• Title/Summary/Keyword: time interpolation

Search Result 750, Processing Time 0.022 seconds

Missing Imputation Methodologies for Daily Traffic Counts by Transforming Time Data into Spatial Data (시간자료의 공간화를 통한 일교통량 결측대체 방법론 연구)

  • Heo, Tae-Young;Oh, Ju-Sam
    • International Journal of Highway Engineering
    • /
    • v.9 no.3
    • /
    • pp.21-28
    • /
    • 2007
  • We suggest a new spatial linear interpolation method to substitute linear interpolation method which widely used in transportation engineering to impute the missing daily traffic volume. We layout daily traffic volume which is time series data over the virtual lattice space to consider the spatial correlation. We used Moran Index to evaluate the spatial correlations among daily traffic volume in same week and same date traffic volume by week considering the circularity of daily traffic volume. For real application, we used daily traffic volume on November, 2004 provided by Korea Institute of Construction Technology(KICT) and transformed daily traffic volume to 4 times 7 virtual lattice space to reflect the spatial correlation. Finally we showed that the spatial linear interpolation method has good performance for missing data imputation based on MAPE, RMSE, and Theil's U criteria.

  • PDF

Estimation of Uncertain Moving Object Location Data

  • Ahn Yoon-Ae;Lee Do-Yeol;Hwang Ho-Young
    • Journal of the Korea Computer Industry Society
    • /
    • v.6 no.3
    • /
    • pp.495-508
    • /
    • 2005
  • Moving objects are spatiotemporal data that change their location or shape continuously over time. Their location coordinates are periodically measured and stored i3l the application systems. The linear function is mainly used to estimate the location information that is not in the system at the query time point. However, a new method is needed to improve uncertainties of the location representation, because the location estimation by linear function induces the estimation error. This paper proposes an application method of the cubic spline interpolation in order to reduce deviation of the location estimation by linear function. First, we define location information of the moving object on the two-dimensional space. Next, we apply the cubic spline interpolation to location estimation of the proposed data model and describe algorithm of the estimation operation. Finally, the precision of this estimation operation model is experimented. The experimentation comes out more accurate results than the method by linear function.

  • PDF

FFT-based Channel Estimation Scheme in LTE-A Downlink System (LTE-A 하향링크 시스템을 위한 새로운 FFT 기반 채널 추정 기법)

  • Moon, Sangmi;Chu, Myeonghun;Kim, Hanjong;Kim, Daejin;Hwang, Intae
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.3
    • /
    • pp.11-20
    • /
    • 2016
  • In this paper, we propose the channel estimation scheme for Long Term Evolution-Advanced (LTE-A) downlink system. The proposed scheme uses the fast fourier transform (FFT) interpolation scheme for the user moving at a high speed. The FFT interpolation scheme converts the channel frequency response obtained from least square (LS) or minimum mean square error (MMSE) channel estimation scheme to time domain channel impulse response by taking the inverse FFT (IFFT). After windowing the channel response in the time domain, we can obtain the channel frequency response by taking the FFT. We perform the system level simulation based on 20MHz bandwidth of 3GPP LTE-A downlink system. Simulation results show that the proposed channel estimation scheme can improve signal-to-noise-plus-interference ratio (SINR), throughput, and spectral efficiency of conventional system.

A Design of Fractional Motion Estimation Engine with 4×4 Block Unit of Interpolator & SAD Tree for 8K UHD H.264/AVC Encoder (8K UHD(7680×4320) H.264/AVC 부호화기를 위한 4×4블럭단위 보간 필터 및 SAD트리 기반 부화소 움직임 추정 엔진 설계)

  • Lee, Kyung-Ho;Kong, Jin-Hyeung
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.6
    • /
    • pp.145-155
    • /
    • 2013
  • In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Fractional Motion Estimation in 8K UHD($7680{\times}4320$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $10{\times}10$ reference data for interpolation, we design 2D cache buffer which consists of the $10{\times}10$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The gate count is 436.5Kgates. The proposed H.264/AVC Fractional Motion Estimation can support 8K UHD at 30 frames per second by running at 187MHz.

Two-dimensional Spatial Distribution Analysis Using Water Quality Measurement Results at River Junctions (하천 합류부에서의 수질계측결과를 활용한 2차원 공간분포 해석)

  • Lee, Chang Hyun;Park, Jae Gon;Kim, Kyung Dong;Ryu, Si Wan;Kim, Dong Su;Kim, Young Do
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.42 no.3
    • /
    • pp.343-350
    • /
    • 2022
  • High-resolution data are needed to understand water body mixing patterns at river junctions. In particular, in river analysis, hydrological and water quality characteristics are used as basic data for aquatic ecological health, so observation through continuous monitoring is necessary. In addition, since measurement is carried out through a one-dimensional and fixed measurement method in existing monitoring systems, a hydrological and water quality characteristics investigation of an entire river, except for in the immediate vicinity of the measurement point, is not undertaken. In order to obtain high-resolution measurement data, a measurer has to consider multiple factors, and the area or time that can be measured is limited. Although the resolution might be lowered, an appropriate interpolation method must be selected in order to acquire a wide range of data. Therefore, in this study, a high-elevation measurement method at a river junction was introduced, and the interpolation method according to the measurement results was compared. The overall hydraulic and water quality information of the river was indicated through the visualization of the prediction and interpolation method in the low-resolution measurement result. By comparing each interpolation method, Inverse Distance Weighting, Natural Neighbor, and Kriging techniques were applied in river mapping to improve the precision of river mapping through visualized data and quantitative evaluation. It is thought that this study will offer a new method for measuring rivers through spatial interpolation.

Real-Time Depth of Field Rendering Using Anisotropically Filtered Mipmap Interpolation (이방성으로 필터링된 밉맵의 보간을 이용한 실시간 필드심도 렌더링)

  • Lee, Sung-Kil;Kim, Gerard Joung-Hyun;Choi, Seung-Moon
    • 한국HCI학회:학술대회논문집
    • /
    • 2008.02a
    • /
    • pp.33-38
    • /
    • 2008
  • 본 논문은 핀홀 카메라 모델에 의해 렌더링한 컬러와 깊이 이미지의 후처리에 의한 실시간 필드심도 렌더링 방법을 제안한다. 필드심도 렌더링은 최근의 향상에도, 큰 스케일의 블러링에 필요한 계산 때문에 실용적으로 사용되지 못해 왔다. 본 방법은 이방성 가우시안 필터로 생성된 밉맵 이미지들을 비선형으로 보간하여 필드심도 효과에 필요한 블러링을 수행한다. 모든 계산 과정은 GPU로 가속되어, 안정적이고 확장 가능한 실시간 수행 성능을 확보한다. 또한, 후처리 방식의 두 가지 결점인 강도 누출과 블러링 불연속성을 이방성 가우시안 필터와 블러링 정도를 부드럽게 하여 제거한다. 본 방법은 뛰어난 실시간 성능과 함께 고품질의 필드심도 효과를 생성한다.

  • PDF

Continuous Location Tracking Algorithm for Moving Position Data

  • Ahn, Yoon-Ae
    • Journal of the Korean Data and Information Science Society
    • /
    • v.19 no.3
    • /
    • pp.979-994
    • /
    • 2008
  • Moving objects are spatio-temporal data that change their location or shape continuously over time. Generally, if continuously moving objects are managed by a conventional database management system, the system cannot properly process the past and future location which is not stored in the database. Up to now, for the purpose of location tracking which is not stored, the linear interpolation to estimate the past location has been usually used. It is suitable for the moving objects on linear route, not curved route. In this paper, we propose a past location tracking algorithm for a moving object on curved routes, and also suggest a future location tracking algorithm using some past location information. We found that the proposed location tracking algorithm has higher accuracy than the linear interpolation function.

  • PDF

Numerical Flow Analysis of Ducted Marine Propeller with Pre-Swirl Guidevane (전치 가이드베인을 가지는 수중 덕트 프로펠러 주위의 전산 유동 해석)

  • Yu Hye-Ran;Jung Young-Rae;Park Warn-Gyu
    • Journal of computational fluids engineering
    • /
    • v.9 no.2
    • /
    • pp.62-69
    • /
    • 2004
  • The present work solved 3D incompressible RANS equations on a rotating, multi-blocked grid system to efficiently analyze ducted marine propulsor with the interaction of propeller guidevane and annular duct. To handle the interface boundary between the guidevane and the propeller, a sliding multiblock technique based on the cubic spline interpolation was applied. To validate the present code, a turbine flow was simulated and the time-averaged pressure coefficients were compared with experiment. After the code validation, the flowfield around a ducted marine propeller with pre-swirl guidevane was simulated.

Language Model Adaptation for Broadcast News Recognition (방송 뉴스 인식을 위한 언어 모델 적응)

  • Kim Hyun Suk;Jeon Hyung Bae;Kim Sanghun;Choi Joon Ki;Yun Seung
    • MALSORI
    • /
    • no.51
    • /
    • pp.99-115
    • /
    • 2004
  • In this parer, we propose LM adaptation for broadcast news recognition. We collect information of recent articles from the internet on real time, make a recent small size LM, and then interpolate recent LM with a existing LM composed of existing large broadcast news corpus. We performed interpolation experiments to get the best type of articles from recent corpus because collected recent corpus is composed of articles which are related with test set, and which are unrelated. When we made an adapted LM using recent LM with similar articles to test set through Tf-Idf method and existing LM, we got the best result that ERR of pseudo-morpheme based recognition performance has 17.2 % improvement and the number of OOV has reduction from 70 to 27.

  • PDF