• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.71-76
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• 2017

It is necessary to develop a service that meets various environmental requirements so that the Internet of things can be applied to the fourth industry in overall. This paper presents a method for extracting IoT devices information to change the current provider centric service provision environment in order to construct a user centered service provision environment for Web services. Also, it provides users to utilize the appropriate web services through taking advantage of IoT devices information. The existing service provision environment is focused on the method of selecting the service using the provider service information, thus, it is considered necessary for a user-oriented service search method to be in need. In this study, the service list is provided to the user by combining provider information and information extracted from IoT Devices. IoT information collection generates information by separating context information such as information between IoT devices and users and event information between devices through identifiers. In this paper, we propose a development of a user centric service environment by presenting users with a necessary service list through the proposed IoT information.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.52-57
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• 2009

Recently, the regular service of a terrestrial digital multimedia broadcasting(T-DMB) made faster distribution of T-DMB receiver. The problem of an illegal distribution is increasing owing to a large distribution of T-DMB receiver. In this paper, we propose a watermarking and encryption method on T-DMB bit-stream for a copy and Play control to prevent an illegal distribution of T-DMB contents. We implement our proposed method on a portable multimedia player (PMP) which has T-DMB receiver. The proposed method insert the encrypted information for control of copy and play after finding padding area of program map table (PMT) and program association table (PAT) from analysis of transport stream (TS) of T-DMB. In implementation result, we can control use of contents according to information of copy and play control. The proposed method can be used to content Protection software for blocking of an illegal distribution of T-DMB contents on a mobile T-DMB receivers.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.617-623
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• 2016

Recently, IoT technology has been applied to the control of appliances in the home, and information about temperature, humidity, etc. is collected and the application of the system to control the indoor environment automatically is increasing. Currently, the network configuration of IoT devices is mainly used to connect IoT devices to the Internet through wireless gateways. Since such a method is dependent on a gateway, there are limitations in providing various services. Therefore, this paper proposes an independent method of gateway by using IoT network without using gateway by applying long distance wireless communication technology. IoT devices using the proposed long distance wireless internet technology can connect to a remote server and provide mobility that can not be supported by existing methods, thereby providing more various services. The performance evaluation of the proposed network configuration method is compared with the delay time and the amount of data generated in the existing network method constituted by the gateway and the proposed network configuration method respectively. Experimental results show that the proposed method decreases the delay time and the amount of data generated by the gateway.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.759-768
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• 2012

This paper proposes a method to determine the elastic follow-up factors for the $C(t)$-integral under secondary stress. The rate of creep crack growth for transient creep is correlated with the $C(t)$-integral. Elastic follow-up behavior, which occurs in structures under secondary loading, prevents a relaxation of stress during transient creep. Thus, both the values of $C(t)$ and creep crack growth increase as increasing elastic follow-up. An estimation solution for $C(t)$ was proposed by Ainsworth and Dean based on the reference stress method. To predict the value of $C(t)$ using this solution, an independent method to determine the elastic follow-up factors for cracked bodies is needed. This paper proposed that the elastic follow-up factors for $C(t)$ can be determined by elastic-plastic analyses using the plastic-creep analogy. Finite element analyses were performed to verify this method.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.672-677
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• 2007

Recently, the new finite element method which uses NURBS as shape functions was proposed. It is very promising because it can directly use CAD data to describe geometry and discretize problem domain. In this case, CAE models are not approximated but represent exact geometry. So, it can contribute to more accurate results. In addition, it can greatly reduce CAE costs in that simulation models don't have to be made up independently. But in spite of these advantages, the method using NURBS have also some disadvantages. NURBS surface cannot be refined locally. T-splines are recently developed surface modeling technique. A T-spline surface is a NURBS surface with T-junctions and is defined by a control grid called T-mesh. The T-junctions enable T-spline surfaces to be refined locally. That is, it is possible to add a single control point to a T-spline control grid without propagating an entire row or column of control points and without altering the surface. In this research, the finite element analysis using T-splines is studied. In this analysis, CAD data are used directly for engineering analysis. Some problems with complex geometry are solved. And the results will be compared with ones of conventional FEM.

• Electrical & Electronic Materials
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• v.9 no.6
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• pp.600-604
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• 1996

High-T$_{c}$, superconducting wire is very important element for the application of electrical power systems. But it is very difficult to develope the long high T, wire with excellent properties. BiSrCaCuO multi-layer tapes are fabricated by a rolling method and pressing method sintered for several step at 840.deg. C. The critical current densities of 637 filament multi-layer tapes sintering 100 hours fabricated by the rolling method and pressing method are 1.3*10$^{4}$ A/cm$^{2}$ and 5.5*10$^{3}$ A/cm$^{2}$. The critical cur-rent densites of multi-layer tapes made by rolling method are found to be better than those fabricated by the powder-in-tube method and pressing process. As result, the rolling method is the best way to fabricated the multi-layer filament.t.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.3
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• pp.49-59
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• 2014

The Internet of Things(IoT) is a new promising technology made from a variety of technology. The IoT links the objects or people, then enabling anytime, anywhere connectivity for anything and not only for anyone. Social networking services have changed the way people communicate. Recently, new research challenges in many areas of Internet of things and social networking services are fired. In this paper, we propose things recommendation method using social relationship in social Internet of Things. We study previous researches about social network service, IoT, and social IoT. We proposed SIoT_FW(Social IoT Friendship Weight) using static and a dynamic social friendship weight. Also, our method considers four social relationships (Ownership Object Relationship, Co-Location Object Relationship, Social Object Relationship, Parental Object Relationship). We presents a music device scenario using our proposed method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.5
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• pp.579-587
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• 1999

The flow distribution characteristics in a complex duct system have been investigated in this paper by three means, namely experimental measurement, numerical simulation and the Extended T-method analysis. While the exit flow rates predicted by the three-dimensional CFD calculation and those given by the experiment show a close agreement, the results from the one-dimensional Extended T-method are found to differ from the experiment by -22.2% to 26.3% for the various exits. These discrepancies may be attributed to the underlying limitation concerning the fitting loss coefficients, which assume that the flow in front of the fittings is fully developed. It is proposed that, in order to analyse the three-dimensional flow distributions in a complex duct system by one-dimensional analysis such as the Extended T-method, further Improvements to the fitting loss coefficients should be made.

• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1177-1181
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• 2001

Objective : Thoracoscopic T2 sympathicotomy had been performed as a simple and effective method in treating palmar hyperhidrosis, but some patients are not satisfied with the result of sympathicotomy due to compensatory hyperhidrosis. Therefore, a more limited T2 sympathicotomy using 2mm endoscope was introduced. We made a comparison between conventional T2 sympathicotomy and limited T2 sympathicotomy on operative results and compensatory hyperhidrosis. Material and Method : From January 1998 to April 2000, 56 patients were treated by video assisted endoscopic thoracic sympathicotomy. Thirty patients of these underwent T2 sympathicotomy(Group A), and the remainders underwent limited T2 sympathicotomy(Group B). The limited T2 sympathicotomy is coagulation of the interganglionic fibers of T2 sympathetic ganglion on T2 rib head. The comparative analysis between two groups was based on the medical records and telephone interview results. Result : All patients were treated for excessive sweating on palms with 2mm endoscopic sympathicotmy. There were no mortalities, life-threatening complications except one recurrent patient who was treated successfully with reoperation( endoscopic sympathicotomy). Compensatory hyperhidrosis was common in group A. An individual satisfactory rate for the operations was higher in group B than in group A. Conclusion : The limited T2 sympathicotomy considered to be a more effective and less complicated method than the T2 sympathicotomy for the treatment of palmar hyperhidrosis.

• Mycobiology
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• v.37 no.4
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• pp.277-285
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• 2009

In this study, dual culture, poison agar, and direct methods were used to assess the ability of Trichoderma virens IMI-392430, T. pseudokoningii IMI-392431, T. harzianum IMI-392432, T. harzianum IMI-392433, and T. harzianum IMI-392434 to control Ceratocystis paradoxa, which causes the pineapple disease of sugarcane. The highest percentage inhibition of radial growth (PIRG) values were observed with T. harzianum IMI-392432 using two dual culture methods, 63.80% in Method I and 80.82% in Method II. The minimum colony overgrowth time was observed with T. harzianum IMI-392432 and the maximum was observed with T. pseudokoningii IMI-392431. Different concentrations of different day-old metabolites of Trichoderma isolates were tested against mycelial growth of C. paradoxa. The highest PIRG (84.685%) exhibited at 80% concentration of 30-day-old metabolites of T. harzianum IMI-392432 using the modified bilayer poison agar method. In the direct assay method the maximum mycelial growth weight (PIGW) was observed at the same concentration and the same day-old metabolites of T. harzianum IMI-392432. This study showed that Trichoderma isolates have a good antagonistic effect on C. paradoxa mycelial growth and T. harzianum IMI-392432 has the most potential to control the pineapple disease pathogen.