Search

The modern scientific growths in optical networks based on wavelength division multiplexing (WDM) are more attractive to satisfy the high bandwidth requirements of the modern internet infrastructure. Moreover, they potential to satisfy the future bandwidth requirements.WDM optical networks act as the backbone for telecommunication and high-performance communication networks. Multicast communication is the simultaneous transmission of data from one source node to many destination nodes available in the network over wavelength division multiplexing. It is extensively deployed in high performance computing and communication networks. In this article, a linear array and ring networks are extended by directly linking all nodes which are separated by two intermediate nodes with additional fibers which is referred as linear array and ring network with 3-length extension. The wavelength allotment methods are proposed to realize one-to-many communication over wavelength division multiplexing optical linear array and ring with 2-length extension under longest link first routing and the minimum wavelength number needed is determined. The minimum wavelength number needed to support for the extended linear array is reduced approximately by 20% when compared with that of a linear array network and for the extended unidirectional ring is reduced approximately by 25% when compared with that of a unidirectional ring network. And also, for the extended bidirectional ring the minimum wavelength number is reduced approximately by 33% when compared with that of bidirectional ring network.

Multicast communication is the concurrent transmission of data from one source node to many destination. It is widely deployed in high performance computing and communication networks.In this paper, a linear array and ring networks are extended by directly linking all nodes which are separated by one intermediate node with additional fibers which is referred as linear array and ring network with 2-length extension and wide sense nonblocking multicast is studied. The wavelength allotment methods are proposed to realize one-to-many communication over wavelength division multiplexing optical linear array and ring with 2-length extension under index-based routing and the minimum wavelength number needed is determined. The minimum wavelength number needed to support for the extended linear array and ring topologies is reduced approximately by half when compared with that of a linear array network and ring network.

All-to-all broadcast communication is to transmit a distinctive data from each node to every other node available in the network. This is a fundamental prerequisite in high performance computing and telecommunication networks including enterprises operating datacenters which may spread across thousands of nodes by means of WDM optical networks. Wavelengths are scarce resources in WDM optical networks. Reducing the wavelengths usage is essential to decrease the price and complication of the network. In this article, a ring network is extended by additionally connecting alternate nodes in order to provide alternate paths so as to reduce the effective number of hops between the communicating nodes and also to reduce the wavelength requirements and this network is referred as a ring network with 2-length extension. Similarly, a ring network is extended by directly linking all nodes which are separated by two intermediate nodes with additional fibers and this network is referred as a ring network with 3-length extension. For the ring network with 2-length extension the optimum wavelength number necessary to establish all-to-all broadcast under unidirectional routing is derived by grouping nonoverlapping connections on a common wavelength. The wavelength number necessary atmost to establish all-to-all broadcast in a unidirectional ring with 3-length extension is derived using longest link first routing algorithm.

All-to-all broadcast communication, distributing messages from each node to every other node, is a dense communication pattern and finds numerous applications in advanced computing and communication networks from the control plane to datacenters. A ring network topology is one of the important regular network topologies due to its simple structure, high speed, easy to extend and tolerant to link and node failures. Few researchers recommended connecting the alternate nodes of the ring with additional fibers in the ring network, to support increased call connection probability, higher tolerable to multiple link and node failures, enormous traffic handling capability and improved survivability. To reduce the complicatedness and cost of the network, it is essential to reduce the wavelength-number required to establish all-to-all broadcast in wavelength-division multiplexed ring network. In this paper, a ring network is extended by directly linking all nodes which are separated by two intermediate nodes with additional fibers and this network is referred as ring with 3-length extension. The wavelength allotment methods are proposed for realizing all-to-all broadcast over a WDM optical bi-directional ring with 3-length extension under multiple unicast routing model using a two-stage heuristic algorithm. The heuristic algorithm is developed to identify non-overlapping connections and an explicit wavelength allotment method based on the output of the heuristic technique is given. The result obtained shows that wavelength-number required atmost to establish all-to-all broadcast in a bi-directional ring with 3-length extension is reduced by a minimum of 57% and a maximum of 66% when compared to bi-directional primary ring. Similarly, the wavelength-number required atmost to establish all-to-all broadcast in a bi-directional ring with 3-length extension is reduced by a minimum of 20% and a maximum of 33% when compared to a bi-directional ring with 2-length extension.

All-to-all broadcast communication, distributing messages from each node to every other node, is a dense communication pattern and finds numerous applications in advanced computing and communication networks from the control plane to datacenters. In this article, a linear array is extended by directly linking all nodes which are separated by two intermediate nodes with additional fibers and this network is referred as linear array with 3-length extension. The wavelength allotment methods are proposed to realize all-to-all broadcast over WDM optical linear array with 3-length extension under multiple unicast routing model and the wavelength number needed atmost to establish all-to-all broadcast is determined. The wavelength number needed atmost to establish all-to-all broadcast in a linear array with 3-length extension is reduced by a minimum of 61% and a maximum of 66% when compared to a basic linear array. Similarly, the wavelength number needed atmost to establish all-to-all broadcast is reduced by a minimum of 24% and a maximum of 33% when compared to linear array with 2-length extension.

Multicast communication is the simultaneous transmission of information from a single source to various destinations. It occurs extensively in telecommunication and advanced computing systems including enterprises operating datacenters. WDM optical networks act as the backbone for telecommunication and high performance networks. Wavelengths are scarce resources in WDM optical networks. Wavelengths usage in a network must be limited to decrease its cost and complexity. Optical linear array and ring networks find widespread application in interconnection networks including LAN and WAN. In this paper, wide-sense nonblocking multicast communication is analyzed in wavelength reusable multi-carrier distributed (WRMD) wavelength division multiplexing (WDM) linear array, unidirectional ring and bidirectional ring networks. The sufficient and necessary condition on the minimum wavelength number required for the network to be wide-sense nonblocking is derived for each of the above network topologies in the presence of a single multi-carrier light source (MCLS). An explicit wavelength allotment technique is also proposed for the above network topologies.

All-to-all broadcast is to distribute an exclusive message from each node to all the other nodes in the network. This is a vital requirement in high performance computing and communication networks including datacenter operations. Such networks may spread across thousands of nodes by means of WDM optical networks. A ring topology is an important form of network topology as it is simple, easy to deploy and fault tolerant. Few previous works suggested connecting the alternate nodes of a backbone naive ring network, and called as modified ring to support huge traffic density with decreased delay, reduced call blocking probability and increased survivability. One of the major design issues in wavelength-division multiplexed networks is to aim for reduction in the number of wavelengths usage so as to reduce network cost and complexity. In this paper, for the modified ring network, all-to-all broadcast communication is studied under single hop routing model by means of a heuristic technique, which supports to identify and group non overlapping connections. Explicit wavelength allocation techniques are given to allot unique wavelengths for various groups of non overlapping connections. The results obtained shows that wavelength requirements for a modified ring is considerably reduced than that required for a naive ring network and hence makes it attractive for optical control plane.

During the past two decades, frequent pattern mining (FPM) has acquired the interests of many researchers: which involves extracting the itemsets from transactions, sequences from big dataset, which occurs frequently and to recognize from the molecular structures, the common sub graph. In this big data era, the unpredictable flow and huge quantity of data brings new challenges in FPM such as space and time complexity. In general, most of the research work focus on recognizing the patterns that occurs frequently, from the set of specific data, where the patterns within every transaction were definitely known a priori. Among these, the users focus only on the small part of this FP. In order to tackle such problems in the current scenario, it is necessary sometimes to select the important features alone, using appropriate FPM algorithms, in order to reduce the complexity level. The major objective of this work is to improve FPM mining results and improve classification accuracy of big dataset samples. To tackle the first challenge, the levy flight bat algorithm (LFBA) along with online feature selection (OFS) approach is proposed, which is used to filter the low quality features from the big data in an online manner. Subsequently to address the second challenge, a weighted entropy frequent pattern mining (WEFPM) is enforced for FPM, to accomplish better computation time when compared with other methods such as direct discriminative pattern mining (DDPMine) and iterative sampling based frequent itemset mining (ISbFIM), where enumeration of entire feature combinations were completed. So the WEFPM algorithm employed in this paper, targets to identify only the specific frequent patterns which are required by the user. By iterating this procedure, it assures that the acquired frequent patterns can be enumerated by using both the theoretical and empirical research, so that enumeration doesn’t proceed into a combinatorial explosion. And also, using the above said LFBA–OFS approach and WEFPM algorithm, frequent patterns that are different in nature, are generated for building high quality learning model. For finding the frequent patterns, here the minimum support threshold is matched with entropy. As a final step, multiple Kernel learning support vector machine is employed as a classifier, to evaluate the performance of the big data samples for efficiency and accuracy. Empirical study reveal that considerable progress is obtained in terms of accuracy and computation time when applied to UCI benchmark big datasets, using the proposed approach for efficient and effective FPM of the online features. It is clear that WEFPM is the most efficient method, because it produces higher average accuracy results of 92.34, 93.218, 91.374 and 87.87% values for adult, chess, hybo and sick dataset respectively. It outperforms when compared to other methods such as DDPMine and ISbFIM using an LIBSVM classifier.

Multicast communication is the concurrent transmission of data from one source node to many destination nodes. It is widely deployed in high performance computing and communication networks. In this article, wide-sense nonblocking multicast communication is studied in wavelength division multiplexing networks namely modified linear array, unidirectional and bidirectional modified ring networks. The sufficient and necessary condition on the minimum wavelength number required for the network to be wide-sense nonblocking is derived for each of the above network topologies under longest link first routing technique which employs approximately half the number of hops when compared with networks without modification. An explicit wavelength allotment technique for multicast assignment is also given for each of the above network topologies.

All-to-all broadcast in a network is to distribute an exclusive message from each node to every other node. It is a vital requirement in high performance computing and communication applications including enterprises operating data centers. It is also a core issue in telecommunication network where each node in the network needs to gather information about all the other nodes for efficient management of network resources. WDM optical networks act as the backbone for telecommunication networks. Wavelengths are precious resources in WDM optical networks and its usage must be limited to reduce network cost and complexity. Optical linear array finds application in LAN, WAN and MAN and its topology needs to be modified to reduce wavelength requirements and hop count. In this paper, a linear array network is modified by additionally joining alternate nodes. For such a modified linear array, the minimum wavelength number needed to support all-to-all broadcast is derived by grouping non overlapping connections on a common wavelength. The results obtained for modified linear array shows that the wavelength number needed is approximately reduced by half when compared with that of a linear array.

In the recent times, several disciplines have to tackle with huge datasets, which are involved with a huge number of additional features. Feature Selection (FS) techniques target at reducing the noisy, redundant, or unnecessary features, which might degrade the performance of classification. Although there is several numbers of FS techniques, still it remains an active research field among the data mining, machine learning and pattern recognition groups. Several FS techniques are imposed with critical issues with regards to efficiency and usefulness, due to rise in data dimensionality, which happens nowadays. Nonetheless, conventional techniques are deficit of sufficient scalability to deal with datasets consisting of millions of instances and obtain results with success in a less amount of time. Therefore, in this case, an Online Feature Selection (OFS) algorithm can yield a better solution for solving this issue. This work reviews few of the available and well-known FS, OFS techniques by pointing out the pros and cons of those techniques. This technical work studies the details of traditional FS and OFS techniques depending on evolutionary computation that is helpful in getting the subsets of features from huge datasets. As a result, this review also provides a summary, and analysis of machine learning algorithms for huge datasets. In addition, the new machine learning strategies and methodologies are explained with their capacity of dealing with the different challenges with the ultimate goal of assisting the practitioners in selecting the suitable solutions for their use cases. This review work renders a view on the big data domain, finds the research gaps and possibilities, and offers a solid foundation, assistance for more research in the machine learning field that uses big dataset.

Burst loss ratio is the important factor in Optical Burst switching (OBS) networks. When the burst entering the source node, finds the server free it reserves the server and gets transmitted immediately. In case that the server is blocked, the incoming burst waits in the buffer available in the source node of the selected pair and tries retransmission till it reaches the destination successfully. In this paper, we studied a method which combines buffering and retransmission to resolve contention and the effect of maintenance activity and buffer search of the server on the bursts being handled (processed) in the network.

In WSNs, failures are unavoidable due to the inhospitable environment and unattended deployment. The node failure leads to disconnection from the network and causes network partitioning. We propose to develop a fault detection and recovery scheme where the sink generates an agent packet and the Agent forms a query path towards the dead or faulty node. Here, sink periodically broadcasts the Agent packet to all its neighbor nodes. The receiving node randomly makes a decision as whether to forward the packet or not thereby detecting the dead or faulty nodes. After detecting a node failure or dead node, the connectivity is restored using Least-Disruptive Topology Repair (LeDiR) without extending the length of the shortest path among nodes compared to the pre failure topology. LeDiR replaces the faulty node with block movement.

In recent times, the demand for real-time multimedia applications is rapidly increased due to the increasing mobile users. Wireless Sensor Network (WSN) often suffers because of the overhead produced during message passing, constant energy and node cost. To provide solution to these issues, in this study, we propose Fuzzy and Gravitational Search Based Routing Protocol for Lifetime Enhancement in WSN. Gravitational Search Algorithm (GSA) is used for searching the paths. As GSA finds the global optimum faster, it has higher convergence rate. An improved routing technique is proposed for lifetime enhancement in WSN. For estimating the node cost using fuzzy logic, the parameters such as link quality and distance from the sink node, residual energy and load are used. Simulation results prove that the proposed protocol performs well compared to the existing protocols.

All-to-all broadcast is to disseminate a unique message from each node to every other node in a network. This problem is significant in the context of control plane design as it relates to status information dissemination. In this paper, a wavelength assignment method to reduce the number of wavelengths is proposed to establish all-to-all broadcast in a bidirectional WDM ring network. The network model is an all-optical network, in which a message from source node can be dropped (or split) only at a limited number of destination nodes along a light path due to power loss of dropping optical signals. An expression for the upper bound on the number of wavelengths required to support all-to-all broadcast is derived for certain cases of WDM ring while for other cases, an attractive algorithm is given to identify the lengths of connection sets that can be grouped together with suitable wavelength assignment strategies. Numerical results are computed to show that the results obtained are close to the lower bound.

Template security of biometric systems is a vital issue and needs critical focus. The importance lies in the fact that unlike passwords, stolen biometric templates cannot be revoked. Hence, the biometric templates cannot be stored in plain format and needs strong protection against any forgery. In this paper, we present a technique to generate face and palm vein-based fuzzy vault for multi-biometric cryptosystem. Here, initially the input images are pre-processed using various processes to make images fit for further processing. In our proposed method, the features are extracted from the processed hand and palm vein images by finding out unique common points. The chaff points are added to the already extracted points to obtain the combined feature vector. The secret key points which are generated based on the user key input (by using proposed method) are added to the combined feature vector to have the fuzzy vault. For decoding, the multi-modal biometric template from palm vein and hand vein image...

ECG signals are non-stationary pseudo periodic in nature and whose behavior changes with time. The proper processing of ECG signal and its accurate feature extraction is very much essential since it determines the condition of the heart. Least mean square (LMS) based adaptive filters are widely deployed for removing artifacts in ECGs due to less number of computations. But they posses high mean square error (MSE) under noisy environment. The MSE can be reduced by transform domain variable step size LMS algorithm at the cost of computational complexity. In this paper, a variable step size delayed LMS adaptive filter is used to remove the artifacts from ECG signal for improved feature extraction. Moreover, the extraction of R peak in ECG is carried out using discrete wavelet transform based QRS detection algorithm. Due to the high speed of our method, the ECG de-nosing and R Peak extracting could be both realized at real time, which is an effective method to monitor the patients in biotelemetry applications.

This paper proposes a wavelength assignment method for all-to-all broadcast in wavelength reusable multi-carrier distributed (WRMD) wavelength division multiplexing (WDM) linear array and ring networks with wavelength reuse. An expression on the minimum number of wavelengths required to establish all-to-all broadcast is also derived for the networks. It is observed that one carrier regeneration per wavelength significantly reduces the number of wavelengths compared to that without carrier regeneration. The results also show that regenerating carriers more than once has little effect on the required number of wavelengths.

In the human race, 70 % of energy is devoured by electric motors. This rate may be expanded because of the growth of power electronic devices and the fast advancement of automation technology. Most assembling units overall depend on electric motors for their generation, therefore highlighting the requirement for a viable speed control motors to build creation. It is underlined power electronic devices innovation has encountered a dynamic improvement in the previous four decades. As of late, its applications are quick growing in modern, business, private, transportation, utility, aviation and military situations, principally because of the lessening of expense, size, and performance enhancement. Soft computing techniques, especially the neural systems are having as of late huge effect on electrical drives and power devices. Neural systems have created another new edge and development power devices, that is currently a fancy and multidisciplinary innovation that goes through the dynamic improvement as lately. In this article, the significance of power hardware, the late advances in power semiconductor devices, converters, AC motors with variable frequency, the dawn of microprocessors/microcontrollers/microcomputers permitted to actualize and these control methods will be discussed briefly.

All-to-all broadcast is to disseminate a unique message from each node to every other node. This is a fundamental problem in multiprocessor systems and telecommunication networks that need to collect information about other nodes in the network regularly in order to manage network resources efficiently. In this paper, a novel wavelength assignment method is proposed to establish all-to-all broadcast in a linear array network. The network model is an all-optical network, in which a message from source node can be dropped (or split) only at a limited number of destination nodes along a light path due to power loss of dropping optical signals. The minimum number of wavelengths required to establish all-to-all broadcast is also derived for a linear array network.

All-to-all broadcast communication is to disseminate a unique message from each node to every other node in a network. This is a fundamental problem in multiprocessor systems and telecommunication networks that need to collect information about other nodes in the network regularly in order to manage network resources efficiently. It is known that in wavelength division multiplexing (WDM) optical networks with single hop routing, the number of wavelengths needed for realizing all-to-all broadcast is quite large, even for a moderately sized network. One possible method to reduce the number of wavelengths is to adopt a network with drop-and-continue capable nodes. In such networks, a message from a source node can be dropped only at a limited number of destination nodes along a light path due to power loss of the dropping optical signals at the destination nodes. In this paper, a new wavelength assignment method is proposed to establish all-to-all broadcast in unidirectional ring and bi-directional ring networks which contain drop-and-continue capable nodes. An upper bound on the number of wavelengths required to establish all-to-all broadcast is also derived for unidirectional ring and bi-directional ring.

This paper addresses the problem of routing and wavelength requirements for all-to-all broadcast communication in wavelength division multiplexed optical networks. The network model is an all-optical network, in which a message can be split and dropped to all destination nodes along a light-tree. A tight bound on the minimum number of wavelengths required to establish all-to-all broadcast communication for various topologies is presented. The optimal routing and wavelength assignment algorithms for all-to-all broadcast to achieve the minimal number of wavelengths are also described for these topologies under both the presence and absence of wavelength conversion.

For the past several years a significant amount of research has been conducted in the area of Optical Burst Switching (OBS) networks. This research has been motivated by the need for the promising solution to minimize the burst loss ratio in OBS networks. The analysis of Optical Burst Switching networks with buffering and retransmission is considered. On arrival of the bursts if the wavelength is free, one of the burst occupies it and remaining enters the buffer for retransmission. Otherwise all the bursts enter the buffer. There are three essential hops provided to each burst to reach the destination. After a burst reaches the destination, the server may go for a maintenance activity or wait for the arrival of the new burst. We model it as a single wavelength retransmission queuing system using supplementary variable technique. Various parameters are derived. Numerical results are obtained using MATLAB.

Burst contention is a major problem in the Optical Burst Switching (OBS) networks. Due to inadequate contention resolution techniques, the burst loss is prominent in OBS. In order to resolve contention fiber delay lines, wavelength converters, deflection routing, burst segmentation, and retransmission are used. Each one has its own limitations. In this paper, a new hybrid scheme is proposed which combines buffering and retransmission, which increases the mean number of bursts processed in the system. In this hybrid method, retransmission with controllable arrival and uncontrollable arrival is analyzed. Normally all the bursts reach the first hop and few of them go for second hop to reach destination. After all the bursts reach the destination the server may go for maintenance activity or wait for the arrival of next burst. We model it as a batch arrival single server retrial queue with buffer. Numerical results are analyzed to show the mean number of bursts processed in the system with uncontrollable arrival and controllable arrivals.

Biometric recognition is noteworthy method for recognition of person in recent years. Here, a common concern is biometric security which is the privacy issues derived from storage and misuses of the template data. In order to handle this issue, researches have proposed different algorithms to be confronted by security of biometric systems. Two major ways are, (1) Encryption, and (2) watermarking by securing biometric images and templates. In this paper, we utilise a watermarking technology to improve the template security in biometric authentication. According to, two modalities such as, iris and hand vein is taken to preserve the characteristics of liveliness and permanency. Our proposed technique for embedding of iris data to hand vein images using watermarking technology to improve template protection in biometric recognition is done based on the following steps, i) pre-processing of iris and hand vein images, ii) iris template extraction, iii) Vein extraction, iv) Embedding of iris pattern to vein images based on region of interest, v) Storing embedded images. In the recognition phase, iris pattern is extracted from the embedded image and then, matching is done with query images. The final decision of authentication is done based on the product rule-based score level fusion. The implementation is done using MATLAB and the performance of the technique is analysed with FAR, FRR and accuracy.

Wavelength-division multiplexing (WDM) optical networks provide huge bandwidth by allowing multiple data strams transmitted simultaneously along the same optical fiber, with each stream assigned a distinct wavelength. An important issue in optical WDM networks is to minimize the number of wavelengths required for communication. All-to-All broadcast is a fundamental communication application on computer/communication networks. In this paper, we provide the method of assigning wavelengths for all-to-all broadcast communication in optical WDM hypercube network without light splitters under e-cube routing algorithm. We also find the minimum number of wavelengths required to support all-to-all broadcast communication.

Much research is taking place in the field of motor drives, especially in the area of permanent magnet brushless DC motors (PMBLDC).This paper dealt with developing a Simulink model for PMBLDC motor drive systems with a high-performance, improved brain emotional-learning based intelligent controller (IBELBIC) using MATLAB/Simulink to control the speed and torque of the machine. To enhance the performance of PMBLDC motor, two control loops were employed for control of current and speed, respectively. Though the conventional PI controller may be used to control the speed of PMBLDC motor, the stability of the machine under changing loads cannot be ensured. Therefore, IBELBIC with a tracking system for the speed loop is proposed in this paper. It has been ascertained for the first time that the speed and torque performance of the system is enhanced by IBELBIC with minimum processing time. The contribution of this novel IBELBIC in improving the control system performance is shown by comparison with results obtained from classic PI controller, fuzzy PI controller, anti-windup PI controller, and IBELBIC. The results suggested that IBELBIC-based PMBLDC motor drive was more versatile for variable speed applications. The validation of the simulation was provided by a 400 W PMBLDC motor and drive system using Spartan 3 FPGA (Field Programmable Gate Array) based prototype, which is generally suitable for dedicated implementations of design and ease of redesign. The LABVIEW-based customized program was developed on a computer to monitor the motor performance.

Wireless sensor network consists of sensor nodes with sensing and communication capabilities. Typical communication model of wireless sensor network consists of several sensor nodes as group members, sensor head and sinks. Past few years have witnessed increased in the potential use of Wireless Sensor Network (WSN) such as military surveillance, tracking and monitoring, disaster management and combat field reconnaissance. Many issues in WSN are formulated as multidimensional optimization problem and solved through energy based distributed clustering techniques [1]. The main problem in WSN is the lifetime of network. To support scalability, nodes are often grouped in clusters having a leader, often referred as Sensor Head (SH). A SH is responsible for not only sending data to base station but also assists the general nodes to send sensed data to target nodes. The energy consumption of SH is greater than general nodes. Therefore SH selection will affect the lifetime of WSN and also support packet loss. This proposed approach is based on Energy-Balanced Distributed Clustering (EBDC) [2–3] algorithm. Honey bee optimization with some parameters is employed over EBDC algorithm for effective dynamic cluster head selection. This approach helps in increasing the energy consumption. This proposed technique works in three stages: Cluster nodes send data to SH, SH sends data directly to leader and leader sends data to Base Station (BS). Sensor Head (SH) has responsibility to select neighbor node as a Sub Sensor Head (SSH) to reduce overload. Simulations results demonstrate that EBDC-HBO algorithm improves the life time of network.

This paper addresses the problem of wavelength requirements for all-to-all broadcast communication in wavelength division multiplexed optical networks. The network model is an all-optical network, in which a message can be split and dropped to all destination nodes along a light-tree. A tight bound on the minimum number of wavelengths required to establish all-to-all broadcast communication for various topologies is presented. The optimal routing and wavelength assignment algorithms for all-to-all broadcast to achieve the minimal number of wavelengths are also described for these topologies

A novel wavelength assignment method is proposed for a bidirectional WDM ring network and the minimum number of wavelengths required to support all-to-all broadcast is determined. The new method can assign each wavelength directly and simultaneously to a group of non-overlapping connections on an N-node ring without the aid of any table or matrix. The presented wavelength assignment method is much faster than other direct methods with explicit formulas previously reported for WDM ring network.

A novel wavelength assignment algorithm based on the method of optimal grouping of non-overlapping connections is proposed for a linear array network. A tight bound on the minimum number of wavelengths required to support all-to-all broadcast is derived for the linear array under the presence and absence of wavelength conversion facilities.

Template security of biometric systems is a vital issue and needs critical focus. The importance lies in the fact that unlike passwords, stolen biometric templates cannot be revoked. Hence, the biometric templates cannot be stored in plain format and needs strong protection against any forgery. In this paper, we present a technique to generate face and palm vein-based fuzzy vault for multi-biometric cryptosystem. Here, initially the input images are pre-processed using various processes to make images fit for further processing. In our proposed method, the features are extracted from the processed face and palm vein images by finding out unique common points. The chaff points are added to the already extracted points to obtain the combined feature vector. The secret key points which are generated based on the user key input (by using proposed method) are added to the combined feature vector to have the fuzzy vault. For decoding, the multi-modal biometric template from palm vein and face image is constructed and is combined with the stored fuzzy vault to generate the final key. Finally, the experimentation is conducted using the palm vein and face database available in the CASIA and JAFFE database. The evaluation metrics employed are FMR (False Match Ratio) and GMR (Genuine Match Ratio). From the metric values obtained for the proposed system, we can infer that the system has performed well.