Gerald Q. Maguire

A class of mobile motion prediction algorithms for wireless mobile computing and communication

This paper describes a class of novel mobile motion prediction algorithms for supporting global mobile data accessing. Traditionally, mobility and routing management includes functions to passively keep track of the location of the users/terminals and to maintain connections to the terminals belonging to the system. To maintain uninterrupted high-quality service for distributed applications, it is important that a mobile system be more intelligent and can anticipate the change of the location of its user. We propose an aggressive mobility and routing management scheme, called predictive mobility management. A class of mobile motion prediction algorithms predicts the “future” location of a mobile user according to the users movement history, i.e., previous movement patterns. By combining this scheme with mobility agent functions, the service and user routing data are actually pre-connected and pre-assigned at the locations to which the user is moving. Thus, the user can immediately receive service or data with virtually the same efficiency as at the previous location, i.e., without encountering a large “data structure handover” delay before service or data is available.

A mobile virtual-distributed system architecture for supporting wireless mobile computing and communications

This paper describes a novel mobile virtual-distrubuted system architecture for supporting global mobile computing and communications. the principal contribution of this paper is to innovatively apply virtual memory concepts to mobile systems by deploying mobile-floating agents to de-couple services and resources from the underlying network and allow them to move around following their mobile users. The mobile-floating agents maintain data structures associated with a mobile user. By combining the mobile-floating agent functions with a predictive mobility management algorithm and location-aware caching and prefetching, services and user data structure are pre-connected and pre-assigned at the locations to which the user is moving. Thus, the users can maintain their data structures or immediately receive service with virtually the same efficiency as at the previous location.

Genetic Algorithm Based Feature Selection Algorithm for Effective Intrusion Detection in Cloud Networks

Cloud computing is expected to provide on-demand, agile, and elastic services. Cloud networking extends cloud computing by providing virtualized networking functionalities and allows various optimizations, for example to reduce latency while increasing flexibility in the placement, movement, and interconnection of these virtual resources. However, this approach introduces new security challenges. In this paper, we propose a new intrusion detection model in which we combine a newly proposed genetic based feature selection algorithm and an existing Fuzzy Support Vector Machines (SVM) for effective classification as a solution. The feature selection reduces the number of features by removing unimportant features, hence reducing runtime. Moreover, when the Fuzzy SVM classifier is used with the reduced feature set, it improves the detection accuracy. Experimental results of the proposed combination of feature selection and classification model detects anomalies with a low false alarm rate and a high detection rate when tested with the KDD Cup 99 data set.

Role(s) of a proxy in location based services

We examine a number of roles that a proxy server can play in location based services and how it can be used to provide protection of personal identifiable information. Location data, service requests, and privacy policies are encoded in XML by the mobile terminal and forwarded to a proxy server placed between the mobile terminal and the location based service(s). By a suitable architecture in the mobile terminal and in the proxy, we can hide the mobile devices network location, hide the identity of its user, and, in some cases, provide misleading physical location(s). We have applied our privacy model to location information obtained from a GPS receiver. The GPS-based method was chosen as being the only available method where the positioning calculation function (PCF) is fully under the users control, since the position is calculated within the mobile terminal; other technologies rely on the network infrastructure, and hence some or all of the position data is outside the users control. A proof of concept was implemented using Fastraxs iTrax02 small, ultra-low power consumption GPS receiver. We illustrate a number of different functions which can be provided by examining some scenarios.

A multiport mobile internet-router

In the Swedish Walkstation project a device for mobile hosts and base stations is realized by the same kind of hardware but with different kinds of communication software. This device, called MINT (Mobile IP Router), consists mainly of three parts, one for the connection to the host or backbone net (Ethernet), one for connecting to wireless LANs (radio or infrared), and a processing part for computing the communication protocols. This device serves as more than a mobile modem, i.e., it actually routes packets over potentially multiple paths with varying connectivity and quality. By using Ethernet as an input channel, it should not be necessary to install special purpose wiring dedicated to mobile communication. Instead the existing network, which normally is globally available, is used to select suitable sites for base stations. To realize a large scale field trial the new router must be low cost, small in size, and have a low power consumption while offering high performance. The current phase of the project involves building a 68030 based router with multiple interfaces, including as host interfaces: SCSI, Ethernet, serial, parallel; and as wireless interfaces: IR, microwave-radio, or a-second Ethernet (supported for software development).<<ETX>>

Evaluation of mobility and stability in the Discover artificial disc: an in vivo motion study using high-accuracy 3D CT data

OBJECT Artificial disc replacement (ADR) devices are unlike implants used in cervical fusion in that they are continuously exposed to stress not only within the implant site but also at their site of attachment to the adjacent vertebra. An imaging technique with higher accuracy than plain radiography and with the possibility of 3D visualization would provide more detailed information about the motion quality and stability of the implant in relation to the vertebrae. Such high-accuracy studies have previously been conducted with radiostereometric analysis (RSA), which requires implantation of tantalum markers in the adjacent vertebrae. The aim of this study was to evaluate in vivo motion and stability of implanted artificial discs. A noninvasive analysis was performed with CT, with an accuracy higher than that of plain radiographs and almost as high as RSA in cervical spine. METHODS Twenty-eight patients with ADR were included from a larger cohort of a randomized controlled trial comparing treatment of cervical radiculopathy with ADR or anterior cervical decompression and fusion. Surgical levels included C4-7; 18 patients had 1-level surgery and 10 patients had 2-level surgery. Follow-up time ranged from 19 to 50 months, with an average of 40 months. Two CT volumes of the cervical spine, 1 in flexion and 1 in extension, were obtained in each patient and then spatially registered using a customized imaging tool, previously used and validated for the cervical spine. Motion between the components in the artificial disc, as well as motion between the components and adjacent vertebrae, were calculated in 3 planes. Intraclass correlation (ICC) between independent observers and repeatability of the method were also calculated. RESULTS Intrinsic motion, expressed as degrees in rotation and millimeters in translation, was detectable in a majority of the ADRs. In the sagittal plane, in which the flexion/extension was performed, sagittal rotation ranged between 0.2° and 15.8° and translation between 0.0 and 5.5 mm. Eight percent of the ADRs were classified as unstable, as motion between at least 1 of the components and the adjacent vertebra was detected. Five percent were classified as ankylotic, with no detectable motion, and another 8% showed very limited motion due to heterotopic ossification. Repeatability for the motion in the sagittal plane was calculated to be 1.30° for rotation and 1.29 mm for translation (95% confidence level), ICC 0.99 and 0.84, respectively. All 3 patients with unstable devices had undergone 1-level ADRs at C5-6. They all underwent revision surgery due to increased neck pain, and instability was established during the surgery. CONCLUSIONS The majority of the artificial discs in this study showed intrinsic mobility several years after implantation and were also shown to be properly attached. Implant instability was detected in 8% of patients and, as all of these patients underwent revision surgery due to increasing neck pain, this might be a more serious problem than heterotopic bone formation.

A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis

As the most advantageous total hip arthroplasty (THA) operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT) volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD) of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (±SD) for the diameter of the acetabular cup of 54.21 (±0.011) mm and for the femoral component head of 22.09 (±0.02) mm. The wear error was ±0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction.

The Walkstation transceiver design

The design of flexible and efficient future mobile communication systems is a major challenge. The Walkstation Project involves researchers from different areas in order to find a solution via a global system approach. An important task is the investigation of new digital, highly integrated radio interfaces with low cost, small size and low power consumption based on direct sequence CDMA. The simplicity of the design of both the analog and digital parts will allow low power operation and small area in a eventual BiCMOS implementation.<<ETX>>

Can the specificity of MRI breast imaging be improved by fusing 3D MRI volume data sets with FDG PET

MRI of the breast is an important tool for early detection of breast cancer in women at increased risk for tumor. MRI has a proven track record in identifying tissue abnormalities, but often lacks the ability to characterize this tissue abnormality as benign or malignant, i.e., for certain tissue abnormalities the specificity of MRI is very high, while for others it may be 50% or less. This inability of MRI to differentiate between certain types of tissue abnormalities has lead to our interest in exploring whether the fusion of MRI scans with metabolic imaging (PET) scans can be helpful. 18-FDG PET provides information about the metabolism of the tissue in the breast which in tumors is generally increased. This technique is widely used for detection of other forms of cancer, but has not yet been systematically applied to primary breast cancer, although it has been used to detect local recurrence.

Profiling and accelerating commodity NFV service chains with SCC

A tool that can thoroughly profile hot parts of NFV software stacks is proposed.Our profiler revealed I/O and scheduling problems for user-space NFV chains.We solve these problems by combining I/O multiplexing and scheduling techniques.We reduce the latency (by 3x) and latency variance (by 2-40x) of these NFV chains. Recent approaches to network functions virtualization (NFV) have shown that commodity network stacks and drivers struggle to keep up with increasing hardware speed. Despite this, popular cloud networking services still rely on commodity operating systems (OSs) and device drivers. Taking into account the hardware underlying of commodity servers, we built an NFV profiler that tracks the movement of packets across the systems memory hierarchy by collecting key hardware and OS-level performance counters. Leveraging the profilers data, our Service Chain Coordinators (SCC) run-time accelerates user-space NFV service chains, based on commodity drivers. To do so, SCC combines multiplexing of system calls with scheduling strategies, taking time, priority, and processing load into account. By granting longer time quanta to chained network functions (NFs), combined with I/O multiplexing, SCC reduces unnecessary scheduling and I/O overheads, resulting in three-fold latency reduction due to cache and main memory utilization improvements. More importantly, SCC reduces the latency variance of NFV service chains by up to 40x compared to standard FastClick chains by making the average case for an NFV chain to perform as well as the best case. These improvements are possible because of our profilers accuracy.