• Title/Summary/Keyword: weighted average method

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Ecosysteme de I′Etang de Berre (Mediterranee nord-occidentale) : Caracteres Generales Physiques, Chimiques et Biologiques

  • Kim, Ki-Tai
    • Korean Journal of Environmental Biology
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    • v.22 no.2
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    • pp.247-258
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    • 2004
  • Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

Implementation of Wavelet Transform based Image Fusion and JPEG2000 using MAD Order Statistics for Multi-Image (MAD 순서통계량을 이용한 웨이블렛 변환기반 다중영상의 영상융합 및 JPEG2000 보드 구현)

  • Lee, Cheeol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.11
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    • pp.2636-2644
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    • 2013
  • This paper is proposed a wavelet-based the order statistics MAD(Median Absolute Deviation) method of image fusion of Multi-image contaminated with visible image and infrared image. also The method of compared and defined the threshold the wavelet coefficients using MAD of the wavelet coefficients of the detail subbands was proposed to effectively fusion which of selected the high quality image of the two images. The existed fusion rule may be possible to get the distorted fusion image especially by the distortion in the relation between the pixel and indicator of two images in the existed fusion rules. In order to complement the disadvantage, the threshold of the proposed method sets up the image statistic and excludes the distortion. The hardware design is used FPGA of Xilinx and DSP system for the image fusion and compressed encoding of the proposed algorithm. Therefore the proposed method is totally verified by comparing with the several other multi-image and the proposed image fusion.

Removal of Search Point using Motion Vector Correlation and Distance between Reference Frames in H.264/AVC (움직임 벡터의 상관도와 참조 화면의 거리를 이용한 H.264/AVC 움직임 탐색 지점 제거)

  • Moon, Ji-Hee;Choi, Jung-Ah;Ho, Yo-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.2A
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    • pp.113-118
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    • 2012
  • In this paper, we propose the removal of search point using motion vector correlation and distance between reference frames in H.264/AVC. We remove the search points in full search method and predictive motion vectors in enhanced predictive zonal search method. Since the probability that the reference frame far from the current frame is selected as the best reference frame is decreased, we apply the weighted average based on distance between the current and reference frame to determine the fianl search range. In general, the size of search range is smaller than initial search range. We reduce motion estimation time using the final search range in full search method. Also, the refinement process is adaptively applied to each reference frame. The proposed methods reduce the computational throughput of full search method by 57.13% and of enhanced predictive zonal search by 14.71% without visible performance degradation.

Fuzzy Neural Networks-Based Call Admission Control Using Possibility Distribution of Handoff Calls Dropping Rate for Wireless Networks (핸드오프 호 손실율 가능성 분포에 의한 무선망의 퍼지 신경망 호 수락제어)

  • Lee, Jin-Yi
    • Journal of Advanced Navigation Technology
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    • v.13 no.6
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    • pp.901-906
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    • 2009
  • This paper proposes a call admission control(CAC) method for wireless networks, which is based on the upper bound of a possibility distribution of handoff calls dropping rates. The possibility distribution is estimated in a fuzzy inference and a learning algorithm in neural network. The learning algorithm is considered for tuning the membership functions(then parts)of fuzzy rules for the inference. The fuzzy inference method is based on a weighted average of fuzzy sets. The proposed method can avoid estimating excessively large handoff calls dropping rates, and makes possibile self-compensation in real time for the case where the estimated values are smaller than real values. So this method makes secure CAC, thereby guaranteeing the allowed CDR. From simulation studies we show that the estimation performance for the upper bound of call dropping rate is good, and then handoff call dropping rates in CAC are able to be sustained below user's desired value.

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Low-complexity Local Illuminance Compensation for Bi-prediction mode (양방향 예측 모드를 위한 저복잡도 LIC 방법 연구)

  • Choi, Han Sol;Byeon, Joo Hyung;Bang, Gun;Sim, Dong Gyu
    • Journal of Broadcast Engineering
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    • v.24 no.3
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    • pp.463-471
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    • 2019
  • This paper proposes a method for reducing the complexity of LIC (Local Illuminance Compensation) for bi-directional inter prediction. The LIC performs local illumination compensation using neighboring reconstruction samples of the current block and the reference block to improve the accuracy of the inter prediction. Since the weight and offset required for local illumination compensation are calculated at both sides of the encoder and decoder using the reconstructed samples, there is an advantage that the coding efficiency is improved without signaling any information. Since the weight and the offset are obtained in the encoding prediction step and the decoding step, encoder and decoder complexity are increased. This paper proposes two methods for low complexity LIC. The first method is a method of applying illumination compensation with offset only in bi-directional prediction, and the second is a method of applying LIC after weighted average step of reference block obtained by bidirectional prediction. To evaluate the performance of the proposed method, BD-rate is compared with BMS-2.0.1 using B, C, and D classes of MPEG standard experimental image under RA (Random Access) condition. Experimental results show that the proposed method reduces the average of 0.29%, 0.23%, 0.04% for Y, U, and V in terms of BD-rate performance compared to BMS-2.0.1 and encoding/decoding time is almost same. Although the BD-rate was lost, the calculation complexity of the LIC was greatly reduced as the multiplication operation was removed and the addition operation was halved in the LIC parameter derivation process.

Perceptual and Adaptive Quantization of Line Spectral Frequency Parameters (선 스펙트럼 주파수의 청각 적응 부호화)

  • 한우진;김은경;오영환
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.8
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    • pp.68-77
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    • 2000
  • Line special frequency (LSF) parameters have been widely used in low bit-rate speech coding due to their efficiency for representing the short-time speech spectrum. In this paper, a new distance measure based on the masking properties of human ear is proposed for quantizing LSF parameters whereas most conventional quantization methods are based on the weighted Euclidean distance measure. The proposed method derives the perceptual distance measure from the definition of noise-to-mask ratio (NMR) which has high correspondence with the actual distortion received in the human ear and uses it for quantizing LSF parameters. In addition, we propose an adaptive bit allocation scheme, which allocates minimal bits to LSF parameters maintaining the perceptual transparency of given speech frame for reducing the average bit-rates. For the performance evaluation, we has shown the ratio of perceptually transparent frames and the corresponding average bit-rates for the conventional and proposed methods. By jointly combining the proposed distance measure and adaptive bit allocation scheme, the proposed system requires only 770 bps for obtaining 95.5% perceptually transparent frames, while the conventional systems produce 89.9% at even 1800 bps.

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EMG Signal Elimination Using Enhanced SVD Filter in Multi-Lead ECG (향상된 SVD 필터를 이용한 Multi-lead ECG에서의 EMG 신호 제거)

  • Park, Kwang-Li;Park, Se-Jin;Choi, Ho-Sun;Jeong, Kee-Sam;Lee, Kyoung-Joung;Yoon, Hyoung-Ro
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.6
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    • pp.302-308
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    • 2001
  • SVD(Singular Value Decomposition) filter for the suppression of EMG in multi-lead stress ECG is studied. SVD filter consists of two parts. In the first part, the basis vectors were chosen from the averaged singular vectors obtained from the decomposed noise-free ECG. The singular vector is computed from the stress ECG and is compared itself with basis vectors to know whether the noise exist in stress ECG. In the second part, the existing elimination method is used, when one(or two) channels is(or are) contaminated by noise. But the proposed enhanced SVD filter is used in case of having the noise in the many channels. During signal decomposition and reconstruction, the noise-free channel or the least noisy channel have the weight of 1, the next less noisy channel has the weight of 0.8. In this way, every channel was weighted by decreased of 0.2 in proportion to the amount of the added noise. For the evaluation of the proposed enhanced SVD filter, we compared the SNR computed by the enhanced SVD filter with the standard average filter for the noise-free signal added with artificial noise and the patient data. The proposed SVD filter showed better in the SNR than the standard average filter. In conclusion, we could find that the enhanced SVD filter is more proper in processing multi-lead stress ECG.

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An Efficient Test Pattern Generator for Low Power BIST (내장된 자체 테스트를 위한 저전력 테스트 패턴 생성기 구조)

  • Kim, Ki-Cheol;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.8
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    • pp.29-35
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    • 2010
  • In this paper we propose a new pattern generator for a BIST architecture that can reduce the power consumption during test application. The principle of the proposed method is to reconstruct an LFSR circuit to reduce WSAs of the heavy nodes by suppressing the heavy inputs. We propose algorithms for finding heavy nodes and heavy inputs. Using the Modified LFSR which consists of some AND/OR gates trees and an original LFSR, BIST applies modified test patterns to the circuit under test. The proposed BIST architecture with small hardware overhead effectively reduces the average power consumption during test application while achieving high fault coverage. Experimental results on the ISCAS benchmark circuits show that average power reduction can be achieved up to 30.5%.

A Study on the Construction of Historical Profiles for Travel Speed Prediction Using UTIS (UTIS기반 구간통행속도 예측을 위한 교통이력자료 구축에 관한 연구)

  • Ki, Yong-Kul;Ahn, Gye-Hyeong;Kim, Eun-Jeong;Bae, Kwang-Soo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.6
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    • pp.40-48
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    • 2012
  • In this paper, we suggests methods for determining optimal representative value and the optimal size of historical data for reliable travel speed prediction. To evaluate the performance of the proposed method in real world environments, we did field tests at four roadway links in Seoul on Tuesday and Sunday. According to the results of applying the methods to historical data of Central Traffic Information Center, the optimal representative value were analyzed to be average and weighted average. Second, it was analyzed that 2 months data is the optimal size of historical data used for travel speed prediction.

Evaluation of Video Codec AI-based Multiple tasks (인공지능 기반 멀티태스크를 위한 비디오 코덱의 성능평가 방법)

  • Kim, Shin;Lee, Yegi;Yoon, Kyoungro;Choo, Hyon-Gon;Lim, Hanshin;Seo, Jeongil
    • Journal of Broadcast Engineering
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    • v.27 no.3
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    • pp.273-282
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    • 2022
  • MPEG-VCM(Video Coding for Machine) aims to standardize video codec for machines. VCM provides data sets and anchors, which provide reference data for comparison, for several machine vision tasks including object detection, object segmentation, and object tracking. The evaluation template can be used to compare compression and machine vision task performance between anchor data and various proposed video codecs. However, performance comparison is carried out separately for each machine vision task, and information related to performance evaluation of multiple machine vision tasks on a single bitstream is not provided currently. In this paper, we propose a performance evaluation method of a video codec for AI-based multi-tasks. Based on bits per pixel (BPP), which is the measure of a single bitstream size, and mean average precision(mAP), which is the accuracy measure of each task, we define three criteria for multi-task performance evaluation such as arithmetic average, weighted average, and harmonic average, and to calculate the multi-tasks performance results based on the mAP values. In addition, as the dynamic range of mAP may very different from task to task, performance results for multi-tasks are calculated and evaluated based on the normalized mAP in order to prevent a problem that would be happened because of the dynamic range.