• Title/Summary/Keyword: Recovery Techniques

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The method of recovery for deleted record in Oracle Database (Oracle 데이터베이스의 삭제된 레코드 복구 기법)

  • Choi, Jong-Hyun;Jeong, Doo Won;Lee, Sangjin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.5
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    • pp.947-955
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    • 2013
  • Most of the enterprise information is stored in the database. Therefore, in order to investigate the company's criminal behavior, forensic analysis is important for the database and delete record is a need to develop recovery techniques. This paper is explained structure of the oracle database tablespace file and analyzed system tables that stored table information. Further, we suggests a method of recovery for deleted record in oracle tablespace.

A fault detection and recovery mechanism for the fault-tolerance of a Mini-MAP system (Mini-MAP 시스템의 결함 허용성을 위한 결함 감지 및 복구 기법)

  • Mun, Hong-Ju;Kwon, Wook-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.2
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    • pp.264-272
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    • 1998
  • This paper proposes a fault detection and recovery mechanism for a fault-tolerant Mini-MAP system, and provides detailed techniques for its implementation. This paper considers the fault-tolerant Mini-MAP system which has dual layer structure from the LLC sublayer down to the physical layer to cope with the faults of those layers. For a good fault detection, a redundant and hierarchical fault supervision architecture is proposed and its implementation technique for a stable detection operation is provided. Information for the fault location is provided from data reported with a fault detection and obtained by an additional network diagnosis. The faults are recovered by the stand-by sparing method applied for a dual network composed of two equivalent networks. A network switch mechanism is proposed to achieve a reliable and stable network function. A fault-tolerant Mini-MAP system is implemented by applying the proposed fault detection and recovery mechanism.

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File Signature's Automatic Calculation Algorithm Proposal for Digital Forensic

  • Jang, Eun-Jin;Shin, Seung-Jung
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.118-123
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    • 2021
  • Recently, digital crime is becoming more intelligent, and efficient digital forensic techniques are required to collect evidence for this. In the case of important files related to crime, a specific person may intentionally delete the file. In such a situation, data recovery is a very important procedure that can prove criminal charges. Although there are various methods to recover deleted files, we focuses on the recovery technique using HxD editor. When recovering a deleted file using the HxD editor, check the file structure and access the file data area through calculation. However, there is a possibility that errors such as arithmetic errors may occur when a file approach through calculation is used. Therefore, in this paper, we propose an algorithm that automatically calculates the header and footer of a file after checking the file signature in the root directory for efficient file recovery. If the algorithm proposed in this paper is used, it is expected that the error rate of arithmetic errors in the file recovery process can be reduced.

A Recovery Technique of PDF File in the Unit of Page (PDF 파일의 페이지단위 복구 기법)

  • Jang, Jeewon;Bang, Seung Gyu;Han, Jaehyeok;Lee, Sang Jin
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.1
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    • pp.25-30
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    • 2017
  • The influence of the data deletion method which is one of anti-forensic techniques is substantial in terms of forensic analysis compared to its simplicity of the act. In academic world, recovery techniques on deleted files have been continuously studied in response to the data deletion method and representatively, the file system-based file recovery technique and file format based recovery technique exist. If there's metadata of deleted file in file system, the file can be easily recovered by using it, but if there's no metadata, the file is recovered by using the signature-based carving technique or the file format based recovery technique has to be applied. At this time, in the file format based recovery technique, the file structure analysis and possible recovery technique should be provided. This paper proposes the page recovery technique on deleted PDF file based on the structural characteristics of PDF file. This technique uses the tag value of page object which constitutes one page of PDF file. Object is extracted by utilizing each tag value as a kind of signature and by analyzing extracted object, the metadata of PDF file is recombined and then it's reconfigured page by page. Recovering by page means that even if deleted PDF file is damaged, even some pages consisting of PDF file can be recovered. Generally, if the file system based file is not recoverable, deleted file is recovered by applying the signature based carving technique. The technique which we proposed in this paper can recover PDF files that are damaged. In the digital forensic perspective, it can be utilized to recover more data than previously.

Review on Self-embedding Fragile Watermarking for Image Authentication and Self-recovery

  • Wang, Chengyou;Zhang, Heng;Zhou, Xiao
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.510-522
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    • 2018
  • As the major source of information, digital images play an indispensable role in our lives. However, with the development of image processing techniques, people can optionally retouch or even forge an image by using image processing software. Therefore, the authenticity and integrity of digital images are facing severe challenge. To resolve this issue, the fragile watermarking schemes for image authentication have been proposed. According to different purposes, the fragile watermarking can be divided into two categories: fragile watermarking for tamper localization and fragile watermarking with recovery ability. The fragile watermarking for image tamper localization can only identify and locate the tampered regions, but it cannot further restore the modified regions. In some cases, image recovery for tampered regions is very essential. Generally, the fragile watermarking for image authentication and recovery includes three procedures: watermark generation and embedding, tamper localization, and image self-recovery. In this article, we make a review on self-embedding fragile watermarking methods. The basic model and the evaluation indexes of this watermarking scheme are presented in this paper. Some related works proposed in recent years and their advantages and disadvantages are described in detail to help the future research in this field. Based on the analysis, we give the future research prospects and suggestions in the end.

A Time-Redundant Recovery Scheme of TMR failures Using Retry and Rollback Techniques (재실행과 Rollback 기법을 사용한 TMR 고장의 시간여분 복구 기법)

  • Kang, Myung-Seok;Son, Byoung-Hee;Kim, Hag-Bae
    • The KIPS Transactions:PartA
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    • v.13A no.5 s.102
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    • pp.421-428
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    • 2006
  • This paper proposes an integrated recovery approach applying retry and rollback techniques to recover the TMR failure. Combining the time redundancy techniques with W system is apparently effective to recover the TMR failure(or masked error) primarily caused by transient faults. These policies need fewer reconfigurations at the cost of extra time required for the time redundant schemes. The optimal numbers of retry and rollback to minimize the mean execution time of tasks are derived for the proposed method through computing the likelihoods of all possible states of the failed system. The effectiveness of the proposed method is validated through examining certain numerical examples and simulations conducted with a variety of parameters governing environmental characteristics.

Analysis of Postural Stability and Daily Energy Expenditure to Manage Tumor Patients' Functional Expectation

  • Caliskan, Emrah;Saygi, Evrim Karadag;Gencer, Zeynep Kardelen;Kurtel, Hizir;Erol, Bulent
    • Clinics in Orthopedic Surgery
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    • v.10 no.4
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    • pp.491-499
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    • 2018
  • Background: Advances in surgical techniques, implant technology, radiotherapy, and chemotherapy have increased the recovery chances of patients with bone sarcomas. Accordingly, patients' expectations on life quality have also increased, highlighting the importance of objective evaluation of the functional results of reconstruction. Methods: Thirteen patients with distal femoral endoprosthesis, who had been followed for an average of 2.9 years were evaluated. Postural stability, daily energy expenditure, muscle power, and range of motion were the four parameters analyzed in this study. The Musculoskeletal Tumor Society (MSTS) score and Toronto Extremity Salvage Score (TESS) were used to assess postoperative function and examine correlations with other parameters. Results: Patients had sedentary activities in 84% of their daily lives. They exhibited a slower speed in the walk across test and a higher sway velocity in the sit-to-stand test (p = 0.005). MSTS scores were significantly correlated with the daily energy expenditure and walking speed. Conclusions: Objective functional results acquired from various clinics will provide significant data to compare reconstruction techniques, rehabilitation protocols, and surgical techniques. In this way, it will be possible to satisfy the expectations of patients that increase in relation to enhanced recovery.

Experiments on Non-Surgical Embryo Recovery and Transfer in Diry Cow. (젖소의 비수술적 수정란회수 및 이식시험)

  • Gu Ja-Hong;Cheong Chang-Kook
    • Journal of the korean veterinary medical association
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    • v.18 no.10
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    • pp.45-52
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    • 1982
  • Four experiments were conducted to improve non-surgical embryo recovery and transfer techniques in achieving acceptable success rate. In this experiments, 6 Holstein cows were submitted as embryo donors and of these, 5 donors were superovulated with pregn

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Management of Postoperative Complications Following Surgical Repair of Achilles Tendon Rupture (아킬레스건 파열의 수술 후 합병증의 치료)

  • Bae, Su-Young
    • Journal of Korean Foot and Ankle Society
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    • v.25 no.2
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    • pp.89-94
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    • 2021
  • The surgical repair of an Achilles tendon acute rupture is a proven, traditional treatment for optimal functional recovery. However, concerns regarding complications such as re-rupture, wound problems and infections are driving new techniques, including minimally invasive approaches and nonoperative treatments. If we understand the characteristics and contemplate treatment strategies for possible complications, the surgical repair of the Achilles tendon is an attractive option and can be expected to yield satisfactory functional recovery.

The Recovery Techniques on the Web Services-based e-Engineering Framework for Reliability Improvement (웹 서비스 기반 e-엔지니어링 프레임워크의 신뢰성 향상을 위한 회복 기법)

  • Kim, Dong-Uk;Kuk, Seung-Hak;Kim, Hyeon-Soo;Lee, Jai-Kyung
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.1
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    • pp.76-80
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    • 2008
  • In order to reduce a product life cycle and to improve productivity, it is required to automate the design/analysis processes. In general, since the design/analysis processes need a lot of time and resources, the various engineering resources should be integrated and utilized effectively in the distributed environments. KIMM (Korea Institute of Machinery and Materials) constructed the SOA-based e-Engineering framework to automate the execution of the design/analysis processes and to integrate the engineering resources in the distributed environments. This paper presents the concepts and the structures of the e-Engineering framework. Also it classifies the exceptional cases that will be able to occur in the e-Engineering framework and suggests the recovery techniques from the exceptional cases with viewpoints of the engineering process and the task, respectively.