• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1688-1690
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• 2010

컴퓨터에서 안정성은 가장 중요시된다. 파일 시스템의 안정성이 문제가 되어 시스템이 다운되거나 여러 가지 문제가 발생할 경우, 데이터가 손상 되거나 데이터 복구가 불가능하게 될 수 있다. EXT3 파일 시스템은 이러한 문제점을 보안하기 위해 기존의 EXT2 파일 시스템에 저널링 기능이 추가된 파일 시스템이다. EXT3 파일 시스템은 매우 안정적이고, 기존의 EXT2 파일 시스템에서의 변경 과정이 쉽고 간단하여 일반적으로 많이 사용 되고 있는 저널링 파일 시스템이다. EXT3 파일 시스템은 기본적으로 ordered mode 를 사용하는데 메타데이터가 저널에 기록되는 추가적인 과정이 이루어져야 하기 때문에 성능의 저하가 발생한다. 본 논문에서는 ordered mode 에 압축 저장 기법을 적용하여 효율적인 공간 관리와 쓰기 속도가 향상된 ordered mode 저널링 기능을 제안하여 파일 시스템 기능을 개선하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.835-838
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• 2008

FAT 파일시스템은 거의 모든 운영체제에서 지원하기 때문에 임베디드 환경과 이동식 저장장치에서 NAND 플래시 메모리의 파일시스템으로 널리 사용되고 있다. 그러나 FAT 파일시스템은 하드디스크 특성에 맞게 설계되어 NAND 메모리의 특성에 맞지 않는 부분들이 있다. 이로 인한 파일 시스템의 신뢰성 문제를 해결하기 위하여 새로운 FAT 파일시스템 저널링 기능을 제안한다. 제안된 기능은 WindowsCE 환경에서 구현되었으며 동작을 다양한 크래시 환경에서 검사하였다.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.2
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• pp.296-316
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• 1998

The practical learning experience is the heart of nursing's professional program of study, have been the most widely disscussed and yet the least studied of all nursing education activities. The major goal of practical learning experience is to provide opportunities in realistic work settings that permit the nursing student to develop the knowledge, skill It attitudes of a beginning practitioner. The purpose of this study is to identify the experience of practical learning in the children's rehabilitation center by nursing students, to provide basic information for developing practical learning in pediatric nursing education. The study design was a descriptive study. Data were collected 74 cases of journaling which came from senior nursing students who cared for the handicapped children in P rehabilitation center from 24, August, 1997 to 29, Decmber, 29, 1998. The collected data were analyzed using the content analysis by Kim & Lee(1986), Kim(1987). The results are as follows : The content of practical learning in the children's rehabilitation center were classified with 5 domains. The domains were , , , , and .

• The Journal of Korean Academic Society of Nursing Education
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• v.20 no.2
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• pp.212-222
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• 2014

Purpose: The purpose of this study was to evaluate the nursing students' clinical judgment skills in simulation using Tanner's Clinical Judgment Model. Method: Forty-five teams of a total 93 nursing students participated in a post-operative patient care scenario using human patient simulator. Data were collected from students' responses in scenario and guided reflective journaling according to the framework of Tanner's model which comprised noticing, interpreting, responding, and reflecting on response. Data were analyzed using descriptive statistics. Results: The students' responses of the situation were in accordance with the goals of scenario, i.e. relieving patient' pain and preventing pulmonary complications. However, most of students needed clinical cues and focused on a given clue to solve the issues. They were lack of ability to collect additional information as well as connect the relevant clues in simulated clinical situation. Conclusion: The nursing students have difficulty in what they notice, how they interpret finding, and respond appropriately to the situation. The simulation training using Tanner's model could provide faculty and nursing students with an effective teaching and learning strategy to develop the clinical judgment skills.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.13-18
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• 2014

In this paer, mobile healthcare App is developed for mental health management focused on anger management for modern people who are under constant stress and various inner conflicts. We describe mechanism of anger and relations between disease and anger, and constitute contents of App to provide information of anger management. And finally we implement Web App. We build menu of App to be convenient to users to use. Implemented App provides many useful functions like information of anger and body, various self-test including A-type test, hostility test, and KMPI etc., journaling, anger management and community.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.4
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• pp.1-8
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• 2012

The NTFS journaling file($LogFile) is used to keep the file system clean in the event of a system crash or power failure. The operation on files leaves large amounts of information in the $LogFile. Despite the importance of a journal file as a forensic evidence repository, its structure is not well documented. The researchers used reverse engineering in order to gain a better understanding of the log record structures of address parts, and utilized the address for identifying object files to gain forensic information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.107-110
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• 2017

According to researches, while the speed of processor and network in embedded devices is fast enough to meet user requirement, the IO speed is recognized as the main performance bottleneck. Meanwhile it is known that more than 70 percent of IOs are issued from SQLite database. Many researches related SQLite performance optimization is based on WAL mode because WAL mode optimized for write IO performance. In this paper, I propose to optimize SQLite with Atomic Write in the Rollback Journal Mode, which is mainly used in Android and Tizen. I have observed that Atomic Write have a significant write performance improvement(300%) by reducing write, file sync operation and memory usage improvement(80%). Additionally it can block JOJ(Journaling of Journal) and extend the life of the flash memory.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.193-196
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• 2006

파일 시스템의 안정성에 문제가 생긴 경우, 파일 시스템의 동작이 중단되어 수정 중이던 데이터가 손실되거나 기존 데이터의 복구가 불가능하게 되는 상황이 발생 할 수 있다. 데이터의 종류에는 파일의 데이터와 같이 데이터 자체가 중요한 내용을 담고 있는 것과 파일의 데이터를 관리하기 위한 정보를 담고 있는 데이터가 있는데 후자를 메타데이터라고 한다. 단순히 파일의 데이터가 손실된 경우에 약간의 데이터 손실이 발생할 수는 있지만, 파일 시스템은 정상적으로 동작 할 수 있다. 하지만 메타데이터가 손상된 경우에는 파일 시스템이 볼륨에 접근조차 할 수 없게 되어 볼륨 내의 모든 파일을 접근할 수 없게 된다. 이러한 문제점들을 극복하기 위해 DualFS [8], log-structured 파일 시스템 [10], XFS [9] 등의 다양한 저널링 파일 시스템들이 제안되었다. 그 중 Ext$_3$ 파일 시스템은 가장 안정적이고 치명적인 문제점이 없는 것으로 알려져 있다.[7] 하지만 Ext$_3$ 파일 시스템에서 기본적으로 사용되고 있는 ordered mode 저널링은 메타데이터의 복사가 이루어져야 하기 때문에 속력의 저하가 발생한다. 본 논문에서는 ordered mode의 메타데이터의 복사 작업이 필요 없는 개선된 ordered mode 저널링을 제안한다.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.142-150
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• 2021

Open-channel SSD is a new type of Solid-State Disk (SSD) that improves the garbage collection overhead and write amplification due to physical constraints of NAND flash memory by exposing the internal structure of the SSD to the host. However, the host-level Flash Translation Layer (FTL) provided for open-channel SSDs in the current Linux kernel consumes host memory excessively because it use page-level mapping table to translate logical address to physical address. Therefore, in this paper, we implemente a selective mapping table loading scheme that loads only a currently required part of the mapping table to the mapping table cache from SSD instead of entire mapping table. In addition, to increase the hit ratio of the mapping table cache, filesystem information and mapping table access history are utilized for cache replacement policy. The proposed scheme is implemented in the host-level FTL of the Linux kernel and evaluated using open-channel SSD emulator. According to the evaluation results, we can achieve 80% of I/O performance using the only 32% of memory usage compared to the previous host-level FTL.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.97-106
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• 2014

There is a lot of interest in the data storage and backup systems according to increasing the data intensive services and related user's data. The overhead of backup performance in massive storage system is a critical issue because the traditional incremental backup strategies causes the time consuming bottleneck in the SAN environment. The SANique Smart Vault system is a high performance backup solution with data de-duplication technology and it guarantees these requirements. In this paper, we describe the architecture of SANique Smart Vault system and illustrate efficient delta incremental backup method based on journaling files. We also present the record-level data de-duplication method in our proposed backup system. The proposed forever incremental backup and data de-duplication algorithms are analyzed and investigated by performance evaluation of other commercial backup solutions.