Aero-Acoustics of Modern Transonic Fans—— Fan Noise Reduction from Its Sources

The noise of aerodynamics nature from modern transonic fan is examined from its sources with the perspective of noise reduction through aero-acoustics design using advanced Computational Fluid Dynamics (CFD) tools. In particular the problems associated with the forward propagating noise in the front is addressed. It is identified that the shock wave spillage from the leading edge near the fan tip is the main source of the tone noise. Two different approaches have been studied to reduce the forward arc tone noise and two state-of-art transonic fans are designed using the strategies developed. The following rig tests show that while the fans exhibit other noise problems, the primary goals of noise reduction have been achieved through both fans and the novel noise reduction concept vindicated.     

Conceptual and Implementation Models for the Grid

The Grid is rapidly emerging as the dominant paradigm for wide area distributed application systems. As a result, there is a need for modeling and analyzing the characteristics and requirements of Grid systems and programming models. This work adopts the well-established body of models for distributed computing systems, which are based upon carefully stated assumptions or axioms, as a basis for defining and characterizing Grids and their programming models and systems. The requirements of programming Grid applications and the resulting requirements on the underlying virtual organizations and virtual machines are investigated. The assumptions underlying some of the programming models and systems currently used for Grid applications are identified and their validity in Grid environments is discussed. A more in-depth analysis of two programming systems, the Imperial College E-Science Networked Infrastructure (ICENI) and Accord, using the proposed definitions' structure is presented.     

SARs are cis DNA elements of chromosome dynamics: synthesis of a SAR repressor protein

SARs are candidate DNA elements for defining the bases of chromatin loops and possibly for serving as cis elements of chromosome dynamics. SARs contain numerous A tracts, whose altered DNA structure is recognized by cooperatively interacting proteins such as topoisomerase II. We constructed multi-AT hook (MATH) proteins and demonstrate that they specifically bind the clustered A tracts of SARs in chromatin and chromosomes. They are also potent inhibitors of chromosome assembly in mitotic Xenopus extracts, demonstrating the importance of SARs in this process. Titration of SARs with MATH20 (20 hooks) blocks shape determination of chromatids but not chromatin condensation per se. SARs are also required for shape maintenance of chromosomes. If MATH20 is added after formation of chromatids, they collapse and are reshaped by an active, mitotic process into spherical chromatid balls.     

Chloroquine, quinine and quinidine inhibit calcium release from macrophage intracellular stores by blocking inositol 1,4,5-trisphosphate binding to its receptor

Endocrine and exocrine pancreatic morphogenesis is known to occur from ductal epithelium, but the factors that regulate this process are unknown. Vascular endothelial growth factor (VEGF)/vascular permeability factor has recently been reported to affect fetal islet ontogenesis. VEGF is an angiogenic factor with a growth-promoting effect that is thought to be restricted to vascular endothelial cells. We demonstrated that VEGF is also a mitogen for adult rat pancreatic duct epithelial cells in primary culture. VEGF supplementation to a serum-free culture medium increased the 5-bromo-2'-deoxyuridine-pulse labeling index of ductal cells more than 2-fold. Immunohistochemical staining and protein blots revealed that pancreatic duct cells express fetal liver kinase-1 high-affinity receptors for VEGF. In pancreatic tissue, immunohistochemistry shows that VEGF peptide is expressed in normal pancreatic islet cells. In duct ligation-induced acute pancreatitis, numerous inflammatory leukocytes containing VEGF were seen to infiltrate between hyperplastic ducts. In the latter model, islet neogenesis has previously been observed. Our data indicate the possibility that VEGF plays a role in the paracrine regulation of ductal growth and differentiation in vivo, eg, in pancreatitis. In vitro, however, VEGF did not induce endocrine differentiation of ductal cells, indicating that it is not the only factor required for the activation of islet neogenesis.     

Hybrid Runtime Management of Space-Time Heterogeneity for Parallel Structured Adaptive Applications

Structured adaptive mesh refinement (SAMR) techniques provide an effective means for dynamically concentrating computational effort and resources to appropriate regions in the application domain. However, due to their dynamism and space-time heterogeneity, scalable parallel implementation of SAMR applications remains a challenge. This paper investigates hybrid runtime management strategies and presents an adaptive hierarchical multipartitioner (AHMP) framework. AHMP dynamically applies multiple partitioners to different regions of the domain, in a hierarchical manner, to match the local requirements of the regions. Key components of the AHMP framework include a segmentation-based clustering algorithm (SBC) that can efficiently identify regions in the domain with relatively homogeneous partitioning requirements, mechanisms for characterizing the partitioning requirements of these regions, and a runtime system for selecting, configuring, and applying the most appropriate partitioner to each region. Further, to address dynamic resource situations for long-running applications, AHMP provides a hybrid partitioning strategy (HPS) that involves application-level pipelining, trading space for time when resources are sufficiently large and underutilized, and an application-level out-of-core strategy (ALOC), trading time for space when resources are scarce in order to enhance the survivability of applications. The AHMP framework has been implemented and experimentally evaluated on up to 1,280 processors of the IBM SP4 cluster at the San Diego Supercomputer Center.     

Energy-Efficient Thermal-Aware Autonomic Management of Virtualized HPC Cloud Infrastructure

Virtualized datacenters and clouds are being increasingly considered for traditional High-Performance Computing (HPC) workloads that have typically targeted Grids and conventional HPC platforms. However, maximizing energy efficiency and utilization of datacenter resources, and minimizing undesired thermal behavior while ensuring application performance and other Quality of Service (QoS) guarantees for HPC applications requires careful consideration of important and extremely challenging tradeoffs. Virtual Machine (VM) migration is one of the most common techniques used to alleviate thermal anomalies (i.e., hotspots) in cloud datacenter servers as it reduces load and, hence, the server utilization. In this article, the benefits of using other techniques such as voltage scaling and pinning (traditionally used for reducing energy consumption) for thermal management over VM migrations are studied in detail. As no single technique is the most efficient to meet temperature/performance optimization goals in all situations, an autonomic approach that performs energy-efficient thermal management while ensuring the QoS delivered to the users is proposed. To address the problem of VM allocation that arises during VM migrations, an innovative application-centric energy-aware strategy for Virtual Machine (VM) allocation is proposed. The proposed strategy ensures high resource utilization and energy efficiency through VM consolidation while satisfying application QoS by exploiting knowledge obtained through application profiling along multiple dimensions (CPU, memory, and network bandwidth utilization). To support our arguments, we present the results obtained from an experimental evaluation on real hardware using HPC workloads under different scenarios.     

正确表面预处理对涂料干膜杀菌剂抗微生物活性的影响

通过使用墙体杀菌清洁与非杀菌清洁后涂料干膜的性能比较，评价了杀菌清洗对提高涂料干膜性能的有效性，揭示了怎样用杀菌清洁提高杀菌系统的特性。同时，比较了传统杀菌剂和新式杀菌剂的性能差别。     

Stability of linear discrete switched systems with delays based on average dwell time method

This paper deals with the problem of exponential stability for a class of linear discrete switched systems with constant delays.The switched systems consist of stable and unstable subsystems.Based on the average dwell time method, some switching signals will be found to guarantee exponential stability of these systems.The explicit state decay estimation is also given in the form of the solutions of linear matrix inequalities(LMIs).An example relating to networked control systems(NCSs) illustrates the effect...     

一类仿射非线性系统的概率密度函数形状控制

针对一类仿射非线性有界动态随机系统,提出一种最优概率密度函数（PDF）跟踪控制算法,使得系统的输出PDF跟踪给定的PDF．首先利用线性B样条解耦得到仿射非线性状态方程和PDF逼近方程,使PDF跟踪转化为状态方程输出权值的跟踪;然后采用线性时变序列逼近方法将非线性系统转化为线性时变系统,通过对线性系统的迭代运算得到非线性系统的最优跟踪控制器,从而实现最优PDF跟踪．理论分析和仿真实验均表明了所提出算法的有效性．     

ISHair: Importance Sampling for Hair Scattering

We present an importance sampling method for the bidirectional scattering distribution function (bsdf) of hair. Our method is based on the multi‐lobe hair scattering model presented by Sadeghi et al. [ [SPJT10] ]. We reduce noise by drawing samples from a distribution that approximates the bsdf well. Our algorithm is efficient and easy to implement, since the sampling process requires only the evaluation of a few analytic functions, with no significant memory overhead or need for precomputation. We tested our method in a research raytracer and a production renderer based on micropolygon rasterization. We show significant improvements for rendering direct illumination using multiple importance sampling and for rendering indirect illumination using path tracing.