• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.359-367
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• 2018

Long-lived Small Modular Reactors are being promoted as an innovative way of catering to emerging markets and isolated regions. They can be operated continuously for decades without requiring additional fuel. A novel configuration of long-lived reactor core employs a mixed neutron spectrum, providing an improvement in nonproliferation metrics and in safety characteristics. Starting with a base sodium reactor design, moderating material is inserted in outer core assemblies to modify the fast spectrum. The assemblies are shuffled once during core lifetime to ensure that every fuel rod is exposed to the thermalized spectrum. The Mixed Spectrum Reactor is able to maintain a core lifetime over two decades while ensuring the plutonium it breeds is below the weapon-grade limit at the fuel discharge. The main drawbacks of the design are higher front-end fuel cycle costs and a 58% increase in core volume, although it is alleviated to some extent by a 48% higher power output.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.276-284
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• 2000

In this paper, the genetic algorithm is used to design a mixed H₂/ H/sub ∞/ controller Two kinds of controller forms, Youla's form and the general form, are considered to design a mixed H₂/ H/sub ∞/ controller. Efficient searching methods are sought to minimize the given H₂cost function under the H∞ constraint. It is verified by an example that the developed algorithm can provide stable results in the region where unstable results are shown by the conventional gradient method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.979-984
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• 2003

Quality control of ready-mixed concrete is most important in the production step because, the performance of hardened concrete is revealed due to ready-mixed concrete. Hardened concrete has several properties physically. Above all things compressive strength of concrete has a greate effect in the design of structures, analysis, and durability. Compressive strength is simple predicted by w/c up to date, but there are some limits because different compressive strengths can be revealed in the same w/c. Therefore this study contributes to the quality control of ready-mixed concrete through statistical analysis for the relation between mix factors in mix design and compressive strength, predictable equation for compressive strength.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.331-331
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• 2000

This paper presents the mixed $H_2/H_{\infty}$ output feedback controIler design method for linear systems with delayed state. The objective is to design the output feedback controller which minimizes the H$_2$-norm of one transfer function while ensuring the H$_{\infty}$-norm of the other is held below a chosen level. When objective is tormulated in terms of a common Lyapunov function, the sufficient conditions of existence of mixed $H_2/H_{\infty}$ controller are given in terms of LMIs. terms of LMIs.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.285-289
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• 2008

There has been a project in Japan recently to develop the mixed-use facility in order to help regenerate its city's vitality. They must make efficient use of resources that contains historical and local identity. In contrast, Korea hasn't considered developing their mixed-use facilities for maintaining their historical identity. This research will analyze how locality is reflected in the 8 mixed-use facilities in Japan. The research method was as follows: Preparatory study and literature research were conducted to extract the elements of locality shown in the mixed-use facilities in Japan. According to the results, the peculiarities of locality are as follows: 1) It's important to make the most of the local Identity by reflecting on the historical peculiarity of the region. 2) Nature and its environmental surroundings should be considered when constructing buildings in order to revitalize its local identity. 3) In the perception aspect, when a mixed-use facility is open for visit, the negative elements such as the 'peripheral regional gap' that may be felt by the visitor must be kept to the minimum.

• Structural Engineering and Mechanics
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• v.3 no.4
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• pp.373-382
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• 1995

The weighting strategy has received a great attention and has been widely applied to multicriterion optimization. This gaper examines a global criterion method (GCM) with the weighting objectives strategy in fuzzy structural engineering problems. Fuzziness of those problems are in their design goals, constraints and variables. Most of the constraints are originated from analysis of engineering mechanics. The GCM is verified to be equivalent to fuzzy goal programming via a truss design. Continued and mixed discrete variable spaces are presented and examined using a fuzzy global criterion method (FGCM). In the design process a weighting parameter with fuzzy information is introduced into the design and decision making. We use a uniform machine-tool spindle as an illustrative example in continuous design space. Fuzzy multicriterion optimization in mixed design space is illustrated by the design of mechanical spring stacks. Results show that weighting strategy in FGCM can generate both the best compromise solution and a set of Pareto solutions in fuzzy environment. Weighting technique with fuzziness provides a more relaxed design domain, which increases the satisfying degree of a compromise solution or improves the final design.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.684-689
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• 2001

In this study, three-dimensional viscous flow analysis and optimization are presented for the design of a mixed-flow fan. Steady, imcompressible, three-dimensional Reynolds averaged Navier-Stokes equations are used as governing equations, and standard $k-{\varepsilon}$ turbulence model is chosen as a turbulence model. Governimg equations are discretized using finite volume method. Upwind difference scheme is used for the discretization of the convective term and SIMPLEC algorithm is used as a velocity-pressure correction procedure. The computational results are compared with the results obtained by TASCflow. For the numerical optimization of the design, objective function is defined as a ratio of generation of the turbulent energy to pressure head. Sweep angles are used as design variables.

• IE interfaces
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• v.15 no.2
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• pp.189-198
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• 2002

Simulated Annealing(SA) approach has been successfully applied to the combinatorial optimization problems with NP-hard complexity. To apply an SA algorithm to specific problems, generic parameters as well as problem-specific parameters must be determined. To overcome the embedded nature of SA, long computational time, some studies suggested the parameter design methods of determining SA related parameters. In this study, we propose a new parameter design approach based on robust design method. To show the effectiveness of the proposed method, the extensive computation experiments are conducted on the mixed-model sequencing problems.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.118-123
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• 2004

In this study, genetic algorithm mixed binary and real encoding is proposed to deal with design variables of various types. And that is applied to optimum design of Multi-stage gear drive. Design of pressure vessel which is mixed discrete and continuous variables is applied to verify reasonableness of proposed genetic algorithm. The proposed genetic algorithm is applied for the gear ratio optimization and the volume minimization of geared motor which is used in field. In result, it shows that the volume has decreased about 8% compared with the existing geared motor.

• Korean Institute of Interior Design Journal
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• v.23 no.4
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• pp.211-219
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• 2014

The internal streets of mixed-use commercial complexes, which are the extension of urban streets, are being changed from a mediating space aiming at movement to a staying-type space according to the change of mixed-use commercial complexes. And they function as a resting place of user with court and plaza, and act as an urban public space, and accommodate an activity arising from the gathering of many people. As a result, a role of new relaxation and community space is played in the center of the city. And the aspect of publicness is brought into relief. Hence, this study is intended to examine the characteristics that the internal streets of mixed-use commercial complexes have, and furthermore, it is intended to show the planning characteristics in the contemporary mixed-use commercial complexes. With regard to the method of research, first, space configuration and role of internal streets was examined according to the change of mixed-use commercial complexes on the basic of precedent research and literature review. And the internal streets of mixed-use commercial complexes were classified into doorway part, traffic line, and open space. And the characteristics of internal streets in the mixed-use commercial complexes through the concept of architectural 'publicness' were derived as accessibility, amenity, perceptibility, openness, connectivity and symbolism. The internal streets of mixed-use commercial complexes should be changed by the space planning to secure continuity with the city on the basis of accessibility and connectivity and to reinforce visual openness in the internal streets in order to improve amenity and perceptibility, accordingly the mixed-use commercial complexes will be also born again as symbolic public space in the city. Variously changing elements to improve publicness very importantly act on the planning of internal streets in the mixed-use commercial complexes, and therefore researches should be continuously carried out.