• 제목/요약/키워드: data recover

검색결과 490건 처리시간 0.037초

순환유동층보일러 외부열교환기의 열전달 특성에 관한 수치해석적 연구 (A Numerical Study of the Characteristics of Heat Transfer in External Heat Exchanger of CFB Boiler)

  • 황문경;김정래
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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    • pp.15-16
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    • 2014
  • With the increasing trend in CFB(Circulating Fluidized Bed) boiler scale, the EHE(External Heat Exchanger) must be adopted to the large-scale boilers to recover insufficient heat transfer surface. In this study, the numerical analysis model for EHE in commercial 300MWe CFB boiler was developed with the inclusion of mechanistic model, which enables the heat transfer prediction. Finally, the calculated absorbed heat and derived heat transfer coefficient are evaluated through the verification with experimental data.

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The Nonparametric Deconvolution Problem with Gaussian Error Distribution

  • Cho, Wan-Hyun;Park, Jeong-Soo
    • Journal of the Korean Statistical Society
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    • 제25권2호
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    • pp.265-276
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    • 1996
  • The nonparametric deconvolution problems are studied to recover an unknown density when the data are contaminated with Gaussian error. We propose the estimator which is a linear combination of kernel type estimates of derivertives of the observed density function. We show that this estimator is consistent and also consider the properties of estimator at small sample by simulation.

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유전적 프로그래밍을 이용한 노이지 데이터의 Curve Fitting과 선박설계에서의 적용 (Genetic Programming Approach to Curve Fitting of Noisy Data and Its Application In Ship Design)

  • 이경호;연윤석
    • 한국CDE학회논문집
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    • 제9권3호
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    • pp.183-191
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    • 2004
  • This paper deals with smooth curve fitting of data corrupt by noise. Most research efforts have been concentrated on employing the smoothness penalty function with the estimation of its optimal parameter in order to avoid the 'overfilling and underfitting' dilemma in noisy data fitting problems. Our approach, called DBSF(Differentiation-Based Smooth Fitting), is different from the above-mentioned method. The main idea is that optimal functions approximately estimating the derivative of noisy curve data are generated first using genetic programming, and then their integral values are evaluated and used to recover the original curve form. To show the effectiveness of this approach, DBSP is demonstrated by presenting two illustrative examples and the application of estimating the principal dimensions of bulk cargo ships in the conceptual design stage.

Statistical Analysis of Bivariate Recurrent Event Data with Incomplete Observation Gaps

  • Kim, Yang-Jin
    • Communications for Statistical Applications and Methods
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    • 제20권4호
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    • pp.283-290
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    • 2013
  • Subjects can experience two types of recurrent events in a longitudinal study. In addition, there may exist intermittent dropouts that results in repeated observation gaps during which no recurrent events are observed. Therefore, theses periods are regarded as non-risk status. In this paper, we consider a special case where information on the observation gap is incomplete, that is, the termination time of observation gap is not available while the starting time is known. For a statistical inference, incomplete termination time is incorporated in terms of interval-censored data and estimated with two approaches. A shared frailty effect is also employed for the association between two recurrent events. An EM algorithm is applied to recover unknown termination times as well as frailty effect. We apply the suggested method to young drivers' convictions data with several suspensions.

고속 직렬 디스플레이 인터페이스를 위한 1/4-rate 클록 데이터 복원회로 설계 (Design of 1/4-rate Clock and Date Recovery Circuit for High-speed Serial Display Interface)

  • 정기상;김강직;조성익
    • 전기학회논문지
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    • 제60권2호
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    • pp.455-458
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    • 2011
  • 4:10 deserializer is proposed to recover 1:10 serial data using 1/4-rate clock. And then, 1/4-rate CDR(Clock and Data Recovery) circuit was designed for SERDES of high-speed serial display interface. The reduction of clock frequency using 1/4-rate clocking helps relax the speed limitation when higher data transfer is demanded. This circuit is composed of 1/4-rate sampler, PEL(Phase Error Logic), Majority Voting, Digital Filter, DPC(Digital to Phase Converter) and 4:10 deserializer. The designed CDR has been designed in a standard $0.18{\mu}m$ 1P6M CMOS technology and the recovered data jitter is 14ps in simulation.

Improve object recognition using UWB SAR imaging with compressed sensing

  • Pham, The Hien;Hong, Ic-Pyo
    • 전기전자학회논문지
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    • 제25권1호
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    • pp.76-82
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    • 2021
  • In this paper, the compressed sensing basic pursuit denoise algorithm adopted to synthetic aperture radar imaging is investigated to improve the object recognition. From the incomplete data sets for image processing, the compressed sensing algorithm had been integrated to recover the data before the conventional back- projection algorithm was involved to obtain the synthetic aperture radar images. This method can lead to the reduction of measurement events while scanning the objects. An ultra-wideband radar scheme using a stripmap synthetic aperture radar algorithm was utilized to detect objects hidden behind the box. The Ultra-Wideband radar system with 3.1~4.8 GHz broadband and UWB antenna were implemented to transmit and receive signal data of two conductive cylinders located inside the paper box. The results confirmed that the images can be reconstructed by using a 30% randomly selected dataset without noticeable distortion compared to the images generated by full data using the conventional back-projection algorithm.

Reversible Data Hiding Based on Block Median Preservation and image local characteristic

  • Qu, Xiao-Chao;Kim, Hyoung-Joong
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2011년도 춘계학술발표대회
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    • pp.986-989
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    • 2011
  • Reversible data hiding is a technique that can embed information into cover media (image, video, voice signal) and can recover the original cover media after extracting the embedded information. In this papa, we propose a new reversible data hiding methods that based on block median preservation and the image local characteristic. By using the median value of a block, a high payload can be got and by considering the image local characteristic, a lot of distortion can be avoided and a high PSNR can be got. In the experiment, our methods can generate better result than the previous reversible data hiding methods.

RPIDA: Recoverable Privacy-preserving Integrity-assured Data Aggregation Scheme for Wireless Sensor Networks

  • Yang, Lijun;Ding, Chao;Wu, Meng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권12호
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    • pp.5189-5208
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    • 2015
  • To address the contradiction between data aggregation and data security in wireless sensor networks, a Recoverable Privacy-preserving Integrity-assured Data Aggregation (RPIDA) scheme is proposed based on privacy homomorphism and aggregate message authentication code. The proposed scheme provides both end-to-end privacy and data integrity for data aggregation in WSNs. In our scheme, the base station can recover each sensing data collected by all sensors even if these data have been aggregated by aggregators, thus can verify the integrity of all sensing data. Besides, with these individual sensing data, base station is able to perform any further operations on them, which means RPIDA is not limited in types of aggregation functions. The security analysis indicates that our proposal is resilient against typical security attacks; besides, it can detect and locate the malicious nodes in a certain range. The performance analysis shows that the proposed scheme has remarkable advantage over other asymmetric schemes in terms of computation and communication overhead. In order to evaluate the performance and the feasibility of our proposal, the prototype implementation is presented based on the TinyOS platform. The experiment results demonstrate that RPIDA is feasible and efficient for resource-constrained sensor nodes.

표준기상데이터 작성 시 누락된 풍속 데이터의 보간 방법 제안 (A Proposal of an Interpolation Method of Missing Wind Velocity Data in Writing a Typical Weather Data)

  • 박소우;김주욱;송두삼
    • 한국태양에너지학회 논문집
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    • 제37권6호
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    • pp.79-91
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    • 2017
  • The meteorological data of 1 hour interval are required to write a typical weather data for building energy simulation. However, many meterological data are missing and the interpolation method to recover the missing data is required. Especially, lots of meterological data are replicated by linear interpolation method because the changes are not significant. While, the wind velocity fluctuates with the time or locations, so linear interpolation method is not appropriate in interpolation of the wind velocity data. In this study, three interpolation methods, using surrounding wind velocity data, Inverse Distance Weighting (IDW), Revised Inverse Distance Weighting (IDW-r), were analyzed considering the characteristics of wind velocity. The Revised Inverse Distance Weighting method, proposed in this study, showed the highest reliability in restoration of the wind velocity data among the analyzed methods.

Deformable Surface 3D Reconstruction from a Single Image by Linear Programming

  • Ma, Wenjuan;Sun, Shusen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권6호
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    • pp.3121-3142
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    • 2017
  • We present a method for 3D shape reconstruction of inextensible deformable surfaces from a single image. The key of our approach is to represent the surface as a 3D triangulated mesh and formulate the reconstruction problem as a sequence of Linear Programming (LP) problems. The LP problem consists of data constraints which are 3D-to-2D keypoint correspondences and shape constraints which are designed to retain original lengths of mesh edges. We use a closed-form method to generate an initial structure, then refine this structure by solving the LP problem iteratively. Compared with previous methods, ours neither involves smoothness constraints nor temporal consistency, which enables us to recover shapes of surfaces with various deformations from a single image. The robustness and accuracy of our approach are evaluated quantitatively on synthetic data and qualitatively on real data.