• Journal of KIISE:Databases
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• v.35 no.3
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• pp.231-242
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• 2008

W3C has selected OWL as a standard for Web ontology description and a necessity of research on storage models that can store OWL ontologies effectively has been issued. Until now, relational model-based storage systems such as Jena, Sesame, and DLDB, have been developed, but there still remain several issues. Especially, they lead inefficient query processing performance. The structural problems of their low query processing performance are as follow: Jena has a simple structure which is not normalized and also stores most information in a single table. It exponentially decreases the performance because of comparison with unnecessary information for processing queries requiring join operations as well as simple search. The structures of storages(e.g., Sesame) have been completely normalized. Therefore it executes many join operations for query processing. The storages require many join operations to find simply a specific class. This paper proposes a storage model to resolve the problems that the query processing performance is decreased because of non-normalization or complete normalization of the existing storages. To achieve this goal, we analyze the problems of existing storage models as well as relations of OWL elements and query patterns. The proposed model, defined with the analysis results, provides an optimal normalized structure to minimize join operations or unnecessary information comparison. For the experiment of query processing performance, a LUBM data sets are used and query patterns are defined considering search targets and their hierarchical relations. In addition, this paper conducts experiments on correctness and completeness of query results to verify data loss of the proposed model, and the results are described. With the comparative evaluation results, our proposal showed a better performance than the existing storage models.

• KIISE Transactions on Computing Practices
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• v.23 no.5
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• pp.284-292
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• 2017

With the development of Internet of Things (IoT) technology, the combination of ICT and medical services has been increasing to improve the quality of medical services. Using the IoTs, we can collect personal health information continuously in a patient's everyday life. We expect that this will improve the quality of medical service through analysis. However, the problem of ensuring the protection of personal information within the personal health information has been hampering the research, development, and application of such services. Other problems include lack of IoT devices and lack of user convenience for collecting health information about a patient's everyday life. Therefore, in this study, we construct a daily health information management service that can collect the health related information at any time and store this data in personal storage. This data is then only provided to the healthcare worker when necessary. We built a test bed for an IoT-based smart home platform and are currently conducting user experiments. Based on the results of this study, we are attempting to provide a high quality medical trial service based on daily health information through linkage with medical device manufacturers, medical clinics, insurance companies, etc. We expect the proposed health information management service will contribute to the revitalization of smart health care services via activating various health related IoT devices and analyzing daily health information.

• The KIPS Transactions:PartB
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• v.9B no.1
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• pp.1-6
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• 2002

Many customers consult the Internet before making purchase goods and using contents. The systems in the Internet could store a lot of data and classify the data into information to get relationship between a company and customers. To do that, let's consider a knowledge-assisted hybrid system that utilizes individually a customer's preference to make an optimal solution in the his/her decision making. The knowledge made by using the preference is employed to select an domain set appropriate to him/her business, and the process of selecting definitely provides the customer some benefits: elimination of discomfort from unknown information and reduction of costs and search time for forming an suitable domain set. To effectively adopt individual customer's preference and actively adapt change of business situation, this study propose an architecture of the system which includes rule presentations and an inference engine, and integrates a knowledge-based component into a quadratic programming component. In the experimental results, it is found that a knowledge-assisted hybrid system implemented by this idea is more flexible than existing systems in extension of knowledge about an customer's preference and goes beyond the traditional models.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.77-83
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• 2018

A modular robot that memorizes motion can be easily created and operated because it expresses by hand. However, since there is not enough storage space in the module to store the user-created operation, it is impossible to reuse the created operation, and when the modular robot again memorizes the operation, it changes to another operation. There is no main controller capable of operating a plurality of modular robots at the same time, and thus there is a disadvantage that the user must input directly to the modular robot. To overcome these disadvantages, a remote controller has been proposed that can be operated in the surrounding smart devices by designing web server and component based software using wired and wireless network. In the proposed method, various types of structures are created by connecting to a modular robot, and the reconstructed operation is performed again after storing, and the usefulness is confirmed by regenerating the stored operation effectively. In addition, the reliability of the downloaded trajectory data is verified by analyzing the difference between the trajectory data and the actual trajectory. In the future, the trajectory stored in the remote controller will be standardized using the artificial intelligence technique, so that the operation of the modular robot will be easily implemented.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.12
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• pp.1-7
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• 2008

Magnetic Tunneling Junction (MTJ) has been used as a nonvolatile universal storage element mainly in memory technology. However, according to several recent studies, magneto-logic using MTJ elements show much potential in substitution for the transistor-based logic device. Magneto-logic based on MTJ can maintain the data during the power-off mode, since an MTJ element can store the result data in itself. Moreover, just by changing input signals, the full logic functions can be realized. Because of its programmability, it can embody the reconfigurable magneto-logic circuit in the rigid physical architecture. In this paper, we propose a novel 3-bit arbitrary magneto-logic circuit beyond the simple combinational logic or the short sequential one. We design the 3-bit magneto-logic which has the most complexity using MTJ elements and verify its functionality. The simulation results are presented with the HSPICE macro-model of MTJ that we have developed in our previous work. This novel magneto-logic based on MTJ can realize the most complex logic function. What is more, 3-bit arbitrary logic operations can be implemented by changing gate signals of the current drivel circuit.

• Journal of Distribution Research
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• v.16 no.2
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• pp.25-56
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• 2011

A shifting of marketing paradigms from transaction to relationship has shown in many studies. Although there are many researches about relationship marketing, few of them focuses on relationship marketing combined with retail mix. This study define and measure customer relationship, and find the antecedents and consequences of the customer relationship. For the research, data were collected from 540 persons who are currently customers of five branches of E-mart and Homeplus in Seoul, Korea. Data analysis was performed under the AMOS 6.0. The results are summarized as following; Firstly, the relationship among elements of retail marketing mix and the relationship quality appears significant except communication program. This finding means that communication effect decreases at some point when communication program is excessive. Secondly, the relationship of customer relationship and three factors (frequent shopping intention, up-buying intention and recommend intention) are significant. Thus, this result supports the reasoning why discount stores make an effort to improve customer relationship. Thirdly, the relationship between share of wallet and two factors (frequent shopping intention and recommend intention) appears insignificant. Fourthly, the relationship between share of wallet and up-buying intention is significant. This result implies that up-buying intention is an important factor for discount stores, because up-buying intention is directly linked to financial performance of discount stores. Finally, the direct path between customer relationship and share of wallet is significant relation. For this reason, customer relationship should be managed consistently by discount stores.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.211-234
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• 2007

In e-business, XML is a major format of data and it is essential to efficiently process queries against XML data. XML query caching has received much attention for query performance improvement. In employing XML query caching, some efficient technique of cache replacement is required. The previous techniques considered as a replacement unit either the whole query result or the path in the query result. The former is simple to employ but it is not efficient whereas the latter is more efficient and yet the size difference among the potential victims is large, and thus, efficiency of caching would be limited. In this paper, we propose a new technique where the element in the query result is are placement unit to overcome the limitations of the previous techniques. The proposed technique could enhance the cache efficiency to a great extent because it would not pick a victim whose size is too large to store a new cached item, the variance in the size of victims would be small, and the unused space of the cache storage would be small. A technique of XML semantic cache replacement is presented which is based on the replacement function that takes into account cache hit ratio, last access time, fetch time, size of XML semantic region, size of element in XML semantic region, etc. We implemented a prototype XML semantic cache system that employs the proposed technique, and conducted a detailed set of experiments over a LAN environment. The experimental results showed that our proposed technique outperformed the previous ones.

• Journal of KIISE:Software and Applications
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• v.34 no.10
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• pp.918-928
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• 2007

The goal of this paper is to propose a new way to register CDA documents in CDR (Clinical Document Repository) that is proposed by the author earlier. One of the methods is to use a manifest archiving for seamless references and visualization of CDA related files. Another method is to enhance the CDA security level for supporting pseudonymization of CDA. The former is a useful method to support the bundled registration of CDA related files as a set. And it also can provide a seamless presentation view to end-users, once downloaded, without each HTTP connection. The latter is a new method of CDA registration which can supports a do-identification of a patient. Usually, CDA header can be used for containing patient identification information, and CDA body can be used for diagnosis or treatment data. So, if we detach each other, we can get good advantages for privacy protection. Because even if someone succeeded to get separated CDA body, he/she never knows whose clinical data that is. The other way, even if someone succeeded to get separated CDA header; he/she doesn't know what kind of treatment has been done. This is the way to achieve protecting privacy by disconnecting association of relative information and reducing possibility of leaking private information. In order to achieve this goal, the method we propose is to separate CDA into two parts and to store them in different repositories.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.104-111
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• 2008

The ECG is biomedical electrical signal occurring on the surface of the body due to the contraction and relaxation of the heart. This signal represents an extremely important measure for health monitoring, as it provides vital information about a patient's cardiac condition and general health. ECG signals are contaminated with high frequency noise such as power line interference, muscle artifact and low frequency nose such as motion artifact. But it is difficult to filter nose from ECG signal, and errors resulting from filtering can distort a ECG signal. The present study implemented a small-size and low-power ECG measurement system that can remove motion artifact for convenient health monitoring during daily life. The implemented ECG monitoring system consists of ECG amplifier, a low power microprocessor, bluetooth module and monitoring program. Amplifier was designed and implemented using low power instrumentation amplifier, and microprocessor was interfaced to the ECG amplifier to collect the data, process, store and feed to a transmitter. And bluetooth module used to wirelessly transmit and receive the vital sign data from the microprocessor to an PC at the receiving site. In order to evaluate the performance of the implemented system, we assessed motion artifact rejection performance in each situation with artificially set condition using adaptive filter.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.615-625
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• 2006

Nonvolatile memory technology is evolving continuously and commercial products such as FeRAM and PRAM are now challenging their markets. As NVRAM has properties of both memory and storage, it can store persistent data objects while allowing fast and random access. To utilize NVRAM for general purpose storing of frequently updated data across power disruptions, some essential features of the file system including naming, recovery, and space management are required while exploiting memory-like properties of NVRAM. Conventional file systems, including even recently developed NVRAM file systems, show very low space efficiency wasting more than 50% of the total space in some cases. To efficiently utilize the relatively expensive NVRAM, we design and implement a new extent-based space-thrifty file system, which we call NEBFS (NVRAM Extent-Based File System). We analyze and compare the space utilization of conventional file systems with NEBFS and validate the results with experimental results observed from running the file system implementations on a system with actual NVRAM installed as well as on systems emulating NVRAM. We show that NEBFS has high space efficiency compared to conventional file systems.