• International journal of advanced smart convergence
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• v.4 no.2
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• pp.14-19
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• 2015

Recently, water sewage disposal facilities are able to manage real-time data collection and record management through compact broadband modem LAN switching technology. Therefore, it needs more stable and efficient facility management. So, we required practical use of environmental facilities convergence based on broadband integrated modem. In this paper, we proposed short distance wireless communication network of compact broadband modem for sewage disposal facilities. And it received data inside of water treatment facility using the two communication methods (IEEE802.11x and IEEE802.15.4x). Then, our proposed an data-flow control algorithm of wireless network technology will prioritize processing data when emergency happen through collecting data, analysis data and processing. Lastly, we proved usefulness by experiment and simulation analysis.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.296-301
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• 2006

Even though the emergency telecommunication make possible that specialist offers medical care over emergency cases in moving vehicle, we still have many problems in transmitting the image or video of patient over several wireless networks. To alleviate the effect of channel errors on compressed video bit-stream, this paper analyzed the error resilient features of JPEG2000 standard and measured the quality of transmission over noisy wireless channel, CDMA2000 1xEV-DO networks, compared to the features of error resilient tool of MPEG-4. We also proposed the optimum solution of transmitting images over real 3G network using JPEG2000 error resilient tool.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.136-138
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• 2003

인터넷은 이미 대중화되어 있으며, 이러한 인터넷 망을 기초로 한 All-IP 망으로의 망 진화에 대한 논의가 활발하게 진행되고 있다. 또한 현재 상용중인 IPv4에 이동성을 부여한 이동 인터넷(Mobile IPv4)에 대한 연구는 IETF(Internet Engineering Task Force)를 중심으로 활발하게 진행 중에 있으며, 이에 대한 구현 및 개발은 이미 많은 연구단체에서 많은 성과를 보여주고 있다. 본 논문에서는 3세대 이동통신 모델 중의 하나인 CDMA2000 1x 환경에서 기 구현된 Wire-less LAN에서의 이동 인터넷(Mobile IPv4)을 연동하여, 이기종 망(Heterogeneous Network)에서의 이동 인터넷(Mobile Ipv4) 모델을 제시한다. 제시된 이동 인터넷(Mobile IPv4) 프로토콜은 Layer-2망으로서 Wireless LAN과 CDMA2000 1x을 모두 사용하며, 하부 망(Layer-2 Network)의 변화에 능동적으로 반응하여, 통신을 유지한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.9
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• pp.828-837
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• 1991

본 논문에서는 CCITT에서 채택된 X.2.5 network과 IBM이 채택한 System network architecture(SNA)의 synchronous data link control(SDLC)간의 protocol converter의 성능 분석을 한다. 여기서 protocol converter의 link level map-ping method를 사용하여 구현 되었다고 가정한다. 성능 분석을 통하여 각종 parameter에 대한 throughput과 mean waiting time을 구하며, 다양한 paramerter에 대하여 최적의 값을 조사한다. 특히 converter가 추정한 SDLC frame이 X.25. network packetizing과 규정한 최대 data packet size 보다 더 클 경우에 frame을 분할하게 되는데. 분할방식에 있어서 full and remainder packetzing과 equal packetizing 도입하여 서로간의 성능을 비교한다. message를 분할 할 때 조격으로 나누는 것이 frame의 오류를 줄일 수 있기 때문에 전자보다 후자가 성능면에서 우수함을 알 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.681-683
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• 2023

폐암은 전 세계적으로 사망률이 가장 높은 암 질환으로, 조기 발견 및 신속한 치료를 위해서는 흉부 X-ray 영상 내 악성 결절을 놓치지 않는 것이 중요하다. 그러나 흉부 X-ray 영상은 정밀도의 한계로 진단 결과에 대한 신뢰도가 낮아, 이를 보조하는 도구의 개발이 요구된다. 기존의 폐암 진단 보조 도구는 학습 기반의 기법으로, 진단 결과에 대한 설명성(explainability)이 없다는 위험성을 갖는다. 이에 본 논문에서는 통계 분석에 기반한 결절의 석회화 여부 진단 기법을 제안한다. 제안하는 기법은 결절과 해부학적 구조물의 밝기 차 분포로부터 석회화 여부를 판단하며, 그 결과 민감도 65.22%, 특이도 88.48%, 정확도 83.41%의 성능을 보였다.

• International Journal of Contents
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• v.2 no.4
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• pp.12-18
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• 2006

The number of wireless public network user is increasing rapidly. Security problem for user authentication has been increased on existing wireless network such as IEEE802.11 based Wireless LAN. As a solution, IEEE802.1x (EAP-MD5, EAP-TLS, EAP-TTLS), X.509, protocol or security system was suggested as a new disposal plan on this problem. In this study, we overview main problem on existing EAP-MD5 authentication mechanism on Wireless LAN and propose a SMS(Short Message Service) based secure authentication and accounting mechanism for providing security enhanced wireless network transactions.

• International Journal of Control, Automation, and Systems
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• v.2 no.1
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• pp.92-99
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• 2004

In this paper, the decoupled neural network reference compensation technique (DRCT) is applied to the control of a two degrees-of-freedom inverted pendulum mounted on an x-y table. Neural networks are used as auxiliary controllers for both the x axis and y axis of the PD controlled inverted pendulum. The DRCT method known to compensate for uncertainties at the trajectory level is used to control both the angle of a pendulum and the position of a cart simultaneously. Implementation of an on-line neural network learning algorithm has been implemented on the DSP board of the dSpace DSP system. Experimental studies have shown successful balancing of a pendulum on an x-y plane and good position control under external disturbances as well.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.3
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• pp.130-138
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• 1995

In this paper, a Novel Approach is Proposed which Identifies linear system Parameters Using a multilayer feedforward neural network trained with backpropagation algorithm. The parameters of linear system can be represented by x9t)/x(t) and x(t)/u(t). Thud, its parameters can be represented in terms of the derivative of output with respect to input of parameters can be represented in terms of the derivative of output with respect to input of trained neural network which is a function of weights and output of neurons. Mathematical representation of the proposed approach is derived, and its validity is shown by simulation results on 2-layer and 3-layer neural network.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.509-520
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• 2009

The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.613-620
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• 2021

The purpose of this study is to propose a convolutional neural network model that can classify normal and abnormal(cardiomegaly) in chest X-ray images. The training data and test data used in this paper were used by acquiring chest X-ray images of patients diagnosed with normal and abnormal(cardiomegaly). Using the proposed deep learning model, we classified normal and abnormal(cardiomegaly) images and verified the classification performance. When using the proposed model, the classification accuracy of normal and abnormal(cardiomegaly) was 99.88%. Validation of classification performance using normal images as test data showed 95%, 100%, 90%, and 96% in accuracy, precision, recall, and F1 score. Validation of classification performance using abnormal(cardiomegaly) images as test data showed 95%, 92%, 100%, and 96% in accuracy, precision, recall, and F1 score. Our classification results show that the proposed convolutional neural network model shows very good performance in feature extraction and classification of chest X-ray images. The convolutional neural network model proposed in this paper is expected to show useful results for disease classification of chest X-ray images, and further study of CNN models are needed focusing on the features of medical images.