• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.56-63
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• 2006

Key recovery has been the subject of a lot of discussion, of much controversy and of extensive research. Key recovery, however, might be needed at a corporate level, as a form of key management. The basic observation of the present paper is that cryptographic solutions that have been proposed so far completely ignore the communication context. IPSec is a security protocol suite that provides encryption and authentication services for IP messages at the network layer of the Internet. We propose example to provide key recovery capability by adding key recovery information to an IP datagram. It is possible to take advantage of the communication environment in order to design key recovery protocols that are better suited and more efficient.

• Journal of Information Processing Systems
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• v.15 no.1
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• pp.55-66
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• 2019

Storage system often applies erasure codes to protect against disk failure and ensure system reliability and availability. Liberation code that is a type of coding scheme has been widely used in many storage systems because its encoding and modifying operations are efficient. However, it cannot effectively achieve fast recovery from single disk failure in storage systems, and has great influence on recovery performance as well as response time of client requests. To solve this problem, in this paper, we present HRSF, a Hybrid Recovery method for solving Single disk Failure. We present the optimal algorithm to accelerate failure recovery process. Theoretical analysis proves that our scheme consumes approximately 25% less amount of data read than the conventional method. In the evaluation, we perform extensive experiments by setting different number of disks and chunk sizes. The results show that HRSF outperforms conventional method in terms of the amount of data read and failure recovery time.

• Journal of Distribution Research
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• v.17 no.1
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• pp.1-36
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• 2012

Service failure is one of the major reasons for customer defection. As the business environment gets tougher and more competitive, a single service failure might bring about fatal consequences to a service provider or a firm. Sometimes a failure won't end up with an unsatisfied customer's simple complaining but with a wide-spread animosity against the service provider or the firm, leading to a threat to the firm's survival itself in the society. Therefore, we are in need of comprehensive understandings of complainants' attitudes and behaviors toward service failures and firm's recovery efforts. Even though a failure itself couldn't be fixed completely, marketers should repair the mind and heart of unsatisfied customers, which can be regarded as an successful recovery strategy in the end. As the outcome of recovery efforts exerted by service providers or firms, recovery of the relationship between customer and service provider need to put on the top in the recovery goal list. With these motivations, the study investigates how service failure and recovery makes the changes in dynamics of fundamental elements of customer-firm relationship, such as customer affection, customer trust and loyalty intention by comparing two time points, before the service failure and after the recovery, focusing on the effects of recovery satisfaction and the failure severity. We adopted La & Choi (2012)'s framework for development of the research model that was based on the previous research stream like Yim et al. (2008) and Thomson et al. (2005). The pivotal background theories of the model are mainly from relationship marketing and social relationships of social psychology. For example, Love, Emotional attachment, Intimacy, and Equity theories regarding human relationships were reviewed. As the results, when recovery satisfaction is high, customer affection and customer trust that were established before the service failure are carried over to the future after the recovery. However, when recovery satisfaction is low, customer-firm relationship that had already established in the past are not carried over but broken up. Regardless of the degree of recovery satisfaction, once a failure occurs loyalty intention is not carried over to the future and the impact of customer trust on loyalty intention becomes stronger. Such changes imply that customers become more prudent and more risk-aversive than the time prior to service failure. The impact of severity of failure on customer affection and customer trust matters only when recovery satisfaction is low. When recovery satisfaction is high, customer affection and customer trust become severity-proof. Interestingly, regardless of the degree of recovery satisfaction, failure severity has a significant negative influence on loyalty intention. Loyalty intention is the most fragile target when a service failure occurs no matter how severe the failure criticality is. Consequently, the ultimate goal of service recovery should be the restoration of customer-firm relationship and recovery of customer trust should be the primary objective to accomplish for a successful recovery performance. Especially when failure severity is high, service recovery should be perceived highly satisfied by the complainants because failure severity matters more when recovery satisfaction is low. Marketers can implement recovery strategies to enhance emotional appeals as well as fair treatments since the both impacts of affection and trust on loyalty intention are significant. In the case of high severity of failure, recovery efforts should be exerted to overreach customer expectation, designed to directly repair customer trust and elaborately designed in the focus of customer-firm communications during the interactional recovery process to affect customer trust rebuilding indirectly. Because it is a longer and harder way to rebuild customer-firm relationship for high severity cases, low recovery satisfaction cannot guarantee customer retention. To prevent customer defection due to service failure of high severity, unexpected rewards as a recovery will be likely to be useful since those will lead to customer delight or customer gratitude toward the service firm. Based on the results of analyses, theoretical and managerial implications are presented. Limitations and future research ideas are also discussed.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.179-182
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• 1998

Carrier recovery, the process of recoverying the carrier in receiver, removes the phase difference between VCO and the received signal. However, the conventional structure of carrier recovery cannot be applied to multi-level QAM demodulator because of the increasing decision interval and the complexity of control as the number of symbol increases. In this paper, we suggest a new carrier recovery algorithm using $\theta-matching$ algorithm for multi-level QAM demodulation to overcome this problem and analysis the performance and implement it.

• Journal of Korean Society for Quality Management
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• v.35 no.4
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• pp.111-122
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• 2007

The purpose of the study is to find out the influences of various efforts on service recovery after the failure of the service for the customer satisfaction and a loyalty. The present study finds out the factors directly affecting service recovery and demonstrates the relationship of those factors with customer satisfaction and loyalty. As a result, the important factors for service recovery are an immediate compensation, truthfulness, reaction and assurance

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.485-486
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• 2018

In this paper, we consider a binary recovery framework of the Compressed Sensing (CS) problem. We derive an upper bound for $L_0$ recovery performance of a binary sparse signal in terms of the dimension N and sparsity K of signals, the number of measurements M. We show that the upper bound obtained from this work goes to the limit bound when the sensing matrix sufficiently become dense. In addition, for perfect recovery performance, if the signals are very sparse, the sensing matrices required for $L_0$ recovery are little more dense.

• Journal of the Korean institute of surface engineering
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• v.14 no.4
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• pp.209-214
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• 1981

Electrolytic recovery of gold and silver from diluted solutions has at first been applied nearly 100 years ago. Compared with other recovery techniques electrolytic treatment offers several advantages. But to achieve high space-time yields special constructions of electrolytic cells for improved mass transfer are necessary. Ex-tended cathode surface areas and vigorous agitation are important features. Gold and silver recovery by use of newly developed electrolytic cell constructions - rotating tubular bed reactor and impact rod reactor - has been described. Calculations based on industrial application during several years are confirming that electrolytic recovery of precious metalss from diluted solutions has been operated in a very economic way.

• Review of KIISC
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• v.7 no.4
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• pp.45-58
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• 1997

본고에서는 현재 여러 국가와 기업에서 논의되고 있는 Key Recovery시스템이 제안된 배경과 미국에서의 시행 정책과 현황 등을 살펴보고 Key Recovery시스템을 구성하는 주요 요소와 실제 시스템의 구현시에 고려되어야 할 부분들을 보다 일반적인 관점에서 논의하고자 한다.

• Journal of Distribution Science
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• v.13 no.2
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• pp.63-73
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• 2015

Purpose - Satisfaction with service is evaluated according to customers' subjective judgment. The expected value of customer service and its evaluations depend on the customers' position. The customer recognizes two different forms of service levels. One is satisfaction and the other is dissatisfaction. Customers who are satisfied want to receive the service in future. However, those dissatisfied try to change the service. The service provider tries to improve the service. There are two different service cycles. One is the successful cycle and the other is the failure cycle. This study aimed to empirically determine the effects of the justice and authenticity of service recovery on customer behavioral intention through an integrated approach to cognitive justice and psychological authenticity. Research design, data, and methodology - Based on a literature review, justice of service recovery was categorized into three types: distributive, procedural, and interactive. Then, authenticity was added to obtain four independent variables, along with recovery satisfaction as a parameter. Behavioral intention, as an outcome variable, was divided into the repurchase intention and positive word-of-mouth. The model and hypotheses were created and measurement items were developed. A questionnaire survey of items concerning the service recovery experience at family restaurants was conducted on college students and residents in Gwangju from September 30 to October 31, 2013. A total of 400 copies of the questionnaire were sent out and 385 were returned. Respondents answered questions about the importance of, and satisfaction with service recovery on a 5-point Likert scale. Excluding 174 copies without service failure experiences and 7 inappropriate copies, 204 copies were analyzed using SPSS 21.0 for Windows and AMOS 20.0 to determine the reliability and validity of measurements. The hypotheses were tested through a goodness-of-fit analysis. Results - First, distributive justice positively affected recovery satisfaction. Second, procedural and interactive justice had no impact. Third, authenticity positively affected recovery satisfaction. Fourth, distributive justice had relatively stronger effects on recovery satisfaction than authenticity. Fifth, recovery satisfaction significantly affected repurchase intention and positive word-of-mouth and it proved effective in mediation. Finally, additional analysis was performed for descriptive statistics of the principal variables by various demographic characteristics and significant differences were found in gender, occupation, and so on. Conclusions - This study has academic significance as the fairness and authenticity of service recovery were investigated to reveal the effects on behavior. The findings could be applied to a wide range of service recovery strategies. However, there are some limitations. First, data was collected only from the residents of Gwangju and most respondents were aged 20-30. Future studies should target a wide range of areas and age groups. Second, because the questionnaire used in this study targets only convenience family restaurants, the results of this study cannot be generalized to all services companies. Future research should be done on a wide range of industries such as hotels, airlines, and hospitals, and perform a comparison between sectors.

• Korean Journal of Social Welfare
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• v.60 no.4
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• pp.175-203
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• 2008

It has been well known and empirically supported that many persons with psychiatric disabilities experience recovery in the community. The sense of recovery is experienced while they recognize and manage mental illness and cope with everyday life utilizing personal and social resources. In order to explore ways in which the sense of recovery is enhanced, this study investigated the structure of relationships among the mental health state, optimism, positive emotions, quantity and quality of the social relationships, coping, and recovery of 460 persons with psychiatric disabilities through structural equation modeling. Of findings, first, in the results of path estimates of measurement and theoretical model, especially optimism and positive emotions demonstrated significant effects on the social relationship, coping, and the recovery, while, by contraries, positive emotions showed no significant direct effects on coping, neither the social relationships did on the recovery. Second, on the recovery optimism and positive emotions had direct effects, while quantity and quality of the social relationships had only indirect effects. It is particularly noted that positive emotions showed stronger effects on the recovery than optimism, and also had direct and indirect effects on the social relationships. Finally, partial mediating effects of coping were found between optimism and the recovery, between quality of the social relationships and recovery, and between quantity and quality of the social relationships; another partial mediating effects of quality of social relationships between quantity of social relationships and coping, and between positive emotions and coping; and the last same effects of quantity of the social relationships between positive emotions and coping. According to these results, discussions and implications for social work practice and practice research were suggested regarding the differential effects of positive cognitions and emotions on the recovery and different mechanisms of the quality and quantity of the social relationships, and the relationships among the resources, coping, and the recovery of persons with psychiatric disabilities.