• Title/Summary/Keyword: Noise Removal

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Design of Sensor Network for Estimation of the Shape of Flexible Endoscope (연성 대장내시경의 형상추정을 위한 센서네트워크의 설계)

  • Lee, Jae-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.299-306
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    • 2016
  • In this paper, a method of shape prediction of an endoscope handling robot that can imitate a surgeon's behavior using a sensor network is suggested. Unit sensors, which are composed of a 3-axis magnetometer and 3-axis accelerometer pair comprise the network through CAN bus communication. Each unit of the sensor is used to detect the angle of the points in the longitudinal direction of the robot, which is made from a flexible tube. The signals received from the sensor network were filtered using a low pass Butterworth filter. Here, a Butterworth filter was designed for noise removal. Finally, the Euler angles were extracted from the signals, in which the noise was filtered by the low path Butterworth filter. Using this Euler angle, the position of each sensor on the sensor network is estimated. The robot body was assumed to consist of links and joints. The position of each sensor can be assumed to be attached to the center of each link. The position of each link was determined using the Euler angle and kinematics equation. The interpolation was carried out between the positions of the sensors to be able to connect each point smoothly and obtain the final posture of the endoscope in operation. The experimental results showed that the shape of the colonoscope can be visualized using the Euler angles evaluated from the sensor network suggested and the shape of serial link estimated from the kinematics chain model.

Consumer's Behaviors on the Laundering of Baby's Clothing - Comparison of Washing Machine Types - (영.유아복 세탁에 관한 소비자 행동 연구 - 세탁기 유형별 비교 -)

  • Lee, Su-Yeon;Le, Jeong-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.8
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    • pp.1231-1239
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    • 2007
  • The purpose of this study was to investigate consumer's behaviors on the laundering of baby's clothing according to washing machine types. The subjects were 255 consumers with babies(0-2 years) in Korea. The data were collected with a self-administered questionnaire and analyzed by Chi-square test and multiple response analysis, and SPSS 12.0 statistics package was used. Consumers were separated into two groups according to washing machine types with general pulsator type and drum-type. Consumer's behaviors between general pulsator type group and drum-type group of washing machines were also examined. The results of this study were as follows. In the consumer satisfaction for washing machine, mostly drum-type group of consumers were satisfied with their washing machines. As the reasons of washing machine's dissatisfaction, noise, washing time and low washing efficiency were high in the pulsator type group, and washing time, noise and high price in the drum-type washing machine group. The consumers concerned about separation of clothing and laundering label while they washed laundry by washing machine. However, they didn't separate clothing because the small volume of laundry and a long washing time. The most interest and required thing of consumers was complete rinsing without any detergents used in washing as well as the removal of soils for baby's clothing regardless of two washing machine types. And they complained food soils like milk and mother's milk etc. were not completely removed by washing machine. As a whole the washing frequency of baby's laundry was once per a day and the rinsing also more than three times per a laundry. Most of the consumers used a private detergents for baby's clothing(detergents for baby's clothing only), and preferred to the high or boiled temperature washing as a desirable baby's laundering. There were significant differences between general pulsator type group and drum-type group of washing machines on the laundering of baby's clothing in this study.

Effect of Ground Roll Suppression Based on Karhunen-Loeve Transform (카루넨-루베 변환을 이용한 탄성파 그라운드 롤 억제 효과)

  • Jang, Seonghyung;Lee, Donghoon
    • Geophysics and Geophysical Exploration
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    • v.22 no.4
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    • pp.177-185
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    • 2019
  • Ground roll is a surface wave which is usually observed in the land seismic data. It is one of the typical coherent noise. During the reflection data processing, ground roll is removed because it is considered as noise. This removal process often causes the loss of reflection signals if the ground roll overlaps reflection signals. In this study, we look over Karhunen-Loeve Transform (KLT) and analyze its effects to suppress the ground roll appropriately while reducing the reflection loss. Numerical tests in homogeneous elastic media show that the ground roll has been properly rejected. However, the field data application reveals that there is no significant suppression of ground roll when compared to band-pass filtering. This can be considered that it is hard to calculate horizontally aligned gathers in the field data because the ground roll contains a wide range of frequency bands. On the contrary, the result of singular value decomposition (SVD) filtering shows that the ground roll has been significantly reduced. It is thought that the SVD filtering performs better in the ground roll suppression than KLT because it is easy to calculate the horizontally aligned gathers in the SVD filtering.

Development of a Reproducibility Index for cDNA Microarray Experiments

  • Kim, Byung-Soo;Rha, Sun-Young
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.05a
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    • pp.79-83
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    • 2002
  • Since its introduction in 1995 by Schena et al. cDNA microarrays have been established as a potential tool for high-throughput analysis which allows the global monitoring of expression levels for thousands of genes simultaneously. One of the characteristics of the cDNA microarray data is that there is inherent noise even after the removal of systematic effects in the experiment. Therefore, replication is crucial to the microarray experiment. The assessment of reproducibility among replicates, however, has drawn little attention. Reproducibility may be assessed with several different endpoints along the process of data reduction of the microarray data. We define the reproducibility to be the degree with which replicate arrays duplicate each other. The aim of this note is to develop a novel measure of reproducibility among replicates in the cDNA microarray experiment based on the unprocessed data. Suppose we have p genes and n replicates in a microarray experiment. We first develop a measure of reproducibility between two replicates and generalize this concept for a measure of reproducibility of one replicate against the remaining n-1 replicates. We used the rank of the outcome variable and employed the concept of a measure of tracking in the blood pressure literature. We applied the reproducibility measure to two sets of microarray experiments in which one experiment was performed in a more homogeneous environment, resulting in validation of this novel method. The operational interpretation of this measure is clearer than Pearson's correlation coefficient which might be used as a crude measure of reproducibility of two replicates.

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A Study on Adaptive Skin Extraction using a Gradient Map and Saturation Features (경사도 맵과 채도 특징을 이용한 적응적 피부영역 검출에 관한 연구)

  • Hwang, Dae-Dong;Lee, Keun-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4508-4515
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    • 2014
  • Real-time body detection has been researched actively. On the other hand, the detection rate of color distorted images is low because most existing detection methods use static skin color model. Therefore, this paper proposes a new method for detecting the skin color region using a gradient map and saturation features. The basic procedure of the proposed method sequentially consists of creating a gradient map, extracting a gradient feature of skin regions, noise removal using the saturation features of skin, creating a cluster for extraction regions, detecting skin regions using cluster information, and verifying the results. This method uses features other than the color to strengthen skin detection not affected by light, race, age, individual features, etc. The results of the detection rate showed that the proposed method is 10% or more higher than the traditional methods.

Color Transfer Method Based on Separation of Saturation (채색 분리 기반의 색 변환 기법)

  • Kwak, Jung-Min;Kim, Jae-Hyup;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.45 no.3
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    • pp.149-159
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    • 2008
  • We present new methods which transfer the color style of a source image into an arbitrary given reference image. Misidentification problem of color cause wrong indexing in low saturation. Therefore, the proposed method do indexing after Image separating chromatic and achromatic color from saturation. The proposed method is composed of the following four steps : In the first step, Image separate chromatic and achromatic color from saturation using threshold. In the second step, image of separation do indexing using cylindrical metric. In the third step, the number and positional dispersion of pixel decide the order of priority for each index color. And average and standard deviation of each index color be calculated. In the final step, color be transferred in Lab color space, and post processing to removal noise and pseudo-contour. Experimental results show that the proposed method is effective on indexing and color transfer.

Object Recognition and Target Tracking Using Motion Synchronization between Virtual and Real Robots (가상로봇과 실제로봇 사이의 운동 동기화를 통한 물체 인식 및 목표물 추적방안)

  • Ahn, Hyeo Gyeong;Kang, Hyeon Jun;Kim, Jin Beom;Jung, Ji Won;Ok, Seo Won;Kim, Dong Hwan
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.1
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    • pp.20-29
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    • 2017
  • Motion synchronization between developed real and virtual robots for object recognition and target tracking is introduced. ASUS's XTION PRO Live is implemented as a sensor and configured to recognize walls and obstacles, and perceive objects. In order to create virtual reality, Unity 3D is adopted to be associated with the real robot, and the virtual object is controlled by using an input device. A Bluetooth serial communication module is used for wireless communication between the PC and the real robot. The motion information of a virtual object controlled by the user is sent to the robot. Then, the robot moves in the same way as the virtual object according to the motion information. Through motion synchronization, two scenarios, which map the real space and current object information with virtual objects and space, were demonstrated, yielding good agreement between the two spaces.

Integrating Discrete Wavelet Transform and Neural Networks for Prostate Cancer Detection Using Proteomic Data

  • Hwang, Grace J.;Huang, Chuan-Ching;Chen, Ta Jen;Yue, Jack C.;Ivan Chang, Yuan-Chin;Adam, Bao-Ling
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2005.09a
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    • pp.319-324
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    • 2005
  • An integrated approach for prostate cancer detection using proteomic data is presented. Due to the high-dimensional feature of proteomic data, the discrete wavelet transform (DWT) is used in the first-stage for data reduction as well as noise removal. After the process of DWT, the dimensionality is reduced from 43,556 to 1,599. Thus, each sample of proteomic data can be represented by 1599 wavelet coefficients. In the second stage, a voting method is used to select a common set of wavelet coefficients for all samples together. This produces a 987-dimension subspace of wavelet coefficients. In the third stage, the Autoassociator algorithm reduces the dimensionality from 987 to 400. Finally, the artificial neural network (ANN) is applied on the 400-dimension space for prostate cancer detection. The integrated approach is examined on 9 categories of 2-class experiments, and also 3- and 4-class experiments. All of the experiments were run 10 times of ten-fold cross-validation (i. e. 10 partitions with 100 runs). For 9 categories of 2-class experiments, the average testing accuracies are between 81% and 96%, and the average testing accuracies of 3- and 4-way classifications are 85% and 84%, respectively. The integrated approach achieves exciting results for the early detection and diagnosis of prostate cancer.

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An Experimental Study for Preventing the Resonance of Steam Turbine Blade (증기터빈 블레이드의 공진 방지를 위한 실험 연구)

  • 하현천;이동진;류석주
    • Journal of KSNVE
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    • v.11 no.3
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    • pp.410-415
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    • 2001
  • This paper describes an experimental analysis for improving the stability of blade failure due to the vibration resonance, which happens in the low-pressure steam turbine. Some cracks due to high cycle fatigue were found in the blades of a low-pressure turbine after long time operation. Impact test showed that such failure was mainly caused by the resonance. In other words, since one of the natural frequencies of the grouped blade is very close to the excitation frequency of the nozzle, the resonant vibration leads to a large amplitude of displacement and results in a large amount of stress that may cause fatigue failures in the blades. It is interesting that the blade failures occur only at blades neighboring with the nodal points of the natural vibration mode whose natural frequency is close to the nozzle passing frequency. The effective methods for increasing the reliability against the blade vibration are a heightening the fatigue limit of the blade using an advanced material and a removing the resonance away from the operating speed. It is well known that the removal of theresonance could be obtained by the installation of different types of shrouds, wires, and links between the blades as well as by the chance of the number of nozzles. In the present work, two kinds of modification for avoiding the resonance haute been considered; 1) slot-type finger, 2) long span cover. Full-scale mockup tests have been performed in order to confirm the verification for modification in the shop. Test results show that the use of long span cover is very useful to change the natural frequencies of the grouped blade and to avoid the resonance effectively.

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Development of a System for Recognizing Stamp Images (도장영상 인식 시스템의 개발)

  • 송민정;한경숙
    • Journal of Intelligence and Information Systems
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    • v.9 no.1
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    • pp.125-137
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    • 2003
  • In eastern countries stamps have been used more commonly than signatures when approving contracts and documents. Unlike finger prints, stamp images do not share similar patterns to each other and the resolution of stamp images is determined by the input status such as pressure under which stamps are put. This paper discusses the development of a system for recognizing stamp images of Korean or Chinese characters. Recognition of stamp images consists of several steps: acquisition of stamp images from an input device, digitization, contrast stretching, noise removal, and matching. We tested the system on 50 stamp images (20 stamp images of Korean characters, 20 images of Chinese characters, and 10 similar images). There was little difference in discrimination rate between the stamp images of Korean character and those of Chinese characters. 46 stamps images out of 50 were successfully recognized, resulting in 92% discrimination rate. Orientation and pressure under which stamps are put played an important role in determining discrimination rate. Automated stamp image recognition can be made more practical and useful by extending the types of stamp images to ellipses and rectangles and by improving the discrimination rate.

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