• 한국융합학회논문지
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• 제9권11호
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• pp.291-297
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• 2018

의료 현장에서의 최소침습수술(MIS)의 어려움 때문에 시뮬레이터 훈련이 활발히 연구되고 있다. 이를 위해 본 연구에서는 S-chain모델을 사용하여 가상 장기와 변형과정을 표현하고 반발력 제공이 가능한 햅틱 시뮬레이터를 개발하고자 한다. S-chain알고리즘의 주요 원리는 반발력이 체인 요소의 수에 비례하는 것이며, 대상인 장기의 변형이 클수록 많은 계산시간을 요구한다. 이에 본 연구에서는 계산속도가 개선된 S-chain알고리즘을 회전움직임에 적용하여 제어성능을 평가하였다. 본 연구에서는 자기 점성 점성(MR) 유체를 사용하는 햅틱 마스터 시스템을 제안하고 S-chain모델을 개발한다. 결과적으로, 이 S-chain모델을 사용하여 가상의 장기와 실제 마스터 장치를 결합함으로써 반발력과 수술로봇의 좌표 위치를 서로 전달하는 햅틱 시스템을 구축하여, 햅틱 시뮬레이터의 제어 성능을 실험을 통해 평가하였다.

• Journal of Information Technology Applications and Management
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• 제22권2호
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• pp.201-217
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• 2015

In this paper, we report computational testing result to examine the validity of firm's bankruptcy risk estimation through quantification of supply chain risk. Supply chain risk in this study refers to upstream supply risk and downstream demand risk, To assess the firm's risk affected by supply chain risk, we adopt unit of analysis as industry level. since supply and demand relationships of the firm could be generalized by the industry input-output table and the availability of various valid economic indicators which are chronologically calculated. The research model to estimate firm's risk level is the linear regression model to assess the industry bankruptcy risk estimation of the focal firm's industry with the independent variables which could quantitatively reflect demand and supply risk of the industry. The publicly announced macro economic indicators are selected as the candidate independent variables and validated through empirical testing. To validate our approach, in this paper, we confined our research scope to steel industry sector and its related industry sectors, and implemented the research model. The empirical testing results provide useful insights to further refine the research model as the valid forecasting mechanism to capture firm's future risk estimation more accurately by adopting supply chain industry risk aspect, in conjunction with firm's financial and other managerial factors.

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.99-106
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• 2017

With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.259-262
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• 2004

In most of the character recognition systems, the method of template matching or statistical method using hidden Markov model is used to extract and recognize feature shapes. In this paper, we used modified chain-code which has 8-directions but 4-codes, and made the chain-code of hand-written character, after that, converted it into transition chain-code by applying to HMM(Hidden Markov Model). The transition chain code by HMM is analyzed as signal flow graph by Mason's theory which is generally used to calculate forward gain at automatic control system. If the specific forward gain and feedback gain is properly set, the forward gain of transition chain-code using Mason's theory can be distinguished depending on each object for recognition. This data of the gain is reorganized as tree structure, hence making it possible to distinguish different hand-written characters. With this method, $91\%$ recognition rate was acquired.

• 산업경영시스템학회지
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• 제31권4호
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• pp.10-20
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• 2008

This paper deals with the application of Supply Chain Operations Reference (SCOR) model to make a Service Supply Chain(sSC) of a hospital treatment service. At first, we compare the service supply chain with the traditional supply chain. At second, we apply the SCOR model to a service supply chain of a hospital treatment service and make new process of the hospital service supply chain if we need it. Finally, we explain the applied results and propose the improvement points. The used level of SCOR model is from level 1 to level 3.

• 한국시스템다이내믹스연구
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• 제8권1호
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• pp.173-186
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• 2007

This research consists of (1) building (or molding) the Dynamics Simulation Model on Return Policy mainly used in publications, phonographs, and computer industry; which are seen used in supply chain contract known as effective control mechanism under the varied supply chain situations, and (2) analyzing the effects that return rates and seller's contract parameters have in the outcome of the model and (3) observing how the effectiveness of Return Policy changes under such circumstances where the buyer's sales ability and the seller's risk inclination are taken into account. Thus, the main purpose of this research lies in analyzing what exactly are the effects (and or outcome) that sales ability and risk inclination have in Return Policy, and additionally by conducting comprehensive research on Supply Chain Policy Dynamics Simulation Model, we will try to prove that not only the Systems Dynamics approach is highly contributive in supply chain management but also that it will serve as a foothold in future research. As a result of the research, supply chain achievement level turned out to be high when Return Policy is enforced, and the achievement level was even higher when seller's sales ability was taken into consideration along with the Return Policy. On the other hand, the achievement level decreased when the seller had risk aversive tendencies.

• 한국시스템다이내믹스연구
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• 제12권4호
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• pp.157-175
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• 2011

The purpose of this paper is to find out the effects of the gambler's fallacy bias on the supply chain. For this study, the simulation was based on a casual structure of the Beer Distribution Game from Sterman(2000)'s Business Dynamics and designed into 2 different models : the first model carries the exact same structure as the reference mentioned above and for the second model, the comparison model is used reflecting gambler's fallacy bias. Each model has 2 different demand patterns. The 4 cases of models was tested with 1,000 different random number seeds. The results for the simulation are following : In the aspect of the inventory and out of stock, the basic model resulted better than the comparison. However, in the bullwhip effect, the comparison model has less than the basic in terms of the level demand pattern. But there was no significant difference in the cycle demand.

• 수산경영론집
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• 제40권2호
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• pp.27-48
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• 2009

The objective of this paper is to estimate consumer's marginal willingness to pay(MWTP) for cold chain system attributes of mackerel using choice experiment questionnaires. The survey data were analyzed by conjoint analysis method with multinominal logit model. The five cold chain system attributes with $2{\sim}4$ attribute levels were considered : low temperature safekeeping of fishing boats, a kind of transport truck and packing box, using degree of low temperature facility in distribution, mackerel price per fish(1kg). At least 827 people were asked to participate in the survey. The major findings and implications of this study can be summarized as follows : The estimated multinominal logit model is statistically significant and the total consumers willingness to pay for the improved cold chain system attributes is 6,476 won (per kg). Compared with the base price(2,500 won/kg), the estimated MWTP is 2.5 times higher than the base price. Therefore, the consumer has a willingness to pay for the fresh and safe fish products, even though more money is paid. To satisfy the consumer's needs, cold chain system is necessary in point of long-term. In this reason, The government's policy support is needed for promoting cold chain system in fishery, and a master plan should be prepared.

• 산업경영시스템학회지
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• 제36권4호
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• pp.25-30
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• 2013

This article deals with the transient analysis in bicycle shifting using a discrete chain model. Among the various components of a bicycle, we focused in the power-transmissions on the contact points between the chain element and sprocket. And by imposing kinematic motions on the front and rear derailleurs, we analyzed the shifting mechanism for increasing the rotational speed of rear wheel. In order to build the dynamic analysis model, we first tore down the real bicycle and measured each component's design parameters. Then we made 3-dimensional CAD models for each component related to the power transmission of a bicycle. Using the converted 3-dimensional dynamic model for the simulation program, we performed non-shifting and shifting dynamic analysis. As a result, we investigated the dynamic behaviors of a discrete chain model focused on the interaction between the chain and sprocket wheel.

• Journal of Information Processing Systems
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• 제15권3호
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• pp.655-669
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• 2019

Supplier evaluation is of great significance in green supply chain management. Influenced by factors such as economic globalization, sustainable development, a holistic index framework is difficult to establish in green supply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertainty and incompleteness and the index weight is variable. To solve these problems, an index framework is established after comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is put forward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paper is feasible and effective.