971 resultados para Round Robin Database Measurement Archive
Resumo:
Mobile applications are being increasingly deployed on a massive scale in various mobile sensor grid database systems. With limited resources from the mobile devices, how to process the huge number of queries from mobile users with distributed sensor grid databases becomes a critical problem for such mobile systems. While the fundamental semantic cache technique has been investigated for query optimization in sensor grid database systems, the problem is still difficult due to the fact that more realistic multi-dimensional constraints have not been considered in existing methods. To solve the problem, a new semantic cache scheme is presented in this paper for location-dependent data queries in distributed sensor grid database systems. It considers multi-dimensional constraints or factors in a unified cost model architecture, determines the parameters of the cost model in the scheme by using the concept of Nash equilibrium from game theory, and makes semantic cache decisions from the established cost model. The scenarios of three factors of semantic, time and locations are investigated as special cases, which improve existing methods. Experiments are conducted to demonstrate the semantic cache scheme presented in this paper for distributed sensor grid database systems.
Resumo:
We have measured hyperfine structure in the first-excited P state (D lines) of all the naturally occurring alkali atoms. We use high-resolution laser spectroscopy to resolve hyperfine transitions, and measure intervals by locking the frequency shift produced by an acousto-optic modulator to the difference between two transitions. In most cases, the hyperfine coupling constants derived from our measurements improve previous values significantly.
Resumo:
Balance and stability are very important for everybody and especially for sports-person who undergo extreme physical activities. Balance and stability exercises not only have a great impact on the performance of the sportsperson but also play a pivotal role in their rehabilitation. Therefore, it is very essential to have knowledge about a sportsperson’s balance and also to quantify the same. In this work, we propose a system consisting of a wobble board, with a gyro enhanced orientation sensor and a motion display for visual feedback to help the sportsperson improve their stability. The display unit gives in real time the orientation of the wobble board, which can help the sportsperson to apply necessary corrective forces to maintain neutral position. The system is compact and portable. We also quantify balance and stability using power spectral density. The sportsperson is made stand on the wobble board and the angular orientation of the wobble board is recorded for each 0.1 second interval. The signal is analized using discrete Fourier transforms. The power of this signal is related to the stability of the subject. This procedure is used to measure the balance and stability of an elite cricket team. Representative results are shown below: Table 1 represents power comparison of two subjects and Table 2 represents power comparison of left leg and right leg of one subject. This procedure can also be used in clinical practice to monitor improvement in stability dysfunction of sportsperson with injuries or other related problems undergoing rehabilitation.
Resumo:
The 6-item Kessler Psychological Distress Scale (K6; Kessler et al., 2002) is a screener for psychological distress that has robust psychometric properties among adults. Given that a significant proportion of adolescents experience mental illness, there is a need for measures that accurately and reliably screen for mental disorders in this age group. This study examined the psychometric properties of the K6 in a large general population sample of adolescents (N = 4,434; mean age = 13.5 years; 44.6% male). Factor analyses were conducted to examine the dimensionality of the K6 in adolescents and to investigate sex-based measurement invariance. This study also evaluated the K6 as a predictor of scores on the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997). The K6 demonstrated high levels of internal consistency, with the 6 items loading primarily on 1 factor. Consistent with previous research, females reported higher mean levels of psychological distress when compared with males. The identification of sex-based measurement noninvariance in the item thresholds indicated that these mean differences most likely represented reporting bias in the K6 items rather than true differences in the underlying psychological distress construct. The K6 was a fair to good predictor of abnormal scores on the SDQ, but predictive utility was relatively low among males. Future research needs to focus on refining and augmenting the K6 scale to maximize its utility in adolescents. (PsycINFO Database Record (c) 2015 APA, all rights reserved)
Resumo:
Measurable electrical signal is generated when a gas flows over a variety of solids, including doped semiconductors, even at the modest speed of a few meters per second. The underlying mechanism is an interesting interplay of Bernoulli's principle and the Seebeck effect. The electrical signal depends on the square of Mach number (M) and is proportional to the Seebeck coefficient (S) of the solids. Here we present experimental estimate of the response time of the signal rise and fall process, i.e. how fast the semiconductor materials respond to a steady flow as soon as it is set on or off. A theoretical model is also presented to understand the process and the dependence of the response time on the nature and physical dimensions of the semiconductor material used and they are compared with the experimental observations. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Tutkimuksen keskeinen tehtävä on selvittää, mikä on dokumentoinnin merkitys lastensuojelun sosiaalityön tiedonmuodostuksessa ja ammattikäytännöissä. Asiakirjateksteistä koostuvaa tutkimusaineistoa tarkastellaan kolmesta eri suunnasta kysymällä: 1)Miten asiakirjoja kirjoitetaan? 2) Mitä asiakirjoihin kirjoitetaan? 3) Miksi asiakirjoja kirjoitetaan niin kuin kirjoitetaan? Tutkimusaineisto muodostuu lastensuojelun sosiaalityöntekijöiden laatimista asiakastietojärjestelmään tallennetuista muistiinpanoista ja huostaanottopäätöksistä. Tutkimukseen on valittu 20 huostaanotetun eri-ikäisen lapsen ja heidän perheensä asiakirjat yhteensä 1613 asiakirjatulostussivua. Tekstit ajoittuvat vuodesta 1989 vuoteen 2000. Tutkimusmenetelmä on diskurssianalyyttinen ja tukeutuu Fairclough`n (1997)esittämään kolmiulotteiseen malliin, jossa diskurssi määritellään tekstin, käytäntöjen ja sosiokulttuurisen ympäristön suhteeksi. Diskurssianalyysi on näiden rakenteiden ja niiden välisten suhteiden kuvaamista, tulkintaa ja selittämistä. Fairclough’n mallia mukaillen tutkimuksen analyysi koostuu retoriikan ja tematiikan analyyseistä sekä pragmatiikan näkökulman sisältävästä tarkastelusta. Asiakirjatekstien pilkkominen puhujakategorioihin osoitti tekstien olevan moniäänisiä, useiden henkilöiden näkemyksiä ja mielipiteitä sisältäviä tekstipintoja. Retoriikan analyysi näytti, että lastensuojelun sosiaalityön asiakirjat sisältävät paljon dynaamisia kuvauksia työstä. Asiakirjojen kirjoittaminen moniäänisiksi tuo tekstiin uskottavuutta, ja se on myös yksi retorinen vaikuttamiskeino. Tematiikan tarkastelu osoitti,että asiakirjojen sisällölliset teemat (lapsen hoiva, arjen hallinta, yhteistyö ja päihteiden käyttö) ja kokemukselliset teemat (huoli, vastuu, yhteys ja moraali) toistuvat sisäkkäisinä ja päällekkäisinä säikeinä dynaamisesti vaihdellen. Sosiaalityöntekijät kirjaavat teksteihin monia yhtäaikaisia teemoja, joiden avulla rakentavat ammatillista ymmärrystä kyseessä olevasta tilanteesta. Asiakirjojen tutkiminen pragmatiikan suunnasta toi esiin, kirjoittamisen ja lukemisen kontekstiulottuvuudet sekä tiedonmuodostusprosessin. Asiakirjojen laatiminen on osa sosiaalityön käytäntöjä. Se on myös keskeinen alue ammattikunnan yhteisen ammatillisen ymmärryksen luomisessa ja ylläpitämisessä. Muistiinpanot, huostaanottopäätökset ja lakitekstit ovat intertekstuaalisia. Lastensuojelun sosiaalityön asiakirjojen tutkiminen on avannut uusia mahdollisuuksia ymmärtää sosiaalityön dokumentointiprosessia, merkitystä ja roolia sekä tiedonmuodostuksen dynamiikkaa. Tekstien kirjoittaminen, niiden lukeminen, tietojen siirtäminen ja asiakkaan kuuleminen samoin kuin kuulemisen kirjaaminen ovat sosiaalityön dokumentoinnin keskeisiä haasteita. Tutkimus pyrkii avaamaan ymmärrystä asiakirjatekstien monivivahteiseen ja dynaamiseen maailmaan ja siten myös sosiaalityön dokumentoinnin arkeen. Tarkastelut mahdollistavat työn kehittämisen erityisesti sosiaalityön asiakasvaikuttavuuden mittaamisen ja parantamisen suuntaan. Asiakirjoissa ilmenevä tiedonmuodostuksen dynamiikka syntyy kirjoittamiskäytäntöjen, kirjoittamisen ja lukemisen sekä toimintakäytäntöjen yhteisessä alueessa. Avainsanat: sosiaalityö, lastensuojelu, dokumentointi, asiakirja, diskurssianalyysi, tiedonmuodostus.
Resumo:
A new approach for unwrapping phase maps, obtained during the measurement of 3-D surfaces using sinusoidal structured light projection technique, is proposed. "Takeda's method" is used to obtain the wrapped phase map. Proposed method of unwrapping makes use of an additional image of the object captured under the illumination of a specifically designed color-coded pattern. The new approach demonstrates, for the first time, a method of producing reliable unwrapping of objects even with surface discontinuities from a single-phase map. It is shown to be significantly faster and reliable than temporal phase unwrapping procedure that uses a complete exponential sequence. For example, if a measurement with the accuracy obtained by interrogating the object with S fringes in the projected pattern is carried out with both the methods, new method requires only 2 frames as compared to (log(2)S +1) frames required by the later method.
Resumo:
We report on a CDF measurement of the total cross section and rapidity distribution, $d\sigma/dy$, for $q\bar{q}\to \gamma^{*}/Z\to e^{+}e^{-}$ events in the $Z$ boson mass region ($66M_{ee}
Resumo:
We report a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a Pythia prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.
Resumo:
The purpose of this article is to report the experience of design and testing of orifice plate-based flow measuring systems for evaluation of air leakages in components of air conditioning systems. Two of the flow measuring stations were designed with a beta value of 0.405 and 0.418. The third was a dual path unit with orifice plates of beta value 0.613 and 0.525. The flow rates covered with all the four were from 4-94 l/s and the range of Reynolds numbers is from 5600 to 76,000. The coefficients of discharge were evaluated and compared with the Stolz equation. Measured C-d values are generally higher than those obtained from the equation, the deviations being larger in the low Reynolds number region. Further, it is observed that a second-degree polynomial is inadequate to relate the pressure drop and flow rate. The lower Reynolds number limits set by standards appear to be somewhat conservative.
Resumo:
Hall thrusters, such as Stationary Plasma Thruster (SPT), have been widely used on board modern satellites placed in geo-synchronows orbits for reasons such as orbit maintenance, repositioning and attitude control. In order to study the performance of the stationary plasma thruster, the thrust produced by it has been measured, using a thrust balance with strain gauge sensors under vacuum conditions, by activating the thruster. This activation of thruster has been carried out by switching ON and switching OFF of the necessary power supplies and control of other feed system such as the propellant flow in a particular sequence. Hitherto, these operations were done manually in the required sequence. This paper reports the attempt made to automate the sequential operation of the power supplies and the necessary control valves of the feed system using Intel 8051 microcontroller. This automation has made thrust measurements easier and more sophisticated.
Resumo:
We report a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a Pythia prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.
Resumo:
We present measurements of the top quark mass using the \mT2, a variable related to the transverse mass in events with two missing particles. We use the template method applied to t\tbar dilepton events produced in p\pbar collisions at Fermilab's Tevatron and collected by the CDF detector. From a data sample corresponding to an integrated luminosity of 3.4 \invfb, we select 236 t\tbar candidate events. Using the \mT2 distribution, we measure the top quark mass to be M_{Top} = 168.0^{+4.8}_{-4.0} $\pm$ {2.9} GeV/c^{2}. By combining the \mT2 with the reconstructed top mass distributions based on a neutrino weighting method, we measure M_{top}=169.3 $\pm$ 2.7 $\pm$ 3.2 GeV/c^{2}. This is the first application of the \mT2 variable in a mass measurement at a hadron collider.