In provisioning packet data service on wireless cellular networks, a sch.me of altering connection status between mobile and base stations appeared intending to efficiently utilize resource during idle periods. In suc...
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In provisioning packet data service on wireless cellular networks, a sch.me of altering connection status between mobile and base stations appeared intending to efficiently utilize resource during idle periods. In such a sch.me, connection components are sequentially released as an idle period persists, while the transmitting station converts to an transmission activity mode as the station is loaded with packets. However, actual resume of transmission activity is postponed by connection retrieval time to restore lost connection components. In general, an idle period affects the following connection retrieval time, which in turn produces an impact on the forthcoming idle period. Such chain reaction also makes a significant influence on overall packet delay performance. In this paper, as a way of improving packet delay performance, we propose two sch.mes identified as conservative extension and load threshold sch.mes. In the conservative extension sch.me, we intentionally extend connection retrieval times so that each connection retrieval time is guaranteed not to be lower than a certain value. On the other hand, according to the load threshold sch.me, a retrieval of lost connection components is postponed until packets are accumulated at the transmitting station up to a prescribed threshold. An increase in the value and threshold incurs an additional stand-by before resuming transmission activity in both proposed sch.mes. In turn, such intentional stand-by may contribute to regulating the length of idle period and connection retrieval time, and subsequently improving packet delay performance. To inspect the impact of conservative extension and load threshold sch.mes on packet delay performance, we first investigate the properties of idle periods. Secondly, for Poisson packet arrivals, we present an analytical method to exactly calculate the moments of packet delay time (at steady state) in each sch.me. From numerical examples, we confirm the existence of non-trivial
Transcoding is adopted to deliver video content to a broad range of end users with different preference and bandwidth constraints. Frame-skipping transcoding is one of the solutions to reduce the temporal resolution o...
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Transcoding is adopted to deliver video content to a broad range of end users with different preference and bandwidth constraints. Frame-skipping transcoding is one of the solutions to reduce the temporal resolution of the video sequence and decrease the overall bit rate. Traditionally used control sch.me in frame-skipping transcoding is based on buffer constraint or considers the motion activity of each frame. In this paper, we would like to propose a new frame-skipping control sch.me that considers the motion change and tries to reduce the jerky effect caused by the undesired frame skipping. Experiments show that proposed frame-skipping control sch.me can produce transcoded video look more like the original one and hence remain the visual quality.
In this paper, we suggest the method that uses compensated multiplicative parameter according to the local characteristic. Firstly we use a linear gain between original image and the halftone image to calculate the mu...
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ISBN:
(纸本)8955191197
In this paper, we suggest the method that uses compensated multiplicative parameter according to the local characteristic. Firstly we use a linear gain between original image and the halftone image to calculate the multiplicative parameters that minimize quantization error of flat region. We represent the edge region by compensating multiplicative parameters. The proposed method reduces quantization error that causes sharpening. The proposed method yields the halftone image which is similar to the original image and improved in quality.
In recent years the accurate detection of near-surface buried objects has attracted considerable attention from the remote sensing community. One of the more promising sensors for this problem is Ground Penetrating Ra...
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In recent years the accurate detection of near-surface buried objects has attracted considerable attention from the remote sensing community. One of the more promising sensors for this problem is Ground Penetrating Radar (GPR). This sensor has been applied to many problems including ore detection, locating pipes and conduits, waste remediation, landmine and unexploded ordnance detection, archaeologically surveying and non-destructive testing. Many algorithms exist which attempt to detect near-surface buried objects from GPR data. Some of these algorithms rely on expert interpretation of the collected data while others attempt to match the radar return to a database of known object returns. The ideal algorithm, however, will provide accurate images of the subsurface by reconstructing the elec.rical properties (permittivity and conductivity) of the buried scatterers and their ambient soil. Such an algorithm will provide the user with a three-dimensional image of the ground's permittivity and/or conductivity, from which objects may be easily identified. This review will focus upon algorithms which attempt to provide this ideal means of detection and will clearly identify how each algorithm differs from the ideal.
This paper presents an adaptive H. 263+ rate control algorithm for video streaming video applications under the networks supporting bandwidth renegotiation, which can communicate with end-users to accommodate their ti...
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This paper presents an adaptive H. 263+ rate control algorithm for video streaming video applications under the networks supporting bandwidth renegotiation, which can communicate with end-users to accommodate their time-varying bandwidth requests during the data transmission. That is, the requests of end-users can be supported adaptively according to the availability of the network resources, and thus the overall network utilization can be improved simultaneously. They are especially suitable for the transmission of non-stationary video traffics. The proposed rate control algorithm communicates with the network to renegotiate the required bandwidth for the underlying video which are measured based on the motion change information, and choose their control strategies according to the renegotiation results. Unlike most conventional algorithms that control only the spatial quality by adjusting quantization parameters, the proposed algorithm treats both the spatial and temporal qualities at the same time to enhance human visual perceptual quality. Experimental results are provided to demonstrate that the proposed rate control algorithm can achieve superior performance to the conventional ones with low computational complexity under the networks supporting bandwidth renegotiation.
This paper presents a fast direction of arrival (DOA) estimation algorithm that can rapidly estimate the incidence angles of signals using a pseudo covariance matrix even under coherent signal conditions. The conventi...
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This paper presents a fast direction of arrival (DOA) estimation algorithm that can rapidly estimate the incidence angles of signals using a pseudo covariance matrix even under coherent signal conditions. The conventional multiple signal classification (MUSIC) algorithm requires hundreds of snap-shots to produce a covariance matrix of signals, as such, it cannot perform a DOA estimation while acquiring this covariance matrix. In addition, the MUSIC algorithm cannot be used under rapidly changing or correlated signal conditions. In contrast, the proposed algorithm obtains the bearing response and directional spectrum after acquiring a pseudo covariance matrix for each snapshot. The incidence angles can then be exactly estimated by combining the bearing response and directional spectrum. Accordingly, unlike the MUSIC algorithm, since the proposed algorithm only uses a single snapshot to obtain the pseudo covariance matrix. It can rapidly estimate the DOAs of signals even when they are correlated.
Numerical optimization using recurrent Finite Difference Method (FDM) simulation is a promising direction in selec.ing power transmission line safe design. This article investigates the feasibility of elec.romagnetic ...
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Numerical optimization using recurrent Finite Difference Method (FDM) simulation is a promising direction in selec.ing power transmission line safe design. This article investigates the feasibility of elec.romagnetic field reduction by optimization of phase relationship in three-phase systems. Various transmission line phase positions are presented, which feature minimum elec.romagnetic effect on surface level. Different transmission line structure designs have been investigated in order to selec. the maximum phaser cancellation in three-phase systems. A deeper insight to the effects of changing the phase relocation has been presented, giving more understanding to the elec.romagnetic field reduction within the existing right-of-way. The primary objective of this ongoing project is to create rigorous methodology and software capable of solving elec.romagnetic field in three-phase systems, as well as solving various optimization problems in the field of elec.romagnetic field reduction for analysis and design of different phase locations. Examples of existing power lines and projects show practical applications.
In this paper, we present an attractive approach of argon plasma-induced quantum well intermixing for InP based heterostructures. The lattice-matched five quantum wells of InGaAs/InGaAsP grown by MOVPE exhibited a lar...
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The color reproduction error correction for color temperature conversion in plasma panel display (PDP) TV was discussed. The method was shown to be successfully coupled with flexible color temperature conversion based...
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The color reproduction error correction for color temperature conversion in plasma panel display (PDP) TV was discussed. The method was shown to be successfully coupled with flexible color temperature conversion based on the signal processing technique. The method can provide a range of color temperatures that are satisfactory for most viewers and can exactly reproduce color signals.
Optical sensors have been used in new technologies for detecting small amounts of chemical, gaseous species. In this work, new optical gas sensor used thin polymer layers was developed. We selec.ed polymer for gas sen...
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Optical sensors have been used in new technologies for detecting small amounts of chemical, gaseous species. In this work, new optical gas sensor used thin polymer layers was developed. We selec.ed polymer for gas sensing material. Polymers were synthesized and chemically polymerized by using the distilled aniline. The optical property of polymer as sensing materials was analyzed by using UV-Vis-NIR. These layers were prepared by using centrifugal force. The polymer layer was uniformly deposited inner glass pillar. The light source was red-LED with 655 nm wavelength. The light power transmitted through the guide cell was measured with a photodiode. The variation of light power transmitted was detected when the gas was absorbed in the polymer layer. The transmitted light intensity was decreased because gas molecules were absorbed into polymer layer. NH3gas is used as the evaluating gas. This optical sensor showed a good sensitivity to NH3gas.
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