首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
HVMDM:      
《计算机工程》2000,26(3):11-12
  相似文献   

2.
Journal of Real-Time Image Processing - This work presents a novel color correction algorithm between images (or image regions) depicting the same environment. Color transfer is achieved by a...  相似文献   

3.

This research article presents and describes a novel design with improved performance low power consumption threshold voltage based CMOS thermal sensor for aerospace applications. The proposed temperature sensor utilizes the change in behavior of threshold voltage of MOSFET with variation in temperature. The challenge while designing the temperature sensor was to achieve the linearize output voltage with respect to change in temperature. Process corner analysis has been done to check the robustness of the circuit while performance analysis and sensitivity of the temperature sensor have been verified in the occurrence of parasitic. The proposed temperature sensor is featured with low power consumption, less power supply voltage utilization, high performance and sensitivity with inaccuracy as low as possible. The presented temperature sensor utilizes an active area of 18 µm × 9.85 µm with 117 nW power consumption. An improved linear performance with an inaccuracy of merely − 0.01 to + 0.47 °C over a wide temperature range of − 20 to + 120 °C is presented here. The sensitivity of proposed temperature sensor is found to be as high as 0.77 mV/°C. The proposed temperature sensor is realized and tested in Cadence virtuoso mixed signal design atmosphere using 0.18 µm CMOS technology and further investigated with support of tool from Mentor graphics. The engaged area of pad-limited chip is measured to be 0.96 mm2.

  相似文献   

4.
Microsystem Technologies - In this work, the design and power consumption analysis of NOR based 4 × 4 semiconductor read-only-memory (ROM) array has been presented. In this...  相似文献   

5.
Recommender Systems are the set of tools and techniques to provide useful recommendations and suggestions to the users to help them in the decision-making process for choosing the right products or services. The recommender systems tailored to leverage contextual information (such as location, time, companion or such) in the recommendation process are called context-aware recommender systems. This paper presents a review on the continual development of context-aware recommender systems by analyzing different kinds of contexts without limiting to any specific application domain. First, an in-depth analysis is conducted on different recommendation algorithms used in context-aware recommender systems. Then this information is used to find out that how these techniques deals with the curse of dimensionality, which is an inherent issue in such systems. Since contexts are primarily based on users’ activity patterns that leads to the development of personalized recommendation services for the users. Thus, this paper also presents a review on how this contextual information is represented (either explicitly or implicitly) in the recommendation process. We also presented a list of datasets and evaluation metrics used in the setting of CARS. We tried to highlight that how algorithmic approaches used in CARS differ from those of conventional RS. In that, we presented what modification or additions are being applied on the top of conventional recommendation approaches to produce context-aware recommendations. Finally, the outstanding challenges and research opportunities are presented in front of the research community for analysis  相似文献   

6.
LCV模型在医学图像分割中的应用     总被引:1,自引:0,他引:1  
杨勇  马志明  徐春 《计算机工程》2010,36(10):184-186
针对C-V模型不能充分利用图像局部区域灰度变化信息从而导致难以准确分割灰度不均物体等缺陷,提出一种基于局部区域的C-V(LCV)模型。利用计算局部窗函数内的加权灰度均值来取代全局均值,并加入约束水平集函数为符号距离函数的能量项,从而避免水平集函数的重新初始化。对医学图像的分割结果证明LCV模型在分割灰度不均物体方面优于C-V模型,其分割效率高于LBF模型。  相似文献   

7.
8.
Gröbner bases of ideals of polynomials are known to have many applications. They have been applied to problems in commutative algebra, statistics, graph theory, robotics and differential equations. Their use as a research tool, however, is limited by their computational complexity. These two facts have inspired numerous attempts to parallelize Buchberger's algorithm to compute them.In this paper, we describe a parallel implementation developed on the Cray T3D using the extensions to C provided by ac. The program is based on the publicly available package Macaulay which computes Gröbner bases of homogeneous ideals overZpfor primesp   31991. The efficiency is nearly 100% on up to 16 processors for moderately sized problems. Above 16 processors, the efficiency drops.  相似文献   

9.
Given the recent trend in Data Science (DS) and Sports Analytics, an opportunity has arisen for utilizing Machine Learning (ML) and Data Mining (DM) techniques in sports. This paper reviews background and advanced basketball metrics used in National Basketball Association (NBA) and Euroleague games. The purpose of this paper is to benchmark existing performance analytics used in the literature for evaluating teams and players. Basketball is a sport that requires full set enumeration of parameters in order to understand the game in depth and analyze the strategy and decisions by minimizing unpredictability. This research provides valuable information for team and player performance basketball analytics to be used for better understanding of the game. Furthermore, these analytics can be used for team composition, athlete career improvement and assessing how this could be materialized for future predictions. Hence, critical analysis of these metrics are valuable tools for domain experts and decision makers to understand the strengths and weaknesses in the game, to better evaluate opponent teams, to see how to optimize performance indicators, to use them for team and player forecasting and finally to make better choices for team composition.  相似文献   

10.
The Job-Shop Scheduling Problem (JSSP) is well known for its complexity as an NP-hard disjunctive scheduling problem. The problem addressed in this paper is JSSPs with an objective of minimizing makespan while satisfying a number of hard constraints. An efficient GRASP × ELS approach is introduced for solving this problem. The efficiency is evaluated using the widely known 40 Laurence’s instances which encompass medium and large scale instances. The computational results prove that the proposed method competes with the best published methods in both quality of results and computational time. Recently, Web services have generated great interest in researchers. Such application architecture is based on the client–server model using existing Internet protocols and open standards. It provides new approaches to optimization methods. The proposed GRASP × ELS is packaged into a Web Service (WS), i.e., it offers for the research community an open access to our optimization approach. Moreover, the proposed web service can be even included in research future works with a very small programming effort.To favor utilization of the web service and to prove the facility in which the service could be used, we provide an example in Java proving that it is possible to obtain in less than 10 min a client application using the different methods exposed by this web service. Such usage extends to classical library inclusion in program with the difference that a method is called in the client side and represents an execution on the server.The Web Service paradigm is a new approach in spreading algorithms and therefore this paper stands at the crossroads of optimization research community and the web service community expectations. The GRASP × ELS provided in the web service, is a state of the art method which competes with previously published ones and which has the advantage of being available for free, in any languages, everywhere contributing in spreading operational research contribution.  相似文献   

11.
Complete phase diagrams for the poly ethylene glycol di-methyl ether 2000 (PEGDME2000)+Na3PO4+H2O system at TT = (298.15, 308.15 and 318.15) K were determined. Liquid–liquid equilibria (LLE) for the aqueous PEGDME2000+Na3PO4 system were determined experimentally at TT = (298.15, 308.15, 313.15 and 318.15) K. The effects of temperature on the binodals and tie-lines of the investigated aqueous two-phase system (ATPS) were also studied. Furthermore, the modified local composition segment-based NRTL and Wilson models and also osmotic virial equation were used for the correlation and prediction of the liquid–liquid phase behavior of the studied system.  相似文献   

12.
Binodal data for 2-propanol + potassium/sodium carbonate + water systems and ethanol + sodium carbonate + water system were experimentally determined at 298.15 K, and the phase diagram was plotted. Three empirical equations were used to correlate binodal data. Base on the proposed equation with highest accuracy and lever rule, the phase equilibrium compositions for 2-propanol + potassium/sodium carbonate + water system were directly calculated by MATLAB. The Othmer–Tobias equation and the Bancroft equation were used to correlate tie-line data. The results indicate that the calculation method and corresponding tie-line data are reliable. The effect of salts on phase-separation was discussed. Salting-out coefficient and effective excluded volume of potassium carbonate and sodium carbonate in 2-propanol–water component solvent were calculated to evaluate the salting-out ability of salts. An effective excluded volume of sodium carbonate in ethanol/2-propanol–water component solvents was used to evaluate the phase-separation ability of investigated alcohols. Based on the experimental and calculated results, it can be concluded that sodium carbonate shows a higher salting-out ability than potassium carbonate and 2-propanol is easier to be excluded to the alcohol-rich phase than ethanol.  相似文献   

13.
Plant species discrimination using remote sensing is generally limited by the similarity of their reflectance spectra in the visible, NIR and SWIR domains. Laboratory measured emissivity spectra in the mid infrared (MIR; 2.5 μm–6 μm) and the thermal infrared (TIR; 8 μm–14 μm) domain of different plant species, however, reveal significant differences. It is anticipated that with the advances in airborne and space borne hyperspectral thermal sensors, differentiation between plant species may improve. The laboratory emissivity spectra of thirteen common broad leaved species, comprising 3024 spectral bands in the MIR and TIR, were analyzed. For each wavelength the differences between the species were tested for significance using the one way analysis of variance (ANOVA) with the post-hoc Tukey HSD test. The emissivity spectra of the analyzed species were found to be statistically different at various wavebands. Subsequently, six spectral bands were selected (based on the histogram of separable pairs of species for each waveband) to quantify the separability between each species pair based on the Jefferies Matusita (JM) distance. Out of 78 combinations, 76 pairs had a significantly different JM distance. This means that careful selection of hyperspectral bands in the MIR and TIR (2.5 μm–14 μm) results in reliable species discrimination.  相似文献   

14.

A new external current sensing circuit with baseline compensation for the active matrix organic light emitting diode (AMOLED) display is developed herein to achieve the sensing precision of 0.5 nA in pixel with 7 µs of settling time. Current sensing circuit incorporates a new push–pull transient current feedforward whereas the current analog to digital converter (CADC) based digital baseline current compensation incorporates an 11-bit current digital-to-analog converter, a current comparator and a digital control circuit with an 11-bit successive approximation register. The proposed integrated mixed signal IC drives a 6T1C pixel-based AMOLED panel with one horizontal time of 7.7 µs at a scan frequency of 60 Hz. The design readout chip can simultaneously sense and compensate TFT baseline current variation. The readout circuit and the baseline compensation circuit are implemented in the integrated chip with chip area of 125 μm × 46 μm and fabricated via TSMC T18 process. With the standard 3.3 V supply, experimental result shows that the overall power consumption of the chip is 988 µW watt. The minimum LSB current for the CADC is 10 nA and the maximum achievable sampling rate is 500 KS/s. The measured INL and DNL of CADC is 0.84 and 0.98 respectively. Despite of heavy data line parasitic capacitances (2.6 KΩ/20 pF) of the AMOLED display, experimental results show that the proposed circuit can sense 0.5 nA current within 7 µs of settling time. The sensing precision of 0.5 nA within 7 µs are the best among all reported literature to date whereas the current sense range (0.5–500 nA), system sampling rate (142 KS/s), INL (0.84) and DNL (0.98) of the CADC is approximately comparable among all reported.

  相似文献   

15.
Based on the ab-initio calculations the thermodynamics of the Sb2Se3 intermediate phase was modeled and used in the calculations of the Sb–Se phase diagram together with the thermodynamic properties of liquid phase elaborated by the association model. The modeled heat capacity of Sb2Se3 phase shows excellent agreement with the experiment data available in the literature in the wide temperature range. The calculated equilibrium lines of the Sb–Se phase diagram good correlate with the experimental ones. The determined thermodynamic parameters can be applied in future calculations of the high-ordered systems and for determination of the Sb2Se3 thermoelectric properties.  相似文献   

16.
17.
The phase equilibria of the Mg–Sn-Nd ternary at 400 °C were investigated by X-ray powder diffraction (XRD), scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS). Seven stable ternary compounds and one eutectoid decomposed structure (A1) were observed in the section. The crystal structure for the phases: τ1 (MgSnNd, I4/mmm, tI12) and τ2 (MgSn2Nd, I42 m, tI32) were confirmed. τ3 (Mg75Sn3.5Nd21.5) is the iso-structure of Mg23SnLa6 (Zn23SiZr6 prototype, cF120 Pearson's code) and τ4 (Mg40+3Sn26.7-3Nd33.3) has the same structure and homogeneity range of Mg4-xSn2+xLa3(0.12 < x ≤ 0.4) (Cu4Si2Zr3 prototype, hP9 Pearson's code). The crystal structure of τ5 (Mg44Sn34Nd22), τ6 (Mg40Sn36Nd24) and τ7 (Mg16+3Sn45Nd39-3) are not determined. Two binary compounds Nd3Sn and Nd2Sn3, which were not included in the Nd–Sn binary phase diagram, were detected in this work. All detected Nd–Sn binary compounds show different amounts of Mg solubility, among which NdSn3 and Nd5Sn4 dissolve up to 10 and 6.8 at.% Mg and the rest Nd–Sn binary phases contain 1–3 at.% Mg. The MgNd phase dissolves up to 6.0 at. % Sn.  相似文献   

18.

An energy efficient complementary metal-oxide-semiconductor (CMOS) temperature sensor and signal conditioning circuit with auto zeroing technique has been enunciated in this paper. In the present study, a novel CMOS temperature sensor based on sub-threshold MOS operation has been presented, which is designed for Aerospace applications. The proposed sensor does not use bipolar junction transistor (BJT) for sensing; instead it utilizes the temperature dependency of the threshold voltage of MOSFET. The proposed temperature sensor is designed to sense −30 to 150 °C and its sensitivity is 1.4 mV/°C while the power consumption is 60 nW. The accuracy of sensor is mainly limited by offset and flicker noise (1/f) noise, which is cancel by the autozeroing circuit with the help of switch capacitor circuit. The sensor circuit is designed with biasing sub circuit for controlling the curvature correction. The proposed temperature sensor and signal conditioning are simulated in a Cadence Analog Design Environment with UMC90 nm library. The simulation result shows an inaccuracy of −1/+0.7 °C.

  相似文献   

19.
The composition ranges of the phases in the pseudo binary system MgO-V2O3 were studied between 1661 and 1873 K and at controlled oxygen partial pressures of (3.55 ± 0.2) × 10-6 and (3.55 ± 0.3) × 10-5 Pa. The phase relationship was determined by equilibrating MgO-V2O3 pellets in a CO-CO2 mixture followed by quenching and electron-probe microanalysis. To ensure sufficient quenching, a new setup was designed and developed, so that the equilibrated samples can be quenched in oil directly under the same atmosphere inside the experimental setup. Three different phases were found in the samples, namely MgO, MgO-V2O3 spinel and V2O3. The phase boundaries were determined with good reproducibility. The solubility of V2O3 in the MgO phase increased with temperature and was significantly higher than literature data. The spinel as well as the V2O3 composition range were found to change only a little with temperature in the investigated temperature range. Decreased oxygen potential led to a slight increase of the V2O3 content in the spinel phase and V2O3 phase. Furthermore, decreased oxygen potential resulted in a significant increase of the solubility of V2O3 in the MgO phase at the higher temperatures, especially at 1873 K.  相似文献   

20.
The isothermal section of the La–Si–Mg system at 500 °C was constructed in the whole concentration range by means of the SEM-EDXS and XRPD characterization of about forty alloys prepared by induction melting and then annealed. Phase equilibria are characterized by the following ternary phases: τ1-La2+xSi2Mg1−x (0≤x≤0.35,tP10-Mo2FeB2), τ2-LaSi2Mg2 (tP5-CeSi2Mg2), τ3-LaSi2Mg (structure still unknown) and τ4-La6SiMg23 (cF120-Zr6SiZn23). The high temperature binary phase LaMg2 (cF24-MgCu2) has been found to be stabilized at 500 °C probably by a small amount of Si. Phases in binary subsystems do not generally form extended ternary solid solutions except for (La1−xMgx)3Si2 (0≤x≤0.167,tP10-U3Si2). Crystal structures of phases τ1-La2+xSi2Mg1−x and (La1−xMgx)3Si2 are correlated, the former being a substitution derivative of the latter.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号