computer systems involve increasingly complex hardware components and software abstractions, e.g. an Xen Hypervisor managing virtual machines running on a multi-core CPU. In the industry, computer engineers are asked ...
详细信息
This paper presents extensions to the Linux trace toolkit (LTT) for efficiently tracing complete systems, from the user level to the virtual machine system level and the Xen hypervisor layer. An automated benchmark wa...
详细信息
This paper presents extensions to the Linux trace toolkit (LTT) for efficiently tracing complete systems, from the user level to the virtual machine system level and the Xen hypervisor layer. An automated benchmark was created to measure the overhead imposed by tracing and Xen paravirtualization, comparing the performance of systems, with and without virtualization and tracing. The results show a negligible impact caused by tracing and a reasonable overhead caused by paravirtualization. For some I/O intensive applications, the overhead imposed by paravirtualization is less negligible.
This paper proposes an efficient region-based background subtraction technique using static camera for motion detection in various monitoring applications. Color histograms, texture information, and successive divisio...
详细信息
This paper proposes an efficient region-based background subtraction technique using static camera for motion detection in various monitoring applications. Color histograms, texture information, and successive division of candidate rectangular image regions are utilized to model the background and detect the motion. The proposed method combines this principle and the Gaussian mixture background modeling to produce a new method which out performs the classic Gaussian mixture background subtraction method. It has the advantages of filtering noise during image differentiation and providing a selectable level of detail for the contour of the moving shapes. Results show that our proposed method combined with Gaussian mixture outperforms results obtained with Gaussian mixture alone, particularly in the combination with MDPA distance.
Wireless local area networks (WLANs) are more deployed today than ever before. However, this rapid growth led to uncoordinated deployment and planning tools are rarely used. In this paper, we first propose a mathemati...
详细信息
Wireless local area networks (WLANs) are more deployed today than ever before. However, this rapid growth led to uncoordinated deployment and planning tools are rarely used. In this paper, we first propose a mathematical model to solve the WLAN planning problem considering directional antennas. The problem consists of selecting the location of the access points in the network and selecting the transmit power, the antenna type and its orientation as well as the communication channel of each one. The use of interfering channels is allowed to solve the frequency allocation problem. Since the problem is NP-hard, we propose a two-step tabu-based metaheuristic algorithm to find solutions satisfying a radio coverage constraint, a throughput constraint and an interference level constraint. Our objective is to minimize the cost of the network and to distribute evenly the resources amongst the users. The aim of the first step of the algorithm is to obtain a solution that satisfies all the constraints while the second step focuses on optimizing the previously obtained solution. A new neighborhood, based on radio coverage of an access point, is proposed. The results show that solutions can be obtained with the proposed approach for real-size instances of the problem.
In this paper, we propose a heuristic algorithm based on the tabu search principle for the topological design problem of two-level Internet protocol (IP) networks including the design of the points of presence. This g...
详细信息
In this paper, we propose a heuristic algorithm based on the tabu search principle for the topological design problem of two-level Internet protocol (IP) networks including the design of the points of presence. This global problem consists in selecting the number of routers and their types to install in each point of presence, selecting the interface card types to install in each router, finding the access and backbone networks and finally, interconnecting the co-located routers in each point of presence. The numerical results show that "good" solutions can be found rapidly with the proposed approach.
Body sensor network (BSN) is a wireless network of implantable and/or wearable smart sensors. They can be deployed in medical applications, such as patients monitoring inside or outside hospital environment, as well a...
详细信息
Body sensor network (BSN) is a wireless network of implantable and/or wearable smart sensors. They can be deployed in medical applications, such as patients monitoring inside or outside hospital environment, as well as in high performance professional sports and other non human related applications. The size of a sensor node and its power consumption are major challenges in the design of implantable BSNs. The focus of this paper is to propose the definition of a new light weight communications protocol for the BSNs applications using very small sensor nodes supporting ultra low energy consumption.
Founded in 1999, SSCS-montreal includes over forty SSCS members and hundreds of students, and spans several industrial companies and universities. The co-sponsorship of montreal chapter activities by the Microsystems ...
Founded in 1999, SSCS-montreal includes over forty SSCS members and hundreds of students, and spans several industrial companies and universities. The co-sponsorship of montreal chapter activities by the Microsystems Research Alliance of Quebec (ReSMiQ) has been key in enabling the organization to enjoy a broad range of activities. According to the Chapter's co-chairs, the key for managing an effective SSCS Chapter is to create and sustain enthusiasm for custom solid-state circuits through serving the learning needs of current Chapter members and attracting new members, especially students.
This paper proposes a fast MAC layer handoff scheme with accelerated probe function that reduces handoff latency as well as packet losses in wireless LANs. With this approach, a mobile station (MS) can scan a subset o...
详细信息
ISBN:
(纸本)9780889866591
This paper proposes a fast MAC layer handoff scheme with accelerated probe function that reduces handoff latency as well as packet losses in wireless LANs. With this approach, a mobile station (MS) can scan a subset of all channels when it moves beyond the radio range of its current associated access point (AP). Performance evaluation is done through simulations, and experimental results indicates that our approach has better performance than the standard IEEE 802.11b and two well-cited handoff schemes: selective scanning plus caching and neighbour graphs, in terms of handoff latency, probe delay and packet losses.
A fully-integrated, low-power 1830 MHz voltage-controlled oscillator (VCO) used in the frequency synthesizer of an implantable wireless multisensor microsystem (IWSM) dedicated to in vivo monitoring of biological para...
详细信息
暂无评论