• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2194-2205
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• 1995

In order to reduce the systematic error of a build-up system, we have proposed a new test procedure in which all force transducers in a build-up system are rotated by 90.deg. with a base platen fixed on a force standard machine. The setting positions of force transducers on the output of a build-up system were investigated using an orthogonal array. The effects of the parallelism of a build-up system and of the bending moment sensitivity of a force transducer were considered. The experimental results show that the setting position of the base platen hardly affects the output of the build-up system, but the setting positions of force transducers affects it strongly. It reveals that the new test procedure reduces effectively the systematic error of a build-up system.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.25-27
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• 2006

This paper proposes a new full ZVS-range asymmetrical half bridge converter. It uses the variable transient current build-up technique with the load variations. The current build-up is accomplished by using the secondary synchronous switch control. Due to the blocking capacitor in secondary side, the voltage applied to leakage inductor varies with the load variations during current build-up period. Therefore, the unnecessary current build-up of leakage inductor current in heavy load condition is prevented and more current build-up in medium and light load condition is achieved for ZVS operation. That is, the variant current build-up with the load variation is accomplished for the ZVS operation. Furthermore, the DC offset of the transformer magnetizing current is also eliminated and the utilization of magnetic core is maximized.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.477-484
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• 1997

This paper describes the build-up force measuring system of 9.9 MN capacity which consists of nine force transducers of each having 1.1 MN capacity. We have specially designed a force transducer for a build-up force measuring system to reduce the uncertainty of a build-up system and to accomodate the new test procedure for a build-up system. It reveals that the relative uncertainty of the force measuring system is less than 1.5*10$^{-4}$ in the ran9e of 1-4.5 MN irrespective of loading direction. The force measuring system may be used to calibrate a 10 MN force standard machine to be used as a large force standard in Korea.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.674-680
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• 2022

In the present study, radiation shielding and protection ability of prepared Flyash-lime-Gypsum (FaLG) bricks has been studied in terms of energy exposure build up factors and dose parameters. The energy exposure build up factors of Flyash-lime-Gypsum (FaLG) bricks have been calculated for the energy range of 0.015 MeV-15 MeV and for penetration depth upto 40 mfp directly using a new and simplified Piecewise Linear Spline Interpolation Method (PLSIM). In this new method, the calculations of G.P fitting parameters are not required. The verification and accuracy of this new method has been checked by comparing the results of exposure build up factor for NBS concrete calculated using present method with the results obtained by using G.P fitting method. Further, the relative dose distribution and reduced exposure dose rate for various radioactive isotopes without any shielding material and with Flyash-lime-Gypsum (FaLG) bricks have been calculated in the energy range of 59.59-1332 keV. On the basis of the obtained results, it has been reported that the prepared Flyash-lime-Gypsum (FaLG) bricks possess satisfactory radiation shielding properties and can be used as environmentally safe storage facilities for low level nuclear waste.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.10a
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• pp.355-361
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• 1999

An application of case-based reasoning is proposed to build an influence diagram for identifying successful new ventures. The decision to invest in new ventures in characterized by incomplete information and uncertainty, where some measures of firm performance are quantitative, while some others are substituted by qualitative indicators. Influence diagrams are used as a model for representing investment decision problems based on incomplete and uncertain information from a variety of sources. The building of influence diagrams needs much time and efforts and the resulting model such as a decision model is applicable to only one specific problem. However, some prior knowledge from the experience to build decision model can be utilized to resolve other similar decision problems. The basic idea of case-based reasoning is that humans reuse the problem solving experience to solve a new decision. In this paper, we suggest a case-based reasoning approach to build an influence diagram for the class of investment decision problems. This is composed of a retrieval procedure and an adaptation procedure. The retrieval procedure use two suggested measures, the fitting ratio and the garbage ratio. An adaptation procedure is based on a decision-analytic knowledge and decision participants knowledge. Each step of procedure is explained step by step, and it is applied to the investment decision problem in new ventures.

• Journal of Information Processing Systems
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• v.8 no.1
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• pp.175-190
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• 2012

Shuffling is an effective method to build a publicly verifiable mix network to implement verifiable anonymous channels that can be used for important cryptographic applications like electronic voting and electronic cash. One shuffling scheme by Groth is claimed to be secure and efficient. However, its soundness has not been formally proven. An attack against the soundness of this shuffling scheme is presented in this paper. Such an attack compromises the soundness of the mix network based on it. Two new shuffling protocols are designed on the basis of Groth's shuffling and batch verification techniques. The first new protocol is not completely sound, but is formally analyzed in regards to soundness, so it can be applied to build a mix network with formally proven soundness. The second new protocol is completely sound, so is more convenient to apply. Formal analysis in this paper guarantees that both new shuffling protocols can be employed to build mix networks with formally provable soundness. Both protocols prevent the attack against soundness in Groth's scheme. Both new shuffling protocols are very efficient as batch-verification-based efficiency-improving mechanisms have been adopted. The second protocol is even simpler and more elegant than the first one as it is based on a novel batch cryptographic technique.

• Korean Journal of Computational Design and Engineering
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• v.11 no.3
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• pp.223-233
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• 2006

Layered manufacturing(LM) is emerging as a new technology that enables the fabrication of three dimensional heterogeneous objects such as Multi-materials and Functionally Gradient Materials (FGMs). Among various types of heterogeneous objects, more attention has recently paid on the fabrication of FGMs because of their potentials in engineering applications. The necessary steps for LM fabrication of FGMs include representation and process planning of material information inside an FGM. This paper introduces a new process planning algorithm that takes into account the processing of material information. The detailed tasks are discretization (i.e., decomposition-based approximation of volume fraction), orientation (build direction selection), and adaptive slicing of heterogeneous objects. In particular, this paper focuses on the discretization process that converts all of the material information inside an FGM into material features like geometric features. It is thus possible to choose an optimal build direction among various pre-selected ones by approximately estimating build time. This is because total build time depends on the complexity of features. This discretization process also allows adaptive slicing of heterogeneous objects to minimize surface finish and material composition error. In addition, tool path planning can be simplified into fill pattern generation. Specific examples are shown to illustrate the overall procedure.

• Korean Management Science Review
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• v.26 no.1
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• pp.113-126
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• 2009

By the newly emerging network access technology, we face the new heterogeneous network environment. Focusing on the co-existence of multiple access network technology and the complex service needs of users, the wireless service operators should present the stable service quality for every user. For this, the service operators should build the new operation framework which combine the pre-established network and newly adopted one. Our problem is finding the optimal heterogeneous network operation framework. We suggest market-based marginal cost function for evaluating the relative value of resource of each network and develop the whole new heterogeneous network operation framework. To test the applicability of developed operation framework, we build large-scale JAVA simulator. By this development, we can easily test the new network environment in practical engineering field.

• Journal of the Korean Professional Engineers Association
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• v.42 no.2
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• pp.54-60
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• 2009

On January of this year, the 29th National Science and Technology Council, presided by President M.B. Lee, officially finalized a contract for a big project to build an International Science and Business Belt(ISBB) that includes the establishment of a new institute, the Asian Basic Science Institute (ABSI) and the construction of a Rare Isotope Accelerator. The government will inject more than 3.5 trillion Wan into the ISBB project. The investment to build the care laboratory for the project, the heavy ion accelerator, the first one in Korea, will be 460 billion Wan, Korea thus aiming to build an accelerator with world-class performance. This will be the sixth in the world. The construction will start from 2012, and is planned to finish by 2015. ABSI, whose construction will be finished by 2012, is planned to be a care laboratory with 3,000 scientists and staff. To. attract world class researchers and other professionals from aver the world, the project includes the creation of a new city with a superb educational, cultural environment, and comfortable living environment for an international community. The site for this new science and business city, "scientific ecosystem", has not been officially decided yet, and supposed to be announced in the first half af this year.

• Strategy21
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• s.40
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• pp.162-189
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• 2016

This research deals with the PLAN's capabilities and its implication for regional security, and suggests some measures for maritime security cooperation among regional states. China has began to focus its national strategy more on 'rising as a new maritime power' since the 18th Party Convention in November 2012. Chinese new strategy aims at building a strong navy, contributing economic prosperity and national security, and thus elevating its prestige in international society. Most of all, building a strong navy is the foremost task at this time, and that is why the PLAN has the priority for military modernization. Chinese new maritime strategy could cause naval arms race in East Asia and aggravate maritime territorial disputes among concerned parties. It is the time for regional states to discuss some measures to build confidence, such as arms control of naval weapons, establishment of multilateral maritime security mechanism, and foundation of regional security regime, thus enhancing regional maritime cooperation.