Search results for: statistical randomness tests

Authors: Gopi Kandaswamy, P. Balamuralidhar

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Fully autonomous small Unmanned Aerial Vehicles (UAVs) are increasingly being used in many commercial applications. Although a lot of research has been done to develop safe, reliable and durable UAVs, accidents due to electronic and structural failures are not uncommon and pose a huge safety risk to the UAV operators and the public. Hence there is a strong need for an automated health monitoring system for UAVs with a view to minimizing mission failures thereby increasing safety. This paper describes our approach to monitoring the electronic and structural components in a small UAV without the need for additional sensors to do the monitoring. Our system monitors data from four sources; sensors, navigation algorithms, control inputs from the operator and flight controller outputs. It then does statistical analysis on the data and applies a rule based engine to detect failures. This information can then be fed back into the UAV and a decision to continue or abort the mission can be taken automatically by the UAV and independent of the operator. Our system has been verified using data obtained from real flights over the past year from UAVs of various sizes that have been designed and deployed by us for various applications.

Keywords: fault detection, health monitoring, unmanned aerial vehicles, vibration analysis

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Authors: Amir Bak Khoshnevis, Mahdieh Khodadadi, Aghil Lotfi

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For a bluff body, roughness elements in simulating a turbulent boundary layer, leading to delayed flow separation, a smaller wake, and lower form drag. In the present work, flow past a circular cylinder with using tripping wires is studied experimentally. The wind tunnel used for modeling free stream is open blow circuit (maximum speed = 30m/s and maximum turbulence of free stream = 0.1%). The selected Reynolds number for all tests was constant (Re = 25000). The circular cylinder selected for this experiment is 20 and 400mm in diameter and length, respectively. The aim of this research is to find the optimal operation mode. In this study installed some tripping wires 1mm in diameter, with a different number of wires on the circular cylinder and the wake characteristics of the circular cylinder is studied. Results showed that by increasing number of tripping wires attached to the circular cylinder (6, 8, and 10, respectively), The optimal angle for the tripping wires with 1mm in diameter to be installed on the cylinder is 60̊ (or 6 wires required at angle difference of 60̊). Strouhal number for the cylinder with tripping wires 1mm in diameter at angular position 60̊ showed the maximum value.

Keywords: wake of circular cylinder, trip wire, velocity defect, strouhal number

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Authors: Woei-Shyan Lee, Hao-Chien Kao

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The impact deformation and fracture behaviour of cobalt-based Haynes 188 superalloy are investigated by means of a split Hopkinson pressure bar. Impact tests are performed at strain rates ranging from 1×103 s-1 to 5×103 s-1 and temperatures between 25°C and 800°C. The experimental results indicate that the flow response and fracture characteristics of cobalt-based Haynes 188 superalloy are significantly dependent on the strain rate and temperature. The flow stress, work hardening rate and strain rate sensitivity all increase with increasing strain rate or decreasing temperature. It is shown that the impact response of the Haynes 188 specimens is adequately described by the Zerilli-Armstrong fcc model. The fracture analysis results indicate that the Haynes 188 specimens fail predominantly as the result of intensive localised shearing. Furthermore, it is shown that the flow localisation effect leads to the formation of adiabatic shear bands. The fracture surfaces of the deformed Haynes 188 specimens are characterised by dimple- and / or cleavage-like structure with knobby features. The knobby features are thought to be the result of a rise in the local temperature to a value greater than the melting point.

Keywords: Haynes 188 alloy, impact, strain rate and temperature effect, adiabatic shearing

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Authors: Hatem A. El-Mezayen, Ahmed Abdelmajeed, Fatehya Metwally, Usama Elsaly, Salwa Atef

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Tumor metastasis involves the dissemination of malignant cells into the basement membrane and vascular system contributes to the circulating pool of these markers. In this context our aim has been focused on development of a non-invasive. Circulating tumor cells (CTCs) represent a unique liquid biopsy carrying comprehensive biological information of the primary tumor. Herein, we sought to develop a novel score based on the combination of the most significant CTCs biomarkers with and routine laboratory tests for accurate detection of metastatic breast cancer. Methods: Cytokeratin 18 (CK18), Cytokeratin 19 (CK19), and CA15.3 were assayed in metastatic breast cancer (MBC) patients (75), non-MBC patients (50) and healthy control (20). Results: Areas under receiving operating curve (AUCs) were calculated and used for construction on novel score. A novel score named MBC-CTCs = CA15.3 (U/L) × 0.08 + CK 18 % × 2.9 + CK19 × 3.1– 510. That function correctly classified 87% of metastatic breast cancer at cut-off value = 0.55. (i.e great than 0.55 indicates patients with metastatic breast cancer and less than 0.55 indicates patients with non-metastatic breast cancer). Conclusion: MBC-CTCs is a novel, non-invasive and simple can applied to discriminate patients with metastatic breast cancer.

Keywords: metastatic breast cancer, circulating tumor cells, cytokeratin, EpiCam

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Authors: Juan F. Muñoz-Rosas, Rosa M. García-Fernández, Encarnación Álvarez-Verdejo, Pablo J. Moya-Fernández

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Poverty measurement is a very important topic in many studies in social sciences. One of the most important indicators when measuring poverty is the low income proportion. This indicator gives the proportion of people of a population classified as poor. This indicator is generally unknown, and for this reason, it is estimated by using survey data, which are obtained by official surveys carried out by many statistical agencies such as Eurostat. The main feature of the mentioned survey data is the fact that they contain several variables. The variable used to estimate the low income proportion is called as the variable of interest. The survey data may contain several additional variables, also named as the auxiliary variables, related to the variable of interest, and if this is the situation, they could be used to improve the estimation of the low income proportion. In this paper, we use Monte Carlo simulation studies to analyze numerically the performance of estimators based on several auxiliary variables. In this simulation study, we considered real data sets obtained from the 2011 European Union Survey on Income and Living Condition. Results derived from this study indicate that the estimators based on auxiliary variables are more accurate than the naive estimator.

Keywords: inclusion probability, poverty, poverty line, survey sampling

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Authors: Wenxiao Liu, Kun Zhang, Yongqing Li

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Bovine herpesvirus 1, a member of the genus Variellovirus of the subfamily Alphaherpesvirinae, has caused severe economic cost to the bovine industry. In this study, BoHV-1 glycerol protein gD was expressed in insect cells, and the purified gD was immunized in the Balb/C mice to generate monoclonal antibodies. Based on hybridoma cell fusion techniques, 20 monoclonal antibodies against Bovine herpesvirus 1 have been obtained. Further, mAb 3F8 with neutralizing activity and gD were applied to develop a blocking enzyme-linked immunosorbent assay (Elisa) for detecting neutralizing antibodies against BoHV-1, which shows a significant correlation between the blocking Elisa and VNT. The sensitivity and specificity of the test were estimated to be 94.59% and 93.42%, respectively. Furthermore, antibody pairing tests revealed that mAb 1B6 conjugated to fluorescence microspheres was used as the capture antibody, and mAb 3F9 was used as the detectable antibody to establish the immunochromatographic assay (ICS). The ICS was conducted to detect BoHV-1 in bovine samples with high sensitivity, specificity, and good stability. Clinical sample testing revealed that the results of ICS and real-time PCR have a coincidence rate of 95.42%. Our research confirmed that the ICS is a rapid and reliable method for the diagnosis of BoHV-1. In conclusion, our results lay a solid foundation for the prevention and control of BoHV-1 infection.

Keywords: bovine disease, BoHV-1, ELISA, ICS assay

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Authors: Sergio S. De Jesus, Aline Santana, Rubens Maciel Filho

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The objective of this study was to choose and determine a green solvent system with similar extraction efficiencies as the traditional Bligh and Dyer method. Sunflower seed oil was extracted using Bligh and Dyer method with 2-methyltetrahydrofuran and isoamyl using alcohol ratios of 1:1; 2:1; 3:1; 1:2; 3:1. At the same time comparative experiments was performed with chloroform and methanol ratios of 1:1; 2:1; 3:1; 1:2; 3:1. Comparison study was done using 5 replicates (n=5). Statistical analysis was performed using Microsoft Office Excel (Microsoft, USA) to determine means and Tukey’s Honestly Significant Difference test for comparison between treatments (α = 0.05). The results showed that using classic method with methanol and chloroform presented the extraction oil yield with the values of 31-44% (w/w) and values of 36-45% (w/w) using green solvents for extractions. Among the two extraction methods, 2 methyltetrahydrofuran and isoamyl alcohol ratio 2:1 provided the best results (45% w/w), while the classic method using chloroform and methanol with ratio of 3:1 presented a extraction oil yield of 44% (w/w). It was concluded that the proposed extraction method using 2-methyltetrahydrofuran and isoamyl alcohol in this work allowed the same efficiency level as chloroform and methanol.

Keywords: extraction, green solvent, lipids, sugarcane

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Authors: Monika Kulikowska-Pawlak, Katarzyna Bratnicka-Myśliwiec, Tomasz Ingram

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This study seeks to contribute to the literature on firm competitiveness by advancing the perspective of organizational politics that views this process as a driver which creates identifiable differences in firm performance. The hypothesized relationships were tested on the basis of data from 355 Polish medium and large-sized enterprises. Data were analyzed using correlation analysis, EFA and robustness tests. The main result of the conducted analyses proved the coexistence, previously examined in the literature, of corporate entrepreneurship and firm performance. The obtained research findings made it possible to add organizational politics to a wide range of elements determining corporate entrepreneurship, followed by competitive advantage, in addition to antecedents such as strategic leadership, corporate culture, opportunity-oriented resource-based management, etc. Also, the empirical results suggest that four dimensions of organizational politics (dominant coalition, influence exertion, making organizational changes, and information openness) are positively related to firm competitiveness. In addition, these findings seem to underline a supposition that corporate entrepreneurship is an important mediator which strengthens the competitive effects of organizational politics.

Keywords: corporate entrepreneurship, firm competitiveness, organizational politics, sensemaking

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Authors: Abdel-Aziz M. Mohamed, Nermeen Coutry

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Lead time is an important measure of supply chain performance. It impacts both customer satisfactions as well as the total cost of inventory. This paper presents the result of a study on the analysis of the customer order lead-time for a multinational company. In the study, the lead time was divided into three stages: order entry, order fulfillment, and order delivery. A sample of size 2,425 order lines from the company records were considered for this study. The sample data includes information regarding customer orders from the time of order entry until order delivery. Data regarding the lead time of each sage for different orders were also provided. Summary statistics on lead time data reveals that about 30% of the orders were delivered after the scheduled due date. The result of the multiple linear regression analysis technique revealed that component type, logistics parameter, order size and the customer type have significant impact on lead time. Data analysis on the stages of lead time indicates that stage 2 consumes over 50% of the lead time. Pareto analysis was made to study the reasons for the customer order delay in each of the 3 stages. Recommendation was given to resolve the problem.

Keywords: lead time reduction, customer satisfaction, service quality, statistical analysis

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Authors: Svetlana Missina, Anatoliy Shipilov, Alexandr Vavaev

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The purpose of the present study was to investigate the relationship between sprint and vertical jump performance in elite female football players. Twenty four professional female football players (age, 18.6±3.1 years; height, 168.3±6.3 cm, body mass 61.6±7.4 kg; mean±SD) were tested for 30-m sprint time, 10-m sprint time and vertical countermovement (CMJ) and squat (SJ) jumps height. Participants performed three countermovement jumps and three squat jumps for maximal height on a force platform. Mean values of three trials were used in statistical analysis. The displacement of center of mass (COM) during flight phase (e.g. jump height) was calculated using the vertical velocity of the COM at the moment of take-off. 30-m and 10-m sprint time were measured using OptoGait optical system. The best of three trials were used for analysis. A significant negative correlation was found between 30-m sprint time and CMJ, SJ height (r = -0.85, r = -0.79 respectively), between 10-m sprint time and CMJ, SJ height (r = -0.73, r = -0.8 respectively), and step frequency was significantly related to CMJ peak power (r = -0.57). Our study indicates that there is strong correlation between sprint and jump performance in elite female football players, thus vertical jump test can be considered as a good sprint and agility predictor in female football.

Keywords: agility, female football players, sprint performance, vertical jump height

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Authors: Vaidehi Iyer, Konstantin Borozdin

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Time series prediction problems have many important practical applications, but are notoriously difficult for statistical modeling. Recently, machine learning methods have been attracted significant interest as a practical tool applied to a variety of problems, even though developments in this field tend to be semi-empirical. This paper explores application of Long Short Term Memory based Recurrent Neural Networks to the one-step prediction of time series for both trend and stochastic components. Two types of data are analyzed - daily stock prices, that are often considered to be a typical example of a random walk, - and weather patterns dominated by seasonal variations. Results from both analyses are compared, and reinforced learning framework is used to select more efficient between Recurrent Neural Networks and more traditional auto regression methods. It is shown that both methods are able to follow long-term trends and seasonal variations closely, but have difficulties with reproducing day-to-day variability. Future research directions and potential real world applications are briefly discussed.

Keywords: long short term memory, prediction methods, recurrent neural networks, reinforcement learning

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Authors: Dongqi Sun, Juan Tao, Yingying Wu

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This paper reexamines the appropriateness of contrarian trades as a proxy of informed trades, using high frequency Chinese stock data. Employing this measure for 5 minute intervals, a U-shaped intraday pattern of probability of informed trades (PIN) is found for the CSI300 stocks, which is consistent with previous findings for other markets. However, while dividing the trades into different sizes, a reversed U-shaped PIN from large-sized trades, opposed to the U-shaped pattern for small- and medium-sized trades, is observed. Drawing from the mixed evidence with different trade sizes, the price impact of trades is further investigated. By examining the relationship between trade imbalances and unexpected returns, larges-sized trades are found to have significant price impact. This implies that in those intervals with large trades, it is non-contrarian trades that are more likely to be informed trades. Taking account of the price impact of large-sized trades, non-contrarian trades are used to proxy for informed trading in those intervals with large trades, and contrarian trades are still used to measure informed trading in other intervals. A stronger U-shaped PIN is demonstrated from this modification. Auto-correlation and information advantage tests for robustness also support the modified informed trading measure.

Keywords: contrarian trades, informed trading, price impact, trade imbalance

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Authors: Edgar Ochoa, G. Torres-Villasenor

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Superplastic deformation is shown by materials with a fine grain size, usually less than 10 μm, when they are deformed within the strain rate range 10-5 10-1 s-1 at temperatures greater than 0.5Tm, where Tm is the melting point in Kelvin. According to the constitutive equation for superplastic flow, refinement of the grain size would be expected to increase the optimum strain rate and decrease the temperature required for superplastic flow. Ribbons of eutectic Ag-Cu and Bi-Cd alloys were manufactured by using a single roller melt-spinning technique to obtain a fine grain structure for later test in superplastic regime. The eutectics ribbons were examined by scanning electron microscopy and X-Ray diffraction, and the grain size was determined using the image analysis software ImageJ. The average grain size was less than 1 μm. Tensile tests were carried out from 10-4 to 10-1 s-1, at room temperature, to evaluate the superplastic behavior. The largest deformation was shown by the Bi-Cd eutectic ribbons, Ɛ=140 %, despite that these ribbons have a hexagonal unit cell. On the other hand, Ag-Cu eutectic ribbons have a minor grain size and cube unit cell, however they showed a lower deformation in tensile test under the same conditions than Bi-Cd ribbons. This is because the Ag-Cu grew in a strong cube-cube orientation relationship.

Keywords: eutectic ribbon, fine grain, superplastic deformation, cube-cube orientation

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Authors: Sampada Katekar, Namdeo Hedaoo

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Cold Bituminous Emulsion Mixtures (CBEMs) are generally produced by mixing unheated aggregate, binder and filler at ambient temperature. Cold bituminous emulsion mixtures have several environmental and cost-effective benefits. But CBEMs offer poor early life properties too and they require long curing time to achieve maximum strength. The main focus of this study is to overcome inferiority of CBEMs by incorporating Rice Husk Ash (RHA) and Ordinary Portland Cement (OPC). In this study, RHA and OPC are substituted for conventional mineral filler in an increased percentage from 0 to 3% with an increment of 1%. Marshall stability, retained stability and tensile strength tests were conducted to evaluate the enhancement in performance of CBEMs. The experimental results have shown that Marshall stability and tensile strength of CBEMs increased significantly by replacing the conventional mineral filler with RHA and OPC. The addition of RHA and OPC in CBEMs result in a reduction in moisture induced damages. However, stability and tensile strength values of RHA modified CBEMs are higher than that of OPC modified CBEMs.

Keywords: cold bituminous emulsion mixtures, Marshall stability test, ordinary Portland cement, rice husk ash

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Authors: Graciela Soares Marcelli, Elison Eduardo Jardim Bierhals, Luciane Teresa Salvi, Claudineia Brazil, Rafael Haag

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The sun is a source of renewable energy, and its use as both a source of heat and light is one of the most promising energy alternatives for the future. To measure the thermal or photovoltaic systems a solar irradiation database is necessary. Brazil still has a reduced number of meteorological stations that provide frequency tests, as an alternative to the radio data platform, with reanalysis systems, quite significant. ERA-Interim is a global fire reanalysis by the European Center for Medium-Range Weather Forecasts (ECMWF). The data assimilation system used for the production of ERA-Interim is based on a 2006 version of the IFS (Cy31r2). The system includes a 4-dimensional variable analysis (4D-Var) with a 12-hour analysis window. The spatial resolution of the dataset is approximately 80 km at 60 vertical levels from the surface to 0.1 hPa. This work aims to make a comparative analysis between the ERA-Interim data and the data observed in the Solarimmetric Atlas of the State of Rio Grande do Sul, to verify its applicability in the absence of an observed data network. The analysis of the results obtained for a study region as an alternative to the energy potential of a given region.

Keywords: energy potential, reanalyses, renewable energy, solar radiation

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Authors: Mensah-Akoto Julius, Kenichi Matsui

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This paper examines the impact of COVID-19 on waste management workers in Ghana. A questionnaire survey was conducted among 60 waste management workers in Accra metropolis, the capital region of Ghana, to understand the impact of the COVID-19 pandemic on waste generation, workers’ safety in collecting solid waste, and service delivery. To find out correlations between the pandemic and safety of waste management workers, a regression analysis was used. Regarding waste generation, the results show the pandemic led to the highest annual per capita solid waste generation, or 3,390 tons, in 2020. Regarding the safety of workers, the regression analysis shows a significant and inverse association between COVID-19 and waste management services. This means that contaminated wastes may infect field workers with COVID-19 due to their direct exposure. A rise in new infection cases would have a negative impact on the safety and service delivery of the workers. The result also shows that an increase in economic activities negatively impacts waste management workers. The analysis, however, finds no statistical relationship between workers’ service deliveries and employees’ salaries. The study then discusses how municipal waste management authorities can ensure safe and effective waste collection during the pandemic.

Keywords: Covid-19, waste management worker, waste collection, Ghana

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Authors: Howaidi M. Al-Otaibi, Abdulrahman S. Al-Suhaibani, Hamad A. Alsoliman

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Fibers are extensively used in civil engineering applications for many years. In this study, empty fruit bunch of date palm trees were used to produce cellulose fiber that were used as additives in the asphalt binder. Two sizes (coarse and fine) of cellulose fibers were pre-blended in PG64-22 binder with various contents of 1.5%, 3%, 4.5%, 6%, and 7.5% by weight of asphalt binder. The physical and rheological properties of fiber modified asphalt binders were tested by using conventional tests such as penetration, softening point and viscosity; and SHRP test such as dynamic shear rheometer. The results indicated that the fiber modified asphalt binders were higher in softening point, viscosity, and complex shear modulus, and lower in penetration compared to pure asphalt. The fiber modified binders showed an improvement in rheological properties since it was possible to raise the control binder (pure asphalt) PG from 64 to 70 by adding 6% (by weight) of either fine or coarse fibers. Such improvement in stiffness of fiber modified binder is expected to improve pavement resistance to rutting.

Keywords: cellulose date palm fiber, fiber modified asphalt, physical properties, rheological properties

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Authors: Pataraporn Kheawwan

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Preceptorship represents an important aspect in new nurse orientation. However, there was no formal preceptor training program developed for nurse preceptor in Thailand. The purposes of this study were to develop and evaluate formal preceptor training program for nurse preceptors in King Chulalongkorn Memorial Hospital, Thailand. A research and development study design was utilized in this study. Participants were 37 nurse preceptors. The program contents were delivered by e-learning material, class lecture, group discussion followed by simulation training. Knowledge of the participants was assessed pre and post program. Skill and critical thinking were assessed using Preceptor Skill and Decision Making Evaluation form at the end of program. Statistical significant difference in knowledge regarding preceptor role and coaching strategies between pre and post program were found. All participants had satisfied skill and decision making score after completed the program. Most of participants perceived benefits of preceptor training course. In conclusion, The results of this study reveal that the newly developed preceptorship course is an effective formal training course for nurse preceptors.

Keywords: preceptor, preceptorship, new nurse, clinical education

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Authors: Mohammed Bakhit Kashoob, Mohammed Salim Al-Maashani, Ahmed Abdullah Al-Marhoon

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Fatalities of Road Traffic Crashes (RTCs) on rural roads are usually higher than that on urban roads. The likelihood of traffic accidents may increase with the presence of factors that are associated with the rural type of community such as long-distance, road type, road geometry (e.g., curves and steepens), poor lighting, terrain, obstacles (e.g., animals crossing, boulders or tree branches), heavy truck traffic, weather conditions, and road flaws. Most of these factors are present on the rural roads of Oman. As many cities in Oman are surrounded by mountains and connected by rural roads, this is of great concern. In this paper, the causes of traffic crashes on rural roads in Oman are analyzed. The fatality rate of traffic deaths on rural roads is compared with the fatality rate on urban roads for different regions in Oman. Statistical data and police reports show that the leading cause of RTCs and deaths on rural roads is vehicle speeding, especially on long-distance roads. It is shown that crashes on rural roads result in higher fatalities than crashes on urban roads. In comparison to speed, the numbers of RTCs and deaths that resulted from other causes are small.

Keywords: causes of traffic crashes, road safety, road traffic crash, rural roads

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Authors: Clarissa L. de Araujo, Kátia N. Suzuki, Wilson T. V. Machado, Luis F. Bellido, Alfredo V.B. Bellido

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This study aims at contributing to the characterization of the process of biological incorporation of chromium by two benthonic species, the macroalgae Ulva sp. and the aquatic macrophyte Ruppia maritima, to subsidize future activities of monitoring the contamination of aquatic biota. This study is based on laboratory experiments to characterize the incorporation kinetics of the radiotracer ⁵¹Cr in two oxidation states (III and VI), under different salinities (7, 15, and 21 ‰). Samples of two benthonic species were collected on the margins of Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil), acclimated in the laboratory and subsequently subjected to experiments. In tests with 51Cr (III and IV), it was observed that accumulation of the metal in Ulva sp. has inverse relationship with salinity, while for R. maritima, the maximum accumulation occurs in salinity 21‰. In experiments with Cr(III), increases in the uptake of ion by both species were verified. The activity of Cr(III) was up to 19 times greater than the Cr(VI). As regards the potential for accumulation of metals, a better sensitivity of Ulva sp. for any chromium tri or hexavalent forms was verified, while for the Cr(VI) it will require low salinities and longer exposure (>24h). For R. maritima, the results showed the uptake of Cr(VI) increase along with time (>20h), because this species is more resistant for the hexavalent form and useful for any salinity as well.

Keywords: chromium, Cr-51, macroalgae, macrophyte, uptake

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Authors: Mohammad Hadi Mahmoodi, Mojtaba Farahani

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The present study aimed at investigating whether reflective thinking differentiates Iranian EFL learners regarding language learning strategy use, beliefs about language learning and teaching, and L2 proficiency. To this end, the researcher adopted a mixed method approach. First, 94 EFL learners were asked to complete Reflective Thinking Questionnaire (Kember et al., 2000), Beliefs about Language Learning and Teaching Inventory (Horwitz, 1985), Strategy Inventory for Language Learning (Oxford, 1990), and Oxford Quick Placement Test. The results of three separate one-way ANOVAs indicated that reflective thinking significantly differentiates Iranian EFL learners concerning: (a)language learning strategy use, (b) beliefs about language learning and teaching, and (c) general language proficiency. Furthermore, to see where the differences lay, three separate post-hoc Tukey tests were run the results of which showed that learners with different levels of reflectivity (high, mid, and low) were significantly different from each other in all three dependent variables. Finally, to increase the validity of the findings thirty of the participants were interviewed and the results were analyzed through template organizing style method (Crabtree & Miller, 1999). The results of the interview analysis supported the results of quantitative data analysis.

Keywords: reflective thinking, language learning strategy use, beliefs toward language learning and teaching

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Authors: Viloria Marin Hermes, Paredes Santiago Maritza, Viloria Paredes Jonathan

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The aim of this study is to assess the prevalence of Burnout syndrome in a sample of 600 professors at the University of Guayaquil (Ecuador) using the Maslach Burnout Inventory (M.B.I.). In addition, assessment was made of the effects on health from professional burnout using the General Health Questionnaire (G.H.Q.-28), and the influence of Emotional Intelligence on prevention of its symptoms using the Spanish version of the Trait Meta-Mood Scale (T.M.M.S.-24). After confirmation of the underlying factor structure, the three measurement tools showed high levels of internal consistency, and specific cut-off points were proposed for the group of Latin American academics in the M.B.I. Statistical analysis showed the syndrome is present extensively, particularly on medium levels, with notably low scores given for Professional Self-Esteem. The application of Canonical Correspondence Analysis revealed that low levels of self-esteem are related to depression, with a lack of personal resources related to anxiety and insomnia, whereas the ability to perceive and control emotions and feelings improves perceptions of professional effectiveness and performance.

Keywords: burnout, academics, emotional intelligence, general health, canonical correspondence analysis

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Authors: Dalila Hammiche, Lisa Klaai, Amar Boukerrou

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Following this trend, natural fiber reinforcements have been gaining importance in the composites sector. The effectiveness of natural fiber–reinforced PLA composite as an alternative material to substitute the non-renewable petroleum-based materials has been examined by researchers. In this study, we investigated the physicochemical, particle size and distribution, and thermal behavior of prickly pear seed flour (PPSF). Then, composites were manufactured with 20% in PPSF. Thermal, morphological, and mechanical properties have been studied, and water absorption tests as well. The characterization of this fiber has shown that cellulose is the majority constituent (30%), followed by hemicellulose (27%). To improve the fiber-matrix adhesion, the PPS was chemically treated with alkali treatment. The addition of PPSF decreases the thermal properties, and the study of the mechanical properties showed that the increase in the fiber content from 0 to 20% increased Young’s modulus. According to the results, the mechanical and thermal behaviors of composites are improved after fiber treatment. However, there is an increase in water absorption of composites compared to the PLA matrix. The moisture sensitivity of natural fiber composites limits their use in structural applications. Degradation of the fiber-matrix interface is likely to occur when the material is subjected to variable moisture conditions.

Keywords: biopolymer, composites, alcali treatment, mechanical properties

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Authors: H. Zou, B. Wang

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Thermal distortion of the machine tool plays a critical role in its machining accuracy. This study investigates the thermal performance of a high-precision machine frame with future-oriented mineral casting components. A thermo-mechanical finite element model (FEM) was established to evaluate the thermal behavior of the frame under environmental thermal fluctuations. The validity of the presented FEM model was confirmed experimentally by a series of laser interferometer tests. Good agreement between numerical and experimental results demonstrates that the proposed model can accurately predict the thermal deformation of the frame with thermo-mechanical coupling effect. The results also show that keeping the workshop in thermally stable conditions is crucial for improving the machine accuracy of the system with large scale components. The goal of this paper is to investigate the feasibility of innovative mineral casting material applied in high-precision drilling machine and to provide a strategy for machine tool industry seeking a perfect substitute for classic frame materials such as cast iron and granite.

Keywords: thermo-mechanical model, finite element method, laser interferometer, mineral casting frame

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Authors: Soheil Roumi, Fan Zhang, Rodney Stewart

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Indoor environmental quality (IEQ) indexes represented the suitability of a place to study, work, and live. Many indexes have been introduced based on the physical measurement or occupant surveys in commercial buildings. The earlier studies did not elaborate on the relationship between energy consumption and IEQ in office buildings. Such a relationship can provide a comprehensive overview of the building's performance. Also, it would find the potential of already constructed buildings under the upcoming climate change. A commercial building in southeast Queensland, Australia, was evaluated in this study. Physical measurements of IEQ and Energy areconducted, and their relationship will be determined using statistical analysis. The case study building is modelled in TRNSys software, and it will be validatedusingthe actual building's BMS data. Then, the modelled buildingwill be simulated by predicted weather data developed by the commonwealth scientific and industrial research organisation of Australia to investigate the occupant resilience and energy consumption. Finally, recommendations will be presented to consume less energy while providinga proper indoor environment for office occupants.

Keywords: IEQ, office buildings, thermal comfort, occupant resilience

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Authors: Jaworski Mariusz, Owczarek Krzysztof, Adamus Mirosława

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Binge eating disorder (BED) is one of the three main eating disorders, beside anorexia and bulimia nervosa. BED is characterized by a loss of control over the quantity of food consumed and the lack of the compensatory behaviors, such as induced vomiting or purging. Studies highlight that certain personality traits may contribute to the severity of symptoms in the ED. The aim of this study is to analyze the relationship between psychological variables (Impulsivity and Urgency) and Nutritional restrictions in BED. The study included two groups. The first group consisted of 35 women with BED aged 18 to 28. The control group - 35 women without ED aged 18 to 28. ED-1 questionnaire was used in a study to assess the severity of impulsivity, urgency and nutritional restrictions. The obtained data were standardized. Statistical analyzes were performed using SPSS 21 software. The severity of impulsivity was higher in patients with BED than the control group. The relation between impulsivity and nutritional restrictions in BED was observed, only taking into consideration the relationship of these variables with the level of urgency. However, if the severity of urgency in this relationship is skipped, the relationship between impulsivity and nutritional restrictions will not occur. Impulsivity has a negative relationship with the level of urgency. This study suggests the need to analyze the interaction between impulsivity and urgency, and their relationship with dietary behavior in BED, especially nutritional restrictions. Analysis of single isolated features may give erroneous results.

Keywords: binge eating disorder, impulsivity, nutritional restrictions, urgency

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Authors: Nitu Marilena Cristina

Abstract:

Decentralization of the education system is an educational policy option necessary from the perspective of democratizing internal life and streamlining service administration public. The experience of recent years has shown that decisions taken at central level do not to take into account all situations and especially all the specific needs and interests of the various institutions and individuals. A democratic society implies that the decision-making process is brought closer to the place of application, allowing citizens to take part in the decision-making that affects them directly or indirectly. Essentially decentralization of pre-university education is the transfer of authority, responsibility and resources in decision-making and general management, and financially to the educational units and the local community. This creates a frame of an effective collaboration between school and community. Modern theories on the leadership of education advocate the adoption of decentralization measures and participatory strategies. Numerous countries confronted with the educational impasse has appealed to these strategies. Reforming projects have begun application diversified and nuanced social decentralization models according to the specific social and educational situation. Analysis of legal provisions and measures adopted in the framework of the reform process indicates that, at least formally, decentralization is the solution chosen.

Keywords: decentralization, educational, management, reforming

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Authors: Serge B. Provost

Abstract:

Numerous statistical inference and modeling methodologies are based on sample moments rather than the actual observations. A result justifying the validity of this approach is introduced. More specifically, it will be established that given the first n moments of a sample of size n, one can recover the original n sample points. This implies that a sample of size n and its first associated n moments contain precisely the same amount of information. However, it is efficient to make use of a limited number of initial moments as most of the relevant distributional information is included in them. Two types of density estimation techniques that rely on such moments will be discussed. The first one expresses a density estimate as the product of a suitable base density and a polynomial adjustment whose coefficients are determined by equating the moments of the density estimate to the sample moments. The second one assumes that the derivative of the logarithm of a density function can be represented as a rational function. This gives rise to a system of linear equations involving sample moments, the density estimate is then obtained by solving a differential equation. Unlike kernel density estimation, these methodologies are ideally suited to model ‘big data’ as they only require a limited number of moments, irrespective of the sample size. What is more, they produce simple closed form expressions that are amenable to algebraic manipulations. They also turn out to be more accurate as will be shown in several illustrative examples.

Keywords: density estimation, log-density, polynomial adjustments, sample moments

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Authors: Kim Ji-Hyun, Jeon Hye-Seon, Kwon Oh-Yun, Park Eun-Young, Hwang Ui-Jae, Gwak Gyeong-Tae, Yoon Hyeo-Bin

Abstract:

Stress urinary incontinence (SUI), a common women health problem, is an involuntary leakage of urine while sneezing, coughing, or physical exertion caused by insufficient strength of the pelvic floor and sphincter muscles. SUI also leads to decrease in quality of life and limits sexual activities. SUI is related to the increased bladder neck angle, bladder neck movement, funneling index, urethral width, and decreased urethral length. Various pelvic floor muscle electrical stimulation (ES) interventions have been applied to improve the symptoms of the people with SUI. ES activates afferent fibers of pudendal nerve and smoothly induces contractions of the pelvic floor muscles such as striated periurethral muscles and striated pelvic floor muscles. ES via intravaginal electrodes are the most frequently used types of the pelvic floor muscle ES for the female SUI. However, inserted electrode is uncomfortable and it increases the risks of infection. The purpose of this preliminary study was to determine if the 8-week transcutaneous pelvic floor ES would be effective to improve the symptoms and satisfaction of the females with SUI. Easy-K, specially designed ES equipment for the people with SUI, was used in this study. The oval shape stimulator can be placed on a toilet seat, and the surface has invaded electrode fit to contact with the entire vulva area while users are sitting on the stimulator. Five women with SUI were included in this experiment. Prior to the participation, subjects were instructed about procedures and precautions in using the ES. They have used the stimulator once a day for 20 minutes for each session at home. Outcome data was collected 3 times at the baseline, 4 weeks and 8 weeks after the intervention. Intravaginal sonography was used to measure the bladder neck angle, bladder neck movement, funneling index, thickness of an anterior rhabdosphincter and a posterior rhabdosphincter, urethral length, and urethral width. Leavator ani muscle (LAM) contraction strength was assessed by manual palpation according to the oxford scoring system. In addition, incontinence quality of life (IQOL) and female sexual function index (FSFI) questionnaires were used to obtain addition subjective information. Friedman test, a nonparametric statistical test, was used to determine the effectiveness of the ES. The Wilcoxon test was used for the post-hoc analysis and the significance level was set at .05. The bladder neck angle, funneling index and urethral width were significantly decreased after 8-weeks of intervention (p<.05). LAM contraction score, urethral length and anterior and posterior rhabdosphicter thickness were statistically increased by the intervention (p<.05). However, no significant change was found in the bladder neck movement. Although total score of the IQOL did not improve, the score of the ‘avoidance’ subscale of IQOL had significant improved (p<.05). FSFI had statistical difference in FSFI total score and ‘desire’ subscale (p<.05). In conclusion, 8-week use of a transcutaneous ES on peri-vulva area improved dynamic mechanical structures of the pelvic floor musculature as well as IQOL and conjugal relationship.

Keywords: electrical stimulation, Pelvic floor muscle, sonography, stress urinary incontinence, women health

Procedia PDF Downloads 134

Authors: Harish Aryal, Thalia Balderas, Alondra Rodriguez

Abstract:

Radioactivity present in nature possess a major challenge to public health and occupational concerns. Even at low doses, NORM can cause radiation-induced cancers, heritable diseases, genetic defects, etc. There have not been enough radiological studies and consequently, there is a lack of supportive data. In addition, there is no universal medical surveillance program for low-level doses and there is a need for NORM management guidelines for appropriate control. Naturally Occurring Radioactive Material (NORM) is present everywhere during oil/gas exploration. Currently, there is limited data available to quantify radioactivity. This research presents the study of radioactivity in different areas in the United States to be encouraged to be used for further study in Texas or similar areas within the oil and gas industry. Many materials that are found in the oil and gas industry are NORM (Naturally Occurring Radioactive Materials). The NORM is made of various types of materials, including Radium 226, Radium 228, and Radon 222. Efforts to characterize the geographic distribution of NORM have been limited by poor statistical representation in this area of study. In addition, the fate of NORM in the environment has not been fully defined, and few human health risk assessments have been conducted. To further comprehend how to measure radioactivity in oil and gas, it will be essential to understand the amount and type of radioactivity that is wasted on the water and soil of the industry.

Keywords: NORM, radium 226, radon 222, radionuclides, geological formations

Procedia PDF Downloads 60