An event service supporting autonomic management of ubiquitous systems for e-health

An event system suitable for very simple devices corresponding to a body area network for monitoring patients is presented. Event systems can be used both for self-management of the components as well as indicating alarms relating to patient health state. Traditional event systems emphasise scalability and complex event dissemination for internet based systems, whereas we are considering ubiquitous systems with wireless communication and mobile nodes which may join or leave the system over time intervals of minutes. Issues such as persistent delivery are also important. We describe the design, prototype implementation, and performance characteristics of an event system architecture targeted at this application domain

Forward displacements of fading objects in motion: the role of transient signals in perceiving position

Visual motion causes mislocalisation phenomena in a variety of experimental paradigms. For many displays objects are perceived as displaced 'forward' in the direction of motion. However, in some cases involving the abrupt stopping or reversal of motion the forward displacements are not observed. We propose that the transient neural signals at the offset of a moving object play a crucial role in accurate localisation. In the present study, we eliminated the transient signals at motion offset by gradually reducing the luminance of the moving object. Our results show that the 'disappearance threshold' for a moving object is lower than the detection threshold for the same object without a motion history. In units of time this manipulation led to a forward displacement of the disappearance point by 175ms. We propose an explanation of our results in terms of two processes: Forward displacements are caused by internal models predicting positions of moving objects. The usually observed correct localisation of stopping positions, however, is based on transient inputs that retroactively attenuate errors that internal models might otherwise cause. Both processes are geared to reducing localisation errors for moving objects

Development and evaluation of a fault-tolerant multiprocessor (FTMP) computer. Volume 4: FTMP executive summary

The FTMP architecture is a high reliability computer concept modeled after a homogeneous multiprocessor architecture. Elements of the FTMP are operated in tight synchronism with one another and hardware fault-detection and fault-masking is provided which is transparent to the software. Operating system design and user software design is thus greatly simplified. Performance of the FTMP is also comparable to that of a simplex equivalent due to the efficiency of fault handling hardware. The FTMP project constructed an engineering module of the FTMP, programmed the machine and extensively tested the architecture through fault injection and other stress testing. This testing confirmed the soundness of the FTMP concepts

Study of fault-tolerant software technology

Presented is an overview of the current state of the art of fault-tolerant software and an analysis of quantitative techniques and models developed to assess its impact. It examines research efforts as well as experience gained from commercial application of these techniques. The paper also addresses the computer architecture and design implications on hardware, operating systems and programming languages (including Ada) of using fault-tolerant software in real-time aerospace applications. It concludes that fault-tolerant software has progressed beyond the pure research state. The paper also finds that, although not perfectly matched, newer architectural and language capabilities provide many of the notations and functions needed to effectively and efficiently implement software fault-tolerance

Scalable Crop Yield Prediction with Sentinel-2 Time Series and Temporal Convolutional Network

One of the precepts of food security is the proper functioning of the global food markets. This calls for open and timely intelligence on crop production on an agroclimatically meaningful territorial scale. We propose an operationally suitable method for large-scale in-season crop yield estimations from a satellite image time series (SITS) for statistical production. As an object-based method, it is spatially scalable from parcel to regional scale, making it useful for prediction tasks in which the reference data are available only at a coarser level, such as counties. We show that deep learning-based temporal convolutional network (TCN) outperforms the classical machine learning method random forests and produces more accurate results overall than published national crop forecasts. Our novel contribution is to show that mean-aggregated regional predictions with histogram-based features calculated from farm-level observations perform better than other tested approaches. In addition, TCN is robust to the presence of cloudy pixels, suggesting TCN can learn cloud masking from the data. The temporal compositing of information do not improve prediction performance. This indicates that with end-to-end learning less preprocessing in SITS tasks seems viable

Creation of public use files: lessons learned from the comparative effectiveness research public use files data pilot project

In this paper we describe lessons learned from the creation of Basic Stand Alone (BSA) Public Use Files (PUFs) for the Comparative Effectiveness Research Public Use Files Data Pilot Project (CER-PUF). CER-PUF is aimed at increasing access to the Centers for Medicare and Medicaid Services (CMS) Medicare claims datasets through PUFs that: do not require user fees and data use agreements, have been de-identified to assure the confidentiality of the beneficiaries and providers, and still provide substantial analytic utility to researchers. For this paper we define PUFs as datasets characterized by free and unrestricted access to any user. We derive lessons learned from five major project activities: (i) a review of the statistical and computer science literature on best practices in PUF creation, (ii) interviews with comparative effectiveness researchers to assess their data needs, (iii) case studies of PUF initiatives in the United States, (iv) interviews with stakeholders to identify the most salient issues regarding making microdata publicly available, and (v) the actual process of creating the Medicare claims data BSA PUFs

Forward suppression in the auditory cortex is frequency-specific

We investigated how physiologically observed forward suppression interacts with stimulus frequency in neuronal responses in the guinea pig auditory cortex. The temporal order and frequency proximity of sounds influence both their perception and neuronal responses. Psychophysically, preceding sounds (conditioners) can make successive sounds (probes) harder to hear. These effects are larger when the two sounds are spectrally similar. Physiological forward suppression is usually maximal for conditioner tones near to a unit's characteristic frequency (CF), the frequency to which a neuron is most sensitive. However, in most physiological studies, the frequency of the probe tone and CF are identical, so the role of unit CF and probe frequency cannot be distinguished. Here, we systemically varied the frequency of the probe tone, and found that the tuning of suppression was often more closely related to the frequency of the probe tone than to the unit's CF, i.e. suppressed tuning was specific to probe frequency. This relationship was maintained for all measured gaps between the conditioner and the probe tones. However, when the probe frequency and CF were similar, CF tended to determine suppressed tuning. In addition, the bandwidth of suppression was slightly wider for off-CF probes. Changes in tuning were also reflected in the firing rate in response to probe tones, which was maximally reduced when probe and conditioner tones were matched in frequency. These data are consistent with the idea that cortical neurons receive convergent inputs with a wide range of tuning properties that can adapt independently

A tour of the worm

technical reportOn the evening of November 2, 1988, a self-replicating program was released upon the Internet 1. This program (a worm) invaded VAX and Sun-3 computers running versions of Berkeley UNIX, and used their sources to attack still more computers2. Within the space of hours this program had spread aacross the U.S., infecting hundreds or thousands of computers and making many of them unusable due to the burden of its activity. This paper provides a chronology for the outbreak and presents a detailed description of the internals of the worm, based on a C version produced by decompiling

Subjective Reactions to Noise in Open-Plan Offices and the Effects of Noise on Cognitive Performance - Problems and Solutions

This thesis examines the effects of noise on cognitive performance and subjective reactions in open-plan offices. Earlier research suggests that the acoustic distraction largely results from background speech that is irrelevant to the listener. Combining methods from psychology and room acoustic research, this thesis investigates speech intelligibility as a predictor of the negative effects of background speech and examines some design-related solutions to decreasing these problems. Speech intelligibility is described with the Speech Transmission Index (STI) and the distraction distance which is a room acoustic parameter based on the STI. Evidence from three laboratory experiments and two field studies is presented. The results show that the general perception of both disturbing noise (Study IV) and office distractions (Study V) is strongly correlated with disturbing background speech in open-plan offices. An increase in office distractions mediates negative changes in environmental satisfaction, perceived collaboration and stress symptoms following a move to a modern open-plan office (Study V). The laboratory studies (I, II and III) show that speech intelligibility predicts particularly subjective perceptions of acoustic disturbance but also performance in verbal short-term memory and working memory tasks. The observed performance results are compatible with the STI-performance model proposed by Hongisto (2005). More complex tasks with higher requirements on semantic processing were not affected (Studies I to III). In terms of the investigated solutions, the findings support the use of masking sound in increasing satisfaction with the acoustic environment (Studies I to IV). Filtered pink noise and spring water sound are effective and pleasant masking sounds whereas music cannot be recommended for general use (Study II). Together, Studies III and IV show that perceived noise disturbance can be decreased in open-plan offices by holistic room acoustic design. However, its benefits are limited at short distances between nearby workstations (Study III). Distraction distance predicts perceived noise disturbance in open-plan offices (Study IV), which supports its use in the evaluation and design of office acoustics. The provision of additional quiet workspaces is a complementary way of decreasing the negative effects of office distractions in modern open-plan offices (Study V). Limitations of this work and suggestions for future research are discussed.Subjektiiviset reaktiot avotoimistojen meluun ja melun vaikutukset kognitiiviseen suoriutumiseen. Ongelmia ja ratkaisuja Tämä väitöskirjatutkimus käsittelee melun vaikutuksia kognitiiviseen suoriutumiseen ja subjektiivisiin reaktioihin avotoimistoissa. Aiempien tutkimusten mukaan koetut akustiset ongelmat liittyvät suurelta osin sellaisiin puheääniin, jotka ovat kuulijan kannalta hyödyttömiä. Tässä tutkimuksessa selvitetään psykologisia ja huoneakustisia tutkimusmenetelmiä yhdistäen puheenerotettavuuden merkitystä puheen negatiivisten vaikutusten selittäjänä sekä tutkitaan toimistosuunnittelun keinoja ongelmien vähentämiseksi. Puheenerotettavuutta kuvataan puheensiirtoindeksillä ja häiritsevyyssäteellä, joka on puheensiirtoindeksiin perustuva huoneakustinen mittaluku. Tutkimus sisältää kolme kokeellista laboratoriotutkimusta ja kaksi kenttätutkimusta. Tulosten perusteella sekä häiritsevä melu (Tutkimus IV) että kokemus työympäristön häiriötekijöistä (Tutkimus V) korreloivat vahvasti puheäänten häiritsevyyden kanssa. Häiriötekijöiden lisääntyminen toimii välittävänä tekijänä suhteessa negatiivisiin muutoksiin ympäristötyytyväisyydessä, yhteistyön kokemisessa sekä stressioireissa avotoimistoon muuton jälkeen (Tutkimus V). Laboratoriotutkimukset (I, II ja III) osoittavat, että puheenerotettavuus ennustaa erityisesti akustisten olosuhteiden subjektiivista häiritsevyyttä, mutta myös suoriutumista verbaalisissa lyhytkestoisen muistin ja työmuistin tehtävissä. Kognitiivista suoriutumista koskevat tulokset ovat yhdenmukaisia Hongiston (2005) esittämän, puheensiirtoindeksin ja suoriutumisen suhdetta kuvaavan mallin kanssa. Kompleksisemmissa, enemmän semanttista prosessointia sisältävissä tehtävissä ei havaittu puheäänten vaikutuksia kognitiiviseen suoriutumiseen (Tutkimukset I-III). Tutkittujen ratkaisukeinojen osalta tulokset tukevat peiteäänen käyttöä akustisen tyytyväisyyden parantamisessa (Tutkimukset I-IV). Suodatettu kohina ja puronsolina ovat tehokkaita ja miellyttäviä peiteääniä, kun taas musiikkia ei voida suositella yleiseen käyttöön (Tutkimus II). Tutkimukset III ja IV osoittavat, että akustisia ongelmia voidaan vähentää kokonaisvaltaisella huoneakustisella suunnittelulla. Sen hyödyt ovat kuitenkin rajallisia lyhyillä etäisyyksillä lähityöpisteiden välillä (Tutkimus III). Häiritsevyyssäde selittää koettua melun häiritsevyyttä avotoimistoissa (Tutkimus IV), mikä tukee sen käyttöä toimistojen akustisten olosuhteiden arvioinnissa ja suunnittelussa. Työympäristön häiriötekijöiden negatiivisia vaikutuksia voidaan lisäksi vähentää rakentamalla avotoimistoihin vaihtoehtoisia hiljaisia työtiloja (Tutkimus V). Väitöskirjan lopussa tarkastellaan tutkimuksen rajoituksia sekä jatkotutkimustarpeita.Siirretty Doriast

What do contrast threshold equivalent noise studies actually measure? Noise vs. nonlinearity in different masking paradigms

The internal noise present in a linear system can be quantified by the equivalent noise method. By measuring the effect that applying external noise to the system’s input has on its output one can estimate the variance of this internal noise. By applying this simple “linear amplifier” model to the human visual system, one can entirely explain an observer’s detection performance by a combination of the internal noise variance and their efficiency relative to an ideal observer. Studies using this method rely on two crucial factors: firstly that the external noise in their stimuli behaves like the visual system’s internal noise in the dimension of interest, and secondly that the assumptions underlying their model are correct (e.g. linearity). Here we explore the effects of these two factors while applying the equivalent noise method to investigate the contrast sensitivity function (CSF). We compare the results at 0.5 and 6 c/deg from the equivalent noise method against those we would expect based on pedestal masking data collected from the same observers. We find that the loss of sensitivity with increasing spatial frequency results from changes in the saturation constant of the gain control nonlinearity, and that this only masquerades as a change in internal noise under the equivalent noise method. Part of the effect we find can be attributed to the optical transfer function of the eye. The remainder can be explained by either changes in effective input gain, divisive suppression, or a combination of the two. Given these effects the efficiency of our observers approaches the ideal level. We show the importance of considering these factors in equivalent noise studies