Above-mentioned Assumption Research Articles

Parameter identifications of synchronous vibration of rotating blades with large amplitude based on blade tip timing

Blade Tip Timing (BTT) is a promising method to measure the vibration of rotating blades by installing probes on the casing. The Zablotsky-Korostelev Single Parameter Technique (SPT) is widely used to identify the vibrational characteristics of blade synchronous responses. This method assumes that the influence of blade’s own vibration on arrival time can be neglected. However, it is reported that vibrations of rotating blades with large amplitudes will cause errors in identifying maximum vibration amplitude because of the above-mentioned assumption. In this paper, we derived a mathematical model of single degree of freedom (SDOF) blade model discarding the assumption of small amplitude related to BTT actual measurement. Compared to traditional SPT, our model takes the influence of blade’s own vibration into consideration. Then, we improved SPT and derived a precise measurement formula. Arrival time of blade to the sensor was revised. Based on this, we conducted a parametrical study on the effects of changes in various factors including excitation force, damping ratio, engine order, and the installation position of the sensor by numerical simulations. Displacements between considering blade’s own vibration and not were compared. Errors in fitted parameters were also analyzed. The numerical simulation results show that large engine order will magnify the error in fitted parameters if traditional SPT was used. Damping ratio and maximum vibration amplitude have relatively large errors in fitting parameters. Furthermore, we designed an experimental bench to verify the mathematical model and the revised measurement formula.

Are customers ready to be smart? designing smart hotel experiences

Purpose – Even if it is often accepted that smart hotels are built on networks of technological devices, there is currently no consensus among researchers as to what level of technology is required to define a smart hotel. Based on the above-mentioned assumption that smart hotels are built on a network of technological devices, this paper aims to understand how smart hotels can be conceptualised based on customer preferences. Methodology/Design/Approach – To achieve this goal, the paper conceptualises smart hotels as a service network in which the customer comes into contact with a variety of technological and traditional touchpoints on site. This conceptualisation allows the researcher to observe customer preferences at different touchpoints and identify the technologies that are central to the development of the customer experience. Findings – The results show that the ideal customer journey includes both traditional and technological touchpoints and that artificial intelligence is of central importance for the development of the smart hotel concept. Originality of the research – The methodological approach taken in this paper enables researchers and practitioners to easily visualise and identify important patterns in the customer journey, facilitating the task of identifying the most relevant touchpoints in complex service networks, such as smart hotels.

Adjustment for Multimorbidity in Estimations of the Burden of Diseases Using Korean NHIS Data.

The current multimorbidity correction method in the Global Burden of Disease studies assumes the independent occurrence of diseases. Those studies use Monte-Carlo simulations to adjust for the presence of multiple disease conditions for all diseases. The present study investigated whether the above-mentioned assumption is reasonable based on the prevalence confirmed from actual data. This study compared multimorbidity-adjusted years of lived with disability (YLD) obtained by Monte-Carlo simulations and multimorbidity-adjusted YLD using multimorbidity prevalence derived from National Health Insurance Service data. The 5 most common diseases by sex and age groups were selected as diseases of interest. No significant differences were found between YLD estimations made using actual data and Monte-Carlo simulations, even though assumptions about the independent occurrence of diseases should be carefully applied. The prevalence was not well reflected according to disease characteristics in those under the age of 30, among whom there was a difference in YLD between the 2 methods. Therefore, when calculating the burden of diseases for Koreans over the age of 30, it is possible to calculate the YLD with correction for multimorbidity through Monte-Carlo simulation, but care should be taken with under-30s. It is useful to apply the efficiency and suitability of calibration for multiplicative methods using Monte-Carlo simulations in research on the domestic disease burden, especially in adults in their 30s and older. Further research should be carried out on multimorbidity correction methodology according to the characteristics of multiple diseases by sex and age.

Feasibility of Solar Tracking System for PV Panel in Sunbelt Region

In the study of the feasibility of solar tracking systems for crystalline silicon photovoltaic (PV) panels in hot and cold regions, it is argued recently that a tracking system is not necessary for sunbelt countries owing to the overheating that results from excessive exposure to solar irradiance. This conclusion has been formulated based on a mathematical model, which in turn is based on the assumption that the PV module temperature can be calculated using an empirical relation of this temperature to ambient temperature, available solar irradiance, and nominal operation cell temperature (NOCT). To support this conclusion, it is claimed that the mathematical model is validated experimentally. However, this assumption is vague and widely used in the literature. The objective of the present work is to reevaluate the above-mentioned assumption and to discuss the results deriving from it. It is shown experimentally in the present work that the above-mentioned assumption overestimates the PV module temperature. At a solar irradiance of 900 W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , ambient temperature of 25 °C, and wind speed of 5 m/s, the measured PV module temperature is lower than the value calculated based on the mentioned assumption by 29.26%.

Temperature Dependence of Thermoelectric Homogeneity of Noble Metal Thermocouples

This paper describes the results of low-temperature investigations of the thermoelectric inhomogeneity of conventional standardized noble metal thermocouples (types S and R, Au/Pt and Pt/Pd thermocouples) and of non-standardized Pt/Rh-alloyed thermocouples which have undergone initial annealing at 400 °C for 24 h. The investigations aim to verify the generally accepted practice of using a linear relationship between the inhomogeneity and the measured electromotive force (emf). Immersion profile measurements were carried out in a salt bath at temperatures of about 200 °C, 300 °C, 400 °C, and 500 °C. These temperatures are below the critical temperature range of the selective Rh oxidation of Pt/Rh-alloyed thermocouples. Therefore, the results of the homogeneity investigations should not be influenced by such reversible oxidations effects. Nevertheless, the results of the homogeneity tests at 500 °C showed a deviation from the linearity of the measured inhomogeneities of the thermocouples containing Pt/Rh alloys related to the measurements at 200 °C, 300 °C, and 400 °C. The results obtained with the Au/Pt and Pt/Pd thermocouples confirmed the above-mentioned assumption of the linear relationship between the magnitude of the inhomogeneities and the thermoelectric voltages measured. An additional investigation of a multi-wire thermocouple consisting of non-standardized Pt/Rh alloys (Pt5%Rh, Pt17%Rh, and Pt20%Rh) and a pure platinum thermoelement confirmed the results obtained with the standardized type S and R thermocouples and allowed conclusions to be drawn about re-ordering effects of the Pt/Rh-alloyed thermocouples, which are strongly related to the initial annealing temperature of 400 °C.

Cultural values and practices: the pillars of heritage language maintenance endeavours within an immigrant multilingual Malayali community in the UK

ABSTRACT The widespread marginalisation of heritage languages in public and political discourse coupled with the association of proficiency in host languages with personal and professional gain have led many diasporic communities to shy away from transmitting their heritage languages at home (Curdt-Christiansen 2016): a context considered to be optimal for minority language maintenance (Vaccarino 2011). This does not imply however that attempts-on the part of migrants-to keep alive their heritage languages, are non-existent. Demonstrating a harmonious convergence between their everyday language practices and the above-mentioned assumption that the home is a ‘stronghold' for heritage language use (Pauwels 2016 p.90) are a Malayali community based in Yorkshire, England. Making this a possibility was their commitment towards maintaining certain cultural practices and values associated with the first-generation migrants' country of origin, India. Drawing on semi-structured interview responses, observational field notes and audio-recorded family conversations obtained from this community, what I thus propose in this paper is that these cultural values and practices form the pillars that support the Malayalis’ attempts to preserve their heritage language Malayalam. Furthermore, my findings suggest the agents behind these endeavours to pan across three generations, in two countries: the UK and India.

The Roots of Violence in Western Social Theories: In Search of Solution for Islam and Modernity

I argue that if we recognize the roots of violence in modern social theories, we may have at least a picture of how to solve the problem of violence for both Islam and modernity. I use the term “violence” to refer to an idea or an action that explicitly endorses revolt or physical conflict in attaining a goal. I will review fourteen social theories of the colonial and post-colonial period from the beginning to the end of the Twentieth Century, as presented by Charles Lemert in his book, Social Theory: The Multicultural &amp; Classic Readings (1993). I refer my understanding of violence and its solutions for Islam and modernity on my interpretation of the types of abuse that I took from Lemert’s book. I discuss my argument in the following subtitles. The first subtitle is an introduction to capitalism as the answer to Islam and modernity. The second item is my finding of the notion of violence as a concept that is originated in the Western social theories of the colonial period. The third point is the degree to which I find that the roots of violence are also originated in the Western social methods of the post-colonial period. The fourth point of my article conveys the term “violence” used in linguistics by two French philosophers: Jacques Derrida and Michelle Foucault. The fifth element concludes this article by strengthening the above-mentioned assumption.

Comparison of elementary price indices

Most countries use the Dutot, Jevons or Carli index for the calculation of their Consumer Price Index (CPI) at the lowest (elementary) level of aggregation. The choice of the elementary formula for inflation measurement does matter and the effect of the change of the index formula was estimated by the Bureau of Labor Statistics. It has been shown that difference between elementary indices can be explained in terms of changes in price dispersion. In this article, we extend these results comparing both population and sample elementary indices. We assume that prices from two compared time moments are log-normally distributed and correlated. Under the above-mentioned assumption, we provide formulas for biases and mean-squared errors of main elementary indices.

A Telescopic Bregmanian Proximal Gradient Method Without the Global Lipschitz Continuity Assumption

The problem of minimization of the sum of two convex functions has various theoretical and real-world applications. One of the popular methods for solving this problem is the proximal gradient method (proximal forward–backward algorithm). A very common assumption in the use of this method is that the gradient of the smooth term is globally Lipschitz continuous. However, this assumption is not always satisfied in practice, thus casting a limitation on the method. In this paper, we discuss, in a wide class of finite- and infinite-dimensional spaces, a new variant of the proximal gradient method, which does not impose the above-mentioned global Lipschitz continuity assumption. A key contribution of the method is the dependence of the iterative steps on a certain telescopic decomposition of the constraint set into subsets. Moreover, we use a Bregman divergence in the proximal forward–backward operation. Under certain practical conditions, a non-asymptotic rate of convergence (that is, in the function values) is established, as well as the weak convergence of the whole sequence to a minimizer. We also obtain a few auxiliary results of independent interest.

Exact analysis of the least‐mean‐square algorithm with coloured measurement noise

In general, theoretical analyses of adaptive filtering algorithms employ statistical approximations in order to render the derivations tractable. Among such hypotheses, the statistical independence between the current adaptive coefficients and past input vectors is a very popular one. Unfortunately, this simplification gives rise to discrepancies with respect to empirical results, especially for large values of the step-size parameter. In this Letter, this issue is overcome by the usage of an exact expectation analysis (i.e. a stochastic model that does not employ the above-mentioned independence assumption) of the least-mean-squares adaptive algorithm. The authors analysis is also generalised in order to address the common case of coloured additive noise, an issue that is so far missing from the literature. The accuracy of the advanced model is verified through simulations.

The interaction between telicity and agentivity: Experimental evidence from intransitive verbs in German and Chinese

Telicity and agentivity are semantic factors that split intransitive verbs into (at least two) different classes. Clear-cut unergative verbs, which select the auxiliary HAVE, are assumed to be atelic and agent-selecting; unequivocally unaccusative verbs, which select the auxiliary BE, are analyzed as telic and patient-selecting. Thus, agentivity and telicity are assumed to be inversely correlated in split intransitivity. We will present semantic and experimental evidence from German and Mandarin Chinese that casts doubts on this widely held assumption. The focus of our experimental investigation lies on variation with respect to agentivity (specifically motion control, manipulated via animacy), telicity (tested via a locative vs. goal adverbial), and BE/HAVE-selection with semantically flexible intransitive verbs of motion. Our experimental methods are acceptability ratings for German and Chinese (Experiments 1 and 2) and event-related potential (ERP) measures for German (Experiment 3). Our findings contradict the above-mentioned assumption that agentivity and telicity are generally inversely correlated and suggest that for the verbs under study, agentivity and telicity harmonize with each other. Furthermore, the ERP measures reveal that the impact of the interaction under discussion is more pronounced on the verb lexeme than on the auxiliary. We also found differences between Chinese and German that relate to the influence of telicity on BE/HAVE-selection. They seem to confirm the claim in previous research that the weight of the telicity factor locomotion (or internal motion) is cross-linguistically variable.

Fully Incrementing Visual Cryptography From a Succinct Non-Monotonic Structure

Visual cryptography (VC) is a variant form of secret sharing. In general threshold setting, the $k$ -out-of- $n$ VC allows that, in a set of $n$ participants, any $k$ can recover and reconstruct the secret by stacking their shares. Recently, the notion of multiple-secret VC has been introduced to embed multiple secrets. Region incrementing visual cryptography (RIVC) is referred to as a new type of multi-secret VC. RIVC defines $s$ layers and takes $s$ secrets, and then embeds each secret into each layer. The layers are defined by the number of participants; for example, let two secrets and two layers be $S_{2},S_{3}$ and $L_{2},L_{3}$ in two-out-of-three RIVC, where any two participants in $L_{2}$ can recover $S_{2}$ and three in $L_{3}$ can recover $S_{2},S_{3}$ . However, there is another multi-secret VC, called fully incrementing visual cryptography (FIVC), which also has the layers, but only one secret $S_{i}$ will reveal in one layer $L_{i}$ . In this paper, our stating point is to propose a new notion of non-monotonic visual cryptography (NVC) for human vision system as a primitive to construct FIVC. We first present an ideal construction of simple NVC, which relies on a slightly unreasonable assumption. Based on the simple NVC, we show a few methods to extend the functionality for complicated cases of NVC. Then, the generic construction is presented as a systematic manner to eliminate the above-mentioned assumption. Finally, we formally introduce a transformation NVC-to-FIVC algorithm, which takes NVC as input and then produce a construction of FIVC. Also, show a demonstration the NVC-to-RIVC algorithm, and analyze some properties regarding NVC. We believe that the notion of NVC can potentially find other applications and is of independent interest.

Beyond Cartesianism: Body-perception and the immediacy of empathy

The current debates dealing with empathy, social cognition, and the problem of other minds widely accept the assumption that, whereas we can directly perceive the other’s body, certain additional mental operations are needed in order to access the contents of the other’s mind. Body-perception has, in other words, been understood as something that merely mediates our experience of other minds and requires no philosophical analysis in itself. The available accounts have accordingly seen their main task as pinpointing the operations and mechanisms that enable us to move beyond body-perception—and here acts such as inference, simulation, and projection have usually been the main candidates. This whole setting, however, seems to rely on a somewhat Cartesian assumption, according to which body-perception fundamentally amounts to the perception of a material thing, res extensa, starting from which we then strive to grasp the other as a res cogitans. Insofar as one begins with the question of how we can discover and understand mindedness in things that cannot be directly perceived as minded, the Cartesian setting is already taken for granted—and this is, in fact, exactly what most of the available proposals seem to be doing. From a phenomenological point of view, the Cartesian setting is untenable and seriously misleads the whole debate. The present article reassesses the role and status of body-perception in empathy. Making use of the Husserlian theory of expressivity in particular, the article engages a phenomenological framework of analysis, challenges the above-mentioned assumption concerning the nature of body-perception, and argues for the immediate nature of empathy.

AUKŠTOS KVALIFIKACIJOS MIGRANTŲ SUGRĮŽIMAS: AR UŽSIENYJE ĮGYTOS ŽINIOS IR ĮGŪDŽIAI PADEDA ĮSITVIRTINTI LIETUVOS DARBO RINKOJE?

While the concepts of brain drain and brain waste are frequently used to analyse migration from Central and Eastern Europe, this paper starts with an assumption that mobile workers usually gain important skills and knowledge which may help them to return and integrate into the labour market of the home country. Furthermore, this paper focusses on a very specific group for whom the above-mentioned effect is all the more likely: the highly qualified migrants defined narrowly as people with high education who held qualified jobs when working abroad. In this paper, the above-mentioned assumption is tested empirically, drawing on a number of surveys (representative surveys of Lithuanian residents, employers and returnees, a survey of graduates of the “Create for Lithuania” programme, an internet-based survey of highly qualified returnees) and interviews. We found that professional aims (such as the intention to take advantage of their skills and knowledge) were very important reasons for return, although they worked in parallel with broader family and home-sickness motives. In addition, around 2/3 of returnees in our sample mentioned that they wanted to contribute to the progress of Lithuania, and the majority of them agreed that they succeeded in doing that. The data also showed that most of the returnees in our target group were able to find employment without major difficulties. The majority of respondents indicated that skills and knowledge they gained abroad were very useful both for finding a job and pursuing a further career. We identified a number of structural factors that sometimes help and sometimes hinder the integration of the returnees. The returnees did take into consideration the improving economic outlook of the country (while many EU countries have been stagnating) and a rather high standard of the quality of life (in Vilnius). While the majority in the society and among the employers are quite sceptical about the human capital of the returnees (because they consider return as an evidence of failure), they are more receptive towards the highly qualified persons. In turn, the returnees themselves have to deal with a limited number and rather specific circle of potential employers where the appreciation of foreign experience is more likely (e. g., foreign-own companies). Furthermore, the returnees in our sample were also relatively skilled at presenting themselves and had many options for signalling their labour market credentials (such as diplomas, recommendations or brands of their foreign employers). In addition, a significant number of returnees do choose to become self-employed or start their own business. The public sector has played a contradictory role. On the one hand, the returnees were quite sceptical about the Lithuanian public sector in general (too much bureaucracy was the key criticism) and its migration policy efforts in particular. The continuous stalemate with regard to the double citizenship issue was frequently quoted as a symbol of the state being at odds with the needs of its mobile population. The returnees who actually returned to the public sector (six of our interviewees were university researchers) argued that gaining a permanent teaching or research position for scientists from “outside” is still way too difficult, the level of internationalisation and internal cooperation is too limited, and research agenda in humanities is too self-centred on national topics. On the other hand, some migrants returned in response to public sector initiatives, such as the programme for young professionals “Create for Lithuania”, EU-supported research grants, and the FDI policy that helped to attract some large employers of highly qualified employees (such as the IT unit of the Barclays bank). Our research also showed the continuing demand for “traditional” migration policy measures such as informing the returnees and helping their children to integrate into the system of secondary education.

Exoplanet hosts reveal lithium depletion

Aims. We study the impact of the presence of planets on the lithium abundance of host stars and evaluate the previous claim that planet hosts exhibit lithium depletion when compared to their non-host counterparts. Methods. Using previously published lithium abundances, we remove the confounding effect of the different fundamental stellar parameters by applying a multivariable regression on our dataset. In doing so, we explicitly make an assumption made implicitly by different authors: that lithium abundance depends linearly on fundamental stellar parameters. Using a moderator variable to distinguish stars with planets from those without, we evaluate the existence of an offset in lithium abundances between the two groups. We perform this analysis first for stars that present a clear lithium detection exclusively and include in a second analysis upper lithium measurements. Results. Our analysis shows that under the above-mentioned assumption of linearity, a statistically significant negative offset in lithium abundance between planet hosts and non-hosts is recovered. We concluded that an inflation on the lithium uncertainty estimations by a factor of larger than 5 is required to render the measured offset compatible with zero at less than 3-4 {\sigma} and make it non-significant. We demonstrated that the offset as delivered by our method depends on the different nature of the stars in the two samples. We did so by showing that the offset is reduced down to zero if the planet-host stars are replaced by comparison stars. Moreover, the measured depletion is still significant when one imposes different constraints on the dataset, such as a limit in planetary mass or constrain the host temperature to around solar value. We conclude then that planet-host stars exhibit enhanced lithium depletion when compared with non-host stars. (abridged)

Development of quartz c-axis crossed/single girdles under simple-pure shear deformation: Results of visco-plastic self-consistent modeling

Quartz c-axis fabrics are widely used to determine the shear plane in ductile shear zones, based upon an assumption that the shear plane is perpendicular to both the central segment of quartz c-axis crossed girdle and single girdle. In this paper the development of quartz c-axis fabric under simple-pure shear deformation is simulated using the visco-plastic self-consistent (VPSC) model so as to re-examine this assumption. In the case of no or weak dynamic recrystallization, the simulated crossed girdles have a central segment perpendicular or nearly perpendicular to the maximum principal finite strain direction (X) and the XY finite strain plane, and at a variable angle relative to the imposed kinematic framework that is dependent on the modeled flow vorticity and finite strain. These crossed girdles have a symmetrical skeleton with respect to the finite strain axes, regardless of the bulk strain and the kinematic vorticity, and rotate in a way similar to the shear sense with increasing bulk strain ratio. The larger the vorticity number the more asymmetrical their legs tend to be. In the case of strong dynamic recrystallization and large bulk strain, under simple shear the crossed girdle switches into single girdles, sub-perpendicular to the shear plane, by losing the weak legs. The numerical results in our models do not confirm the above-mentioned assumption.

“Well, I'm Dashed!”

“Well, I'm Dashed!”

Relative localization for wireless sensor networks with linear topology

Sensors can be deployed along a road or a bridge to form a wireless sensor network with a linear topology where nodes have a spatial ordering. This spatial characteristic indicates relative locations for nodes and facilitates such functions as object tracking and monitoring in the network. We attempt to derive this ordering with RSSI (Received Signal Strength Indicator) as the only input, which does not require attaching extra hardware to the sensor nodes. This requires a method for translating RSSI into spatial constraints. There are two candidate methods in the literature. The first method uses connectivity information among the nodes to calculate their relative locations. But analysis of real-world trace data indicates that it does not work well in reality. The second method assumes that closer nodes receive higher RSSI. However, we have proved that the relative localization problem is actually NP-hard under such an assumption. Fortunately, the problem turns out to be efficiently solvable if we adopt a new observation slightly different from the above-mentioned closer-higher RSSI assumption. This observation that the closest node always receives the highest RSSI is verified by the analytical results of the same real-world trace data. We then propose a spatial ordering method based on the observation, and evaluate it through various field experiments. Results show that the proposed method achieves an accuracy of over 99%.

Optical Characterization and Computational Chemical Evaluation of Electronic Localized States in Polyolefin

SUMMARY Optical absorption spectra and photoluminescence spectra were obtained for eight kinds of polyolefin sheet samples using photons in a range from visible to vacuum ultraviolet (UV). Almost all samples were found to exhibit an absorption peak at around 6.5 eV and a luminescence band at around 4.3 eV. The luminescence was found to be induced by the absorption. Furthermore, it was found that successive absorption of UV photons weakened the luminescence intensity. It is assumed from these results that -unsaturated carbonyls are luminous and that the carbonyls are decomposed through the Norrish type II reaction by absorbing UV photons. Quantum chemical calculations were carried out using polyethylene models with and without an unsaturated carbonyl to verify the above-mentioned assumption. As a result, the model with an unsaturated carbonyl was found to have localized electronic states in the forbidden band. One of the differential energies between the states is close to the photon energy, by which the luminescence is induced. The bond length of a double bond, which is next to the carbonyl, was found to be longer at the excited singlet state than at the ground state. These results obtained by computation support the above-mentioned assumption of the luminescence center and its decomposition.

Gaussian Specific Compensation for Channel Distortion in Speech Recognition

Channel distortion is one of the major factors degrading the performance of automatic speech recognition (ASR) systems. Most of the current compensation methods rely on the assumption that the channel distortion remains unchanged within an utterance or globally. However, we show in this letter that the distortion varies over speech frames even if the channel response is unchanged. To address this problem, we relax the above-mentioned assumption and propose a new method to compensate the channel distortion for each Gaussian of the acoustic models. Firstly, we derive the relationship between the clean and distorted models, and then estimate the channel magnitude response with the expectation-maximization (EM) algorithm. Finally, we obtain the matched models with the estimated magnitude response and the clean models. Experiments were conducted on the TIMIT/NTIMIT databases and the results confirmed the effectiveness of the proposed method.