DYNAMIC BANDWIDTH ALLOCATION IN AN ATM MULTIPLEXER WITH MULTICLASS TRAFFIC AND ITS PERFORMANCE ANALYSIS

This paper introduces two source models: MAP(Markovian arrival process) model for the traffic with correlation and burst, e.g., voice, video, etc. and PAP(Poisson arrival process) model for the traffic with non-correlation, such as data, etc. Then a movable boundary bandwidth access policy is chosen.Basing on above model, the performance measures, e.g., mean waiting time and loss probability,especially the queue length time distribution are obtained. Finally, a number of numerical results are provided and shown through simulation.     

两不同部件串联可修系统的可用度的一个新的计算方法

本用直接解一组不含时间t的一阶线性偏微分积方程而得到两不同部件可修系统的可用度。     

双极工艺模拟的校正及其应用

介绍了双极工艺基区和发射区结构模拟所涉及的物理模型，包括与单种工艺有关的杂质分凝模型、硼的间隙扩散模型及高浓度磷扩散模型等。特别分析了与多步工艺有关的点缺陷模型及其模拟校正过程，最后给出了模型校正的应用。     

Chemical mechanical polishing of polycarbonate and poly methyl methacrylate substrates

In recent years, polymeric materials such as polycarbonate (PC) and poly methyl methacrylate (PMMA) are replacing silicon as major substrates in microfluidic system fabrication due to the outstanding features like low cost and good chemical resistance. In this study, chemical mechanical polishing (CMP) of PC and PMMA substrates was investigated. First, four types of slurry were tested. Then, the slurry producing relatively high material removal rate (MRR) and low surface roughness was chosen, and experiments were designed and carried out to investigate the effects of key process parameters. The experimental results show impacts of key CMP process parameters on MRR and surface finish of PC and PMMA substrates. An increase in head load or table speed would cause an increase in surface roughness heights and MRR. The surface quality of the polymers after CMP appeared to be acceptable for most of microelectromechanical system applications as the process conditions were restrained within the process window.     

Hydrodynamic cavitation-assisted preparation of porous carbon from garlic peels for supercapacitors

Hydrodynamic cavitation (HC), which can effectively induce sonochemical effects, is widely considered a promising process intensification technology. In the present study, HC was successfully utilized to intensify the alkali activation of GPs for SCs, for the first time. Five BDCMs were synthesized following the method reported in the literature. For comparison, four more BDCMs with HC-treated, among which a sample was further doped with nitrogen during the HC treatment, were prepared. Then all the samples were compared from microscopical characteristics to electrochemical performance as SCs materials. The morphology study demonstrated that the HC treatment had created many defects and amorphous carbon structures on the GP-based BDCMs, with the highest SSA reaching 3272 m²/g (1:6-HCGP), which 32 folded that of the Raw carbon sample’s. The HC treatment also intensified the N-doping process. XRD and XPS results manifested that the N content had been increased and consequently changed the electronic structure of the carbon atoms, leading to the increase of specific capacitance (1:6-HCGP+N-based SC, 227 F/g at 10 A/g). The cycle performance proved that the GP-based BDCMs have long-term stability, indicating that the HC-treated BDCMs were good choices for energy storage technologies. Compared with the ultrasound-assisted method, which may have a high energy density, the HC-assisted method enables high production and energy efficiency. This work is a first time attempt towards the industrial application of HC method in energy-related materials synthesis and encourages more in-depth studies in the future.     

Sustainable extraction of ligustilide and ferulic acid from Angelicae Sinensis Radix,for antioxidant and anti-inflammatory activities

The 2030 Agenda for Sustainable Development envisions a rational use of energy and resources in all technological processes. However, in the extraction methods of compounds from medicinal plants and herbs, there is an urgent to reduce the use of organic solvents and increase the energy efficiency of these methods. Therefore, a sustainable extraction method (enzyme and ultrasonic co-assisted aqueous two-phase extraction, EUA-ATPE) of simultaneous extraction and separation of ferulic acid and ligustilide from Angelicae Sinensis Radix (ASR) was developed by integrating enzyme-assisted extraction (EAE) with ultrasonic-assisted aqueous two-phase extraction (UAE- ATPE). The effects of different enzymes, extraction temperature, pH, ultrasonic time, liquid-to-materials ratio, etc., were optimized by single-factor experiments and central composite design (CCD). Under the optimum conditions, the highest comprehensive evaluation value (CEV) and extraction yield were obtained by EUA-ATPE. Furthermore, recovery (R), partition coefficient (K), and scanning electron microscopy (SEM) analysis revealed that enzyme and ultrasonic treatment improved mass transfer diffusion and increased the degree of cell disruption. Besides, the EUA-ATPE extracts have shown great antioxidant and anti-inflammatory activity in vitro. Finally, compared to different extraction methods, EUA-ATPE achieved higher extraction efficiency and higher energy efficiency due to the synergistic effect between EAE and UAE-ATPE. Therefore, the EUA-ATPE provides a sustainable method for extracting bioactive compounds from medicinal plants and herbs, contributing to Sustainable Development Goals (SDG), including SDG-6, SDG-7, SDG-9, SDG-12, and SDG-15.     

Degradation of benzene present in wastewater using hydrodynamic cavitation in combination with air

The degradation of benzene present in wastewater using hydrodynamic cavitation (HC) alone as well as in combination with air has been studied using nozzles as cavitating device of HC reactor. Initially, the energy efficiency of the HC reactor operated at different inlet pressures was determined using the calorimetric studies. Maximum energy efficiency of 53.4% was obtained at an inlet pressure of 3.9 bar. The treatment processes were compared under adiabatic as well as isothermal conditions and it was observed that under the adiabatic condition, the extent of degradation is higher as compared to isothermal condition. Studies related to the understanding the effect of inlet pressure (range of 1.8–3.9 bar) revealed that the maximum degradation as 98.9% was obtained at 2.4 bar pressure using the individual operation of HC under adiabatic conditions and in 70 min of treatment. The combination of HC with air was investigated at different air flow rates with best results for maximum degradation of benzene achieved at air flow rate of 60 mL/sec. A novel approach of using cavitation for a limited fraction of total treatment time was also demonstrated to be beneficial in terms of the extent of degradation as well as energy requirements and cost of operation. Based on the cavitational intensity, the resonant radius of aggregates of cavitation bubbles was also determined for distilled water as well as for aqueous solution of benzene. Overall, significant benefits of using HC combined with air have been demonstrated for degradation of benzene along with fundamental understanding into cavitation effects.     

Process corner detection by skew inverters for 500 MHZ 2×VDD output buffer using 40-nm CMOS technology

A PVT detection and compensation technique is proposed to automatically adjust the slew rate of a high-speed 2×VDD output buffer. Based on the detected PVT (Process, Voltage, Temperature) corner, the output buffer will turn on different current paths correspondingly to either increase or decrease the output driving current such that the slew rate of the output signal is adaptive. The proposed design is implemented using a typical 40 nm CMOS process to justify the slew rate compensation performance. By on-silicon measurements, the data rate is 500/460 MHz given 0.9/1.8 V supply voltage with a 20 pF load. Particularly, the maximum slew rate improvement is 8%, the core area of the proposed design is 0.052×0.254 mm², the maximum slew rate is 0.53 (V/ns), and the area overhead is only 31% for one single output buffer.     

结构可靠性优化的多输出高斯过程代理模型

对于具有多失效模式的结构,基于可靠性的结构优化计算成本是比较昂贵的。本文利用多输出高斯过程MOGP(Multiple Output Gaussian Process)代理模型以降低计算成本,首先利用Bucher方法生成初始样本,然后结合均匀训练样本和学习函数对MOGP代理模型进行构建。学习函数可在大范围内筛选出较为满意的训练样本,能够确保MOGP代理模型具有较好的全局精度,在整个优化过程中不再重新构建MOGP代理模型。利用协方差矩阵,MOGP代理模型能够考虑各失效模式的相关性,对多输入多输出系统具有良好的预测性能。数值算例表明,本文方法具有较好的计算结果,且计算效率较高,尤其是设计变量数目与失效模式数目较多时效率提升明显。     

Pre-Envelope Covariance Differential Equations For White and Nonwhite Input Processes

The pre-envelope process is a complex process whose statistics are strictly related to the statistics of the envelope of a given process. The paper deals with the evaluation of the covariances of the pre-envelope output process of classically and nonclassically damped linear systems subjected to stationary and nonstationary white and nonwhite pre-envelope input process. More precisely, the pre-envelope covariances for nonwhite complex input processes are evaluated as solution of a set of first order differential equations. Furthermore, in the paper the pre-envelope of the white input process is defined, and for such input the pre-envelope covariance differential equations are determined by means of an extension to the complex field of the stochastic differential calculus. Sommario.Il processo 'pre-inviluppo' é un processo complesso i cui parametri statistici sono strettamente legati a quelli del processo 'inviluppo'. Il lavoro riguarda la valutazione delle covarianze del processo pre–inviluppo della risposta di sistemi dinamici classicamente e non classicamente smorzati soggetti a processi pre–inviluppo bianchi e filtrati, stazionari e non stazionari. Piprecisamente, nel caso di un processo filtrato pre–inviluppo le covarianze della risposta sono valutate come soluzione di un sistema di equazioni differenziali del primo ordine. Inoltre, nel lavoro definito il processo pre–inviluppo di un processo bianco e per tale caso sono presentate le equazioni differenziali delle covarianze della risposta ottenute attraverso l'estensione al campo complesso del classico calcolo differenziale stocastico.