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1.
An analytical model is presented to study the dynamics of wavelength division multiplexing (WDM) networks with waveband switching (WBS). The reduced load approximation method is considered to compute approximated network blocking probabilities in WBS-based WDM networks. The analytical model considers the link blocking probability due to insufficient link capacity and an impact of the waveband granularity (G). The analytical model also considers the node blocking probability due to unavailability of a switch port at the wavelength cross connect (WXC) layer of an Hierarchical cross connect (HXC) switch node. The set of nonlinear equations is obtained with the link independence assumption and solved using repeated substitutions. The accuracy of the analytical model is examined by comparing with simulation results considering the random-fit algorithm for waveband and wavelength assignments in different network scenarios. Lightpaths are routed between source and destination (s-d) HXC switch nodes using shortest path first (SPF) routing. An impact of the switch parameter to limit the input and the output WXC switch ports of an HXC switching node is also being investigated using the analytical model as well as through simulation results. 相似文献
2.
为了延缓埋地煤气管道腐蚀速度,延长管道使用寿命,用科学的手段分析了堵塞物的主要成分,分析了堵塞物的形成原因,主要是由于所输送的煤气中大量杂质的存在,有针对性地提出了防范措施,以减少堵塞物的形成. 相似文献
3.
V型选粉机是水泥厂粉磨系统中重要的选粉设备,研究其内部气固两相流动规律对提升粉磨系统性能具有重要意义。采用计算颗粒流体力学(Computational Particle Fluid Dynamics, CPFD)方法对V型选粉机内部颗粒运动轨迹和流场信息进行数值模拟分析,对比两种型号的选粉机以及其阀门全开和阀门全关两种工况下的气固流动特征。结果表明:关闭阀门时,选粉机选粉效率增大,阻力也增大;型号Ⅰ选粉机的进风口和布风区,以及型号Ⅱ选粉机的进料口都有优化改进的空间。研究结果可为后续V型选粉机的设备选型、结构和工况优化提供参考依据。 相似文献
4.
Synthetic approaches for optimizing polymer-based organic photodiodes (OPDs) by systematically analyzing the effects of the hole-blocking layer, the electron-blocking layer, and the thickness and morphology of the active layer with respect to the dark current and detectivity have been reported. PBDTT-DPP with a repeating alkylthienylbenzodithiophene (BDTT) and diketopyrrolopyrrole (DPP) units is used as a p-type polymer for achieving both broadband absorption and a high absorption coefficient in conjunction with n-type [6,6]-phenyl C70 butyric acid methyl ester (PC70BM) for constructing photoactive layers. Through systematic investigations of various interfacial layers, we found that the thickness of the active layer and the energy level of the hole/electron blocking layer were critical for minimizing the dark current of OPDs. By changing the deposition method of the PBDTT-DPP/PC70BM blend and using post treatment, we discovered that the morphology of the active layer was directly related to the photocurrent of OPDs. Furthermore, we conducted a comparative study between a bulk heterojunction and a planar heterojunction (PHJ) to demonstrate the effectiveness of the PHJ for suppressing the dark current. Consequently, we realized a high detectivity of 5.3 × 1012 Jones with an optimized device architecture and morphology. This work shows the importance of a synthetic approach for optimizing OPDs that requires both a high photocurrent and a low dark current in the reverse saturation regime. 相似文献
5.
In this work we present a multi-source uncertain entity resolution model and show its implementation in a use case of Yad Vashem, the central repository of Holocaust-era information. The Yad Vashem dataset is unique with respect to classic entity resolution, by virtue of being both massively multi-source and by requiring multi-level entity resolution. With today's abundance of information sources, this project motivates the use of multi-source resolution on a big-data scale. We instantiate the proposed model using the MFIBlocks entity resolution algorithm and a machine learning approach, based upon decision trees to transform soft clusters into ranked clustering of records, representing possible entities. An extensive empirical evaluation demonstrates the unique properties of this dataset that make it a good candidate for multi-source entity resolution. We conclude with proposing avenues for future research in this realm. 相似文献
6.
Effective approximations are developed for the blocking probability in a general stationary loss model, where key independence and exponential-distribution assumptions are relaxed, giving special attention to dependence among successive service times, not studied before. The new approximations exploit recent heavy-traffic limits for the steady-state number of busy servers in the associated infinite-server model with the same arrival and service processes. In addition, a new heavy-traffic approximation is developed for the long-run proportion of time that all servers are busy. These new approximations are then combined to develop new approximations for the separate blocking probabilities of individual arrival streams in multi-class loss models. Simulation experiments show that these approximations are effective. 相似文献
7.
8.
介绍KDN-18000型空分设备板翅式换热器空气通道堵塞的现象.详细叙述故障原因的分析和查找过程,介绍故障处理方法和经验教训。 相似文献
9.
An integrated low-cost adsorption (with powdered activated carbon, PAC) and cross-flow membrane filtration (with microfiltration membranes of 0.1 and 0.2 μm pore sizes) process was employed for the treatment of biotreated palm oil mill effluent (POME) to produce irrigation water that is fully benchmarked with water-quality standards. The permeate quality was within the recommended standard for irrigation water, as the concentrations of all critical constituents were well below their recommended values. Sustainability of the process integration was further confirmed with the domination of cake filtration over other blocking mechanisms with higher R2 values at all trans-membrane pressures. Suitable extended usage of permeate was found for toilet/urinal flushing. 相似文献
10.