• Journal of the Korea Computer Industry Society
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• v.8 no.4
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• pp.229-236
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• 2007

A factored form is a sum of products of sums of products, ..., of arbitrary depth. Factoring is the process of deriving a parenthesized form with the smallest number of literals from a two-level form of a logic expression. The factored form is not unique and described as either algebraic or Boolean. A Boolean factored form contains fewer number of literals than an algebraic factored form. In this paper, we present a new method for a Boolean factorization. The key idea is to identify two-cube Boolean subexpressions from given two-level logic expression and to extract divisor/quotient pairs. Then, we derive extended divisor/quotient pairs, where their quotients are not cube-free, from the generated divisor/quotients pairs. We generate quotient/quotient pairs from divisor/quotient pairs and extended divisor/quotient pairs. Using the pairs, we make a matrix to generate Boolean factored form based on a technique of rectangle covering.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.695-703
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• 2015

Acceptance criteria for chemical admixtures of cement concrete were investigated in domestic and international specifications. The reliability was verified for solid content test method of chemical admixture examined statistical analysis by round robin test. The applicability of FT-IR spectroscopy for qualitative measurement of multi-compound chemical admixtures verified. From solid content experimental results, outlier analysed using Cochran, Grubbs and Dickson's Q test. Repeatability and reproducibility standard deviation for solid content results showed 0.25 and 0.098% respectively according to KS A ISO 5725-2 procedure, it can be confirmed reliability of test methods. FT-IR spectrum of liquefied or oven-dried chemical admixtures condition showed big differences. It is needed that the FT-IR analysis is performed on dry material. However there's no difference with the applicability of FT-IR spectroscopy for multi-compound chemical admixtures. So the utility of method analysis could not identify.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.57-64
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• 2012

Since a seismic exceeding design load can result in exposing radioactive material during disposal process of radioactive wastes, the repository should be designed with enough seismic margin. In this paper, a seismic fragility analysis was performed to evaluate the seismic capacity of surface facility structures. According to the analysis results, since inspection & store facility and radioactive waste facility have a rectangle geometry, the seismic capacity was differently presented about 23%~43% according to the axis of structures. The HCLPF capacity of inspection & store facility and radioactive waste facility was 0.52g and 0.93g, respectively. And it was observed that seismic capacity of radioactive waste facility was similar to that of a containment for nuclear power plants.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1188-1193
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• 2004

So far, there have been grossly 3 types of studies on GF(2m) multiplier architecture, such as serial multiplication, array multiplication, and hybrid multiplication. Serial multiplication method was first suggested by Mastrovito (1), to be known as the basic CF(2m) multiplication architecture, and this method was adopted in the array multiplier (2), consuming m times as much resource in parallel to extract m times of speed. In 1999, Paar studied further to get the benefit of both architecture, presenting the hybrid multiplication architecture (3). However, the hybrid architecture has defect that only complex ordo. of finite field should be used. In this paper, we propose a novel approach on developing serial multiplier architecture based on Mastrovito's, by modifying the numerical formula of the polynomial-basis serial multiplication. The proposed multiplier architecture was described and implemented in HDL so that the novel architecture was simulated and verified in the level of hardware as well as software. The implemented GF(2m) multiplier shows t times as fast as the traditional one, if we modularized the numerical expression by t number of parts.

• Korea Real Estate Review
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• v.24 no.1
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• pp.53-62
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• 2014

A test on the significance of style factors which were revealed to be significant in U.S. and U.K. literature is conducted in this study using appraisal-based returns of offices in Korea. Region, size (appraisal value), value-growth propensity (yield gain gap) and leasing conditions (the number of tenants, the length of average leased period and the proportion of key tenant) are included in the analysis model as style factors. The empirical result suggests that firstly core region and large size are significant but they increase risk as well as return contrary to general belief, secondly value propensity significantly decreases risk as well as return as it does in U.S. and U.K., finally the number of tenants among leasing conditions decreases risk as well as return but the length of average leased period and the proportion of key tenant are not significant.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.129-153
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• 2017

Fair Competition policy in aviation field has been discussed since open skies policy began in 1970s. This issue has been also the main topic in the ICAO's Worldwide Air Transport Conference, the Air Transport Symposium, etc. ICAO defines competition as the existent or potential rivalry between two or more operators, carriers or groups, striving for advantages in the same market based on different prices, qualities and services. In a broader sense, the definition includes more various meanings; reasonable, fair, effective, and unrestricted competitions. Nowadays, competition laws and regulations to air transportation have been applied more frequently and the issues varies from antitrust immunity, mergers and alliances, abuse of dominant positions, capacity dumping and predatory pricing, sales and marketing, to airport charges and fees, state aid and loan guarantees. Now, the competition among the airlines or nations in aviation industry is changing to cooperation level. A lot of airlines try to survive by various cooperation methods. Therefore the policy of Korean aviation industry should be developed, taking so-called "the viewpoint of national aviation industry ecosystem" into consideration and Korean government should prepare a policy of fair competition to cope with it. First, in the process of open skies policy with neighboring countries such as China, Japan and the Middle East, it is necessary to apply the fair competition act and prepare laws and regulations to implement it. Second, the standards of effective ownership and control of air transportation business should be reviewed. Third, in preparation for aviation agreements and liberalization, the Korean aviation industry needs to study and review competition and cooperation issues through the analysis of strict aviation market structure for airlines and airport operations. Fourth, it is necessary to create a fair air transportation environment for the development of air transportation and competitiveness through preemptive policies such as the approval of mergers, acquisitions, JV and the ripple effects analysis.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.1
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• pp.25-39
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• 2022

This study was conducted to evaluate the manufacturing process of non-sintered cement for the safe containment of radioactive waste using low level or ultra-low level radioactive waste soil generated from nuclear-decommissioning facilities, clay minerals, and blast furnace slag (BFS) as an industrial by-product recycling and to characterize the products using mineralogical and morphological analyses. A stepwise approach was used: (1) measuring properties of source materials (reactants), such as waste soil, clay minerals, and BFS, (2) manufacturing the non-sintered cement for the containment of radioactive waste using source materials and deducing the optimal mixing ratio of solidifying and adjusting agents, and (3) conducting mineralogical and morphological analyses of products from the hydration reactions of manufactured non-sintered cement solidifier (NSCS) containing waste concrete generated from nuclear-decommissioning facilities. The analytical results of NSCS using waste soil and clay minerals confirmed none of the hydration products, but calcium silicate (CSH) and ettringite were examined as hydration products in the case of using BFS. The compressive strength of NSCS manufactured with the optimum mixing ratio and using waste soil and clay minerals was 3 MPa after the 28-day curing period, and it was not satisfied with the acceptance criteria (3.44 MPa) for being brought in disposal sites. However, the compressive strength of NSCS using BFS was estimated to be satisfied with the acceptance criteria, despite manufacturing conditions, and it was maximized to 27 MPa at the optimal mixing ratio. The results indicate that the most relevant NSCS for the safe containment of radioactive waste can be manufactured using BFS as solidifying agent and using waste soil and clay minerals as adsorbents for radioactive nuclides.

• Analytical Science and Technology
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• v.10 no.4
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• pp.300-306
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• 1997

The effective resolution of the direct current potential drop (DCPD) method for crack length determination is strongly affected by a number of factors including wire locations and calibration method. In the present study, the effects of wire locations, thermal EMF and reference probe locations on the accuracy of calibration methods, including Hicks-Pickard equation and Johnson's equation, were examined with the CT specimens which were nine times larger than the standard specimen. In light of experimental results, it was found that Hicks-Pickard equation can accurately represent the a/W-V/Vo relationship when current input wire is located at the load line. It was also found that the accuracy of DCPD method can be greatly improved with the thermal EMF calibration and the use of Vo value at a/W = 0.241. The use of reference potential was found to be impractical when current input wire is located at the load line.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.92-99
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• 2017

In Korea, the zero energy building was designated as the 7 new industries in the Ministry of Land and the 8 new industries in the Ministry of Industry. In order to maximize the insulation performance of the building envelope, improve the efficiency of building equipment, We are aiming. It is necessary to analyze the energy requirements of the buildings (cooling, heating, hot water supply, lighting, ventilation) of buildings with energy efficiency level of 1++ which is equivalent to the zero energy building certification system in Korea, It is aimed to be used as basic data for the advancement of energy building certification system. Zero Energy Building certification is estimated to be 61 buildings by 2017, and the approximate reference value and the first energy requirement for each of the five loads are calculated considering passive and active aspects. It is difficult to say that it is a clear standard because there is a small sample of data for calculating the load standard. However, it is necessary to interpret various methods in order to upgrade the Zero Energy Building certification standard in the future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.4
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• pp.271-280
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• 2013

Since the decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete waste have been generated. In Korea, the decontamination and decommissioning of the KRR-1, 2 at the KAERI have been under way. And concrete waste was generated about 800 drums of 200 L. The conditioning of concrete waste is needed for final disposal. The concrete waste is conditioned as follows: mortar using coarse and fine aggregates is filled void space after concrete rubble pre-placement into 200 L drum. Thus, this research has developed an optimizing mixing ratio of concrete waste, water, and cement and has evaluated characteristics of a cement waste form to meet the requirements specified in disposal site specific waste acceptance criteria. The results obtained from compressive strength test, leaching test, thermal cycling test of cement waste forms conclude that the concrete waste, water, and cement have been suggested to have 75:15:10wt% as the optimized mixing ratio. Also, the compressive strength of cement waste form was satisfied that including fine powder up to maximum 40wt% in concrete debris wastes about 75%. As a result of scale-up test, the mixture of concrete waste, water, and cement is 75:10:15wt% meet the satisfied compressive strength because the free water increased with and increased in particle size.