• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3A
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• pp.293-302
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• 2004

Wireless LAN is a rather mature communication technology that connects mobile terminals. A typical wireless LAN system is composed of one AP and more than one terminals, which is called a BSS. Terminals near to an AP can receive high rate data but terminals far from an AP may not receive data with guaranteed high speed rate because received signal strength is weakened. This paper proposes a method to allow high speed data transmission by grouping terminals and using part of wireless terminals as repeaters. We compare and analyze proposed grouping algorithms based on Depth First Search and Breadth First Search via simulations. A grouping algorithm based on Breadth First Search is shown to be more effective in term of efficiency and coverage.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.89-97
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• 2015

In this paper, we propose a handoff method supporting LBS (Location Based Services) Information in mobile clouding environment. In mobile clouding computing, handoff delay and re-authentication is occurred. A mobile node needs re-authentication procedure from cloud server whenever it arrives new AP. But Using of location information of node enables to reduce delay time due to re-authentication. To reduce re-authentication delay time, proposed method stores location information of APs on WiFi based location server to complement. GPS-based technology which can't receive satellite signal in indoor and then node collects location information of AP at handoff time. And also enables to process LBS without increasing handoff delay by splitting the process of handoff from process of requesting location information. For analysis of proposed method, We analyze handoff delay and location information process time and have compared previous handoff method in cloud environment. We confirmed that proposed method shows lower delay time without increasing LBS process time than previous method because node receives location information from location information server when handoff is occurred.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.463-469
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• 2014

We propose an interworking architecture between a smart TV and a smart phone. This architecture provides control mechanism for the newly adopted App on Smart-TV with smart phone. The general method connecting between a smart phone and a mobile AP is very carefully complex and troublesome procedure. The mobile AP transfers data from a smart phone to a smart TV after getting the connection. Connecting procedure between a smart phone and a mobile AP is therefore necessary operation. We worked out the new procedure and control method that acquires some information from Near Field Communication or Quick Reference codes for connecting between a smart TV and a smart phone. Our proposed architecture was confirmed practical possibility as user-oriented automatic connection and simple manipulation for control a kiosk or various display equipment.

• Journal of Internet Computing and Services
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• v.19 no.3
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• pp.35-42
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• 2018

Deep learning is known as a method of high accuracy among several methods for image classification. In this paper, we propose a method of enhancing the accuracy of image classification using CNN with a batch normalization method for classification of images using deep CNN (Convolutional Neural Network). In this paper, we propose a method to add a batch normalization layer to existing neural networks to enhance the accuracy of image classification. Batch normalization is a method to calculate and move the average and variance of each batch for reducing the deflection in each layer. In order to prove the superiority of the proposed method, Accuracy and mAP are measured by image classification experiments using five image data sets SHREC13, MNIST, SVHN, CIFAR-10, and CIFAR-100. Experimental results showed that the CNN with batch normalization is better classification accuracy and mAP rather than using the conventional CNN.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.65-81
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• 1997

For the purpose of evaluating the appropriateness of AP-PCR as a facile, rapid and reproducible method for genotyping Streptococcus mutans, and selecting the discriminant primer for it, a DNA fingerprinting was performed on the microorganisms isolated from caries-free children and children with rampant caries, respectively. In the course of selecting appropriate primer for S. mutans genotyping, we chose S2 primer from 6 different primers which shows highest resolution on the agarose gel as well. Nineteen kinds of fingerprint patterns were observed in caries-free children and children with rampant caries which were produced by combination of 7 different fragments. Interestingly, the number of types observed in caries-free children was greater than that in children with rampant caries. And we observed Type 2 was predominant in children with rampant caries (about 80%) and relatively even distribution of each types in caries-free children. Furthermore, it was appeared that the major types in normal control were not or rarely found in children with rampant caries. In conclusion, we could establish simple, rapid and highly reproducible AP-PCR method for genotyping S. mutans. We also found differences in distribution of S. mutans between normal and patient, which suggested that cariogenicity is also dependent on qualitative aspects which is caused by the difference in genotypes of S. mutans in oral cavity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.122-124
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• 2010

WPS(Wifi Positioning System) is a location determination technique that utilizes AP information scattered all over the real world. In general, the finger print technique is used for location calculations in WPS. However the finger print technique is a location determination technique that utilizes average values and has problems in the accuracy of the location determination. It also shows low performance of the system due to arithmetic operations. In this paper, the MSS(Max Signal Strength) method is proposed to resolve the existing problems in the finger print technique. The proposed method can reduce the operation time and improve the accuracy of the system under the same conditions. Test environments of the system is presented and the performance of the system is analyzed to verify the methods.

• Journal of Ocean Engineering and Technology
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• v.24 no.2
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• pp.74-81
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• 2010

Ship STEP is the international standard for the exchange of ship modeling data between heterogeneous systems. It is expected that STEP AP218 can be used for seamless data exchange between various CAD/CAM/CAE systems used in the shipbuilding design process. Although the conformance assessment for standards would maximize the performance and confidence about data exchanges, most research has been directed toward interoperability testing. ISO SC4/TC184 only provides the method for conformance testing, and it can be used with test cases on application protocols. Even though standards have been defined for conformance assessment and testing, there is no organization or association. CAD vendors have focused on interoperability testing for evaluation of the performance of their systems. In this paper, the conformance testing criteria for AP218 have been developed with abstract test cases of ship structures. The requested STEP translator was also reviewed with a developed item pool of testing criteria. The criteria methodology would be a guideline for the development of translators and interfaces. The item pool method of testing criteria for conformance assessment would increase performance and efficiency of data translators for Ship STEP and other standards.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.146-151
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• 2013

With the development of mobile internet, requirements of positioning accuracy for the LBS (Location Based Service) are becoming more and more higher. The LBS is based on the position of each mobile device. So, it requires a proper acquisition of accurate user's indoor position. Thus indoor positioning technology and its accuracy is crucial for various LBS. In general, RSSI (Received Signal Strength Indicator) measurements are used to obtain the position information of mobile unit under WLAN environment. However, indoor positioning error increases as multiple AP's configurations are becoming more complex. To overcome this problem, an enhanced indoor localization method by AP (Access Point) selection criteria adopting DOP (Dilution of Precision) is proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1259-1265
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• 2013

In wireless environment such as wireless LAN, proper location of wireless LAN AP allows us to take an effective coverage to provide good wireless communication service. To simulate wireless environment, FDTD formulation is introduced and Gaussian pulse injection in grid space is considered to be replaced wireless LAN AP. So structural effect corresponding to location of arbitrary obstacle must be considered, and its received gain is estimated. An obstacle in scattering field should be modeled to be conductor and concrete wall and its diffraction effect for some cross wall is evaluated between transmitter and receiver point.

• Biomedical Science Letters
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• v.10 no.4
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• pp.473-477
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• 2004

Methicillin-Resistant Staphylococcus aureus (MRSA) strains are resistant to a wide range of antibiotics and are a major cause of nosocomial infections. Accurate and rapid typing of MRSA is needed to implement effective infection control measures. Arbitrarily Primed PCR (AP-PCR) is a very useful method in rapid typing. AP-PCR is not necessary information about target DNA sequence because this is basically DNA amplification and could be useful in epidemiological typing by classified band pattern. In this study, MRSA were isolated and identified from ICU, Neu, IM and Ped environments and investigated molecular typing by AP-PCR. Ped, the MRSA pattern determines the la, IIa type, 1M is Ib type, Neu is IIa type and ICU determines the IIa, lIb types. All MRSA in this study were typeable by AP-PCR, which was easy to perform and reproduce with evidence of MRSA for purposes of nosocomial infection control.