27,854 research outputs found
A non-proposition-wise variant of majority voting for aggregating judgments
Majority voting is commonly used in aggregating judgments. The literature to date on judgment
aggregation (JA) has focused primarily on proposition-wise majority voting (PMV). Given a set of issues
on which a group is trying to make collective judgments, PMV aggregates individual judgments issue by
issue, and satisfies a salient property of JA rules—independence. This paper introduces a variant of
majority voting called holistic majority voting (HMV). This new variant also meets the condition of
independence. However, instead of aggregating judgments issue by issue, it aggregates individual
judgments en bloc. A salient and straightforward feature of HMV is that it guarantees the logical
consistency of the propositions expressing collective judgments, provided that the individual points of
view are consistent. This feature contrasts with the known inability of PMV to guarantee the consistency
of the collective outcome. Analogously, while PMV may present a set of judgments that have been
rejected by everyone in the group as collectively accepted, the collective judgments returned by HMV
have been accepted by a majority of individuals in the group and, therefore, rejected by a minority of
them at most. In addition, HMV satisfies a large set of appealing properties, as PMV also does. However,
HMV may not return any complete proposition expressing the judgments of the group on all the issues at
stake, even in cases where PMV does. Moreover, demanding completeness from HMV leads to
impossibility results similar to the known impossibilities on PMV and on proposition-wise JA rules in
genera
Whole-body heat stress and exercise stimulate the appearance of platelet microvesicles in plasma with limited influence of vascular shear stress
Intense, large muscle mass exercise increases circulating microvesicles, but our understanding of microvesicle dynamics and mechanisms inducing their release remains limited. However, increased vascular shear stress is generally thought to be involved. Here, we manipulated exercise-independent and exercise-dependent shear stress using systemic heat stress with localized single-leg cooling (low shear) followed by single-leg knee extensor exercise with the cooled or heated leg (Study 1, n = 8) and whole-body passive heat stress followed by cycling (Study 2, n = 8). We quantified femoral artery shear rates (SRs) and arterial and venous platelet microvesicles (PMV-CD41+) and endothelial microvesicles (EMV-CD62E+). In Study 1, mild passive heat stress while one leg remained cooled did not affect [microvesicle] (P ≥ 0.05). Single-leg knee extensor exercise increased active leg SRs by ~12-fold and increased arterial and venous [PMVs] by two- to threefold, even in the nonexercising contralateral leg (P < 0.05). In Study 2, moderate whole-body passive heat stress increased arterial [PMV] compared with baseline (mean±SE, from 19.9 ± 1.5 to 35.5 ± 5.4 PMV.μL-1.103, P < 0.05), and cycling with heat stress increased [PMV] further in the venous circulation (from 27.5 ± 2.2 at baseline to 57.5 ± 7.2 PMV.μL-1.103 during cycling with heat stress, P < 0.05), with a tendency for increased appearance of PMV across exercising limbs. Taken together, these findings demonstrate that whole-body heat stress may increase arterial [PMV], and intense exercise engaging either large or small muscle mass promote PMV formation locally and systemically, with no influence upon [EMV]. Local shear stress, however, does not appear to be the major stimulus modulating PMV formation in healthy humans
An Economic Model-Based Predictive Control to Manage the Users' Thermal Comfort in a Building
The goal of maintaining users' thermal comfort conditions in indoor environments may require complex regulation procedures and a proper energy management. This problem is being widely analyzed, since it has a direct effect on users' productivity. This paper presents an economic model-based predictive control (MPC) whose main strength is the use of the day-ahead price (DAP) in order to predict the energy consumption associated with the heating, ventilation and air conditioning (HVAC). In this way, the control system is able to maintain a high thermal comfort level by optimizing the use of the HVAC system and to reduce, at the same time, the energy consumption associated with it, as much as possible. Later, the performance of the proposed control system is tested through simulations with a non-linear model of a bioclimatic building room. Several simulation scenarios are considered as a test-bed. From the obtained results, it is possible to conclude that the control system has a good behavior in several situations, i.e., it can reach the users' thermal comfort for the analyzed situations, whereas the HVAC use is adjusted through the DAP; therefore, the energy savings associated with the HVAC is increased.Spanish Ministry of Science and Innovation [DPI2014-56364-C2-1-R]; EU-ERDF funds; Competitiveness and ERDF funds; Fundacion Iberdrola Espana; Portuguese Foundation for Science & Technology, through IDMEC, under LAETA [ID/EMS/50022/2013
Field study on adaptive thermal comfort in typical air conditioned classrooms
This study investigates adaptive thermal comfort in air conditioned classrooms in Hong Kong. A field survey was conducted in several typical classrooms at the City University of Hong Kong. This survey covered objective measurement of thermal environment parameters and subjective human thermal responses. A total of 982 student volunteers participated in the investigation. The results indicate that students in light clothing (0.42 clo) have adapted to the cooler classroom environments. The neutral temperature is very close to the preferred temperature of approximately 24 °C. Based on the MTSV ranging between −0.5 and + 0.5, the comfort range is between 21.56 °C and 26.75 °C. The lower limit is below that of the ASHRAE standard. Of the predicted mean vote (PMV) and the University of California, Berkeley (UCB) model, the UCB model predictions agree better with the mean thermal sensation vote (MTSV). Also, the respective fit regression models of the MTSV versus each of the following: operative temperature (Top), PMV, and UCB were obtained. This study provides a better understanding of acceptable classroom temperatures
The role of platelet microvesicles in intercellular communication.
In recent years, there has been exponential growth in the interest in microvesicles, which is reflected by the number of publications. Initially referred to as platelet dust by Peter Wolf in 1967, platelet microvesicles (PMV) are now recognized as important mediators of intercellular communication. There are examples of PMV exerting physiological effects on almost all hematological and vascular cell types, including monocytes, macrophages, neutrophils, T-cells, endothelium cells, and smooth muscle cells (SMCs). PMV can exert these effects by multiple methods: extracellular signaling through receptors, transfer of surface molecules, and delivery of intracellular contents including miRNA. Recent work suggests a complex environment in which cellular contents are being shared multi-directionally between multiple cell types. This review will focus on the communicative properties of PMV
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Learning occupants’ indoor comfort temperature through a Bayesian inference approach for office buildings in United States
A carefully chosen indoor comfort temperature as the thermostat set-point is the key to optimizing building energy use and occupants’ comfort and well-being. ASHRAE Standard 55 or ISO Standard 7730 uses the PMV-PPD model or the adaptive comfort model that is based on small-sized or outdated sample data, which raises questions on whether and how ranges of occupant thermal comfort temperature should be revised using more recent larger-sized dataset. In this paper, a Bayesian inference approach has been used to derive new occupant comfort temperature ranges for U.S. office buildings using the ASHRAE Global Thermal Comfort Database. Bayesian inference can express uncertainty and incorporate prior knowledge. The comfort temperatures were found to be higher and less variable at cooling mode than at heating mode, and with significant overlapped variation ranges between the two modes. The comfort operative temperature of occupants varies between 21.9 and 25.4 °C for the cooling mode with a median of 23.7 °C, and between 20.5 and 24.9 °C for the heating mode with a median of 22.7 °C. These comfort temperature ranges are similar to the current ASHRAE standard 55 in the heating mode but 2–3 °C lower in the cooling mode. The results of this study could be adopted as more realistic thermostat set-points in building design, operation, control optimization, energy performance analysis, and policymaking
Trade Reforms and the Survival of the Passenger Motor Vehicle Industry in Australia
The Passenger Motor Vehicle (PMV) industry in Australia experienced extensive trade reforms in the late 1980s which were expected to promote a competitive PMV industry. This paper tests the hypotheses that decreasing protection have had a significant effect on production, imports, exports, labour productivity and organizational innovations (A1); and this effect is particularly evident since 1988 (A2). We have used cointegration analysis to test the hypothesis (A1) and the Chow test for (A2). Our study confirms our two hypotheses.passenger motor vehicle industry, trade reform, labour productivity, organizational innovations
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