Showing papers by "University of New Brunswick published in 2011"

Electromyogram pattern recognition for control of powered upper-limb prostheses: state of the art and challenges for clinical use.

Abstract: Using electromyogram (EMG) signals to control upper-limb prostheses is an important clinical option, offering a person with amputation autonomy of control by contracting residual muscles. The dexterity with which one may control a prosthesis has progressed very little, especially when control- ling multiple degrees of freedom. Using pattern recognition to discriminate multiple degrees of freedom has shown great promise in the research literature, but it has yet to transition to a clinically viable option. This article describes the pertinent issues and best practices in EMG pattern recognition, identifies the major challenges in deploying robust control, and advocates research directions that may have an effect in the near future.

Environmental barcoding: a next-generation sequencing approach for biomonitoring applications using river benthos.

Abstract: Timely and accurate biodiversity analysis poses an ongoing challenge for the success of biomonitoring programs. Morphology-based identification of bioindicator taxa is time consuming, and rarely supports species-level resolution especially for immature life stages. Much work has been done in the past decade to develop alternative approaches for biodiversity analysis using DNA sequence-based approaches such as molecular phylogenetics and DNA barcoding. On-going assembly of DNA barcode reference libraries will provide the basis for a DNA-based identification system. The use of recently introduced next-generation sequencing (NGS) approaches in biodiversity science has the potential to further extend the application of DNA information for routine biomonitoring applications to an unprecedented scale. Here we demonstrate the feasibility of using 454 massively parallel pyrosequencing for species-level analysis of freshwater benthic macroinvertebrate taxa commonly used for biomonitoring. We designed our experiments in order to directly compare morphology-based, Sanger sequencing DNA barcoding, and next-generation environmental barcoding approaches. Our results show the ability of 454 pyrosequencing of mini-barcodes to accurately identify all species with more than 1% abundance in the pooled mixture. Although the approach failed to identify 6 rare species in the mixture, the presence of sequences from 9 species that were not represented by individuals in the mixture provides evidence that DNA based analysis may yet provide a valuable approach in finding rare species in bulk environmental samples. We further demonstrate the application of the environmental barcoding approach by comparing benthic macroinvertebrates from an urban region to those obtained from a conservation area. Although considerable effort will be required to robustly optimize NGS tools to identify species from bulk environmental samples, our results indicate the potential of an environmental barcoding approach for biomonitoring programs.

Continuous Locomotion-Mode Identification for Prosthetic Legs Based on Neuromuscular–Mechanical Fusion

Abstract: In this study, we developed an algorithm based on neuromuscular-mechanical fusion to continuously recognize a variety of locomotion modes performed by patients with transfemoral (TF) amputations. Electromyographic (EMG) signals recorded from gluteal and residual thigh muscles and ground reaction forces/moments measured from the prosthetic pylon were used as inputs to a phase-dependent pattern classifier for continuous locomotion-mode identification. The algorithm was evaluated using data collected from five patients with TF amputations. The results showed that neuromuscular-mechanical fusion outperformed methods that used only EMG signals or mechanical information. For continuous performance of one walking mode (i.e., static state), the interface based on neuromuscular-mechanical fusion and a support vector machine (SVM) algorithm produced 99% or higher accuracy in the stance phase and 95% accuracy in the swing phase for locomotion-mode recognition. During mode transitions, the fusion-based SVM method correctly recognized all transitions with a sufficient predication time. These promising results demonstrate the potential of the continuous locomotion-mode classifier based on neuromuscular-mechanical fusion for neural control of prosthetic legs.

Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors.

Abstract: Stable isotopes are now used widely in ecological studies, including diet reconstruction, where quantitative inferences about diet composition are derived from the use of mixing models. Recent Bayesian models (MixSIR, SIAR) allow users to incorporate variability in discrimination factors (Δ13C or Δ15N), or the amount of change in either δ13C or δ15N between prey and consumer, but to date there has been no systematic assessment of the effect of variation in Δ13C or Δ15N on model outputs. We used whole blood from Common Terns (Sterna hirundo) and muscle from their common prey items (fish and euphausiids) to build a series of mixing models in SIAR (stable isotope analysis in R) using various discrimination factors from the published literature for marine birds. The estimated proportion of each diet component was affected significantly by Δ13C or Δ15N. We also use recently published stable-isotope data on the reliance of critically endangered Balearic Shearwaters (Puffinus mauretanicus) on fisheries discards ...

The 2009 edition of the GEISA spectroscopic database

Abstract: The updated 2009 edition of the spectroscopic database GEISA (Gestion et Etude des Informations Spectroscopiques Atmospheriques; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10−6 to 35,877.031 cm−1. The successful performances of the new generation of hyperspectral sounders depend ultimately on the accuracy to which the spectroscopic parameters of the optically active atmospheric gases are known, since they constitute an essential input to the forward radiative transfer models that are used to interpret their observations. Currently, GEISA is involved in activities related to the assessment of the capabilities of IASI (Infrared Atmospheric Sounding Interferometer; http://smsc.cnes.fr/IASI/index.htm) on board the METOP European satellite through the GEISA/IASI database derived from GEISA. Since the Metop-A (http://www.eumetsat.int) launch (19 October 2006), GEISA is the reference spectroscopic database for the validation of the level-1 IASI data. Also, GEISA is involved in planetary research, i.e., modeling of Titan's atmosphere, in the comparison with observations performed by Voyager, or by ground-based telescopes, and by the instruments on board the Cassini–Huygens mission. GEISA, continuously developed and maintained at LMD (Laboratoire de Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS (France) “Ether” Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated management software facilities. More than 350 researchers are registered for on line use of GEISA.

Resolving the Limb Position Effect in Myoelectric Pattern Recognition

Abstract: Reported studies on pattern recognition of electromyograms (EMG) for the control of prosthetic devices traditionally focus on classification accuracy of signals recorded in a laboratory. The difference between the constrained nature in which such data are often collected and the unpredictable nature of prosthetic use is an example of the semantic gap between research findings and a viable clinical implementation. In this paper, we demonstrate that the variations in limb position associated with normal use can have a substantial impact on the robustness of EMG pattern recognition, as illustrated by an in- crease in average classification error from 3.8% to 18%. We propose to solve this problem by: 1) collecting EMG data and training the classifier in multiple limb positions and by 2) measuring the limb position with accelerometers. Applying these two methods to data from ten normally limbed subjects, we reduce the average classification error from 18% to 5.7% and 5.0%, respectively. Our study shows how sensor fusion (using EMG and accelerometers) may be an efficient method to mitigate the effect of limb position and improve classification accuracy.

Jute as raw material for the preparation of microcrystalline cellulose

Abstract: Cellulose was extracted at a yield of 59.8% from jute fibres based on the formic acid/peroxyformic acid process at an atmospheric pressure. The amounts of dissolved lignin and hemicelluloses were determined in the spent liquor. The results showed that the spent liquor contained 10.6% total sugars and 10.9% lignin (based on jute). Microcrystalline cellulose (MCC) was further prepared from the jute cellulose based on the acid hydrolysis technique. A very high yield, 48–52.8% (based on the jute raw material) was obtained. The acid hydrolysate of cellulose contained 2.7% glucose and 0.2% xylose. The MCC samples obtained from two different conditions, one at a low acidity and the other at a high acidity, were characterized by means of Thermo Gravimetric Analysis, Fourier Transform Infrared, X-ray detraction, Scanning Electron Micrograph, and Transmission Electron Micrograph techniques.

Detecting P2P botnets through network behavior analysis and machine learning

Abstract: Botnets have become one of the major threats on the Internet for serving as a vector for carrying attacks against organizations and committing cybercrimes. They are used to generate spam, carry out DDOS attacks and click-fraud, and steal sensitive information. In this paper, we propose a new approach for characterizing and detecting botnets using network traffic behaviors. Our approach focuses on detecting the bots before they launch their attack. We focus in this paper on detecting P2P bots, which represent the newest and most challenging types of botnets currently available. We study the ability of five different commonly used machine learning techniques to meet online botnet detection requirements, namely adaptability, novelty detection, and early detection. The results of our experimental evaluation based on existing datasets show that it is possible to detect effectively botnets during the botnet Command-and- Control (C&C) phase and before they launch their attacks using traffic behaviors only. However, none of the studied techniques can address all the above requirements at once.

Simultaneous and Proportional Force Estimation for Multifunction Myoelectric Prostheses Using Mirrored Bilateral Training

Abstract: This study presents a novel method for associating features of the surface electromyogram (EMG) recorded from one upper limb to the force produced by the contralateral limb. Bilateral-mirrored contractions from ten able-bodied subjects were recorded along with isometric forces in multiple degrees of freedom (DOF) from the right wrist. An artificial neural network was trained to provide force estimation. Combinations of processing parameters were evaluated and an estimation algorithm allowing high accuracy from relatively short signal epochs (100 ms) was proposed. The estimation performance when using surface EMG from the contralateral limb was 0.90 0.02 for the able-bodied subjects. In comparison, the estimation performance for one subject with congenital malformation of the left forearm was 0.72 which, albeit lower than for able-bodied subjects, is still comparable to or better than previously reported results. The proposed method requires only the measured forces from one limb, such as in the case of unilateral amputees and has thus the potential to be used in clinical settings for intuitive, simultaneous control of multiple DOFs in myoelectric prostheses.

VPR 5.0: FPGA CAD and architecture exploration tools with single-driver routing, heterogeneity and process scaling

Abstract: The VPR toolset has been widely used in FPGA architecture and CAD research, but has not evolved over the past decade. This article describes and illustrates the use of a new version of the toolset that includes four new features: first, it supports a broad range of single-driver routing architectures, which have superior architectural and electrical properties over the prior multidriver approach (and which is now employed in the majority of FPGAs sold). Second, it can now model, for placement and routing a heterogeneous selection of hard logic blocks. This is a key (but not final) step toward the incluion of blocks such as memory and multipliers. Third, we provide optimized electrical models for a wide range of architectures in different process technologies, including a range of area-delay trade-offs for each single architecture. Finally, to maintain robustness and support future development the release includes a set of regression tests for the software.To illustrate the use of the new features, we explore several architectural issues: the FPGA area efficiency versus logic block granularity, the effect of single-driver routing, and a simple use of the heterogeneity to explore the impact of hard multipliers on wiring track count.

A Distributed Key Management Framework with Cooperative Message Authentication in VANETs

Abstract: In this paper, we propose a distributed key management framework based on group signature to provision privacy in vehicular ad hoc networks (VANETs). Distributed key management is expected to facilitate the revocation of malicious vehicles, maintenance of the system, and heterogeneous security policies, compared with the centralized key management assumed by the existing group signature schemes. In our framework, each road side unit (RSU) acts as the key distributor for the group, where a new issue incurred is that the semi-trust RSUs may be compromised. Thus, we develop security protocols for the scheme which are able to detect compromised RSUs and their colluding malicious vehicles. Moreover, we address the issue of large computation overhead due to the group signature implementation. A practical cooperative message authentication protocol is thus proposed to alleviate the verification burden, where each vehicle just needs to verify a small amount of messages. Details of possible attacks and the corresponding solutions are discussed. We further develop a medium access control (MAC) layer analytical model and carry out NS2 simulations to examine the key distribution delay and missed detection ratio of malicious messages, with the proposed key management framework being implemented over 802.11 based VANETs.

Online sexual activity experience of heterosexual students: gender similarities and differences.

Abstract: This study compared male and female university students’ experiences with online sexual activity (OSA) and tested a model explaining gender differences in OSA. OSAs were categorized as non-arousal (e.g., seeking sexuality information), solitary-arousal (e.g., viewing sexually explicit materials), or partnered-arousal (e.g., sharing sexual fantasies). Participants (N = 217) completed measures of OSA experience, sexual attitudes, and sexual experience. Significantly more men than women reported engaging in solitary-arousal and partnered-arousal OSA and doing so more often. However, the men and women who reported having engaged in partnered-arousal activities reported equal frequencies of experience. There were no significant gender differences for engaging in non-arousal OSA experience. These results support the importance of grouping OSAs in terms of the proposed non-arousal, solitary-arousal, and partnered-arousal categories. Attitude toward OSA but not general attitudes toward or experiences with sexuality partially mediated the relationship between gender and frequency of engaging in arousal-oriented OSA (solitary and partnered OSA). This suggests that attitude toward OSA specifically and not gender socialization more generally account for gender differences in OSA experience.

Cumulative Abuse: Do Things Add Up? An Evaluation of the Conceptualization, Operationalization, and Methodological Approaches in the Study of the Phenomenon of Cumulative Abuse:

Abstract: For women, any one type of abuse rarely occurs in isolation of other types, and a single abusive experience is often the exception rather than the norm. The importance of this concept of the cumulative nature of abuse and its negative impact on health has been well recognized within the empirical literature, however there has been little consensus on what to call this phenomenon or how to study it. For the most part researchers have operated on the premise that it is the sheer number of different types of cumulating abuse experiences that is primarily responsible for worse health outcomes among women. And although this simplistic 'more is worse' approach to conceptualizing and operationalizing cumulative abuse has proven to be a powerful predictor of poorer health, it contradicts growing empirical evidence that suggests not all victimizations are created equal and that some victimizations may have a more deleterious effect on health than others. Embedded in abuse histories are individual and abuse characteristics as well as other life adversities that need to be considered in order to fully understand the spectrum and magnitude of cumulative abuse and its impact on women's health. Furthermore, given the long-term and persistent effects of abuse on health it becomes imperative to not only evaluate recent abusive experiences, but rather all abuse experiences occurring across the lifespan. This review highlights and evaluates the conceptual, operational, and methodological challenges posed by our current methods of studying and understanding the phenomenon of cumulative abuse and suggests that this phenomenon and its relationship to health is much more complex than research is currently portraying. This paper calls for the urgent need for interdisciplinary collaboration in order to more effectively and innovatively study the phenomenon of cumulative abuse. Language: en

The importance of wasta in the career success of Middle Eastern managers

Abstract: Purpose – Frequently used in fostering the career progression of individuals this paper aims to explore the concept of wasta and its significance in the career advancement of individuals in the Middle Eastern region. The paper also seeks to compare wasta with networking and mentoring.Design/methodology/approach – The argument is based on relevant literature, the authors' own knowledge through conducting research in the Arab world, informal interviews and survey data conducted across the Middle Eastern Region.Findings – The research clearly shows that on balance wasta remains traditional in its influence in the career advancement of individuals and business life and social life and is unlikely to diminish in the near future, despite the perception that it is an unfair practice. Wasta also displays similarities and differences with networking and mentoring.Research implications/limitations – Fundamental knowledge on wasta is limited precluding reliable conclusions on how wasta compares with networking and m...

Behaviour during elevated water temperatures: can physiology explain movement of juvenile Atlantic salmon to cool water?

Abstract: Summary 1. Temperature governs most physiological processes in animals. Ectotherms behaviourally thermoregulate by selecting habitats with temperatures regulating their body temperature for optimal physiological functioning. However, ectotherms can experience temperature extremes forcing the organisms to seek temperature refuge. 2. Fish actively avoid potentially lethal temperatures by moving to cool-water sites created by inflowing tributaries and groundwater seeps. Juvenile Atlantic salmon (Salmo salar) of different age classes exhibit different behavioural responses to elevated temperatures (>23 °C). Yearling (1+) and 2-year-old (2+) Atlantic salmon often cease feeding, abandon territorial behaviour and swim continuously in aggregations in cool-water sites; whereas young-of-the-year (0+) fish continue defending territories and foraging. 3. This study determined whether the behavioural shift in older individuals (2+) occurred when basal metabolic rate, driven by increasing water temperature, reached the maximum metabolic rate such that anaerobic pathways were recruited to provide energy to support vital processes. Behaviour (feeding and stress responses), oxygen consumption, muscle lactate and glycogen, and circulating blood lactate and glucose concentrations were measured in wild 0+ and 2+ Atlantic salmon acclimated to water temperatures between 16 and 28 °C. 4. Results indicate that oxygen consumption of the 2+ fish increased with temperature and reached a plateau at 24 °C, a temperature that corresponded to cessation of feeding and a significant increase in muscle and blood lactate levels. By contrast, oxygen consumption in 0+ fish did not reach a plateau, feeding continued and muscle lactate did not increase, even at the highest temperatures tested (28 °C). 5. To conclude, the experiment demonstrated that the 0+ and 2+ fish had different physiological responses to the elevated water temperatures. The results suggest that wild 2+ Atlantic salmon employ behavioural responses (e.g. movement to cool-water sites) at elevated temperatures in an effort to mitigate physiological imbalances associated with an inability to support basal metabolism through aerobic metabolic processes.

Selective Classification for Improved Robustness of Myoelectric Control Under Nonideal Conditions

Abstract: Recent literature in pattern recognition-based myoelectric control has highlighted a disparity between classification accuracy and the usability of upper limb prostheses. This paper suggests that the conventionally defined classification accuracy may be idealistic and may not reflect true clinical performance. Herein, a novel myoelectric control system based on a selective multiclass one-versus-one classification scheme, capable of rejecting unknown data patterns, is introduced. This scheme is shown to outperform nine other popular classifiers when compared using conventional classification accuracy as well as a form of leave-one-out analysis that may be more representative of real prosthetic use. Additionally, the classification scheme allows for real-time, independent adjustment of individual class-pair boundaries making it flexible and intuitive for clinical use.

Incorporating traits in aquatic biomonitoring to enhance causal diagnosis and prediction

Abstract: The linkage of trait responses to stressor gradients has potential to expand biomonitoring approaches beyond traditional taxonomically based assessments that identify ecological effect to provide a causal diagnosis. Traits-based information may have several advantages over taxonomically based methods. These include providing mechanistic linkages of biotic responses to environmental conditions, consistent descriptors or metrics across broad spatial scales, more seasonal stability compared with taxonomic measures, and seamless integration of traits-based analysis into assessment programs. A traits-based biomonitoring approach does not require a new biomonitoring framework, because contemporary biomonitoring programs gather the basic site-by-species composition matrices required to link community data to the traits database. Impediments to the adoption of traits-based biomonitoring relate to the availability, consistency, and applicability of existing trait data. For example, traits generalizations among taxa across biogeographical regions are rare, and no consensus exists relative to the required taxonomic resolution and methodology for traits assessment. Similarly, we must determine if traits form suites that are related to particular stressor effects, and whether significant variation of traits occurs among allopatric populations. Finally, to realize the potential of traits-based approaches in biomonitoring, a concerted effort to standardize terminology is required, along with the establishment of protocols to ease the sharing and merging of broad, geographical trait information.

Comparative Analyses of the YLS/CMI, SAVRY, and PCL:YV in Adolescent Offenders: A 10-year Follow-Up Into Adulthood

Abstract: A growing body of research has been dedicated to developing adolescent risk assessment instruments, but much of this research has been limited to short-term tests of predictive validity. The current study examined the predictive and incremental validity of the Youth Level of Service/ Case Management Inventory (YLS/CMI), Structured Assessment of Violence Risk in Youth (SAVRY), and Psychopathy Checklist: Youth Version (PCL:YV) in adolescent offenders over a mean 10-year follow-up period. Each instrument predicted general recidivism with moderate- (YLS/CMI area under the curve [AUC] = .66) -to-large effect sizes (SAVRY AUC = .74; PCL:YV AUC = .79). However, there was variation in predictive validity across types of recidivism, and all three instruments were better at predicting recidivism in males than females. SAVRY total also demonstrated incremental validity over its structured professional judgment of risk. Clinical implications and future directions for youth risk assessment are discussed.

Time limits and gender differences on paper-and-pencil tests of mental rotation: a meta-analysis.

Abstract: The purpose of this study was to summarize research relevant to the influence of time limits on gender differences in paper-and-pencil tasks of mental rotation by means of a meta-analysis. Thirty-six effect sizes from published and unpublished studies examining the influence of time constraints were retrieved. Results showed that gender differences in mental rotation are significantly larger when the task is administered with time constraints compared to when such constraints are absent. In addition, the magnitude of gender differences was linearly related to the amount of time available for test completion. These findings were not related to the age or the year of birth of participants in the retrieved studies. The results are discussed with regard to their implications for explanations of gender differences in mental rotation and cognitive abilities in general.

Beyond the birds and the bees and was it good for you?: Thirty years of research on sexual communication.

Abstract: Sexual experience and expression is of fundamental importance to most people. However, most people do not communicate effectively about sexuality even when it is important to do so. For example, many parents see it as their responsibility to talk to their children about sexuality and yet do not engage in in-depth discussions with their children about sexual topics. Most romantic partners have difficulty telling each other what pleases and displeases them sexually. Many health care professionals do not meet their patients' needs for information about the sexual changes they experience as a result of their disease or treatment. Many psychologists also are not doing a good job of addressing sexuality in the classroom, in practicum and internship settings, and/or with clients. These instances of poor sexual communication are unfortunate as effective sexual communication can have a range of positive outcomes such as more satisfying relationships and positive sexual health and well-being over the life span. This paper reviews sexual communication in all of these contexts, focusing on findings from my program of research spanning more than 30 years. Keywords: sexual communication, sexual education, couples, adolescents It is a truism to state that sexual experience and expression is of fundamental importance to most people; indeed, this statement is not controversial and needs no citations. There is no place in which this is more evident than in the media. Certainly, sexual images and tips about enhancing our sexual relationships, sexual experiences, and ability to please our partner are ubiquitous in the media. There is a great deal that has been and could be said about the content and impact of these media messages, particularly about their negative effects, but that is a topic for another time and place and is not the focus of the present paper. Rather, this paper focuses on interpersonal sexual communication - between parents and their children, between partners, between health care professionals and their patients, between professors and psychology graduate students, and between psychologists and their clients. I have drawn on select data (i.e., data from larger studies) from several strands of my research program spanning more than 30 years to support my contention that there is a great deal of room for improvement in how we communicate about sexuality in every one these contexts. Because each section of this paper could be a review paper in its own right, I have not, for the most part, reviewed the results of studies by other researchers on these topics. There are two major limitations to my research that are important to identify from the outset. One is that most, if not all, of the research I cite is with heterosexual individuals. This is because, typically, there have not been enough sexual minority participants for me to be able to analyse their data. The other limitation is that, in keeping with the population of New Brunswick where I conduct my research, the participants in my studies are primarily white and of European descent. Still, sexual communication among most ethnocultural minority groups living in Canada is even more limited than among the majority culture (Cappon et al., 1996; Manson Singer et al., 1996) suggesting that, if anything, the results would be stronger among these groups. Parent-Child Sexual Communication or the Birds and the Bees Most parents believe that they have a role to play in their children's sexual health education as a way to communicate family values, prevent negative sexual health outcomes, and prepare their children for adulthood (Croft & Asmussen, 1992; McKay, Pietrusiak, & Holowaty, 1998; Weaver, Byers, Sears, Cohen, & Randall, 2002). Although parents may not readily identify this as a goal of their sexual communication with their children, I believe that communicating positive attitudes toward both sexuality and talking about sexual topics is another important outcome of parent- child sexual communication. …

On the paradigm of altruistic suicide in the unicellular world

Abstract: Altruistic suicide is best known in the context of programmed cell death (PCD) in multicellular individuals, which is understood as an adaptive process that contributes to the development and functionality of the organism. After the realization that PCD-like processes can also be induced in single-celled lineages, the paradigm of altruistic cell death has been extended to include these active cell death processes in unicellular organisms. Here, we critically evaluate the current conceptual framework and the experimental data used to support the notion of altruistic suicide in unicellular lineages, and propose new perspectives. We argue that importing the paradigm of altruistic cell death from multicellular organisms to explain active death in unicellular lineages has the potential to limit the types of questions we ask, thus biasing our understanding of the nature, origin, and maintenance of this trait. We also emphasize the need to distinguish between the benefits and the adaptive role of a trait. Lastly, we provide an alternative framework that allows for the possibility that active death in single-celled organisms is a maladaptive trait maintained as a byproduct of selection on pro-survival functions, but that could-under conditions in which kin/group selection can act-be co-opted into an altruistic trait.

A Generalized Technique of Modeling, Analysis, and Control of a Matrix Converter Using SVD

Abstract: In this paper, a new simple and complete technique of modeling and analysis of a matrix converter is presented based on the singular value decomposition (SVD) of modulation matrix. The proposed modeling method yields a new limitation between the matrix converter gain and its input power factor, which is more relaxed as compared to the limits reported so far in the literature. The SVD of the modulation matrix leads to a unified modulation technique which achieves the full capability of a matrix converter. It is shown that this approach is general and all other modulation methods established for a matrix converter are specific cases of this technique. The proposed modulation method can be used to obtain the maximum reactive power in the input of a matrix converter in applications such as wind turbine and microturbine generators, where the input reactive power control is necessary.