# Faculty & Staff Research

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Item 3-D graphics in APL: user perspective(1988) Gujar, Uday, G.The purpose of this document is to explain how a user can generate and display three dimensional objects in APL. We will not deal with how the system is put together. The top-down approach will be used.Item 3-D solids from 2-D views(1988) Gujar, Uday, G.; Nagendra, I., V.An algorithm to generate three dimensional sold objects, made up of planar surfaces, from the given three conventional engineering orthographic views is presented in this paper. Consisting of six major steps, the algorithm has been programmed in C on IRIS 1400 graphics workstation. The algorithm generates all possible solutions. The infinite space has been divided into finite subspaces by making use of the surface normals and the direction of travel of the edges that connect the faces. Classification of the probable 3-D subobjects into the certain and uncertain ones has proved to be very useful in reducing the time taken by the algorithm. Several illustrative examples, simple as well as complex giving single and multiple solutions, are included.Item 3-D visualization of message passing in distributed programs(1996) Gobrecht, Cyril; Ware, Colin; Bhavsar, Virendrakumar, C.This paper describes PVMtrace, a software system for understanding and debugging message passing in distributed programs. In this system each process is represented as a node in a graph and the arcs represent the potential communication channels. The transfer of a packet of information from one process to another is shown by a bead-like object moving along an arc. A queue is a string of beads lined up waiting to be processed. The flexible control over time is found to be essential for the system to be useful and it allows the animation to be played forward and backwards in time both by the direct manipulation of the time line and by an animation rate controller. In addition there is an automatic time control method that rapidly moves the animation through intervals of low activity while slowing down in periods of high activity. The system was initially developed as a PVM debugging tool but it has also been found to be useful in other areas. In particular it has been used to visualize communications in a cellular phone system.Item A brighter tomorrow: insight into abusive relationships(2004) Merritt-Gray, Marilyn; Wuest, JudithThe purpose of this pamphlet is to provide information that can be used to help people who have experienced partner abuse.Item A case study of the production of an S-57 ENC with CARIS toolsPais, Luis, M.The advent of the Electronic Chart Displaying and Information System (ECDIS) and the availability of an accurate positioning system, such as the Differential Global Positioning System (DGPS), were the driving technologies for a new digital hydrographic product. The Electronic Navigational Chart (ENC) is a new hydrographic product, recognized by the international marine instances as the equivalent of the traditional paper chart. The production of ENCs is being supported by the use of Geographic Information System (GIS) tools to meet the requirements of the International Standard for the Exchange of Hydrographic Data, documented in the IHO special publication No 57 (S-57). The S-57 document makes the use of the object-oriented concept to model the real world into a computer-based format. The aim of this report is to study the production of an ENC with tools from Universal Systems Limited (USL), CARIS and OBMAN, to make recommendations and suggestions not only for software enhancement but also to contribute to the optimization procedures within an Hydrographic Office (HO) currently producing both paper and electronic charts. This report is structured in seven chapters. This first two define the problem of building an ENC within an HO and introduce an historical background to support the discussion between raster and vector charts. The Object-Oriented (O-O) concept in general and its meaning for the S-57 standard, in particular, is described in chapter 3. The use of “dedicated methods” in O-O is particularly important within the S-57 ENC because it allows an object to be displayed with different geometries depending on the scale chosen. The S-57 standard is explained in detail in chapter 4, while chapter 5 introduced the CARIS tools used. Chapter 5 also compares two different ENC viewers (ECVIEW and SeeMyENC!). The steps followed by the author to build an S-57 ENC are also contained in this chapter. An example is the need for an appropriate layering of the data whenever a CARIS file is built for both paper and electronic chart production. The author also suggests a quality control tool to check for inconsistences and distortions on the shapes of the feature objects after the filtering of the point data (S-57 standard).Item A comparison of local and wide area GNSS differential corrections disseminated using the network transort of RTCM via internet protocol (NTRIP)McKessock, GeorgePsuedorange corrections (PRCs) have long been used to improve the accuracy of GNSS solutions in real time. Today, they continue to be useful for sub-metre level requirements, such as when setting ground control for satellite imagery and for en route navigation on land, in the air and at sea. The transmission of these corrections has traditionally been facilitated using either radio or satellite communications. The Networked Transport of RTCM via Internet Protocol (NTRIP) specification takes advantage of the availability of Internet over digital mobile phones to disseminate PRCs. In this report, NTRIP has been used to transmit both localized wide area and local PRC corrections over the Internet to a client receiver where they have been applied. The accuracy of different solutions is compared. In addition, the convergence of different solutions is analyzed. This analysis will enable potential users to determine the position and height accuracy that they can expect to achieve under various scenarios as well as the observation times which they should employ. Results for horizontal positions showed errors at a 95% confidence level to be at the 2-metre level for uncorrected GNSS, 30 cm for GNSS augmented with local corrections generated at UNB and 1.0 m for corrections generated 430 km away. The Canadawide Differential GPS (CDGPS) wide area system produced errors of 60 cm. Results for heights were of a similar order. However, we found that height solutions were significantly more correlated with observation time than were horizontal positions. Our work showed that NTRIP could be used easily to both disseminate and use localized wide area and local differential corrections. We believe that as costs for digital mobile service becomes cheaper and more widely available, NTRIP will become commonly used. In addition, we recommend that the CDGPS service consider supporting NTRIP. Currently, CDGPS has a limited user-base because it is accessible only with the use of receivers containing NovAtel®-based chipsets. We believe that NTRIP can potentially bring CDGPS to a much wider object. Finally, by far, the best position and height accuracies achieved were with the use of local differential corrections. Even when the reference receiver was 430 km from the user receiver, resulting solutions were better in both accuracy and precision than uncorrected solutions. Canada and New Brunswick each operate an Active Control Network, consisting of many continuously operating GNSS receivers that are already connected to the Internet. We believe that with very little effort, this network can be extended, using NTRIP, to disseminate DGNSS corrections.Item A comparison of non-point spatial data indexing methodologies(1990) Xie, LipingThe general objective of this research is to compare the performance of several spatial indexing methods. In order to do so, we built spatial indices for two-dimensional nonzero size objects and performed range searches on those objects. There are two ways to create an index: 1) use the spatial data support in commercially available databases such as Oracle 8i and O2, and 2) create the spatial data-indexing scheme directly using spatial data structures such as the R-tree or Grid file. A new data structure based on the binaryradix bucket-region (BR2) grid file was created for non-point objects. Two sets of data from the National Topological Database were used to perform the experimental comparisons. We performed two different types of range search: search based on the bounding box of the objects only (primary) and search based on the real data (secondary). Testing was performed with query window areas= 1%, 4%, 9%, 16%, 25%, 36%, 49%, 64%, 81%, and I 00% of the data extent. For secondary range search, the R-tree and the modified grid file took the least amount of time (0.497 seconds and 0.628 seconds respectively) on average to report (out of a test set of 20,000 objects) the objects in range for a query window area= 49% of the original data extent. The Oracle 8i Spatial object-relational, and the Oracle 8i Spatial relational methods required, on average, 220, and 400 times more time for the same search, respectively. Significant difficulties were encountered in getting the commercially available databases to perform range searches on the test data.Item A comparison of vectorizable discrete sampling methods in Monte Carlo applications(1995) Sarno, Riyanarto; Bhavsar, Virendra, C.; Hussein, Esam, M., A.The performance of various vectorizable discrete random-sampling methods, along with the commonly used inverse sampling method, is assessed on a vector machine. Monte Carlo applications involving, one-dimensional, two-dimensional and multi-dimensional probability tables are used in the investigation. Various forms of the weighted sampling method and methods that transform the original probability table are examined. It is found that some form of weighted sampling is efficient, when the original probability distribution is not far from uniform or can be approximated analytically. Table transformation methods, though require additional memory storage, are best suited in applications where multi-dimensional tables are involved. Keywords: Discrete sampling, Weighted sampling, Monte Carlo simulations, Vector processing.Item A computer aided design tutorial system (CADETS)(1986) Slipp, Leonard; Gujar, Uday, G.Computer aided design (CAD) systems have proved to be a very valuable toll widely used in industry. These systems are often expensive both from the hardware and software point of view. As such first hand training becomes an expensive proportion especially in an environment where training is the main goal and production a secondary or a minor goal. Such is the case in the educational institutions. This paper describes a two-dimensional Computer Aided Design Tutorial System (CADETS) modelled after Unigraphics I. Written in APL, the system does not demand any knowledge of APL for the user. An IBM 3279 colour graphics terminal is used as a graphics input as well as output device. The screen is divided into five windows. The main, and the largest, window is used for graphics; the others are used for user communication. Menus are used extensively to generate, modify and manipulate the display. Within CADETS, there are currently eleven ways to create a point, thirteen ways to create a line segment, ten ways to specify a circular arc and several functions to generate common geometric objects such as triangles, rectangles, polygons, etc. Once created, the user may edit the graphics model by deleting geometric entities either individually or in a group. Line segments may be extended or trimmed to specified boundaries, constrained to intersect at a corner, etc. Arcs may be extended or truncated so that they would be bound by specified angles or points or lines which intersect them. The visual attributes of any entity may be changed. The user can also control the view area and scale of model thus providing a pan and zoom capability to concentrate on selected areas of the display. An interface has been provided to produce a hardcopy on a variety of devices. The system has been used by several users including high school students who were unaware of even the existence of APL. The system requires minimal investment on hardware as well as software compared to sophisticated expensive systems, yet provides tools for teaching several fundamental CAD techniques. Plans are underway to enhance 2-D capabilities, incorporate other inexpensive graphics devices and include 3-D graphics.Item A coordinated community response to domestic and intimate partner violence experienced by immigrant and newcomer women in new Brunswick - needs assessment report(2016) Holtmann, Catherine; Torri, Maria Costanza; Rickards, Tracey; Matta, CrestinaThis 36 month project aims to improve service responses for immigrant and newcomer women who are victims of domestic and intimate partner violence (D/IPV) in New Brunswick. Through partnerships, a coordinated community response will be developed between provincial government departments, domestic violence support-service providers, immigrant serving organizations and community partners, incorporating the lens of immigrant and newcomer women’s experiences throughout the project. The learnings from this project will be integrated into future provincial strategies to address D/IPV experienced by immigrant and newcomer women.Item A Data Structure for I/O Efficient Search of Objects Moving on a Graph(2009) Le, Thuy, T., T.; Nickerson, Bradford, G.We present a spatio-temporal data structure called minimum I/O Graph Strip Tree (minGStree) to index moving objects on a graph. The minGStree is designed to efficiently answer time instance and time interval queries about the past positions of moving objects. The minGStree uses Θ( n ) blocks of external memory, where n B is the number of moving object instances (unique entries of moving objects) and B is the I/O block size. For n moving object instances randomly distributed on the E edges of a graph over a time domain [0, T ], the expected number of I/Os required to determine the moving objects intersecting one edge (for both time instance queries and time interval queries) in a minGStree is O(logB ( n ) + k), where k is the number E of disk blocks required to store the answer. We anticipate this data structure will be practical to implement.Item A Deep Transfer Learning Approach to Reducing the Effect of Electrode Shift in EMG Pattern Recognition-Based Control(Institute of Electrical and Electronics Engineers, 2020) Ameri, Ali; Akhaee, Mohammad Ali; Scheme, Erik; Englehart, KevinAn important barrier to commercialization of pattern recognition myoelectric control of prostheses is the lack of robustness to confounding factors such as electrode shift, skin impedance variations, and learning effects. To overcome this challenge, a novel supervised adaptation approach based on transfer learning (TL) with convolutional neural networks (CNNs) is proposed which requires only a short training session (a few seconds for each class) to recalibrate the system. TL is proposed as a solution to the problem of insufficient calibration data due to short training times for both classification and regression-based control schemes. This approach was validated for electrode shift of roughly 2.5cm with 13 able-bodied subjects to estimate individual and combined wrist motions. With this method, the original CNN (trained before the shift) was fine-tuned with the calibration data from after shifting. The results show that the proposed technique outperforms training a CNN from scratch (random initialization of weights) or a support vector machine (SVM) using the minimal calibration data. Moreover, it demonstrates superior performance than previous LDA and QDA-based adaptation approaches. As the outcomes confirm, the proposed CNN TL method provides a practical solution for adaptation to external factors, improving the robustness of electromyogram (EMG) pattern recognition systems.Item A device independent computer plotting system(1976) Gujar, Uday, G.Almost every computing centre has a variety of plotting devices. Software available for these plotting devices is often device dependent. As a result, in order to switch from one plotting device to another, the user has to make several programming changes. This procedure is error prone and time consuming. This paper describes a device independent computer plotting system which is based on several routines accessible from FORTRAN IV. The transition from one plotting device to another is completely transparent to the user of this system. The paper begins with the descriptions of various plotting devices and plotting modes. This is followed by an overview which consists of an example and functional descriptions of all the routines. The system interface and the basis on which the device independence is achieved are discussed in the later portion of the paper. Finally, the data structures used in the offline mode of plotting, the algorithms used in the various driver routines and the mechanism used to account for the plotting resources are presented. The interface for adding a new plotting device has been formalized and defined. The system is open ended and can be expanded in the device independent as well as the device dependent area.Item A digital data recorder and transfer device for the MARCONI 722B Satellite Navigation ReceiverLord, Mark, S.Dr. David Wells of the Department of Surveying Engineering uses a MARCONI 722B Satellite Navigation Receiver in his research. At present, data output from this device is recorded using a paper tape punch. The paper tape produced from the punch is then fed into the IBM 3032 at the U.N.B. Computing Center for calculations and analysis. Needless to say, this methods has proved to be somewhat awkward and cumbersome. The aim of this project is to provide a convenient alternative to the current system, using a micro-computer to collect data directly from the satellite receiver, and then transfer this data to the IBM 3032 through the VSPC online terminal system.Item A DNA barcode examination of the Laminariaceae (Phaeophyceae) in Canada reveals novel biogeographical and evolutionary insights(Taylor and Francis, 2010) McDevit, Daniel, C.; Saunders, Gary, W.DNA barcoding is becoming a widely applied tool for the rapid and accurate identification of eukaryotic species. In this study we used the DNA barcode for large-scale screening of the brown algal family Laminariaceae in Canada. With the examination of 194 COI-5P (5′ end of cytochrome c oxidase 1) sequences (150 newly determined) from representatives of this family, we confirmed the presence of 12 species in Canadian waters (Cymathaere triplicata, Laminaria digitata, L. ephemera, L. setchellii, L. solidungula, L. yezoensis, Macrocystis integrifolia, Nereocystis leutkeana, Postelsia palmaeformis, Saccharina groenlandica, S. latissima and S. sessilis). Saccharina groenlandica, a species with a history of taxonomic confusion, was found in the Pacific, Hudson Bay (subarctic) and Atlantic Canada extending greatly our comprehension of the biogeography of this species. Additionally, COI-5P data from S. latissima, combined with ITS results, provided insights into historical distributional patterns and uncovered a hybridization zone between incipient species in this complex. These discoveries highlight how the growth of a worldwide barcode database for the assignment of individuals to genetic species will uncover new perspectives on biogeography and species diversity on a global scale.Item A DNA barcode examination of the red algal family Dumontiaceae in Canadian waters reveals substantial cryptic species diversity. 1. The foliose Dilsea–Neodilsea complex and Weeksia(Canadian Science Publishing, 2008) Saunders, Gary, W.The field of DNA barcoding is working towards generating a genetic system for the quick and accurate identification of eukaryotic species. For the more systematic minded, however, DNA barcoding offers a new approach towards screening and uniting large numbers of biological specimens in genetic groups as a first step towards assigning them to species and genera in an approach best termed “molecular-assisted alpha taxonomy”. This approach is particularly amenable in organisms with simple morphologies, a propensity for convergence, extensive phenotypic plasticity, and life histories with an alternation of heteromorphic generations. It is hard to imagine a group of organisms better defined by all of these traits than the marine macroalgae. In an effort to assess the utility of the DNA barcode (COI-5′) for testing the current concepts of biodiversity of marine macroalgae in Canada, a study to assess species diversity in the red algal family, Dumontiaceae, was initiated. Through this work I confirm the presence in Canadian waters of Dilsea californica (J. Agardh) Kuntze, Dilsea integra (Kjellman) Rosenvinge, and Neodilsea borealis (I.A. Abbott) Lindstrom of the Dilsea–Neodilsea complex, and Weeksia coccinea (Harvey) Lindstrom for the genus Weeksia. However, our work has uncovered two additional species of the former complex, Dilsea lindstromiae Saunders sp. nov. and Dilsea pygmaea (Setchell) Setchell, and an additional species of the latter, Weeksia reticulata Setchell, effectively doubling representation of these foliose dumontiacean genera in Canadian waters.Item A driver for raster-like plotting devices(1976) Gujar, Uday, G.; Fitzgerald, J., A.Electrostatic plotter type devices, CRT or hardcopy, are basically printers which allow the "paper" movement only in one direction. As a result, the entire display file has to be created before the process of generating the display can begin. This arrangement differs significantly from the X-Y plotters where the "plotting pencil" and/or paper may be moved in any direction. An algorithm for generating a display on the electrostatic plotter type devices is described in this paper. This algorithm is based upon creating and maintaining a vector file consisting of end points of visible vectors, sorting these vectors, and then generating the plot - a strip at a time. Only the points that lie within the strip are calculated. The details of implementation and the data structure used are discussed. There is no restriction on the size of the display that can be generated; in fact, plots of size 100" by 20" have been produced using this algorithm. No a-priori knowledge of the extent of the plot is required. The algorithm has been designed to operate in a device independent computer plotting system and has worked very satisfactorily without imposing any restrictions on the users. Key Words and Phrases: graphics, electrostatic plotters, raster displays, vector generation, data structure, sorting.Item A dynamic data structure for efficient bounded line range search(2010) Le, Thuy, T.; Nickerson, Bradford, G.A dynamic data structure for efficient axis-aligned orthogonal range search on a set of n lines in a bounded plane is presented. The algorithm requires O(log n + k) time in the worst case to find all lines intersecting an axis aligned query rectangle R, for k the number of lines in range. O(n + lambda) space is required for the data structure used by the algorithm, where lambda is the number of intersection points among the lines. Insertion of a new rightmost line l or deletion of a leftmost line l requires O(n) time in the worst case. For a sparse arrangement of lines (i.e., for lambda = O(n)), insertion of a rightmost line l or deletion of a leftmost line l requires O (√n) expected time.Item A dynamic data structure for multi-dimensional range searching(1996) Lamoureau, Michael, G.This thesis addresses the following question: Is it possible to have a k-dimensional data structure which provides for efficient k-d range search and dynamic updates on a set of n points in the worst case while maintaining reasonable storage and preprocessing requirements? Define a data structure to be optimally balanced when the product of its worst case preprocessing, storage, insertion, deletion, and range search cost functions is minimal and dynamically balanced when the product of its insert, delete and range search cost functions is minimal. The optimal balance cost is Q(n2lg4kn) and the dynamic balance cost is O(lg3kn). The optimal worst case range search time is O(lgkn + t) (where we report t points in range) for such structures. Structures optimal for range search in the class of dynamically balanced structures are illustrated and found to be within O(lgk-1n) of optimal. A new k-d structure labeled the k-d Range Deterministic Skip List (DSL) is defined and analyzed along with a new variation of the dynamic range tree labeled the k-d Range AVL tree. Both structures are dynamically balanced and optimal for worst case range search in the model. Experimentally, a mere 20 milliseconds was required to report all 500 datapoints in range for the largest 4-d structure (of 336 MB) built. Both structures perform well. They possess similar update times but we find that the k-d Range DSL is approximately twice as fast as the k-d Range AVL tree for insertions while the k-d Range AVL tree is approximately fifteen times faster for deletions.Item A Fast Incremental Convex Hull Algorithm for Higher Dimensions(1990) Stewart, W. M.; Horton, J. D.An online algorithm is described which finds the facets of the convex hull of a set of points in d-dimensional space. For point sets chosen at random from some distribution, the algorithm is O(nl +F) for fixed d, where n is the number of points, l is the expected number of sides of a polygon defined by the intersection of a 2-flat with the polytope, and F is the expected number of facets.