. In SPT-Uphole method, SPT (Standard Penetration Test) which is common in site investigation, was used as a source and several surface geophones in line were used as receivers. Shear wave velocity (Vs) distribution map which has triangular shape around the boring point can be obtained by tomography inversion. The factors for obtaining reliable result of SPT-Uphole tomography are exact travel time information and accurate inversion method. To establish of the SPT-Uphole tomography procedure, the most reliable method for obtaining exact travel time information and verification of tomography inversion method were studied by using theoretical travel time information and finite element method (FEM) analysis. finally, SPT-Uphole tomography method was performed at the weathered soil site in Kimje. By comparing with several boring data including SPT-N value, feasibility of this method was verified in the field.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.460-467
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• 2018

Objectives: The objectives of this study are to estimate the inhalation exposure level of benzene for workers using Tier 1 exposure models ECETOC TRA (European Center for Ecotoxicology and Toxicology of Chemicals Target Risk Assessment) and Stoffenmanager, and to investigate their reliability for exposure assessment in K-REACH. Methods: Two exposure scenarios, 'manufacture of benzene' and 'use as solvents,' were developed for assessment of workers' exposure to benzene. The Process Category (PROC) for ECETOC TRA was collected from the European Chemical Agency (ECHA) registration dossier, and the Activity for Stoffenmanager was converted from PROC using translation of exposure models (TREXMO). The information related to exposure, such as working duration, Respiratory Protective Equipment (RPE), Local Exhaust Ventilation (LEV), and Risk Management Measure (RMM) were classified into high, medium, and low exposure conditions. The risk was determined by the ratio of the estimated exposure and occupational exposure limits of benzene. Results: Under high exposure conditions, the worker exposure level calculated from all PROCs and Activities exceeded the risk level, with the exception of PROC 1 and Activity 1. In the medium exposure condition, PROC 8a, 8b, and 9 and Activity 3, 7, and 8 all exceeded the risk, whereas in the low condition, all PROCs and Activities were determined to be safe. As a result, action corresponding with the low exposure condition is required to reduce the risk of exposure among workers in workplaces where benzene is manufactured or used as a solvent. In addition, the predicted exposure levels derived from the exposure models were lower than measured levels. The exposure levels estimated from Stoffenmanager were more conservative than those from ECETOC TRA. Conclusions: This study demonstrates the feasibility of exposure models for exposure assessment through the example of occupational inhalation exposure assessment for benzene. For more active utilization of exposure models in K-REACH, the exact application of collected information and accurate interpretation of obtained results are necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.181-188
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• 2019

The migration path of a multiple-generation technology that occurs during a technological substitution by a new technology is important to understanding the phenomenon of technological substitution, and can contribute to understanding the process of technological innovation. This research defines the concept of migration path and develops a model of the types of migration paths by multiple dimensions (actor, generation, and time) in a multiple-generation technology. Based on a literature review and tracking of migration paths according to multiple dimensions, the definitions and types of migration paths were provided, and the accuracy of the model was verified based on a case study of the semiconductor industry. The migration paths of suppliers are modeled with three types (switching, leapfrogging, and new entrance paths), and the migration paths of customers are modeled with four types (switching, leapfrogging, new entrance, and diffusion paths) in a multiple-generation technology. This research will be useful for understanding the migration paths in the phenomenon of technological substitution, and can be applied to other industries in addition to the semiconductor industry, including various actors. In addition, suppliers and customers can understand technological substitution and can establish a technology strategy against their competitors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.436-445
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• 2019

This study quantitatively evaluates the economic value of an intelligent crime-zero testbed by using the contingent valuation method (CVM), which is the most effective for non-market valuations in fields like crime prevention. To minimize hypothetical convenience and increase respondents' awareness regarding the actual situation, an analysis was conducted for Indukwon District, Anyang City, Gyeonggi-do, by using the intelligent crime prevention technologies and solutions being developed by the KICT Research Center. This analysis was aimed at providing a systematic basis for determining the feasibility of crime prevention-related public projects. As a result, the WTP of Anyang citizens in the intelligent crime prevention demonstration district was estimated to be 7,160 won. The analysis shows that the area of Gwanyang 2, where the test bed belongs, has a high economic value of KRW 660 million per year, and KRW 51.4 billion per year when expanded to Anyang City. This study is significant in that it provides the first domestic evaluation of the crime-zero testbed. In addition, it has academic and practical value for a future-oriented service model by using intelligent crime prevention technologies and solutions that can be applied in real life and to the crime-zero testbed.

• Ocean and Polar Research
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• v.33 no.4
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• pp.473-483
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• 2011

In the recent WTO/DDA negotiations, discussions are progressing to forbid fishery subsidies which have negative effect on the natural environment and the fishery resources and to lower or to eliminate the tariff/non-tariff barriers that distort trade liberalization. As a result, linking to the weak structural environment of Korea's fishing villages; such a scheme has jeopardized the livelihood of fishermen who settle down in local fishing harbors. Against this backdrop, the government is attempting to positively respond to changes in the fishing environment in a number of different ways: promotion of fishing tourism, fishing harbor reinforcement in function, developing fishing villages, and harbors. With respect to investment by priority in fishing harbor development, it is very important to appropriately select investment targets based on objective criteria. A small number of harbors are chosen and investment plans by harbor are systematically devised, economic feasibility and the effects of investment are analyzed and reviewed in relation to each target harbor. This paper is designed to review and assess objective evaluation methods and the degree of importance for the designation of target harbors, dealing with local harbors in Chung Nam Do as a model. Each local government has tried to reorganize existing harbors and develop new harbors, considering a fall in the number of fishing vessels and the expansion of maritime leisure activities. In order to overcome the limit of existing harbors in function, to raise the income of fishermen, and to activate tourism, they have shifted their focus from simple functions such as vessel evacuation and anchoring to harbor beautification, which can work as a basis for fishing tourism. This paper points out that the AHP analysis method for prioritizing local harbors in Chung Nam Do should help to be chosen target harbors in other cities and provinces. Each local government has attempted to reorganize existing harbors and to develop new harbors, taking into consideration the decline in the number of fishing vessels and the expansion of maritime leisure activities. In order to overcome the limited number of functional harbors, to raise the income of fishermen, and to boost tourism, they have shifted their focus from simple functions, such as vessel evacuation and anchoring, to harbor beautification, which can work as a basis for fishing tourism. This paper shows that the AHP analysis method for prioritizing local harbors in Chungcheongnam-do could aid in the effective selection of target harbors in other cities and provinces.

• Tunnel and Underground Space
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• v.28 no.3
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• pp.258-276
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• 2018

The accurate and quantitative ground information on the hydraulic conductivity characteristics of rock mass is one of the key factors for evaluation of the hydro-geological behaviour of rock mass around an excavated opening under high water pressure. For tunnel and rock structures in seabed, where the sea acts as an infinite source of water, its importance become greater with increasing construction depth below sea level. In this study, to improve the problems related with poor system configuration and incorrect data acquisition of previous hydraulic packer testing equipment, we newly developed an integrated main frame and 30 bar level waterproof downhole sonde apparatus, which were optimized for deep hydraulic packer test in seabed rock mass. Integration of individual test equipment into one frame allows safe and efficient field testing work on a narrow offshore drilling platform. For the integrated type main frame, it is possible to make precise stepwise control of downhole net injection pressure at intervals of $2.0kg_f/cm^2$ or less with dual hydraulic oil volume controller. To ensure the system performance and the operational stability of the prototype mainframe and downhole sonde apparatus, the field feasibility tests were completed in two research boreholes, and using the developed apparatus, the REV(Representative Elementary Volume) scale deep hydraulic packer tests were successfully carried out at a borehole located in the basalt region, Jeju. In this paper, the characteristics of the new testing apparatus are briefly introduced and also some results from the laboratory and in-situ performance tests are shown.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.51-58
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• 2016

In the Integrated Two-Phase Anaerobic Digestion (ITPAD) process, acid and methane fermentation take place in one reactor, which has advantages to cope with organic load variation and reduce foot-print required, compensating disadvantages of Conventional Separated Two-Phase Anaerobic Digestion (CSTPAD). In the present work, organic matter degradation efficiency and biogas generation amount and other performance parameters of the ITPAD fed with food waste leachate were analyzed. In addition, feasibility study on the ITPAD method was performed by comparing its digestion efficiency with that of the CSTPAD. Organic matter alteration and biogas generation of the integrated method were examined for approximately 130 days based on the 5ton/day scaled pilot plant. Experiment results revealed that organic matter removal rate was 80% for mean food waste leachate input amount of $4.1m^3/day$. The biogas generation rate was $63.0m^3$ per ton of food waste leachate input, corresponding to the input VS amount of $0.724m^3/kg-VS_{added}$, and methane content of generated biogas was approximately 61.3%. The ITPAD has a comparable or higher organic matter removal efficiency compared to the conventional separated two-phase anaerobic digestion method. Consequently, the ITPAD method has a great need to commercialize a food waste leachate treatment technology against highly concentrated organic waste leachate.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.151-171
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• 2018

Transmission tower-line systems are commonly slender and generally possess a small stiffness and low structural damping. They are prone to impulsive excitations induced by cable rupture and may experience strong vibration. Excessive deformation and vibration of a transmission tower-line system subjected to cable rupture may induce a local destruction and even failure event. A little work has yet been carried out to evaluate the performance of transmission tower-line systems in mountain areas subjected to cable rupture. In addition, the control for cable rupture induced vibration of a transmission tower-line system has not been systematically conducted. In this regard, the dynamic response analysis of a transmission tower-line system in mountain areas subjected to cable rupture is conducted. Furthermore, the feasibility of using viscous fluid dampers to suppress the cable rupture-induced vibration is also investigated. The three dimensional (3D) finite element (FE) model of a transmission tower-line system is first established and the mathematical model of a mountain is developed to describe the equivalent scale and configuration of a mountain. The model of a tower-line-mountain system is developed by taking a real transmission tower-line system constructed in China as an example. The mechanical model for the dynamic interaction between the ground and transmission lines is proposed and the mechanical model of a viscous fluid damper is also presented. The equations of motion of the transmission tower-line system subjected to cable rupture without/with viscous fluid dampers are established. The field measurement is carried out to verify the analytical FE model and determine the damping ratios of the example transmission tower-line system. The dynamic analysis of the tower-line system is carried out to investigate structural performance under cable rupture and the validity of the proposed control approach based on viscous fluid dampers is examined. The made observations demonstrate that cable rupture may induce strong structural vibration and the implementation of viscous fluid dampers with optimal parameters can effectively suppress structural responses.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1388-1393
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• 2000

The present study was conducted to examine the feasibility of utilising bamboo (Bambusa arundinacea) shoot shell (BSS) in ruminants. Chemical composition, rumen degradability and some antinutritional compounds were determined for fresh and boiled BSSs to evaluate its feed value and safety. Thirty-two Holstein heifers were allocated to four groups and used to investigate the response in growth rate to supplementing ammoniated rice straw with fresh shell (phase 1) or silage of boiled BSS (phase 2). All animals were offered ammoniated straw ad libitum with 1kg of cotton seed meal (phase 1) or 0.5 kg of cotton seed meal and 0.5 kg of concentrate mixture (phase 2) per head per day. The BSS was supplemented at levels of 0, 3, 6 or 9 kg/d (phase 1) and 0, 5, 10 or 15 kg/d (phase 2) (as fed basis). The BSS was very high in moisture content, and its contents of crude protein and neutral detergent fiber were 13~16% DM and 65~76% DM, respectively; boiling resulting in higher moisture and protein. No hydrocyanic acid was detected in both BSSs and content of tannins was negligible. Rumen degradability of BSS was reasonably high, and with boiling the rapidly degradable fraction decreased, and potentially degradable component increased. Silage of the boiled BSS was slightly lower in both rapidly and slowly degraded fractions than the fresh BSS. Animals consumed all supplemented BSSs without any adverse health problems. Intake of ammoniated straw decreased with the increasing levels of BSS, but total intake was higher in almost all supplementary groups than in the non-BSS. Heifers had a higher growth rate in phase 1 with fresh BSS than in phase 2 with ensiled shell, and daily weight gains were 622, 629, 744 or 690 g in phase 1, and 578, 575, 677 or 635 g in phase 2 at four BSS levels, respectively. For both phases growth rate was significantly higher for the animals in groups 3 and 4 than those in groups 1 and 2 (p<0.01), with little difference between groups 1 and 2 (p>0.05) but significant difference between groups 3 and 4 (p<0.05). Supplementation with BSS also resulted in an improved feed conversion rate, with the least concentrate consumption in group 3 for both phases. It is concluded that the BSS has a high potential nutritional value as indicated by its medium protein content, reasonably high rumen degradability, and that inclusion of BSS in ammoniated rice straw diet is not only safe to animals, but also may improve growth rate of ruminants and feed conversion rate. It may be disadvantageous to use high amounts of BSS in ammoniated straw diets.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1075-1086
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• 2008

In order to investigate the applicability and suitability of the industrial by-products to apply mono-layer cover system for non-sanitary landfill sites, 6 different industrial by-products, such as construction waste, bottom ash, gypsum, blast furnace and steel manufacture slags, and stone powder sludge, were evaluated. Various physicochemical and hydrodynamic properties of the industrial byproducts were investigated. The environmental safety was monitored using batch and long-term leaching tests as well. In addition, the flexibility of plants was observed by cultivating them in the industrial by-products. The results for physicochemical properties indicate that most of the materials considered appeared to be suitable for landfill cover. Particularly, the concentration levels of hazardous elements regulated by the Korean Law for Waste Management did not exceed the regulatory limits in all target materials. In addition, the concentrations of regulated elements for the Korean Soil Conservation Law were examined below the regulatory limits in most of materials considered, except for the stone powder sludge. The results of batch and long-term experiments showed bottom ash and construction waste were the most suitable materials for landfill cover among the industrial by-products considered. The results of plant studies indicate that the bottom ash among industrial by-products considered was most effective in developing vegetation on landfill site, showing fast germination and large growth index. At the final covering system made of mixture of soil and bottom ash, the optimum application rate of farmyard manure was observed to be 40-50 Mg/ha.