scholarly journals A Workload-Adaptive and Reconfigurable Bus Architecture for Multicore Processors

2010 ◽  
Vol 2010 ◽  
pp. 1-22 ◽  
Author(s):  
Shoaib Akram ◽  
Alexandros Papakonstantinou ◽  
Rakesh Kumar ◽  
Deming Chen

Interconnection networks for multicore processors are traditionally designed to serve a diversity of workloads. However, different workloads or even different execution phases of the same workload may benefit from different interconnect configurations. In this paper, we first motivate the need for workload-adaptive interconnection networks. Subsequently, we describe an interconnection network framework based on reconfigurable switches for use in medium-scale (up to 32 cores) shared memory multicore processors. Our cost-effective reconfigurable interconnection network is implemented on a traditional shared bus interconnect with snoopy-based coherence, and it enables improved multicore performance. The proposed interconnect architecture distributes the cores of the processor into clusters with reconfigurable logic between clusters to support workload-adaptive policies for inter-cluster communication. Our interconnection scheme is complemented by interconnect-aware scheduling and additional interconnect optimizations which help boost the performance of multiprogramming and multithreaded workloads. We provide experimental results that show that the overall throughput of multiprogramming workloads (consisting of two and four programs) can be improved by up to 60% with our configurable bus architecture. Similar gains can be achieved also for multithreaded applications as shown by further experiments. Finally, we present the performance sensitivity of the proposed interconnect architecture on shared memory bandwidth availability.

2003 ◽  
Vol 04 (01) ◽  
pp. 77-102 ◽  
Author(s):  
CONSTANTINE KATSINIS

Due to advances in fiber-optics and VLSI technology, interconnection networks which allow multiple simultaneous broadcasts are becoming feasible. This paper examines the performance of distributed-shared-memory (DSM) systems based on the Simultaneous Optical Multiprocessor Exchange Bus (SOME-Bus) using queuing network models and develops theoretical results which predict processor utilization, message latency and other useful measures. It also presents simulation results which compare the performance of the SOME-Bus, the mesh and the torus using queuing-network models. The SOME-Bus is a low-latency, high-bandwidth, fiber-optic interconnection network which directly links arbitrary pairs of processor nodes without contention, and can efficiently interconnect over one hundred nodes. It contains a dedicated channel for the data output of each node, eliminating the need for global arbitration and providing bandwidth that scales directly with the number of nodes in the system. Each of the N nodes has an array of receivers, with one receiver dedicated to each node output channel. No node is ever blocked from transmitting by another transmitter or due to contention for shared switching logic. The entire N-receiver array can be integrated on a single chip at a comparatively minor cost resulting in o(N) complexity. The SOME-Bus has much more functionality than a crossbar by supporting multiple simultaneous broadcasts of messages, allowing cache consistency protocols to complete much faster. The effect of collective communications due to cache coherence is examined. Results reveal that the performance of the SOME-Bus interconnection network is the least affected by large communication times, compared to the other two architectures considered here. Even in the presence of intense coherence traffic, processor utilization and message latency is much less affected than in the other architectures.


2017 ◽  
Vol 17 (02) ◽  
pp. 1750005 ◽  
Author(s):  
GAURAV KHANNA ◽  
RAJESH MISHRA ◽  
S. K. CHATURVEDI

Advancement in technology has resulted in increased computing power with the use of multiple processors within a system. These multiple processors need to communicate with each other and with memory modules. Multistage Interconnection Networks (MINs) provide a communication medium in such multi-processor systems by interconnecting a number of processors and memory modules. Besides, MINs also provide a cost effective substitute to costly crossbars in parallel computers and switching systems in telephone industry. This paper introduces two new fault-tolerant MINs named as Shuffle Exchange Gamma Interconnection Networks (SEGIN-1 and SEGIN-2). SEGIN-1 and SEGIN-2 can be obtained by altering Shuffle Exchange Network with one extra stage (SEN+) and provide two disjoint paths similar to it. Performance of SEGIN-1 and SEGIN-2 has been evaluated in terms of alternative paths, disjoint paths, reliability and hardware cost, and is compared with some very famous MINs like Shuffle Exchange Network (SEN), Shuffle Exchange Network with one extra stage (SEN+), Shuffle Exchange Network with two extra stage (SEN+2), Extra Stage Cube (ESC) and Gamma Interconnection Network (GIN). Results suggest that SEGINs surpass all the compared networks; hence, the proposed designs seem to be suitable for implementing practical interconnection networks.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rachael Mooney ◽  
Wafa Abidi ◽  
Jennifer Batalla-Covello ◽  
Hoi Wa Ngai ◽  
Caitlyn Hyde ◽  
...  

Abstract Background Immortalized, clonal HB1.F3.CD21 human neural stem/progenitor cells (NSCs), loaded with therapeutic cargo prior to intraperitoneal (IP) injection, have been shown to improve the delivery and efficacy of therapeutic agents in pre-clinical models of stage III ovarian cancer. In previous studies, the distribution and efficacy of the NSC-delivered cargo has been examined; however, the fate of the NSCs has not yet been explored. Methods To monitor NSC tropism, we used an unconventional method of quantifying endocytosed gold nanorods to overcome the weaknesses of existing cell-tracking technologies. Results Here, we report efficient tumor tropism of HB1.F3.CD21 NSCs, showing that they primarily distribute to the tumor stroma surrounding individual tumor foci within 3 h after injection, reaching up to 95% of IP metastases without localizing to healthy tissue. Furthermore, we demonstrate that these NSCs are non-tumorigenic and non-immunogenic within the peritoneal setting. Conclusions Their efficient tropism, combined with their promising clinical safety features and potential for cost-effective scale-up, positions this NSC line as a practical, off-the-shelf platform to improve the delivery of a myriad of peritoneal cancer therapeutics.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 290
Author(s):  
Chih-Yu Cheng ◽  
Chia-Huang Tsai ◽  
Pei-Jyun Liou ◽  
Chi-Hang Wang

For pilot-scale production of chito-oligosaccharides, it must be cost-effective to prepare designable recombinant chitosanase. Herein, an efficient method for preparing recombinant Bacillus chitosanase from Escherichia coli by elimination of undesirable substances as a precipitate is proposed. After an optimized culture with IPTG (Isopropyl β-d-1-thiogalactopyranoside) induction, the harvested cells were resuspended, disrupted by sonication, divided by selective precipitation, and stored using the same solution conditions. Several factors involved in these procedures, including ion types, ionic concentration, pH, and bacterial cell density, were examined. The optimal conditions were inferred to be pH = 4.5, 300 mM sodium dihydrogen phosphate, and cell density below 1011 cells/mL. Finally, recombinant chitosanase was purified to >70% homogeneity with an activity recovery and enzyme yield of 90% and 106 mg/L, respectively. When 10 L of 5% chitosan was hydrolyzed with 2500 units of chitosanase at ambient temperature for 72 h, hydrolyzed products having molar masses of 833 ± 222 g/mol with multiple degrees of polymerization (chito-dimer to tetramer) were obtained. This work provided an economical and eco-friendly preparation of recombinant chitosanase to scale up the hydrolysis of chitosan towards tailored oligosaccharides in the near future.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3137
Author(s):  
Shuguang Guan ◽  
Qiaoli Pu ◽  
Yinan Liu ◽  
Honghong Wu ◽  
Wenbo Yu ◽  
...  

Crocins are highly valuable natural compounds for treating human disorders, and they are also high-end spices and colorants in the food industry. Due to the limitation of obtaining this type of highly polar compound, the commercial prices of crocins I and II are expensive. In this study, macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was used to purify crocins I and II from natural sources. With only two chromatographic steps, both compounds were simultaneously isolated from the dry fruit of Gardenia jasminoides, which is a cheap herbal medicine distributed in a number of countries. In an effort to shorten the isolation time and reduce solvent usage, forward and reverse rotations were successively utilized in the HSCCC isolation procedure. Crocins I and II were simultaneously obtained from a herbal resource with high recoveries of 0.5% and 0.1%, respectively, and high purities of 98.7% and 99.1%, respectively, by HPLC analysis. The optimized preparation method was proven to be highly efficient, convenient, and cost-effective. Crocins I and II exhibited inhibitory activity against ATP citrate lyase, and their IC50 values were determined to be 36.3 ± 6.24 and 29.7 ± 7.41 μM, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alisa Alekseenko ◽  
Donal Barrett ◽  
Yerma Pareja-Sanchez ◽  
Rebecca J. Howard ◽  
Emilia Strandback ◽  
...  

AbstractRT-LAMP detection of SARS-CoV-2 has been shown to be a valuable approach to scale up COVID-19 diagnostics and thus contribute to limiting the spread of the disease. Here we present the optimization of highly cost-effective in-house produced enzymes, and we benchmark their performance against commercial alternatives. We explore the compatibility between multiple DNA polymerases with high strand-displacement activity and thermostable reverse transcriptases required for RT-LAMP. We optimize reaction conditions and demonstrate their applicability using both synthetic RNA and clinical patient samples. Finally, we validate the optimized RT-LAMP assay for the detection of SARS-CoV-2 in unextracted heat-inactivated nasopharyngeal samples from 184 patients. We anticipate that optimized and affordable reagents for RT-LAMP will facilitate the expansion of SARS-CoV-2 testing globally, especially in sites and settings where the need for large scale testing cannot be met by commercial alternatives.


2021 ◽  
Author(s):  
Karthik K ◽  
Sudarson Jena ◽  
Venu Gopal T

Abstract A Multiprocessor is a system with at least two processing units sharing access to memory. The principle goal of utilizing a multiprocessor is to process the undertakings all the while and support the system’s performance. An Interconnection Network interfaces the various handling units and enormously impacts the exhibition of the whole framework. Interconnection Networks, also known as Multi-stage Interconnection Networks, are node-to-node links in which each node may be a single processor or a group of processors. These links transfer information from one processor to the next or from the processor to the memory, allowing the task to be isolated and measured equally. Hypercube systems are a kind of system geography used to interconnect various processors with memory modules and precisely course the information. Hypercube systems comprise of 2n nodes. Any Hypercube can be thought of as a graph with nodes and edges, where a node represents a processing unit and an edge represents a connection between the processors to transmit. Degree, Speed, Node coverage, Connectivity, Diameter, Reliability, Packet loss, Network cost, and so on are some of the different system scales that can be used to measure the performance of Interconnection Networks. A portion of the variations of Hypercube Interconnection Networks include Hypercube Network, Folded Hypercube Network, Multiple Reduced Hypercube Network, Multiply Twisted Cube, Recursive Circulant, Exchanged Crossed Cube Network, Half Hypercube Network, and so forth. This work assesses the performing capability of different variations of Hypercube Interconnection Networks. A group of properties is recognized and a weight metric is structured utilizing the distinguished properties to assess the performance exhibition. Utilizing this weight metric, the performance of considered variations of Hypercube Interconnection Networks is evaluated and summed up to recognize the effective variant. A compact survey of a portion of the variations of Hypercube systems, geographies, execution measurements, and assessment of the presentation are examined in this paper. Degree and Diameter are considered to ascertain the Network cost. On the off chance that Network Cost is considered as the measurement to assess the exhibition, Multiple Reduced Hypercube stands ideal with its lower cost. Notwithstanding it, on the off chance that we think about some other properties/ scales/metrics to assess the performance, any variant other than MRH may show considerably more ideal execution. The considered properties probably won't be ideally adequate to assess the effective performance of Hypercube variations in all respects. On the off chance that a sensibly decent number of properties are utilized to assess the presentation, a proficient variation of Hypercube Interconnection Network can be distinguished for a wide scope of uses. This is the inspiration to do this research work.


2002 ◽  
Vol 03 (01n02) ◽  
pp. 49-65 ◽  
Author(s):  
NADER F. MIR

A thorough routing analysis of a switching network called the spherical switching network for high-speed applications is presented in this paper. The spherical switching network has a cyclic, regular, and highly expandable structure with a simple self-routing scheme. The network is constructed with fixed-size switch elements regardless of the size of the network. Each switch element consists of a carefully-selected sized 9 input/output crossbar and a local controller. One of the nine pairs of links is external and carries the external traffic, and the other eight pairs are internal. The contention resolution in each switch element is based on deflection of losing packets and incremental priority of packets. The switch elements do not utilize any buffering within the network. The analysis shows that this network clearly outperforms typical interconnection networks currently being deployed in practical switches and routers such as Banyan network. In order to keep the number of deflections low, each incoming external link is connected to a buffer with flow control capabilities. Due to the special arrangement of interconnections in the network, a much larger number of shortest paths between each pair of source/destination exists. The related analysis for finding the number of hops and shortest paths appear in this paper.


2005 ◽  
Vol 18 (2) ◽  
pp. 219-224
Author(s):  
Emina Milovanovic ◽  
Natalija Stojanovic

Because many universities lack the funds to purchase expensive parallel computers, cost effective alternatives are needed to teach students about parallel processing. Free software is available to support the three major paradigms of parallel computing. Parallaxis is a sophisticated SIMD simulator which runs on a variety of platforms.jBACI shared memory simulator supports the MIMD model of computing with a common shared memory. PVM and MPI allow students to treat a network of workstations as a message passing MIMD multicomputer with distributed memory. Each of this software tools can be used in a variety of courses to give students experience with parallel algorithms.


Author(s):  
Behnaz Nowrouzi ◽  
Rachel Li ◽  
Laura E. Walls ◽  
Leopold d’Espaux ◽  
Koray Malci ◽  
...  

AbstractCost-effective production of the highly effective anti-cancer drug, paclitaxel (Taxol®), remains limited despite growing global demands. Low yields of the critical taxadiene precursor remains a key bottleneck in microbial production. In this study, the key challenge of poor taxadiene synthase (TASY) solubility in S. cerevisiae was revealed, and the strains were strategically engineered to relieve this bottleneck. Multi-copy chromosomal integration of TASY harbouring a selection of fusion solubility tags improved taxadiene titres 22-fold, up to 57 ± 3 mg/L at 30 °C at shake flask scale. The scalability of the process was highlighted through achieving similar titres during scale up to 25 mL and 250 mL in shake flask and bioreactor cultivations, respectively. Maximum taxadiene titres of 129 ± 15 mg/L and 119 mg/L were achieved through shake flask and bioreactor cultivation, respectively, of the optimal strain at a reduced temperature of 20 °C. The results highlight the positive effect of coupling molecular biology tools with bioprocess variable optimisation on synthetic pathway development.HighlightsMaximum taxadiene titre of 129 ± 15 mg/L in Saccharomyces cerevisiae at 20 °CIntegrating fusion protein tagged-taxadiene synthase improved taxadiene titre.Consistent taxadiene titres were achieved at the micro-and mini-bioreactor scales.


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