1,578 research outputs found

    Robust vector quantization for noisy channels

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    The paper briefly discusses techniques for making vector quantizers more tolerant to tranmsission errors. Two algorithms are presented for obtaining an efficient binary word assignment to the vector quantizer codewords without increasing the transmission rate. It is shown that about 4.5 dB gain over random assignment can be achieved with these algorithms. It is also proposed to reduce the effects of error propagation in vector-predictive quantizers by appropriately constraining the response of the predictive loop. The constrained system is shown to have about 4 dB of SNR gain over an unconstrained system in a noisy channel, with a small loss of clean-channel performance

    Microalbuminuria, peripheral artery disease, and cognitive function

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    Kidney disease may be linked to a decline in cognitive activity. We examined the association of microalbuminuria and cognitive function in a general population of older adults in the United States drawn from the National Health and Nutrition Examination Survey of 1999–2002. Cognitive function was measured by digit symbol substitution in 2386 participants 60 years of age and older of whom 448 had microalbuminuria. Covariates included age, gender, race/ethnicity, education, smoking, diabetes, and hypertension. Among participants with peripheral artery disease, those with microalbuminuria had a significantly lower cognitive function score compared to those with a normal albumin-to-creatinine ratio. The association between microalbuminuria and cognitive function was weak in those without peripheral artery disease. But in those with peripheral artery disease, the odds of microalbuminuria associated with cognitive function in the lowest and middle tertiles was 6.5 and 3.5, respectively

    Variability Abstraction and Refinement for Game-Based Lifted Model Checking of Full CTL

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    One of the most promising approaches to fighting the configuration space explosion problem in lifted model checking are variability abstractions. In this work, we define a novel game-based approach for variability-specific abstraction and refinement for lifted model checking of the full CTL, interpreted over 3-valued semantics. We propose a direct algorithm for solving a 3-valued (abstract) lifted model checking game. In case the result of model checking an abstract variability model is indefinite, we suggest a new notion of refinement, which eliminates indefinite results. This provides an iterative incremental variability-specific abstraction and refinement framework, where refinement is applied only where indefinite results exist and definite results from previous iterations are reused. The practicality of this approach is demonstrated on several variability models

    A Game of Attribute Decomposition for Software Architecture Design

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    Attribute-driven software architecture design aims to provide decision support by taking into account the quality attributes of softwares. A central question in this process is: What architecture design best fulfills the desirable software requirements? To answer this question, a system designer needs to make tradeoffs among several potentially conflicting quality attributes. Such decisions are normally ad-hoc and rely heavily on experiences. We propose a mathematical approach to tackle this problem. Game theory naturally provides the basic language: Players represent requirements, and strategies involve setting up coalitions among the players. In this way we propose a novel model, called decomposition game, for attribute-driven design. We present its solution concept based on the notion of cohesion and expansion-freedom and prove that a solution always exists. We then investigate the computational complexity of obtaining a solution. The game model and the algorithms may serve as a general framework for providing useful guidance for software architecture design. We present our results through running examples and a case study on a real-life software project.Comment: 23 pages, 5 figures, a shorter version to appear at 12th International Colloquium on Theoretical Aspects of Computing (ICTAC 2015

    Impact evaluation of different cash-based intervention modalities on child and maternal nutritional status in Sindh Province, Pakistan, at 6 mo and at 1 y: A cluster randomised controlled trial

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    BACKGROUND: Cash-based interventions (CBIs), offer an interesting opportunity to prevent increases in wasting in humanitarian aid settings. However, questions remain as to the impact of CBIs on nutritional status and, therefore, how to incorporate them into emergency programmes to maximise their success in terms of improved nutritional outcomes. This study evaluated the effects of three different CBI modalities on nutritional outcomes in children under 5 y of age at 6 mo and at 1 y. METHODS AND FINDINGS: We conducted a four-arm parallel longitudinal cluster randomised controlled trial in 114 villages in Dadu District, Pakistan. The study included poor and very poor households (n = 2,496) with one or more children aged 6–48 mo (n = 3,584) at baseline. All four arms had equal access to an Action Against Hunger–supported programme. The three intervention arms were as follows: standard cash (SC), a cash transfer of 1,500 Pakistani rupees (PKR) (approximately US14;1PKR=US14; 1 PKR = US0.009543); double cash (DC), a cash transfer of 3,000 PKR; or a fresh food voucher (FFV) of 1,500 PKR; the cash or voucher amount was given every month over six consecutive months. The control group (CG) received no specific cash-related interventions. The median total household income for the study sample was 8,075 PKR (approximately US$77) at baseline. We hypothesized that, compared to the CG in each case, FFVs would be more effective than SC, and that DC would be more effective than SC—both at 6 mo and at 1 y—for reducing the risk of child wasting. Primary outcomes of interest were prevalence of being wasted (weight-for-height z-score [WHZ] < −2) and mean WHZ at 6 mo and at 1 y. The odds of a child being wasted were significantly lower in the DC arm after 6 mo (odds ratio [OR] = 0.52; 95% CI 0.29, 0.92; p = 0.02) compared to the CG. Mean WHZ significantly improved in both the FFV and DC arms at 6 mo (FFV: z-score = 0.16; 95% CI 0.05, 0.26; p = 0.004; DC: z-score = 0.11; 95% CI 0.00, 0.21; p = 0.05) compared to the CG. Significant differences on the primary outcome were seen only at 6 mo. All three intervention groups showed similar significantly lower odds of being stunted (height-for-age z-score [HAZ] < −2) at 6 mo (DC: OR = 0.39; 95% CI 0.24, 0.64; p < 0.001; FFV: OR = 0.41; 95% CI 0.25, 0.67; p < 0.001; SC: OR = 0.36; 95% CI 0.22, 0.59; p < 0.001) and at 1 y (DC: OR = 0.53; 95% CI 0.35, 0.82; p = 0.004; FFV: OR = 0.48; 95% CI 0.31, 0.73; p = 0.001; SC: OR = 0.54; 95% CI 0.36, 0.81; p = 0.003) compared to the CG. Significant improvements in height-for-age outcomes were also seen for severe stunting (HAZ < −3) and mean HAZ. An unintended outcome was observed in the FFV arm: a negative intervention effect on mean haemoglobin (Hb) status (−2.6 g/l; 95% CI −4.5, −0.8; p = 0.005). Limitations of this study included the inability to mask participants or data collectors to the different interventions, the potentially restrictive nature of the FFVs, not being able to measure a threshold effect for the two different cash amounts or compare the different quantities of food consumed, and data collection challenges given the difficult environment in which this study was set. CONCLUSIONS: In this setting, the amount of cash given was important. The larger cash transfer had the greatest effect on wasting, but only at 6 mo. Impacts at both 6 mo and at 1 y were seen for height-based growth variables regardless of the intervention modality, indicating a trend toward nutrition resilience. Purchasing restrictions applied to food-based voucher transfers could have unintended effects, and their use needs to be carefully planned to avoid this

    New Directions in Subband Coding

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    Two very different subband coders are described. The first is a modified dynamic bit-allocation-subband coder (D-SBC) designed for variable rate coding situations and easily adaptable to noisy channel environments. It can operate at rates as low as 12 kb/s and still give good quality speech. The second coder is a 16-kb/s waveform coder, based on a combination of subband coding and vector quantization (VQ-SBC). The key feature of this coder is its short coding delay, which makes it suitable for real-time communication networks. The speech quality of both coders has been enhanced by adaptive postfiltering. The coders have been implemented on a single AT&T DSP32 signal processo

    Assessing the relationship between sleep duration and the prevalence of chronic kidney disease among Veterans in the United States. A 2022 BRFSS Cross-Sectional Study

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    Abstract Background: Chronic Kidney Disease (CKD) ranks among the leading causes of death in the United States (US). As of 2023, there are approximately 36 million people with CKD in the United States. About 1 in 6 veterans suffer from CKD, an increase of almost 35 percent over its prevalence in the general population. The treatment of veterans with chronic kidney disease (CKD) incurred nearly $20 billion in costs ten years ago for the Department of Veterans Affairs (VA) and this expenditure is expected to have significantly increased, considering the VA\u27s projection of over 29,500 new CKD diagnoses among veterans annually. Adequate sleep is crucial for maintaining normal bodily functions. Prior studies on sleep dynamics among former United States service members reveal that a significant portion consistently report insufficient daily sleep below 7 hours. This study will aim to investigate whether length of sleep is related to the likelihood of having chronic kidney disease specifically among veterans in the United States. Methods: For this cross-sectional study, we utilized secondary data from the Behavioral Risk Factor Surveillance System (BRFSS) 2022 data set. This study included all veterans with a sample size of 53211. This population represents 12% of the general population that responded to the survey. Measures include the outcome variable which is veterans with/without chronic kidney disease and a major independent variable sleep duration. Sleep duration was recategorized into \u3c5hours, 6-10hours, \u3e10hours. Covariates include gender, age, race, residence, insurance, alcohol consumption, diabetes comorbidity, and stroke comorbidity. A descriptive bivariate and multivariate logistic regressions were conducted using the Statistical Analysis System (SAS). Results: The prevalence of chronic kidney disease among veterans in the United States is 6.29%. Veterans with sleep duration of 6-10 hours had 17.5% lower odds of chronic kidney disease than veterans who sleep for 1-5 hours (AOR= 0.825, CI= 0.821,0.830, P=\u3c0.0001). Veterans who sleep for more than 10 hours had 68.2% higher odds of having CKD (AOR=1.682, CI= 1.662,1.702, P=\u3c0.0001). Veterans who consume alcohol had 7.8% lower odds of having chronic kidney disease as compared to individuals who do not consume alcohol (AOR= 0.922 CI =0.918,0.927 p=\u3c0.0001). Male veterans had 24.7% lower odds of having chronic kidney disease as compared to female veterans. Additionally, veterans diagnosed with diabetes, stroke, and coronary artery disease had 2.447, 2.103, and 2.838, respectively, higher odds of developing chronic kidney disease. (AOR=2.447, CI= 2.435,2.459 p=\u3c0.0001). Conclusion: This research provides evidence of a greater incidence of CKD among veterans with short sleep duration(1-5 hours) and very long sleep duration (\u3e 10 hours), forming a ‘U’ curve relationship. Sleep hygiene education and sleep optimization programs could improve sleep and boost overall kidney health among veterans
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