• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1452-1460
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• 2000

A series of papers in recent literature on logical topology design for wavelength routed optical networks have proposed mathematical models and solution methods unifying logical topology design wavelength assignment and traffic routing. The most recent one is by Krishnaswamy and Sivarajan which is more unifying and complete than the previous models. Especially the mathematical formulation is an integer linear program and hence regarded in readiness for an efficient solution method compared to the previous nonlinear programming models. The solution method in [7] is however elementary one relying on the rounding of linear program relaxation. When the rounding happens to be successful it tends to produce near-optimal solutions. In general there is no such guarantee so that the obtained solution may not satisfy the essential constraints such as logical -path hop-count and even wavelength number constraints. Also the computational efforts for linear program relaxation seems to be too excessive. In this paper we propose an improved and unifying solution method based on the same to be too excessive. In this paper we propose an improved and unifying solution method based on the same model. First its computation is considerably smaller. Second it guarantees the solution satisfies all the constraints. Finally applied the same instances the quality of solution is fairly competitive to the previous near optimal solution.

• The KIPS Transactions:PartD
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• v.18D no.3
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• pp.157-168
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• 2011

Recently flash memory has been being utilized as a main storage device in mobile devices, and flashSSDs are getting popularity as a major storage device in laptop and desktop computers, and even in enterprise-level server machines. Unlike HDDs, on flash memory, the overwrite operation is not able to be performed unless it is preceded by the erase operation to the same block. To address this, FTL(Flash memory Translation Layer) is employed on flash memory. Even though the modified data block is overwritten to the same logical address, FTL writes the updated data block to the different physical address from the previous one, mapping the logical address to the new physical address. This enables flash memory to avoid the high block-erase cost. A flashSSD has an array of NAND flash memory packages so it can access one or more flash memory packages in parallel at once. To take advantage of the internal parallelism of flashSSDs, it is beneficial for DBMSs to request I/O operations on sequential logical addresses. However, the B-tree structure, which is a representative index scheme of current relational DBMSs, produces excessive I/O operations in random order when its node structures are updated. Therefore, the original b-tree is not favorable to SSD. In this paper, we propose AS(Always Sequential) B-tree that writes the updated node contiguously to the previously written node in the logical address for every update operation. In the experiments, AS B-tree enhanced 21% of B-tree's insertion performance.

• 대한공업교육학회지
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• v.31 no.2
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• pp.64-82
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• 2006

This study investigated what effects multiple intelligence, through which the diverse intelligence abilities of a learner are identified, has on technological problem solving ability according to sex. And it was carried out to present a way to reduce the gap between boys and girls in technological problem solving ability. The subject was 833 middle school students in the third grade (boys: 423, girls: 410) whose schools are located in a megalopolis or more large area. And the instruments developed by Yong-Lyn Moon(2001) and in CRESST(1998) were used. The results of this study are as follows. First, it appeared that there were statistically meaningful differences at six items in multiple intelligence between boys and girls. The six items were bodily-kinesthetic intelligence, logical-mathematical intelligence, naturalistic intelligence, musical intelligence, interpersonal intelligence, and introspective intelligence. Second, in technological problem solving ability, it appeared that boys and girls showed statistically meaningful differences at self-regulation and problem solving strategy. Third, it appeared that logical-mathematical intelligence, linguistic intelligence, introspective intelligence, and natural intelligence had an effect on boys in the way of self-regulation and logic-mathematical intelligence, introspective intelligence, naturalistic intelligence, and linguistic intelligence did on girls. Fourth, it appeared that logical-mathematical intelligence, musical intelligence, and bodily-kinesthetic intelligence had an effect on boys in the way of problem solving ability and linguistic intelligence and musical intelligence had on girls. Fifth, it appeared that logical-mathematical intelligence did an effect on both sexes in drawing up the understanding of contents. On the basis of the results of this study, the area related to multiple intelligence directly or indirectly should be developed in the course of designing the primary and secondary curriculums to reduce the gap between boys and girls in multiple intelligence. With these efforts, the scholastic attainments gap caused by the difference of multiple intelligence will be overcome.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.268-278
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• 2004

In this paper, we describe our experience in the design and implementation of the SMART file system to handle multimedia workload. Our work has three design objectives: (ⅰ) efficient support for sequential workload, (ⅱ) avoiding disk fragmentation, (ⅲ) logical unit based file access. To achieve these three objectives, we develop a file system where a file consists of linked list of Data Unit Group. Instead of tree like structure of the legacy Unix file system, we use single level file structure. Our file system can also access the file based upon the logical unit which can be video frame or audio samples. Data Unit Group is a group of logical data units which is allocated continuous disk blocks. At the beginning of each Data Unit Group, there exists an index array. Each index points to the beginning of logical data units, e.g. frames in the Data Unit Group. This index array enables the random access and sequencial access of semantic data units. SMART file system is elaborately tailored to effectively support multimedia workload. We perform physical experiments and compare the performance of SMART file system with EXT2 file system and SGI XFS file system. In this experiment, SMART file system exhibits superior performance under streaming workload.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.259-266
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• 2021

This study is a study to systematize the R&D activities of social enterprises to derive a logical model of the R&D support policy, and aims to systematize the R&D activities based on the R&D demand survey and R&D activity analysis of social enterprises. R&D activities of social enterprises are at an early stage or are not systematic compared to general enterprises, so the process modeling method is used to group detailed activity elements to standardize and systemize them. As a result of the research, social enterprises are aware of the necessity and importance of R&D activities to secure competitiveness of products and services to increase social value, and because of their lack of R&D experience and capabilities, R&D specialized institutes (R&D planning institutes, government-funded research institutes), Universities, etc.) and are expected to improve R&D capabilities. The performance indicators of social enterprise R&D activities are derived in units of input-process-performance indicators through demand survey, activity analysis, and in-depth interview (FGI), and the logical model of R&D support policy is in the areas related to business strategy and performance.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.324-329
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• 2003

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.201-217
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• 2004

In this research, OIL (Ontology Inference Layer), one of the ontology language, is applied for classifying product data systematically, defining concepts, and establishing relationship between concepts. By transforming steel product data into XML documentation and managing them, knowledge management based on the logical structure of documents is possible.

• ETRI Journal
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• v.9 no.1
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• pp.104-117
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• 1987

본고는 TDX-1의 기능 및 시스팀 시험을 시험전용 컴퓨터를 사용하여 자동화시켜, 체계적이고 능률적인 시험수행과 test quality를 보장할 수 있는 test environment system에 대해 그 기능들의 설명과 그에 대한 implement 방법 및 logical, physical structure를 소개하였다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.282-288
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• 2000

This paper describes the basic concept and processes underlying human design technology, and outlines Kansei design base on this logical approach.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.7-12
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• 1994

This paper describes an outline of pseudorandom M-sequence and its applications to measurement and control engineering. At first, generation and properties of M-sequence is briefly described and then its applications to delay time measurement, information transmission by use of M-array, two dimensional positioning, fault detection of logical circuit, fault detection of RAM, linear and nonlinear system identification.