• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2010년도 정기 학술대회
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• pp.268-271
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• 2010

In this paper, forward and reverse analysis is introduced in order to estimate the elastic-plastic properties from a power-law hardening bulk specimen materials with one simple spherical indentation impression test. In order to verify the reliability of the reverse analysis, we have simulated about a large range of materials that essentially cover all engineering materials, using ABAQUS(6.91) program. Then, we could obtained the fitting functions and plastic parameters from the numerical analysis results. Next, through the procedure of reverse analysis we can obtain the yield stress and power-law exponent. Finally, obtain good agreement between the result from reverse analysis and initial input data from experiment.

• 산업경영시스템학회지
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• 제34권3호
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• pp.57-70
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• 2011

To address global climate change, various governments are investing in electric vehicle research and, especially in Korea, the application of electric vehicles to public transportation. The lithium batteries used in electric vehicles typically have an expected life cycle of 2-5 years. If electric vehicles become commonly used, they will generate many discarded batteries that could be harmful to the environment. Additionally, lithium batteries are potentially explosive and should be handled appropriately. Thus, reverse logistics issues are involved in handling expired batteries efficiently and safely. Reverse logistics includes the collection, recycling, remanufacturing, and discarding of waste. This study developed a reverse logistics process for electric vehicle batteries after analyzing the as-is process for lead and lithium batteries. It also developed possible disposal regulations for electric vehicle batteries based on current laws regarding conventional batteries.

• 한국정밀공학회지
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• 제20권10호
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• pp.191-198
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• 2003

In this study, aberration free aspherical lens design method named ray reverse tracing method is introduced. Differently from the traditional design method, the ray reverse tracing method traces the shape and location of a real object by use of its virtual image. From the result, especially spherical aberration free aspherical lens could be designed by use of the ray reverse tracing method. Furthermore, it could reduce the degree of dependence of optical characteristics on designer's ability, because deformation terms and optimization can be eliminated, which has been performed in conventional lens design process.

• Industrial Engineering and Management Systems
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• 제9권4호
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• pp.303-311
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• 2010

In the last few years growing interest has been dedicated to supply chain management. Modeling complexity is added to supply chain coordination problem by accounting for reverse logistics activities. The objective of this paper is to extend inventory model of manufacturing factory with respect to the production of raw material of forward logistics and recycling material of reverse logistics. The proposed model is applied to a plastic recycling process plant located in Taiwan. The case study improvement scheme shows when the recycling rate of recycling material increases from 15% to 50%, the total inventory cost of manufacturing factory decreases by 12.82%, safety stock volume decreases by 41.19% and the reorder quantity is down by 50.96%. This paper finds whether the results of the model can reach the economic profit through quantitative analysis and encourages companies integrate reverse logistics into the supply chain system.

• 한국통신학회논문지
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• 제22권3호
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• pp.571-579
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• 1997

There are some transmission types on the reverse link of wideband DS-CDMA cellular system. The configurations of logical channels on the reverse link may be different dependent upon the transmission methods of reverse pilot or control signaling. In this paper, we present three transmission types on the wideband DS-CDMA reverse link; no-pilot system, pilot-channel aided system and pilot-symbol aided system. And we compare the performance of three systems in terms of capacity and cell coverage. The pilot-symbol aided system is shown to have the better performance than the pilot-channel aided system in both capacity and cell coverage.

• Journal of Power Electronics
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• 제16권1호
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• pp.57-65
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• 2016

Reverse matrix converters, which can step up voltages, are suitable for applications with source voltages that are lower than load voltages, such as generator systems. Reverse matrix converter topologies are advantageous because they do not require additional components to conventional matrix converters. In this paper, a detection method and a post-fault modulation strategy to operate a converter as close as possible to its desired normal operation under the open-switch fault condition in the rectifier stage are proposed. An open-switch fault in the rectifier stage of a reverse matrix converter causes current distortions and voltage ripples in the system. Therefore, fault-tolerant control for open-switch faults is required to improve the reliability of a system. The proposed strategy determines the appropriate switching stages from among the remaining healthy switches of the converter. This is done based on reference currents or voltages. The performance of the proposed strategy is experimentally verified.

• 한국인쇄학회지
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• 제30권2호
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• pp.23-33
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• 2012

With the development of many display technologies currently applied to them in the field of printed electronics, there have been many researches that high resolution printing for thin and uniform pattern. In this paper, printing ink flow properties in the reverse offset mechanism were simulated. The aim of this research is to expect the ink flow behavior between cliches to make fine pattern by a printing technique which is a reverse offset. The simulation results show that almost the same as the experiments and the flow behavior according to the ink film thickness and printing pressure changes could be expected.

• Clinics in Shoulder and Elbow
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• 제20권3호
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• pp.172-179
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• 2017

Indications of reverse total shoulder arthroplasty (RTSA) have been consistently extended by technical advancements in reverse arthroplasty prosthesis, continuous development of the implants, accumulated experiences and its successful treatment outcomes; accordingly, its use has rapidly increased. RTSA has been performed for a variety of indications, with variable outcomes depending on the initial diagnosis. However, controversial opinions still exist regarding the design of reverse arthroplasty prosthesis (medialized or lateralized design and the neck-shaft angle of the humeral prosthesis), suture of the subscapularis tendon, use of cement during placement of the humeral prosthesis, and surgical procedures; therefore, these should be investigated so that they can be better understood.

• Water Engineering Research
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• 제4권1호
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• pp.1-17
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• 2003

A mathematical model was developed to simulate the performance of a prototype wind-powered reverse osmosis desalination system. The model consists of two sub-models operated in a series. The first sub-model is the wind-energy conversion sub-model, which has wind energy and feed water as its input and pressurized feed water as its output. The second sub-model is a reverse osmosis (RO) process sub-model, with pressurized feed water as its input and the flow and salinity of the product water or permeate as its output. Model coefficients were determined based on field experiments of a prototype wind powered RO desalination system of the University of Hawaii, from June to December 2001. The mathematical model developed by this study predicts the performance of wind-powered RO desalination systems under different design conditions. The system optimization is achieved using a linear programming approach. Based on the results of system optimization, a design guide is prepared, which can be used by both manufacturer and end-user of the wind-driven reverse osmosis system.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.36-41
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• 2006

Reverse flow (i.e. flow in the direction opposite to the free stream) inside a channel occurs when an obstruction is placed at certain positions near the near to the channel, placed in another wider channel. In this paper the reverse flow in a duct (diameter D) with an obstruction at the front (which is a disc), is investigated using PIV. The gap g between the obstruction and the entry to the duct is systematically varied and it is found that maximum reverse flow occurs at a g/D value of 0.5. The flow is stagnant around g/D of 1.25 and forward flow occurs for g/D values of 1.5 and above.