One-dimensional partitioning for heterogeneous systems: Theory and practice

We study the problem of one-dimensional partitioning of nonuniform workload arrays, with optimal load balancing for heterogeneous systems. We look at two cases: chain-on-chain partitioning, where the order of the processors is specified, and chain partitioning, where processor permutation is allowed. We present polynomial time algorithms to solve the chain-on-chain partitioning problem optimally, while we prove that the chain partitioning problem is NP-complete. Our empirical studies show that our proposed exact algorithms produce substantially better results than heuristics, while solution times remain comparable.     

Wavelet domain association rules for efficient texture classification

The wavelet domain association rules method is proposed for efficient texture characterization. The concept of association rules to capture the frequently occurring local intensity variation in textures. The frequency of occurrence of these local patterns within a region is used as texture features. Since texture is basically a multi-scale phenomenon, multi-resolution approaches such as wavelets, are expected to perform efficiently for texture analysis. Thus, this study proposes a new algorithm which uses the wavelet domain association rules for texture classification. Essentially, this work is an extension version of an early work of the Rushing et al. [10], [11], where the generation of intensity domain association rules generation was proposed for efficient texture characterization. The wavelet domain and the intensity domain (gray scale) association rules were generated for performance comparison purposes. As a result, Rushing et al. [10], [11] demonstrated that intensity domain association rules performs much more accurate results than those of the methods which were compared in the Rushing et al. work. Moreover, the performed experimental studies showed the effectiveness of the wavelet domain association rules than the intensity domain association rules for texture classification problem. The overall success rate is about 97%.     

Hypergraph Models and Algorithms for Data-Pattern-Based Clustering

In traditional approaches for clustering market basket type data, relations among transactions are modeled according to the items occurring in these transactions. However, an individual item might induce different relations in different contexts. Since such contexts might be captured by interesting patterns in the overall data, we represent each transaction as a set of patterns through modifying the conventional pattern semantics. By clustering the patterns in the dataset, we infer a clustering of the transactions represented this way. For this, we propose a novel hypergraph model to represent the relations among the patterns. Instead of a local measure that depends only on common items among patterns, we propose a global measure that is based on the cooccurences of these patterns in the overall data. The success of existing hypergraph partitioning based algorithms in other domains depends on sparsity of the hypergraph and explicit objective metrics. For this, we propose a two-phase clustering approach for the above hypergraph, which is expected to be dense. In the first phase, the vertices of the hypergraph are merged in a multilevel algorithm to obtain large number of high quality clusters. Here, we propose new quality metrics for merging decisions in hypergraph clustering specifically for this domain. In order to enable the use of existing metrics in the second phase, we introduce a vertex-to-cluster affinity concept to devise a method for constructing a sparse hypergraph based on the obtained clustering. The experiments we have performed show the effectiveness of the proposed framework.     

Active node determination for correlated data gathering in wireless sensor networks

In wireless sensor network applications where data gathered by different sensor nodes is correlated, not all sensor nodes need to be active for the wireless sensor network to be functional. Given that the sensor nodes that are selected as active form a connected wireless network, the inactive sensor nodes can be turned off. Allowing some sensor nodes to be active and some sensor nodes inactive interchangably during the lifecycle of the application helps the wireless sensor network to have a longer lifetime. The problem of determining a set of active sensor nodes in a correlated data environment for a fully operational wireless sensor network can be formulated as an instance of the connected correlation-dominating set problem. In this work, our contribution is twofold; we propose an effective and runtime-efficient iterative improvement heuristic to solve the active sensor node determination problem, and a benefit function that aims to minimize the number of active sensor nodes while maximizing the residual energy levels of the selected active sensor nodes. Extensive simulations we performed show that the proposed approach achieves a good performance in terms of both network lifetime and runtime efficiency.     

Fatty acid composition and sensory properties of Wels catfish (Silurus glanis) hot smoked with different sawdust materials

This study aims to compare chemical, physical and sensorial parameters of the Wels catfish (Silurus glanis), hot smoked using vine, poplar, lemon tree and oak sawdust as well as corncob. Significant differences (P < 0.05) in proximate composition were found between fresh and smoked samples; however, the changes in fatty acid composition were less significant. In the fatty acid composition of control group, monounsaturated fatty acids (41.60%) had the highest share in fatty acids, which was followed by saturated fatty acids (29.95%) and polyunsaturated fatty acids (28.34%). The major fatty acids were observed to be C16:0, C18:0; C16:1 n‐7, C18:1 n‐9c, C18:1 n‐9t and C18:2 n6c. There were significant differences (P < 0.05) between the groups considering their colour measurement results. General preference criteria such as appearance, odour, texture, colour and taste were chosen for the sensorial analysis, which were rated by the panellists. According to the results of overall appearance, the fillet pieces smoked with lemon tree (9.00), poplar (8.66), corncob (8.00), oak (7.33) and vine (5.33) sawdust were determined as the most preferred, in order.     

A decision support system for locating weapon and radar positions in stationary point air defence

In this study, a decision support system (DSS) based on the interactive use of location models and geographical information systems (GIS) was developed to determine the optimal positions for air defence weapons and radars. In the location model, the fire units are considered as the facilities to be located and the possible approach routes of air vehicles are treated as demand points. Considering the probability that fire by the units will miss the targets, the objective of the problem is to determine the positions that provide coverage of the approach routes of the maximum number of weapons while considering the military principles regarding the tactical use and deployment of units. In comparison with the conventional method, the proposed methodology presents a more reliable, faster, and more efficient solution. On the other hand, owing to the DSS, a battery commander who is responsible for air defence becomes capable of determining the optimal weapon and radar positions, among the alternative ones he has identified, that cover the possible approach routes maximally. Additionally, he attains the capability of making such decisions in a very short time without going to the field over which he will perform the defence and hence without being subject to enemy threats. In the decision support system, the digital elevation model is analysed using Map Objects 2.0, the mathematical model is solved using LINGO 4.0 optimization software, and the user interface and data transfer are supported by Visual Basic 6.0.     

Antioxidative and antimicrobial activities of shrimp chitosan on gilthead sea bream (Sparus aurata) during refrigerated storage

This study aims to determine the effects of chitosan obtained from Metapenaeus stebbingi shells on the shelf life of refrigerated gilthead sea bream. It was determined that 1% chitosan‐coated samples had the lowest thiobarbituric acid (TBA) (3.05 mg malondialdehyde (MDA) kg^?1) and free fatty acids (FFA) value (2.79% oleic acid), while the control group had the highest TBA (5.08 mg MDA kg^?1) and FFA value (6.13% oleic acid) on the 27th day of storage. In the last day of storage, TVB‐N was found higher in control group (25.62 mg 100 g^?1) than chitosan‐coated samples (14.57 mg 100 g^?1). Total viable count value of the control group exceeded maximum permissible limit on the 27th day of storage. However, it was lower than 7.0 log CFU/g in chitosan‐coated samples during the refrigerated storage. As a result of this study, it was determined that shelf life of refrigerated gilthead sea bream can be increased up to 27 days with chitosan.     

All-pole biquadratic filter realization with the minimum ripple due to parameter variations

In this work, the minimization of the ripple in the relative change of the transfer function amplitude due to parameter variations is studied for the signal-flow graph of the state equations realizing all-pole second-order transfer function. First the measure for the ripple is defined and then branch transmittances minimizing the measure are found. the results obtained in this study can be used in all-pole active filter realizations with the minimum ripple measure.     

A Combined Interleaving Technique for Trellis Coded MPSK Systems in Rayleigh Fading Channels

Freedom of mobility is the latesttrend in the evolution of digital communicationsystems. In these systems bandwidth and powerconstraints limit the mobility of the users. TCM(trellis coded modulation) is a combined coding andmodulation scheme which increases the productivity ofa digital communication system without increasing thetransmitted power or the required bandwidth. A mobilecommunication channel is affected from noise andfading because of the multipath propagation. On aRayleigh fading channel, coding should be used withtechniques which uncorrelate the received energy ofeach consecutive coded symbol. Interleaving is one ofthese techniques and used to make burst errors intorandom errors which can be corrected by errorcorrecting codes. In this paper, the trellis codingsystem which combines a regular convolutional encoder,bit interleaver, coordinate interleaver, and anappropriate decoder is considered. The analytical biterror probability upper bounds are derived for the8-PSK TCM system whose diversity is increased by usinga regular 2/3 rate convolutional code followed bythree bit interleavers and a 8-PSK signal mapperfollowed by two coordinate interleavers. Theanalytical and simulation results show that toincrease the diversity of the trellis coded M-PSKsystems in Rayleigh fading channels is the primary keyfor reliable transmission of high quality voice anddigital data.