• Proceedings of the IEEK Conference
• /
• 2002.07c
• /
• pp.1980-1983
• /
• 2002

When a feedback bridging fault is activated in a circuit, logical oscillation may occur at a signal line. If the oscillation appears, the fault may not be detected by logic testing. In order to detect such bridging faults, output logic values of the circuit should be measured at higher frequency than frequency of the logical oscillation. In this paper, a method fur estimating the maximum frequency of logical oscillation is proposed to detect such bridging faults in a circuit by logic testing. Also, it is shown by some experiments that such bridging faults can be detected by measuring output logic values at the frequency obtained by the method.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1999.10a
• /
• pp.254-262
• /
• 1999

실시간 시뮬레이션에서 주어지는 다양한 종류의 불연속적인 파라미터 값을 가지는 데이터 테이블에서 실시간의 제약 하에서의 검색을 수행하기 위해서는 최적의 기법이 요구된다. 실시간의 제약 하에서 최적 기법의 기준이 되는 것은 보통의 알고리즘들과는 달리 평균 속도가 아니라 worst case에서의 속도가 된다. 검색 알고리즘 들은 iteration을 거치게 되므로 총 탐색에 걸리는 시간은 iteration의 수(logical speed)와 1 probe를 수행하는 데 걸리는 시간(실제 수행속도)의 곱으로 정의된다. 본 연구에서 총 탐색에 걸리는 시간을 이론적으로 계산한 검색 속도 기존의 수행한 수치비교시험의 결과와 대체로 일치하였고, 이분 검색법이 iteration의 수와 실제 수행시간 모두에 있어서 가장 우수하다. 한편, 검색하고자 하는 파라미터 값의 dynamics를 이용하여 주어진 데이터 테이블 내의 검색 영역을 축소시키는 dynamic-window 개념을 도입하여 검색 알고리즘의 속도를 향상시킬 수 있었다. 이 개념의 도입은 데이터 테이블의 형태에 민감한 보간 검색법(interpolation method)과 그 응용 기법들에 대해 탁월한 효과를 나타내었다. 결론적으로 일반적 데이터 테이블에 있어서는 이분 검색법이 logical speed와 실제 수행속도가 우수하고, dynamic-window 개념을 도입한 보간 검색법과 그 변형들은 logical speed가 탁월하게 향상된다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.5
• /
• pp.922-931
• /
• 2012

This paper studies a series of logical topology reconfiguration processes corresponding to a series of traffic demand changes in a ship backbone network. The proposed reconfiguration technique is to minimize costly changes of traffic forwarding paths and minimize the average hop distance of traffic forwarding paths in terms of ship backbone network performance simultaneously. Performance evaluation is conducted to illustrate the efficiency of the proposed reconfiguration technique. It shows that the proposed reconfiguration technique yields efficient performance in the entire series of reconfiguration processes.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.511-512
• /
• 2007

변전소 자동화 시스템은 변전소 내의 주요 전기적 데이터들을 DB화 하여 그 트렌드 및 이벤트 내역을 관리하고 각종 제어를 수행하고 상태를 감시하는 시스템이다. 현재 전 세계적으로 IEC 61850 프로토콜을 적용하고 그 목적에 맞게 Interoperability를 구현하려는 노력이 진행되고 있으며 이에 맞추어 변전소 및 Utility에 적용되는 많은 시스템들이 IEC 61850의 적용에 박차를 가하고 있는 상황이다. 이에 따라 변전소 내의 주요기기중의 하나인 주 변압기에 설치되어 변압기의 상태를 감시하고 관리하는 IED인 변압기 Local Unit에 사용할 수 있는 새로운 IEC 61850 Local Unit의 Logical Node를 설계한다.

• Journal for History of Mathematics
• /
• v.25 no.4
• /
• pp.21-36
• /
• 2012

It is commonly believed that the model-theoretic account of logical consequence is originated from Tarski' s 1936 paper. But Etchemendy has denied this. This paper discusses and evaluates the recent controversies over whether the definition of logical consequence presented in Tarski' s paper is based on the fixed-domain conception or the variable-domain conception.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.465-474
• /
• 2008

This research presented an extraction method of a logical database to create a design form of stream-nose. The practical use of logical database is important for the expansion of thinking area with investigation of Form to create a stream nose. Firstly, We presented apply course with the method to draw the image database as a first step of a stream-nose design. secondly, extraction method of a character-line applied the image-layered technique was an objectified. Such course is for establishing a design process to create the original form of the stream nose.

• Journal of The Korean Association of Information Education
• /
• v.20 no.5
• /
• pp.465-474
• /
• 2016

The present study is aimed to find the effect of the activity of writing a structured reflection journal in the learning process of PBL-based programming on the logical thinking of elementary school students. To achieve the objective, this study carried out an experiment with 59 elementary school students in the 5th grade. They were divided into an experimental group and a control group. The experimental group was applied with PBL-based programming classes by learning step, including learning of the contents, its procedure, and the activities of writing a critical reflection journal while the control group received learning of PBL-based programming including unstructured reflection journal. And then the difference in their logical thinking was compared and analyzed before and after th experiment. The results demonstrated that the experimental group showed a significant difference in logical thinking before and after writing structured reflection journal (ANCOVA) at the significance level of .05, which evidenced writing a structured reflection journal has learning effect. Intergroup comparison of logical thinking also showed that there was learning effect. Those findings suggest that writing a structured reflection journal in the PBL-based programming learning for 5th grade elementary school students has a positive effect on the learners' logical thinking.

• Journal of Gifted/Talented Education
• /
• v.16 no.2
• /
• pp.167-191
• /
• 2006

The purpose of this study was to explore logical thinking abilities and metacognitive characteristics by student's giftedness and grade level. Furthermore, this study sought to present the practical basis for the promotion of students' abilities in self-driven learning as well as cognition. Average-ability students(n=199), economically disadvantage gifted students(n=133), and gifted students(n=111), who were sampled by two-step sampling procedures, responded the logical thinking ability test(Cho et al, 2006) and the questionnaire asking self-perception for 'metacognitive knowledge' and 'metacognitive control' abilities(Cho & Han, 2004). As the results, average-ability students showed less logical thinking abilities(in language, mathematics, and space) than gifted students. The logical thinking abilities had affected by giftedness, grade level and these interaction. And gifted students showed higher metacognitive control abilities in planning, monitoring, priority, and strategies of learning than average-ability students. However, there were no significant differences in metacognitive knowledge and metacognitive control abilities between economically disadvantaged gifted students and gifted students.

• Journal of KIISE:Computing Practices and Letters
• /
• v.10 no.1
• /
• pp.99-113
• /
• 2004

A new architecture called SAN(Storage Area Network) was developed in response to the requirements of high availability of data, scalable growth, and system performance. In order to use SAN more efficiently, most of SAN operating softwares support storage virtualization concepts that allow users to view physical storage devices attached to SAN as a large volume virtually h logical volume manager plays a key role in storage virtualization. It realizes the storage virtualization by mapping logical addresses to physical addresses. A logical volume manager also supports a snapshot that preserves a volume image at certain time and on-line reorganization to allow users to add/remove storage devices to/from SAN even while the system is running. To support the snapshot and the on-line reorganization, most logical volume managers have used table based mapping methods. However, it is very difficult to manage mapping table because the mapping table is large in proportion to a storage capacity. In this paper, we design and implement an efficient and flexible hybrid mapping method based on mathematical equations. The mapping method in this paper supports a snapshot and on-line reorganization. The proposed snapshot and on-line reorganization are performed on the reserved area which is separated from data area of a volume. Due to this strategy normal I/O operations are not affected by snapshot and reorganization. Finally, we show the superiority of our proposed mapping method through various experiments.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.6
• /
• pp.1359-1367
• /
• 2003

Through the historical and logical methodology, The historical development and extension of diagnostic concepts as chi(氣), shue(血), yin(陰), yang(陽) is analyzed. This study suggests the analystic methodology of diagnostic concepts, introduce the justification problem of oriental medical diagnosis, and is concluded with the problem of diagnostic concepts which should be modified and.