• Title/Summary/Keyword: science-specific error

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Energy-efficient Reconfigurable FEC Processor for Multi-standard Wireless Communication Systems

  • Li, Meng;der Perre, Liesbet Van;van Thillo, Wim;Lee, Youngjoo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.3
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    • pp.333-340
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    • 2017
  • In this paper, we describe HW/SW co-optimizations for reconfigurable application specific instruction-set processors (ASIPs). Based on our previous very long instruction word (VLIW) ASIP, the proposed framework realizes various forward error-correction (FEC) algorithms for wireless communication systems. In order to enhance the energy efficiency, we newly introduce several design methodologies including high-radix algorithms, task-level out-of-order executions, and intensive resource allocations with loop-level rescheduling. The case study on the radix-4 turbo decoding shows that the proposed techniques improve the energy efficiency by 3.7 times compared to the previous architecture.

Analysis of Several Digital Network Technologies for Hard Real-time Communications in Nuclear Plant

  • Song, Ki-Sang;No, Hee-Cheon;Kim, Dong-Hun;Koo, In-Soo
    • Nuclear Engineering and Technology
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    • v.31 no.2
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    • pp.226-235
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    • 1999
  • Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation-critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Token Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity from electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant.

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Wavelet Estimation of Regression Functions with Errors in Variables

  • Kim, Woo-Chul;Koo, Ja-Yong
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.849-860
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    • 1999
  • This paper addresses the issue of estimating regression function with errors in variables using wavelets. We adopt a nonparametric approach in assuming that the regression function has no specific parametric form, To account for errors in covariates deconvolution is involved in the construction of a new class of linear wavelet estimators. using the wavelet characterization of Besov spaces the question of regression estimation with Besov constraint can be reduced to a problem in a space of sequences. Rates of convergence are studied over Besov function classes $B_{spq}$ using $L_2$ error measure. It is shown that the rates of convergence depend on the smoothness s of the regression function and the decay rate of characteristic function of the contaminating error.

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Extended Kalman Filter-based Localization with Kinematic Relationship of Underwater Structure Inspection Robots (수중 구조물 검사로봇의 기구학적 관계를 이용한 확장 칼만 필터 기반의 위치추정)

  • Heo, Young-Jin;Lee, Gi-Hyeon;Kim, Jinhyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.4
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    • pp.372-378
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    • 2013
  • In this paper, we research the localization problem of the crawler-type inspection robot for underwater structure which travels an outer wall of underwater structure. Since various factors of the underwater environment affect an encoder odometer, it is hard to localize robot itself using only on-board sensors. So in this research we used a depth sensor and an IMU to compensate odometer which has extreme error in the underwater environment through using Extended Kalman Filter(EKF) which is normally used in mobile robotics. To acquire valid measurements, we implemented precision sensor modeling after assuming specific situation that robot travels underwater structure. The depth sensor acquires a vertical position of robot and compensates one of the robot pose, and IMU is used to compensate a bearing. But horizontal position of robot can't be compensated by using only on-board sensors. So we proposed a localization algorithm which makes horizontal direction error bounded by using kinematics relationship. Also we implemented computer simulations and experiments in underwater environment to verify the algorithm performance.

Partial Least Squares Analysis on Near-Infrared Absorbance Spectra by Air-dried Specific Gravity of Major Domestic Softwood Species

  • Yang, Sang-Yun;Park, Yonggun;Chung, Hyunwoo;Kim, Hyunbin;Park, Se-Yeong;Choi, In-Gyu;Kwon, Ohkyung;Cho, Kyu-Chae;Yeo, Hwanmyeong
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.4
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    • pp.399-408
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    • 2017
  • Research on the rapid and accurate prediction of physical properties of wood using near-infrared (NIR) spectroscopy has attracted recent attention. In this study, partial least squares analysis was performed between NIR spectra and air-dried specific gravity of five domestic conifer species including larch (Larix kaempferi), Korean pine (Pinus koraiensis), red pine (Pinus densiflora), cedar (Cryptomeria japonica), and cypress (Chamaecyparis obtusa). Fifty different lumbers per species were purchased from the five National Forestry Cooperative Federations of Korea. The air-dried specific gravity of 100 knot- and defect-free specimens of each species was determined by NIR spectroscopy in the range of 680-2500 nm. Spectral data preprocessing including standard normal variate, detrend and forward first derivative (gap size = 8, smoothing = 8) were applied to all the NIR spectra of the specimens. Partial least squares analysis including cross-validation (five groups) was performed with the air-dried specific gravity and NIR spectra. When the performance of the regression model was expressed as $R^2$ (coefficient of determination) and root mean square error of calibration (RMSEC), $R^2$ and RMSEC were 0.63 and 0.027 for larch, 0.68 and 0.033 for Korean pine, 0.62 and 0.033 for red pine, 0.76 and 0.022 for cedar, and 0.79 and 0.027 for cypress, respectively. For the calibration model, which contained all species in this study, the $R^2$ was 0.75 and the RMSEC was 0.37.

Comparison of reference evapotranspiration estimation methods with limited data in South Korea

  • Jeon, Min-Gi;Nam, Won-Ho;Hong, Eun-Mi;Hwang, Seonah;Ok, Junghun;Cho, Heerae;Han, Kyung-Hwa;Jung, Kang-Ho;Zhang, Yong-Seon;Hong, Suk-Young
    • Korean Journal of Agricultural Science
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    • v.46 no.1
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    • pp.137-149
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    • 2019
  • Accurate estimation of reference evapotranspiration (RET) is important to quantify crop evapotranspiration for sustainable water resource management in hydrological, agricultural, and environmental fields. It is estimated by different methods from direct measurements with lysimeters, or by many empirical equations suggested by numerous modeling using local climatic variables. The potential to use some such equations depends on the availability of the necessary meteorological parameters for calculating the RET in specific climatic conditions. The objective of this study was to determine the proper RET equations using limited climatic data and to analyze the temporal and spatial trends of the RET in South Korea. We evaluated the FAO-56 Penman-Monteith equation (FAO-56 PM) by comparing several simple RET equations and observed small fan evaporation. In this study, the modified Penman equation, Hargreaves equation, and FAO Penman-Monteith equation with missing solar radiation (PM-Rs) data were tested to estimate the RET. Nine weather stations were considered with limited climatic data across South Korea from 1973 - 2017, and the RET equations were calculated for each weather station as well as the analysis of the mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The FAO-56 PM recommended by the Food Agriculture Organization (FAO) showed good performance even though missing solar radiation, relative humidity, and wind speed data and could still be adapted to the limited data conditions. As a result, the RET was increased, and the evapotranspiration rate was increased more in coastal areas than inland.

Covid19 trends predictions using time series data (시계열 데이터를 활용한 코로나19 동향 예측)

  • Kim, Jae-Ho;Kim, Jang-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.7
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    • pp.884-889
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    • 2021
  • The number of people infected with Covid-19 in Korea seemed to be gradually decreasing thanks to various efforts such as social distancing and vaccines. However, just as the number of infected people increased after a particular incident on February 20, 2020, the number of infected people has been increasing rapidly since December 2020 by approximately 500 per day. Therefore, the future Covid-19 is predicted through the Prophet algorithm using Kaggle's dataset, and the explanatory power for this prediction is added through the coefficient of determination, mean absolute error, mean percent error, mean square difference, and mean square deviation through Scikit-learn. Moreover, in the absence of a specific incident rapidly increasing the cases of Covid-19, the proposed method predicts the number of infected people in Korea and emphasizes the importance of implementing epidemic prevention and quarantine rules for future diseases.

NMR Structural Study of the 3'-T.G Mismatched DNA Decamer Duplex Containing the T-T (6-4) Adduct

  • Lee, Joon-Hwa;Park, Yun-Jeong;Park, Byong-Seok
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.1
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    • pp.60-70
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    • 1999
  • The pyrimidine(6-4) pyrimidone photoproduct [(6-4) adduct] is one of the major photoproducts induced by UV irradiation of DNA and occurs at TpT sites. The (6-4) adduct is highly mutagenic and specific during translesion replication. The marked preference for insertion of A opposite the 5'-T and G opposite the 3--T of the (6-4) adducts leads to a predominantly 3'-T\longrightarrowC transition with 85% replicating error rate. In order to obtain insight into the origin of 3'-T\longrightarrowC transition induced by the (6-4) adduct, we have performed one - and two-dimensional NMR experiment. The 3'-Tof the (6-4) lesion forms the stable hydrogen bonding to the imino proton of an opposed G, which stabilizes the overall helix and diminishes the highly distorted conformation caused by the (6-4) lesion in the (6-4)/AA duplex. We proposed that the greater insertion of a G over an A opposite the 3'-T of the (6-4) lesion These results may account for the greater preference for the insertion of a G over a A opposite the 3'-T of the (6-4) lesion. Thus this insertion leads to the highly specific 3'-T\longrightarrowC multation at the (6-4) lesion site.

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Person Re-identification using Sparse Representation with a Saliency-weighted Dictionary

  • Kim, Miri;Jang, Jinbeum;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.6 no.4
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    • pp.262-268
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    • 2017
  • Intelligent video surveillance systems have been developed to monitor global areas and find specific target objects using a large-scale database. However, person re-identification presents some challenges, such as pose change and occlusions. To solve the problems, this paper presents an improved person re-identification method using sparse representation and saliency-based dictionary construction. The proposed method consists of three parts: i) feature description based on salient colors and textures for dictionary elements, ii) orthogonal atom selection using cosine similarity to deal with pose and viewpoint change, and iii) measurement of reconstruction error to rank the gallery corresponding a probe object. The proposed method provides good performance, since robust descriptors used as a dictionary atom are generated by weighting some salient features, and dictionary atoms are selected by reducing excessive redundancy causing low accuracy. Therefore, the proposed method can be applied in a large scale-database surveillance system to search for a specific object.

Evaluation of the Utility of a Volumetric Modulated Arc Therapy Specific Patient Quality Assurance using Software-based Quality Assurance System (소프트웨어 기반 정도관리 시스템을 이용한 부피세기조절회전치료 환자 별 정도관리의 유용성 평가)

  • Kang, Dong-Jin;Jung, Jae-Yong;Shin, Young-Joo;Min, Jung-Whan;Kim, Yon-Lae;Kwon, Kyung-Tae
    • Journal of radiological science and technology
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    • v.41 no.1
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    • pp.39-45
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    • 2018
  • The purpose of this study is to evaluate the usefulness of a software-based quality assurance system based on Volumetric Modulated Arc Therapy treatment plan. Evaluate treatment plan through the D VH analysis, PTV mean dose ($D_{mean}$) and PTV 95% dose($D_{95}$) compare the MFX based on original treatment plan, Average error rate was $0.9{\pm}0.6%$, $1.0{\pm}0.8%$, respectively. Measuring point dose using phantom and ion chamber, the average error rate between the ionization chamber and MFX was $0.9{\pm}0.7%$, $1.1{\pm}0.7%$ (high dose region), $1.1{\pm}0.9%$, $1.2{\pm}0.7%$ (low dose region). The average gamma though of MFX and $Delta^{4PT}$ is $98.7{\pm}1.2%$, $98.4{\pm}.3%$, respectively. Through this study, A software based QA system that simplifies hardware based QA procedures that involve a lot of time and effort. It can be used as a simple and useful tool in clinical practice.