Crosstalk-Aware Routing Resource Assignment

Crosstalk noise is one of the emerging issues in deep sub-micrometer technology which causes many undesired effects on the circuit performance. In this paper, a Crosstalk-Aware Routing Resource Assignment (CARRA) algorithm is proposed, which integrates the routing layers and tracks to address the crosstalk noise issue during the track/layer assignment stage. The CARRA problem is formulated as a weighted bipartite matching problem and solved using the linear assignment algorithm. The crosstalk risks between nets are represented by an undirected graph and the maximum number of the concurrent crosstalk risking nets is computed as the max clique of the graph. Then the nets in each max clique are assigned to disadjacent tracks. Thus the crosstalk noise can be avoided based on the clique concept. The algorithm is tested on IBM benchmarks and the experimental results show that it can improve the final routing layout a lot with little loss of the completion rate.     

A parallel genetic algorithm for performance-driven VLSI routing

This paper presents a novel approach to solve the VLSI (very large scale integration) channel and switchbox routing problems. The approach is based on a parallel genetic algorithm (PGA) that runs on a distributed network of workstations. The algorithm optimizes both physical constraints (length of nets, number of vias) and crosstalk (delay due to coupled capacitance). The parallel approach is shown to consistently perform better than a sequential genetic algorithm when applied to these routing problems. An extensive investigation of the parameters of the algorithm yields routing results that are qualitatively better or as good as the best published results. In addition, the algorithm is able to significantly reduce the occurrence of crosstalk     

一种改进的考虑噪声约束的过点分配方法

首先介绍了耦合电容计算、噪声模型选择以及串扰噪声的估计,接着详细分析了一种用于多层无网格区域布线的过点分配算法CPACNC（Crosspoint Assignment with Crosstalk Noise Control）。该算法首先根据障碍物信息将小方块边界分成多个区段,再分两步解CPA问题：CCPA（Coarse Crosspoint Assignment）和DCPA（Detailed Crosspoint Assignment）。针对CPACNC算法在进行边界分解时可能产生许多碎段的缺点,最后提出了一种修正算法,以处理边界分解时产生许多碎段的情况,使CPACNC方法更加有效。     

一种基于反相器减小传感器信号线间串扰方法

传感器信号传输时由于信号线间的电磁耦合产生不可避免的串扰。信号线间串扰严重影响信号线系统信号完整性。针对传感器信号线间串扰提出一种抑制方法,基于反相器防护线减小信号线间串扰方法,该防护线物理结构非常简单,从而很好地减小物理设计成本。通过PSpice软件搭建仿真电路进行仿真验证,仿真结果表明：未采用反相器防护线的受害线受到串扰严重且信号发生误码现象,而采用反相器防护线后受害线串扰现象明显改善且传输信号和原始传输信号100%吻合,从而验证了反相器防护线具有很强的抑制传感器信号线间串扰能力。     

Design of a universal logic block for fault-tolerant realization of any logic operation in trapped-ion quantum circuits

This paper presents a physical mapping tool for quantum circuits, which generates the optimal universal logic block (ULB) that can, on average, perform any logical fault-tolerant (FT) quantum operations with the minimum latency. The operation scheduling, placement, and qubit routing problems tackled by the quantum physical mapper are highly dependent on one another. More precisely, the scheduling solution affects the quality of the achievable placement solution due to resource pressures that may be created as a result of operation scheduling, whereas the operation placement and qubit routing solutions influence the scheduling solution due to resulting distances between predecessor and current operations, which in turn determines routing latencies. The proposed flow for the quantum physical mapper captures these dependencies by applying (1) a loose scheduling step, which transforms an initial quantum data flow graph into one that explicitly captures the no-cloning theorem of the quantum computing and then performs instruction scheduling based on a modified force-directed scheduling approach to minimize the resource contention and quantum circuit latency, (2) a placement step, which uses timing-driven instruction placement to minimize the approximate routing latencies while making iterative calls to the aforesaid force-directed scheduler to correct scheduling levels of quantum operations as needed, and (3) a routing step that finds dynamic values of routing latencies for the qubits. In addition to the quantum physical mapper, an approach is presented to determine the single best ULB size for a target quantum circuit by examining the latency of different FT quantum operations mapped onto different ULB sizes and using information about the occurrence frequency of operations on critical paths of the target quantum algorithm to weigh these latencies. Experimental results show an average latency reduction of about 40 % compared to previous work.     

Three‐dimensional lenticular display synthetic image rendering based on light field acquisition

Crosstalk is a critical defect affecting image quality in multiview lenticular 3D displays. Existing optimization methods require tedious computations and device‐specific optical measurements, and results are often suboptimal. We propose a new method, on the basis of light field acquisition and optimization, for crosstalk reduction in super multiview displays. Theory and algorithms were developed, and experimental validation results showed superior performance.     

Hybrid scan-conversion of circles

Conventional algorithms for scan-conversion of circles select one pixel in each iteration. Run-length slice circle algorithms have therefore been suggested. These algorithms determine a run of pixels in each iteration. The speed of scan-conversion is therefore increased due to I/O. A hybrid approach to the scan-conversion of circles is presented. The new approach combines the advantages of the two methods into a hybrid algorithm. Speedup is achieved in the hybrid algorithm not only due to the reduction in the number of I/O operations, but also due to a reduction in the number of arithmetic operations     

High-performance MCM routing

The authors describe the multilayer MCM (multichip module) routing problem, and propose an approach for routing high-performance MCMs with the objective of minimizing interconnect delays and crosstalk. They first introduce an approach for rapidly estimating the time-domain response of lossy transmission line trees, and propose a realistic second-order delay model for MCM interconnects. The delay model is used to guide a performance-driven global routing algorithm. Given the 2-D global paths, the next stage is layer assignment. An effective algorithm for constrained layer assignment is developed. Based on the best-known maxcut approximation algorithm (which performs well in practice), a maximal k-color ordering is formulated for minimizing both interlayer and intralayer crosstalk as well as crossings in 3-D MCM substrates. The authors also propose a strategy that exhibits a good tradeoff between circuit performance and design cost, instead of concentrating exclusively on a single objective such as area minimization     

基于XDSL串扰噪声的应对技术分析研究

在DSL运行环境中,由于电缆内部线对间的非屏蔽而存在电磁耦合导致的串扰。串扰噪声造成XDSL速率下降甚至重训练,影响业务质量。本文对串扰导致的性能损失和导致重训练的原因进行分析并且就解决串扰导致稳定性问题的方法进行探讨。     

Energy reduction through crosstalk avoidance coding in networks on chip

Commercial designs are currently integrating from 10 to 100 embedded processors in a single system on chip (SoC) and the number is likely to increase significantly in the near future. With this ever increasing degree of integration, design of communication architectures for large, multi-core SoCs is a challenge. Traditional bus-based systems will no longer be able to meet the clock cycle requirements of these big SoCs. Instead, the communication requirements of these large multi processor SoCs (MP-SoCs) are convened by the emerging network-on-chip (NoC) paradigm. Crosstalk between adjacent wires is an important signal integrity issue in NoC communication fabrics and it can cause timing violations and extra energy dissipation. Crosstalk avoidance codes (CACs) can be used to improve the signal integrity by reducing the effective coupling capacitance, lowering the energy dissipation of wire segments. As NoCs are built on packet-switching, it is advantageous to modify data packets by including coded bits to protect against the negative effects of crosstalk. By incorporating crosstalk avoidance coding in NoC data streams and organizing the CAC-encoded data packets in an efficient manner, so that total number of encoding/decoding operations can be reduced over the communication channel, we are able to achieve lower communication energy, which in turn will help to decrease the overall energy dissipation.     

A new algorithm for complex product flexible scheduling with constraint between jobs

In order to simplify the complex product flexible scheduling problem with constraint between jobs, a new hierarchical scheduling algorithm based on improved processing operation tree is presented. Aiming at the routing problem, short-time strategy and machine-balance strategy are adopted to assign each operation to a machine out of a set of machines. And in order to solve the sequencing problem, the allied critical path method is first adopted to confirm the scheduling sequence of operations, and then operations are divided into dependent operations and independent ones according to their characteristics. For the dependent operations, forward greedy rule is adopted in order to make the completion time of operation as soon as possible and the scheduling algorithm of shortening idle time is adopted by analyzing the characteristics of the independent operations. Experiment shows that the proposed algorithm solves for the first time the complex product flexible scheduling problem with constraint between jobs.     

串扰最小化的网格模式下的双层通道布线

超深亚微米IC设计中互连线的串扰情况与详细布线方案和信号波形密切相关。基于这一事实，在网格模式下的通道布线算法中建立了最小化串扰的目标函数。提出获得最小化串扰布线方案的方法。与以往算法不同的是，本方法将相邻平行线间信号跳变的方式和频度作为目标函数中的影响因子。可以更准确地估计出布线区内串扰总和的大小。并且通过构造布线生成树的方法求得精简的布线方案。有效地减少了求解具有最小串扰的布线方案的计算量。     

调整门和连线尺寸以减小串扰的拉格朗日松弛法

本文给出了一个布线后减小串扰噪声的算法。该算法通过调整逻辑门和互连线的尺寸有效地减小了串扰噪声,在减小噪声的同时约束电路的最大延时,使得在串扰噪声和时序都满足约束的条件下最小化芯片面积。算法保证了改变逻辑门和线网尺寸不会破坏电路的时序约束。实验结果证明,本算法有效地减小了串扰。此算法不需回到布线阶段来优
优化串扰,减少了设计迭代次数,加快了设计收敛时间。     

一种新的MPLS流量工程路由算法MSMR

本文提出了一种新的用于多协议标签交换网络流量工程的动态路由算法。先前研究者们提出的MIRA等著名算法试图通过绕开关键链路而最小化不同源-目的节点对之间的干涉。但是,有些情况下,这些算法可能选择过长的路径,或在寻找关键路径时判断不准确。因而本文提出了一种新的最大化其它入出口对之间的最大流之和的启发式算法。模拟结果证明了算法在拒绝率和吞吐量方面达到了更好的性能。     

一种在VLSI电路物理设计中减小串扰的优化算法

通过研究调整线段和线间距对串扰的影响,提出了一种在布线时通过采线段摄动和压缩线间距的措施来减小串扰的优化算法,计算机仿真结果表明,该算法能有效地减少芯片中的串扰,此外,可预期算法应用于布线区域不规则的情形。     

Energy-aware routing in the Cognitive Packet Network

An energy aware routing protocol (EARP) is proposed to minimise a performance metric that combines the total consumed power in the network and the QoS that is specified for the flows. The algorithm uses source routing based on the functionalities provided by the Cognitive Packet Network (CPN), running autonomously at each input node to the network based on smart packets which gather relevant information throughout the network using reinforcement learning at each of the intermediate nodes. Measurements on an experimental test-bed that uses EARP are presented and they indicate that it offers a reduction in power consumption, as compared to a purely QoS driven approach, and also respects the requested QoS level.     

一种基于单播的大规模Mesh网络容错多播路由新算法

本文基于k-Mesh子网连通的概念提出一种基于局部信息和分布式的Mesh网络容错多播路由算法：该算法的基本思想是把大规模的Mesh网络分成若干个较小的子网，多播消息只在各子网间进行路由，并由各子网独立完成操作。该算法的时间复杂性是线性的，模拟结果表明多播路由算法的多播时间步接近网络的直径。     

A hybrid particle swarm optimization algorithm for the vehicle routing problem

This paper introduces a new hybrid algorithmic nature inspired approach based on particle swarm optimization, for successfully solving one of the most popular supply chain management problems, the vehicle routing problem. The vehicle routing problem is considered one of the most well studied problems in operations research. The proposed algorithm for the solution of the vehicle routing problem, the hybrid particle swarm optimization (HybPSO), combines a particle swarm optimization (PSO) algorithm, the multiple phase neighborhood search–greedy randomized adaptive search procedure (MPNS–GRASP) algorithm, the expanding neighborhood search (ENS) strategy and a path relinking (PR) strategy. The algorithm is suitable for solving very large-scale vehicle routing problems as well as other, more difficult combinatorial optimization problems, within short computational time. It is tested on a set of benchmark instances and produced very satisfactory results. The algorithm is ranked in the fifth place among the 39 most known and effective algorithms in the literature and in the first place among all nature inspired methods that have ever been used for this set of instances.     

Mix-opt: A new route operator for optimal coverage path planning for a fleet in an agricultural environment

To accomplish agriculture tasks, a field is usually divided into tracks based on the implement width. The order in which the crop tracks are covered during this process is critical because it directly affects the distances travelled by the agricultural machines while completing the task and, consequently, soil compaction and inputs. Identifying the best tracks for a set of vehicles to completely cover a field can be formulated as a capacitated vehicle routing problem (CVRP), in which tracks can be viewed as the customers of the CVRP problem. In other words, given a set of n tracks and m vehicles, the objective is to determine a set of routes such that each track is covered exactly once by any of the involved vehicles while minimizing the total cost of covering all the tracks. There are many metaheuristic optimisation methods that address the CVRP problem by using operators to iteratively improve the routes. Most of these operators consist of easy elementary operations such as relocations, swaps or inversions of the order in which customers in the route are visited. In this paper, a new operator, named Mix-opt, is proposed with the aim of accelerating the convergence of metaheuristic optimisation methods and make them less dependent on the operator chosen on routing problems. The proposed operator combines and extends some of the features of the most commonly used route operators by integrating the best-performing elementary operations on which they are based. Further variants of those elementary operations were tested, such as the use of different numbers of elements in the relocations or swaps or reverse orders as well as combining the operations with local searches. The best variants were selected for integration into the proposed operator. Furthermore, Mix-opt was compared against well-established operators by integrating each of them into a Simulated Annealing algorithm and solving well-known CVRP benchmarks and a typical and complex agricultural routing problem. Finally, the proposed operator was applied to be integrated into an agricultural route planner to identify the best routes in some illustrative agricultural problems.All tests demonstrated that Mix-opt, on average, outperforms existing approaches for solving general routing problems as well as a broad spectrum of agricultural routing situations. This helps to better route plan in agricultural contexts, even better than other approaches in a very short time, which is interesting to route plan in real time, for example, because one vehicle may fail during the execution and then it is necessary to route the plan again and very fast to distribute the remaining part of the global task among the rest of the vehicles in the fleet.     

两扬声器配置下的串声消除系统参数优化设置

针对三维声音两扬声器重放中基本上独立研究逆滤波器的设计或扬声器的配置等因素对串声消除系统（CCS）性能的影响,提出了采用频域最小均方（LS）估计逼近方法,系统考察这些因素之间的关联以及对串声消除性能优化的作用,并通过折中考虑CCS的运算效率及系统性能获得了一组最优参数。实验采用通道分离度（CS）和性能误差（PE）两个指标对串声消除效果进行综合评价,仿真结果表明,该组最优参数能获得很好的串声消除效果。