• Title/Summary/Keyword: large solution

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Electrocatalytic Reduction of Dioxygen at Schiff base Co(II) Complexes supported Glassy Carbon Electrode in various pH Solution

  • Park, Kyoung-Hee;Rim, Chae-Pyeong;Chjo, Ki-Hyung;Jeon, Seungwon;Choi, Yong-Kook
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.617-622
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    • 1995
  • Electrocatalytic reduction of dioxygen has been investigated by cyclic voltammetry at glassy carbon electrode modified with new Co(II)-Schiff base complexes in aqueous solutions of various pH. The reduction potentials of dioxygen at chemically adsorbed electrodes show the dependence of pH between pH 4 and 14. The catalytic effect is large and the reaction occurs via two or four electron transfer in various pH solution.

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Efficient Elitist Genetic Algorithm for Resource-Constrained Project Scheduling

  • Kim, Jin-Lee
    • Korean Journal of Construction Engineering and Management
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    • v.8 no.6
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    • pp.235-245
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    • 2007
  • This research study presents the development and application of an Elitist Genetic Algorithm (Elitist GA) for solving the resource-constrained project scheduling problem, which is one of the most challenging problems in construction engineering. Main features of the developed algorithm are that the elitist roulette selection operator is developed to preserve the best individual solution for the next generation so as to obtain the improved solution, and that parallel schedule generation scheme is used to generate a feasible solution to the problem. The experimental results on standard problem sets indicate that the proposed algorithm not only produces reasonably good solutions to the problems over the heuristic method and other GA, but also can find the optimal and/or near optimal solutions for the large-sized problems with multiple resources within a reasonable amount of time that will be applicable to the construction industry. This paper will help researchers and/or practitioners in the construction project scheduling software area with alternative means to find the optimal schedules by utilizing the advantages of the Elitist GA.

Nickel Mesh for EMI Shielding by Continuous Electroforming (전주도금법에 의한 전자파 차폐용 Ni메쉬 제조기술)

  • Kim, Man;Gwon, Sik-Cheol;Park, Sang-Eon;Lee, Gyeong-Ryeol
    • 연구논문집
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    • s.33
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    • pp.183-190
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    • 2003
  • Today, We have used many electronic equipment such as computer, TV, cellular phone and so on. These equipment radiate a large amount of EMI(Electromagnetic interference) which is occurred trouble of airplane, medical equipment, communicate equipment, and especially, human health. So, Ni mesh fabrication for EMI shielding by continuous electroforming process was investigated. Continuous electroforming apparatus was made by means of rotating cathode drum. And We investigated the characteristics of two types of Ni electroforming solution. One was made by laboratory and the other was produced by M cooperation. The grain size increased with increasing current density and bath temperature, and decreasing rotating speed of cathode drum. EDX results indicate that the Ni mesh electroformed by the KIMM solution is composed of pure Ni. But the Ni mesh electroformed by the M cooperation solution has Ni and S element. The incorporation of S element in the Ni mesh has a profoundly effect on mechanical properties such as hardness, internal stress and so on.

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Supply Chain Network Design - a Model and its Applications (공급사슬망 설계를 위한 수리모형 수립 및 응용)

  • Kim Jeonghyuk;Kim Daeki
    • Korean Management Science Review
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    • v.21 no.2
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    • pp.15-25
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    • 2004
  • Great effort has been exerted to redesign the supply chain network as a means to improve corporate competitiveness. In this study, we present a mathematical model and a solution system to help redesign corporate logistics networks. The objective of the model is to minimize total logistics costs. We applied the solution system to real problem cases. We use the model and the concept to develop decision support system that is based on C++ with the use of CPLEX callable library as a solution engine. We tested and verified the DSS for redesigning the network of a large Korean electronics company. Through various scenario analyses. we recommend to redesign their supply chain network that demonstrates the possibility of substantial logistics cost savings.

Exact Solution on the Anti-symmetric Responses of Ships having Uniform Sectional Properties with Hydro-elasticity (균일단면 선박의 유탄성 수평응답에 대한 해석해)

  • ;;A. Korobkin
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.4
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    • pp.45-52
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    • 2004
  • Exact solution on the anti-symmetric response of ships having uniform sectional properties in waves is derived. Boundary value problem consisted of Timoshenko beam equation and free-free end condition is solved analytically. The responses are assumed as linear and wave loads are calculated by using strip method. Horizontal bending moment, shear force and torsional moment are calculated. The developed analysis model is used for the benchmark test of the numerical codes in this problem. Also the application on the preliminary design of barge-like ships and VLFS (Very Large Floating Structure) is expected

Exact Solution on the Vertical Hydro-elastic Responses of Ships having Uniform Sectional Properties (균일단면 선박의 유탄성 수직응답에 대한 해석해)

  • Park, In-Kyu;Jung, Jong-Jin;A. Korobkin
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.2
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    • pp.47-54
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    • 2004
  • Exact solution on the vertical responses of ships having uniform sectional properties in waves is derived. Boundary value problem consisted of Timoshenko beam equation and free-free end condition is solved analytically. The responses are assumed as linear and wave loads are calculated by using strip method. Vertical bending moment, shear force and deflection are calculated. The developed analysis model is used for the benchmark test of the numerical codes in this problem. Also the application on the preliminary design of barge-like ships and VLFS (Very Large Floating Structure) is expected.

A Hybrid Hardware Architecture for LCD Overdrive Frame Buffer Reduction

  • Choi, Ji-Yong;Jeong, An-Sun;Baek, Jun-Geun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.814-817
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    • 2007
  • We present a hybrid hardware architecture capable of encoding and decoding a full HD resolution video with 60 fps. A number of technical modifications are applied to an existing image compression algorithm not only to accommodate large videos at a high frame rate but to enhance the quality of synthetic images, such as characters and video game images. Image quality of the proposed algorithm at a 1/6 compression ratio was comparable to that of the BTC based 1/3 compression algorithm.

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Improvement of Continuation Power Flow System Applying the Optimal Load Shedding Algorithm (최적 부하절체 알고리듬을 적용한 연속조류계산의 향상)

  • Song, Hwa-Chang;Lee, Byong-Jun;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.899-901
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    • 1998
  • Continuation power flow is a tool that can trace the path of the solution from the base stable solution. However, the base stable solution cannot be calculated when the initial system load is too large to operate at a stable operating point. This case is called as unsolvable case. This paper presents implementation of the optimal load shedding algorithm on continuation power flow. It performs steady-state analysis of power systems at unsolvable case that can occur in contingency analysis. Numerical simulation on 20-bus test system demonstrates that the continuation power flow applying the optimal load shedding algorithm is robust at solvable and unsolvable cases.

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Zn$_2SiO_4$ : Mn Phosphor Particles Prepared by Spray Pyrolysis Process

  • Kang, Yun-Chan;Park, Hee-Dong;Lim, Mi-Ae
    • Journal of Information Display
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    • v.2 no.4
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    • pp.57-62
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    • 2001
  • Green-emitting $Zn_2SiO_4$:Mn phosphor particles having a spherical shape and high luminescence intensities under VUV were prepared by spray pyrolysis process under severe preparation conditions. The type of precursor solutions affected the morphology and luminescence characteristics of the prepared particles. The particles prepared from the clear solution by laboratory-scale process had spherical shape and dense morphology, while the particles prepared from the severe preparation conditions had rough surface and collapsed structure. However, the particles prepared from the colloidal solution utilizing fumed silica were spherical in shape and filled morphology at the severe preparation conditions of high flow rate of carrier gas, high concentration of solution, and large reactor size. The prepared $Zn_2SiO_4$:Mn phosphor particles with complete spherical shape had higher photoluminescence intensity than that of the commercial product prepared by solid state reaction.

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Electrochemical Characteristics of Aqueous Polymeric Gel Electrolyte for Supercapacitor (수퍼커패시터용 수용성 고분자 젤 전해질의 전기화학적 특성)

  • ;Masashi ISHIKAWA;Masayuki MORITA
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.93-96
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    • 2001
  • We have reported to make nanostructured cobalt oxide electrode that have large capacitance over than 400F/g (specific capacitance) and good cycleability. But, It had serious demerits of low voltage range under 0.5V and low power density. Therefore, we need to increase voltage range of cobalt oxide electrode. we report here on the electrochemical properties of sol-gel-derived nanoparticulate cobalt xerogel in 1M KOH solution and aqueous polymeric gel electrolyte. In solution electrolyte, cobalt oxide electrode had over than 250F/g capacitance consisted of EDLC and pseudocapacitance. In gel electrolyte, cobalt oxide electrode had around 100F/g capacitance. This capacitance was only surface EDLC. In solution electrolyte, potassium ion as working ion reacted with both of layers easily. However, In gel electrolyte, reacted with only surface-active layer. Its very hard to reach resistive layer. So, e have studied on pretretmetn of electrode to contain working ions easily. We'll report more details.

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