• Title/Summary/Keyword: missing data recovery

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Study on the Optimal Design of Automatic Data Recovery System in case of Communication Loss in Remote Management of Hydraulic Facilities (수리시설물 원격관리에 있어 통신두절시 데이터 자동복구 시스템 최적설계에 관한 연구)

  • Ahn, Tae-Hyung;Kim, Sang-Yu;Ko, Jeong-Min;Kim, Jae-Yeol
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.4
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    • pp.46-52
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    • 2022
  • In the existing wired communication network, wired communication is frequently interrupted by lightning, which accompanies rain, and remote management cannot be performed when it is actually necessary. In the case of communication interruption, field data stored in the database are lost, and data at an important point in time may go missing; this causes a decrease in the reliability of the stored data. Therefore, in this study, wireless communication using the Internet of Things (IoT) communication network of the 4th industrial technology is installed in the prototype to reduce wired communication construction costs, prevent resource waste and environmental damage due to communication facility construction, and prepare for communication loss.

The Role of Justice, Authenticity, and Advice in Retailer's Service Recovery (유통점의 서비스회복 노력이 회복만족에 미치는 영향: 공정성, 진정성, 조언수용을 중심으로)

  • Shin, Yong-Sun;Kim, Moon-Seop
    • Journal of Distribution Science
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    • v.16 no.12
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    • pp.105-113
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    • 2018
  • Purpose - This research is intended to suggest ways to enhance customers' satisfaction with service recovery. For this purpose, this study investigated the relationships among perceived justice (distributive, procedural, interactional justice) of service recovery efforts, perceived authenticity of service recovery efforts, the intention to follow advice, and the satisfaction with service recovery. Research design, data, and methodology - This research developed a structural equation model in which the perceived justice (distributive, procedural, interactional justice) and the perceived authenticity are predictors, the satisfaction with service recovery is a dependent variable, and the intention to follow advice is a moderator between the perceived justice (distributive, procedural, interactional justice) and the satisfaction with service recovery. Data were collected from visitors of fast food restaurants in Seoul, Gyeonggi province, and Kangwon province. A total of 330 questionnaires were distributed and 295 responses were collected indicating a response rate of 89.3%. After deleting data having missing value, 288 samples were used for analysis. SPSS 21.0 and AMOS 21.0 were used to test the reliability, validity, model fit, and hypotheses. Results - Empirical results showed that perceived justice, perceived distributive justice, and perceived authenticity had a positive influence on the satisfaction with service recovery. These results indicated that the more highly customers perceived the justice, distributive justice and the authenticity of service recovery efforts, the more they were satisfied with service recovery. And these influences were moderated by the intention to follow advice. Specifically, influences of the perceived justice, the perceived distributive justice, and the perceived authenticity on the satisfaction with service recovery were bigger for people with high intention to follow advice than people with low intention to follow advice. Conclusions - This research contributed to the service recovery literature by showing how perceived justice (distributive, procedural, interactional justice) and perceived authenticity influence satisfaction with service recovery. Moreover, current study introduced the intention to follow advice as moderator of this influence and revealed the moderation role of the intention to follow advice between the perceived justice (distributive, procedural, interactional justice) and the satisfaction with service recovery. Managerially, these results suggested retailing companies some ways to recover from service failure.

An Error Recovery Mechanism for Communications with Reliability in Sensor Network (센서 네트워크에서 신뢰성 있는 통신을 위한 에러 복구 기법)

  • Min, Byung-Ung;Kim, Dong-Il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.360-363
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    • 2007
  • In sensor network, the importance of transporting data with reliability is growing gradually to support communications. Data flow from sink to nodes needs reliability for the control or management, that is very sensitive and intolerable, however relatively, data flow from nodes to sink is tolerable. In this paper, with emphasis of the data flow from sink to nodes, we proposed the mechanism that establishes confidence interval for transport. Establishing confidence interval hop-by-hop, not end to end, if errors happen or there's missing data, this mechanism recovers them with selective acknowledgement using fixed window. In addition, this mechanism supports traffic congestion control depending on the buffer condition. Through the simulation, we showed that this mechanism has an excellent performance for error recovery in sensor network.

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An Error Recovery Mechanism for Communications with Reliability and Transport Control for Media Access in Sensor Network (센서 네트워크에서의 매체제어를 위한 전송제어 및 신뢰성 있는 통신을 위한 에러 복구 기법)

  • Min, Byung-Ung;Kim, Dong-Il;Choi, Sam-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1190-1194
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    • 2007
  • In sensor network, the importance of transporting data with reliability is growing gradually to support communications. Data flow from sink to nodes needs reliability for the control or management, that is very sensitive and intolerable, however relatively, data flow from nodes to sink is tolerable. In this paper, with emphasis of the data flow from sink to nodes, we proposed the mechanism that establishes confidence interval for transport. Establishing confidence interval herby-hop, not end to end, if errors happen or there's missing data, this mechanism recovers them with selective acknowledgement using fixed window. In addition, this mechanism supports franc congestion control depending on the buffer condition. Through the simulation, we showed that this mechanism has an excellent performance for error recovery in sensor network.

A Study on the Management Improvement of Disaster Recovery Resources of Municipality with Field Survey (현장실태조사를 활용한 지자체 재난관리자원 관리 개선 연구)

  • Kim, Joon-Ha;Kim, Tae-Heon;Jung, Jae-Wook
    • Journal of the Society of Disaster Information
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    • v.16 no.1
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    • pp.155-162
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    • 2020
  • Purpose: The purpose of study was to identify problems in disaster recovery resource management and operation through on-site investigation and utilize them as improvement proposal for disaster recovery resources management by local governments. Method: Areas with high natural and social disasters recorded in historical and yearly records of natural and social disasters, related books, and annual reports for 20 years were selected. The DRSS data of the selected local governments were analyzed and the reserve warehouse were selected for field survey. Result: It is analyzed that the current situation in the city hall and district offices is somewhat insufficient due to heavy work by the working-level officials of local governments on the storage of disaster recovery resources. The actual amount of stockpiles and DRSS data are somewhat different or missing because the input method and criteria are not clear at present when inputting the current data. Conclusion: To improve the management of the disaster recovery resource reserve, it is deemed that education of DRSS and training of best practices for the operation of disaster management resources are urgently needed, and that a systematic management of stockpiles using disaster prevention experts will be required.

Data Processing and Visualization Method for Retrospective Data Analysis and Research Using Patient Vital Signs (환자의 활력 징후를 이용한 후향적 데이터의 분석과 연구를 위한 데이터 가공 및 시각화 방법)

  • Kim, Su Min;Yoon, Ji Young
    • Journal of Biomedical Engineering Research
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    • v.42 no.4
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    • pp.175-185
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    • 2021
  • Purpose: Vital sign are used to help assess the general physical health of a person, give clues to possible diseases, and show progress toward recovery. Researchers are using vital sign data and AI(artificial intelligence) to manage a variety of diseases and predict mortality. In order to analyze vital sign data using AI, it is important to select and extract vital sign data suitable for research purposes. Methods: We developed a method to visualize vital sign and early warning scores by processing retrospective vital sign data collected from EMR(electronic medical records) and patient monitoring devices. The vital sign data used for development were obtained using the open EMR big data MIMIC-III and the wearable patient monitoring device(CareTaker). Data processing and visualization were developed using Python. We used the development results with machine learning to process the prediction of mortality in ICU patients. Results: We calculated NEWS(National Early Warning Score) to understand the patient's condition. Vital sign data with different measurement times and frequencies were sampled at equal time intervals, and missing data were interpolated to reconstruct data. The normal and abnormal states of vital sign were visualized as color-coded graphs. Mortality prediction result with processed data and machine learning was AUC of 0.892. Conclusion: This visualization method will help researchers to easily understand a patient's vital sign status over time and extract the necessary data.

A Study on the ISAR Image Reconstruction Algorithm Using Compressive Sensing Theory under Incomplete RCS Data (데이터 손실이 있는 RCS 데이터에서 압축 센싱 이론을 적용한 ISAR 영상 복원 알고리즘 연구)

  • Bae, Ji-Hoon;Kang, Byung-Soo;Kim, Kyung-Tae;Yang, Eun-Jung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.9
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    • pp.952-958
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    • 2014
  • In this paper, we propose a parametric sparse recovery algorithm(SRA) applied to a radar signal model, based on the compressive sensing(CS), for the ISAR(Inverse Synthetic Aperture Radar) image reconstruction from an incomplete radar-cross-section(RCS) data and for the estimation of rotation rate of a target. As the SRA, the iteratively-reweighted-least-square(IRLS) is combined with the radar signal model including chirp components with unknown chirp rate in the cross-range direction. In addition, the particle swarm optimization(PSO) technique is considered for searching correct parameters related to the rotation rate. Therefore, the parametric SRA based on the IRLS can reconstruct ISAR image and estimate the rotation rate of a target efficiently, although there exists missing data in observed RCS data samples. The performance of the proposed method in terms of image entropy is also compared with that of the traditional interpolation methods for the incomplete RCS data.

A mediating role of social capital between corporate social responsibility and corporate reputation: Perception of local university on CSR of KHNP

  • JOO, Jae-Hun
    • The Journal of Industrial Distribution & Business
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    • v.11 no.3
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    • pp.63-71
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    • 2020
  • Purpose: Most of all studies regarding corporate social responsibility have been dealing with its direct performance. Many previous studies provided the evidence that corporate social responsibility activities directly affect firms' competitiveness or corporate reputation. However, there are no studies regarding the role of social capital between corporate social responsibility and firms' competitiveness. The present study aims to examine a mediating role of social capital between corporate social responsibility and corporate reputation. Research design, data and methodology: The structural equation model integrating corporate social responsibility, social capital, and corporate reputation was proposed with three hypotheses. Questionnaire including 15 question items for three concepts was designed. Data for testing hypotheses were collected from students and staff who had experienced the social responsibility activities of Korea Hydro & Nuclear Co. Ltd. SPSS and SmartPLS were used to analyze data. Results: All three hypotheses were supported at the significance level of 0.01. Corporate social responsibility have a significant influence on social capital as well as corporate reputation. Social capital plays a mediating role in the relationship between corporate social responsibility and corporate reputation. Conclusions: The present paper identified a missing link between corporate social responsibility and corporate reputation by validating an indirect effect of corporate social responsibility on corporate reputation through social capital. The present study contributes to finding the indirect link between corporate social responsibility and corporate reputation. Implications for academics and practitioners. The research model can be extended to analyze the relationship between corporate social responsibility and its performance. The present study sheds light on identification of a new role of social capital. Managers of firms have the opportunity to recognize the fact that investment recovery of corporate social responsibility results from social capital and corporate reputation in long-term rather than short-term. The results of this study offers an insight that managers can enhance customer loyalty. The process linking corporate social responsibility to corporate reputation through social capital implies that firms can realize spiritual marketing delivering authentic storytelling through corporate social responsibility. The present study has a limitation for generalizing of research results because the sampling came from a case of firm.

A Design of DLL-based Low-Power CDR for 2nd-Generation AiPi+ Application (2세대 AiPi+ 용 DLL 기반 저전력 클록-데이터 복원 회로의 설계)

  • Park, Joon-Sung;Park, Hyung-Gu;Kim, Seong-Geun;Pu, Young-Gun;Lee, Kang-Yoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.4
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    • pp.39-50
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    • 2011
  • In this paper, we presents a CDR circuit for $2^{nd}$-generation AiPi+, one of the Intra-panel Interface. The speed of the proposed clock and data recovery is increased to 1.25 Gbps compared with that of AiPi+. The DLL-based CDR architecture is used to generate the multi-phase clocks. We propose the simple scheme for frequency detector (FD) to mitigate the harmonic-locking and reduce the complexity. In addition, the duty cycle corrector that limits the maximum pulse width is used to avoid the problem of missing clock edges due to the mismatch between rising and falling time of VCDL's delay cells. The proposed CDR is implemented in 0.18 um technology with the supply voltage of 1.8 V. The active die area is $660\;{\mu}m\;{\times}\;250\;{\mu}m$, and supply voltage is 1.8 V. Peak-to-Peak jitter is less than 15 ps and the power consumption of the CDR except input buffer, equalizer, and de-serializer is 5.94 mW.

Korea Coast Guard's Human Biological Materials Storage Project for Identifying Bodies Recovered from the Sea: A Model Suggestion (해양변사자 신원확인을 위한 해양경찰의 인체유래물 보관사업 모델제시)

  • Joo, Hyunjung;Choo, Minkyu;Baek, Yoongi;Kim, Namyul;Choi, A-jin;Im, Sonyoung;Lee, Jongnam;Kim, Hyungkyu;Lee, Hanseong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.2
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    • pp.171-178
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    • 2018
  • The ocean is a harsh environment and Korea Coast Guard officers often face the threat of death or going missing in the line of duty. In order to promptly identify unknown bodies during mishaps, Korea Coast Guard Research Center has established an identification system using the DNA of its officers. This collected DNA can also be entombed in National Cemeteries when the remains are not recovered. The storage, disposal and quality control of the materials are overseen by the Governing Committee according to the Enforcement Rules for the Human Biological Materials Storage Project for the Identification of Officers Killed or Gone Missing in Action. Approximately 700 bodies are found per year along the Korean coast. An alternative method should be put in place for when identification through fingerprints and teeth are not applicable due to severe decomposition or partial recovery. We believe it would greatly contribute to helping identify the unknown bodies if the storage project could expand its data to include marine industry workers, relevant researchers and those involved in marine leisure activities.