• Title, Summary, Keyword: Filtering

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Development of an evaluation method for nuclear fuel debris-filtering performance

  • Park, Joon-Kyoo;Lee, Seong-Ki;Kim, Jae-Hoon
    • Nuclear Engineering and Technology
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    • v.50 no.5
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    • pp.738-744
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    • 2018
  • Fuel failure due to debris is a major cause of failure in pressurized water reactors. Fuel vendors have developed various filtering devices to reduce debris-induced failure and have evaluated filtering performance with their own test facilities and methods. Because of the different test facilities and methods, it is difficult to compare filtering performances objectively. This study presents an improved filtering test and an efficiency calculation method to fairly compare fuel-filtering efficiency regardless of the vendor's filtering features. To enhance the reliability of our evaluation, we established requirements for the test method and had a facility constructed according to the requirements. This article describes the debris specimens, the amount of debris, and the replicates for the proposed test method. A calculation method of comprehensive debris-filtering efficiency using a weighted mean is proposed. The test method was verified by repeated tests, and the tests were carried out using the PLUS7 and 17ACE7 test fuels to calculate the comprehensive debris-filtering efficiencies. The evaluation results revealed that the filtering performance of PLUS7 is better than that of 17ACE7. The proposed method can be used on any kind of debris-filtering devices and is appropriate for use as a standard.

A New Approach Combining Content-based Filtering and Collaborative Filtering for Recommender Systems (추천시스템을 위한 내용기반 필터링과 협력필터링의 새로운 결합 기법)

  • Kim, Byeong-Man;Li, Qing;Kim, Si-Gwan;Lim, En-Ki;Kim, Ju-Yeon
    • Journal of KIISE:Software and Applications
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    • v.31 no.3
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    • pp.332-342
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    • 2004
  • With the explosive growth of information in our real life, information filtering is quickly becoming a popular technique for reducing information overload. Information filtering technique is divided into two categories: content-based filtering and collaborative filtering (or social filtering). Content-based filtering selects the information based on contents; while collaborative filtering combines the opinions of other persons to make a prediction for the target user. In this paper, we describe a new filtering approach that seamlessly combines content-based filtering and collaborative filtering to take advantages from both of them, where a technique using user profiles efficiently on the collaborative filtering framework is introduced to predict a user's preference. The proposed approach is experimentally evaluated and compared to conventional filtering. Our experiments showed that the proposed approach not only achieved significant improvement in prediction quality, but also dealt with new users well.

Nonlinear Anisotropic Filtering with Considering of Various Structures in Magnetic Resonance Imaging (자기공명영상에서 다양한 구조들을 고려한 비선형 이방성 필터링)

  • Song Young-Chul
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.3
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    • pp.148-155
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    • 2003
  • In this paper, a nonlinear anisotropic filtering method without the loss of important information happened due to the repeated filtering in magnetic resonance images is proposed. First of all original images are divided into four regions, e.g., SPR(Strong Plain Region), EPR(Easy Plain Region), SER(Strong Edge Region), and EER(Easy Edge Region). An optimal template among multiple templates is selected, then the nonlinear anisotropic filtering based on the template is applied in pixel by pixel basis. In the proposed algorithm, filtering strength of EER containing important information is adjusted very weak and filtering strength for remaining regions is also adjusted according to the degree of the importance. In spite of repeated filtering, resulting images by the proposed method could still preserve anatomy information of original images without any degradation. Compared to the existing nonlinear anisotropic filtering, the proposed filtering method with multiple templates provides higher reliability for filtered images.

Semantic-Based Web Information Filtering Using WordNet (어휘사전 워드넷을 활용한 의미기반 웹 정보필터링)

  • Byeon, Yeong-Tae;Hwang, Sang-Gyu;O, Gyeong-Muk
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.11S
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    • pp.3399-3409
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    • 1999
  • Information filtering for internet search, in which new information retrieval environment is given, is different from traditional methods such as bibliography information filtering, news-group and E-mail filtering. Therefore, we cannot expect high performance from the traditional information filtering models when they are applied to the new environment. To solve this problem, we inspect the characteristics of the new filtering environment, and propose a semantic-based filtering model which includes a new filtering method using WordNet. For extracting keywords from documents, this model uses the SDCC(Semantic Distance for Common Category) algorithm instead of the TF/IDF method usually used by traditional methods. The world sense ambiguation problem, which is one of causes dropping efficiency of internet search, is solved by this method. The semantic-based filtering model can filter web pages selectively with considering a user level and we show in this paper that it is more convenient for users to search information in internet by the proposed method than by traditional filtering methods.

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Study on Performance Improvement of Video in the H.264 Codec (H.264 코덱에서 동영상 성능개선 연구)

  • Bong, Jeong-Sik;Jeon, Joon-Hyeon
    • Proceedings of the KIEE Conference
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    • pp.532-535
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    • 2005
  • These days, many image processing techniques have been studied for effective image compression. Among those, 2D image filtering is widely used for 2D image processing. The 2D image filtering can be implemented by performing ID linear filtering separately in the direction of horizontal and vertical. Efficiency of image compression depends on what filtering method is used. Generally, circular convolution is widely used in the 2D image filtering for image processing. However it doesn't consider correlations at the region of image boundary, therefore filtering can not be performed effectively. To solve this problem. I proposed new convolution technique using Symmetric-Mirroring convolution, satisfying the 'alias-free' and 'error-free' requirement in the reconstructed image. This method could provide more effective performance than former compression methods. Because it used very high correlative data when performed at the boundary region. In this paper, pre-processing filtering in H.264 codec was adopted to analyze efficiency of proposed filtering technique, and the simulator developed by Matlab language was used to examine the performance of the proposed method.

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Design of RFID Air Protocol Filtering and Probabilistic Simulation of Identification Procedure (RFID 무선 프로토콜 필터링의 설계와 확률적 인식 과정 시뮬레이션)

  • Park, Hyun-Sung;Kim, Jong-Deok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.6B
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    • pp.585-594
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    • 2009
  • Efficient filtering is an important factor in RFID system performance. Because of huge volume of tag data in future ubiquitous environment, if RFID readers transmit tag data without filtering to upper-layer applications, which results in a significant system performance degradation. In this paper, we provide an efficient filtering technique which operates on RFID air protocol. RFID air protocol filtering between tags and a reader has some advantages over filtering in readers and middleware, because air protocol filtering reduces the volume of filtering work before readers and middleware start filtering. Exploiting the air protocol filtering advantage, we introduce a geometrical algorithm for generating air protocol filters and verify their performance through simulation with analytical time models. Results of dense RFID reader environment show that air protocol filtering algorithms reduce almost a half of the total filtering time when compared to the results of linear search.

DCT Domain Separable Symmetric 2-D Linear Filtering (DCT 영역에서의 2차원 분리 대칭 선형 필터링)

  • 임창훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5C
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    • pp.461-467
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    • 2003
  • We propose an efficient method for separable symmetric linear filtering in the DCT domain. First, separable 2-D linear filtering is decomposed into the cascade of 1-D filtering in the DCT domain. We investigate special characteristics of DCT domain filtering matrices when the filter coefficients are symmetric. Then we present the DCT domain 2-D filtering method using these characteristics. The proposed method requires smaller number of multiplications including typical sparseness of DCT coefficients compared to previous DCT domain linear filtering methods. Also, the proposed method is composed of simple and regular operations, which would be appropriate for efficient VLSI implementation.

Image Sequence Stabilization Scheme Using FIR Filtering

  • Kim, Pyung-Soo
    • International Journal of Control, Automation, and Systems
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    • v.1 no.4
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    • pp.515-519
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    • 2003
  • This paper proposes a new image sequence stabilization (ISS) scheme based on filtering of absolute frame positions. The proposed ISS scheme removes undesired motion effects in real-time, while preserving desired gross camera displacements. The well-known finite impulse response (FIR) filter is adopted for filtering. The proposed ISS scheme provides a filtered position and velocity with fine inherent properties. It is demonstrated that the filtered position is not affected by the constant velocity. It is also shown that the filtered velocity is separated from the position. Via numerical simulations, the performance of the proposed scheme is shown to be superior to the existing Kalman filtering scheme.

An Extended Service Filtering Technique for Mass Calling-Type Services Using Intelligent Peripheral in an SCP-Bound Network

  • Jeong, Kwang-Jae;Kim, Tae-Il;Choi, Go-Bong
    • ETRI Journal
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    • v.20 no.2
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    • pp.115-132
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    • 1998
  • This paper proposes an extended service filtering technique to prevent overload in service control point (SCP) due to televoting (VOT) or mass calling (MAS) services with the heavy traffic characteristics. Also, this paper compares this extended technique with the existing overload control techniques, and calculates steady state call blocking probabilities in intelligent network (IN) under overload conditions. The proposed technique considers SCP overload and IN Capability Set (CS)-1 services (such as VOT or MAS service) that have to use the specialized resources of intelligent peripheral (IP). This technique uses first an activating step in which SCP requests service filtering to service switching point (SSP). Then, in the filtering step, SSP sends filtering results to SCP periodically or each N-calls. Also, when filtering time-out expires, SSP stops service filtering, and sends service filtering response to SCP in the deactivating step. This paper applies this technique to VOT/MAS service, and calculates SCP and SSP-IP (circuit) call blocking probabilities by using an analytical VOT/MAS service model. With the modeling and analyzing of this new technique, it shows that this technique reduces the traffic flow into SCP from SSP and IP prominently.

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A Study on the Contour-Preserving Image Filtering for Noise Removal (잡음 제거를 위한 윤곽선 보존 기법에 관한 연구)

  • Yoo, Choong-Woong;Ryu, Dae-Hyun;Bae, Kang-Yeul
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.4
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    • pp.24-29
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    • 1999
  • In this paper, a simple contour-preserving filtering algorithm is proposed. The goal of the contour-preserving filtering method is to remove noise ad granularity as the preprocessing for the image segmentation procedure. Our method finds edge map and separates the image into the edge region and the non-edge region using this edge map. For the non-edge region, typical smoothing filters could be used to remove the noise and the small areas during the segmentation procedure. The result of simulation shows that our method is slightly better than the typical methods such as the median filtering and gradient inverse weighted filtering in the point of view of analysis of variance (ANOVA).

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