• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.984-995
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• 1996

Data errors according to the various noises caused in the satellite communication links are corrected by the Viterbi decoding algorithm which has extreme error correcting capability. In this paper, we designed and implemented a convolutional encoder and Viterbi decoder ASIC which is used to encode the input data at the transmit side and correct the errors of the received data at the receive side for use in the VSAT communication system. And this chip may be used in any BPSK, QPSK, or OQPSK transmission system. The ambiguity resolver corrects PSK modem ambiguities by delaying, interting, and/or exchanging code symbol to restore their original sequence and polarity. In case of previous decoding system, ambiguity state(AS) of data is resolved by external control logic and extra redundancy data are needed to resolve AS. But, by adopting decoder proposed in this paper, As of data is resolved automatically by internal logic of decoder in case of continuous mode, and by external As line withoug extra redudancy data in burst mode case. So, decoding parts are simple in continuous mode and transmission efficiency is increased in bust mode. The features of this chip are full duplex operation with independent transmit and receive control and clocks, start/stop inputs for use in burst mode systems, loopback function to verify encoder and decoder, and internal or external control to resolve ambinguity state. For verification of the function and performance of a fabricated ASIC chip, we equiped this chip in the Central and Remote Earth Station of VSAT system, and did the performance test using the commerical INTELSAT VII under the real satellite link environmens. The results of test were demonstrated the superiority of performance.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.799-812
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• 2001

As XML become more popular for encoding data and exchanging format on the web, recent work on processing XML Document in DBMS has been performed. However, there is no formal data model for XML, and there is lack of research on XML algebra for processing complex XML query and even the mediators have many restrictions. Therefore, this paper proposes formal data model and algebra based on directed edge labeled graph for XML query. To implement algebra, not only algorithms of operation for algebra are presented, but also they are implemented using access method and path index based on RDBMS or ORDBMS. In particular, experiments to show the effectiveness of the implemented algebra are performed on XML documents on EST data which are semistructured data.

• The KIPS Transactions:PartD
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• v.16D no.5
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• pp.643-650
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• 2009

As one of typical techniques for acquiring bio-information, microarray has contributed greatly to development of bioinformatics. Although it is established as a core technology in bioinformatics, it has difficulty in sharing and storing data because data from experiments has huge and complex type. In this paper, we propose a new method which uses the feature that microarray data format in MAGE-ML, a standard format for exchanging data, has frequent structurally similar patterns. This method constructs compact database by simplifying MAGE-ML schema. In this method, Inlining techniques and newly proposed classification techniques using structural similarity of elements are used. The structure of database becomes simpler and number of table-joins is reduced, performance is enhanced using this method.

• Hwankyungkyoyuk
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• v.24 no.2
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• pp.54-69
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• 2011

The objectives of this study were to investigate the need for school uniform recycling and to review the school uniform recycling-related education. 231 female high school students were asked to answer regarding the wearing state of school uniform and their satisfaction level. 10 subjects in middle school technology/home economy were evaluated. As the result, the students wore 1~2 pieces of school uniform, which showed that it was hard to keep them clean by washing them often. The satisfaction level of school uniform was not high, The lowest item was the price. Therefore, to increase the satisfaction level of the school uniforms and also to increase the sanitary level of the school uniforms, it was advisable to purchase a recycled school uniform at cheaper prices to have an extra set. For a vitalization of the recycled school uniforms, the middle school technology/home economy subjects were reviewed. In the topic of "clothing acquisition plan and purchase", the themes of planned purchase, overconsumption of clothing and environmental pollution were discussed and included preferable behaviors for disposal. The topic of "clothing manufacturing and recycling" listed recycling the clothes that are not worn or exchanging them with neighbors as well as suggesting methods to illicit environment-friendly behaviors and carrying them out. However, some textbooks only briefly explained the methods of recycling and more detailed and practical methods need to be suggested in the curriculum. In addition, the contents regarding the environment in the clothing topic need to be supplemented more and more changes, such as related education plans or data development, are required. The objectives of this study were to investigate the need for school uniform recycling and to review the school uniform recycling-related education. 231 female high school students were asked to answer regarding the wearing state of school uniform and their satisfaction level. 10 subjects in middle school technology/home economy were evaluated. As the result, the students wore 1~2 pieces of school uniform, which showed that it was hard to keep them clean by washing them often. The satisfaction level of school uniform was not high, The lowest item was the price. Therefore, to increase the satisfaction level of the school uniforms and also to increase the sanitary level of the school uniforms, it was advisable to purchase a recycled school uniform at cheaper prices to have an extra set. For a vitalization of the recycled school uniforms, the middle school technology/home economy subjects were reviewed. In the topic of "clothing acquisition plan and purchase", the themes of planned purchase, overconsumption of clothing and environmental pollution were discussed and included preferable behaviors for disposal. The topic of "clothing manufacturing and recycling" listed recycling the clothes that are not worn or exchanging them with neighbors as well as suggesting methods to illicit environment-friendly behaviors and carrying them out. However, some textbooks only briefly explained the methods of recycling and more detailed and practical methods need to be suggested in the curriculum. In addition, the contents regarding the environment in the clothing topic need to be supplemented more and more changes, such as related education plans or data development, are required.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.175-178
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• 2008

While read operation on flash memory is fast and doesn't have any constraints, flash memory can not be overwritten on updating data, new data are updated in new area. If data are frequently updated, garbage collection, which is achieved by erasing blocks, should be performed to reclaim new area. Hence, because the number of erase operations is limited due to characteristics of flash memory, every block should be evenly written and erased. However, if data with access locality are processed by cost benefit algorithm with separation of hot block and cold block, though the performance of processing is high, wear-leveling is not even. In this paper, we propose CB-MG (Cost Benefit between Multi Group) algorithm in which hot data are allocated in one group and cold data in another group, and in which role of hot group and cold group is exchanged every period. Experimental results show that performance and wear-leveling of CB-MG provide better results than those of CB-S.

• The KIPS Transactions:PartD
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• v.13D no.3 s.106
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• pp.299-308
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• 2006

As recently XML is becoming the standard of exchanging web documents and public documentations, XML data are increasing in many areas. To retrieve the information about XML documents efficiently, the semantic web based on the ontology is appearing. The existing ontology has been constructed manually and it was time and cost consuming. Therefore in this paper, we propose the semi-automatic ontology generation technique using the data mining technique, the association rules. The proposed method solves what type and how many conceptual relationships and determines the ontology domain level for the automatic ontology generation, using the data mining algorithm. Appying the association rules to the XML documents, we intend to find out the conceptual relationships to construct the ontology, finding the frequent patterns of XML tags in the XML documents. Using the conceptual ontology domain level extracted from the data mining, we implemented the semantic web based on the ontology by XML Topic Maps (XTM) and the topic map engine, TM4J.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.131-139
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• 2012

The cloud storage has the client lend and use the device as a form of service rather than owning it, and thus the client pays the charge for the service that he or she actually uses, making it beneficial over the self-managed data center. When the storage service is provided on public cloud, however, the clients does not have any control over the user data, which brings a problem of violating data confidentiality. In this paper, we propose a gateway that works between the public cloud and the client for the purpose of guaranteeing the confidentiality of user data stored in cloud. The gateway encrypts or decrypts, and then delivers the user data without the client's intervention. In addition, it provides the function of exchanging keys to allow the client to access through another gateway. The proposed idea has been tested on a commercial public cloud and verified to satisfy security and compatibility.

• Journal of Internet Computing and Services
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• v.11 no.6
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• pp.123-133
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• 2010

XML has been become the new standard for publishing and exchanging data on the Web. However, most business data is still stored and maintained in relational database management systems. As such, there is an increasing need to efficiently publish relational data as XML data for Internet-based applications. The most important issue in the transformation is to reflect structural and semantic relations of RDB to XML schema exactly. Most transformation approaches have been done to resolve the issue, but those methods have several problems. In this paper, we discuss algorithm in transforming a relational database schema into corresponding XML schema in XML Schema. We aim to achieve not only explicit/implicit referential integrity relation information but also high level of nested structure while introducing no data redundancy for the transformed XML schema. To achieve these goals, we propose a transformation model which is redundancy free and then we improve the XML Schema structure by exploring more nested structure.

• The Journal of Society for e-Business Studies
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• v.9 no.3
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• pp.57-77
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• 2004

The main purpose of this study is to develop XML schemata and related STEP model for sharing construction drawings information. To achieve this purpose, the authors have developed a drawing information model based on STEP/AP202, the data searching mechanism based on STEP, and XML schemata for sharing and exchanging information between vector data and non-shape attribute information. Finally, the authors have suggested the way of sharing drawing information through linked STEP data and a XML schema using test cases of construction material information and code checking. The study shows a way of optimized managing and sharing construction information through the drawing information and external data for the whole building life-cycle, from early design stage to the construction stage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.315-320
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• 2009

Since flash memory can not be overwritten on updating data, new data are updated in new area and old data should be invalidated and erased for garbage collection. With develop of flash memory technology, capacity of flash memory is rapidly increasing. It increases rapidly execution time of CPU to search an entire flash memory of large capacity when choosing the block to erase in garbage collection. To solve the problem that is increasing execution time of CPU, flash memory is partitioned into several groups, the block to erase in garbage collection is searched within the corresponding group. In workload of access locality, we enhanced wear-leveling within group by allocating hot data to hot group and cold data to cold group respectively and enhanced wear-leveling among groups by exchanging periodically hot group and cold group.