Modified Hopfield neural networks for retrieving the optimalsolution

Due to the rugged energy function of the original Hopfield networks, the output is usually one local minimum in the energy function. An analysis on the locations of local minima in Hopfield networks is presented, and a modified network architecture to eliminate such local minima is described. In particular, another amplifier is introduced at the processor nodes to give correction terms. This modified Hopfield network has been successfully applied to the construction of analog-to-digital converters with optimal solutions. Experimental results on the voltage transfer characteristics of data converters are presented.     

基于预读策略的节能数据访问技术

传统节能策略通过控制组件状态切换来节省能耗,但状态切换本身需要耗费一定能量。为此,提出一种基于预读策略的节能数据访问技术。引入文件系统数据访问中的预读方式,读取数据并将其聚合到一起进行访问,减少设备组件的状态切换,从而实现降低能耗的目的。实验结果表明,在多媒体数据访问方式下使用该技术能节省70%以上的磁盘能耗。     

基于模板匹配和遗传算法的人眼定位

文中提出了一种利用模板匹配与遗传算法相结合的人眼定位算法.根据人脸几何特征将人脸分为几个特征区域(眼睛、鼻子、嘴巴),在找到人眼区域后根据人眼几何特征,建立人眼特征模板及其能量函数,通过改变模型参数用遗传算法实现能量函数的全局最小化,使能量函数最小的模型参数即可描述人眼的特征,从而实现人脸特征的有效定位.同时还讨论了不同的能量函数在人眼定位过程中的地位和作用.可避免在能量函数寻优过程中的局部最小化的出现,较准确较快捷的确定人脸主要特征的位置.     

Optimal design and operation of a wastewater purification system

Due to the importance of coastal areas, is of the highest interest to implement purification systems that with minimum cost are able to assure water quality standards in agreement with the regional legislations. This work addresses the optimal design (outfall locations) and optimal operation (level of oxygen discharges) of a wastewater treatment system. This problem can be mathematically formulated as a two-objective mixed design and optimal control problem with constraints on the states and the design and control variables.     

A new strain energy theorem and its use in the optimum design of continuous beams

The subject of this paper is the design of a continuous beam for optimum support geometry. The design variables are a preselected set of simple support locations and the objective function is the strain energy of the beam. It is shown that the design for minimum strain energy is close to the design for minimax bending moment A theorem is presented stating that the strain energy is minimized with respect to the location of simple supports if the slopes of the elastic curve of the beam at the supports are zero. Based on the theorem an efficient iterative procedure for the minimization of the energy is presented. A simple computer program implements the technique for a large class of problems. This program is very economical compared to any of the standard minimization packages.     

Some Problems of Analysis of Hybrid Automata

A class of 1-dimensional hybrid automata is defined in which the dynamics at each discrete state for different sets of initial values of a continuous state can be represented by different differential equations, and a finite duration of this dynamics, which can be different for different sets of initial values of such a continuous state, is specified. Algorithms are proposed to solve problems of eliminating contradictions in the objects that define a hybrid automaton, matching these objects with one another, finding the minimum number of switchings, and estimating the minimum time required to reach discrete states from a set of initial discrete states.     

云计算环境下的节能任务调度策略的随机Petri网分析

针对当前云计算异构服务器集群环境下的高能耗问题,提出一种最小能耗优先的任务调度策略(first sche-duling with minimum energy)。该策略在调度任务时优先考虑处于运行状态的服务器,并以任务响应时间为约束,按照最小能耗原则将任务分配到相应的服务器上执行。当处于运行状态的服务器都不能满足任务对响应时间的要求时,则考虑处于休眠状态的服务器;同时,也基于最小能耗原则进行调度。采用随机Petri网工具对节能任务调度策略进行分析建模,考虑其能耗和相关性能指标。实验结果表明,该方法不仅能满足任务的QoS性能要求,而且具有较好的节能效果。     

不同位置四点支承矩形薄板的自由振动特性

研究不同位置四点支承条件下矩形薄板的自由振动特性.首先,在板结构模型的不同位置上引入横向约束弹簧,并设定人工弹簧的刚度值以模拟出四点支承的边界条件.然后,基于二维改进傅里叶级数表示结构的位移容许函数,其中改进部分的正弦附加项可解决以往位移函数在边界上可能存在的求导不连续问题.建立矩形板系统能量对应的泛函,令其取驻值建立线性方程组.最后,求解矩阵特征值问题得到点支承矩形板自由振动频率等参数,给出不同位置四点支承条件下矩形薄板的振动特性.所应用二维改进傅里叶级数法中,位移函数基于改进傅里叶级数展开时的附加项能够提高结果的精度和收敛速度.研究结果为不同位置点支承矩形板的自由振动问题提供一定的参考.     

Design of the Inverse Function Delayed Neural Network for Solving Combinatorial Optimization Problems

We have already proposed the inverse function delayed (ID) model as a novel neuron model. The ID model has a negative resistance similar to Bonhoeffer–van der Pol (BVP) model and the network has an energy function similar to Hopfield model. The neural network having an energy can converge on a solution of the combinatorial optimization problem and the computation is in parallel and hence fast. However, the existence of local minima is a serious problem. The negative resistance of the ID model can make the network state free from such local minima by selective destabilization. Hence, we expect that it has a potential to overcome the local minimum problems. In computer simulations, we have already shown that the ID network can be free from local minima and that it converges on the optimal solutions. However, the theoretical analysis has not been presented yet. In this paper, we redefine three types of constraints for the particular problems, then we analytically estimate the appropriate network parameters giving the global minimum states only. Moreover, we demonstrate the validity of estimated network parameters by computer simulations.      

Optimal solutions for cellular neural networks by paralleledhardware annealing

An engineering annealing method for optimal solutions of cellular neural networks is presented. Cellular neural networks are very promising in solving many scientific problems in image processing, pattern recognition, and optimization by the use of stored program with predetermined templates. Hardware annealing, which is a paralleled version of mean-field annealing in analog networks, is a highly efficient method of finding optimal solutions of cellular neural networks. It does not require any stochastic procedure and henceforth can be very fast. The generalized energy function of the network is first increased by reducing the voltage gain of each neuron. Then, the hardware annealing searches for the globally minimum energy state by continuously increasing the gain of neurons. The process of global optimization by the proposed annealing can be described by the eigenvalue problems in the time-varying dynamic system. In typical nonoptimization problems, it also provides enough stimulation to frozen neurons caused by ill-conditioned initial states.     

基于近似匹配的假位置k-匿名位置隐私保护方法

为了提高假位置k-匿名位置隐私保护方法中的假位置生成效率和查询服务质量,以及解决假位置生成过程中预处理复杂、没有充分考虑地理语义信息特征等问题,提出一种基于近似匹配的假位置k-匿名位置隐私保护方法.首先,将所选区域划分为若干个正方形网格,并将各位置坐标按所在网格转换为莫顿码;然后,通过对各位置莫顿码之间的近似匹配,选取互不相邻、分布在不同网格的位置点,生成假位置候选集;最后,对候选集中位置点的地名信息进行近似匹配, 得到位置点之间的语义相似度, 并选取语义相似度最小的$k-1$个位置点作为假位置.实验结果表明,所提出的方法在保证假位置之间物理分散性和语义多样化的同时,能够提高假位置生成效率,有效平衡隐私保护效果和查询服务质量.     

Optimal control of multi-level quantum system with energy cost functional

In this paper we have synthesized optimal control of multi-level quantum system by representing unitary operator in terms of the projection operators of the Hamiltonian of the system. We have solved the steering problem for multi-level quantum systems minimizing energy cost functional of the control. The optimal control problem of the time evolution of quantum spin of Pauli two-level system subjected to an external field with the minimum energy function is also illustrated and formulated in terms of the quantum spin up and spin down states of the Pauli two-level system.     

动态储位分配策略下仓储作业能耗优化调度

针对堆垛机式自动化立体仓库能耗优化任务调度问题,提出了一种动态储位分配策略下的任务调度集成优化方法。该策略允许在当前任务执行批次内重用拣货产生的空库位,产生了任务顺序约束;并结合不同运动状态下堆垛机的运行时间计算差异,建立了复合指令下以堆垛机任务总能耗最低为目标的调度模型。依据模型的特点,提出了一种改进帝国竞争算法进行求解。该算法通过设置校正机制使优化解能够满足任务顺序约束,并引入外来种群入侵的概念来避免算法陷入“早熟”。最后通过两组数据对提出的任务调度算法进行了验证,实验结果表明,改进算法在能耗和任务执行效率方面优于其他方法,能够有效减少堆垛机作业过程能耗,提升作业效率。     

Energy optimization for multi-level cell non-volatile memory using state remapping

Non-volatile Memory (NVM) is emerging as a promising technology to build future main memory or cache. Multi-level cell (MLC) NVM that stores multiple bits in a single cell has been developed in recent years. Different NVM technology has its own writing schemes to store multiple bits, and the amount of write energy varies across different states. For MLC Phase-Change Memory (PCM), the energy consumption of writing intermediate states, ‘01’ and ‘10’, is bigger than that of writing states ‘00’ and ‘11’. For MLC Spin-Transfer Torque Magnetic RAM (STT-MRAM), the energy consumption of flipping the left bit of a 2-bit cell is greater than that of flipping the right bit. To reduce the MLC NVM write energy consumption, we propose an encoding scheme to reduce the amount of intermediate states’ write for MLC PCM and another encoding scheme to decrease the number of the left bit flips for MLC STT-MRAM. The main idea of both schemes is state remapping. We find two minimum write frequency states and remap them to state ‘01’ and ‘10’ respectively for MLC PCM. In addition, for MLC STT-MRAM, we seeks the remapping decision that can minimize the number of the left bit flips and reduces the write of states ‘01’ and ‘10’. The experimental results show that the encoding scheme for MLC PCM saves 5.25% energy on average and the encoding scheme for MLC STT-MRAM saves 12.17% energy on average.     

A step-by-step dual cycle sequencing method for unit-load automated storage and retrieval systems

The sequencing of requests in an automated storage and retrieval system was the subject of many studies in literature. However, these studies assumed that the locations of items to be stored and retrieved are known and the sequencing problem consisted in determining a route of minimal travel time between these locations. In reality, for a retrieval request, an item can be in multiple locations of the rack and so there is a set of locations associated with this item and not only one predetermined location in the rack. In this paper, we deal with the sequencing problem where a required product can be in several rack locations and there is a set of empty locations. Consequently, the retrieval and storage locations are not known a priori. We sequence by the minimum travel time of a double cycle (DC). An optimization method working step-by-step is developed to determine for each DC and according to storage and retrieval requests, the location of the item to be stored and the location of the item to be retrieved allowing the minimum DC time. The storage requests are processed in FCFS and retrieval requests retrievals requests are gathered by block according to wave sequencing.     

A step-by-step dual cycle sequencing method for unit-load automated storage and retrieval systems

The sequencing of requests in an automated storage and retrieval system was the subject of many studies in literature. However, these studies assumed that the locations of items to be stored and retrieved are known and the sequencing problem consisted in determining a route of minimal travel time between these locations. In reality, for a retrieval request, an item can be in multiple locations of the rack and so there is a set of locations associated with this item and not only one predetermined location in the rack. In this paper, we deal with the sequencing problem where a required product can be in several rack locations and there is a set of empty locations. Consequently, the retrieval and storage locations are not known a priori. We sequence by the minimum travel time of a double cycle (DC). An optimization method working step-by-step is developed to determine for each DC and according to storage and retrieval requests, the location of the item to be stored and the location of the item to be retrieved allowing the minimum DC time. The storage requests are processed in FCFS and retrieval requests retrievals requests are gathered by block according to wave sequencing.     

矿井搜救探测机器人驱动系统最小能耗建模与影响因素分析

研究了矿井搜救探测机器人最小能耗影响因素。针对直流伺服电机和减速齿轮驱动下的移动机器人驱动系统,利用Hamiltonian函数与最小值原理求解出驱动系统的最优速度函数和最优控制电流函数,建立了非线性摩擦条件下的最小能耗模型。通过MATLAB仿真,分析了减速器效率[η]、负载、库仑摩擦力和粘性摩擦系数等因素对最小能耗的影响,确定了各参数对驱动系统最小能耗的影响规律。为矿井搜救探测机器人驱动系统消耗能量最小进行参数配置提供依据,对实现机器人节能降耗具有现实的意义。     

Asymptotic properties of empirical estimates for parameters of markov sequences

This article considers conditions under which the criterion function of a Markov process with a unique minimum point can be approximated by its empirical estimate. Theorems on the convergence of an empirical function to the original one in some probabilistic sense are established for both finite and compact sets of states of the Markov process.     

Web-based distributed system and database modeling for concurrent design

This research introduces a new approach for Web-based collaborative concurrent design. In this approach, systems, product libraries, and product databases for modeling different product development life-cycle aspects are distributed at different locations that are linked through the Web. Product modeling libraries are described as class features. A class feature at a remote location can be used for defining a new class feature at the local site. Product modeling systems distributed at different locations are used for creating product databases that are described by instance features. A system at one location can be implemented using the functions provided at other locations as the components. Different life-cycle databases at different locations are associated by their relations. The optimal design considering relevant life-cycle aspects is identified using the distributed product life-cycle modeling systems and databases.     

Fuel and energy system control at large-scale damages. 1. Network model and software implementation

A dynamic network flow model for analyzing aggregated energy supply processes, including the extraction, processing, transport, transformation, and redistribution of the main fuel and energy resources is prorosed. The changes in the functional characteristics of the energy system under large-scale disturbances are analyzed. The model is used to identify control strategies for energy flows in a damaged network. During optimization calculations, the set of problems on a single-product flow of the minimum value is solved. In addition, the software system based on the proposed model is described. The software system has an option to specify the locations of damage and scenarios for the subsequent restoration of network elements with the aim of fulfilling the user demands on the amount of energy supply. The proposed approach can be used to analyze the functional vulnerability of spatially distributed resource supply systems.