• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.1
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• pp.41-55
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• 2007

The certificate is used to confirm and prove the user's identity in online finance and stocks business. A user's public key is stored in the certificate(for e.g., SignCert.der) and the private key, corresponding to public key, is stored in the private key file(for e.g., SignPri.key) after encryption using the password that he/she created for security. In this paper, we show that the certificate, deleted by the commercial certificate software, can be recovered without limitation using the commercial forensic tools. In addition, we explain the problem that the private key encryption password can be detected using the SignCert.der and the SignPri.key in off-line and propose the countermeasure about the problem.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.456-460
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• 2012

Privacy Protection Act of 30 March 2012 was performed. In general, personal information management to enhance security in the DB server has a security system but, PC for the protection of the privacy and security vulnerability analysis is needed to research on self-diagnosis. In this paper, from a PC to search information relating to privacy and enhance security by encrypting and for delete file delete recovery impossible. In pc found vulnerability analysis is Check user accounts, Checking shared folders ,Services firewall check, Screen savers, Automatic patch update Is checked. After the analysis and quantification of the vulnerability checks through the expression, enhanced security by creating a checklist for the show, PC security management, server management by semi-hwahayeo activates. In this paper the PC privacy and PC security enhancements a economic damage and of the and Will contribute to reduce complaints.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.126-133
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• 2015

According to the traditional precedent, if a beneficiary who completed a provisional registration as a result of reservation of trade which is a fraudulent act, then assigned the right acquired by the provisional registration to the third party who has no information of the process, and let the third party complete an additional registration transfer the provisional registration, and if the third party completed the main registration on the foundation of the provisional registration, the beneficiary cannot be the other party of the litigation requesting for the cancellation of registration of the provisional registration. As the result, an apprehension that the duty to recovery of the beneficiary could easily be acquitted of a charge has existed. But, it is considered as desirable that the judicial decision judged that the court recognized the qualification of the defendant as appropriate at this case, with a different view from the precedent, and then the defendant can file the litigation against the beneficiary, requesting for cancellation of the reservation of trade which is a fraudulent act.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.763-773
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• 2003

In this paper, we present a register renaming method for conditional execution out-of-order instruction issue microprocessors. Register renaming method reduces false data dependencies (write after read(WAR) and write after write(WAW)). To implement a conditional execution out-of-order instruction issue microprocessor using register renaming, we use a register file which includes both in-order state physical registers and look-ahead state physical registers to share all logical registers. And we design an in-order state indicator, a renaming state indicator, a physical register assigning indicator, a condition prediction buffer and a reorder buffer. As we utilize the above hardwares, we can do register renaming and trace the in-order state. In this paper, we present an improved register renaming method using smaller hardware resources than conventional register renaming method. And this method eliminates an associative lookup and provides a short recovery time.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.2
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• pp.29-38
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• 2010

Network Video Recorder becomes popular as a next generation surveillance system connecting all cameras and video server in network environment because it can provide ease of installation and efficient management and maintenance. But in case of data damage, the storage device in traditional NVR has no recovery scheme and it is disabled in processing real-time requests. In this paper, we propose an Reliable Storage using Parity and Mirroring scheme for improving reliability on storage device and maintaining system on realtime. RSPM uses a Liberation coding to recover damaged multimedia data and dynamic mirroring to repair corrupted system data and to maintain real-time operation. RSPM using the Liberation code is 11.29% lesser than traditional file system and 5.21% less than RSPM using parity code in terms of loss rate of damaged multimedia data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.204-226
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• 2018

Big data processing applications have been migrated into cloud gradually, due to the advantages of cloud computing. Hadoop Distributed File System (HDFS) is one of the fundamental support systems for big data processing on MapReduce-like frameworks, such as Hadoop and Spark. Since HDFS is not aware of the co-location of virtual machines in the cloud, the default scheme of block allocation in HDFS does not fit well in the cloud environments behaving in two aspects: data reliability loss and performance degradation. In this paper, we present a novel location-aware data block allocation strategy (LDBAS). LDBAS jointly optimizes data reliability and performance for upper-layer applications by allocating data blocks according to the locations and different processing capacities of virtual nodes in the cloud. We apply LDBAS to two stages of data allocation of HDFS in the cloud (the initial data allocation and data recovery), and design the corresponding algorithms. Finally, we implement LDBAS into an actual Hadoop cluster and evaluate the performance with the benchmark suite BigDataBench. The experimental results show that LDBAS can guarantee the designed data reliability while reducing the job execution time of the I/O-intensive applications in Hadoop by 8.9% on average and up to 11.2% compared with the original Hadoop in the cloud.

• The KIPS Transactions:PartB
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• v.16B no.3
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• pp.233-238
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• 2009

This paper presents an approach to the classifications of small size document using the instance-based feature filtering Relief-F algorithm. In the document classifications, we have not always good classification performances of small size document included a few features. Because total number of feature in the document set is large, but feature count of each document is very small relatively, so the similarities between documents are very low when we use general assessment of similarity and classifiers. Specially, in the cases of the classification of web document in the directory service and the classification of the sectors that cannot connect with the original file after recovery hard-disk, we have not good classification performances. Thus, we propose the Extended Relief-F(ERelief-F) algorithm using instance-based feature filtering algorithm Relief-F to solve problems of Relief-F as preprocess of classification. For the performance comparison, we tested information gain, odds ratio and Relief-F for feature filtering and getting those feature values, and used kNN and SVM classifiers. In the experimental results, the Extended Relief-F(ERelief-F) algorithm, compared with the others, performed best for all of the datasets and reduced many irrelevant features from document sets.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.859-868
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• 2018

Previous research related to recovering deleted data in database has been mainly based on transaction logs or detecting and recovering data using original source files by physical collection method. However there was a limit to apply if the transaction log does not exist in the server or it is not possible to collect the original source file because a database server owner does not permit stopping the database server because of their business loss or infringement at the scene. Therefore it is necessary to examine various collection methods and check the recoverability of the deleted data in order to handling the constraints of evidence collection situation. In this paper we have checked an experiment that the recoverability of deleted data in the original database source according to logical and physical collection methods on digital forensic investigation of Microsoft SQL Server database.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.397-403
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• 2020

With the convenience of real-time conversation, multimedia file and contact sharing services, most people use instant messenger, and its usage time is increasing. Because the messengers contain a lot of user behavior information data, in the digital forensic investigation, they can be very useful evidence to identify user behavior. However, some of useful data can be difficult to acquire or recognize because they are encrypted or deleted. Thus, in order to use the messenger data as evidence, the study of message decryption process and message recovery is essential. In this paper, we analyze the database encryption process of the instant messenger, MalangMalang Talkafe, and propose the method to decrypt it. In addition, we propose the methods to identify the deleted messages and recover from the volatile memory area.

• Biomedical Engineering Letters
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• v.8 no.4
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• pp.337-344
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• 2018

Additive manufacturing (AM) is an alternative metal fabrication technology. The outstanding advantage of AM (3D-printing, direct manufacturing), is the ability to form shapes that cannot be formed with any other traditional technology. 3D-printing began as a new method of prototyping in plastics. Nowadays, AM in metals allows to realize not only net-shape geometry, but also high fatigue strength and corrosion resistant parts. This success of AM in metals enables new applications of the technology in important fields, such as production of medical implants. The 3D-printing of medical implants is an extremely rapidly developing application. The success of this development lies in the fact that patient-specific implants can promote patient recovery, as often it is the only alternative to amputation. The production of AM implants provides a relatively fast and effective solution for complex surgical cases. However, there are still numerous challenging open issues in medical 3D-printing. The goal of the current research review is to explain the whole technological and design chain of bio-medical bone implant production from the computed tomography that is performed by the surgeon, to conversion to a computer aided drawing file, to production of implants, including the necessary post-processing procedures and certification. The current work presents examples that were produced by joint work of Polygon Medical Engineering, Russia and by TechMed, the AM Center of Israel Institute of Metals. Polygon provided 3D-planning and 3D-modelling specifically for the implants production. TechMed were in charge of the optimization of models and they manufactured the implants by Electron-Beam Melting ($EBM^{(R)}$), using an Arcam $EBM^{(R)}$ A2X machine.