• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1493-1501
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• 1999

For the multimedia conference in various networks, international standard works make progress with H and T series. T.120 series are recommended for multipoint data conference in various networks, but its demerit is not supported with video and audio capabilities. H.32X series are recommended for videoconference in various networks. To solve these problems, the combination of H.32X and T.120 are used. But many difficulties exist for consistent control. To solve these problems, T.130, T.131 and T.132 standardizations are made progress, and these are analyzed and implemented over LAN(Local Area Network). Our system introduced in this paper is currently operated on LAN, but can be operated with mixed networks with addition of underlying network dependent protocols.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.667-669
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• 2002

IEEE 802.1x는 LAN(Local Area network) 환경에서의 인증을 위해서 IEEE에서 제안한 인증 표준 프로토콜이다 IEEE 802.1x는 token ring, FDDI(Fiber Distributed-Data Interrace), 802.3 등 다양한 802 표준에서 동작할 수 있도록 고안되었다 802.1x는 supplicant와 Authenticator, Authentication Server로 구성된다. 이러한 802.1x의 LAN 환경에서 QoS(Quality of Service)를 보장하기 위해서는 자원 예약 메커니즘이 필요하다. 이러한 자원 예약 메커니즘으로는 RSVP(Resource Resonation Protocol)가 있는데 이것은 유선 네트워크를 위해 설계되었기 때문에 새롭게 수정이 불가피하다. 본 논문에서는 RSVP를 수정 보완하여 WLAN(Wireless LAN)에 맞는 시그널링 프로토콜을 제안한다. 제안한 시그널링 프로토콜을 이용하여 WLAN 에서의 QoS 문제를 해결한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.553-555
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• 2002

인증(Authentication)과 암호화 키(Key) 운용 방법론은 통신 서비스 고려시 소홀할 수 없는 중요한 문제이다. 현재 가장 널리 보급되어 사용중인 IEEE 802.11 기술에서도 이와 같은 보안 지원에 문제가 있음이 명백히 드러나고 있다. 포트 컨트롤을 통하여 접속 지점에서부터 통신을 제어하는 IEEE 802.1X는 이를 위한 적절한 보안 해결책이 되고 있고, IEEE 802.11 WGi는 802.1X를 기초로 하는 RSN(Robust Security Network)울 위한 표준화가 진행중이다. 그러나 IEEE 802.1X 프레임워크에서 상호 인증과, 키 분배 및 갱신 정책은 채택하는 인증 프로토콜에 강하게 의존하는 약점을 가지고 있다. 따라서 본 논문에서는 UMTS 보안 아키텍처의 인증 토큰(Authentication Token)을 추가하여 IEEE 802.1X 프레임워크에 상호 인증 및 키 갱신 구조를 포함하도록 하였다.

• Journal of Digital Contents Society
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• v.6 no.3
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• pp.143-147
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• 2005

In this paper, we developed X-internet framework based on Flash and API for this framework. Proposed X-internet framework based on Flash enables to obtain design with dynamic user interface compare to web application and enables to reduce development time. Since this framework use the API that we developed in this study art flash player, this framework does not need server module. In analytical results, it has been shown that proposed x-internet framework have efficient characteristics such as network traffic, low development cost and dynamic user interface implementation. Since this X-internet framework can operate in environment of current developer friendly, it is useful for development of various new application programs.

• Journal of the Korean Wood Science and Technology
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• v.46 no.5
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• pp.597-609
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• 2018

Korea Forest Service has supplied 76 industrial wood pellet boilers from 2011 to 2015 through subsidy programs. Since carbon monoxide (CO) and nitrogen oxides ($NO_x$) generated during boiler combustion are substances that lead to death in the case of acute poisoning, it is very important to reduce emissions. Therefore, the CO and $NO_x$ emission values of 63 boilers excluding the hot air blower and some boilers initially supplied were analyzed. The emission factor was also calculated from the measured exhaust gas concentration (based on exhaust gas $O_2$ concentration of 12%). The average value of CO emitted from industrial wood pellet boilers was 49 ppm and it was confirmed that the CO concentration was decreasing as the years passed. The emission factor of CO was 0.73 g/kg. The average value of $NO_x$ emitted from industrial wood pellet boilers was 67 ppm and the emission factor of $NO_x$ was 1.63 g/kg. Unlike CO, there was no tendency to decrease according to the installation year. Both CO and $NO_x$ measurements met the limits of the Ministry of Environment. These $NO_x$ emission factors were compared with the $NO_x$ emission factors produced by certified low $NO_x$ burners. The $NO_x$ emission factor of industrial wood pellet boilers was about 1.9 times that of certified low $NO_x$ LNG combustors and about 0.92 times that of coal combustion.

• 한국정보통신설비학회:학술대회논문집
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• 2002.11a
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• pp.147-163
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• 2002

• Journal of the Korean Geotechnical Society
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• v.32 no.1
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• pp.55-62
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• 2016

This study presents the numerical results of soil-water characteristic curve for sandy soil by pore network model. The Jumunjin sand is subjected to the high resolution 3D X-ray computed tomographic imaging and its pore structure is constructed by the web of pore body and pore channel. The channel radius, essential to the computation of capillary pressure, is obtained based on the skeletonization and Euclidean Distance transform. The experimentally obtained soil-water characteristic curve corroborates the numerically estimated one. The pore channel radius defined by minimum radii of pore throat results in the slightly overestimation of air entry value, while the overall evolution of capillary pressure resides in the acceptable range. The relative permeability computed by a series of suggested models runs above that obtained by pore network model at high degree of saturation.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1171-1177
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• 1999

The changes on microstucture of recombinated gels with different ratio of amylose(A) and amylopectin(AP) which were isolated from nonwaxy rice starch were investigated by scanning electron microscope(SEM) and X-ray diffractometer. As the concentration of amylose was above 3%(1.08% of soluble amylose) in the amylose suspension, gel matrix became like a three-dimensional network. The microstructure of amylose gels showed a network including macroporous structure, but the higher the ratio of amylopectin content were, the firmer network were formed. In case of A/AP mixed gels(15%) with different amylose/amylopectin percent ratios ; 0/5, 5/10, 10/5, 15/0%, as the storage time of gels and the percent ratio of amylose content were increased, network was formed harder with thick films. While X-ray diffractograms of waxy rice starch which contained 100% amylopectin showed A type, those of purified amylose and amylopectin showed V type and amorphous patterns, respectively. Amylose(3%) gels added $2{\sim}3%$ amylopectin and A/AP mixed gels(15%) showed peak at $2{\theta}\;=\;17.0^{\circ}$which were shown B type crystallinity similar af retrograded starches. Also as the percent ratio of amylose content in mixed gels was increased, peak intensity wat increased.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.211-215
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• 2015

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving. The intelligent vehicle network is comprised for the driving information offering changing rapidly of the communication(V2V: Vehicle to Vehicle) between the car and the car, communication(V2I : Vehicle to Infrastructure) between the infrastructure and the car, and V2X (Vehicle to Nomadic).

• Journal of Biomedical Engineering Research
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• v.42 no.4
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• pp.167-174
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• 2021

The purpose of this study is to classify TIFF images, PNG images, and JPEG images using deep learning, and to compare the accuracy by verifying the classification performance. The TIFF, PNG, and JPEG images converted from chest X-ray DICOM images were applied to five deep neural network models performed in image recognition and classification to compare classification performance. The data consisted of a total of 4,000 X-ray images, which were converted from DICOM images into 16-bit TIFF images and 8-bit PNG and JPEG images. The learning models are CNN models - VGG16, ResNet50, InceptionV3, DenseNet121, and EfficientNetB0. The accuracy of the five convolutional neural network models of TIFF images is 99.86%, 99.86%, 99.99%, 100%, and 99.89%. The accuracy of PNG images is 99.88%, 100%, 99.97%, 99.87%, and 100%. The accuracy of JPEG images is 100%, 100%, 99.96%, 99.89%, and 100%. Validation of classification performance using test data showed 100% in accuracy, precision, recall and F1 score. Our classification results show that when DICOM images are converted to TIFF, PNG, and JPEG images and learned through preprocessing, the learning works well in all formats. In medical imaging research using deep learning, the classification performance is not affected by converting DICOM images into any format.