• 제어로봇시스템학회논문지
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• 제10권12호
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• pp.1148-1154
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• 2004

The goal of this paper is to verity that the gradual reduction of drug dose (GRDD), which has already been shown by authors to be effective for a simplified HIV infection model, still works for a more realistic model. While the simplified HIV infection model does not take into account an helper-independent CTL, the five state nonlinear model proposed by Wodarz describes the dynamics of both helper-dependent and helper-independent CTL in HIV infection. In this paper, it is shown that, by applying GRDD to Wodarz's five state HIV infection model, the state of HIV infected patient converges to that of non-progressor whose immune response is excited so that his symptom would not be developed into AIDS. Roughly speaking, GRDD is 'slow reduction of dose after the maximum dose for a certain period.' It turns out that an equilibrium representing non-progressor is locally asymptotically stable for the most values of drug dosage, which is required to hold in order to apply GRDD. Simulation results establish that GRDD is still considerably effective both for an AIDS patient and a patient who has been on HAART for a long time.

• 한국자동차공학회논문집
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• 제2권2호
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• pp.24-32
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• 1994

This paper is the experimental study on the vibration reduction of the 4WD vehicle through the change of the engine mounting conditions.(4 stroke diesel engine) The engine mounting conditions are changed to reduce the transmitted vibrations of the engine to the frame at the idle speed. Under the assumption that the Powertrain(Engine Transmission and Transfer Case) is a rigid body, the inertia properties of the powertrain are obtained by experimental modal analysis. And then the changed mounting conditions are studied by the decoupled vibration theory and analytical model of six degree of freedom. Though the mounting conditions are changed to improve the vibration isolation at idle speed, the vibration and the interior noise of the vehicle are reduced significantly at driving speed as well as idle speed. From the indirect endurance test of the front engine mounts, the changed mounting conditions are desirable to endurance as well as vibration reduction of the 4WD vehicle.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.849-858
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• 2015

This study set the pyroprocess facility at an engineering scale as a cost object, and presented the cost consumed during the unit processes of the pyroprocess. For the cost calculation, the activity based costing (ABC) method was used instead of the engineering cost estimation method, which calculates the cost based on the conceptual design of the pyroprocess facility. The calculation results demonstrate that the pyroprocess facility's unit process cost is $194/kgHM for pretreatment, $298/kgHM for electrochemical reduction, $226/kgHM for electrorefining, and $299/kgHM for electrowinning. An analysis demonstrated that the share of each unit process cost among the total pyroprocess cost is as follows: 19% for pretreatment, 29% for electrochemical reduction, 22% for electrorefining, and 30% for electrowinning. The total unit cost of the pyroprocess was calculated at $1,017/kgHM. In the end, electrochemical reduction and the electrowinning process took up most of the cost, and the individual costs for these two processes was found to be similar. This is because significant raw material cost is required for the electrochemical reduction process, which uses platinum as an anode electrode. In addition, significant raw material costs are required, such as for $Li_3PO_4$, which is used a lot during the salt purification process.

• 산업경영시스템학회지
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• 제18권35호
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• pp.131-138
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• 1995

For the purpose of the reduction of tile cost, a production/inventory model including the interference phenomenon was developed. By investigating the cause and the characteristics of the direct/indirect cost due to the interference phenomenon, a strategy for suitable production was developed. The developed model was quantitatively validated using an existing-EPQ model and the SIMAN package was used to simulate and animate the model. Consequently, it was presented that the total operating cost of the system could be decreased with tile proposed model.

• 분석과 대안
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• 제4권2호
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• pp.5-38
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• 2020

This paper investigates how public opinion has affected the United States Senate's votes on arms control treaties. Applying multilevel modeling with post-stratification to national polls, this paper produces estimates of state-level opinion on both the New Strategic Arms Reduction Treaty of 2010 and the Comprehensive Test Ban Treaty of 1999. Using these estimate, this paper examines the relationship between public opinion and the Senate's votes on the treaties. This paper finds that the influence of public opinion was mostly significant but indirect. These findings indicate that some version of the delegate model of representation is more applicable to foreign policy making in Congress.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1998년도 춘계 학술논문발표회 논문집
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• pp.265-270
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• 1998

As the goal of enterprises is to pursuit benefits, the goal of safety management is not only preventing accidents but also promoting benefits and productivity. However, enterprises have failed to realize the necessity of safety management, partly because they didn't grasp any appropriate evidences advocating effectiveness of safety management. This study aimed to survey construction-site engineers' consciousness on safety management contributing to cost reduction, construction period and quality enhancement. The result of this study showed that constriction-site engineers recognized the ratio of direct cost to Indirect cost as 1:2. The proportion of repliers who thought that safety management is contributable to cost reduction was 35％, to construction period was 20％, and to quality enhancement was 48％. The construction sites with excellent safety accomplisments also had good work and selling amounts.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.821-824
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• 2009

LFG-MGT CHP system development project with $CO_2$ enrichment in greenhouses was introduced. LFG is produced from the anaerobic digestion of landfilled waste and it has been utilized for power/heat generation since it contains around 50% of $CH_4$. Utilization of LFG from small scale landfill is also needed as well as large scale landfill. However, due to economy of scale, it is very difficult to develop business model. In this context, combining CHP system with greenhouses is considered as feasible option for LFG utilization. LFG-MGT CHP system with $CO_2$ fixation in greenhouses has been derived as an active greenhouse gas reduction strategy, The focus of the system is beyond carbon neutral LFG utilization to neutral carbon absorption. The system is feasible in terms of direct and indirect $CO_2$ emission reduction with more economical way.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.790-795
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• 2002

The object of this research is limited to the reduction of compression process noise only among the main sources of compressor noise such as motor noise, compression process noise, and valve port flow noise. Thus the research is focused on the wave motion rather than the particle motion of sound wave travels. A muffler is a commonly used device to reduce the compression process noise, generated by the pressure pulsations caused by the cyclic compression process. In this research, the acoustic characteristics of the muffler are analyzed by using the normal gradient integral equation proposed by Wu and Wan. Moreover, a commercial code SYSNOISE developed by indirect variational boundary integral equation is also used to validate the results. For the noise reduction, the topology optimization technique using a genetic algorithm is used. The number, size and position of the muffler holes are considered as design variables. Compared with original design, the optimized design has very improved acoustic characteristics. Both numerical and experimental analyses are used to evaluate new design.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1371-1373
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• 2008

Recently, the reduction of greenhouse gas (GHG) is the most important international issue. In order to control efficiently GHG emissions and reduction, it is essential to establish GHG inventory preferentially. The aim of this study was to establish the GHG inventory of Korean railroad. The GHG sources were divided into direct and indirect emissions. The GHG released from the operation of rolling stocks was classified according to operating line and the kind of car. Finally, the GHG emission of Korean railroad can be managed systematically using this GHG inventory.

• 방사선산업학회지
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• 제8권2호
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• pp.71-76
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• 2014

Endocrine disrupting chemicals (EDCs) and potential EDCs are mostly man-made, found in various materials such as pesticides, additives or contaminants in food, and personal care products. The high energy ionizing radiation has the ability to remove the EDCs with a very high degree of reliability and in a clean and efficient manner. The ionizing radiation interacts with EDCs both directly and indirectly. Direct interaction takes place with EDCs and the structure of EDCs is destroyed or changed. During indirect interaction, radiolysis products of water result in the formation of highly reactive intermediates which then react with the target molecules, culminating in structural changes. To confirm the radiation reduction of EDCs in industrial sludge, a pilot scale experiment up to 50 kGy of electron beam (EB) was conducted with samples from the textile dyeing industries. The experimental result showed the over 90% of reduction of Nonylphenol (NP) and Di(2-ethylhexyl) phthalate (DEHP) at around 10 kGy of absorbed doses.