Abstract

The study, conducted in composite climate of India, exhibits improvement in energy efficiency of a conditioned building block with the use of energy conservation measures (ECMs) recommended by National Energy Conservation Building Code (ECBC). In first part of it, subject building model was individually applied with five ECMs and two combinations of these ECMs by using constant thermostat settings. Similarly in second part of the study the same was done with adaptive thermostat settings. Sensitivity analysis showed that the effect of ECMs get reduced with increase in building footprint and internal loads. Analysis of thermal comfort in an unconditioned building using same set of ECMs was also carried out to see improvement in comfort hours.

Abstract

The thermostat control variable in conventional HVAC System is air temprature Ta

Abstract

Online advertising offers significantly finer granularity, which has been leveraged in state-of-the-art targeting methods, like Behavioral Targeting (BT). Such methods have been fur-ther complemented by recent work in Look-alike Modeling(LAM) which helps in creating models which are customized according to each advertiser’s requirements and each cam-paign’s characteristics, and which show ads to users who are most likely to convert on them, not just click them. In Look-a like Modeling given data about converters and non-converters, obtained from advertisers, we would like to train models automatically for each ad campaign. Such custom models would help target more users who are similar to the set of converters the advertiser provides. The advertisers get more freedom to define their preferred sets of users which should be used as a basis to build custom targeting models.In behavioral data, the number of conversions (positive class) per campaign is very small (conversions per impression for the advertisers in our data set are much less than 10−4),giving rise to a highly skewed training dataset, which has most records pertaining to the negative class. Campaigns with very few conversions are called as tail campaigns, and those with many conversions are called head campaigns.Creation of Look-alike Models for tail campaigns is very challenging and tricky using popular classifiers like Linear SVM and GBDT, because of the very few number of posi-tive class examples such campaigns contain. In this paper,we present an Associative Classification (AC) approach to LAM for tail campaigns. Pairs of features are used to deriverules to build a Rule-based Associative Classifier, with the rules being sorted by frequency-weighted log-likelihood ratio(F-LLR). The top krules, sorted by F-LLR, are then applied to any test record to score it. Individual features can also form rules by themselves, though the number of such rules in the top krules and the whole rule-set is very small. Our algorithm is based on Hadoop, and is thus very efficient in terms of speed.

Abstract

IGIPT is a web-based integrated platform for the identification of genomic islands (GIs). It incorporates thirteen parametric measures based on anomalous nucleotide composition on a single platform, thus improving the predictive power of a horizontally acquired region, since it is known that no single measure can absolutely predict a horizontally transferred region. The tool filters putative GIs based on standard deviation from genomic average and also provide raw output in MS excel format for further analysis. To facilitate the identification of various structural features, viz., tRNA integration sites, repeats, etc. in the vicinity of GIs, the tool provides option to extract the predicted regions and its flanking regions.

Abstract

Three decades ago, Pease et al. introduced the problem of Byzantine Agreement [PSL 80] where nodes need to maintain a consistent view of the world in spite of the challenge posed by Byzantine faults. Subsequently, it is well known that Byzantine agreement over a completely connected synchronous network of n nodes tolerating up to t faults is (efficiently) possible if and only if t < n/3. Pease et al. further empowered the nodes with the ability to authenticate themselves and their messages and proved that agreement in this new model (popularly known as authenticated Byzantine agreement (ABA)) is possible if and only if t < n. (which is a huge improvement over the bound of t < n/3 in the absence of authentication for the same functionality). To understand the utility, potential and limitations of using authentication in distributed protocols for agreement, Gupta et al. [GGBS10] studied ABA in new light. They generalize the existing models and thus, attempt to give a unified theory of agreements over the authenticated and non-authenticated domains. In this paper we extend their results to synchronous (undirected) networks and give a complete characterization of agreement protocols. As a corollary, we show that agreement can be strictly easier than all-pair point-to-point communication. It is well known that in a synchronous network over n nodes of which up to any t are corrupted by a Byzantine adversary, BA is possible only if all pair point-to-point reliable communication is possible [Dol82, DDWY93]. Thus, a folklore in the area is that maintaining global consistency (agreement) is at least as hard as the problem of all pair point-to-point communication. Equivalently, it is widely believed that protocols for BA over incomplete networks exist only if it is possible to simulate an overlay-ed complete network. Surprisingly, we show that the folklore is not always true. Thus, it seems that agreement protocols may be more fundamental to distributed computing than reliable communication.

Abstract

In the Perfectly Secure Message Transmission (PSMT) problem, a sender S and a receiver R are part of a distributed network and connected through node disjoint paths, also called as wires, among which at most wires are controlled by a static, Byzantine adversary , having unbounded computing power. S has a message , which S intends to send to R. The challenge is to design a protocol, such that at the end of the protocol, R should correctly output without any error (perfect reliability) and should not get any information about , whatsoever, in information theoretic sense (perfect security). The problem of Statistically Secure Message Transmission (SSMT) is same as PSMT, except that R should correctly output with very high probability. Sayeed and Abu-Amara (1995) [37] have given a PSMT protocol in an asynchronous network tolerating , where S and R are connected by wires. However, we show that their protocol does not provide perfect security. We then prove that in an asynchronous network, if all the wires are directed from S to R, then any PSMT protocol tolerating is possible iff . Surprisingly, we also prove that even if all the wires are bi-directional, then any PSMT protocol in asynchronous network tolerating is possible iff . This is quite surprising because for synchronous networks, by the results of Dolev et al. (1993) [16], if all the wires are unidirectional (directed from S to R), then PSMT tolerating is possible iff , where as if all the wires are bi-directional then PSMT tolerating is possible iff . This shows that asynchrony of the network demands higher connectivity of the network for the existence of PSMT protocols. Interestingly, we further show that wires are necessary and sufficient for the existence of any SSMT protocol in asynchronous network tolerating , irrespective of whether the wires are unidirectional from S to R or the wires are bi-directional. By the results of Franklin and Wright (2000) [18] and Kurosawa and Suzuki (2009) [22], wires are necessary and sufficient for the existence of SSMT in synchronous networks, irrespective of whether the wires are unidirectional from S to R or the wires are bi-directional. This shows that asynchrony of the network does not demand higher connectivity of the network for SSMT protocols.

Abstract

In this paper we propose and evaluate Marasim, a novel Jigsaw based graphical authentication mechanism using tagging. Marasim is aimed at achieving the security of random images with the memorability of personal images. Our scheme relies on the human ability to remember a personal image and later recognize the alternate visual representations (images) of the concepts occurred in the image. These concepts are retrieved from the tags assigned to the image. We illustrate how a Jigsaw based approach helps to create a portfolio of system-chosen random images to be used for authentication. The paper describes the complete design of Marasim along with the empirical studies of Marasim that provide evidences of increased memorability. Results show that 93% of all participants succeeded in the authentication tests using Marasim after three months while 71% succeeded in authentication tests using Marasim after nine months. Our findings indicate that Marasim has potential applications, especially where text input is hard (e.g., PDAs or ATMs), or in situations where passwords are infrequently used (e.g., web site passwords).

Abstract

Graphical passwords are considered to be a secure and memorable alternative to text passwords. Users of such systems, authenticate themselves by identifying a subset of images from the set of displayed images. However, despite the impressive results of user studies on experimental graphical passwords schemes, their overall commercial adaptations have been relatively low. In this paper, we investigate the reasons behind the low commercial acceptance of graphical passwords and present recommendations to overcome the same. Based on these recommendations, we design a simple graphical password scheme, which we call as NAPTune. NAPTune is aimed to work as a cued recognition based graphical authentication scheme that allows users to choose both text as well as images as their password with the same underlying design and interaction. In doing so, we blend the strengths of Numbers, Alphabets and Pictures (NAP) together to effectively defeat prevalent forms of social hacking. We conducted a user study with 35 participants to evaluate the viability of our proposed design. Results of the study are encouraging which indicates that our proposed design is potentially secure and usable method of authentication.

Abstract

In this problem, the process start with real-valued inputs and are supposed to decide eventually on real-valued outputs. The process is permitted to send real-valued data in messages. Instead of having to agree exactly, as in the ordinary agreement problem, this time the requirement is just that they agree with within a small positive real-valued tolerance ε. In the standard implementation agreement problem converges to a consistent value for each sensor measurement, which is nonfaculty using Byzantine algorithm with at-least n >; 3 faulty sensors. We define a pre-processing BestBasis cost function which allows to find a coherent range, which can be measured using intra-sensor in an ensemble of real-values. The overlap of the range is calculated by using a clique, with a runtime of O(nk) in the worst-case, where the size of clique, k, is a variable. The computation of the pre-processing takes O log(D), where D is the number of levels in a sparse signal basis. Which are some times analogously compared to needle in a hay stack definition.

Abstract

For voiced speech, the most significant excitation takes place around the instant of glottal closure. Glottal closure in-stants (GCI) information is useful for accurate speech analysis.In particular accurate spectrum analysis is performed by con-sidering the speech in the intervals of glottal closure. In this pa-per we propose an approach for detection of GCI by exploring Bessel feature, and the use of AM-FM signal. Using appropri-ate range of Bessel coefficients, the narrow band, band limited signal is obtained for the given signal.The band limited signal isconsidered as AM-FM signal. The signal is band limited for 0-300 Hz to remove effect of formants. Amplitude envelope (AE)function of the AM-FM signal model has been estimated by the discrete energy separation algorithm (DESA). The performance of the method is demonstrated using CMU-Arctic database. The corresponding electro-glottograph (EGG) signals are used as a reference for the validation of the detected GCI locations.