Dan Ionescu

• Ph.D.
• Professor (Full) at University of Ottawa

Convolutional neural networks (CNN), more recently, have greatly increased the performance of face recognition due to its high capability in learning discriminative features. Many of the initial face recognition algorithms reported high performance in the small size Labeled Faces in the Wild (LFW) dataset but fail to deliver same results on larger...

Abstract—Web-based collaborative platforms and co-editing tools are now vital components of modern organizations seeking to enhance team productivity and efficiency. Although the underlying optimistic consistency maintenance techniques for keeping content synchronized across multiple sites have been studied by researchers since the eighties, no inv...

A variety of contemporary technologies are being framed within the Internet of Things (IoT) architecture, including publish/subscribe (pub/sub) systems. In IoT, things, such as objects, machines, vehicles, and wireless sensors, have to communicate with other things or humans and exchange information based on Internet connectivity. With the integrat...

Accurate positioning of objects within an indoor environment is essential for applications such as virtual reality, robotics and multirotor drones. Previous methods of obtaining six-degrees-of-freedom for a tracked object have been susceptible to latency and accumulated error, computationally intensive, inaccurate, costly, or required exotic compon...

Modern web frameworks and backend-as-a-service providers make it possible for real-time updates to a NoSQL data model to be reflected in the user interfaces of multiple subscribing end-user applications. However, it remains difficult for users to dynamically discover and instantly make use of the data provided by the plethora of REST APIs in existe...

The increased availability of consumer-grade virtual reality (VR) head-mounted displays (HMD) has created significant demand for affordable and reliable 3D input devices that can be used to control 3D user interfaces. Accurate positioning of a user's body within the virtual environment is essential in order to provide users with convincing and inte...

Cloud computing has become an integral technology both for the day-to-day running of corporations, as well as for people life as more services are offered which use a back-end cloud. For the cloud providers, the ability to maintain the systems’ Service Level Agreements and prevent service outages is paramount since long periods of failures can open...

Slides for SACI 2015 presentation: A Graph Digital Signal Processing Method for Semantic Analysis

This paper focuses on the problem of devising a computationally tractable procedure for representing the natural language understanding (NLU). It approaches this goal, by using distributional models of meaning through a method from graph-based digital signal processing (DSP) which has recently grabbed the attention of researchers from the field of...

Synchronous, and real-time web-based collaboration on text and multimedia content is a hot research subject. Currently collaborative multimedia applications are loosely defined. It is current practice to consider any application that allows users to connect to each other in order to exchange information in writing or through video streams, in real-...

For more than a decade, the eHealth initiative has been a government concern of many countries. In an Electronic Health Record (EHR) System, there is a need for sharing the data with a group of specialists simultaneously. Collaborative platforms alone are just a part of a solution, while a collaborative platform with parallel editing capabilities a...

Data production has recently witnessed explosive growth, reaching an amount larger than 4 zetabytes in 2013. This includes data sources such as sensors used to gather climate information, posts to social media sites containing digital pictures and videos, purchase transaction records, and cell phone GPS signals, to name a few. Not yet having more t...

There is a large amount of sustained research activity in the area of Human-Computer Interaction (HCI). Gesture control is one of hottest in this field. Although gesture control research began with terminals attached to computers in combination with a pointing device, the large scale implementation and utilization of gesture control continues to be...

Gesture-based human-computer interaction is presently an important area of research that aims to make reliable touch-free user interfaces a reality. More recent gesture detection technologies use cameras that rely on near-infrared (NIR) illumination to obtain 3D depth information for objects within the camera's field-of-view. These cameras use eith...

As digital components are increasingly present in the control of automotive engines, direction systems and other in-car devices, Human-Vehicle Interaction (HVI) becomes more and more complex, requiring new user interfaces. Gesture control is proposed in the literature as a techniques which deserves to be explored as it can tremendously simplify num...

The IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) allows a node to operate in storing or non-storing mode. However, as the network size increases, non-storing RPL will introduce lots of communication overhead, while storing RPL will consume lots of memory. In this paper, we improve the storing mode in RPL by reducing the memory consu...

In the past few years, cloud computing has become an integral technology both for the day to day running of corporations, as well as in everyday life as more services are offered which use a backend cloud. At the same time online collaboration tools are becoming more important as both businesses and individuals need to share information and collabo...

Gesture Control dominates presently the research on new human computer interfaces. The domain covers both the sensors to capture gestures and also the driver software which interprets the gesture mapping it onto a robust command. More recently, there is a trend to use depth-mapping camera as the 2D cameras fall short in assuring the conditions of r...

XCP is one of the most commonly used protocols in modern congestion control implementations. XCP can provide the available transmission rate to applications. It is well known fact that one of the issues of XCP is that the time-delay of its traditional implementation (TR-XCP) is twice the time-delay of its flow model. This leads to unstable behavior...

In recent years cloud computing has taken off and has become an underlying technology in many online applications and websites, whether using a private or public cloud. At the same time with the increase in globalization, online collaborative tools have become very important in order to allow different businesses to communicate with each other, or...

Gesture Control is a subject which has been investigated almost from the beginning of using terminals to interact with the computer central unit. The advent of Kinect, has sparked a series of efforts to apply gesture control not only in gaming, but rather in controlling TVs or set-top boxes, PCs, laptops, and others. Gestures have been captured by...

Since the introduction Gesture Control technology in the electronic gaming technology a series of attempts have been made to deploy it also on other domains such as robotics, teaching, medical, automotive and many others. Human gesture used for Man-Machine Interaction became attractive as it offers a simpler way of controlling sophisticated devices...

Presently the Internet accommodates simultaneous audio, video, and data traffic. This requires the Internet to guarantee the packet loss thus to control network congestion. A series of protocols have been introduced to supplement the insufficient TCP mechanism for controlling the congestion. As such the Core-Stateless Fair Queuing (CSFQ), Token-Bas...

A system for multimedia communications implemented With reconfigurable technology is disclosed. The system includes: a SIP engine implemented in hardware that executes functions defined by Session Initiation Protocol (SIP); a XML engine implemented in hardware that executes functions defined by Extensible Markup Language (XML); and an interface tha...

A system for multimedia communications implemented With reconfigurable technology is disclosed. The system includes: a SIP engine implemented in hardware that executes functions defined by Session Initiation Protocol (SIP); a XML engine implemented in hardware that executes functions defined by Extensible Markup Language (XML); and an interface tha...

A gesture-based human computer interface can make computers and devices easier to use, such as by allowing people to share photos by moving their hands through the air. Existing solutions have relied on exotic hardware, often involving elaborate setups limited to the research lab. Gesture recognition algorithms used so far are not practical or resp...

A Traffic Engineering (TE) algorithm for multicast traffic distribution over Differentiated Services (Diff-Serv) aware with Multiprotocol Label Switching Traffic Engineering (MPLS-TE) networks is proposed. The algorithm can be used to forward multicast traffic offered by internet service providers (ISP) and solicited by clients based on their subsc...

Cloud Computing is defined as a pool of virtualized computer resources deployed and scaled-out quickly through the rapid provisioning of virtual or physical machines. Virtual machine services offered by cloud utility providers led to the creation of the ecosystem of cloud services as they enable customers to use computing resources based on the dyn...

With the advent of social networking and the appearance of Web 2.0, collaborative applications which allow users to share data online, often in real-time, have gained increasing prominence. Whether for sharing images, sharing videos, or even sharing live gaming sessions, such applications must deal with session sizes from tens to tens of thousands...

This paper presents an architecture to define and disseminate heterogeneous data between multiple participants in real-time using the IP Multimedia Subsystem (IMS) with Field Programmable Gate Array (FPGA) development platforms. IMS is a communications framework permitting the exchange of data between communications devices across divergent network...

Presently, the Internet accommodates simultaneous audio, video, and data traffic. This requires the Internet to guarantee the packet loss which at its turn depends very much on congestion control. A series of protocols have been introduced to supplement the insufficient TCP mechanism controlling the network congestion. CSFQ was designed as an open-...

The amount of multimedia content on the Internet has been growing at a remarkable rate, and users are increasingly looking to share online media with colleagues and friends on social networks. Several commercial and academic solutions have attempted to make it easier to share this large variety of online content with others, but they are generally...

Although investigated from early days of research in the domain of human-computer interfaces, gesture-based control of computer application entered in the everyday life of computer users with the advent of 3D infrared cameras. The usage of real-time depth-mapping cameras and of robust image processing applied the flow of depth map streams triggered...

It is known fact that modern IP networks are adopting eXplicit Control Protocol (XCP) as the de-facto standard. In the implementation of XCP, the XCP sender outputs packets in bursts such that all the packets inside the congestion window are outputted without any interval between them. The burst not only increases the queuing delay, but also makes...

The underlying technologies of web information and distributed systems often require efficient XML parsing. Even though new software-based XML parsing techniques improve XML processing, the verbose nature of XML does not help to achieve the substantial improvements that are desired. In some systems, such as mobile devices, the restricted memory res...

The control of virtual video game environments through body motion is recently of great interest to academic and industry research groups since it enables many new inter- active experiences. With the recent growth in the availability of affordable 3D camera technology, researchers have increasingly investigated the control of games through body and...

Recently a great deal of research has been under- taken in the area of automating the enterprise IT Infrastructure. For enterprises with a large number of computers the IT Infrastructure operation represents a considerable amount of the enterprise budget. Autonomic Computing Systems are systems which were created for minimizing this budget componen...

In this paper various design principles and autonomic computing algorithms for on the-cloud services are discussed. The emphasis will be set on issues such as real-time architectures for autonomic computing with reference to virtualization and on-the-cloud computing, the self-organizing algorithms for the local autonomic computing cell present in e...

The amount of multimedia content on the internet has been growing at a remarkable rate, and users are increasingly looking to share online media with colleagues and friends on social networks. Several commercial and academic solutions have attempted to make it easier to share this large variety of online content with others, but they are generally...

Motion-based control of video games has gained significant attention from both academic and industrial research groups for the unique interactive experiences it offers. Of particular research interest has been the control of games through gesture-based interfaces enabled by 3D cameras that have recently been made affordable. However, existing resea...

Services such as multimedia, VoIP, video-conferencing, social networking and others impose new requirements on providers and constraints on network designers. Fair Queueing algorithms like CSFQ or Stochastic Fair BLUE have been used to improve the quality of the packet transmission. Such mechanisms usually supervise the bandwidth consumption per-fl...

This paper presents a self-tuning adaptive control structure designed through the minimization of a criteria function. It is described the computation methodology of the control law, being particularized for the case of a dual winding induction generator's excitation control. The parameter's estimator, integrated into the control system, is based o...

The control of computers and electronics through hand gestures has gained significant industry and academic attention lately for the usability benefits and convenience that it offers users. Of particular research interest has been the control of living room environments containing televisions and set-top boxes. However, existing research has failed...

Nowadays Service Providers (ISP) are more interested in deploying new traffic engineering (TE) methods offered by Multiprotocol Label Switching Traffic Engineering (MPLS-TE) path-oriented forwarding technology. The attractiveness of this technology is encouraged by the possibility to deploy better forwarding performance, constrained based routing r...

Autonomic Computing is a research area whose aim is to embed “intelligent algorithms” in the IT infrastructure management software such that it can adapt to changes in regards to the configuration, provisioning, external attacks, and resource utilization variations at run time. It is therefore, almost natural to consider this IT infrastructure cont...

form only given. Human-computer interfaces (HCI) have evolved from mouse-keyboard based interaction using text and mouse events to multi-touch screens and other exotic approaches such as using special gloves or other devices to translate human actions into application controls. One of the trends which are “en vogue” in our days is the control of co...

Mobile sensors networks are used in several domains to perform various tasks related to monitoring, recording, and affecting the conditions of an environment. Interacting with mobile sensor networks deployed in public networks requires an application capable of securely exchanging data in the network, generating mobile sensor network requests and p...

In this paper, we present a novel hardware-based XML/XPath broker architecture for content-based Publish/ Subscribe systems. Our broker architecture includes processors to parse XML published content and XPath subscriptions, a matching engine to match subscriptions against publications, and components to forward either subscriptions or notification...

The usage of a novel real-time depth-mapping principle, and of a 3D camera which embodies the new depth-mapping principle to control a number of computer applications ranging from games to collaborative multimedia environments, is described in this paper. The 3D camera has a variable depth resolution obtained from images of 1024×1024 pixels. By usi...

Current approaches to game strategy make reference to the use of AI techniques in order the better predict the players' behavior. More recently the 3D sensor based gaming has spread rapidly in the PC and console gaming and gamers' communities. The sensor based gaming has changed dramatically the gaming design forcing it to move away from triggered...

When provisioning quantitative quality of service (QoS) for virtual private network (VPN) services over packet switched networks, parameters such as packet loss, delay, and delay jitter, besides the required bandwidth, have to be guaranteed. While the bandwidth is relatively easier to guarantee, maintaining a value of the packet loss parameter belo...

There is a growing need for the automation of the IT infrastructure of enterprises. Autonomic computing provided a theoretical support for the foundation of mechanisms for self-optimization of computational resources at all the levels of the IT infrastructure of the enterprise. As the Autonomic Computing paradigm requires collecting information in...

The distribution of real-time GIS (Geographic Information System) data among users is now more important than ever as it becomes increasingly affordable and important for scientific and government agencies to monitor environmental phenomena in real-time. A growing number of sensor networks are being deployed all over the world, but there is a lack...

Sensor networks that distribute real-time GIS (Geographic Information System) data are being deployed across the world more than ever as it becomes increasingly affordable and important for scientific and government agencies to monitor environmental phenomena. As the amount of data sources increases, the lack of services for connecting users to the...

A novel real-time depth-mapping principle and camera where pulsed laser light is combined with a gain-modulated camera and a phase-locked loop control of laser intensity is described in this paper. The depth resolution is variable depending on the resolution of the camera and of the gating possibilities of the sensor. A sensor of 1 Mpixel is used p...

The architecture of IP Multimedia Subsystem (IMS) enables converged voice, video, and data services and contains mechanisms related to session and connection control. Numerous protocols are used to perform IMS operations however the Session Initiation Protocol (SIP) plays a central role in the functionality of IMS. With increased demand for multime...

Autonomic Computing Systems are systems which are capable of adapting themselves to changes in their working environment in order to maintain required service level agreements, protect the execution of the system from external attacks or prevent and recover from failures. Within the field of autonomic computing, autonomic systems are developed as c...

Software as a service (SaaS) can be delivered by composing software applications using web services hosted in one or more administrative domains. In this context, web service composition has a considerable impact on the delivered service affecting its quality (QoS). There is therefore a need to keep the service QoS parameters under control when the...

A search results ranking method that uses semantic features and a cluster coherence measure is introduced in this paper. The quality of the returned search results is improved by grouping semantically related texts into clusters displayed in descending cluster size order. First the term-document matrix is constructed where the documents correspond...

XML and its schema language mainly built to encode documents electronically are widely used for a variety of purposes in modern programming. XML Schema is developed in the context of a domain specific terminology. Schema mapping describes the semantic correspondences between the components of two XML Schema documents. An XML Schema document describ...

This paper presents a reconfigurable architecture for the session initiation protocol (SIP). SIP is a protocol used primarily to establish point-to-point sessions between users for multimedia communication. Furthermore it increases the performance of Internet applications and overall efficiency. However, most existing SIP solutions are entirely sof...

The advent of IP/MPLS based networks allows providers to implement integrated services packet network (ISPN) concepts for IPTV applications. IPTV systems require a high level of quality of service (QoS) in order to win customers which are subscribed with cable companies. Packet loss probability is one of the primary QoS parameters whose value affec...

With the widespread popularity of XML, many communication and multimedia standards are being developed based completely or partially on XML. The session initiation protocol is a signaling mechanism - frequently used for multimedia applications - that comprises XML-based ldquopresencerdquo information particularly useful in instance messaging.The pr...

The need for efficient XML parsing becomes a key requirement in the underlying technologies of Web information and distributed systems. Even though new software-based XML parsing techniques have been studied to improve XML processing, the verboseness nature of XML does not help much to achieve substantial improvement. Hardware-based solutions can b...

Discrete event systems have been researched for quite a while in the domain literature. A series of modelling and analysis techniques have been used. Petri net models give an opportunity of their studies and theories have been born to provide tools for their design. Automatic transport systems with accumulation areas are a particular type of system...

With the increase in popularity experienced by Web 2.0 applications both for personal and for business use, there is a need to study how Web 2.0 changes traffic patterns and what is the impact of Web 2.0 applications on the underlying network and server infrastructure. This paper proposes as measurement-oriented traffic characterization method that...

In this paper, a new packet loss probability (PLP) estimation method is developed based on the Kalman estimation procedure. The Kalman filter is used for the optimal and recursive estimation of the network traffic mean and standard deviation. The estimation is obtained from past measurements to calculate the one-step prediction and is then applied...

Abstract - A new approach is introduced for large scale automatic information extraction: Named Entity Recognition and Relation Extraction from a large corpus of text documents. The approach allows also for semantic search operations to be issued. The corpus is first processed by a sentence tokenizer, then by a morphologic and syntactic parser gene...

Traditionally, IP networks offer a single, best effort class-of-service. In order to support multiple services, the converged IP network must provide Quality of Service (QoS). One of the most difficult QoS areas is named as congestion avoidance. Today¿s router implementations depend solely on RED or lately WRED (Weighted Random Early Detection) fo...

P2P applications have been seen as one of the most elegant and simple Web applications which stirred a lot of controversy as they were a vehicle for many Web activities which were and are not legal. The P2P technology has been applied to many domains, from applications spanning the space of music downloading to communication system management etc....

Autonomic systems received lately a great deal of interest from the research and industrial communities due to their ability to configure, optimize, heal and protect themselves with little to no human intervention. Such systems must be able to analyze themselves and their environment in order to determine how best they can achieve the high-level go...

Environmental monitoring requires that raw data acquired from sensors and/or data repositories be transformed, by scientific analysis, into assessments of current ecosystem conditions and in evolution trends in time and space. The huge data amount produced by different sources, the complexity of the environmental models adopted and the necessary di...

The rapid development of sensor technology led to large deployments of collections of sensing nodes working together to collect information for light, temperature, atmospheric pressure, air pollutions parameters, images, and other relevant data according to specific Environmental applications. The ability of the sensor networks to collect informati...

Differentiated services (DiffServ) define the per-hop-behavior (PHB) to enable scalable network designs with QoS support for multiple classes. MPLS traffic engineering (MPLS TE) enables resource reservation, fault-tolerance, and optimization of network resources. From the implementation point of view, the QoS is provided on the forwarding plane whi...

Software as a service creates the possibility of composing software applications from web services spread across different application domains. To guarantee certain quality of services of the composite service, one can think of two paths ahead: quality of service negotiation and guarantee prior to service deployment and bindings; or a more speculat...

Discrete event systems have been researched for quite a while in the domain literature. A series of modelling and analysis techniques have been used. Sequential automata models are at the basis of their studies and theories have been born to provide tools for their design. Automatic transport systems with accumulation areas are a particular type of...

The increasing heterogeneity and complexity of the Information Technology infrastructure encompassing hardware and software applications, services and networks, led to complex, unmanageable and insecure systems. Correspondingly, new approaches in regards to the IT infrastructure automation and operation have been investigated. Autonomic computing h...

Virtualization for the x86 platform has imposed itself recently as a new technology that can improve the usage of machines in data centers and decrease the cost and energy of running a high number of servers. Similar to virtualization, autonomic computing and more specifically self-optimization, aims to improve server farm usage through provisionin...

It is a trend that the integrated voice, video and data will be transported in the converged IP/MPLS core network. The combined use of the differentiated services (DiffServ) and multiprotocol label switching (MPLS) technologies is envisioned to provide guaranteed quality of service (QoS). However, such a scheme only dictates per hop behavior (PHB)...

Providers of data network services are in search of new solutions for service offerings over integrated service packet networks which can accommodate voice and video traffic in addition to data traffic. The goal is to provide users with cutting-edge services such as IP telephony, video conferencing, video on demand, telemedicine, etc. As the tradit...

A new method for capturing and reconstructing 3D representations of real objects in a virtual reality system is introduced. Virtual reality applications allow users to navigate and interact with the 3D objects through the environment. This interaction requires that the 3D representation of real objects be highly accurate in modeling the reality. Th...

Autonomic computing aims to embed automation in IT management software such that it can adapt to changes in the configuration, provisioning, protection, and resource utilization variations of the IT infrastructure at run time. It is, therefore, almost natural to consider this control software framework as being designed with control principles in m...

The support for quality of service has become an absolute must in present data communication networks, as they must now adapt in order to transport time-critical applications, such as voice and video. Great efforts have been made to make the best-effort IP infrastructure suitable for these next-generation applications. QoS frameworks such as IntSer...

Web services are commonly used by organizations for B2B integration and enterprise application integration. UDDI registries are widely used as mechanisms for businesses to list and discover available services. Businesses may want to limit the information of their services to certain users and businesses. However, UDDI provides no mechanisms to limi...