A parallel strategy for biological sequence alignment in restricted memory space

Recently, many organisms had their DNA entirely sequenced, and this reality presents the need for aligning long DNA sequences, which is a challenging task due to its high demands for computational power and memory. The algorithm proposed by Smith–Waterman (SW) is an exact method that obtains optimal local alignments in quadratic space and time. For long sequences, quadratic complexity makes the use of this algorithm impractical. In this scenario, parallel computing is a very attractive alternative. In this paper, we propose and evaluate z-align, a parallel exact strategy based on the divergence concept to locally align long biological sequences using an affine gap function. Z-align runs in limited memory space, where the amount of memory used can be defined by the user. The results collected in a cluster with 16 processors presented very good speedups for long real DNA sequences. With z-align, we were able to compare up to 3 MBP (mega base-pairs) DNA sequences. As far as we know, this is the first time 3 MBP sequences are compared with an affine gap exact variation of the SW algorithm. Also, by comparing the results obtained with z-align and the popular BLAST tool, it is clear that z-align is able to produce longer and more significant alignments.     

One-to-one communication in twisted cubes under restricted connectivity

The dimensions of twisted cubes are only limited to odd integers. In this paper, we first extend the dimensions of twisted cubes to all positive integers. Then, we introduce the concept of the restricted faulty set into twisted cubes. We further prove that under the condition that each node of the n-dimensional twisted cube TQ _n has at least one fault-free neighbor, its restricted connectivity is 2n − 2, which is almost twice as that of TQ _n under the condition of arbitrary faulty nodes, the same as that of the n-dimensional hypercube. Moreover, we provide an O(NlogN) fault-free unicast algorithm and simulations result of the expected length of the fault-free path obtained by our algorithm, where N denotes the node number of TQ _n . Finally, we propose a polynomial algorithm to check whether the faulty node set satisfies the condition that each node of the n-dimensional twisted cube TQ _n has at least one fault-free neighbor.     

L空间和P空间模型下的树状结构网络

针对两类树状输运网络——自然演化的克隆植物网络和人工建造的城市地铁网络,构建L空间和P空间下相应的网络模型,通过网络拓扑结构特征和随机树两个角度进行比对分析.研究发现,虽然这两类网络构建目的不同,但它们在L空间和P空间下都展现出相似的拓扑结构;同时将这两个网络的结构与随机分支树进行比较,发现它们以相同的方式和程度偏离随机分支树的预估值.     

Biomechanical analysis of accurately and carefully placing an aerospace avionics box in restricted space

The design of a spacecraft has many trade-offs to reduce its mass, which typically result in reduced work space for the installation of Line Replaceable Units (LRU). One common LRU in aerospace vehicles is the avionics box found in the space shuttle. To prevent damage to cold plates, the installation of these boxes requires designing for accurate and careful placement; yet there are no standards to follow nor studies to consider for designers concerning human limitations for installing boxes accurately and carefully. In the literature, there are an abundance of lifting studies; however, there are only a few studies that have placed a box in restricted space or on a target as a constraint. Of those studies, only three have looked at the biomechanics, and none of those studies have looked at factors affecting the Placement Control (accurate and careful placement) of a box on a target in restricted or unrestricted space. Thus, the focus of this study is to determine the biomechanical stresses and the human performance metrics for Placement Control (accurate and careful placement) of a box on target in restricted space.     

Connectivity requirements for Byzantine agreement under restricted types of failures

We investigate the problem of reaching Byzantine Agreement in arbitrary networks where both processors and communication links are subject to omission or stopping faults. For the case of deterministic, synchronous algorithms we give a necessary and sufficient condition relating the solvability of the problem to the connectivity of the network. In particular, we show that an algorithm resilient to at mostt faulty processors andk faulty links subject to omission or stopping faults exist, if and only if the network has a connectivity pair (t, k)>(t, k).Vassos Hadzilacos received his BSE from Princeton in 1980 and his PhD from Harvard in 1984, both in Computer Science. He is presently an Assistant Professor at University of Toronto. His research interests are synchronisation and reliability in distributed computing. He is a co-author of a book on Concurrency Control and Reliability in Database Systems.     

给定手部作业轨迹的仿人机器人推操作研究

以推车作业为例对“汇童”仿人机器人动态行走中的推操作进行了研究,分析了手部位置与腰部位 移的关系,对作业运动中手部轨迹的补偿进行了研究．另外,作业中机器人与车之间存在相互作用,根据作业的 期望作用力,开展了基于ZMP 稳定性判据的作业运动稳定性控制研究．仿真和实验验证了该方法的有效性,它能 满足推车作业手臂操作性和运动稳定性要求．     

Profile inference on partially linear varying-coefficient errors-in-variables models under restricted condition

In this paper, we investigate the estimation and testing problems of partially linear varying-coefficient errors-in-variables (EV) models under additional restricted condition. The restricted estimators of parametric and nonparametric components are established based on modified profile least-squares method, and their asymptotic properties are also studied under some regularity conditions. Moreover, the modified profile Lagrange multiplier test statistic is constructed under additional restricted condition. It is shown that the modified profile Lagrange multiplier test statistic is asymptotically distribution-free and follows a Chi-squared distribution under the null hypothesis. Some simulation studies are carried out to assess the performance of the proposed methods. A real dataset is analyzed for illustration.     

A NLP approach for evaluating storey-buckling strengths of steel frames under variable loading

The problem of determining elastic buckling strengths for unbraced steel frames under variable loading is investigated in this paper. Whereas the pattern of applied loads is specified prior to stability analysis of a frame under proportional loading, load patterns are not predefined in variable loading. The conventional methods for evaluating the stability strength of unbraced frames under proportional loading are not applicable for variable loading, since the load pattern is unknown. Taking into account the concept of storey-based buckling, the problem of frame stability under variable loading is presented as a pair of minimization and maximization problems subject to stability constraints, which are solved by a nonlinear programming (NLP) method. The proposed variable loading approach takes into account the variability of applied loads during the life span of the structure, and as such, provides accurate evaluation of elastic frame-buckling strengths.     

Fuzzy reasoning model under quotient space structure

In this paper, we present a theoretical framework of fuzzy reasoning model under quotient space structure. It consists of (1) introducing quotient space structure into fuzzy sets, i.e., constructing fuzzy set representations of different grain-size spaces and their relationships; (2) introducing the concept of fuzzy sets into quotient space theory, i.e., introducing fuzzy equivalence relation and discussing its corresponding reasoning in different grain-size spaces; and (3) discussing the relationship and transformation among different granular computing methodologies. The framework proposed is aimed to combine two powerful abilities in order to enhance the efficiency of fuzzy reasoning: one is the ability of computing with words based on fuzzy set methodology, the other is the ability of hierarchical problem solving based on quotient space approach.     

Tracking of dynamic objects under conditions of a restricted angle information rate

Features of construction of systems for tracking of dynamic objects with a restricted angle information rate are investigated with regard to linear filtering and extrapolation. Guidelines for requirements for the error detector based on the dynamic properties of the set of tracked objects are developed. The simulation is carried out under conditions as close to the actual measurement process as possible.     

存储空间约束下物化视图的选择

介绍一种进化算法,通过利用并改进随机排列算法来实现在存储空间约束下物化视图的选择和物化视图维护代价的总和最小。该改进算法能有效地得到一个近似最优解的解决方案。最后介绍了该算法在公安数据仓库设计中的应用。     

Searching minimax game trees under memory space constraint

Games such as CHESS, GO and OTHELLO can be represented by minimax game trees. Among various search procedures to solve such game trees,- and SSS^* are perhaps most well known. Although it is proved that SSS^* explores only a subset of the nodes explored by-, - is commonly believed to be faster in real applications, since it requires very little memory space and hence its storage management cost is low. Contrary to this folklore, however, this paper reports, using the OTHELLO game as an example, that SSS^* is much faster than-. It is also demonstrated that SSS^* can be modified to make the required memory space controllable to some extent, while retaining the high efficiency of the original SSS^*.This research was partially supported by the Ministry of Education, Science and Culture of Japan, under a Scientific Grant-in-Aid.     

基于同一特征空间的多模态脑肿瘤分割方法

脑胶质瘤的分割依赖多种模态的核磁共振成像（MRI）的影像。基于卷积神经网络（CNN）的分割算法往往是在固定的多种模态影像上进行训练和测试,这忽略了模态数据缺失或增加问题。针对这个问题,提出了将不同模态的图像通过CNN映射到同一特征空间下并利用同一特征空间下的特征来分割肿瘤的方法。首先,不同模态的数据经过同一深度CNN提取特征;然后,将不同模态的特征连接起来,经过全连接层实现特征融合;最后,利用融合的特征实现脑肿瘤分割。模型采用BRATS2015数据集进行训练和测试,并使用Dice系数对模型进行验证。实验结果表明了所提模型能有效缓解数据缺失问题。同时,该模型较多模态联合的方法更加灵活,能够应对模态数据增加问题。