An improved algorithm for evaluating trellis phase codes

A method is described for evaluating the minimum distance parameters of trellis phase codes, including CPFSK, partial response FM, and more importantly, coded CPM (continuous phase modulation) schemes. The algorithm provides dramatically faster execution times and lesser memory requirements than previous algorithms. Results of sample calculations and timing comparisons are included

Efficient use of bit planes in the generation of motion stimuli

The production of animated motion sequences on computer-controlled display systems presents a technical problem because large images cannot be transferred from disk storage to image memory at conventional frame rates. A technique is described in which a single base image can be used to generate a broad class of motion stimuli without the need for such memory transfers. This technique was applied to the generation of drifting sine-wave gratings (and by extension, sine wave plaids). For each drifting grating, sine and cosine spatial phase components are first reduced to 1 bit/pixel using a digital halftoning technique. The resulting pairs of 1-bit images are then loaded into pairs of bit planes of the display memory. To animate the patterns, the display hardware's color lookup table is modified on a frame-by-frame basis; for each frame the lookup table is set to display a weighted sum of the spatial sine and cosine phase components. Because the contrasts and temporal frequencies of the various components are mutually independent in each frame, the sine and cosine components can be counterphase modulated in temporal quadrature, yielding a single drifting grating. Using additional bit planes, multiple drifting gratings can be combined to form sine-wave plaid patterns. A large number of resultant plaid motions can be produced from a single image file because the temporal frequencies of all the components can be varied independently. For a graphics device having 8 bits/pixel, up to four drifting gratings may be combined, each having independently variable contrast and speed

Effect of contrast on the perception of direction of a moving pattern

A series of experiments examining the effect of contrast on the perception of moving plaids was performed to test the hypothesis that the human visual system determines the direction of a moving plaid in a two-staged process: decomposition into component motion followed by application of the intersection-of-contraints rule. Although there is recent evidence that the first tenet of the hypothesis is correct, i.e., that plaid motion is initially decomposed into the motion of the individual grating components, the nature of the second-stage combination rule has not yet been established. It was found that when the gratings within the plaid are of different contrast the preceived direction is not predicted by the intersection-of-constraints rule. There is a strong (up to 20 deg) bias in the direction of the higher-constrast grating. A revised model, which incorporates a contrast-dependent weighting of perceived grating speed as observed for one-dimensional patterns, can quantitatively predict most of the results. The results are then discussed in the context of various models of human visual motion processing and of physiological responses of neurons in the primate visual system

Gravity Duals of Lifshitz-like Fixed Points

We find candidate macroscopic gravity duals for scale-invariant but non-Lorentz invariant fixed points, which do not have particle number as a conserved quantity. We compute two-point correlation functions which exhibit novel behavior relative to their AdS counterparts, and find holographic renormalization group flows to conformal field theories. Our theories are characterized by a dynamical critical exponent $z$, which governs the anisotropy between spatial and temporal scaling $t \to \lambda^z t$, $x \to \lambda x$; we focus on the case with $z=2$. Such theories describe multicritical points in certain magnetic materials and liquid crystals, and have been shown to arise at quantum critical points in toy models of the cuprate superconductors. This work can be considered a small step towards making useful dual descriptions of such critical points.Comment: 17 pages, harvmac; v2 comments about behavior of metric near r=0 added (thanks to S. Hartnoll and G. Horowitz

Blockchain for sustainability: a systematic literature review for policy impact

Blockchain technology has been proposed to achieve sustainable development through various solutions, such as carbon credit trading, energy systems and supply chain management. While existing literature has not covered this topic in a structured fashion, this paper provides insights to policymakers on how blockchain can deliver sustainable development. This study conducted a systematic literature review on the role of blockchain technologies in assisting policymakers in achieving ESG and environmental sustainability goals. The paper performs a detailed PRISMA SLR analysis of 10,188 technical and policy papers sourced from Scopus and IEEE databases to ensure high-quality inputs and breadth of coverage across relevant sources. In addition, the study reviews the relevant regulatory environment related to ESG, including SDGs, IPCC, COP 27, ESMA, ISSB, SEC, GRI, TCFD, ESRS, IFRS S1 and S2 and CRSD. Most papers do not outline a structured approach to applying blockchain in the emerging regulatory environment. Our paper outlines recommendations to policymakers wishing to ensure that the blockchain research community and solutions proposed are usefully directed to enable the world to achieve its net zero goals

Application and Effectiveness of Telehealth to Support Severe Mental Illness Management: Systematic Review

Background: It is important that people with SMI receive early interventions to prevent mental health deterioration or relapse. Telecommunications and other technologies are increasingly used to assist healthcare delivery (‘telehealth’) , providing service users with immediate real-time information to improve the management of chronic health conditions. Telehealth has been found to be successful in improving management and symptoms across a number of health conditions, whilst also being acceptable to users. Initial findings suggest technology could improve quality of life in people with SMI. Objectives: This systematic review aimed to identify the variety of uses and efficacy of teleheal th technology for SMI. Methods: We systematically searched electronic databases from inception to March 2016 (MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, AMED, He alth Techno logy Assessment, CINAHL plus and NHS EED ) for randomised controlled trials (RCTs) evaluating telehealth for adults with SMI , published in English. Additional literature was identified by searching reference lists of key articles. The articles meeting the inclusion criteria were systematically reviewed and assessed for quality and risk of bias. Results: The search identified 31 eligible articles, describing 29 trials. The included studies evaluated the use of computers to deliver cognitive rehabilitation (1 5 trials), patient education (3 trials), online self- management interventions (2 trials), and to support consultations (1 trial). Virtual reality (VR) was used to simulate work and social sit uations (2 trials ) and to deliver cognitive training (1 trial). Telephones were used to prompt medication use (3 trials ) and report SMI symptoms to healthcare teams (1 trial ). Remote sensors were used to monitor medication use (1 trial). Telephone support was found effective for improving medication adherence and reducing symptom severity and inpatient days. Computer assisted cognitive rehabilitation was effective in improving cognitive function. The impact of telehealth on other outcomes was inconsistent. Few studies evaluated the 3 use of remote medication telemonitoring, VR, online self-management and computer -mediated consultations, suggesting these are novel technologies for managing SMI, although all were found effective for improving psycho social and behavioural outcomes. The results of this review should be taken in the context of varied quality in study design, with only five studies demonstrating a low risk of bias. Conclusions : A growing variety of telehealth technologies are used to support SMI. Specific types of technology have been found to be effective for som e outcomes, for example telephone prompts for medication adherence, while other types of telehealth had no benefit over traditional methods and were less acceptable to patients. Few studies found benefits for telehealth on quality of life, except for novel technologies with a limited number of trials. Further research is warranted to establish the full potential benefits of telehealth for improving quality of life in SMI, acceptability from the service user perspective, and cost-effectivenes

Bis(tetraphenylphosphonium) di-μ-iodido-bis[diiodidopalladate(II)].

The title compound, (PPh4)2[Pd2I6], was obtained unintentionally as the product of an attempted synthesis of a tripalladium sandwich complex. The molecular dimensions are unexceptional and the Pd---Pd distance, at 3.8183 (12) A,is much too long for any Pd—Pd interaction. Pd has a typical square-planar coordination geometry and the centrosymmetric anion is essentially planar