364 research outputs found
Usability analysis of 3D Maps for Pedestrian Navigation among different demographic profiles
3-Dimensional (3D) maps may provide the users with a more
real-world like view in comparison with the 2-Dimensional (2D) maps. 3D
maps offer more degree of freedom in movement to the users, a first-person
perspective view and other dynamic details such as time of the day, weather
could also be incorporated. This paper demonstrates the evaluation of the
usability of 3D maps for navigation purposes, in several general aspects
including recognizing landmarks and using these visual cues for navigation
among different representative user-groups. The 3D model was designed to
replicate the High Street, Stratford, London, UK. The participants of the
survey were required to explore the model, identify and memorize the
landmarks and form a mental map. They were also asked to reproduce the
route they took in a 2D paper map and answer a questionnaire on their perception of their own cognitive abilities and their response on the performance of the 3D model. The results confirmed that the usability can vary
among users of different demographic profiles – age, gender and language
and familiarity with 3D technologies. It also showed that with some improvements in level of details incorporated in the model and design, 3D
maps could become a useful tool for navigation purposes
Critical States Embedded in the Continuum
We introduce a class of critical states which are embedded in the continuum
(CSC) of one-dimensional optical waveguide array with one non-Hermitian defect.
These states are at the verge of being fractal and have real propagation
constant. They emerge at a phase transition which is driven by the imaginary
refractive index of the defect waveguide and it is accompanied by a mode
segregation which reveals analogies with the Dicke super -radiance. Below this
point the states are extended while above they evolve to exponentially
localized modes. An addition of a background gain or loss can turn these
localized states to bound states in the continuum.Comment: 4.5 pages, 3 figures, 1 page of supplementary material including one
figur
Transport development, intellectual property rights protection and innovation: The case of the Yangtze River Delta Region, China
The links between transport development and economic growth have been widely discussed in the field of transport governance and economics. However, the existing studies have not included an institutional variable when exploring the role of transport development in innovation disparities within a region. In order to fill the research gap, this paper examines whether transport development and the institution of intellectual property rights (IPRs) can assist in understanding disparities between cities in terms of innovation, using the Yangtze River Delta Region (YRDR) as a case study. The impact mechanism is twofold. Firstly, transport development can affect institutions, including IPRs protection, which in turn has an influence on innovation. Secondly, evidence from existing economic literature suggests a link between transport development and innovation through economic agglomeration, production factors and industrial flows. We first employ ordinary least squares (OLS) regression to test the basic associations between transport development and innovation. We then apply two-stage least squares (2SLS) regression analysis to address endogeneity and add a spatial model to examine neighbour effects. The findings show that IPRs protection has a positive effect on patenting and research and development (R&D), while the roles played by transport development stock and density in patenting and R&D are more mixed. Moreover, our findings on neighbour effects show that agglomeration economies exist in the YRDR. These findings have important policy implications regarding urban agglomeration for both the YRDR specifically and China overall
The Impact of Biases in the Crowdsourced Trajectories on the Output of Data Mining Processes
The emergence of the Geoweb has provided an unprecedented capacity for generating and sharing digital content by professional and non- professional participants in the form of crowdsourcing projects, such as OpenStreetMap (OSM) or Wikimapia. Despite the success of such projects, the impacts of the inherent biases within the ‘crowd’ and/or the ‘crowdsourced’ data it produces are not well explored. In this paper we examine the impact of biased trajectory data on the output of spatio-temporal data mining process. To do so, an experiment was conducted. The biases are intentionally added to the input data; i.e. the input trajectories were divided into two sets of training and control datasets but not randomly (as opposed to the data mining procedures). They are divided by time of day and week, weather conditions, contributors’ gender and spatial and temporal density of trajectory in 1km grids. The accuracy of the predictive models are then measured (both for training and control data) and biases gradually moderated to see how the accuracy of the very same model is changing with respect to the biased input data. We show that the same data mining technique yields different results in terms of the nature of the clusters and identified attributes
Experimental study on heat transfer from rectangular fins in combined convection
Combined natural and forced convective heat transfer arise in many transport processes in engineering devices and in nature, which is frequently encountered in industrial and technical processes, including electronic devices cooled by fans, heat exchangers placed in a low-velocity environment, and solar receivers exposed to winds. In this study, the effects of design
parameters have been experimentally investigated for the air-side thermal performance under combined (natural and forced)convection of the rectangular plate heat sinks, and the values of optimum design parameters were sought. Many ideas for improving cooling methods have been proposed, one of which is the heat sink. In this work, the average Nusselt number (Nu) and thermal resistance of a simple base rectangular plate and five vertical rectangular plate heat sinks with different numbers of fins under natural and combined convection were experimentally investigated to obtain the maximum average Nu and minimum thermal resistance for various Reynolds numbers (Re) from 2300 to 40000, Rayleigh numbers (Ra) from 1300000 to 13000000, and Richardson numbers (Ri) from 0.4 to 3. Also, in this experiment, fin spacing (P) was varied from 2.8 mm to 14.6 mm and the dimensionless P/H ratio was varied from 0.1
to 0.49. The flow velocity varied in the range of 2 to 8 m/s under combined convection. Based on the effects of Ri and Re, two empirical equations for natural and also for combined convection heat transfer were derived to calculate the average Nu. The average deviation for these two equations is about 7%.The outcomes of this research can be beneficial for engineers who
work on electronics cooling systems
Immunohistochemistry study on androgen and estrogen receptors of rat seminal vesicle submitted to simultaneous alcohol-nicotine treatment
Objective: Alcohol consumption is habitually accompanied by the use of other psychoactive substances, mostly tobacco. Nicotine and alcohol affect male accessory reproductive glands function. Most studies have been done on pathologic features of prostate, but there has been no systematic study on the seminal vesicle. Therefore, the aim of current study was to investigate the distribution of androgen receptor (AR) and estrogen receptors-beta (ER-β) immune reactivities following long-term treatment of alcohol, nicotine or a combination of both substances. Materials and Methods: In this experimental study, a total of 40 adult Wistar rats, nine weeks of age, were used. Animals were randomly divided into four groups, including: i. Control group receiving normal saline 0.09, ii. Ethanol group receiving ethanol 20 (2 ml/kg, via gavage), iii. Nicotine group receiving nicotine (0.1 mg/kg, subcutaneous injection), and iv. Ethanol-nicotine group receiving simultaneous ethanol 20 (2 ml/kg) and nicotine (0.1 mg/kg) treatment. All treatment lasted for eight weeks. Prior to intracardiac perfusion, blood sample was collected from left ventricle. The seminal vesicles were isolated and processed for paraffn blocking. The sample tissues were then studied for distribution of AR and ER-β immunereactivities using immunohistochemical (IHC) staining method. One way analysis of variance (ANOVA) and Tukey's test were performed for data analysis. A value of P<0.05 was considered signifcant. Results: Our results revealed that the lowest mean number of positive cells belonged to the animals of ethanol-nicotine group that was followed by the ethanol, nicotine, and control groups, respectively. However, there was no signifcant difference regarding serum testosterone level among experimental groups. Conclusion: It was concluded that combination of both ethanol and nicotine may be a crucial factor in the expression levels of AR and ER-β
The Effect of G-ORS Along With Rice Soup in the Treatment of Acute Diarrhea in Children: A Single-Blind Randomized Controlled Trial
Background: The world health organization guidelines for treatment of diarrhea in children emphasize on continued feeding together with prescription of oral rehydration solution (ORS) and supplementary zinc therapy. However, conflicting viewpoints exist regarding the optimal diet and dietary ingredients for children with diarrhea. Moreover, few studies have investigated the effect of rice soup along with ORS in the treatment of this disease.
Objectives: This study aimed to explore effects of simultaneous taking of glucose oral rehydration solution (G-ORS) and rice soup in the treatment of acute diarrhea in 8 to 24-month-old children.
Patients and Methods: This single-blind controlled clinical trial was conducted in the pediatric ward of 22nd of Bahman hospital, Gonabad, Iran between June 2013 and February 2014. Forty children aged 8-24 months with acute diarrhea were randomly assigned into an intervention group (G-ORS plus rice soup group) comprising 20 babies and a control group (G-ORS) of 20 children based on balanced blocking randomization. The variables under investigation were diarrhea duration, patient hospitalization, need for intravenous (IV) fluids and stool output frequency. Data was analyzed using independent samples t and chi-square test.
Results: At the end of study, the time for treating acute watery diarrhea in the intervention and control groups were 21.10 ± 8.81 and 34.55 ± 5.82 hours (P < 0.001) and hospital stay were 34.05 ± 6.62 and 40.20 ± 6.32 hours (P = 0.005). Moreover, stool output frequency were 4.20 ± 0.95 and 8.00 ± 1.37 (P < 0.001) in the first 24 hours, and 2.18 ± 0.60 and 2.80 ± 0.76 (P = 0.03) in the second 24 hours of treatment in intervention and control groups, respectively.
Conclusions: Rice soup regimen was highly effective and inexpensive in the treatment of acute diarrhea in children. Thus, in addition to the common treatment by G-ORS, rice soup can be consumed simultaneously with G-ORS
Association between paraoxonase-1 gene promoter T (-107) C polymorphism and coronary artery disease
Background: Paraoxonase-1(PON1), a high-density lipoprotein (HDL) associated enzyme, is believed to contribute in the pathogenesis of coronary artery disease (CAD). The aim of this study was to evaluate the association of PON1 promoter C (-107)T polymorphism with the extent of coronary artery stenosis in Iranian patients. Methods: The RFLP analysis for determination of the C(-107)T genotype distribution and measurement of serum PON1 activities (Paraoxonase and Arylesterase) were performed in 99 patients. They were undergone coronary angiography to determine the number of stenotic vessels and classified into three groups: single vessel disease (SVD), two vessels disease (2VD) and three vessels disease (3VD). Results: The C(-107)T polymorphism was significantly associated with serum arylesterase activity but not with paraoxonase activity. The CC and TT genotypes distributed inversely in SVD as compared with 3VD group. Moreover, the CC high activity genotype frequency decreased with increase of stenotic vessels in patients. Conclusion: The reduced arylesterase activity as a function from the weak promoter activity increases the stenosis severity, so that, we assume it is one of the progressive factors of atherosclerotic process in stenotic vessels
Ultrasound - guided access during percutaneous nephrolithotomy: Entering desired calyx with appropriate entry site and angle
Objectives: To evaluate the success of ultrasonography directed renal access in entering the target calyx from proper entry site and in the direction of renal pelvis during percutaneous nephrolithotomy (PCNL). Materials and Methods: PCNL cases who were operated on by one fellow from May- June 2014 were included in this study. A vertically placed ultrasound probe on the patient flank in prone position was used to identify the preselected target calyx. Needle was advanced through needle holder and fluoroscopy was used to document the entered calyx, site and angle of entry. Results: Successful entering to the target calyx was achieved in 43 cases (91). Successful entry with appropriate entry site and angle was observed in 34 cases (72). Reasons for failure were minimal hydronephrosis, upper pole access and high lying kidneys. Conclusions: Although it is feasible to access a preselected calyx by ultrasonography guidance during PCNL, but entry to the calyx from the appropriate site and direction is another problem and needs more experience. In cases of minimal hydronephrosis, superior pole access or high lying kidneys, ultrasonography is less successful and should be used with care
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