• Title/Summary/Keyword: 공학적 문제해결

Search Result 2,121, Processing Time 0.029 seconds

Personalized Document Snippet Extraction Method using Fuzzy Association and Pseudo Relevance Feedback (의사연관 피드백과 퍼지 연관을 이용한 개인화 문서 스니핏 추출 방법)

  • Park, Seon;Jo, Gwang-Mun;Yang, Hu-Yeol;Lee, Seong-Ro
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.49 no.2
    • /
    • pp.137-142
    • /
    • 2012
  • Snippet is a summaries information of representing web pages which search engine provides user. Snippet and page rank in search engine abundantly influence user for visiting web pages. User sometime visits the wrong page with respect to user intention when uses snippet. The snippet extraction method is difficult to accurate comprehending user intention. In order to solve above problem, this paper proposes a new snippet extraction method using fuzzy association and pseudo relevance feedback. The proposed method uses pseudo relevance feedback to expand the use's query. It uses the fuzzy association between the expanded query and the web pages to extract snippet to be well reflected semantic user's intention. The experimental results demonstrate that the proposed method can achieve better snippet extraction performance than the other methods.

Error Concealment Method Based on POCS for Multi-layered Video Coding (다계층 비디오 코딩에 적용 가능한 POCS 기반 에러 은닉 기법)

  • Yun, Byoung-Ju
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.46 no.4
    • /
    • pp.67-75
    • /
    • 2009
  • Multi-layered video coding that provides scalability across the visual content has emerged for easily adaptive service over current heterogeneous network. However, the network is still error prone environment so that video service may suffer packet loss or erroneous decoding of the video. Especially distortion caused by the burst error may propagate to several pictures until intra refreshing, which will raise a terrific degradation of picture quality. To overcome the problem at terminal independently, we propose a new error concealment algorithm for the multi-layered video coding. The proposed method uses the similarity of between layers in the multi-layered video coding and POCS (Projections Onto Convex Sets) which is a powerful error concealment tool, but heavily dependent on initial values. To find adequate initial value which can reduce iteration times as well as achieve high performance, we took consideration into both features of layered approach coding and the correlation in neighbor blocks. The simulation results show that the proposed concealment method works well.

Adaptive Feedback Interference Cancellation Using Correlations for WCDMA Wireless Repeaters (WCDMA용 무선중계기에서 상관도를 이용한 적응적 궤환 간섭 제거)

  • Moon, Woo-Sik;Im, Sung-Bin;Kim, Chong-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.44 no.7 s.361
    • /
    • pp.35-40
    • /
    • 2007
  • As the mobile communication service is widely used and the demand for wireless repeaters is rapidly increasing because of the easiness of extending service areas. But a wireless repeater has a problem that the output of the transmit antenna is partially fed back to the receive antenna, which results in feedback interference. In this paper, we propose a new varable step-size LMS algorithm which utilizes correlation between reference and error signals to adjust the step sizes, for cancelling the feedback interference signals in the WCDMA repeater under time-varying multi-path channels. The proposed algorithm was evaluated through computer simualation by being applied to the feedback canceling filter of the WCDMA repeater. The simulation results demonstrated that the proposed one is superior to the conventional ones in terms of the cancelation perormance.

An Average Shape Model for Segmenting Prostate Boundary of TRUS Prostate Image (초음파 전립선 영상에서 전립선 경계 분할을 위한 평균 형상 모델)

  • Kim, Sang Bog;Chung, Joo Young;Seo, Yeong Geon
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.3 no.5
    • /
    • pp.187-194
    • /
    • 2014
  • Prostate cancer is a malignant tumor occurring in the prostate. Recently, the repetition rate is increasing. Image inspection method which we can check the prostate structure the most correctly is MRI(Magnetic Resonance Imaging), but it is hard to apply it to all the patients because of the cost. So, they use mostly TRUS(Transrectal Ultrasound) images acquired from prostate ultrasound inspection and which are cheap and easy to inspect the prostate in the process of treating and diagnosing the prostate cancer. Traditionally, in the hospital the doctors saw the TRUS images by their eyes and manually segmented the boundary between the prostate and nonprostate. But the manually segmenting process not only needed too much time but also had different boundaries according to the doctor. To cope the problems, some automatic segmentations of the prostate have been studied to generate the constant segmentation results and get the belief from patients. In this study, we propose an average shape model to segment the prostate boundary in TRUS prostate image. The method has 3 steps. First, it finds the probe using edge distribution. Next, it finds two straight lines connected with the probe. Finally it puts the shape model to the image using the position of the probe and straight lines.

Integral C-V Converter for a Fully Differential Capacitive Pressure Sensor (완전차동용량형 압력센서를 위한 적분형 C-V 변환기)

  • Lee, Dae-Sung;Kim, Kyu-Chull;Park, Hyo-Derk
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.39 no.9
    • /
    • pp.62-71
    • /
    • 2002
  • An intergral C-V converter is proposed to solve the nonlinearity problem of capacitive pressure sensors. The integral C-V converter consists of a switched-capacitor integrator and a switched-capacitor differential amplifier. It converts the sensor capacitance change which is inversely proportional to an applied pressure into a linear voltage output. Various PSPICE simulations prove that the convertor has excellent characteristics, such as low nonlinearity less than 0.01%/FS and low sensitivity to parallel offset capacitance and parasitic capacitance for the displacement range of sensor diaphragm set to 0 ${\sim}$ 90% of the initial distance between the electrodes in the simulation. We also show that the offset compensation and the gain trimming are easily achieved with the integral C-V converter.

A Built-in Self-Test of Static Parameters for Analog-to-Digital Converters (아날로그-디지털 변환기의 정적 파라미터 테스트를 위한 내장 자체 테스트 방법)

  • Kim, In-Cheol;Jang, Jae-Won;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.49 no.5
    • /
    • pp.30-36
    • /
    • 2012
  • A new BIST(Built-In Self-Test) scheme to test ADC(Analog-to-Digital Converter) with a transition detector is proposed. The proposed BIST is able to replaces histogram method, the most popular approach in static testing of ADC. With a ramp signal as an input test stimulus, the proposed BIST calculates ADC's static parameters such as offset, gain, INL(Integral Non-Linearity) and DNL(Differential Non-Linearity). The three detectors in the proposed BIST can deal with a transient zone problem, a phenomenon due to random noise in real test environments and are cost efficient at various acceptable ranges determined as a test spec. The simulation results validate that our method performs accurate static test and show the reduction of the hardware overhead.

Model Parameter-based Rate Control Algorithm for Constant Quality Real-Time Video Coding (실시간 부호화를 위한 모델 파라미터 기반 일정 화질 비트율 제어 기법)

  • Jeong, Jin-Woo;Cho, Kyung-Min;Choe, Yoon-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.45 no.3
    • /
    • pp.93-102
    • /
    • 2008
  • In this paper, we propose a rate control algorithm for constant quality real time video coding. To achieve constant quality, previous algorithm exploit mean absolute of difference(MAD) as measure of frame complexity. However, if scene is abruptly changed or if quantization parameter is not constant, encoder produces various output bits with same MAD. Therefore we know that MAD does not appropriately reflect characteristic of frame. To solve this problem, we exploit model parameter as measure of frame complexity. Because model parameter means slope between output bits and MAD, it reflects correctly complexity of frame. And because previous model, R-MAD model, is not considered quantization parameter, as quantization parameter increases or decreases, model parameter of frame also vary. So model parameter obtained using previous model cannot reflect internal characteristic of video. We solve this problem using proposed model, which is considered quantization parameter. Experiment results show that our algorithm provide better performance, in terms of quality smoothness than previous algorithm. Especially, when scene is abruptly changed, our algorithm alleviates quality drop.

The Development of Tunnel Behavior Prediction System Using Artificial Neural Network (인공신경망을 이용한 터널 거동 예측 시스템 개발)

  • 이종구;문홍득;백영식
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.2
    • /
    • pp.267-278
    • /
    • 2003
  • Artificial neural networks are efficient computing techniques that are widely used to solve complex problems in many fields. In this study, in order to predict tunnel-induced ground movements, Tunnel Behavior Prediction System (TBPS) was developed by using these artificial neural networks model, based on a Held instrumentation database (i.e. crown settlement, convergence, axial force of rock bolt, compressive and shear stress of shotcrete, stress of concrete lining etc.) obtained from 193 location data of 31 different tunnel sites where works are completed. The study and test of the network were performed by Back Propagation Algorithm which is known as a systematic technique for studying the multi-layer artificial neural network. The tunnel behaviors predicted by TBPS were compared with monitored data in the tunnel sites and numerical analysis results. This study showed that the values obtained from TBPS were within allowable limits. It is concluded that this system can effectively estimate the tunnel ground movements and can also be used f3r tunneling feasibility study, and basic and detailed design and construction of tunnel.

Delay Compensation Mechanism for a Link Failure in Control Networks of Railway Vehicles (철도 차량을 위한 제어용 통신망에서 링크 장애 시 딜레이 보상 기법)

  • Hwang, Hwanwoong;Kim, Sanghyun;Yun, Ji-Hoon
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.2
    • /
    • pp.10-16
    • /
    • 2016
  • For higher reliability against a link failure of a control network in railway vehicles, a recovery mechanism is needed. We introduce a problem that, when a link failure occurs in a ring-topology control network, a node may experience a significant increase of transmission delay depending on its relative position within the network. We then propose two mechanisms to solve this problem: (1) differentiating and prioritizing node traffic in forwarding; and (2) switching some nodes to a backup bus-topology network. Our simulation study shows that, while the first mechanism achieves a limited gain by only compensating queuing delay, the second one gets a sufficient gain which is impacted by the number of nodes switched to the bus network.

Wireless Sensor Network for Wildfire Monitoring (산불 감시를 위한 무선 센서네트워크)

  • Sohn, Jung-Man;Seok, Chang-Ho;Park, Whang-Jong;Chang, Yu-Sik;Kim, Jin-Chun
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.11 no.4
    • /
    • pp.846-851
    • /
    • 2007
  • The wireless sensor network is one of the most practical and cost-effective solutions for monitoring systems covering wild and wide area such as wildfire monitoring. However, the RF distance between sensor nodes is very short due to the need of low power consumption of the sensor node, so the number of sensor nodes to be deployed in the target area is more than tens of thousands. In this paper, we design and analyze the deployment issues as well as re-deployment problem occurred when the battery is exhausted. We also propose the needs and solutions for coverage problem in dynamic deployment. By the experimental evaluations, we analyze the packet success ratio between sensor nodes under various environments such as obstacles and variable distances.