A decoupling strategy for protecting sensitive process information in cooperative optimization of power flow

Optimal power flow (OPF) with close cooperation between the power grid and flexible electricity-intensive chemical processes can reduce costs for the grid and for electricity users. However, this would require sharing detailed chemical process models, which may reveal confidential information and potentially jeopardize competitive advantages for a chemical process operator. We propose an algorithm that enables economically advantageous cooperation without the need to exchange sensitive information. Low-order linear models are used to represent the dynamic behavior of electricity-intensive processes. We integrate these models into the OPF problem and solve the problem using a decoupling strategy based on Benders-type cuts. The cuts introduce limited communication between the chemical processes and the grid without exchanging explicit information pertaining to the process dynamics and performance. Our results reproduce solutions obtained by sharing detailed process models up to a user-defined optimality gap for several test cases that reflect both normal and congested grid states. We also investigate the trade-off between the value of the optimality gap and computational effort. Finally, we study the scaling behavior of the iterative procedure with respect to flexible loads at multiple grid locations.     

支持协同式AI问题求解的分布式成员系统模型

本文在分析了接近于人类思维方式的产生式系统基础上，提出了一种基于人类思维过程的有限关联团块的观点，并在此观点之上设计了一种支持协同式ＡＩ问题，求解分布式成员系统模型。     

大型三维复杂构件双机器人协同焊接智能路径规划方法

大型三维复杂构件是船舶、海洋装备、集装箱等的重要组成部分,其焊缝种类较多、空间分布复杂,部分焊缝存在协同同步弧焊焊接、焊接方向等特殊焊接工艺约束,现有协同焊接规划方法难适用于这类复杂场景。提出全局与局部相结合的双机器人协同焊接路径规划多阶段寻优方法;建立复杂构件三维空间焊缝模型以及双焊接机器人协同模型;根据协同同步焊焊缝的数量将构件划分出相应数量的分块,通过蚁群算法求解每一焊接分块的局部路径规划近似最优解;通过遗传粒子群算法进行多分块间的全局路径规划。仿真结果表明:通过分块划分多阶段寻优的方法可以有效地解决特殊焊接工艺约束下的大型三维复杂构件双机器人同步焊接路径规划问题。     

Cooperative, heparan sulfate-dependent cellular uptake of dimeric guanidinoglycosides

Oligoarginine and guanidinium-rich molecular transporters have been shown to facilitate the intracellular delivery of a diverse range of biologically relevant cargos. Several such transporters have been suggested to interact with cell-surface heparan sulfate proteoglycans as part of their cell-entry pathway. Unlike for other guanidinium-rich transporters, the cellular uptake of guanidinoglycosides at nanomolar concentrations is exclusively heparan sulfate dependent. As distinct cells differ in their expression levels and/or the composition of cell-surface heparan sulfate proteoglycans, one might be able to exploit such differences to selectively target certain cell types. To systematically investigate the nature of their cell-surface interactions, monomeric and dimeric guanidinoglycosides were synthesized by using neomycin, paromomycin, and tobramycin as scaffolds. These transporters differ in the number and 3D arrangement of their guanidinium groups. Their cellular uptake was measured by flow cytometry in wild-type and mutant Chinese hamster ovary cells after the corresponding fluorescent streptavidin-phycoerythrin-Cy5 conjugates had been generated. All derivatives showed negligible uptake in mutant cells lacking heparan sulfate. Decreasing the number of guanidinium groups diminished uptake, but the three dimensional arrangement of these groups was less important for cellular delivery. Whereas conjugates prepared with the monomeric carriers showed significantly reduced uptake in mutant cells expressing heparan sulfate chains with altered patterns of sulfation, conjugates prepared with the dimeric guanidinoglycosides could overcome this deficiency and maintain high levels of uptake in such deficient cells. This finding suggests that cellular uptake depends on the valency of the transporter and both the content and arrangement of the sulfate groups on the cell-surface receptors. Competition studies with chemically desulfated or carboxy-reduced heparin derivatives corroborated these observations. Taken together, these findings show that increasing the valency of the transporters retains heparan sulfate specificity and provides reagents that could distinguish different cell types based on the specific composition of their cell-surface heparan sulfate proteoglycans.     

Combustion of n-butanol in a spark-ignition IC engine

Alcohols, because of their potential to be produced from renewable sources and because of their high quality characteristics for spark-ignition (SI) engines, are considered quality fuels which can be blended with fossil-based gasoline for use in internal combustion engines. They enable the transformation of our energy basis in transportation to reduce dependence on fossil fuels as an energy source for vehicles. The research presented in this work is focused on applying n-butanol as a blending agent additive to gasoline to reduce the fossil part in the fuel mixture and in this way to reduce life cycle CO₂ emissions. The impact on combustion processes in a spark-ignited internal combustion engine is also detailed. Blends of n-butanol to gasoline with ratios of 0%, 20%, and 60% in addition to near n-butanol have been studied in a single cylinder cooperative fuels research engine (CFR) SI engine with variable compression ratio manufactured by Waukesha Engine Company. The engine is modified to provide air control and port fuel injection. Engine control and monitoring was performed using a target-based rapid-prototyping system with electronic sensors and actuators installed on the engine [1]. A real-time combustion analysis system was applied for data acquisition and online analysis of combustion quantities. Tests were performed under stoichiometric air-to-fuel ratios, fixed engine torque, and compression ratios of 8:1 and 10:1 with spark timing sweeps from 18° to 4° before top dead center (BTDC). On the basis of the experimental data, combustion characteristics for these fuels have been determined as follows: mass fraction burned (MFB) profile, rate of MFB, combustion duration and location of 50% MFB. Analysis of these data gives conclusions about combustion phasing for optimal spark timing for maximum break torque (MBT) and normalized rate for heat release. Additionally, susceptibility of 20% and 60% butanol-gasoline blends on combustion knock was investigated. Simultaneously, comparison between these fuels and pure gasoline in the above areas was investigated. Finally, on the basis of these conclusions, characteristic of these fuel blends as substitutes of gasoline for a series production engine were discussed.     

Unraveling the cooperative effects of acid sites and kinetics for pyrolysis of CHF3 to C2F4 and C3F6 on SO42−/ZrO2-SiO2

The treatment or upgrading of waste trifluoromethane (CHF₃, R23), which has a significant greenhouse effect, is of great importance in industry. Herein, series of SO₄²⁻/ZrO₂-SiO₂ catalysts with different Brønsted and Lewis acid site densities and ratios were prepared for pyrolysis of R23 to tetrafluoroethylene (C₂F₄, TFE) and hexafluoropropylene (C₃F₆, HFP). The effects of impregnation concentration of (NH₄)₂SO₄ on specific surface area, crystal phase, and Brønsted and Lewis acid site densities and ratios were respectively demonstrated. The Brønsted and Lewis acid sites were observed to have cooperative effects on R23 transformation and up to 94.6% selectivity of (TFE + HFP) could be achieved at 750°C. The kinetic studies revealed the decomposition of R23 into CF₂ carbene and HF was the rate-determining step, and a deactivation behavior was found due to the site coverage and pore blockage by the oligomers of TFE and HFP.     

Stronger Together: Multivalent Phage Capsids Inhibit Virus Entry

Antivirals are now more important than ever. To efficiently inhibit virus replication, antiviral multivalent strategies need sufficient affinity to overcome the excellent matching between the virus and its receptor. This report highlights a phage capsid scaffold strategy that can be used to precisely position sialic acid moieties to inhibit influenza A virus replication.     

一种车辆云计算中共享失效检测器

为更好地解决车辆云计算中车辆的高度动态性对失效检测性能的影响,提出了一种适用于车辆云计算环境的基于检测结果共享机制的失效检测器.首先,对车辆云计算的系统架构进行了分析,发现车辆云计算系统具有明显的层次结构,而且可以利用路侧单元对车辆节点进行分组.在此基础之上,引进检测结果共享机制,提出针对车辆云计算环境的共享失效检测器VC-FD.然后,构建了可以对所提出的失效检测器进行定量分析的共享失效检测模型,该模型主要针对检测时间、平均错误发生概率以及检测负载三个失效检测服务质量指标进行评价.最后,在仿真环境下比较和分析了所提出的共享失效检测器与非共享失效检测器的性能.实验结果表明,该失效检测器在保证检测准确性的前提下,通过增加有限的检测负载能够明显地改善系统中节点失效检测时间.因此,提出的基于检测结果共享机制的失效检测器VC-FD能够准确、快速的发现车辆云计算中的节点失效,有效地降低车辆高度动态性对失效检测性能的影响.     

主-从式多弹头协同攻击建模及输出一致性

随着反导系统拦截概率与拦截效率越来越高,单枚弹道导弹突破反导系统实现打击任务的概率在逐渐降低,多弹道导弹协同攻击应运而生.自由飞行段的多弹道导弹易于实现协同攻击,导弹在此阶段也称为弹头.为解决多弹道导弹自由飞行段多弹头协同攻击的建模及输出一致性问题,考虑多弹头协同攻击要求及特点,首先建立了多弹头自由飞行段三维空间运动非线性状态空间模型,详细分析了该模型的特点以及模型非线性动态对多弹头协同攻击带来的挑战.针对上述挑战,为实现主-从式多弹头协同攻击体系的输出一致性,应用输入输出反馈线性化控制方法,设计了一类从弹弹头协同加速度指令信号,并通过详实的数值仿真验证所设计指令信号的有效性.仿真结果表明,沿主弹弹头发射坐标系各轴向均实现了给定性能要求下的主-从式多弹头协同攻击体系的输出一致性,主弹弹头速度变化越快、收敛系数的实部模值越大,速度跟踪误差收敛速度便越快,速度跟踪误差也越小,输出一致性的性能也更好.     

云制造单一制造商与供应商联盟二阶段博弈模型

针对云制造服务链稳定问题,提出了单一制造商同供应商联盟进行谈判的二阶段领导者-追随者博弈模型.该模型根据云制造实际情境,假设制造商决定订单或服务的数量和价格,将云制造过程中制造商与供应商的合作过程抽象为两阶段的博弈,其中第一阶段为面向供应商联盟的竞争博弈,第二阶段为制造商同供应商联盟的合作博弈,并分析了合作策略选择机理.模型分析结果表明,优质供应商个体采用联盟形式,可以获得更高议价权和利益,并可对保持云制造服务链的稳定发展提供一定的决策支持.