Adaptive Methods for Linear Programming Decoding

Detectability of failures of linear programming (LP) decoding and the potential for improvement by adding new constraints motivate the use of an adaptive approach in selecting the constraints for the underlying LP problem. In this paper, we make a first step in studying this method, and show that it can significantly reduce the complexity of the problem, which was originally exponential in the maximum check-node degree. We further show that adaptively adding new constraints, e.g. by combining parity checks, can provide large gains in the performance.Comment: 22 pages, 8 figures. Submitted to IEEE Transactions on Information Theor

Graph-Based Decoding in the Presence of ISI

We propose an approximation of maximum-likelihood detection in ISI channels based on linear programming or message passing. We convert the detection problem into a binary decoding problem, which can be easily combined with LDPC decoding. We show that, for a certain class of channels and in the absence of coding, the proposed technique provides the exact ML solution without an exponential complexity in the size of channel memory, while for some other channels, this method has a non-diminishing probability of failure as SNR increases. Some analysis is provided for the error events of the proposed technique under linear programming.Comment: 25 pages, 8 figures, Submitted to IEEE Transactions on Information Theor

The diet of big-scale sand smelt Atherina boyeri caspia (Risso, 1810) in the southeastern coast of the Caspian Sea

Big-scale sand smelt is one of the fishes with high ecological value, which consume by fishes such as sturgeon in the Caspian Sea. In this study, 191 samples of Big-scale sand smelt from southeast coast of the Caspian Sea were collected seasonally from December 2013 to September 2014. In the present study, food items and the relative index of gastrointestinal (RLG), stomach emptiness index (VI) and feeding intensity (IF) were determined. The fork length, weight and age (mean ±SD) were 7.70 ± 1.09 cm, 3.64 ± 1.49 g and 2.00 ± 0.81 year, respectively. This fish with a relative gastrointestinal tract length of 0.46 ± 0.06 (mean ± Standard Deviation) can be considered as a carnivorous fish. The average of empty stomach was 45% showing big-scale sand smelt is a relatively voracious feeder. The average intensity of feeding (mean± Standard Deviation) 535±221.21, as a moderate level for this fish in the region. Gammarus (benthos) and Daphnia (zooplankton) were the favored food for this fish. This study also showed opportunistic hunting activities of this fish

Interior Point Decoding for Linear Vector Channels

In this paper, a novel decoding algorithm for low-density parity-check (LDPC) codes based on convex optimization is presented. The decoding algorithm, called interior point decoding, is designed for linear vector channels. The linear vector channels include many practically important channels such as inter symbol interference channels and partial response channels. It is shown that the maximum likelihood decoding (MLD) rule for a linear vector channel can be relaxed to a convex optimization problem, which is called a relaxed MLD problem. The proposed decoding algorithm is based on a numerical optimization technique so called interior point method with barrier function. Approximate variations of the gradient descent and the Newton methods are used to solve the convex optimization problem. In a decoding process of the proposed algorithm, a search point always lies in the fundamental polytope defined based on a low-density parity-check matrix. Compared with a convectional joint message passing decoder, the proposed decoding algorithm achieves better BER performance with less complexity in the case of partial response channels in many cases.Comment: 18 pages, 17 figures, The paper has been submitted to IEEE Transaction on Information Theor

Evaluation of biological characteristics such as age, sexuality and growth parameters of fish roach (Rutilus rutilus caspicus) in the southeastern coasts of the Caspian Sea (Sari and Turkmen of port)

Purpose of this study was to evaluate the biological parameters of growth and some roach (Rutilus rutilus caspicus) on the southern coast of the Caspian Sea. Therefore, 160 pieces of fish taken from two the regions and some biological characteristics such as age, sexuality and growth, given the importance and development of population and time were studied. The mean (±Standard Deviation) age, body weight and fork length fish roach respectively in Sari and Turkmen of port 2.8±0.68 and 2.4±0.97 years, 18.56±2.12 and 16.5±2.62 cm, 117.67±48.82 and 76.73±36.31 gr. There is a significant correlation between fork length, weight and age of fish (P<0.001). The sex ratio of male to female fish roach in Sari 1:1.5 and Turkmen of port 1.7: 1, which respectively, differences significant are statistically (Sari: t test=15.39, P<0.001) (Turkmen port: t-test= 18.25, P <0.001). Index GSI (Gonad Somatic Index) in Sari fish roach over the fish roach of Turkmen of port and season gonad growth in both areas was appropriate. The mean condition factor (CF) in Sari and Turkmen of port fish roach showing respectively 1.24±0.14 and 1.12±0.09. Also, the length and weight relationship, positive growth pattern in both locations is displayed. All these factors indicate different status, age, sexuality and growth of the fish is investigated in the two areas

Characterizing Deformation of Buildings from Videos

We have started to explore the feasibility of extracting useful data on the deformation of buildings and structures based on optical videos, (Taghavi Larigani & Heaton). In the beginning, we look at the characterizations and limitations of the hardware, which is composed of a high-quality digital camera, combined with its optical imaging system capturing a video-footage of the structure under test, and then introduce a straightforward targets-tracking algorithm that produces the time-series displacements of targets that we select on the video. We performed preliminary measurements consisting of testing our targets-tracking algorithm using high definition format videos displaying the structures that we wanted to test. The measurements pertain to a 1) finite-element software-generated video of JPL/NASA principal building, 2) YouTube-video of a seismic dynamic test of a building, 3) YouTube-video of the Millennium London Bridge “Wobbly Bridge”, 4) YouTube-video of a United Boeing 777, 4) YouTube-video of NASA space shuttle rockets during launch. So far, our tests are encouraging. If our approach proves viable, it can be transformative for the field of earthquake engineering and structural health monitoring. Hence, we consider the prospect of using our technique for surveying buildings and other civil structures in high seismic risk urban agglomerations. In parallel, the same technique could be applied for 1) real-time structural health monitoring of civil structures, 2) nuclear plants, 3) oil and gas infrastructures, 4) rail & road networks, 5) aircraft, 6) spacecraft, 7) etc., by simply analyzing the structure-facing camera recorded data

Facilitating and inhibiting factors related to treatment adherence in women with polycystic ovary syndrome: a qualitative study

Background: Adherence issues in PCOS patients have not been examined thoroughly. Patients report prolonged periods of treatment and side effects of drug as the most common reason for withdrawal from treatment. To improve the effective management of PCOS patients, it is fundamental to understand facilitating and inhibiting factors to treatment adherence. Objective: to explore facilitating /inhibiting factors related to treatment adherence among PCOS patients. Material and Methods: This was a qualitative study with a purposive sample of women with confirmed diagnosis of PCOS. The data were collected via 20 in-depth semi-structured interviews with women aged between 21 to 34. A qualitative content analysis was used to analyze the data. Results: Five themes were identified which described different types of facilitating /inhibiting factors to treatment adherence. Inhibiting factors included financial issues, patient-related, disease-related, health care provider-related factors; social factors were found to be both facilitating and inhibiting. Conclusion: The findings suggest that successful adherence to PCOS treatment is highly dependent on patients recognizing and adapting to financial, social, and health care related inhibiting factors. It is also crucial for clinicians and policy makers to recognize these key inhibiting factors in order to improve treatment outcomes Keywords: polycystic ovarian syndrome, adherence, qualitative researc

Short communication: Study on heavy metals (Chromium, Cadmium, Cobalt and Lead) concentration in three pelagic species of kilka (Genus Clupeonella) in the southern Caspian Sea

Environmental pollution by heavy metals has been a matter of growing concern over the last decades. Heavy metals are toxic and tend to accumulate in living organisms. In many studies, fish has been used as a sampling item to monitor the quality of ecosystems because of two reasons: 1- Fish bio-concentrate and integrate contaminant load both in time and space leading to more representative results compared to water samples, and 2- Fish represent the bio-available fraction of environmental contaminants, unlike water and sediment samples. On the other hand, humans consume fish species which makes attention to these fauna even more important. Levels of some metals in the water running in Volga River, towards the Caspian Sea, and elevated concentrations of some trace elements have been reported in sediment. Also, various pollutants have accumulated in the Caspian Sea due to effluents from coastal catchments and leakage from offshore oil production and land-based sources. ... The objective of the present study was to investigate the concentrations of chromium (Cr), cadmium (Cd), cobalt (Co) and lead (Pb) in fish muscle in the most commercially important fish species of kilka (common kilka, C. cultriventris, anchovy C. engrauliformis and bigeye kilka C. grimmi) in the Caspian Sea

The Nehari manifold approach for p(x)p(x)-Laplacian problem with Neumann boundary condition

In this paper, we consider the system \begin{eqnarray*} \left\{\begin{array}{ll} -\Delta_{p(x)} u + |u|^{p(x)-2}u = \lambda a(x)|u|^{r_1(x)-2}u + \frac{\alpha(x)}{\alpha(x) + \beta(x)} c(x)|u|^{\alpha(x)-2}u|v|^{\beta(x)} &~\textrm{in}~\Omega\\ -\Delta_{q(x)} v+|v|^{q(x)-2}v = \mu b(x)|v|^{r_2(x)-2}v + \frac{\beta(x)}{\alpha(x) + \beta(x)} c(x)|v|^{\beta(x)-2}v|u|^{\alpha(x)} & ~\textrm{in}~\Omega\\ \frac{\partial u}{\partial \gamma} = \frac{\partial v}{\partial \gamma}= 0 & \textrm{on}~ \partial \Omega \end{array}\right. \end{eqnarray*} where $\Omega \subset R^N$ is a bounded domain with smooth boundary and $\lambda, \mu > 0,~\gamma$ is the outer unit normal to $\partial\Omega$. Under suitable assumptions, we prove the existence of positive solutions by using the Nehari manifold and some variational techniques