Experiences in benchmarking the three supercomputers CRAY-1M, CRAY-X/MP, FUJITSU VP-200 compared with the CYBER 76

The speed of the three supercomputers CRAY-1M, CRAY-X/MP, FUJITSU VP-200 is measured several times. There exist technical numbers like cycle time, start-up times, etc. and numbers for the speed of basic arithmetic operations depending on the vector length, for kernel programs and for a few special production programs. In this article some numbers and some experiences are given for a broader program set, real production programs from a heterogenous workload, typical for a university computer center environment with technical oriented research problems. The intention was to measure the relative speed to the CONTROL DATA CYBER 76, the main computer which the Regionales Rechenzentrum für Niedersachsen (RRZN) at the University of Hannover has operated for more than 10 years. For replacing this computer some investigations were necessary for benchmarking some new computers and supercomputers. Experiences are given with the migration of real programs to the supercomputers and a used benchmark is described. The measured speed factors are given for the three supercomputers compared with the CYBER 76. Very remarkable is the big range of the different speed factors. Some global thoughts about benchmarking, the interpretation of the results for the used benchmark and some special programs with their effects are discussed.     

ABB MasterPiece200/1控制器系统优化

针对轧机机架控制部分DA4-DA7控制柜内的MP200/1控制器因系统过载频繁发生死机、通信中断等故障,分析过载原因,并提出优化控制程序结构和循环时间、对数据库进行整理以及优化总线通信结构等改进措施.     

基于S7-200 PLC的Modbus主从站编程与应用

从工程需求出发,提出了利用S7-200 PLC集成免费的Modbus RTU主站和从站通信库,以一个典型实例编程实现S7-200PLC作为工业自动化领域含Modbus通信协议的网络中间设备,具有很好的实用价值。     

Perspectives of China’s HPC system development: a view from the 2009 China HPC TOP100 list

The China HPC TOP100 list, an annual report of the 100 most powerful high performance computing (HPC) systems installed in mainland China, has traced the rapid growth of HPC technology in China since its first publication in 2002. This paper introduces the China HPC TOP100 list and reviews the current status of HPC systems in China in terms of system features, manufactures, and areas of application using the data reported in the most recent list, published on November 1st, 2009. We provide further analysis, prediction of future trends, and directions of the development of HPC systems in China referencing historical data accumulated through archived TOP100 lists and other publically available information. We predict that the aggregated Linpack performance of the top 100 HPC systems will reach 10 PFlops in 2011, a single system with 10 PFlops peak performance will appear between 2012 and 2013, the aggregated performance of the top 100 systems will reach 100 PFlops in 2014, and a single system with 100 PFlops peak performance will appear around 2015.     

Protein profiling of oral brush biopsies: S100A8 and S100A9 can differentiate between normal, premalignant, and tumor cells

In oral mucosa lesions it is frequently difficult to differentiate between precursor lesions and already manifest oral squamous cell carcinoma. Therefore, multiple scalpel biopsies are necessary to detect tumor cells already in early stages and to guarantee an accurate follow‐up. We analyzed oral brush biopsies (n = 49) of normal mucosa, inflammatory and hyperproliferative lesions, and oral squamous cell carcinoma with ProteinChip Arrays (SELDI) as a non‐invasive method to characterize putative tumor cells. Three proteins were found that differentiated between these three stages. These three proteins are able to distinguish between normal cells and tumor cells with a sensitivity of 100% and specificity of 91% and can distinguish inflammatory/hyperproliferative lesions from tumor cells with a sensitivity of up to 91% and specificity of up to 90%. Two of these proteins have been identified by immunodepletion as S100A8 and S100A9 and this identification was confirmed by immunocytochemistry. For the first time, brush biopsies have been successfully used for proteomic biomarker discovery. The identified protein markers are highly specific for the distinction of the three analyzed stages and therewith reflect the progression from normal to premalignant non‐dysplastic and finally to tumor tissue. This knowledge could be used as a first diagnostic step in the monitoring of mucosal lesions.     

Improvising through the senses: a performance approach with the indirect use of technology

This article explores and proposes new ways of performing in a technology-mediated environment. We present a case study that examines feedback loop relationships between a dancer and a pianist. Rather than using data from sensor technologies to directly control and affect musical parameters, we captured data from a dancer’s arm movements and mapped them onto a bespoke device that stimulates the pianist’s tactile sense through vibrations. The pianist identifies and interprets the tactile sensory experience, with his improvised performance responding to the changes in haptic information received. Our system presents a new way of technology-mediated performer interaction through tactile feedback channels, enabling the user to establish new creative pathways. We present a classification of vibrotactile interaction as means of communication, and we conclude how users experience multi-point vibrotactile feedback as one holistic experience rather than a collection of discrete feedback points.     

Hello ADIOS: the challenges and lessons of developing leadership class I/O frameworks

Applications running on leadership platforms are more and more bottlenecked by storage input/output (I/O). In an effort to combat the increasing disparity between I/O throughput and compute capability, we created Adaptable IO System (ADIOS) in 2005. Focusing on putting users first with a service oriented architecture, we combined cutting edge research into new I/O techniques with a design effort to create near optimal I/O methods. As a result, ADIOS provides the highest level of synchronous I/O performance for a number of mission critical applications at various Department of Energy Leadership Computing Facilities. Meanwhile ADIOS is leading the push for next generation techniques including staging and data processing pipelines. In this paper, we describe the startling observations we have made in the last half decade of I/O research and development, and elaborate the lessons we have learned along this journey. We also detail some of the challenges that remain as we look toward the coming Exascale era. Copyright © 2013 John Wiley & Sons, Ltd.     

On the use of a synthetic online/batch workload for computer selection

The overall evaluation and decision process for the selection of a new computer system for the universities at Graz using a mixed synthetic online/batch workload is described. In particular the method for defining this workload for the evaluation process is explained. Furthermore the possibility of constructing assessment functions, that can be used for the comparison of different systems, is discussed.     

COLIN: A Cache-Conscious Dynamic Learned Index with High Read/Write Performance

The recently proposed learned index has higher query performance and space efficiency than the conventional B+-tree. However, the original learned index has the problems of insertion failure and unbounded query complexity, meaning that it supports neither insertions nor bounded query complexity. Some variants of the learned index use an out-of-place strategy and a bottom-up build strategy to accelerate insertions and support bounded query complexity, but introduce additional query costs and frequent node splitting operations. Moreover, none of the existing learned indices are cache-friendly. In this paper, aiming to not only support efficient queries and insertions but also offer bounded query complexity, we propose a new learned index called COLIN (Cache-cOnscious Learned INdex). Unlike previous solutions using an out-of-place strategy, COLIN adopts an in-place approach to support insertions and reserves some empty slots in a node to optimize the node's data placement. In particular, through model-based data placement and cache-conscious data layout, COLIN decouples the local-search boundary from the maximum error of the model. The experimental results on five workloads and three datasets show that COLIN achieves the best read/write performance among all compared indices and outperforms the second best index by 18.4％, 6.2％, and 32.9％on the three datasets, respectively.     

Performance Analysis of CSMA/CA Protocol for High-speed Wireless LANs

In this paper, we present an exact analysis to numerically evaluate the performance of the multiple random access method with non-persistent carrier sense multiple access with collision-avoidance (CSMA/CA) protocol for high-speed and realizing fully-distributed wireless LANs. The collision-avoidance portion of CSMA/CA in this model is performed with a random pulse transmission procedure, in which a user with a packet ready to transmit initially sends some pulse signals with random intervals within a collision-avoidance period before transmitting the packet to verify a clear channel. The system model consists of a finite number of users to efficiently share a common channel. The time axis is slotted, and a time frame has a large number of slots and includes two parts: the collision-avoidance period and the packet-transmission period. A discrete-time Markov process is used to model the system operation. The number of slots in a frame can be arbitrary, dependent on the chosen lengths of the collision-avoidance period and packet-transmission period. The influence of possible length of the collision-avoidance period and packet-transmission period, and pulse transmission probabilities on the network performance are discussed, based on the results of the utilization of channel and average packet delay for the different packet generation rate.     

融合遗传算法与XGBoost的玉米百粒重相关基因挖掘

基于RNA-Seq的转录组测序数据特征维度较高,使用传统生信方法寻找表型相关基因需要大量计算资源,且差异分析所得候选基因范围较大,进一步筛选依赖已有的先验知识.针对这一问题,本文提出了融合遗传算法和XGBoost的转录组分析方法—GA-XGBoost,通过融入机器学习算法缩小了后续分析的候选基因范围.在一组高质量玉米数...     

IP存储广域网的I/O响应时间分析

以往对网络存储系统的性能分析大都集中在定性研究,定量分析模型很少。在分析基于iSCSI协议的IP存储广域网(IP-SWAN)的数据传输流程的基础上,建立了该系统的Petri网模型。利用Petri网模型的特点,在理论上计算了IP-SWAN系统的I/O响应时间,并分析了各参数对系统性能的影响,提出了改进IP-SWAN系统性能的方法。     

基于PME重尾分布服务时间的M/G/1模型排队性能研究

通信网络的业务源普遍存在着白相似性（或称为长相关性）,传统的假定业务到达间隔服从负指数分布的Poisson模型或其改进形式已不再适用．但在利用M／G／1模型对白相似业务源进行排队分析时,由于重尾分布服务时间的LST变换无闭合形式,进行排队性能分析非常困难．该文通过引入一类混合指数分布证明此类分布服从Pareto重尾分布,并得到相应的LST变换闭合形式及服务时间渐进级数,同时将形状参数y=3／2时的服务时间及其LST变换推广到更一般的情形,从而较为有效地解决了重尾分布的信源排队等待时间分析问题．     

The implementation and evaluation of the use of CORBA in an engineering design application

Many computer applications today require some form of distributed computing to allow different software components to communicate. Several different commercial products now exist based on the Common Object Request Broker Architecture (CORBA) of the Object Management Group. The use of such tools, however, often requires the modification of existing systems, rather than the development of new applications. The objective of this research has been to integrate the use of a CORBA tool into an existing engineering design application for the purpose of (1) evaluating the amount of re‐engineering that is involved to effectively integrate distributed object computing into an existing application, and (2) evaluating the use and performance of distributed object computing in an engineering domain, which often requires the transfer of large amounts of information. The results of this work demonstrate that CORBA technology can be easily integrated into existing applications. The ease of the integration as well as the efficiency of the resulting system, however, depends upon the degree of modification that developers are willing to consider in the re‐engineering process. The most transparent approach to the use of CORBA requires less modification and generally produces less efficient performance. The less transparent approach to the use of CORBA can potentially require significant system modification but produce greater performance gains. This work outlines issues that must be considered for the partitioning of functionality between the client and the server, development of an IDL interface, development of client and server‐side wrappers, and support for concurrent, multi‐user access. In addition, this work also provides performance and implementation comparisons of different techniques for the use of wrappers and for the transfer of large data files between the client and the server. Performance comparisons for the incorporation of concurrent access are also presented. Copyright © 1999 John Wiley & Sons, Ltd.     

Filter Cache:一种提高Lustre I/O性能的方法

高性能计算系统需要一个可靠高效的并行文件系统.Lustre集群文件系统是典型的基于对象存储的集群文件系统,它适合大数据量聚合I/O操作.大文件I/O操作能够达到很高的带宽,但是小文件I/O性能低下.针对导致Lustre的设计中不利于小文件I/O操作的两个方面,提出了Filter Cache方法.在Lustre的OST组件中设计一个存放小文件I/O数据的Cache,让OST端的小文件I/O操作异步进行,以此来减少用户感知的小文件I/O操作完成的时间,提高小文件I/O操作的性能.     

Supporting groups in sorting decisions: Methodology and use of a multi-criteria aggregation/disaggregation DSS

This paper addresses the situation where a group wishes to cooperatively develop a common multicriteria evaluation model to sort actions (projects, candidates) into classes. It is based on an aggregation/disaggregation approach for the ELECTRE TRI method, implemented on the Decision Support System IRIS. We provide a methodology in which the group discusses how to sort some exemplary actions (possibly fictitious ones), instead of discussing what values the model parameters should take. This paper shows how IRIS may be used to help the group to iteratively reach an agreement on how to sort one or a few actions at a time, preserving the consistency of these sorting examples both at the individual level and at the collective level. The computation of information that may guide the discussion among the group members is also suggested. We provide an illustrative example and discuss some paths for future research motivated by this work.     

带工作休假和工作故障的M/M/1/N排队系统性能分析

本文在可修M/M/1/N排队系统中引入了启动时间、工作休假和工作故障策略.在该系统中,服务台在休假期间不是完全停止工作,而是处于低速服务状态.设定服务台在任何时候均可发生故障,当故障发生时立刻进行维修.且当服务台在正规忙期出现故障时,服务台仍以较低的服务速率为顾客服务.服务台的寿命时间和修理时间均服从指数分布,且在不同...     

带启动时间和工作故障的M/M/1/N排队系统性能分析

在M/M/1/N可修排队系统中引入了工作故障和启动时间.服务台在忙期允许出现故障,且在故障期间不是完全停止服务而是以较低的服务速率为顾客服务.同时,从关闭期到正规忙期有服从指数分布的启动时间.通过分析此模型的二维连续时间Markov过程,求解出系统平稳方程,建立此系统的有限状态拟生灭过程(QBD).根据系统参数,求解出水平相依的子率阵,从而得到系统稳态概率向量的矩阵几何表示形式.在系统稳态概率向量的基础上,求解出系统吞吐率、系统稳态可用度、系统稳态队长及系统处于各个状态的概率等性能指标的解析表达式.文中的敏感性分析体现了这种方法的有效性和可用性,同时,对系统各性能受系统参数的影响进行了探索.实验表明,文中提出模型的稳定性较好,且更贴近实际服务过程,因此这种模型将被广泛应用于各种实际服务中.