• Journal of Forest and Environmental Science
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• 제32권1호
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• pp.55-67
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• 2016

This paper investigated policies that drive the sustainable management of Ivorian forest which disappear at an annual rate of 250000 hectares. Based on an inter-temporal model for optimum allocation of forest land to three competing uses, the article found that sustainability depends on the incentive structure, of which forest taxes and fees are a key, though obviously not the sole, component. The study proposed to increase the area fee level by accounting for environmental externalities generated by forest harvesters and farmers. The paper showed that the area fee is a decreasing function of the forest natural rate of regeneration and the reconversion rate of agricultural surfaces. Finally, at the given forest natural rate of regeneration and the reconversion rate of agricultural surfaces, the model argued that the area fee need to be progressive (arithmetic progression) in the context of ecological equilibrium break while it should remain constant in normal situation.

• Journal of Positioning, Navigation, and Timing
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• 제9권2호
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• pp.139-147
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• 2020

In this paper, design measure were proposed for the construction of terminal systems for airborne platforms, which are key element in the Joint Tactical Data Link System (JTDLS) complete system. The Korean perfect tactical data link (JTDLS) is a communication system to establish an independent tactical data link network and needs to develop a MIDS-LVT (Link-16) communication terminal for datalink. Once a Ground/Navy JTDLS terminal system is established around airborne platform, it will be possible to break away from reliance on NATO-based tactical data link joint operations and establish independent Korean surveillance reconnaissance real-time data sharing and tactical data link operations concepts. in this paper, the essential development elements of airborne platform mounting and operable JTDLS terminals are presented, and the concept of system design is proposed to embody them. Further, improved system performance was analyzed by applying the concepts of complex relative navigation system and Advanced TDMA protocol for the deployment of airborne tactical datalink networks.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1049-1054
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• 2002

Fluid Pulsation in pipe usually cause several forces and these forces make mechanical vibration and noise. Protecting pipe from mechanical vibration is very important problem because vibration make pipe damage and break. To analyze pipe, we must formulate both the fluid pulsation force and vibration of pipe. In this paper fluid force from pulsation is modeled by Fluid Dynamics and solved by FEM(finite element method). The discharge pipe is also modeled by the FEM with use of 6 dof beam model. The acceleration of discharge pipe is estimated by the suggested method in this paper. The comparision of estimated results with experimental results show good agreement, which verified the validation of this method

• International Journal of Internet, Broadcasting and Communication
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• 제10권3호
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• pp.104-108
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• 2018

Lithium-ion batteries have been used in energy storage systems (ESS), electric vehicles (EVs), etc. due to their high safety, fast charging and long lifecycle. This paper aims to improve the convenience of users by changing the wired battery stack used in the battery pack, wirelessly using RFID, reducing the internal volume of the battery pack, reducing the size of the battery pack. In this paper, we propose a battery management system which can provide the flexibility of battery pack expansion and maintenance by using lithium ion battery, battery management system (BMS) and wireless communication for light weight of 1Kw small battery pack. Also, by flexibly arranging the cell layout inside the battery pack and designing to reduce the size of the outer shape of the battery pack.

• 대한산업공학회지
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• 제14권2호
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• pp.53-61
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• 1988

Games such as baseball, soccer are scheduled by a given game type such as tournament, league or their mixed form. The objective of this paper is to find an efficient game-scheduling method with respect to traveling distance, break-time and other conditions. In this paper we first present two models which minimize traveling distance. The first model that a match is played once each other is solved by a heuristic method. In the second model that a match is played more than once, teams are paired by a modified 0 - 1 programming, and the pairs are rearranged in order to generate a number of workable schedules. Then Expert Systems is applied to solve breake-time and other conditions. In order to represent expertise's knowledge effectively, we present a new design of knowledge-base and data-base, inference engine including many rules and meta-rules which controls the global system. In knowledge-base, binary relation among various attributes is used to ease not only knowledge acquisition but also system execution.

• Industrial Engineering and Management Systems
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• 제11권1호
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• pp.11-17
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• 2012

Along with the recent trend toward increasing variety and shorter life of products in the market, evaluation of risk for economic investment alternatives is of practical importance in manufacturing companies. This paper assumes that each alternative is composed of demand volume and unit sales price as income factors, and unit variable cost and fixed cost as expense factors. The paper assumes that these four factors move worse from the originally expected values, toward the direction of decreasing profit. Values of these four factors are also assumed to fluctuate from year to year over the entire multi-period. By applying the analysis of the breakeven points to each of the four factors, safer area against these changes is represented on the two dimensional domain called normalized total-cost unit-cost domain. A practical numerical example is analyzed to verify the validity of the proposed method.

• 전기학회논문지
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• 제56권8호
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• pp.1390-1396
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• 2007

The line-start permanent magnet synchronous motor has a high efficiency and an advantage in constant speed operation regardless of the effect of load variation. However, it is difficult to predict the performance of characteristics accurately, because of the unbalanced starting torque with the initial starting position of the rotor and the generation of a break torque. In this paper the dynamic characteristics of the line-start permanent magnet synchronous motor are described and compared with those of the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bars in the line-start permanent magnet synchronous motor. Finally this paper gives the comparison between the simulation results and the experimental results.

• 펄프종이기술
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• 제41권3호
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• pp.71-75
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• 2009

Cotton waste is usually used for cultivating agaric mushroom after outdoor fermentation for a few months. Electron beam was used to break down the polymer chaims of cotton waste for increasing low molecular weight soluble sugars, which may enhance the agaric mushroom cultivation. By increasing electron beam radiation, alpha cellulose content of the cotton waste was decreased while beta cellulose content and hot water solubles were increased. Electron beam radiation over 240 kGy on cotton waste caused significant increase of mushroom yield without lowering mushroom quality.

• 한국국방경영분석학회지
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• 제28권2호
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• pp.34-55
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• 2002

This paper deals with the multiple attribute decision making problem when a decision maker incompletely articulates his/her preferences about the attribute weight and alternative value. Furthermore, we consider the attribute tree which is structured hierarchically. Techniques for establishing dominance with linear partial information are proposed in a hierarchically structured attribute tree. The linear additive value function under certainty is used in the model. The incompletely specified information constructs a feasible region of linear constraints and therefore the pairwise dominance relationship between alternatives leads to intractable non-linear programming. Hence, we propose solution techniques to handle this difficulty. Also, to handle the tree structure, we break down the attribute tree into sub-trees. Due to there cursive structure of the solution technique, the optimization results from sub-trees can be utilized in computing the value interval on the topmost attribute. The value intervals computed by the proposed solution techniques can be used to establishing the pairwise dominance relation between alternatives. In this paper, pairwise dominance relation will be represented as strict dominance and weak dominance, which ware already defined in earlier researches.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.297-313
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• 2012

This paper is intended to show the robustness and capabilities of a coupled boundary element-finite element technique for the analysis of vibrations generated by high-speed trains under different geometrical, mechanical and operation conditions. The approach has been developed by the authors and some results have already been presented. Nevertheless, a more comprehensive study is presented in this paper to show the relevance and robustness of the method which is able to predict vibrations due to train passage at the vehicle, the track, the free-field and any structure close to the track. Local soil discontinuities, underground constructions such as underpasses, and coupling with nearby structures that break the uniformity of the geometry along the track line can be represented by the model. Non-linear behaviour of the structures can be also considered. Results concerning the excitation mechanisms, track behaviour and sub-Rayleigh and super-Rayleigh train speed are summarized in this work.