• Tunnel and Underground Space
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• v.34 no.4
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• pp.374-392
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• 2024

In order to successfully select a site for deep geological disposal of high-level radioactive waste, it is important to perform the stepwise approach along with the systematic selection and survey of evaluation parameters of geological environmental characteristics suitable for the domestic geological environment. In this study, we evaluated the characteristics of hydraulic conductivity, which is considered the most important evaluation parameter in the field of hydrogeology, targeting a deep-depth rock aquifer where actual disposal facilities are expected to be located. In particular, for the first time in Korea, we obtained in-situ pressure-flow data by directly conducting hydraulic tests in boreholes at depths ranging from 500 m to 750 m in various rock types distributed in Korea (granite/volcanic rock/gneiss/mudstone). And we derived hydraulic conductivity values by rock types and depth using verified analytical methods. For this purpose, precision hydraulic testing equipment developed in-house through this study was used, and detailed investigation procedures based on standard test methods were applied to field tests. As a result of the analysis, the average hydraulic conductivity value was found to be in the range of 10^-9 m/s in all granite/volcanic rock/gneiss areas. In the mudstone area, an average hydraulic conductivity value of 10^-11 m/s was derived, which was about 100 times (2 orders of magnitude) lower than that of the fractured rock aquifers. Moreover, permeability tended to slightly decrease with depth in fractured rock aquifers (granite and volcanic rock areas) containing many rock fractures. The gneiss area tended to have large local differences in permeability according to the composition of the stratum and the development of fracture zones rather than depth. In mudstone areas with weak fracture development, there was no significant variation in rock permeability according to depth. The hydraulic conductivity results by various rock types and depth presented in this study are expected to be utilized in building a foundational database for the site selection, design, and construction of disposal facilities in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1288-1298
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• 2002

To implement elliptic curve cryptosystem in GF(2$\^$m/) at high speed, a fast divider is required. Although bit-parallel architecture is well suited for high speed division operations, elliptic curve cryptosystem requires large m(at least 163) to support a sufficient security. In other words, since the bit-parallel architecture has an area complexity of 0(m$\^$m/), it is not suited for this application. In this paper, we propose a new serial-in serial-out systolic array for computing division operations in GF(2$\^$m/) using the standard basis representation. Based on a modified version of tile binary extended greatest common divisor algorithm, we obtain a new data dependence graph and design an efficient bit-serial systolic divider. The proposed divider has 0(m) time complexity and 0(m) area complexity. If input data come in continuously, the proposed divider can produce division results at a rate of one per m clock cycles, after an initial delay of 5m-2 cycles. Analysis shows that the proposed divider provides a significant reduction in both chip area and computational delay time compared to previously proposed systolic dividers with the same I/O format. Since the proposed divider can perform division operations at high speed with the reduced chip area, it is well suited for division circuit of elliptic curve cryptosystem. Furthermore, since the proposed architecture does not restrict the choice of irreducible polynomial, and has a unidirectional data flow and regularity, it provides a high flexibility and scalability with respect to the field size m.

• Journal of Intelligence and Information Systems
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• v.24 no.3
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• pp.177-198
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• 2018

Recently, as economic property it has become necessary to acquire and utilize the framework for water resource measurement and performance management as the property of water resources changes to hold "public property". To date, the evaluation of water technology has been carried out by feasibility study analysis or technology assessment based on net present value (NPV) or benefit-to-cost (B/C) effect, however it is not yet systemized in terms of valuation models to objectively assess an economic value of technology-based business to receive diffusion and feedback of research outcomes. Therefore, K-water (known as a government-supported public company in Korea) company feels the necessity to establish a technology valuation framework suitable for technical characteristics of water resources fields in charge and verify an exemplified case applied to the technology. The K-water evaluation technology applied to this study, as a public interest goods, can be used as a tool to measure the value and achievement contributed to society and to manage them. Therefore, by calculating the value in which the subject technology contributed to the entire society as a public resource, we make use of it as a basis information for the advertising medium of performance on the influence effect of the benefits or the necessity of cost input, and then secure the legitimacy for large-scale R&D cost input in terms of the characteristics of public technology. Hence, K-water company, one of the public corporation in Korea which deals with public goods of 'water resources', will be able to establish a commercialization strategy for business operation and prepare for a basis for the performance calculation of input R&D cost. In this study, K-water has developed a web-based technology valuation model for public interest type water resources based on the technology evaluation system that is suitable for the characteristics of a technology in water resources fields. In particular, by utilizing the evaluation methodology of the Institute of Advanced Industrial Science and Technology (AIST) in Japan to match the expense items to the expense accounts based on the related benefit items, we proposed the so-called 'K-water's proprietary model' which involves the 'cost-benefit' approach and the FCF (Free Cash Flow), and ultimately led to build a pipeline on the K-water research performance management system and then verify the practical case of a technology related to "desalination". We analyze the embedded design logic and evaluation process of web-based valuation system that reflects characteristics of water resources technology, reference information and database(D/B)-associated logic for each model to calculate public interest-based and profit-based technology values in technology integrated management system. We review the hybrid evaluation module that reflects the quantitative index of the qualitative evaluation indices reflecting the unique characteristics of water resources and the visualized user-interface (UI) of the actual web-based evaluation, which both are appended for calculating the business value based on financial data to the existing web-based technology valuation systems in other fields. K-water's technology valuation model is evaluated by distinguishing between public-interest type and profitable-type water technology. First, evaluation modules in profit-type technology valuation model are designed based on 'profitability of technology'. For example, the technology inventory K-water holds has a number of profit-oriented technologies such as water treatment membranes. On the other hand, the public interest-type technology valuation is designed to evaluate the public-interest oriented technology such as the dam, which reflects the characteristics of public benefits and costs. In order to examine the appropriateness of the cost-benefit based public utility valuation model (i.e. K-water specific technology valuation model) presented in this study, we applied to practical cases from calculation of benefit-to-cost analysis on water resource technology with 20 years of lifetime. In future we will additionally conduct verifying the K-water public utility-based valuation model by each business model which reflects various business environmental characteristics.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.170-174
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• 1997

Constructed wetland system was studied to treat wastewater from industrial complex in rural area. Pilot plant at the Baeksuk Nongkong Danzi in Chunahn-City was used for field study. For the DO, the effluent concentration was higher than the influent concentration and it implies that natural reaeration supplies enough oxygen to the system. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which is consist of soil and plants. For the BOD and COD, the average removal rate of them were 56% and 43%, respectively, therefore, the effluent concentration could not meet water quality standards when influent concentration was high. The removal rate of BOD and COD can be improved by supplemental treatment in addition to this system if necessary. For the T-N and T-P, the influent concentration of them were lower than the water quality standards than no further treatment was needed. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural area. For actual application of this system, further study on design factors including loading rate, removal mechanism, and temperature effects is required to meet water quality standard consistently. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• 대한공업교육학회지
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• v.38 no.1
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• pp.163-194
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• 2013

This study aims at giving examples that can be applied in the real education field, and it develops theme-based integrative education program for Industrial Specialized high school students. It analyzed the models of many scholars about the development of education course, and devised developmental models and procedures of the theme-based integrative education program of engineering specialized high school from those. As a result, it used and reorganized ADDIE model which is the systematic education course development model and the theme-based integrative education development model of Frazee and Rudnitski(1995) as the basic structure, and came to devise theme-based integrative education program of engineering specialized high school while referring to creative engineering design education program development model by Lee Chang-hoon. This study that is theme-based integrative education program for engineering-specialized high school students and is the result of this study has the following characters. First, This theme-based integrative education program that is developed for engineering-specialized high school students can be applied and the initial example that approach the Theme-Based. Second, This Education Program included the Activity project that is "Making Maglev" for the third grade at the engineering-specialized high school and One of the Program's aim is to bring up their attitude that engaged to in the class having the Interest. Third, Theme-based integrative education program for engineering-specialized high school is composed the workbook for the students and the teaching guidance plan for the teachers. Workbook for the students is composed four Units;"Brief about the Maglev","Basic principles about the Maglev","Intensive principles about the Maglev", Activity project about the Maglev". And each unit is made by Learning Purpose, Introducing, Learning Contents(Deepen Learning, Reading Magazines), Assesment etc. Teaching guidance plan for the teachers include that Summary, Purpose, Time Planing & Streaming Map for the class, contents associated Maglev, prerequisite learning, constructure of the education program, flow chart, learning activity, assesment(self-appraiser and peer review).

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.39-53
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• 2007

Generally, fractured medium can be described with some key parameters, such as hydraulic conductivities or random field of hydraulic conductivities (continuum model), spatial and statistical distribution of permeable fractures (discrete fracture network model). Investigating the practical applicability of the well-known conceptual models for the description of groundwater flow in fractured media, various types of hydraulic tests were applied to studies on the highly fractured media in Geumsan, Korea. Results from single-hole packer test show that the horizontal hydraulic conductivities in the permeable media are between $7.67{\times}10^{-10}{\sim}3.16{\times}10^{-6}$ m/sec, with $7.70{\times}10^{-7}$ m/sec arithmetic mean and $2.16{\times}10^{-7}$ m/sec geometric mean. Total number of test interval is 110 at 8 holes. The number of completely impermeable interval is 9, and the low permeable interval - below $1.0{\times}10^{-8}$ m/sec is 14. In other words, most of test intervals are permeable. The vertical distribution of hydraulic conductivities shows apparently the good correlation with the results of flowmeter test. But the results from the cross-hole test show some different features. The results from the cross-hole test are highly related to the connectivity and/or the binary properties of fractured media; permeable and impermeable. From the viewpoint of the connection, the application of the general stochastic approach with a single continuum model may not be appropriate even in the moderately or highly permeable fractured medium. Then, further studies on the investigation method and the analysis procedures should be required for the reasonable and practical design of the conceptual model, with which the binary properties, including permeable/impermeable features, can be described.