• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04b
• /
• pp.115-117
• /
• 2002

메모리 기술의 발전은 주기억장치 데이터베이스가 널리 사용될 수 있는 토대를 마련하였다. 주기억장치 데이터베이스에서는 주기억장치의 휘발성으로 인해 시스템이 파손될 경우 모든 데이터들을 잃어버리게 되므로 데이터베이스를 일관된 상태로 복구시켜주는 회복기법이 매우 중요하다. 본 논문에서는 비휘발성 메모리이면서도 RAM과 같이 빠른 접근속도를 가지는 FRAM과 같은 고성능 비휘발성 메모리를 이용하여 그림자 갱신과 로그 기반 백업을 실시함으로써 시스템 파손 후, 마른 복구를 제공하면서도 기존의 로그 기반 백업이 가지는 문제점을 해결하는 회복기법을 제안한다.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1993.04a
• /
• pp.530-539
• /
• 1993

철강업의 특성인 일관공정체제에서는 한 공정의 NECK 발생이 전공정의 UNBALANCE를 초래하여 생산성에 막대한 지장을 초래하게 된다. 본 연구의 목적은 기존의 노후설비를 작업방법이 다른 신설비로 교체함에 따라 신설공정의 복잡성으로 전.후공정에 대기가 예상되므로 simulation을 이용한 공정분석으로 문제점을 사전에 도출하여 최적의 조업기준을 제시코자 한다.

• The KIPS Transactions:PartD
• /
• v.12D no.1 s.97
• /
• pp.21-30
• /
• 2005

In mobile computing environments, a mobile host caches the data to use the narrow bandwidth efficiently and improve the response time. A server periodically broadcasts the update data for maintaining the cache consistency of a mobile host. However, a method for maintaining cache consistency using periodic invalidation report has a problem that defers the commit decision of a mobile transaction to guarantee its serializable execution. In this paper, we propose CCM-AD method that guarantees the serializable execution of a mobile transaction even in the case that it is executed using cached data. As CCM-AD method guarantees the serializable execution of mobile transactions by using the intersection between the data broadcast to mobile host and the data updated at server. Then the CCM-AD method can reduce the delay of commitment decision of a mobile transaction. Also our method can reduce the size of invalidation report.

• The KIPS Transactions:PartD
• /
• v.10D no.4
• /
• pp.647-654
• /
• 2003

The replication of data is used to increase its availability and to improve the performance of a system. The distributed database system has to maintain both the database consistency and the replica consistency. This paper proposes an algorithm which resolves the conflict of the operations by using the mechanism based on the structure that the replicas of each data item are hierarchically organized. Each update is propagated along the tree based on the fact that the root of each data item is the primary replica in partially replicated databases. The use of a hierarchy of data may eliminate useless propagation since the propagation can be done only to sites having the replicas. In consequence, the propagation delay of updates may be reduced. By using the timestamp and a compensating transaction, our algorithm resolves the non-serializability problem caused by the conflict of operations that can happen on the way of the update propagation due to the lazy propagation. This resolution also guarantees the data consistency.

• The Korean Journal of Financial Management
• /
• v.18 no.1
• /
• pp.83-106
• /
• 2001

본 연구에서는 1997년 말 외환위기 이후 $1998\sim1999$년에 걸쳐 행하여진 한국 은행산업 구조 조정의 성과를 실증적으로 분석하였다. 실증분석의 결과 위험수준이 높아 구조조정 기간에 금융감독당국으로부터 강한 경영개선 압력을 받을 가능성이 높은 은행들은 무수익여신, 부실여신비율 등 대출행위의 건전성 측면과 대출, 유가증권간의 투자비율, 그리고 유가증권 내 자산종목 간의 투자 비율 등 여러 가지 위험관련 변수들과 관련하여 측정된 건전화에 대한 동기면에서 외환위기 이전에 비하여 유의적이고 일관된 보다 높은 건전화에 대한 동기를 가지고 있었음을 볼 수 있었으며, 이러한 결과는 외환위기 이후의 은행권 구조조정 정책에 대한 어느 정도의 유효성을 보여 주는 결과로 사료된다. 또한 은행 집단별 분석에서는 구조조정 과정에서 퇴출 또는 우량은행에게 인수/합병된 부실은행들은 구조조정 이전의 기간에 그 외의 은행들 보다 위험추구에 대한 동기가 매우 강하였음을 볼 수 있었으나 이러한 위험추구의 동기가 우량은행에로의 인수/합병을 통하면서 상당히 감소하였음을 발견할 수 있었으며, 이러한 결과는 총표본에 대한 분석에서의 결과와 일관되게 외환위기 이후의 구조조정 정책에 대한 어느 정도의 유효성을 보여 주는 결과로 사료된다.

• Journal of Internet Computing and Services
• /
• v.7 no.5
• /
• pp.1-12
• /
• 2006

In mobile database environments, the efficient synchronization technique is required to maintain the consistency of replicated data because the same data can be replicated between so many different databases, In this paper, we propose a message digest based synchronization technique to maintain the consistency of replicated data between client databases and a server database in mobile environments. The proposed data synchronization technique has the advantage of generality aspect and extensibility aspect by using the tuple-based message digest output to detect the data conflicts.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.397-400
• /
• 2002

SAN(Storage Area Network)은 현재 폭발적으로 증가하는 데이터의 관리를 위해 대용량의 공유 저장장치를 사용하는 분산 환경의 고속 네트워크 저장 시스템이다. SAN 환경에서는 여러 호스트들에게 대용량 저장장치의 동시 접근을 허용함으로써 사용자에게 고 확장성과 신뢰성, 그리고 고 가용성을 제공해 준다. 그 결과 여러 호스트에 의해 공유되는 저장장치의 자료에 대한 비 일관성 문제가 발생하게 된다. 본 논문에서는 여러 호스트에 의해 동시 접근되는 공유 저장장치의 데이터 일관성을 유지하기 위한 락킹 모듈을 리눅스 운영체제 기반에서 구현하고, 그 성능을 평가한다.

• The KIPS Transactions:PartD
• /
• v.8D no.5
• /
• pp.593-604
• /
• 2001

A database sharing system (DSS) refers to a system for high performance transaction processing. In the DSS, the processing nodes are coupled via a high speed network and share a common database at the disk level. Each node has a local memory and a separate copy of operating system. To reduce the number of disk accesses, the node caches data pages and index pages in its memory buffer. In general, B-tree index pages are accessed more often and thus cached at more processing nodes, than their corresponding data pages. There are also complicated operations in the B-tree such as Fetch, Fetch Next, Insertion and Deletion. Therefore, an efficient cache consistency scheme supporting high level concurrency is required. In this paper, we propose cache consistency schemes using identifiers of index pages and page_LSN of leaf page. The propose schemes can improve the system throughput by reducing the required message traffic between nodes and index re-traversal.

• Journal of Korea Multimedia Society
• /
• v.11 no.7
• /
• pp.928-939
• /
• 2008

The grid database management system is used for large data processing, high availability and data integration by grid environment. It has a replica for processing performance and high availability in each node. The grid database has a problem of inconsistency, when the update is occurred with a coincidently frequent. To solve this problem, in this paper proposed a version management method for consistency in the grid database. Proposed version manager manages a version of each replica. The version manager keeps a consistency of update operation when is occurred at each node by using a pending queue and waiting queue. Also the node keeps a consistency using a priority queue. So, proposed method has stable and fast update propagation. The proposed method shows stable and faster update propagation than traditional method by performance evaluation.

• Korean Journal of Psychosomatic Medicine
• /
• v.24 no.2
• /
• pp.140-145
• /
• 2016

Objectives : Parental behavior is related to personality development and ego resilience in the childhood. The objective of this study was to identify the influence of parental behavior on ego resilience in Korean middle school student. Methods : Subjects were selected based on stratified multi-stage cluster sampling in Korea youth panel study 2013(Boy : N=1,075, Girl : N=1,033). We used Parental behavior inventory(PBI) to estimate parental behavior and the Ego resilience scale to estimate ego resilience. The data were statistically analyzed using a Pearson correlation analysis and regression analysis with the statistical package for the social sciences(SPSS). We considered differences to be significant when p<0.05. Results : A regression analysis showed that rational explanation, affection, Interest and inconsistency of the parental behavior domains influence ego resilience. Also rational explanation, affection and Interest of the parental behavior domains showed a significant positive correlation with ego resilience(r=0.24, r=0.31, r=0.22, p<0.01). In contrast to early childhood studies, inconsistency showed no significant correlation. Conclusions : Adolescents who had taken more rational explanation, interest and affection from their parents were more likely to have higher ego resilience. However, inconsistency of parental behavior showed no correlation with ego resilience of adolescents, which means that they are affected by several other factors than parental behavior. This study would be a basic research that could be a help to psychosocial approach in pediatric psychiatry.