• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.5
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• pp.1107-1115
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• 1997

In this paper, we propose an error concealment method to recovre damaged block-based image coding schemes. Channel errors during transmission of image data such as bit errors or cell loss result in damaged image blocks in the reconstructed images. To recover damaged blocks is to estimate them using the correctly received or undamaged neighborhood information. In the proposed method, an overcomplete basis for a large block containing a damaged block at its center is introduced and damaged blocks are recovered by sequentially projecting the known neighborhood information onto the overcomplete basis function. Computer simulations show that the proposed algorithm outperforms the conventional method in subjectie recovery qualities as well as objective ones.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.208-208
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• 2004

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.506-507
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• 2015

Our scheme going to use the advanteges of shadow technical and use it in flash memory. With our scheme we can maintain the system from corruption by making a capy table for table mappinng. It is make us to recover the data easily when something unusually happen to the system.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.1
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• pp.10-18
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• 2014

From the perspective of reducing the sampling cost of color images at high resolution, block-based compressive sensing (CS) has attracted considerable attention as a promising alternative to conventional Nyquist/Shannon sampling. On the other hand, for storing/transmitting applications, CS requires a very efficient way of representing the measurement data in terms of data volume. This paper addresses this problem by developing a measurement-coding method with the proposed customized Huffman coding. In addition, by noting the difference in visual importance between the luma and chroma channels, this paper proposes measurement coding in YCbCr space rather than in conventional RGB color space for better rate allocation. Furthermore, as the proper use of the image property in pursuing smoothness improves the CS recovery, this paper proposes the integration of a low pass filter to the CS recovery of color images, which is the block-based ${\ell}_{20}$-norm minimization. The proposed coding scheme shows considerable gain compared to conventional measurement coding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3B
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• pp.202-211
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• 2002

Because wireless links are subject to disturbances and failures, it is important to support disconnected operations in mobile computing. Many schemes have been proposed to support the efficient disconnected operations. In this paper, we analyze and measure the computation time including disconnected operations to evaluate the performance of mobile computing on error prone wireless links. Mobile computation consists of three states: data hoarding, disconnected operation, and block states. We estimate the computation time using various parameters; error rate and recovery rate of wireless link, hoarding overhead, logging overhead, and reintegration overhead, etc. We can choose efficient strategies for disconnected operations and predict the performance using the results of this analysis.

• ETRI Journal
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• v.37 no.5
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• pp.979-989
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• 2015

Recently, Hou and others introduced a (2, n) block-based progressive visual cryptographic scheme (BPVCS) in which image blocks can be gradually recovered step by step. In Hou and others' (2, n)-BPVCS, a secret image is subdivided into n non-overlapping image blocks. When t ($2{\leq}t{\leq} n$) participants stack their shadow images, all the image blocks associated with these t participants will be recovered. However, Hou and others' scheme is only a simple 2-out-of-n case. In this paper, we discuss a general (k, n)-BPVCS for any k and n. Our main contribution is to give two constructions (Construction 1 and Construction 2) of this general (k, n)-BPVCS. Also, we theoretically prove that both constructions satisfy a threshold property and progressive recovery of the proposed (k, n)-BPVCS. For k = 2, Construction 1 is reduced to Hou and others' (2, n)-BPVCS.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.4
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• pp.123-128
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• 2020

As the use of digital devices is becoming more commonplace, digital forensics techniques recover data to collect physical evidence during the investigation. Among them, the file forensics technique recovers deleted files, therefore, it can recover the database by recovering all files which compose the database itself. However, if the record is deleted from the database, the modified record contents will not be restored even if the file is recovered. For this reason, the database forensics technique is required to recover deleted records. Database forensics obtains metadata from database configuration files and recovers deleted records from data files. However, record recovery is difficult if database metadata such as block size cannot be obtained from the database. In this paper, we propose three methods for obtaining block size, which is database metadata. The first method uses the maximum size of free space in the block, and the second method uses the location where the block appears. The third method improves the second method to find the block size faster. The experimental results show that three methods can correctly find the block size of three DBMSes.

• The Korean Journal of Pain
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• v.8 no.2
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• pp.279-285
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• 1995

Extradural block is a form of treatment described as early as the beginning of the present centuries. It has since had positive criticism from a number of authors in different countries. Epidural injections of steroids with or without local anesthetic have become an occasional method of conservative treatment in sciatica & lumbago, especially in acute case. We assess the results of continuous epidural block with steroids and local anesthetics in sciatica & lumbago. From July 1994 to June 1995, we treated 46 case of lumbago and sciatica using continuous epidural block with steroids and local anesthetics. After placement of 17-Gauge Tuohy needle in the epidural space by the technique of loss of resistance, 0.25% bupivacaine 5 cc and triamcinolone 40 mg was administered and then epidural catheter was placed and connected to multiday infusor(Paragon) using 1% lidocaine with continuous infusion rate of 1 ml/hour. Usually, the catheter was removed after 1~2 weeks and then treated with the physical therapy. At the time of patient's discharge, 69.5% of all cases showed excellent or good results. Of particular note, 26 of the 46 cases were followed up by telephone. At present, in using Of particular note, 26 of the 46 cases were followed up by telephone. At present, in using continuous epidural block procedure, a relief in symptoms showed in 65.5% of these 26 cases. Continuous epidural block provides shortening of the recovery time from pain, avoidance of long period bed rest and early physical therapy and exercise. Therefore, continuous epidural block is simple and safe in the treatment of lumbago and sciatica, especially in acute phase.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.589-596
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• 2002

Tn the data transmission service of the mobile host, it is needed to reduce the bandwidth and to make a reliable error recovery. there are two appropriate methods in that. One is FEC which retransmits the parity of error recovery, in case of happening of the loss after forming the parity of error recovery by grouping original data. The other is local recovery based on server which can block the implosion of transmission. The use of FEC and local recovery based on server at the same time enables the reliable multicast. This paper suggests algorithm that recovers the loss by FEC and local recovery based on server through the solution of the problems about triangle routing, tunnel convergence by dividing mobile host into two parts-the sender and the receiver. This model about the loss of algorithm tested the efficiency of performance by the homogeneous independent loss, the heterogeneous independent loss, the shared source link loss model. The suggested algorithm confirms effectiveness in the environment where there are much data and many receivers in mobile host.

• Korean Journal of Occupational Health Nursing
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• v.21 no.3
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• pp.317-325
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• 2012

Purpose: This study was to examine the effects of noise block on anxiety and vital sign of gynecologic laparoscopic surgery. Methods: The data were collected from March to May 2011. Participants were sixty patients with gynecologic laparoscopic surgery, divided into 30 of experimental group and 30 of control group at C University hospital located in I city. The day before surgery, demographic data, trait-state anxiety and vital signs were measured at ward. After noise block, the data were measured using VAS anxiety and vital signs before anesthesia and in recovery room. And then state anxiety and vital signs were measured in ward after surgery. The data were analyzed by $x^2$-test, t-test, repeated measured ANOVA and Bonferroni comparison method using SPSS/WIN 19.0. Results: After conducting noise block program, the experimental group showed significant decrease in state anxiety and heart rate compared to those of the control group. But there were not significant differences in VAS anxiety, systolic pressure and diastolic pressure between two groups. Conclusion: This program can be regarded as an effective nursing intervention for the management of anxiety with gynecologic laparoscopic surgery.