Hierarchical directory-based shared memory architecture

We describe the design of a directory-based shared memory architecture on a hierarchical network of hypercubes. The distributed directory scheme comprises two separate hierarchical networks for handling cache requests and transfers. Further, the scheme assumes a single address space and each processing element views the entire network as contiguous memory space. The size of individual directories stored at each node of the network remains constant throughout the network. Although the size of the directory increases with the network size, the architecture is scalable. The results of the analytical studies demonstrate superior performance characteristics of our scheme compared with those of other schemes.

Gang scheduling with a queue for large jobs

Applying gang scheduling can alleviate the blockade problem caused by exclusively space-sharing scheduling. To simply allow jobs to run simultaneously on the same processors as in conventional gang scheduling, however, may introduce a large number of time slots in the system. In consequence the cost of context switches will be greatly increased, and each running job can only obtain a small portion of resources including memory space and processor utilisation and so no jobs can finish their computations quickly. Therefore, the number of jobs allowed to run in the system should be limited. In this paper we present some experimental results to show that by limiting real large jobs time-sharing the same processors and applying the backfilling technique we can greatly reduce the average number of time slots in the system and significantly improve the performance of both small and large jobs.

On the development of an efficient coscheduling system

Applying gang scheduling can alleviate the blockade problem caused by exclusively space-sharing scheduling. To simply allow jobs to run simultaneously on the same processors as in the conventional gang scheduling, however, may introduce a large number of time slots in the system. In consequence the cost of context switches will be greatly increased, and each running job can only obtain a small portion of resources including memory space and processor utilisation and so no jobs can finish their computations quickly. In this paper we present some experimental results to show that to properly divide jobs into different classes and to apply different scheduling strategies to jobs of different classes can greatly reduce the average number of time slots in the system and significantly improve the performance in terms of average slowdown.

Solving the median shortest path problem in the planning and design of urban transportation networks using a vector labeling algorithm

This paper proposes an alternative algorithm to solve the median shortest path problem (MSPP) in the planning and design of urban transportation networks. The proposed vector labeling algorithm is based on the labeling of each node in terms of a multiple and conflicting vector of objectives which deletes cyclic, infeasible and extreme-dominated paths in the criteria space imposing cyclic break (CB), path cost constraint (PCC) and access cost parameter (ACP) respectively. The output of the algorithm is a set of Pareto optimal paths (POP) with an objective vector from predetermined origin to destination nodes. Thus, this paper formulates an algorithm to identify a non-inferior solution set of POP based on a non-dominated set of objective vectors that leaves the ultimate decision to decision-makers. A numerical experiment is conducted using an artificial transportation network in order to validate and compare results. Sensitivity analysis has shown that the proposed algorithm is more efficient and advantageous over existing solutions in terms of computing execution time and memory space used.

Inter-Frame Change Directing online clustering of multiple moving objects for video-based sensor networks

Recognition of multiple moving objects is a very important task for achieving user-cared knowledge to send to the base station in wireless video-based sensor networks. However, video based sensor nodes, which have constrained resources and produce huge amount of video streams continuously, bring a challenge to segment multiple moving objects from the video stream online. Traditional efficient clustering algorithms such as DBSCAN cannot run time-efficiently and even fail to run on limited memory space on sensor nodes, because the number of pixel points is too huge. This paper provides a novel algorithm named Inter-Frame Change Directing Online clustering (IFCDO clustering) for segmenting multiple moving objects from video stream on sensor nodes. IFCDO clustering only needs to group inter-frame different pixels, thus it reduces both space and time complexity while achieves robust clusters the same as DBSCAN. Experiment results show IFCDO clustering excels DBSCAN in terms of both time and space efficiency. © 2008 IEEE.

Enchanting David Bowie space/time/body/memory

This exciting collection is organized according to the key themes of space, time, body, and memory - themes that literally and metaphorically address the key questions and intensities of his output.

Representing traumatic space

This presentation will begin by the screening of Traum a Dream (2003, 7 mins, Digital Video, Sound)

A representation of traumatised space, depicting a person who is consumed by a body of pain, consumed by fire. Slowly something is remembered (Festival Catalogue: Transmediale.03. February 2003).

The screening will allow a discussion of some of the material embedded in and ideas used in the film's construction. This includes Atwood's view of the colony as victim, Peter pan and never-never-land, Kroker's concept of the panicked body as it relates to the cinema of Mike Hoolboom's hyper-collage and also the use of the abstract and repetition to depict the process of remembering, re-ordering and forgetting. It is also suggested that Random Access Memory as a method of information storage in Digital Media can provide a model for the architecture of traumatised space and Post Traumatic Stress Disorder.

Processing and mechanical properties of porous titanium-niobium shape memory alloy for biomedical applications

Ti-26 at.%Nb (hereafter Ti-26Nb) alloy foams were fabricated by space-holder sintering process. The porous structures of the foams were characterized by scanning electron microscopy (SEM). The mechanical properties of the Ti-26Nb foam samples were investigated using compressive test. Results indicate that mechanical properties of Ti-26Nb foam samples are influenced by foam porosity. The plateau stresses and elastic moduli of the foams under compression decrease with the increase of their porosities. The plateau stresses and elastic moduli are measured to be from 10~200 MPa and 0.4~5.0 GPa for the Ti-26Nb foam samples with porosities ranged from 80~50 %, respectively.

TiNi shape memory alloy foams synthesized by spacer sintering and their properties

Titanium (Ti) and nickel (Ni) elemental powders were blened by ball milling and the ball milled powders were employed to fabricate NiNi shape memory alloy (SMA) foams by space sintering. Effect of ball milling time on phase constitutes of the sintered TiNi alloy foams was studied by X-ray diffraction (XRD) analysis.Scanning election microscopy (SEM) was used to characterize the porous structure, and compressive tests were carried out to evaluate the mechanical properties of the foams. Results indicate the porosities of the TiNi alloy foams can be controlled by using the spacer sincering method, and the porosities show a significant effect on the mechanical prperties and shape memory effect (SME).

Titanium–nickel shape memory alloy foams for bone tissue engineering

Titanium–nickel (TiNi) shape memory alloy (SMA) foams with an open-cell porous structure were fabricated by space-holder sintering process and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The mechanical properties and shape memory properties of the TiNi foam samples were investigated using compressive test. Results indicate that the plateau stresses and elastic moduli of the foams under compression decrease with the increase of their porosities. The plateau stresses and elastic moduli are measured to be from 1.9 to 38.3 MPa and from 30 to 860 MPa for the TiNi foam samples with porosities ranged from 71% to 87%, respectively. The mechanical properties of the TiNi alloy foams can be tailored to match those of bone. The TiNi alloy foams exhibit shape memory effect (SME), and it is found that the recoverable strain due to SME decreases with the increase of foam porosity.

Testimony and memory : re-writeable video memoirs

In Chris Marker’s Sunless (1985), the narrator states: “We do not remember, we re-write memory much as history is rewritten.” This presentation considers the ways in which my parents’ stories have been (and can be) re-written. In 1996, my father and mother engaged in a process of remembering, narrating and re-considering their histories when their video testimonies were recorded for the Survivors of the Shoah Visual History Foundation. They experienced much of World War II in different locations – only re-united after many months. For these video testimonies, they were recorded separately – once again, with a distance of many months between. Whenever there is an attempt to protect a story from interruption and contradiction, narrative multiplicity arises. By comparing and analysing their separate stories in terms of what was said, what was not said, what was unspeakable, and what was unknowable, I am interested in the uncertainties, the gaps, and the different ways in which they attempted to re-make their own histories whilst in the midst of storytelling. I am also interested in re-editing these memoirs into a multi-perspectival family video album, in which the stories and storytellers re-inhabit a shared and re-writeable space of storytelling.

Titanium-based shape memory alloys and scaffolds for biomedical applications

Porous Ti-50.5Ni shape memory alloys with different porosities were produced using a space-holder sintering method. A new Ni-free Ti-based shape memory alloy, Ti-18Nb-5Mo-5Sn, was developed for potential biomedical applications, and a novel one-step hydrothermal process was applied to produce hydroxyapatite coatings on the surface of Ti alloy.

On memory, affect and atonement : the Long Tan memorial cross(es)

This article analyses the history of the Long Tan Memorial in Vietnam in order to open up a space for engaging with the memorialisation of war as something that can go beyond nationalistic sentimentality and create a space for more complex political and social engagements. In doing so I am concerned with exploring the value of an approach to heritage significance that prioritises relationships between places and peoples rather than authenticity and originality. I explore this question by making use of the fact that the Australian War Memorial has borrowed the original Long Tan Cross now in the custodianship of the Dong Nai Museum for a special exhibition to commemorate the Vietnam War. The Australian Vietnam Volunteers Reconstruction Group, who has official custodianship of the replica cross at the Long Tan Memorial site in Vietnam, has expressed disquiet over the loan. I use the Acting Director’s reply to the AVVRG’s Chairman to open up a discussion about the differences in meanings between these two crosses, what underlies these and how we might theorise them in order to open up an understanding of war heritage that recognises its potentials and its limitations.