Time-sharing parallel applications through performance-targeted feedback-controlled real-time scheduling

Most parallel machines, such as clusters, are space-shared in order to isolate batch parallel applications from each other and optimize their performance. However, this leads to low utilization or potentially long waiting times. We propose a self-adaptive approach to time-sharing such machines that provides isolation and allows the execution rate of an application to be tightly controlled by the administrator. Our approach combines a periodic real-time scheduler on each node with a global feedback-based control system that governs the local schedulers. We have developed an online system that implements our approach. The system takes as input a target execution rate for each application, and automatically and continuously adjusts the applications’ real-time schedules to achieve those rates with proportional CPU utilization. Target rates can be dynamically adjusted. Applications are performance-isolated from each other and from other work that is not using our system. We present an extensive evaluation that shows that the system remains stable with low response times, and that our focus on CPU isolation and control does not come at the significant expense of network I/O, disk I/O, or memory isolation.

Towards Physarum Robots: Computing and Manipulating on Water Surface

Plasmodium of Physarum polycephalum is an ideal biological substrate for implementing concurrent anu parauel computation, including combinatorial geometry and optimization on graphs. The scoping experiments on Physarum computing in conditions of minimal friction, on the water surface were performed. The laboratory and computer experimental results show that plasmodium of Physarum is capable of computing a basic spanning tree and manipulating of light-weight objects. We speculate that our results pave the pathways towards the design and implementation of amorphous biological robots.     

Determination of anthocyanins and exploration of relationship between their composition and petal coloration in crape myrtle (Lagerstroemia hybrid)

Petal coloration and pigment components in 12 American crape myrtle cultivars (Lagerstroemla indica x Lagerstroemla fauriei) and five Chinese crape myrtle cultivars (L. indica hybrids) were studied. Color was measured by ClEL'a'b" scale and anthocyanin composition of crape myrtle was determined using high-performance liquid chromatography coupled to photodiode array detection and electrospray ionization mass spectrometry. The presence of the previously reported delphinidin 3-O-glucoside, petunidin 3-O-glucoside and malvidin 3-O-glucoside were confirmed. Cyanidin 3-O-glucoside was identified in crape myrtle for the first time. We explored the relationship between petal color and anthocyanin contents by multiple linear regression analyses. The results indicated that total flavones and flavonols were important variables and contributed to blue-enhancing in crape myrtle. Based on anthocyanins and co-pigments analysis, flower color breeding in crape myrtle towards true-red and blue were discussed.     

计算生态学的形成与发展

1　计算生态学产生的背景1998年在意大利召开的统计生态学国际大会上 ,与会者普遍认为 ,随着计算机技术的普及和计算方法的推广 ,数字化、模型化、智能化、可视化技术已经被广泛地应用到生态学计算领域中 ,依托计算机技术而进行的生态学计算正蓬勃兴起并迅速发展 ,在生态学中起着越来越重要的作用 ,已经形成了一个新的生态学分支计算生态学 (ｃｏｍｐｕｔｉｎｇｅｃｏｌ ｏｇｙ)。计算生态学的概念一经提出就倍受重视 ,各国的生态学家 ,目前正在努力发展和完善这一新兴学科领域。与其它科学相比 ,计算生态学的产生具有特殊的历史背景。一方…     

Adaptive System Sensitive Partitioning of AMR Applications on Heterogeneous Clusters

This paper presents the design and evaluation of an adaptive system sensitive partitioning and load balancing framework for distributed adaptive mesh refinement applications on heterogeneous and dynamic cluster environments. The framework uses system capabilities and current system state to select and tune appropriate partitioning parameters (e.g., partitioning granularity, load per processor) to maximize overall application performance. Furthermore, it uses dynamic load sensing (using NWS) to adapt to the load dynamics in the cluster.     

Homogeneous Agent-Based Distributed Information Filtering

Recent advances in processor, networking and software technologies have made distributed computing a reality in today's world. Distributed systems offer many advantages, ranging from a higher performance to the effective utilization of physically dispersed resources. Many diverse application domains can benefit by exploiting principles of distributed computing. Information filtering is one such application domain. In this article, we present a design of a homogeneous distributed multi-agent information filtering system, called D-SIFTER. D-SIFTER is based on the language-dependent model of Java RMI. The detailed design process and various experiments carried out using D-SIFTER are also described. The results indicate that the distributed inter-agent collaboration improves the overall filtering performance.     

DNA序列编码的研究进展

DNA计算的可靠性和精确度与编码设计的优劣密切相关。随着DNA计算的发展以及DNA计算研究的进一步深入,对编码的要求也越来越高。围绕如何保证理想的生化反应和解的成功提取问题,人们提出了各种各样的约束条件和评价模型,本文简述了DNA编码的原理,综述了当前DNA序列编码的方法,最后分析了DNA编码设计中存在的问题,并对编码设计的未来发展进行了展望。     

A novel generalized design methodology and realization of Boolean operations using DNA

The biological deoxyribonucleic acid (DNA) strand has been increasingly seen as a promising computing unit. A new algorithm is formulated in this paper to design any DNA Boolean operator with molecular beacons (MBs) as its input. Boolean operators realized using the proposed design methodology is presented. The developed operators adopt a uniform representation for logical 0 and 1 for any Boolean operator. The Boolean operators designed in this work employ only a hybridization operation at each stage. Further, this paper for the first time brings out the realization of a binary adder and subtractor using molecular beacons. Simulation results of the DNA-based binary adder and subtractor are given to validate the design.     

基于三链核酸的DNA计算

一种研究DNA计算的新模型——三链DNA计算模型在本文中提出。此模型是在近年三链核酸的研究成果的基础上建立的。并应用于求解可满足性问题（SAT）,这是一个困难的NP-完全问题。不同于以住的DNA计算方法,基于三链核酸的分子算法通过寡聚脱氧核苷酸（ODN）在RecA蛋白的介导下与同源的双链DNA匹配成三链DNA进行基本的运算,这样可以有效减少计算中的错误。依据分子生物学的实验方法,该算法切实可行并且有效。