• Title/Summary/Keyword: Parallel data processing

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A Simple Multi-rate Parallel Interference Canceller for the IMT-2000 3GPP System (IMT-2000 3GPP 시스템을 위한 간단한 다중 전송률 병렬형 간섭제거기)

  • Kim, Jin-Kyeom;Oh, Seong-Keun;Sunwoo, Myung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.38 no.12
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    • pp.10-19
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    • 2001
  • In this paper, we propose an effective but simple multi-rate parallel interference canceller(PIC) for the international mobile telecommunications-2000(IMT-2000) 3rd generation partnership project (3GPP) system. For effective multi-rate processing, we define the basic block as one symbol period of the dedicated physical control channel(DPCCH) having the lowest data rate and common to all users. Then, decision and interference cancellation are performed at every basic block. For an asynchronous channel, we propose an advance removal scheme that removes in advance multiple access interference(MAI) due to the next blockof other users with shorter delay. Introducing a pipeline structure at a sample base, we can implement efficiently the PIC using the advance removal scheme with a minimum hardware and no extra computations. Through computer simulations, we analyze the bit error rate(BER) performance of the proposed PIC with respect to signal-to-noise ratio(SNR) and the number of users.

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Parallelizing 3D Frequency-domain Acoustic Wave Propagation Modeling using a Xeon Phi Coprocessor (제온 파이 보조 프로세서를 이용한 3차원 주파수 영역 음향파 파동 전파 모델링 병렬화)

  • Ryu, Donghyun;Jo, Sang Hoon;Ha, Wansoo
    • Geophysics and Geophysical Exploration
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    • v.20 no.3
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    • pp.129-136
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    • 2017
  • 3D seismic data processing methods such as full waveform inversion or reverse-time migration require 3D wave propagation modeling and heavy calculations. We compared efficiency and accuracy of a Xeon Phi coprocessor to those of a high-end server CPU using 3D frequency-domain wave propagation modeling. We adopted the OpenMP parallel programming to the time-domain finite difference algorithm by considering the characteristics of the Xeon Phi coprocessors. We applied the Fourier transform using a running-integration to obtain the frequency-domain wavefield. A numerical test on frequency-domain wavefield modeling was performed using the 3D SEG/EAGE salt velocity model. Consequently, we could obtain an accurate frequency-domain wavefield and attain a 1.44x speedup using the Xeon Phi coprocessor compared to the CPU.

Parallel Spatial Join Method Using Efficient Spatial Relation Partition In Distributed Spatial Database Systems (분산 공간 DBMS에서의 효율적인 공간 릴레이션 분할 기법을 이용한 병렬 공간 죠인 기법)

  • Ko, Ju-Il;Lee, Hwan-Jae;Bae, Hae-Young
    • Journal of Korea Spatial Information System Society
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    • v.4 no.1 s.7
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    • pp.39-46
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    • 2002
  • In distributed spatial database systems, users nay issue a query that joins two relations stored at different sites. The sheer volume and complexity of spatial data bring out expensive CPU and I/O costs during the spatial join processing. This paper shows a new spatial join method which joins two spatial relation in a parallel way. Firstly, the initial join operation is divided into two distinct ones by partitioning one of two participating relations based on the region. This two join operations are assigned to each sites and executed simultaneously. Finally, each intermediate result sets from the two join operations are merged to an ultimate result set. This method reduces the number of spatial objects participating in the spatial operations. It also reduces the scope and the number of scanning spatial indices. And it does not materialize the temporary results by implementing the join algebra operators using the iterator. The performance test shows that this join method can lead to efficient use in terms of buffer and disk by narrowing down the joining region and decreasing the number of spatial objects.

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OPENMP PARALLEL PERFORMANCE OF A CFD CODE ON MULTI-CORE SYSTEMS (멀티코어 시스템에서 쓰레드 수에 따른 CFD 코드의 OpenMP 병렬 성능)

  • Kim, J.K.;Jang, K.J.;Kim, T.Y.;Cho, D.R.;Kim, S.D.;Choi, J.Y.
    • Journal of computational fluids engineering
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    • v.18 no.1
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    • pp.83-90
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    • 2013
  • OpenMP is becoming more and more useful as a simple parallel processing paradigm on SMP (Shared Memory Multi-Processors) computing environment with the development of multi-core processors. However, very few data is available publically regarding the OpenMP performance in CFD (Computational Fluid Dynamics). In the present study a CFD test suite is prepared for the performance evaluation of OpenMP on various multi-core systems. The test suite is composed of two-dimensional numerical simulations for inviscid/viscous and reacting/non-reacting flows using three different levels of grid systems. One to five test runs were carried out on various systems from dual-core dual threads to 16-core 32-threads systems by changing the number of threads engaged for each test up to 80. The results exhibit some interesting results and the lessons learned from the tests would be quite helpful for the further use of OpenMP for CFD studies using multi-core processor systems.

Disk Cache Manager based on Minix3 Microkernel : Design and Implementation (Minix3 마이크로커널 기반 디스크 캐쉬 관리자의 설계 및 구현)

  • Choi, Wookjin;Kang, Yongho;Kim, Seonjong;Kwon, Hyeogsoong;Kim, Jooman
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.421-427
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    • 2013
  • Disk Cache Manager(DCM), a functional server of microkernel based, to improve the I/O power of shared disks is designed and implemented in this work. DCM interfaces other different servers with message passing through ports by serving as a system actor the multi-thread mode on the Minix3 micro-kernel. DCM proposed in this paper uses the shared disk logically as a Seven Disk and Sodd Disk to enable parallel I/O. DCM enables the efficient placement of disk data because it raises disk cache hit-ratio by increasing the cache size when the utilization of the particular disk is high. Through experimental results, we show that DCM is quite efficient for a shared disk with higher utilization.

Development of Unwrapped InSAR Phase to Height Conversion Algorithm (레이더 간섭위상의 정밀고도변환 알고리즘 개선)

  • Kim, Sang-Wan
    • Korean Journal of Remote Sensing
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    • v.28 no.2
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    • pp.227-235
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    • 2012
  • The InSAR (Interferometric SAR) processing steps for DEM generation consist of the coregistration of two SAR data, interferogram generation, phase filtering, phase unwrapping, phase to height conversion, and geocoding, etc. In this study, we developed the precise algorithm for phase to height conversion, including the ambiguity method taking into account Earth ellipsoid, Schw$\ddot{a}$visch method, and the refined ambiguity method suitable for the interferometric pair with non-parallel obit. From the testing with JERS-1 orbit we found that the height error by traditional ambiguity method reaches to about 40 m during phase to height conversion. The proposed methods are very useful in generating precise InSAR DEM;especially in the case of using non-parallel InSAR pair due to unstable orbit control such as JERS-1 or intentional orbit control such as Cross-InSAR pair between ERS2 and ENVISAT satellite.

Optimal Design Space Exploration of Multi-core Architecture for Real-time Lane Detection Algorithm (실시간 차선인식 알고리즘을 위한 최적의 멀티코어 아키텍처 디자인 공간 탐색)

  • Jeong, Inkyu;Kim, Jongmyon
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.3
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    • pp.339-349
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    • 2017
  • This paper proposes a four-stage algorithm for detecting lanes on a driving car. In the first stage, it extracts region of interests in an image. In the second stage, it employs a median filter to remove noise. In the third stage, a binary algorithm is used to classify two classes of backgrond and foreground of an input image. Finally, an image erosion algorithm is utilized to obtain clear lanes by removing noises and edges remained after the binary process. However, the proposed lane detection algorithm requires high computational time. To address this issue, this paper presents a parallel implementation of a real-time line detection algorithm on a multi-core architecture. In addition, we implement and simulate 8 different processing element (PE) architectures to select an optimal PE architecture for the target application. Experimental results indicate that 40×40 PE architecture show the best performance, energy efficiency and area efficiency.

Sentiment Analysis of Movie Review Using Integrated CNN-LSTM Mode (CNN-LSTM 조합모델을 이용한 영화리뷰 감성분석)

  • Park, Ho-yeon;Kim, Kyoung-jae
    • Journal of Intelligence and Information Systems
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    • v.25 no.4
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    • pp.141-154
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    • 2019
  • Rapid growth of internet technology and social media is progressing. Data mining technology has evolved to enable unstructured document representations in a variety of applications. Sentiment analysis is an important technology that can distinguish poor or high-quality content through text data of products, and it has proliferated during text mining. Sentiment analysis mainly analyzes people's opinions in text data by assigning predefined data categories as positive and negative. This has been studied in various directions in terms of accuracy from simple rule-based to dictionary-based approaches using predefined labels. In fact, sentiment analysis is one of the most active researches in natural language processing and is widely studied in text mining. When real online reviews aren't available for others, it's not only easy to openly collect information, but it also affects your business. In marketing, real-world information from customers is gathered on websites, not surveys. Depending on whether the website's posts are positive or negative, the customer response is reflected in the sales and tries to identify the information. However, many reviews on a website are not always good, and difficult to identify. The earlier studies in this research area used the reviews data of the Amazon.com shopping mal, but the research data used in the recent studies uses the data for stock market trends, blogs, news articles, weather forecasts, IMDB, and facebook etc. However, the lack of accuracy is recognized because sentiment calculations are changed according to the subject, paragraph, sentiment lexicon direction, and sentence strength. This study aims to classify the polarity analysis of sentiment analysis into positive and negative categories and increase the prediction accuracy of the polarity analysis using the pretrained IMDB review data set. First, the text classification algorithm related to sentiment analysis adopts the popular machine learning algorithms such as NB (naive bayes), SVM (support vector machines), XGboost, RF (random forests), and Gradient Boost as comparative models. Second, deep learning has demonstrated discriminative features that can extract complex features of data. Representative algorithms are CNN (convolution neural networks), RNN (recurrent neural networks), LSTM (long-short term memory). CNN can be used similarly to BoW when processing a sentence in vector format, but does not consider sequential data attributes. RNN can handle well in order because it takes into account the time information of the data, but there is a long-term dependency on memory. To solve the problem of long-term dependence, LSTM is used. For the comparison, CNN and LSTM were chosen as simple deep learning models. In addition to classical machine learning algorithms, CNN, LSTM, and the integrated models were analyzed. Although there are many parameters for the algorithms, we examined the relationship between numerical value and precision to find the optimal combination. And, we tried to figure out how the models work well for sentiment analysis and how these models work. This study proposes integrated CNN and LSTM algorithms to extract the positive and negative features of text analysis. The reasons for mixing these two algorithms are as follows. CNN can extract features for the classification automatically by applying convolution layer and massively parallel processing. LSTM is not capable of highly parallel processing. Like faucets, the LSTM has input, output, and forget gates that can be moved and controlled at a desired time. These gates have the advantage of placing memory blocks on hidden nodes. The memory block of the LSTM may not store all the data, but it can solve the CNN's long-term dependency problem. Furthermore, when LSTM is used in CNN's pooling layer, it has an end-to-end structure, so that spatial and temporal features can be designed simultaneously. In combination with CNN-LSTM, 90.33% accuracy was measured. This is slower than CNN, but faster than LSTM. The presented model was more accurate than other models. In addition, each word embedding layer can be improved when training the kernel step by step. CNN-LSTM can improve the weakness of each model, and there is an advantage of improving the learning by layer using the end-to-end structure of LSTM. Based on these reasons, this study tries to enhance the classification accuracy of movie reviews using the integrated CNN-LSTM model.

A Design of the OOPP(Optimized Online Portfolio Platform) using Enterprise Competency Information (기업 직무 정보를 활용한 OOPP(Optimized Online Portfolio Platform)설계)

  • Jung, Bogeun;Park, Jinuk;Lee, ByungKwan
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.5
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    • pp.493-506
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    • 2018
  • This paper proposes the OOPP(Optimized Online Portfolio Platform) design for the job seekers to search for the job competency necessary for employment and to write and manage portfolio online efficiently. The OOPP consists of three modules. First, JDCM(Job Data Collection Module) stores the help-wanted advertisements of job information sites in a spreadsheet. Second, CSM(Competency Statistical Model) classifies core competencies for each job by text-mining the collected help-wanted ads. Third, OBBM(Optimize Browser Behavior Module) makes users to look up data rapidly by improving the processing speed of a browser. In addition, The OBBM consists of the PSES(Parallel Search Engine Sub-Module) optimizing the computation of a Search Engine and the OILS(Optimized Image Loading Sub-Module) optimizing the loading of image text, etc. The performance analysis of the CSM shows that there is little difference in accuracy between the CSM and the actual advertisement because its data accuracy is 99.4~100%. If Browser optimization is done by using the OBBM, working time is reduced by about 68.37%. Therefore, the OOPP makes users look up the analyzed result in the web page rapidly by analyzing the help-wanted ads. of job information sites accurately.

A Method for Group Mobility Model Construction and Model Representation from Positioning Data Set Using GPGPU (GPGPU에 기반하는 위치 정보 집합에서 집단 이동성 모델의 도출 기법과 그 표현 기법)

  • Song, Ha Yoon;Kim, Dong Yup
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.3
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    • pp.141-148
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    • 2017
  • The current advancement of mobile devices enables users to collect a sequence of user positions by use of the positioning technology and thus the related research regarding positioning or location information are quite arising. An individual mobility model based on positioning data and time data are already established while group mobility model is not done yet. In this research, group mobility model, an extension of individual mobility model, and the process of establishment of group mobility model will be studied. Based on the previous research of group mobility model from two individual mobility model, a group mobility model with more than two individual model has been established and the transition pattern of the model is represented by Markov chain. In consideration of real application, the computing time to establish group mobility mode from huge positioning data has been drastically improved by use of GPGPU comparing to the use of traditional multicore systems.