Showing papers by "Shyamanta M. Hazarika published in 2013"

A biomimetic similarity index for prosthetic hands

Abstract: Extreme upper limb prosthesis is a well researched problem. There are a number of research prototypes and a few sophisticated commercially launched variants. For a wider acceptance among amputees, prosthetic hands need to be anthropomorphic i.e. replicate the human hand in form and function. However, it is often difficult to compare and rank prosthetic hands on the extent of their being anthropomorphic. The focus of this paper is to evolve a framework for quantification of anthropomorphism for prosthetic hands. Using Formal Concept analysis, a formal context of anthropomorphism is constructed. Within such a context, an index expressing similarity between the prosthetic and the human hand is derived. Following on the lines of the functional similarity metric for design-by-analogy put forward by McAdams and Wood, a formalism to compare different prosthetic hands to a human hand based on a function-vector for each prosthesis expressed in terms of a set of functional and geometric characteristics is presented. Function-vector is characterized within a formal context of anthropomorphism. The Biomimetic Similarity Index (BSI) so computed reflects extent of anthropomorphism and allows a quantitative comparison of different prosthetic hands. Biomimetic design leads to higher anthropomorphism and should result in a higher BSI. We explore the case of TU Bionic Hand and compare the BSI for five different prosthetic hands.

Model checking a firewall for anomalies

Abstract: Firewall is the primary network security specified in form of rules that dictate what would and would not be passed to a secured network. Network administrators need to undertake a lot of manual task to get the correct configuration for securing the organization's network resources. Therefore filter properties called anomalies that hint at possible misconfigurations have been introduced. Verification of firewalls for identification of anomalies is a challenging task. We propose to do this within a formal framework using a custom built model checker.

A Two Layered Control Architecture for Prosthetic Grasping

Abstract: Abstract This paper presents a two layered control architecture - Superior hand control (SHC) followed by Local hand control (LHC) for an extreme upper limb prosthesis. The control architecture is for executing grasping operations involved in 70% of daily living activities. Forearm electromyogram actuated SHC is for recognition of user’s intended grasp. LHC control the fingers to be actuated for the recognized grasp. The finger actuation is controlled through a proportionalintegral- derivative controller customized with fingertip force sensor. LHC controls joint angles and velocities of the fingers in the prosthetic hand. Fingers in the prosthetic hand emulate the dynamic constraints of human hand fingers. The joint angle trajectories and velocity profiles of the prosthetic hand finger are in close approximation to those of the human finger

Local Hand Control for Tezpur University Bionic Hand Grasping

Abstract: Tezpur University (TU) Bionic Hand is a biomimetic extreme upper limb prosthesis. The Hand is intended to emulate grasping operations involved during 70% of daily living activities and have been developed using a biomimetic approach. This paper focus on the development of a local hand control for grasping by TU Bionic Hand. Grasp primitives: finger joint angular positions and joint torques are derived through kinematic and dynamic analysis. TU Bionic Hand emulates the grasp types following the dynamic constraints of human hand. The joint angle trajectories and velocity profiles of the Hand finger are in close approximation to those of the human finger.

An Application of Defeasible Logic Programming for Firewall Verification and Reconfiguration

Abstract: Firewalls are the frontier defense in network security. Firewalls provide a set of rules that identify how to handle individual data packets arriving at the network. Firewall configuration is increasingly becoming difficult. Filter properties called anomalies hint at possible conflicts between rules. An argumentation framework could provide ways of handling such conflicts. Verification of a firewall involve finding out whether anomalies exist or not. Reconfiguration involves removing critical anomalies discovered in the verification phase. In this paper, we show how a Defeasible Logic Programming approach with an underlying argumentation based semantics could be applied for verification and reconfiguration of a firewall.

Solving a Maze: Experimental Exploration on Wayfinding Behavior for Cognitively Enhanced Collaborative Control

Abstract: The work described in this paper stems from the Cognitive Wheelchair Project - an effort to build a cognitively enhanced collaborative control architecture for an intelligent wheelchair. A number of challenges arises when developing such a system including ensuring indiscernibility of assistance provided by the system i.e., user unable to realize so easily that he is getting help. In this paper, our focus is primarily on design of such a reactive navigator for collaborative control of an intelligent wheelchair. Under conditions attuned to replicate the scenarios available to the wheelchair, we conducted a series of maze solving experiments. A set of design elements were extracted from the wayfinding experiment leading to the finite state machine (FSM) characterizing the reactive navigator. The FSM arrived at through such an exercise is expected to emulate the cognitive processes of human wayfinding under environment conditions as perceivable to an intelligent wheelchair and ensure indiscernibility of assistance.

Development of A Biomimetic Prosthetic Finger

Abstract: The focus of this paper is on the development of a prosthetic finger prototype following a biomimetic approach. Electromyogram signals are used to actuate the prototype performing flexion-extension and abduction-adduction. Finger joints' torque are transmitted through an antagonastic tendon system. The prototype replicates the dimensions and joint range motion of the human finger.

NAODV-Distributed Packet Dropping Attack Detection in MANETs

Abstract: ad hoc network (MANET) is a self configuring network in which mobile nodes are connected by wireless link. Communication in MANET is done with the help of cooperation of nodes in the network. Due to its intrinsic properties like dynamic network topology, open medium, lack of central monitoring system, these are vulnerable to several attacks. Out of different attacks, packet dropping attack is considered as one of the serious threats as in this kind of attack, malicious node invariably drops the packets which are supposed to be forwarded to destination. Thus, it degrades network performance. In this paper, a distributed packet dropping attack (PDA) detection methodology named NAODV, is proposed. Detection and isolation of malicious node is based on cooperative participation of nodes involved in communication based on TRUST level of the nodes. TRUST levels of the nodes are dynamically updated based on their qualitative participation in detection of malicious nodes. Performance of this methodology is evaluated through simulation in different network scenarios and results are compared with two existing methodologies. KeywordsPDA, distributed packet dropping attack, TRUST,

A rule relation calculus for verification and validation of firewalls

Abstract: Rule based filter is a set of ordered filtering rules. Each rule is formed of a condition and an action. Condition is a set of network fields and can be seen as points in a topological space. Consequently each firewall rule can be seen as a region within the space of filtering fields. Anomalies are relations between rules that hint at possible misconfiguration of firewalls. In this paper, we put forward a calculus that analyzes the topological relationship between firewall rules. Anomalies are definable in the calculus. Within this framework, a constraint satisfaction technique is proposed to reconfigure an anomalous firewall.

A framework for recognition of motion events using qualitative knowledge

Abstract: In this paper, we have proposed a framework for representation and recognition of motion events between two or more objects. The framework combines qualitative spatial abstractions with the technique of syntactic pattern recognition in order to recognize motion patterns in an input stream. The key feature of the framework is recognition of motion events among multiple objects and handling of temporal constraints among events.

Brain Computer Interface as Sensor for Ambient Intelligent Living: A Position Paper

Abstract: Ambient Intelligence (AmI) is about an intelligent environment being aware of the human that interacts with it. Brain Computer Interface (BCI) is part of physiological computing wherein signals from the brain is made to control external devices. One of the major concerns within AmI is to address the issue of user adaptability through a range of intelligent sensors so as to assist the human proactively in his activities and achieving his goals. Towards this end, BCI can be seen as an intelligent sensor for Ambient Intelligent Living. This position paper introduces work being carried out at Tezpur University in pursuit of these goals. Keywords— brain computer interface, intelligent assistive system, intelligent sensor. motor control commands, either directly to control a prosthetic limb or deliver natural motor control of muscles via functional electrical stimulation. BCI could be invasive and non-invasive. Non-invasive approaches are preferred over invasive ones. Within noninvasive BCI, researchers have investigated use of Magneto Encephalography [4], Near Infrared Spectroscopy [5], functional Magnetic Resonance Imaging [6] to measure brain activity. The most widely used non-invasive BCI is by far based on EEG signals [7]. Traditionally BCI research has largely been aimed at users with severe motor impairments, enabling them to interact with the outside world.

A topological calculus for firewalls

Abstract: Firewalls are rule based filters, composed of a sequence of rule. Each rule has a condition and an action. The condition is made up of network fields that can be seen as points in a topological space. Thus, firewall rule conditions can be seen as regions within a topological space. In this paper, we propose a topological calculus and exhaustively analyze all possible configurations to identify the topological relationships that can exist between a pair of firewall rules. Anomalies are properties of firewalls that hint at possible misconfigurations within the firewall. Anomalies including all those that are identified in literature are definable within the calculus.

Recognition of motion events of directed points using a language based framework

Abstract: In this paper, we have proposed a framework for representation and recognition of motion events of spatial objects abstracted as directed points. The framework combines qualitative spatial reasoning with formal grammars in order to recognize motion events in an input stream. Motion events are represented by three qualitative attributes, namely, orientati on, direction and distance. It has been shown that by using spatio-temporal continuity of qualitative relations, it is possible to use regular grammars for event recognition. The novelty of the approach is that any number of qualitati ve relation sets can be combined with formal grammars and hierarchies of abstractions can be created to make the knowledge representation closer to human cognition.

Completion of qualitative spatio-temporal explanations using context

Abstract: Occlusion of objects during spatio-temporal phenomena such as navigation is common for intelligent autonomous systems in a domain with real world objects. Enabling to fill gaps in observation as human do, can enhance the cognition and adaptability of autonomous system multifold. Most cognitive process are contextual. The essence of context in our everyday commonsense reasoning cannot be ignored. Further, everyday spatial and temporal reasoning is qualitative rather than quantitative. Building on work done in the area of qualitative spatial and temporal reasoning, we present an approach for completion of qualitative spatio-temporal explanations using context.