Generalized Propagation Channel Model for 2GHz Low Elevation Links Using a Ray-tracing Method

Unmanned Aerial Vehicles (UAV) will increasingly be used for responding to emergencies or for law enforcement in civil surveillance applications. Transferring the enormous amounts of information from UAV-mounted cameras or sensors will require large bandwidths, unlike the information required for remotely controlling a UAV, thus necessitating higher frequency bands typically in the vicinity of 2 or 5 GHz. Novel hardware developments will need to rely on a versatile propagation channel model for the envisaged scenarios ranging from deep shadow urban areas to open fields. This paper studies more complex intermediate scenarios, which fall between the aforementioned ones, and which are more difficult to model. A semi-deterministic model, first developed for open, flat areas, has been generalized to accommodate any possible operational scenario and was tested in built-up areas. The model involves a stochastic part and a determinist which is a ray-tracing based part used to compute the long term mean (LTM) of the signal's coherent component

Progress in a social work writing course: Self-efficacy, course objectives, and skills

Although instructors express concerns about social work students’ writing skills, little research has been conducted. One remedy is a social work-focused writing course. This study assessed a required writing course with a sample of 49 baccalaureate students. From online pre- and post-test surveys, two student outcomes improved significantly: self-reported scores for writing self-efficacy and competence in course objectives. On-demand writing samples improved significantly based on anonymous rating by the course instructors; however, blind ratings found gains but not at a significant level. Improved outcomes were not associated with demographic or background characteristics. We discuss limitations of the study and implications for social work education

Application of Compromise Programming to a semi-detached housing development in order to balance economic and environmental criteria

This is a post-peer-review, pre-copyedit version of an article published in Journal of the Operational Research Society. The definitive publisher-authenticated version: Ruá Aguilar, MJ.; Guadalajara Olmeda, MN. (2012). Application of Compromise Programming to a semi-detached housing development in order to balance economic and environmental criteria. Journal of the Operational Research Society. 64(3):459-468, is available online at: http://www.palgrave-journals.com/jors/journal/v64/n3/full/jors201276a.html.European Energy Performance of Buildings Directives DE promote energy efficiency in buildings. Under these Directives, the European Union States must apply minimum requirements regarding the energy performance of buildings and ensure the certification of their energy performance. The Directives set only the basic principles and requirements, leaving a significant amount of room for the Member States to establish their specific mechanisms, numeric requirements and ways to implement them, taking into account local conditions. With respect to the Spanish case, the search for buildings that are more energy efficient results in a conflict between users¿ economic objectives and society's environmental objectives. In this paper, Compromise Programming is applied to help in the decision-making process. An appropriate distribution of types of dwellings, according to their energy performance and to the climatic zone considered in Spain, will be suggested. Results provide a compromise solution between both objectives.Ruá Aguilar, MJ.; Guadalajara Olmeda, MN. (2012). Application of Compromise Programming to a semi-detached housing development in order to balance economic and environmental criteria. Journal of the Operational Research Society. 64(3):459-468. doi:10.1057/jors.2012.76S459468643Andaloro, A. P. F., Salomone, R., Ioppolo, G., & Andaloro, L. (2010). Energy certification of buildings: A comparative analysis of progress towards implementation in European countries. Energy Policy, 38(10), 5840-5866. doi:10.1016/j.enpol.2010.05.039André, F. J., Cardenete, M. A., & Romero, C. (2008). Using compromise programming for macroeconomic policy making in a general equilibrium framework: theory and application to the Spanish economy. Journal of the Operational Research Society, 59(7), 875-883. doi:10.1057/palgrave.jors.2602415Baja, S., Chapman, D. M., & Dragovich, D. (2006). Spatial based compromise programming for multiple criteria decision making in land use planning. Environmental Modeling & Assessment, 12(3), 171-184. doi:10.1007/s10666-006-9059-1Ballestero, E., & Romero, C. (1991). A theorem connecting utility function optimization and compromise programming. Operations Research Letters, 10(7), 421-427. doi:10.1016/0167-6377(91)90045-qBallestero, E., & Romero, C. (1993). Weighting in compromise programming: A theorem on shadow prices. Operations Research Letters, 13(5), 325-329. doi:10.1016/0167-6377(93)90055-lDavies, H., & Wyatt, D. (2004). Appropriate use of the ISO 15686-1 factor method for durability and service life prediction. Building Research & Information, 32(6), 552-553. doi:10.1080/0961321042000291938Diakaki, C., Grigoroudis, E., Kabelis, N., Kolokotsa, D., Kalaitzakis, K., & Stavrakakis, G. (2010). A multi-objective decision model for the improvement of energy efficiency in buildings. Energy, 35(12), 5483-5496. doi:10.1016/j.energy.2010.05.012Dı́az-Balteiro, L., & Romero, C. (2003). Forest management optimisation models when carbon captured is considered: a goal programming approach. Forest Ecology and Management, 174(1-3), 447-457. doi:10.1016/s0378-1127(02)00075-0Diaz-Balteiro, L., & Rodriguez, L. C. E. (2006). Optimal rotations on Eucalyptus plantations including carbon sequestration—A comparison of results in Brazil and Spain. Forest Ecology and Management, 229(1-3), 247-258. doi:10.1016/j.foreco.2006.04.005Fattahi, P., & Fayyaz, S. (2009). A Compromise Programming Model to Integrated Urban Water Management. Water Resources Management, 24(6), 1211-1227. doi:10.1007/s11269-009-9492-4Hamdy, M., Hasan, A., & Siren, K. (2011). Applying a multi-objective optimization approach for Design of low-emission cost-effective dwellings. Building and Environment, 46(1), 109-123. doi:10.1016/j.buildenv.2010.07.006Johnstone, I. M. (2001). Energy and mass flows of housing: a model and example. Building and Environment, 36(1), 27-41. doi:10.1016/s0360-1323(99)00065-7Johnstone, I. M. (2001). Energy and mass flows of housing: estimating mortality. Building and Environment, 36(1), 43-51. doi:10.1016/s0360-1323(99)00066-9Linares, P., & Romero, C. (2000). A multiple criteria decision making approach for electricity planning in Spain: economic versus environmental objectives. Journal of the Operational Research Society, 51(6), 736-743. doi:10.1057/palgrave.jors.2600944Rey, F. J., Velasco, E., & Varela, F. (2007). Building Energy Analysis (BEA): A methodology to assess building energy labelling. Energy and Buildings, 39(6), 709-716. doi:10.1016/j.enbuild.2006.07.009Rudbeck, C. (2002). Service life of building envelope components: making it operational in economical assessment. Construction and Building Materials, 16(2), 83-89. doi:10.1016/s0950-0618(02)00003-xSan-José, J. T., Losada, R., Cuadrado, J., & Garrucho, I. (2007). Approach to the quantification of the sustainable value in industrial buildings. Building and Environment, 42(11), 3916-3923. doi:10.1016/j.buildenv.2006.11.013Yu, P. L. (1973). A Class of Solutions for Group Decision Problems. Management Science, 19(8), 936-946. doi:10.1287/mnsc.19.8.936Zelany, M. (1974). A concept of compromise solutions and the method of the displaced ideal. Computers & Operations Research, 1(3-4), 479-496. doi:10.1016/0305-0548(74)90064-

Standstill Electric Charge Generates Magnetostatic Field Under Born-Infeld Electrodynamics

The Abelian Born-Infeld classical non-linear electrodynamic has been used to investigate the electric and magnetostatic fields generated by a point-like electrical charge at rest in an inertial frame. The results show a rich internal structure for the charge. Analytical solutions have also been found. Such findings have been interpreted in terms of vacuum polarization and magnetic-like charges produced by the very high strengths of the electric field considered. Apparently non-linearity is to be accounted for the emergence of an anomalous magnetostatic field suggesting a possible connection to that created by a magnetic dipole composed of two mognetic charges with opposite signals. Consistently in situations where the Born-Infeld field strength parameter is free to become infinite, Maxwell`s regime takes over, the magnetic sector vanishes and the electric field assumes a Coulomb behavior with no trace of a magnetic component. The connection to other monopole solutions, like Dirac`s, t' Hooft`s or Poliakov`s types, are also discussed. Finally some speculative remarks are presented in an attempt to explain such fields.Comment: 11 pages, 3 figures. In this version is update a permanent address of the author L.P.G. De Assis and information on submission publication. Submetted to International Journal of Theoretical Physic

Early Detection of COVID-19 in Female Athletes Using Wearable Technology

Background: Heart rate variability (HRV), respiratory rate (RR), and resting heart rate (RHR) are common variables measured by wrist-worn activity trackers to monitor health, fitness, and recovery in athletes. Variations in RR are observed in lower-respiratory infections, and preliminary data suggest changes in HRV and RR are linked to early detection of COVID-19 infection in nonathletes. Hypothesis: Wearable technology measuring HRV, RR, RHR, and recovery will be successful for early detection of COVID-19 in NCAA Division I female athletes. Study Design: Cohort study. Level of Evidence: Level 2. Methods: Female athletes wore WHOOP, Inc. bands through the 2020 to 2021 competitive season. Of the athletes who tested positive for COVID (n = 33), 14 had enough data to be assessed (N = 14; 20.0 ± 1.3 years; 69.8 ± 7.2 kg; 172.0 ± 8.3 cm). Roughly 2 weeks of noninfected days were used to set baseline levels of HRV, RR, recovery, and RHR to compare with -3, -2, and -1 days before a positive COVID-19 result. Results: Increases in RR (P = 0.02) were detected on day -3. RHR (P \u3c 0.01) and RR increased (P \u3c 0.01), while HRV decreased (P \u3c 0.05) on day -1, compared with baseline. Differences were noted in all variables on the day of the positive COVID-19 result: decreased HRV (P \u3c 0.05) and recovery scores (P \u3c 0.01), and increased RHR (P \u3c 0.01) and RR (P \u3c 0.01). Conclusion: In female athletes, wearable technology was successful in predicting COVID-19 infection through changes in RR 3 days before a positive test, and also HRV and RHR the day before a positive test. Clinical Relevance: Wearable technology may be used, as part of a multifaceted approach, for the early detection of COVID-19 in elite athletes through monitoring of HRV, RR, and RHR for overall team health

The MetNet vehicle: a lander to deploy environmental stations for local and global investigations of Mars

Investigations of global and related local phenomena on Mars such as atmospheric circulation patterns, boundary layer phenomena, water, dust and climatological cycles and investigations of the planetary interior would benefit from simultaneous, distributed in situ measurements. Practically, such an observation network would require low-mass landers, with a high packing density, so a large number of landers could be delivered to Mars with the minimum number of launchers. The Mars Network Lander (MetNet Lander; MNL), a small semi-hard lander/penetrator design with a payload mass fraction of approximately 17 %, has been developed, tested and prototyped. The MNL features an innovative Entry, Descent and Landing System (EDLS) that is based on inflatable structures. The EDLS is capable of decelerating the lander from interplanetary transfer trajectories down to a surface impact speed of 50-70 ms(-1) with a deceleration of < 500 g for < 20 ms. The total mass of the prototype design is approximate to 24 kg, with approximate to 4 kg of mass available for the payload. The EDLS is designed to orient the penetrator for a vertical impact. As the payload bay will be embedded in the surface materials, the bay's temperature excursions will be much less than if it were fully exposed on the Martian surface, allowing a reduction in the amount of thermal insulation and savings on mass. The MNL is well suited for delivering meteorological and atmospheric instruments to the Martian surface. The payload concept also enables the use of other environmental instruments. The small size and low mass of a MNL makes it ideally suited for piggy-backing on larger spacecraft. MNLs are designed primarily for use as surface networks but could also be used as pathfinders for high-value landed missions

Managing the Knowledge Creation Process of Large-Scale Evaluation Campaigns

Περιέχει το πλήρες κείμενοThis paper discusses the evolution of large-scale evaluation campaigns and the corresponding evaluation infrastructures needed to carry them out. We present the next challenges for these initiatives and show how digital library systems can play a relevant role in supporting the research conducted in these fora by acting as virtual research environments

Pre-sleep feeding, sleep quality, and markers of recovery in division I NCAA female soccer players

Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band – a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively – 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration (p = 0.10, 0.69, 0.16, 0.17) and sleep disturbances (p = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery (p = 0.81, 0.06, 0.81, 0.92), RHR (p = 0.84, 0.64, 0.26, 0.66), or HRV (p = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery