Search results for: number sense
9732 Non-Invasive Imaging of Tissue Using Near Infrared Radiations
Authors: Ashwani Kumar Aggarwal
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NIR Light is non-ionizing and can pass easily through living tissues such as breast without any harmful effects. Therefore, use of NIR light for imaging the biological tissue and to quantify its optical properties is a good choice over other invasive methods. Optical tomography involves two steps. One is the forward problem and the other is the reconstruction problem. The forward problem consists of finding the measurements of transmitted light through the tissue from source to detector, given the spatial distribution of absorption and scattering properties. The second step is the reconstruction problem. In X-ray tomography, there is standard method for reconstruction called filtered back projection method or the algebraic reconstruction methods. But this method cannot be applied as such, in optical tomography due to highly scattering nature of biological tissue. A hybrid algorithm for reconstruction has been implemented in this work which takes into account the highly scattered path taken by photons while back projecting the forward data obtained during Monte Carlo simulation. The reconstructed image suffers from blurring due to point spread function. This blurred reconstructed image has been enhanced using a digital filter which is optimal in mean square sense.Keywords: least-squares optimization, filtering, tomography, laser interaction, light scattering
Procedia PDF Downloads 3169731 Flow-Control Effectiveness of Convergent Surface Indentations on an Aerofoil at Low Reynolds Numbers
Authors: Neel K. Shah
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Passive flow control on aerofoils has largely been achieved through the use of protrusions such as vane-type vortex generators. Consequently, innovative flow-control concepts should be explored in an effort to improve current component performance. Therefore, experimental research has been performed at The University of Manchester to evaluate the flow-control effectiveness of a vortex generator made in the form of a surface indentation. The surface indentation has a trapezoidal planform. A spanwise array of indentations has been applied in a convergent orientation around the maximum-thickness location of the upper surface of a NACA-0015 aerofoil. The aerofoil has been tested in a two-dimensional set-up in a low-speed wind tunnel at an angle of attack (AoA) of 3° and a chord-based Reynolds number (Re) of ~2.7 x 105. The baseline model has been found to suffer from a laminar separation bubble at low AoA. The application of the indentations at 3° AoA has considerably shortened the separation bubble. The indentations achieve this by shedding up-flow pairs of streamwise vortices. Despite the considerable reduction in bubble length, the increase in leading-edge suction due to the shorter bubble is limited by the removal of surface curvature and blockage (increase in surface pressure) caused locally by the convergent indentations. Furthermore, the up-flow region of the vortices, which locally weakens the pressure recovery around the trailing edge of the aerofoil by thickening the boundary layer, also contributes to this limitation. Due to the conflicting effects of the indentations, the changes in the pressure-lift and pressure-drag coefficients, i.e., cl,p and cd,p, are small. Nevertheless, the indentations have improved cl,p and cd,p beyond the uncertainty range, i.e., by ~1.30% and ~0.30%, respectively, at 3° AoA. The wake measurements show that turbulence intensity and Reynolds stresses have considerably increased in the indented case, thus implying that the indentations increase the viscous drag on the model. In summary, the convergent indentations are able to reduce the size of the laminar separation bubble, but conversely, they are not highly effective in reducing cd,p at the tested Reynolds number.Keywords: aerofoil flow control, laminar separation bubbles, low Reynolds-number flows, surface indentations
Procedia PDF Downloads 2269730 Influence of Shield Positions on Thermo/Fluid Performance of Pin Fin Heat Sink
Authors: Ramy H. Mohammed
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In heat sinks, the flow within the core exhibits separation and hence does not lend itself to simple analytical boundary layer or duct flow analysis of the wall friction. In this paper, I present some findings from an experimental and numerical study aimed to obtain physical insight into the influence of the presence of the shield and its position on the hydraulic and thermal performance of square pin fin heat sink without top by-pass. The variations of the Nusselt number and friction factor are obtained under varied parameters, such as the Reynolds number and the shield position. The numerical code is validated by comparing the numerical results with the available experimental data. It is shown that, there is a good agreement between the temperature predictions based on the model and the experimental data. Results show that, as the presence of the shield, the heat transfer of fin array is enhanced and the flow resistance increased. The surface temperature distribution of the heat sink base is more uniform when the dimensionless shield position equals to 1/3 or 2/3. The comprehensive performance evaluation approach based on identical pumping power criteria is adopted and shows that the optimum shield position is at x/l=0.43 where energy is saved.Keywords: shield, fin array, performance evaluation, heat transfer, energy
Procedia PDF Downloads 3069729 Promoting Stem Education and a Cosmic Perspective by Using 21st Century Science of Learning
Authors: Rohan Roberts
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The purpose of this project was to collaborate with a group of high-functioning, more-able students (aged 15-18) to promote STEM Education and a love for science by bringing a cosmic perspective into the classroom and high school environment. This was done using 21st century science of learning, a focus on the latest research on Neuroeducation, and modern pedagogical methods based on Howard Gardner's theory of Multiple Intelligences, Bill Lucas’ theory of New Smarts, and Sir Ken Robinson’s recommendations on encouraging creativity. The result was an increased sense of passion, excitement, and wonder about science in general, and about the marvels of space and the universe in particular. In addition to numerous unique and innovative science-based initiatives, clubs, workshops, and science trips, this project also saw a marked rise in student-teacher collaboration in science learning and in student engagement with the general public through the press, social media, and community-based initiatives. This paper also outlines the practical impact that bringing a cosmic perspective into the classroom has had on the lives, interests, and future career prospects of the students involved in this endeavour.Keywords: cosmic perspective, gifted and talented, neuro-education, STEM education
Procedia PDF Downloads 3349728 Management of Severe Asthma with Omalizumab in United Arab Emirates
Authors: Shanza Akram, Samir Salah, Imran Saleem, Jassim Abdou, Ashraf Al Zaabi
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Estimated prevalence of asthma in UAE is around 10% (900,000 people). Patients with persistent symptoms despite using high dose ICS plus a second controller +/- Oral steroids are considered to have severe asthma. Omalizumab (Xolair) is an anti-IgE monoclonal antibody approved as add-on therapy for severe allergic asthma. The objective of our study was to obtain baseline characteristics of our local cohort, to determine the efficacy of omalizumab based on clinical outcomes pre and post 52 weeks of treatment and to assess safety and tolerability. Medical records of patients receiving omalizumab therapy for asthma at Zayed Military Hospital, Abu Dhabi were retrospectively reviewed. Patients fulfilling the criteria for severe allergic asthma as per GINA guidelines were included. Asthma control over 12 months pre and post omalizumab were analyzed by taking into account the number of exacerbations, hospitalizations, maintenance of medication dosages, the need for reliever therapy and PFT’s. 21 patients (5 females) with mean age 41 years were included. The mean duration of therapy was 22 months. 19 (91%) patients had Allergic Rhinitis/Sinusitis. Mean serum total IgE level was 648 IU/ml (65-1859). 11 (52%) patients were on oral maintenance steroids pre-treatment. 7 patients managed to stop steroids on treatment while 4 were able to decrease the dosage. Mean exacerbation rate decreased from 5 per year pre-treatment to 1.36 while on treatment. The number of hospitalizations decreased from a mean of 2 per year to 0.9 per year. Reliever inhaler usage decreased from mean of 40 to 15 puffs per week.2 patients discontinued therapy, 1 due to lack of benefit (2 doses) and 2nd due to severe persistent side effects. Patient compliance was poor in some cases. Treatment with omalizumab reduced the number of exacerbations, hospitalizations, maintenance and reliever medications, and is generally well tolerated. Our results show that there is room for improved documentation in terms of symptom recording and use of rescue medication at our institution. There is also need for better patient education and counseling in order to improve compliance.Keywords: asthma, exacerbations, omalizumab, IgE
Procedia PDF Downloads 3719727 Beneath the Leisurely Surface: An Analysis of the Piano Lesson Frenzy among Chinese Middle-Class Parents
Authors: Yijie Wang, Tianyue Wang
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In the past two decades, there has been a great ‘piano lesson frenzy’ among Chinese middle-class families, with a large number of parents adding piano training to children’s extra-curriculum lists. Superficially, the frenzy reflects a rather ‘leisurely’ attitude: parents typically claim that pianos lessons are ‘just for fun’ and will hopefully render children’s life more exciting. However, a closer scrutiny reveals that there is great social-status anxiety hidden beneath this ‘leisurely’ surface. Based on pre-interviews of six Chinese middle-class parents who have enthusiastically signed their children up for piano lessons, several tentative analysis are made: 1. Owing to a series of historical and social factors, the Chinese middle-class have yet to establish their cultural norms in the past few decades, resulting in great confusion concerning how to cultivate cultural tastes in their offspring. And partly due to the fact that the middle-class status of the past Chinese generation is mostly self-acquired rather than inherited, parents are much less confident about their cultural resources—which require long-time accumulation—than material ones. Both factors combine to lead to a sort of blind, overcompensating enthusiasm in culture-related education, and the piano frenzy is but a demonstration. 2. The piano has been chosen to be the object of the frenzy partly because of its inherent characteristics as well as socially-constructed ones. Costly, large in size, imported from another culture and so forth, the piano has acquired the meaning of being exclusive, high-end and exotic, which renders it a token of top-tier status among Chinese people, and piano lessons for offspring have therefore become parents’ paths towards a kind of ‘symbolic elevation’. A child playing piano is an exhibition as well as psychological assurance of the families’ middle-class status. 3. A closer look at children’s piano training process reveals that there is much more anxiety than leisurely elements involved. Despite parents’ claim that ‘piano is mainly for kids to have fun,’ the whole process is evidently of a rather ‘ascetic’ nature, with the demands of diligence and senses of time urgency throughout, and techniques rather than flair or styles are emphasized. This either means that the apparent ‘piano-for-fun’ stance is unauthentic and is only other motives in disguise, or that the Chinese middle-class parents are not yet capable of shaking off the sense of anxiety even if they sincerely intend to. 4. When viewed in relation to Chinese formal school system as well as the job market at large, it can be said that by signing children up for piano lessons, parents are consciously or unconsciously seeking to prepare for, or reduce the risks of, their children’s future social mobility. In face of possible failures in the highly-crucial, highly-competitive formal school system, piano-playing as an extra-curriculum activity may be conveniently transferred into an alternative career path. Besides, in contemporary China, as the occupational structure goes through change, and the school-related certificates decline in value, aspects such as a person’s overall deportment, which can be gained or proved by piano-learning, have been gaining in significance.Keywords: extra-curriculum activities, middle class, piano lesson frenzy, status anxiety
Procedia PDF Downloads 2459726 Battling with Patriarchy: Political Sexuality and Gender Democracy in Nigeria
Authors: Lenshie, Nsemba Edward
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This paper examines political sexuality as an identity construct, which imparts on democratic practices globally. The manifestation of political sexuality reflect on the dynamics of social, economic, cultural and political relations among different gender affecting a number of issues, such as the questions of citizenship, poverty alleviation, property rights, ownership and inheritance, rights to sexual consent, polygamous marriage, governance and representation among other issues. This paper is concerned with the aspect of political participation among different genders in Nigeria. This paper posit that political sexuality is an outcome of ‘sexuality differences’, which seeks to glorify and gratify the superiority of a particular sexuality over another. Political sexuality, therefore, motivate and exacerbate socio-cultural, economic, and political struggles among different sexualities. The paper asserts further that majority of women have been discriminated, sexually harassed, and are often denied certain rights and privileges in Nigeria. A few number of women who have found themselves at the corridors of government have used the Beijing protocol on Women to demand for ‘affirmative action’ to expand their political space. It contends that the ‘affirmative action’ in Nigeria is far from achieving it throughout the country. The paper conclude that women require more than just a ‘self-rediscovery’ to assertively demand for a more and proper inclusion in Nigeria’s democratic process.Keywords: gender democracy, identity, politics, political sexuality
Procedia PDF Downloads 4379725 Aggregation of Butanediyl-1,4-Bis(Tetradecyldimethylammonium Bromide) (14–4–14) Gemini Surfactants in Presence of Ethylene Glycol and Propylene Glycol
Authors: P. Ajmal Koya, Tariq Ahmad Wagay, K. Ismail
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One of the fundamental property of surfactant molecules are their ability to aggregate in water or binary mixtures of water and organic solvents as an effort to minimize their unfavourable interaction with the medium. In this work, influence two co-solvents (ethylene glycol (EG) and propylene glycol (PG)) on the aggregation properties of a cationic gemini surfactant, butanediyl-1,4-bis(tetradecyldimethylammonium bromide) (14–4–14), has been studied by conductance and steady state fluorescence at 298 K. The weight percentage of two co-solvents varied in between 0 and 50 % at an interval of 5 % up to 20 % and then 10 % up to 50 %. It was found that micellization process is delayed by the inclusion of both the co-solvents; consequently, a progressive increase was observed in critical micelle concentration (cmc) and Gibbs free energy of micellization (∆G0m), whereas a rough increase was observed in the values of degree of counter ion dissociation (α) and a decrease was obtained in values of average aggregation number (Nagg) and Stern-Volmer constant (KSV). At low weight percentage (up to 15 %) of co-solvents, 14–4–14 geminis were found to be almost equally prone to micellization both in EG–water (EG–WR) and in PG–water (PG–WR) mixed media while at high weight percentages they are more prone to micellization in EG–WR than in PG–WR mixed media.Keywords: aggregation number, gemini surfactant, micellization, non aqueous solvent
Procedia PDF Downloads 3259724 Development of DNA Fingerprints in Selected Medicinal Plants of India
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Conventionally, morphological descriptors are routinely used for establishing the identity of varieties. But these morphological descriptors suffer from many drawbacks such as influence of environment on trait expression, epistatic interactions, pleiotrophic effects etc. Furthermore, the paucity of a sufficient number of these descriptors for unequivocal identification of increasing number of reference collection varieties enforces to look for alternatives. Therefore, DNA based finger-print based techniques were selected to define the systematic position of the selected medicinal plants like Plumbago zeylanica, Desmodium gangeticum, Uraria picta. DNA fingerprinting of herbal plants can be useful in authenticating the various claims of medical uses related to the plants, in germplasm characterization and conservation. In plants it has not only helped in identifying species but also in defining a new realm in plant genomics, plant breeding and in conserving the biodiversity. With world paving way for developments in biotechnology, DNA fingerprinting promises a very powerful tool in our future endeavors. Data will be presented on the development of microsatellite markers (SSR) used to fingerprint, characterize, and assess genetic diversity among 12 accessions of both Plumbago zeylanica, 4 accessions of Desmodium gengaticum, 4 accessions of Uraria Picta.Keywords: Plumbago zeylanica, Desmodium gangeticum, Uraria picta, microsaetllite markers
Procedia PDF Downloads 2169723 A Study of the Views of Information Technologies Teachers regarding In-Service Training
Authors: Halit Arslan, Ismail Sahin, Ahmet Oguz Akturk, Ismail Celik
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Today, the means of following the developments in the area of science and technology is to keep up with the pace of the advancements in this area. As is in every profession, apart from their personal efforts, the training of teachers in the period after they start their careers is only possible through in-service training. The aim of the present study is to determine the views of Information Technologies (IT) teachers regarding the in-service training courses organized by the Ministry of National Education. In this study, in which quantitative research methods and techniques were employed, the views of 196 IT teachers were collected by using the “Views on In-service Training” questionnaire developed by the authors of the paper. Independent groups t-test was used to determine whether the views of IT teachers regarding in-service training differed depending on gender, age and professional seniority. One-way analysis of variance (ANOVA) was used to investigate whether the views of IT teachers regarding in-service training differed depending on the number of in-service training courses they joined and the type of in-service training course they wanted to take. According to the findings obtained in the study, the views of IT teachers on in-service training did not show a significant difference depending on gender and age, whereas those views differed depending on professional seniority, the number of in-service training courses they joined and the type of in-service training course they wanted to take.Keywords: in-service training, IT teachers, professional development, personal development
Procedia PDF Downloads 4179722 Visible Expression of Social Identity: The Clothing and Fashion
Authors: Nihan Akdemir
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Clothes are more than a piece of fabric, and the most visible material item of the fashion symbol is the garment, which carries multiple and various meanings. The dynamism of the clothing symbol can carry open or closed codes depending on culture, gender, and social location. And each one can be the expression of social identity over ethnicity, religious beliefs, age, education and social class. Through observation of clothing styles over these items, the assumptions could be made about a person’s identity. A distinctive and typical style, form or character of the clothing such as ‘zoot suits’, ‘ao dai’, removes the garment from functional and ordinary element to the symbolic area. Clothing is an 'identification' tool that functions in determining the symbolic boundaries between people in a sense. And this paper includes the investigation of the relation between social identity and clothing and also fashion. And this relationship has been taken into consideration over the visual expression because even during the ancient times, the clothes were the basic and simple way of representing the identity and social classes. The visible expression of identity over clothing from Ancient Egypt to today’s clothing and fashion has been researched in this article. And all these items have been explained with visual images and supported by the literature investigations. Then the results have shown that every piece of clothing from fabric to coloring have visual significations about social identity.Keywords: social identity, clothing, fashion, visual expression, visual signification
Procedia PDF Downloads 6179721 NABERS Indoor Environment - a Rating Tool to Benchmark the IEQ of Australian Office Commercial Buildings
Authors: Kazi Hossain
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The National Australian Built Environment Rating System (NABERS) is the key industry standard for measuring and benchmarking environmental performance of existing buildings in Australia. Developed and run by the New South Wales government, NABERS measures the operational efficiency of different types of buildings by using a set of tools that provide an easy to understand graphical rating outcome ranged from 0 to 6 stars. This set of tools also include a tool called NABERS IE which enables tenants or building managers to benchmark their buildings indoor environment quality against the national market. Launched in 2009, the number NABERS IE ratings have steadily increased from 10 certified ratings in 2011 to 43 in 2013. However there is a massive uptake of over 50 ratings alone in 2014 making the number of ratings to reach over 100. This paper outlines the methodology used to create this tool, a statistical overview of the tool, and the driving factor that motivates the building owners and managers to use this tool every year to rate their buildings.Keywords: Acoustic comfort, Indoor air quality, Indoor Environment, NABERS, National Australian Built Environment Rating System, Performance rating, Rating System, Thermal comfort, Ventilation effectiveness, Visual comfort.
Procedia PDF Downloads 5629720 Improvement of the Q-System Using the Rock Engineering System: A Case Study of Water Conveyor Tunnel of Azad Dam
Authors: Sahand Golmohammadi, Sana Hosseini Shirazi
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Because the status and mechanical parameters of discontinuities in the rock mass are included in the calculations, various methods of rock engineering classification are often used as a starting point for the design of different types of structures. The Q-system is one of the most frequently used methods for stability analysis and determination of support systems of underground structures in rock, including tunnel. In this method, six main parameters of the rock mass, namely, the rock quality designation (RQD), joint set number (Jn), joint roughness number (Jr), joint alteration number (Ja), joint water parameter (Jw) and stress reduction factor (SRF) are required. In this regard, in order to achieve a reasonable and optimal design, identifying the effective parameters for the stability of the mentioned structures is one of the most important goals and the most necessary actions in rock engineering. Therefore, it is necessary to study the relationships between the parameters of a system and how they interact with each other and, ultimately, the whole system. In this research, it has attempted to determine the most effective parameters (key parameters) from the six parameters of rock mass in the Q-system using the rock engineering system (RES) method to improve the relationships between the parameters in the calculation of the Q value. The RES system is, in fact, a method by which one can determine the degree of cause and effect of a system's parameters by making an interaction matrix. In this research, the geomechanical data collected from the water conveyor tunnel of Azad Dam were used to make the interaction matrix of the Q-system. For this purpose, instead of using the conventional methods that are always accompanied by defects such as uncertainty, the Q-system interaction matrix is coded using a technique that is actually a statistical analysis of the data and determining the correlation coefficient between them. So, the effect of each parameter on the system is evaluated with greater certainty. The results of this study show that the formed interaction matrix provides a reasonable estimate of the effective parameters in the Q-system. Among the six parameters of the Q-system, the SRF and Jr parameters have the maximum and minimum impact on the system, respectively, and also the RQD and Jw parameters have the maximum and minimum impact on the system, respectively. Therefore, by developing this method, we can obtain a more accurate relation to the rock mass classification by weighting the required parameters in the Q-system.Keywords: Q-system, rock engineering system, statistical analysis, rock mass, tunnel
Procedia PDF Downloads 739719 Re-Stating the Origin of Tetrapod Using Measures of Phylogenetic Support for Phylogenomic Data
Authors: Yunfeng Shan, Xiaoliang Wang, Youjun Zhou
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Whole-genome data from two lungfish species, along with other species, present a valuable opportunity to re-investigate the longstanding debate regarding the evolutionary relationships among tetrapods, lungfishes, and coelacanths. However, the use of bootstrap support has become outdated for large-scale phylogenomic data. Without robust phylogenetic support, the phylogenetic trees become meaningless. Therefore, it is necessary to re-evaluate the phylogenies of tetrapods, lungfishes, and coelacanths using novel measures of phylogenetic support specifically designed for phylogenomic data, as the previous phylogenies were based on 100% bootstrap support. Our findings consistently provide strong evidence favoring lungfish as the closest living relative of tetrapods. This conclusion is based on high internode certainty, relative gene support, and high gene concordance factor. The evidence stems from five previous datasets derived from lungfish transcriptomes. These results yield fresh insights into the three hypotheses regarding the phylogenies of tetrapods, lungfishes, and coelacanths. Importantly, these hypotheses are not mere conjectures but are substantiated by a significant number of genes. Analyzing real biological data further demonstrates that the inclusion of additional taxa leads to more diverse tree topologies. Consequently, gene trees and species trees may not be identical even when whole-genome sequencing data is utilized. However, it is worth noting that many gene trees can accurately reflect the species tree if an appropriate number of taxa, typically ranging from six to ten, are sampled. Therefore, it is crucial to carefully select the number of taxa and an appropriate outgroup, such as slow-evolving species, while excluding fast-evolving taxa as outgroups to mitigate the adverse effects of long-branch attraction and achieve an accurate reconstruction of the species tree. This is particularly important as more whole-genome sequencing data becomes available.Keywords: novel measures of phylogenetic support for phylogenomic data, gene concordance factor confidence, relative gene support, internode certainty, origin of tetrapods
Procedia PDF Downloads 609718 Fault Tolerant and Testable Designs of Reversible Sequential Building Blocks
Authors: Vishal Pareek, Shubham Gupta, Sushil Chandra Jain
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With increasing high-speed computation demand the power consumption, heat dissipation and chip size issues are posing challenges for logic design with conventional technologies. Recovery of bit loss and bit errors is other issues that require reversibility and fault tolerance in the computation. The reversible computing is emerging as an alternative to conventional technologies to overcome the above problems and helpful in a diverse area such as low-power design, nanotechnology, quantum computing. Bit loss issue can be solved through unique input-output mapping which require reversibility and bit error issue require the capability of fault tolerance in design. In order to incorporate reversibility a number of combinational reversible logic based circuits have been developed. However, very few sequential reversible circuits have been reported in the literature. To make the circuit fault tolerant, a number of fault model and test approaches have been proposed for reversible logic. In this paper, we have attempted to incorporate fault tolerance in sequential reversible building blocks such as D flip-flop, T flip-flop, JK flip-flop, R-S flip-flop, Master-Slave D flip-flop, and double edge triggered D flip-flop by making them parity preserving. The importance of this proposed work lies in the fact that it provides the design of reversible sequential circuits completely testable for any stuck-at fault and single bit fault. In our opinion our design of reversible building blocks is superior to existing designs in term of quantum cost, hardware complexity, constant input, garbage output, number of gates and design of online testable D flip-flop have been proposed for the first time. We hope our work can be extended for building complex reversible sequential circuits.Keywords: parity preserving gate, quantum computing, fault tolerance, flip-flop, sequential reversible logic
Procedia PDF Downloads 5459717 CFD simulation of Near Wall Turbulence and Heat Transfer of Molten Salts
Authors: C. S. Sona, Makrand A. Khanwale, Channamallikarjun S. Mathpati
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New generation nuclear power plants are currently being developed to be highly economical, to be passive safe, to produce hydrogen. An important feature of these reactors will be the use of coolants at temperature higher than that being used in current nuclear reactors. The molten fluoride salt with a eutectic composition of 46.5% LiF - 11.5% NaF - 42% KF (mol %) commonly known as FLiNaK is a leading candidate for heat transfer coolant for these nuclear reactors. CFD simulations were carried out using large eddy simulations to investigate the flow characteristics of molten FLiNaK at 850°C at a Reynolds number of 10,500 in a cylindrical pipe. Simulation results have been validated with the help of mean velocity profile using direct numerical simulation data. Transient velocity information was used to identify and characterise turbulent structures which are important for transfer of heat across solid-fluid interface. A wavelet transform based methodology called wavelet transform modulus maxima was used to identify and characterise the singularities. This analysis was also used for flow visualisation, and also to calculate the heat transfer coefficient using small eddy model. The predicted Nusselt number showed good agreement with the available experimental data.Keywords: FLiNaK, heat transfer, molten salt, turbulent structures
Procedia PDF Downloads 4499716 Describing Cognitive Decline in Alzheimer's Disease via a Picture Description Writing Task
Authors: Marielle Leijten, Catherine Meulemans, Sven De Maeyer, Luuk Van Waes
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For the diagnosis of Alzheimer's disease (AD), a large variety of neuropsychological tests are available. In some of these tests, linguistic processing - both oral and written - is an important factor. Language disturbances might serve as a strong indicator for an underlying neurodegenerative disorder like AD. However, the current diagnostic instruments for language assessment mainly focus on product measures, such as text length or number of errors, ignoring the importance of the process that leads to written or spoken language production. In this study, it is our aim to describe and test differences between cognitive and impaired elderly on the basis of a selection of writing process variables (inter- and intrapersonal characteristics). These process variables are mainly related to pause times, because the number, length, and location of pauses have proven to be an important indicator of the cognitive complexity of a process. Method: Participants that were enrolled in our research were chosen on the basis of a number of basic criteria necessary to collect reliable writing process data. Furthermore, we opted to match the thirteen cognitively impaired patients (8 MCI and 5 AD) with thirteen cognitively healthy elderly. At the start of the experiment, participants were each given a number of tests, such as the Mini-Mental State Examination test (MMSE), the Geriatric Depression Scale (GDS), the forward and backward digit span and the Edinburgh Handedness Inventory (EHI). Also, a questionnaire was used to collect socio-demographic information (age, gender, eduction) of the subjects as well as more details on their level of computer literacy. The tests and questionnaire were followed by two typing tasks and two picture description tasks. For the typing tasks participants had to copy (type) characters, words and sentences from a screen, whereas the picture description tasks each consisted of an image they had to describe in a few sentences. Both the typing and the picture description tasks were logged with Inputlog, a keystroke logging tool that allows us to log and time stamp keystroke activity to reconstruct and describe text production processes. The main rationale behind keystroke logging is that writing fluency and flow reveal traces of the underlying cognitive processes. This explains the analytical focus on pause (length, number, distribution, location, etc.) and revision (number, type, operation, embeddedness, location, etc.) characteristics. As in speech, pause times are seen as indexical of cognitive effort. Results. Preliminary analysis already showed some promising results concerning pause times before, within and after words. For all variables, mixed effects models were used that included participants as a random effect and MMSE scores, GDS scores and word categories (such as determiners and nouns) as a fixed effect. For pause times before and after words cognitively impaired patients paused longer than healthy elderly. These variables did not show an interaction effect between the group participants (cognitively impaired or healthy elderly) belonged to and word categories. However, pause times within words did show an interaction effect, which indicates pause times within certain word categories differ significantly between patients and healthy elderly.Keywords: Alzheimer's disease, keystroke logging, matching, writing process
Procedia PDF Downloads 3669715 Quadratic Convective Flow of a Micropolar Fluid in a Non-Darcy Porous Medium with Convective Boundary Condition
Authors: Ch. Ramreddy, P. Naveen, D. Srinivasacharya
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The objective of the present study is to investigate the effect of nonlinear temperature and concentration on the mixed convective flow of micropolar fluid over an inclined flat plate in a non-Darcy porous medium in the presence of convective boundary condition. In order to analyze all the essential features, the transformed nonlinear conservation equations are worked out numerically by spectral method. By insisting the comparison between vertical, horizontal and inclined plates, the physical quantities of the flow and its characteristics are exhibited graphically and quantitatively with various parameters. An increase in the coupling number and inclination of angle tend to decrease the skin friction, mass transfer rate and the reverse change is there in wall couple stress and heat transfer rate. The nominal effect on the wall couple stress and skin friction is encountered whereas the significant effect on the local heat and mass transfer rates are found for high enough values of Biot number.Keywords: convective boundary condition, micropolar fluid, non-darcy porous medium, non-linear convection, spectral method
Procedia PDF Downloads 2799714 Relation of Optimal Pilot Offsets in the Shifted Constellation-Based Method for the Detection of Pilot Contamination Attacks
Authors: Dimitriya A. Mihaylova, Zlatka V. Valkova-Jarvis, Georgi L. Iliev
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One possible approach for maintaining the security of communication systems relies on Physical Layer Security mechanisms. However, in wireless time division duplex systems, where uplink and downlink channels are reciprocal, the channel estimate procedure is exposed to attacks known as pilot contamination, with the aim of having an enhanced data signal sent to the malicious user. The Shifted 2-N-PSK method involves two random legitimate pilots in the training phase, each of which belongs to a constellation, shifted from the original N-PSK symbols by certain degrees. In this paper, legitimate pilots’ offset values and their influence on the detection capabilities of the Shifted 2-N-PSK method are investigated. As the implementation of the technique depends on the relation between the shift angles rather than their specific values, the optimal interconnection between the two legitimate constellations is investigated. The results show that no regularity exists in the relation between the pilot contamination attacks (PCA) detection probability and the choice of offset values. Therefore, an adversary who aims to obtain the exact offset values can only employ a brute-force attack but the large number of possible combinations for the shifted constellations makes such a type of attack difficult to successfully mount. For this reason, the number of optimal shift value pairs is also studied for both 100% and 98% probabilities of detecting pilot contamination attacks. Although the Shifted 2-N-PSK method has been broadly studied in different signal-to-noise ratio scenarios, in multi-cell systems the interference from the signals in other cells should be also taken into account. Therefore, the inter-cell interference impact on the performance of the method is investigated by means of a large number of simulations. The results show that the detection probability of the Shifted 2-N-PSK decreases inversely to the signal-to-interference-plus-noise ratio.Keywords: channel estimation, inter-cell interference, pilot contamination attacks, wireless communications
Procedia PDF Downloads 2179713 NO2 Exposure Effect on the Occurrence of Pulmonary Dysfunction the Police Traffic in Jakarta
Authors: Bambang Wispriyono, Satria Pratama, Haryoto Kusnoputranto, Faisal Yunus, Meliana Sari
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Introduction/objective: The impact of the development of motor vehicles is increasing the number of pollutants in the air. One of the substances that cause serious health problems is NO2. The health impacts arising from exposure to NO2 include pulmonary function impairment. The purpose of this study was to determine the relationship of NO2 exposure on the incidence of pulmonary function impairment. Methods: We are using a cross-sectional study design with 110 traffic police who were divided into two groups: exposed (police officers working on the highway) and the unexposed group (police officers working in the office). Election subject convenient sampling carried out in each group to the minimum number of samples met. Results: The results showed that the average NO2 in the exposed group was 18.72 ppb and unexposed group is 4.14 ppb. Pulmonary dysfunction on exposed and unexposed groups showed that FVC (Forced Vital Capacity) value are 88.68 and 90.27. And FEV1 (Forced Expiratory Volume in One) value are 94.9 and 95.16. Some variables like waist circumference, Body Mass Index, Visceral Fat, and Fat has associated with the incidence of Pulmonary Dysfunction (p < 0.05). Conclusion: Health monitoring is needed to decreasing health risk in Policeman.Keywords: NO2, pulmonary dysfunction, police traffic, Jakarta
Procedia PDF Downloads 2579712 Performance and Limitations of Likelihood Based Information Criteria and Leave-One-Out Cross-Validation Approximation Methods
Authors: M. A. C. S. Sampath Fernando, James M. Curran, Renate Meyer
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Model assessment, in the Bayesian context, involves evaluation of the goodness-of-fit and the comparison of several alternative candidate models for predictive accuracy and improvements. In posterior predictive checks, the data simulated under the fitted model is compared with the actual data. Predictive model accuracy is estimated using information criteria such as the Akaike information criterion (AIC), the Bayesian information criterion (BIC), the Deviance information criterion (DIC), and the Watanabe-Akaike information criterion (WAIC). The goal of an information criterion is to obtain an unbiased measure of out-of-sample prediction error. Since posterior checks use the data twice; once for model estimation and once for testing, a bias correction which penalises the model complexity is incorporated in these criteria. Cross-validation (CV) is another method used for examining out-of-sample prediction accuracy. Leave-one-out cross-validation (LOO-CV) is the most computationally expensive variant among the other CV methods, as it fits as many models as the number of observations. Importance sampling (IS), truncated importance sampling (TIS) and Pareto-smoothed importance sampling (PSIS) are generally used as approximations to the exact LOO-CV and utilise the existing MCMC results avoiding expensive computational issues. The reciprocals of the predictive densities calculated over posterior draws for each observation are treated as the raw importance weights. These are in turn used to calculate the approximate LOO-CV of the observation as a weighted average of posterior densities. In IS-LOO, the raw weights are directly used. In contrast, the larger weights are replaced by their modified truncated weights in calculating TIS-LOO and PSIS-LOO. Although, information criteria and LOO-CV are unable to reflect the goodness-of-fit in absolute sense, the differences can be used to measure the relative performance of the models of interest. However, the use of these measures is only valid under specific circumstances. This study has developed 11 models using normal, log-normal, gamma, and student’s t distributions to improve the PCR stutter prediction with forensic data. These models are comprised of four with profile-wide variances, four with locus specific variances, and three which are two-component mixture models. The mean stutter ratio in each model is modeled as a locus specific simple linear regression against a feature of the alleles under study known as the longest uninterrupted sequence (LUS). The use of AIC, BIC, DIC, and WAIC in model comparison has some practical limitations. Even though, IS-LOO, TIS-LOO, and PSIS-LOO are considered to be approximations of the exact LOO-CV, the study observed some drastic deviations in the results. However, there are some interesting relationships among the logarithms of pointwise predictive densities (lppd) calculated under WAIC and the LOO approximation methods. The estimated overall lppd is a relative measure that reflects the overall goodness-of-fit of the model. Parallel log-likelihood profiles for the models conditional on equal posterior variances in lppds were observed. This study illustrates the limitations of the information criteria in practical model comparison problems. In addition, the relationships among LOO-CV approximation methods and WAIC with their limitations are discussed. Finally, useful recommendations that may help in practical model comparisons with these methods are provided.Keywords: cross-validation, importance sampling, information criteria, predictive accuracy
Procedia PDF Downloads 3929711 Multi-Objective Optimization of Run-of-River Small-Hydropower Plants Considering Both Investment Cost and Annual Energy Generation
Authors: Amèdédjihundé H. J. Hounnou, Frédéric Dubas, François-Xavier Fifatin, Didier Chamagne, Antoine Vianou
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This paper presents the techno-economic evaluation of run-of-river small-hydropower plants. In this regard, a multi-objective optimization procedure is proposed for the optimal sizing of the hydropower plants, and NSGAII is employed as the optimization algorithm. Annual generated energy and investment cost are considered as the objective functions, and number of generator units (n) and nominal turbine flow rate (QT) constitute the decision variables. Site of Yeripao in Benin is considered as the case study. We have categorized the river of this site using its environmental characteristics: gross head, and first quartile, median, third quartile and mean of flow. Effects of each decision variable on the objective functions are analysed. The results gave Pareto Front which represents the trade-offs between annual energy generation and the investment cost of hydropower plants, as well as the recommended optimal solutions. We noted that with the increase of the annual energy generation, the investment cost rises. Thus, maximizing energy generation is contradictory with minimizing the investment cost. Moreover, we have noted that the solutions of Pareto Front are grouped according to the number of generator units (n). The results also illustrate that the costs per kWh are grouped according to the n and rise with the increase of the nominal turbine flow rate. The lowest investment costs per kWh are obtained for n equal to one and are between 0.065 and 0.180 €/kWh. Following the values of n (equal to 1, 2, 3 or 4), the investment cost and investment cost per kWh increase almost linearly with increasing the nominal turbine flowrate while annual generated. Energy increases logarithmically with increasing of the nominal turbine flowrate. This study made for the Yeripao river can be applied to other rivers with their own characteristics.Keywords: hydropower plant, investment cost, multi-objective optimization, number of generator units
Procedia PDF Downloads 1579710 Multi-Generational Analysis of Perception and Acceptance of Mental Illnesses: Current Indian Context
Authors: Anvi Kumar
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This paper explores the attitudes and awareness of multiple generations ranging from Boomers I to GenZ (i.e. from 1954 to 2012) towards mental health issues. A convenient sample of 191 people was gathered in India aged 11-77. 20 people each were considered from 5 generational cohorts, namely- Boomers I, Boomers II, Gen X, Millennials, and Gen Z. The study tool comprised a survey that included demographic questions and the Community Attitude towards Mental Illness (CAMI) scale by Taylor & Dear (1981). Descriptive statistics, ANOVA, and Bonferonni’s post-hoc analysis have been used to perform the analysis. The findings reveal that the level of kindness towards those who struggle with mental health varies through certain age groups. An overall sense of exclusion of those struggling with mental health is prevalent among all age groups. GenZ’s awareness of mental health issues is primarily via social media, as against the rest of the generations seeking it from close relatives and friends. The study’s findings suggest a need to investigate further the quality of mental health knowledge content and its consumption pattern. Understanding the dynamics of information sharing and the potential for biases requires further discovery.Keywords: attitude, behaviour, mental illness, Gen Z, millennials, Gen Y, multi-generations, generational differences
Procedia PDF Downloads 759709 Experimental Investigation of S822 and S823 Wind Turbine Airfoils Wake
Authors: Amir B. Khoshnevis, Morteza Mirhosseini
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The paper deals with a sub-part of an extensive research program on the wake survey method in various Reynolds numbers and angles of attack. This research experimentally investigates the wake flow characteristics behind S823 and S822 airfoils in which designed for small wind turbines. Velocity measurements determined by using hot-wire anemometer. Data acquired in the wake of the airfoil at locations(c is the chord length): 0.01c - 3c. Reynolds number increased due to increase of free stream velocity. Results showed that mean velocity profiles depend on the angle of attack and location of data collections. Data acquired at the low Reynolds numbers (smaller than 10^5). Effects of Reynolds numbers on the mean velocity profiles are more significant in near locations the trailing edge and these effects decrease by taking distance from trailing edge toward downstream. Mean velocity profiles region increased by increasing the angle of attack, except for 7°, and also the maximum velocity deficit (velocity defect) increased. The difference of mean velocity in and out of the wake decreased by taking distance from trailing edge, and mean velocity profile become wider and more uniform.Keywords: angle of attack, Reynolds number, velocity deficit, separation
Procedia PDF Downloads 3779708 Comparison of Irradiance Decomposition and Energy Production Methods in a Solar Photovoltaic System
Authors: Tisciane Perpetuo e Oliveira, Dante Inga Narvaez, Marcelo Gradella Villalva
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Installations of solar photovoltaic systems have increased considerably in the last decade. Therefore, it has been noticed that monitoring of meteorological data (solar irradiance, air temperature, wind velocity, etc.) is important to predict the potential of a given geographical area in solar energy production. In this sense, the present work compares two computational tools that are capable of estimating the energy generation of a photovoltaic system through correlation analyzes of solar radiation data: PVsyst software and an algorithm based on the PVlib package implemented in MATLAB. In order to achieve the objective, it was necessary to obtain solar radiation data (measured and from a solarimetric database), analyze the decomposition of global solar irradiance in direct normal and horizontal diffuse components, as well as analyze the modeling of the devices of a photovoltaic system (solar modules and inverters) for energy production calculations. Simulated results were compared with experimental data in order to evaluate the performance of the studied methods. Errors in estimation of energy production were less than 30% for the MATLAB algorithm and less than 20% for the PVsyst software.Keywords: energy production, meteorological data, irradiance decomposition, solar photovoltaic system
Procedia PDF Downloads 1429707 Testing the Impact of the Nature of Services Offered on Travel Sites and Links on Traffic Generated: A Longitudinal Survey
Authors: Rania S. Hussein
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Background: This study aims to determine the evolution of service provision by Egyptian travel sites and how these services change in terms of their level of sophistication over the period of the study which is ten years. To the author’s best knowledge, this is the first longitudinal study that focuses on an extended time frame of ten years. Additionally, the study attempts to determine the popularity of these websites through the number of links to these sites. Links maybe viewed as the equivalent of a referral or word of mouth but in an online context. Both popularity and the nature of the services provided by these websites are used to determine the traffic on these sites. In examining the nature of services provided, the website itself is viewed as an overall service offering that is composed of different travel products and services. Method: This study uses content analysis in the form of a small scale survey done on 30 Egyptian travel agents’ websites to examine whether Egyptian travel websites are static or dynamic in terms of the services that they provide and whether they provide simple or sophisticated travel services. To determine the level of sophistication of these travel sites, the nature and composition of products and services offered by these sites were first examined. A framework adapted from Kotler (1997) 'Five levels of a product' was used. The target group for this study consists of companies that do inbound tourism. Four rounds of data collection were conducted over a period of 10 years. Two rounds of data collection were made in 2004 and two rounds were made in 2014. Data from the travel agents’ sites were collected over a two weeks period in each of the four rounds. Besides collecting data on features of websites, data was also collected on the popularity of these websites through a software program called Alexa that showed the traffic rank and number of links of each site. Regression analysis was used to test the effect of links and services on websites as independent variables on traffic as the dependent variable of this study. Findings: Results indicate that as companies moved from having simple websites with basic travel information to being more interactive, the number of visitors illustrated by traffic and the popularity of those sites increase as shown by the number of links. Results also show that travel companies use the web much more for promotion rather than for distribution since most travel agents are using it basically for information provision. The results of this content analysis study taps on an unexplored area and provide useful insights for marketers on how they can generate more traffic to their websites by focusing on developing a distinctive content on these sites and also by focusing on the visibility of their sites thus enhancing the popularity or links to their sites.Keywords: levels of a product, popularity, travel, website evolution
Procedia PDF Downloads 3219706 Computational Study of Flow and Heat Transfer Characteristics of an Incompressible Fluid in a Channel Using Lattice Boltzmann Method
Authors: Imdat Taymaz, Erman Aslan, Kemal Cakir
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The Lattice Boltzmann Method (LBM) is performed to computationally investigate the laminar flow and heat transfer of an incompressible fluid with constant material properties in a 2D channel with a built-in triangular prism. Both momentum and energy transport is modelled by the LBM. A uniform lattice structure with a single time relaxation rule is used. Interpolation methods are applied for obtaining a higher flexibility on the computational grid, where the information is transferred from the lattice structure to the computational grid by Lagrange interpolation. The flow is researched on for different Reynolds number, while Prandtl number is keeping constant as a 0.7. The results show how the presence of a triangular prism effects the flow and heat transfer patterns for the steady-state and unsteady-periodic flow regimes. As an evaluation of the accuracy of the developed LBM code, the results are compared with those obtained by a commercial CFD code. It is observed that the present LBM code produces results that have similar accuracy with the well-established CFD code, as an additionally, LBM needs much smaller CPU time for the prediction of the unsteady phonema.Keywords: laminar forced convection, lbm, triangular prism
Procedia PDF Downloads 3739705 Study of Bifurcation Curve with Aspect Ratio at Low Reynolds Number
Authors: Amit K. Singh, Subhankar Sen
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The bifurcation curve of separation in steady two-dimensional viscous flow past an elliptic cylinder is studied by varying the angle of incidence (α) with different aspect ratio (ratio of minor to major axis). The solutions are based on numerical investigation, using finite element analysis, of the Navier-Stokes equations for incompressible flow. Results are presented for Reynolds number up to 50 and angle of incidence varies from 0° to 90°. Range of aspect ratio (Ar) is from 0.1 to 1 (in steps of 0.1) and flow is considered as unbounded flow. Bifurcation curve represents the locus of Reynolds numbers (Res) at which flow detaches or separates from the surface of the body at a given α and Ar. In earlier studies, effect of Ar on laminar separation curve or bifurcation curve is limited for Ar = 0.1, 0.2, 0.5 and 0.8. Some results are also available at α = 90° and 45°. The present study attempts to provide a systematic data and clear understanding on the effect of Ar at bifurcation curve and its point of maxima. In addition, issues regarding location of separation angle and maximum ratio of coefficient of lift to drag are studied. We found that nature of curve, separation angle and maximum ratio of lift to drag changes considerably with respect to change in Ar.Keywords: aspect ratio, bifurcation curve, elliptic cylinder, GMRES, stabilized finite-element
Procedia PDF Downloads 3429704 Horticulture Therapy: A Healing Tool for Combating Depression
Authors: Eric Spruth, Lindsey Herbert, Danielle DiCristofano, Isis Violet Spruth, Drake Von Spruth
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Turning dreams into reality, the lifelong passion of Mr. Spruth and the company is to transform garbage-filled courtyards into flourishing flower and vegetable gardens, bringing light, hope, and wellness to not just the space but to the populations served within these public and private spaces. As an Expressive Art Therapist at Cook County Jail, Eric Spruth has implemented gardening projects, mobile radish carts, plant fostering systems, and large-scale murals. Lindsey Herbert, the Manager of Operations and Events at the International Museum of Surgical Science, supports gardening projects with Mr. Spruth along the front lawn of the museum, which will eventually accumulate into a community wellness garden. Mr. Spruth and Ms. Herbert both have dedicated efforts towards fostering awareness of hope and help and accountability for physical and mental wellbeing. Medicinal plants can rightfully be called one of nature’s wonderful healing tools with therapeutic powers. They can inhibit and kill bacteria, lower blood pressure, blood cholesterol, and blood sugar, prevent blood clotting, boost the immune system, and serve as a digestive aid. Some plants have the ability to stimulate the lymphatic system, which expedites the removal of waste products from the body to fight off evil toxins. Many plants are considered effective antioxidants to protect cells against free radical damage, serving to prevent some forms of cancer, heart disease, strokes, and viral infections. Garlic alone can provide us with over two hundred unusual chemicals that have the capability of protecting the human body from a wide variety of diseases. Besides the medicinal qualities of plants, plant and vegetable gardens also have an echoing effect on non-participants to look at something beautiful rather than a concrete courtyard or an unkempt lawn in front of a beautiful building. Plants also purify spaces and affect mood with color therapy. Collective gardening can foster a sense of community and purpose. Additionally, by recognizing the ever-evolving planet with global warming, horticulture therapy teaches important lessons in responsibility, accountability, and sustainability. Growing local food provides an opportunity to be involved in your own mental and physical health and gives you a chance for your own self-resilience, combating depression and a lack of nutrition. In adolescents, the process of watering and caring for plants can teach important life lessons that transcend beyond the garden by providing knowledge on how to care for yourself and how to be an active member of society. It also gives a sense of purpose and pride in transforming a small seed into a plant that can be consumed or enjoyed by others. Mr. Spruth and Ms. Herbert recognize the importance of bringing more green spaces to urban areas, both to serve a nutritional benefit and provide a beautiful transformation to underutilized areas. Gardens can bring beauty, wellness, and hope to dark spaces and provide immeasurable benefits for all.Keywords: growth, hope, mental health, sustainability, transformation, wellness
Procedia PDF Downloads 929703 Reconstruction and Renewal of Traditional Houses and its Impact on Tourism Development in Rasht
Authors: Parvaneh Ziviyar, Simin Armaghan
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Traditional house in Rasht contains monuments and heritage of ancestors who once lived in these houses. These houses represent the customs, culture and lifestyle of the people of Rasht and bridge the gap between modern people and their past that is being forgotten. Maintenance of the buildings and architectural heritage together with their unique architecture and climatic related construction has an important role in tourism attraction and sustainable development. The purpose of this study was to develop a new definition of vacation shacks that is different with the definition of Cultural Heritage Organization. The place to stay and visit that is rebuilt or renovated based on traditional architectural style of Rasht and yet provides modern amenities so that it would not undermine indigenous traditional sense of the house. Data collection for this study is based on review of literature and field study. Results and the statistics of this study will prove that the research hypothesis is supported and there is a correlation between traditional houses of Rasht, as tourism–accommodation place and tourist attraction. It also indicates the capability and potential of these ancient monuments in the introduction of the culture of this land, and calling people and many tourists come to visit and stay in such places.Keywords: architecture, traditional houses, vacation shacks, tourism
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