MacNeish-Mann theorem based iteratively decodable codes for optical communication systems

A novel family of low-density parity-check codes is proposed based on MacNeish-Mann theorem for construction of mutually orthogonal Latin squares. Codes from this family have high code rate, girth at least six, large minimum distance, and significantly outperform conventional forward error correction schemes based on Reed-Solomon (RS) and turbo codes.     

Combinatorial constructions of low-density parity-check codes for iterative decoding

This paper introduces several new combinatorial constructions of low-density parity-check (LDPC) codes, in contrast to the prevalent practice of using long, random-like codes. The proposed codes are well structured, and unlike random codes can lend themselves to a very low-complexity implementation. Constructions of regular Gallager codes based on cyclic difference families, cycle-invariant difference sets, and affine 1-configurations are introduced. Several constructions of difference families used for code design are presented, as well as bounds on the minimal distance of the codes based on the concept of a generalized Pasch configuration.     

COMPARISON OF THE LONG-TERM SECURITY OF SEWAGE-SLUDGE TREATMENT AND DISPOSAL OPTIONS

A comparative 'best practicable environmental option' assessment of fourteen potential sewage-sludge treatment processes and disposal options was undertaken to support the development of Thames Water's sewage-sludge strategy. The assessment was generic in nature and designed to provide comparative performance data on a range of potential process options forming the basis for subsequent site-specific assessments. The study assessed: the relative technical practicability of each process option; the discounted costs of each option (including necessary environmental-mitigation measures); environmental sustainability; and environmental nuisance. The assessment was quantitative wherever possible.
The paper (a) describes the evaluation process. (b) highlights some weaknesses and strengths of the technique, and (c) demonstrates that the technique should form an essential first step in the development of any sludge treatment and disposal strategy.     

Suppression of intrachannel nonlinear effects using pseudoternary constrained codes

In this paper, a novel approach for suppressing the intrachannel nonlinear effects using pseudoternary constrained codes is proposed. A significant Q-factor improvement of up to 9.75 dB is obtained. The eye opening penalty (EOP) is also significantly improved by more than 10.24 dB.     

Shannon capacity of M-ary redundant multitrack runlength limitedcodes

We consider multiamplitude, multitrack runlength-limited (d, k) constrained channels with and without clock redundancy. We calculate the Shannon capacities of these channels and present some simple 100% efficient codes. To compute capacity a constraint graph equivalent to the usual runlength-limited constraint graph is used. The introduced graph model has the vertex labeling independent of number of tracks to be written on (in parallel), which provides computational savings when the number of tracks is large. We show that increasing the number of tracks written on in parallel provides significant increase of per-track capacity for the more restrictive clocking constraint case, i.e., when k相似文献   

The attitude polarization phenomenon: Role of response measure, attitude extremity, and behavioral consequences of reported attitude change.

Four studies examined the generality of attitude polarization (C. G. Lord et al, 1979). Biased assimilation of essays on 2 controversial issues was substantial and correlated with reported attitude change. Polarization was observed for reported attitude change on capital punishment and generally stronger in Ss with extreme than moderate attitudes. Polarization was not indicated in a pre–post measurement design. For affirmative action, reported polarization was not observed. The hypothesis that Ss reporting polarization would subsequently write particularly strong essays was not supported, although those reporting depolarization wrote relatively weak essays. The results suggest the relevance of individual differences in reported attitude change but do not confirm the powerful inferences frequently drawn regarding the pervasive, undesirable consequences of self-reported attitude polarization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Novel combinatorial constructions of optical orthogonal codes for incoherent optical CDMA systems

Three novel classes of optical orthogonal codes (OOCs) based on combinatorial designs are proposed. They are applicable to both synchronous and asynchronous incoherent optical code-division multiple access (OCDMA) and compatible with spectral-amplitude-coding (SAC), fast frequency hopping, and time-spreading schemes. Simplicity of construction, larger codeword families, and larger flexibility in cross-correlation control make the proposed OOC families interesting candidates for future OCDMA applications. A novel balanced SAC receiver for multiuser interference cancellation that can handle unequal in-phase cross correlation of OOC is also proposed. The upper bound on the bit-error rate as a function of the number of users in SAC schemes is given for all proposed OOC classes.     

Plasma surface modifications for improved biocompatibility of commercial polymers

This report describes work using low pressure gas plasma techniques for the fabrication of surfaces designed for compatibility with biological tissue and fluids. The smoothness of the surfaces was investigated using scanning tunnelling microscopy (STM) and the wettability was assessed by measurement of air/water contact angles. Plasma surface treatment rendered fluorocarbon polymers wettable by polar liquids, but the wettability decreased with time during storage of the samples in air. Plasma polymerization, on the other hand, allowed the deposition of thin coatings which were more stable with time. STM of plasma polymers, which were coated with a sputtered film of platinum or gold, showed that these coatings were smooth and continuous. The attachment and growth of human umbilical artery endothelial cells was used to assess the biocompatibility of several plasma polymer surfaces. There was some correlation between the ability of a surface to grow cells and the wettability of that surface with polar liquids, but significant differences in cell growth on surfaces with very similar hydrophilicity indicated that other factors are at least as important.     

Protein profiles and total antioxidant capacity of water‐soluble and water‐insoluble fractions of white brined goat cheese at different stages of ripening

This study deals with proteolysis and total antioxidant capacity of proteins of white brined cheese prepared from overheated goat milk and ripened for fifty days. Proteolytic changes were reflected through the relatively low level of soluble nitrogen (50 days ripened cheese had 15.32 g/100 g of water‐soluble nitrogen, 8.1 g/100 g of TCA‐soluble nitrogen and 2.69 g/100 g of PTA‐SN), intensive proteolysis of α_s2‐CN during initial 10 days of ripening (up to 50.70% of initial content) and its much slower degradation through further 40 days, slow but continual decrease of β‐CN content (up to 85.14% of residual content) and high level of proteolytic products tightly bounded into gel network. Total antioxidant capacity of water‐soluble and water‐insoluble fractions increased after cheese ripening. These findings could be useful for better understanding and control over the production of white brined goat cheese as highly valuable functional product.     

Engineering geological evaluation of the conditions for constructing a bridge and a tunnel in the zone of the old Petrovaradin Fortress,Serbia

The paper discusses the geotechnical conditions related to the construction of a new bridge over the Danube and a tunnel passing beneath the Petrovaradin Fortress at Novi Sad, Serbia. Analyses showed that both the bridge and the tunnel could be built without causing damage to any of the historical structures and that it would better to build two 8 m wide tunnels than a single 16 m wide structure. One of the two tunnels will involve the widening of an existing one, whereas the other will be newly constructed. The evidence suggests that the new bridge can be built on the reinforced piers of a bridge which was destroyed in World War II.