Search results for: frequency of visit
Commenced in January 2007
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Edition: International
Paper Count: 4399

Search results for: frequency of visit

3139 Analysis of Vibration of Thin-Walled Parts During Milling Made of EN AW-7075 Alloy

Authors: Jakub Czyżycki, Paweł Twardowski

Abstract:

Thin-walled components made of aluminum alloys are increasingly found in many fields of industry, and they dominate the aerospace industry. The machining of thinwalled structures encounters many difficulties related to the high susceptibility of the workpiece, which causes vibrations including the most unfavorable ones called chatter. The effect of these phenomena is the difficulty in obtaining the required geometric dimensions and surface quality. The purpose of this study is to analyze vibrations arising during machining of thin-walled workpieces made of aluminum alloy EN AW-7075. Samples representing actual thin-walled workpieces were examined in a different range of dimensions characterizing thin-walled workpieces. The tests were carried out in HSM high-speed machining (cutting speed vc = 1400 m/min) using a monolithic solid carbide endmill. Measurement of vibration was realized using a singlecomponent piezoelectric accelerometer 4508C from Brüel&Kjær which was mounted directly on the sample before machining, the measurement was made in the normal feed direction AfN. In addition, the natural frequency of the tested thin-walled components was investigated using a laser vibrometer for an broader analysis of the tested samples. The effect of vibrations on machining accuracy was presented in the form of surface images taken with an optical measuring device from Alicona. A classification of the vibrations produced during the test was carried out, and were analyzed in both the time and frequency domains. Observed significant influence of the thickness of the thin-walled component on the course of vibrations during machining.

Keywords: high-speed machining, thin-walled elements, thin-walled components, milling, vibrations

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3138 Exploring Factors That Affect the Utilisation of Antenatal Care Services: Perceptions of Women in Mangwe Rural District, Zimbabwe

Authors: Leoba Nyathi, Augustine K. Tugli, Takalani G. Tshitangano

Abstract:

Use of health care services is an effective way of improving maternal and child health outcomes, especially in the rural areas. The study aimed to find out the perceptions of women on factors that affect the utilisation of antenatal care services (ANC) in Mangwe Rural District, Zimbabwe. The study was conducted in Mabunga village which is situated in Mangwe Rural District, Matabeleland South Province, Zimbabwe. A qualitative approach using explorative and descriptive design was adopted for the study. A sample of ten women were chosen from the target population by means of convenience sampling and data was collected through semi-structured interviews. Interviews and discussions were audio-taped, transcribed and coded into themes and subthemes. The study results showed that access factors, socio-cultural factors, demographic factors, quality of care and knowledge about antenatal care services were the major factors affecting utilisation of ANC services in Mangwe Rural District. It was discovered that the geographical location of the village to the health care centres has a great impact on utilisation of services. All the women did not initiate ANC services as recommended and they also did not adhere to the number of times they were supposed to visit the health care centres. The findings concluded that women have the knowledge about ANC and they all attended at least once during their last pregnancy. However, inconsistencies in attendance were shown due to access, socio-cultural and demographic factors.

Keywords: antenatal care services, women, utilisation, affect, factors, perceptions

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3137 Exploring Introducing a Plant-Based Diet into Patient Education in the Primary Care Setting, and the Positive Effects on Combatting Common Chronic Illnesses Such as Hypertension, Hyperlipidemia, and Diabetes Mellitus Type II

Authors: Arielle Ferdinand

Abstract:

A plant-based diet focuses on foods from plant sources, limiting or altogether omitting animal products. Some of the most common chronic illnesses seen in primary care are hypertension, hyperlipidemia, and diabetes type II. These common chronic illnesses can often be debilitating, costly, time-consuming, and, when left untreated, can lead to an early death. Treatment and maintenance of care are also labor intensive for the patient. They are often required to have at least four blood pressure checks yearly and a hemoglobin A1C checked quarterly. Though preventative interventions and prevention education should be included in patient visits in the primary care setting, education about dietary interventions, such as a plant-based diet, also yields positive outcomes for patients who already have hypertension, hyperlipidemia, and diabetes mellitus type 2. Evidence will show that incorporating a plant-based diet results in decreased blood pressure, as well as decreased levels of LDL-C, improved post-prandial glucose levels, and a reduction in HbA1C. It is cost-effective for the patient by generally lower grocery costs, and it can either reduce or prevent the need to pay for more office visits and pharmacotherapy. Incorporating this method of dietary changes is an easy intervention during a primary care office visit that would greatly benefit the patient in many ways.

Keywords: plant-based, nutrition, diabetes, hyperlipidemia

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3136 Auditory Effects among 18-45 Years Old Workers of a Textile Plant in Seeduwa, Sri Lanka

Authors: P. G. S. Madushani, L. D. Illeperuma

Abstract:

Abstract Noise is one of the most common physical hazards in industrial settings. The prevalence of Noise Induced Hearing Loss (NIHL) is on the rise with increasedduration of exposure and the increase in the severity of hearing loss. The purpose of the study was to determine auditory effects among textile workers and to establish associations between the degree of hearing loss and exposure duration, degree of hearing loss and noise level and the proportion of hearing related complaints. A cross sectional descriptive study using purposive sampling was carried out. An interviewer administered questionnaire and Distortion Product Oto Acoustic Emission (DPOAE) hearing screening on 127 (72 female and 55 male) textile workers of the selected textile plant in Seeduwa, Sri Lanka was done (Age: M= 31.16, SD=7.75). Noise measurements were done in six sections of the factory and average noise levels were obtained. Diagnostic hearing evaluations were done for 60 (57.75%) subjects, referred from the DPOAE hearing screening test. The degree of hearing loss and the exposure duration had a significant association in the high frequency region of 4 kHz to 8 kHz (p < 0.05). Noise levels fluctuated between 90.3±0.8 dBA and 50.6. ±0.52 dBA. 30.83% of workers reported having NIHL. Most of the workers (33.9%) complained difficulty in conversing in noisy backgrounds. Other complaints as tinnitus, dizziness, ear fullness and headache were reported in less than 30%. workers who were exposed to noise for more than 15 years were affected with NIHL in the high frequency region. Administrative controls and engineering controls need to be implemented to manage hazardous noise levels in industrial settings. Hearing Conservation Programs should be initiated and implemented for textile workers.

Keywords: textile industry, NIHL, degree of hearing loss, noise levels, auditory effects

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3135 Coherent All-Fiber and Polarization Maintaining Source for CO2 Range-Resolved Differential Absorption Lidar

Authors: Erwan Negre, Ewan J. O'Connor, Juha Toivonen

Abstract:

The need for CO2 monitoring technologies grows simultaneously with the worldwide concerns regarding environmental challenges. To that purpose, we developed a compact coherent all-fiber ranged-resolved Differential Absorption Lidar (RR-DIAL). It has been designed along a tunable 2x1fiber optic switch set to a frequency of 1 Hz between two Distributed FeedBack (DFB) lasers emitting in the continuous-wave mode at 1571.41 nm (absorption line of CO2) and 1571.25 nm (CO2 absorption-free line), with linewidth and tuning range of respectively 1 MHz and 3 nm over operating wavelength. A three stages amplification through Erbium and Erbium-Ytterbium doped fibers coupled to a Radio Frequency (RF) driven Acousto-Optic Modulator (AOM) generates 100 ns pulses at a repetition rate from 10 to 30 kHz with a peak power up to 2.5 kW and a spatial resolution of 15 m, allowing fast and highly resolved CO2 profiles. The same afocal collection system is used for the output of the laser source and the backscattered light which is then directed to a circulator before being mixed with the local oscillator for heterodyne detection. Packaged in an easily transportable box which also includes a server and a Field Programmable Gate Array (FPGA) card for on-line data processing and storing, our setup allows an effective and quick deployment for versatile in-situ analysis, whether it be vertical atmospheric monitoring, large field mapping or sequestration site continuous oversight. Setup operation and results from initial field measurements will be discussed.

Keywords: CO2 profiles, coherent DIAL, in-situ atmospheric sensing, near infrared fiber source

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3134 A Case Study on Effectiveness of Hijamah (Wet Cupping) on Numbness of Foot in Diabetic Patient

Authors: Nafdha Thajudeen

Abstract:

Hijamah therapy is one of the leading alternative & complementary modalities in the World. It is a kind of detoxification, rejuvenation, and blood purification method. It comes under Ilaj bil Tadbeer (Regimental therapy) in the Unani medical system. In diabetes, hands and foot care in people is very important because of slow blood circulation, where blood sometimes is not able to fully penetrate the capillaries. Hijamah therapy works upon the following two principles- Tanqiyae Mawad (Evacuation of morbid humor) and Imalae Mawad (Diversion of humor). The aim of this study was to find out the effectiveness of hijamah therapy on the numbness of legs in a diabetic patient. This case study was carried out in Ayurvedic Research Hospital (Non-Communicable Diseases), Ninthavur, Sri Lanka. A 63 years old female diabetic patient came to the clinic with the complain of numbness in both feet for one year. The treatment history of the patient revealed that she had taken western medicine for her complaints for 7 months. In her first visit, wet cupping was done on local and distal points. The patient said there was a remarkable improvement; internal medicines were given to keep the sugar level in normal with some external applications. Every week, wet cupping was done on the same points, with repeating the same medicines. Foot numbness was fully cured within one month. The finding of this study shows that the complaint of numbness in the diabetic patient was treated with hijamah therapy with internal & external medicine. This case study can be concluded as hijamah therapy is very effective in treating diabetic numbness. This single case study may be the entrance for future clinical studies

Keywords: Hijamah therapy, Ilaj bil thadbeer, diabetes, numbness

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3133 Analysis of Accessibility of Tourism Transportation in Banyuwangi

Authors: Lilla Anjani, Ervina Ahyudanari

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Tourism is one of the contributors to regional economic income. Banyuwangi has made rapid developments related to the tourism sector, especially since 2010. There are 25 tourist visit locations that can become tourist destinations. Banyuwangi has tourism transportation to support the ease of reaching tourist places. This transportation operates with six routes, namely the final destination of Ijen Crater, Glenmore, Bajangan, Bangsring, Red Island, and Pine Forest. Despite having tourism transportation, tourists tend to choose to use a private car or rent a car because there is no access to tourist places using public transportation. Tourism transportation is also one form of sustainable tourism development in the future, such as the Sustainable Development Goals. The Banyuwangi government has a special program for tourism development that is supported by all sectors in Banyuwangi. To support the development of tourism in Banyuwangi, it is necessary to analyze existing tourism transportation as well as suggestions regarding new routes to reach all tourism locations in Banyuwangi Regency. The analysis reviewed in this study is an analysis of accessibility, distance, and time to the tourism location. There are 30 tourism destination points from 39 ODTW references from the transportation service, and the tourism office of Banyuwangi Regency Banyuwangi tourism objects can be divided into six zones based on travel time and distance. The highest accessibility value for Zone A is 51.96, and the lowest is 11.989. The highest accessibility value for Zone B is 33.4269, and the lowest is 21.737. The highest accessibility value for Zone C is 33,407, and the lowest is 14,848. The highest accessibility value for Zone D is 58,967, and the lowest is 14,742. The highest accessibility value for Zone E is 56,401, and the lowest is 14.1. The highest accessibility value for Zone F is 176.14, and the lowest is 44.1. There are two tourist transportation routes with six sessions every day. The resulting new route is in the form of grouping based on locations that can be reached in one particular area.

Keywords: accessibility, tourism clustering, Banyuwangi tourism, sustainable development goals

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3132 On the convergence of the Mixed Integer Randomized Pattern Search Algorithm

Authors: Ebert Brea

Abstract:

We propose a novel direct search algorithm for identifying at least a local minimum of mixed integer nonlinear unconstrained optimization problems. The Mixed Integer Randomized Pattern Search Algorithm (MIRPSA), so-called by the author, is based on a randomized pattern search, which is modified by the MIRPSA for finding at least a local minimum of our problem. The MIRPSA has two main operations over the randomized pattern search: moving operation and shrinking operation. Each operation is carried out by the algorithm when a set of conditions is held. The convergence properties of the MIRPSA is analyzed using a Markov chain approach, which is represented by an infinite countable set of state space λ, where each state d(q) is defined by a measure of the qth randomized pattern search Hq, for all q in N. According to the algorithm, when a moving operation is carried out on the qth randomized pattern search Hq, the MIRPSA holds its state. Meanwhile, if the MIRPSA carries out a shrinking operation over the qth randomized pattern search Hq, the algorithm will visit the next state, this is, a shrinking operation at the qth state causes a changing of the qth state into (q+1)th state. It is worthwhile pointing out that the MIRPSA never goes back to any visited states because the MIRPSA only visits any qth by shrinking operations. In this article, we describe the MIRPSA for mixed integer nonlinear unconstrained optimization problems for doing a deep study of its convergence properties using Markov chain viewpoint. We herein include a low dimension case for showing more details of the MIRPSA, when the algorithm is used for identifying the minimum of a mixed integer quadratic function. Besides, numerical examples are also shown in order to measure the performance of the MIRPSA.

Keywords: direct search, mixed integer optimization, random search, convergence, Markov chain

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3131 Data Compression in Ultrasonic Network Communication via Sparse Signal Processing

Authors: Beata Zima, Octavio A. Márquez Reyes, Masoud Mohammadgholiha, Jochen Moll, Luca de Marchi

Abstract:

This document presents the approach of using compressed sensing in signal encoding and information transferring within a guided wave sensor network, comprised of specially designed frequency steerable acoustic transducers (FSATs). Wave propagation in a damaged plate was simulated using commercial FEM-based software COMSOL. Guided waves were excited by means of FSATs, characterized by the special shape of its electrodes, and modeled using PIC255 piezoelectric material. The special shape of the FSAT, allows for focusing wave energy in a certain direction, accordingly to the frequency components of its actuation signal, which makes available a larger monitored area. The process begins when a FSAT detects and records reflection from damage in the structure, this signal is then encoded and prepared for transmission, using a combined approach, based on Compressed Sensing Matching Pursuit and Quadrature Amplitude Modulation (QAM). After codification of the signal is in binary chars the information is transmitted between the nodes in the network. The message reaches the last node, where it is finally decoded and processed, to be used for damage detection and localization purposes. The main aim of the investigation is to determine the location of detected damage using reconstructed signals. The study demonstrates that the special steerable capabilities of FSATs, not only facilitate the detection of damage but also permit transmitting the damage information to a chosen area in a specific direction of the investigated structure.

Keywords: data compression, ultrasonic communication, guided waves, FEM analysis

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3130 Patients’ Perspective on Early Discharge with Drain in situ after Breast Cancer Surgery

Authors: Laila Al-Balushi, Suad Al-Kharosui

Abstract:

Due to the increasing number of breast cancer cases in Oman and the impact of the novel coronavirus disease 2019 (COVID-19 on bed situation in the hospital, a policy of early discharge (ED) with drain after breast cancer surgery was initiated at one of the tertiary hospitals in Oman. The uniqueness of this policy is no home visit follow-up, conducted after discharge and the main mode of communication was Instagram media. This policy then was evaluated by conducting a quasi-experimental study using a questionnaire with ten open and closed-ended questions, five questions to explore patient experience using a five-point Likert scale. A total of 41 female patients responded to the questionnaire. Almost 96% of the participants stated being well informed about drain care pre- and post-surgery at home. 9% of the participants developed early sign of infection and was managed at out-patient clinics. Participants with bilateral drains expressed more pain than those with single drain. 90% stated satisfied being discharged with breast drain whereas 10% preferred to stay in the hospital until the drains were removed. This study found that the policy of ED with a drain after BC surgery is practical and well-accepted by most patients. The role of breast nurse and presence of family and institutional support enhanced the success of the policy implementation. To optimize patient care, conducting a training program by breast nurse for nurses at local health centres about care management of patients with drain could improve care and enhance patient satisfaction.

Keywords: breast cancer, surgery, early discharge, surgical drain

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3129 Oral Fluency: A Case Study of L2 Learners in Canada

Authors: Maaly Jarrah

Abstract:

Oral fluency in the target language is what many second language learners hope to achieve by living abroad. Research in the past has demonstrated the role informal environments play in improving L2 learners' oral fluency. However, living in the target country and being part of its community does not ensure the development of oral fluency skills. L2 learners' desire to communicate and access to speaking opportunities in the host community are key in achieving oral fluency in the target language. This study attempts to identify differences in oral fluency, specifically speech rate, between learners who communicate in the L2 outside the classroom and those who do not. In addition, as the desire to communicate is a crucial factor in developing oral fluency, this study investigates whether or not learners' desire to speak the L2 outside the classroom plays a role in their frequency of L2 use outside the classroom. Finally, given the importance of the availability of speaking opportunities for L2 learners in order to practice their speaking skills, this study reports on the participants' perceptions of the speaking opportunities accessible to them in the target community while probing whether or not their perceptions differed based on their oral fluency level and their desire to communicate. The results suggest that exposure to the target language and daily communication with the native speakers is strongly related to the development of learners' oral fluency. Moreover, the findings suggest that learners' desire to communicate affects their frequency of communication in their L2 outside the classroom. At the same time, all participants, regardless of their oral fluency level and their desire to communicate, asserted that speaking opportunities beyond the classroom are very limited. Finally, the study finds there are marked differences in the perceptions learners have regarding opportunities for learning offered by the same language program. After reporting these results, the study concludes with recommendations for ESL programs that serve international students.

Keywords: ESL programs, L2 Learners, oral fluency, second language

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3128 Lexical-Semantic Processing by Chinese as a Second Language Learners

Authors: Yi-Hsiu Lai

Abstract:

The present study aimed to elucidate the lexical-semantic processing for Chinese as second language (CSL) learners. Twenty L1 speakers of Chinese and twenty CSL learners in Taiwan participated in a picture naming task and a category fluency task. Based on their Chinese proficiency levels, these CSL learners were further divided into two sub-groups: ten CSL learners of elementary Chinese proficiency level and ten CSL learners of intermediate Chinese proficiency level. Instruments for the naming task were sixty black-and-white pictures: thirty-five object pictures and twenty-five action pictures. Object pictures were divided into two categories: living objects and non-living objects. Action pictures were composed of two categories: action verbs and process verbs. As in the naming task, the category fluency task consisted of two semantic categories – objects (i.e., living and non-living objects) and actions (i.e., action and process verbs). Participants were asked to report as many items within a category as possible in one minute. Oral productions were tape-recorded and transcribed for further analysis. Both error types and error frequency were calculated. Statistical analysis was further conducted to examine these error types and frequency made by CSL learners. Additionally, category effects, pictorial effects and L2 proficiency were discussed. Findings in the present study helped characterize the lexical-semantic process of Chinese naming in CSL learners of different Chinese proficiency levels and made contributions to Chinese vocabulary teaching and learning in the future.

Keywords: lexical-semantic processing, Mandarin Chinese, naming, category effects

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3127 Feasibility Study of MongoDB and Radio Frequency Identification Technology in Asset Tracking System

Authors: Mohd Noah A. Rahman, Afzaal H. Seyal, Sharul T. Tajuddin, Hartiny Md Azmi

Abstract:

Taking into consideration the real time situation specifically the higher academic institutions, small, medium to large companies, public to private sectors and the remaining sectors, do experience the inventory or asset shrinkages due to theft, loss or even inventory tracking errors. This happening is due to a zero or poor security systems and measures being taken and implemented in their organizations. Henceforth, implementing the Radio Frequency Identification (RFID) technology into any manual or existing web-based system or web application can simply deter and will eventually solve certain major issues to serve better data retrieval and data access. Having said, this manual or existing system can be enhanced into a mobile-based system or application. In addition to that, the availability of internet connections can aid better services of the system. Such involvement of various technologies resulting various privileges to individuals or organizations in terms of accessibility, availability, mobility, efficiency, effectiveness, real-time information and also security. This paper will look deeper into the integration of mobile devices with RFID technologies with the purpose of asset tracking and control. Next, it is to be followed by the development and utilization of MongoDB as the main database to store data and its association with RFID technology. Finally, the development of a web based system which can be viewed in a mobile based formation with the aid of Hypertext Preprocessor (PHP), MongoDB, Hyper-Text Markup Language 5 (HTML5), Android, JavaScript and AJAX programming language.

Keywords: RFID, asset tracking system, MongoDB, NoSQL

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3126 Genetic Characterization of a Composite Transposon Carrying armA and Aac(6)-Ib Genes in an Escherichia coli Isolate from Egypt

Authors: Omneya M. Helmy, Mona T. Kashef

Abstract:

Aminoglycosides are used in treating a wide range of infections caused by both Gram-negative and Gram positive bacteria. The presence of 16S rRNA methyl transferases (16S-RMTase) is among the newly discovered resistance mechanisms that confer high resistance to clinically useful aminoglycosides. Cephalosporins are the most commonly used antimicrobials in Egypt; therefore, this study was conducted to determine the isolation frequency of 16S rRNA methyl transferases among third generation cephalosporin-resistant clinical isolates in Egypt. One hundred and twenty three cephalosporin resistant Gram-negative clinical isolates were screened for aminoglycoside resistance by the Kirby Bauer disk diffusion method and tested for possible production of 16S-RMTase. PCR testing and sequencing were used to confirm the presence of 16S-RMTase and the associated antimicrobial resistance determinants, as well as the genetic region surrounding the armA gene. Out of 123 isolates, 66 (53.66%) were resistant to at least one aminoglycoside antibiotic. Only one Escherichia coli isolate (E9ECMO) which was totally resistant to all tested aminoglycosides, was confirmed to have the armA gene in association with blaTEM-1, blaCTX-M-15, blaCTX-M-14 and aac(6)-Ib genes. The armA gene was found to be carried on a large A/C plasmid. Genetic mapping of the armA surrounding region revealed, for the first time, the association of armA with aac(6)-Ib on the same transposon. In Conclusion, the isolation frequency of 16S-RMTase was low among the tested cephalosporin-resistant clinical samples. However, a novel composite transposon has been detected conferring high-level aminoglycosides resistance.

Keywords: aminoglcosides, armA gene, β lactmases, 16S rRNA methyl transferases

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3125 Histopathological Spectrum of Skin Lesions in the Elderly: Experience from a Tertiary Hospital in Southeast Nigeria

Authors: Ndukwe, Chinedu O.

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Background: There are only a few epidemiological studies published on skin disorders in the elderly within the Nigerian context and none from the Southeast Region of the country. In addition, none of these studies has considered the pattern and frequency of histopathologically diagnosed geriatric skin lesions. Hence, we attempted to determine the frequency as well as the age and gender distributions of histologically diagnosed dermatological diseases in the geriatric population from skin biopsies submitted to the histopathology department of a tertiary care hospital in Southeast Nigeria. Material and methods: This is a cross-sectional retrospective hospital-based study involving all skin biopsies of patients 60 years and above, received at the Department of Histopathology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria from January 2004 to December 2019. Results: During the study period, 751 skin biopsies were received in the histopathology department. Of these, 142 were from patients who were older than 60 years. Thus, the overall share of geriatric patients was 18.9%. The mean age at presentation was 71.1 ± 8.6 years. The M: F was 1:1 and most of the patients belonged to the age group of 60–69 years (69 cases, 48.6%). The mean age of the male patients was 72.1±9.5 years. In the female patients, it was 70.1±7.5 years. The commonest disease category was neoplasms (91, 64.1%). Most neoplasms were malignant. There were 67/142 (47.2%) malignant lesions. Commonest was Squamous cell carcinoma (SCC) (30 cases) which is 21.1% of all geriatric skin biopsies and 44.8% of malignant skin biopsies. This is closely followed by melanoma (29 cases). Conclusion: Malignant neoplasms, benign neoplasms and papulosquamous disorders are the three commonest histologically diagnosed skin lesions in our geriatric population. The commonest skin malignancies in this group of patients are squamous cell carcinoma and malignant melanoma.

Keywords: geriatric, skin, Nigeria, histopathology

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3124 Adult Learners’ Code-Switching in the EFL Classroom: An Analysis of Frequency and Type of Code-Switching

Authors: Elizabeth Patricia Beck

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Stepping into various English as foreign language classrooms, one will see some fundamental similarities. There will likely be groups of students working collaboratively, possibly sitting at tables together. They will be using a set coursebook or photocopies of materials developed by publishers or the teacher. The teacher will be carefully monitoring students’ behaviour and progress. The teacher will also likely be insisting that the students only speak English together, possibly having implemented a complex penalty and award systems to encourage this. This is communicative language teaching and it is commonly how foreign languages are taught around the world. Recently, there has been much interest in the codeswitching behaviour of learners in foreign or second language classrooms. It is a significant topic as it relates to second language acquisition theory, language teaching training and policy, and student expectations and classroom practice. Generally in an English as a foreign language context, an ‘English Only’ policy is the norm. This is based on historical factors, socio-political influence and theories surrounding language learning. The trend, however, is shifting and, based on these same factors, a re-examination of language use in the foreign language classroom is taking place. This paper reports the findings of an examination into the codeswitching behaviour of learners with a shared native language in an English classroom. Specifically, it addresses the question of classroom code-switching by adult learners in the EFL classroom during student-to-student, spoken interaction. Three generic categories of code switching are proposed based on published research and classroom practice. Italian adult learners at three levels were observed and patterns of language use were identified, recorded and analysed using the proposed categories. After observations were completed, a questionnaire was distributed to the students focussing on attitudes and opinions around language choice in the EFL classroom, specifically, the usefulness of L1 for specific functions in the classroom. The paper then investigates the relationship between learners’ foreign language proficiency and the frequency and type of code-switching that they engaged in, and the relationship between learners’ attitudes to classroom code-switching and their behaviour. Results show that code switching patterns underwent changes as the students’ level of English language proficiency improved, and that students’ attitudes towards code-switching generally correlated with their behaviour with some exceptions, however. Finally, the discussion focusses on the details of the language produced in observation, possible influencing factors that may affect the frequency and type of code switching that took place, and additional influencing factors that may affect students’ attitudes towards code switching in the foreign language classroom. An evaluation of the limitations of this study is offered and some suggestions are made for future research in this field of study.

Keywords: code-switching, EFL, second language aquisition, adult learners

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3123 Formal Thai National Costume in the Reign of King Bhumibol Adulyadej

Authors: Chanoknart Mayusoh

Abstract:

The research about Formal Thai National Costume in the reign of King Bhumibol Adulyadej is an applied research that aimed to study the accurate knowledge concerning to Thai national costume in the reign of King Rama IX, also to study origin of all costumes in the reign of King Rama IX and to study the style, material used, and using accasion. This research methodology which are collect quanlitative data through observation, document, and photograph from key informant of costume in the reign of King Rama IX and from another who related to this field. The formal Thai national costume of the reign of King Bhumibol Adulyadej originated from the visit of His Majesty the King to Europe and America in 1960. Since Thailand had no traditional national costume; Her Majesty the Queen initiated the idea to create formal Thai national costumes. In 1964, Her Majesty the Queen selected 8 styles of formal Thai national costume. Later, Her Majesty the Queen confered another 3 formal Thai national costume for men. There are 8 styles of formal Thai national costume for women: Thai Ruean Ton, Thai Chit Lada, Thai Amarin, Thai Borom Phiman, Thai Siwalia, Thai Chakkri, Thai Dusit, and Thai Chakkraphat. There are 3 styles of formal Thai national costume for men: short-sleeve shirt, long-sleeve shirt, and long-sleeve shirt with breechcloth. The costume is widely used in formal ceremony such as greeting ceremony for official foreign visitors, wedding ceremony, or other auspicious ceremonies. Now a day, they are always used as a bridal gown as well. The formal Thai national costume is valuable art that shows Thai identity and, should be preserved for the next generation.

Keywords: formal Thai national costume for women, formal Thai national costume for men, His Majesty King Bhumibol Adulyadej the Great King Rama IX, Her Majesty Queen Sirikit Queen

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3122 Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and SHF Bands of Small Cell 5G Networks

Authors: Emanuel Teixeira, Anderson Ramos, Marisa Lourenço, Fernando J. Velez, Jon M. Peha

Abstract:

This article discusses the benefit cost analysis aspects of millimetre wavebands (mmWaves) and Super High Frequency (SHF). The devaluation along the distance of the carrier-to-noise-plus-interference ratio with the coverage distance is assessed by considering two different path loss models, the two-slope urban micro Line-of-Sight (UMiLoS) for the SHF band and the modified Friis propagation model, for frequencies above 24 GHz. The equivalent supported throughput is estimated at the 5.62, 28, 38, 60 and 73 GHz frequency bands and the influence of carrier-to-noise-plus-interference ratio in the radio and network optimization process is explored. Mostly owing to the lessening caused by the behaviour of the two-slope propagation model for SHF band, the supported throughput at this band is higher than at the millimetre wavebands only for the longest cell lengths. The benefit cost analysis of these pico-cellular networks was analysed for regular cellular topologies, by considering the unlicensed spectrum. For shortest distances, we can distinguish an optimal of the revenue in percentage terms for values of the cell length, R ≈ 10 m for the millimeter wavebands and for longest distances an optimal of the revenue can be observed at R ≈ 550 m for the 5.62 GHz. It is possible to observe that, for the 5.62 GHz band, the profit is slightly inferior than for millimetre wavebands, for the shortest Rs, and starts to increase for cell lengths approximately equal to the ratio between the break-point distance and the co-channel reuse factor, achieving a maximum for values of R approximately equal to 550 m.

Keywords: millimetre wavebands, SHF band, SINR, cost benefit analysis, 5G

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3121 Atom Probe Study of Early Stage of Precipitation on Binary Al-Li, Al-Cu Alloys and Ternary Al-Li-Cu Alloys

Authors: Muna Khushaim

Abstract:

Aluminum-based alloys play a key role in modern engineering, especially in the aerospace industry. Introduction of solute atoms such as Li and Cu is the main approach to improve the strength in age-hardenable Al alloys via the precipitation hardening phenomenon. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Comparing the random binomial frequency distribution and the experimental frequency distribution of concentrations in atom probe tomography data was used to investigate the early stage of decomposition in the different binary and ternary alloys which were experienced different heat treatments. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160 °C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160 °C) induces increasing on the number density of the Li clusters and hence increase number of precipitated δ' particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus, the results contribute to the understanding of Al-alloy design.

Keywords: aluminum alloy, atom probe tomography, early stage, decomposition

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3120 Effect of Irrigation and Hydrogel on the Water Use Efficiency of Zeto-Tiled Green-Gram Relay System in the Eastern Indo Gangetic-Plain

Authors: Benukar Biswas, S. Banerjee, P. K. Bandhyopadhyaya, S. K. Patra, S. Sarkar

Abstract:

Jute can be sown as relay crop in between the lines of 15-20 days old green gram for additional pulse yield without reducing the yield of jute. The main problem of this system is water use efficiency (WUE). The increase in water productivity and reduction in production cost were reported in the zero-tilled crop. The hydrogel can hold water up to 400 times of its weight and can release 95 % of the retained water. The present field study was carried out during 2015-16 at BCKV (tropical sub-humid, 1560 mm annual rainfall, 22058/ N, 88051/ E, 9.75 m AMSL, sandy loam soil, aeric Haplaquept, pH 6.75, organic carbon 5.4 g kg-1, available N 85 kg ha-1, P2O5 15.3 kg ha-1 and K2O 40 kg ha-1) with four levels of irrigation regimes: no irrigation - RF, cumulative pan evaporation 250mm (CPE250), CPE125 and CPE83 and three levels of hydrogel: no hydrogel (H0), 2.5 kg ha-1 (H2.5) and 5 kg ha-1 (H5). Throughout the crop growing period a linear positive relationship remained between Leaf Area Index (LAI) and evapotranspiration rate. The strength of the relationship between ETa and LAI started increasing and reached its peak at 7 WAS (R2=0.78) when green gram was at its maturity, and both the crops covered the nearly entire base area. This relation starts weakening from 13 WAS due to jute leaf shading. A linear relationship between system yield and ET was also obtained in the present study. The variation in system yield might be predicted 75% with ET alone. Effective rainfall was reduced with increasing irrigation frequency due to enhanced water supply in contrast to hydrogel application due to the difference in water storage capacity. Irrigation contributed a major source of variability of ET. Higher irrigation frequency resulted in higher ET loss ranging from 574 mm in RF to 764 mm in CPE83. Hydrogel application also increased water storage on a sustained basis and supplied to crops resulting higher ET from 639 mm in H0 to 671mm in H5. WUE ranged between 0.4 kg m-3 (RF) to 0.63 kg m-3 (CPE83 H5). WUE increased with increased application of irrigation water from 0.42 kg m-3 in RF to 0.57 kg m-3 in CPE 83. Hydrogel application significantly improves the WUE from 0.45 kg m-3 in H0 to 0.50 in H2.5 and 0.54 in H5. Under relatively dry root zone (RF), both evaporation and transpiration remain at suboptimal level resulting in lower ET as well as lower system yield. Green gram – jute relay system can be water use efficient with 38% higher yield with application of hydrogel @ 2.5 kg ha-1 under deficit irrigation regime of CPE 125 over rainfed system without application of the gel. Application of gel conditioner improved water storage, checked excess water loss from the system, and mitigated ET demand of the relay system for a longer time. Hence, irrigation frequency was reduced from five times at CPE 83 to only three times in CPE 125.

Keywords: zero tillage, deficit irrigation, hydrogel, relay system

Procedia PDF Downloads 232
3119 Comparative Analysis of Control Techniques Based Sliding Mode for Transient Stability Assessment for Synchronous Multicellular Converter

Authors: Rihab Hamdi, Amel Hadri Hamida, Fatiha Khelili, Sakina Zerouali, Ouafae Bennis

Abstract:

This paper features a comparative study performance of sliding mode controller (SMC) for closed-loop voltage control of direct current to direct current (DC-DC) three-cells buck converter connected in parallel, operating in continuous conduction mode (CCM), based on pulse-width modulation (PWM) with SMC based on hysteresis modulation (HM) where an adaptive feedforward technique is adopted. On one hand, for the PWM-based SM, the approach is to incorporate a fixed-frequency PWM scheme which is effectively a variant of SM control. On the other hand, for the HM-based SM, oncoming an adaptive feedforward control that makes the hysteresis band variable in the hysteresis modulator of the SM controller in the aim to restrict the switching frequency variation in the case of any change of the line input voltage or output load variation are introduced. The results obtained under load change, input change and reference change clearly demonstrates a similar dynamic response of both proposed techniques, their effectiveness is fast and smooth tracking of the desired output voltage. The PWM-based SM technique has greatly improved the dynamic behavior with a bit advantageous compared to the HM-based SM technique, as well as provide stability in any operating conditions. Simulation studies in MATLAB/Simulink environment have been performed to verify the concept.

Keywords: DC-DC converter, hysteresis modulation, parallel multi-cells converter, pulse-width modulation, robustness, sliding mode control

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3118 Association of Calcium Intake Adequacy with Wealth Indices among Selected Female Adults Living in Depressed and Non-Depressed Area in Metro Manila, Philippines

Authors: Maria Viktoria Melgo

Abstract:

This study aimed to determine the possible association between calcium intake and wealth indices of selected female adults. Specifically, it aimed to: a) determine the calcium intake adequacy of the respondents. b) determine the relationship, if any, between calcium intake adequacy, area and wealth indices. The study used the survey design and employed convenience sampling in selecting participants. Two hundred females aged 20 – 64 years old were covered in the study from depressed and non-depressed areas. Data collected were calcium intake taken from two 24-hour food recall and Food Frequency Questionnaire (FFQ) and wealth indices using housing characteristics, household assets and access to utilities and infrastructure. Descriptive statistics and Chi-square test were used to determine the frequency distribution and association between the given variables, respectively, using Statistical Package for Social Sciences (SPSS) and OpenEpi software. The results showed that there were 86% of respondents in the depressed area with an inadequate calcium intake while there were 78% of respondents in the non-depressed area with an adequate calcium intake. No significant relationship was obtained in most wealth indices with calcium intake adequacy and area but appliance and ownership of main material of the house showed a significant relationship to calcium intake adequacy by area. The study recommends that the Local Government Unit (LGU) should provide seminars or nutrition education that will further enhance the knowledge of the people in the community. The study also recommends to conduct a similar study but with different, larger sample size, different location nonetheless if it is in urban or rural and include the anthropometry measurement of the respondents.

Keywords: association, calcium intake adequacy, metro Manila, Philippines, wealth indices

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3117 Unraveling Language Contact through Syntactic Dynamics of ‘Also’ in Hong Kong and Britain English

Authors: Xu Zhang

Abstract:

This article unveils an indicator of language contact between English and Cantonese in one of the Outer Circle Englishes, Hong Kong (HK) English, through an empirical investigation into 1000 tokens from the Global Web-based English (GloWbE) corpus, employing frequency analysis and logistic regression analysis. It is perceived that Cantonese and general Chinese are contextually marked by an integral underlying thinking pattern. Chinese speakers exhibit a reliance on semantic context over syntactic rules and lexical forms. This linguistic trait carries over to their use of English, affording greater flexibility to formal elements in constructing English sentences. The study focuses on the syntactic positioning of the focusing subjunct ‘also’, a linguistic element used to add new or contrasting prominence to specific sentence constituents. The English language generally allows flexibility in the relative position of 'also’, while there is a preference for close marking relationships. This article shifts attention to Hong Kong, where Cantonese and English converge, and 'also' finds counterparts in Cantonese ‘jaa’ and Mandarin ‘ye’. Employing a corpus-based data-driven method, we investigate the syntactic position of 'also' in both HK and GB English. The study aims to ascertain whether HK English exhibits a greater 'syntactic freedom,' allowing for a more distant marking relationship with 'also' compared to GB English. The analysis involves a random extraction of 500 samples from both HK and GB English from the GloWbE corpus, forming a dataset (N=1000). Exclusions are made for cases where 'also' functions as an additive conjunct or serves as a copulative adverb, as well as sentences lacking sufficient indication that 'also' functions as a focusing particle. The final dataset comprises 820 tokens, with 416 for GB and 404 for HK, annotated according to the focused constituent and the relative position of ‘also’. Frequency analysis reveals significant differences in the relative position of 'also' and marking relationships between HK and GB English. Regression analysis indicates a preference in HK English for a distant marking relationship between 'also' and its focused constituent. Notably, the subject and other constituents emerge as significant predictors of a distant position for 'also.' Together, these findings underscore the nuanced linguistic dynamics in HK English and contribute to our understanding of language contact. It suggests that future pedagogical practice should consider incorporating the syntactic variation within English varieties, facilitating leaners’ effective communication in diverse English-speaking environments and enhancing their intercultural communication competence.

Keywords: also, Cantonese, English, focus marker, frequency analysis, language contact, logistic regression analysis

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3116 Spatial Direct Numerical Simulation of Instability Waves in Hypersonic Boundary Layers

Authors: Jayahar Sivasubramanian

Abstract:

Understanding laminar-turbulent transition process in hyper-sonic boundary layers is crucial for designing viable high speed flight vehicles. The study of transition becomes particularly important in the high speed regime due to the effect of transition on aerodynamic performance and heat transfer. However, even after many years of research, the transition process in hyper-sonic boundary layers is still not understood. This lack of understanding of the physics of the transition process is a major impediment to the development of reliable transition prediction methods. Towards this end, spatial Direct Numerical Simulations are conducted to investigate the instability waves generated by a localized disturbance in a hyper-sonic flat plate boundary layer. In order to model a natural transition scenario, the boundary layer was forced by a short duration (localized) pulse through a hole on the surface of the flat plate. The pulse disturbance developed into a three-dimensional instability wave packet which consisted of a wide range of disturbance frequencies and wave numbers. First, the linear development of the wave packet was studied by forcing the flow with low amplitude (0.001% of the free-stream velocity). The dominant waves within the resulting wave packet were identified as two-dimensional second mode disturbance waves. Hence the wall-pressure disturbance spectrum exhibited a maximum at the span wise mode number k = 0. The spectrum broadened in downstream direction and the lower frequency first mode oblique waves were also identified in the spectrum. However, the peak amplitude remained at k = 0 which shifted to lower frequencies in the downstream direction. In order to investigate the nonlinear transition regime, the flow was forced with a higher amplitude disturbance (5% of the free-stream velocity). The developing wave packet grows linearly at first before reaching the nonlinear regime. The wall pressure disturbance spectrum confirmed that the wave packet developed linearly at first. The response of the flow to the high amplitude pulse disturbance indicated the presence of a fundamental resonance mechanism. Lower amplitude secondary peaks were also identified in the disturbance wave spectrum at approximately half the frequency of the high amplitude frequency band, which would be an indication of a sub-harmonic resonance mechanism. The disturbance spectrum indicates, however, that fundamental resonance is much stronger than sub-harmonic resonance.

Keywords: boundary layer, DNS, hyper sonic flow, instability waves, wave packet

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3115 Evaluation of Airborne Particulate Matter Early Biological Effects in Children with Micronucleus Cytome Assay: The MAPEC_LIFE Project

Authors: E. Carraro, Sa. Bonetta, Si. Bonetta, E. Ceretti, G. C. V. Viola, C. Pignata, S. Levorato, T. Salvatori, S. Vannini, V. Romanazzi, A. Carducci, G. Donzelli, T. Schilirò, A. De Donno, T. Grassi, S. Bonizzoni, A. Bonetti, G. Gilli, U. Gelatti

Abstract:

In 2013, air pollution and particulate matter were classified as carcinogenic to human by the IARC. At present, PM is Europe's most problematic pollutant in terms of harm to health, as reported by European Environmental Agency (EEA) in the EEA Technical Report on Air quality in Europe, 2015. A percentage between 17-30 of the EU urban population lives in areas where the EU air quality 24-hour limit value for PM10 is exceeded. Many studies have found a consistent association between exposure to PM and the incidence and mortality for some chronic diseases (i.e. lung cancer, cardiovascular diseases). Among the mechanisms responsible for these adverse effects, genotoxic damage is of particular concern. Children are a high-risk group in terms of the health effects of air pollution and early exposure during childhood can increase the risk of developing chronic diseases in adulthood. The MAPEC_LIFE (Monitoring Air Pollution Effects on Children for supporting public health policy) is a project founded by EU Life+ Programme (LIFE12 ENV/IT/000614) which intends to evaluate the associations between air pollution and early biological effects in children and to propose a model for estimating the global risk of early biological effects due to air pollutants and other factors in children. This work is focused on the micronuclei frequency in child buccal cells in association with airborne PM levels taking into account the influence of other factors associated with the lifestyle of children. The micronucleus test was performed in exfoliated buccal cells of 6–8 years old children from 5 Italian towns with different air pollution levels. Data on air quality during the study period were obtained from the Regional Agency for Environmental Protection. A questionnaire administered to children’s parents was used to obtain details on family socio-economic status, children health condition, exposures to other indoor and outdoor pollutants (i.e. passive smoke) and life-style, with particular reference to eating habits. During the first sampling campaign (winter 2014-15) 1315 children were recruited and sampled for Micronuclei test in buccal cells. In the sampling period the levels of the main pollutants and PM10 were, as expected, higher in the North of Italy (PM10 mean values 62 μg/m3 in Torino and 40 μg/m3 in Brescia) than in the other towns (Pisa, Perugia, Lecce). A higher Micronucleus frequency in buccal cells of children was found in Brescia (0.6/1000 cells) than in the other towns (range 0.3-0.5/1000 cells). The statistical analysis underlines a relation of the micronuclei frequency with PM concentrations, traffic level near child residence, and level of education of parents. The results suggest that, in addition to air pollution exposure, some other factors, related to lifestyle or further exposures, may influence micronucleus frequency and cellular response to air pollutants.

Keywords: air pollution, buccal cells, children, micronucleus cytome assay

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3114 Potentiality of the Wind Energy in Algeria

Authors: C. Benoudjafer, M. N. Tandjaoui, C. Benachaiba

Abstract:

The use of kinetic energy of the wind is in full rise in the world and it starts to be known in our country but timidly. One or more aero generators can be installed to produce for example electricity on isolated places or not connected to the electrical supply network. To use the wind as energy source, it is necessary to know first the energy needs for the population and study the wind intensity, speed, frequency and direction.

Keywords: Algeria, renewable energies, wind, wind power, aero-generators, wind energetic potential

Procedia PDF Downloads 428
3113 Effect of Drag Coefficient Models concerning Global Air-Sea Momentum Flux in Broad Wind Range including Extreme Wind Speeds

Authors: Takeshi Takemoto, Naoya Suzuki, Naohisa Takagaki, Satoru Komori, Masako Terui, George Truscott

Abstract:

Drag coefficient is an important parameter in order to correctly estimate the air-sea momentum flux. However, The parameterization of the drag coefficient hasn’t been established due to the variation in the field data. Instead, a number of drag coefficient model formulae have been proposed, even though almost all these models haven’t discussed the extreme wind speed range. With regards to such models, it is unclear how the drag coefficient changes in the extreme wind speed range as the wind speed increased. In this study, we investigated the effect of the drag coefficient models concerning the air-sea momentum flux in the extreme wind range on a global scale, comparing two different drag coefficient models. Interestingly, one model didn’t discuss the extreme wind speed range while the other model considered it. We found that the difference of the models in the annual global air-sea momentum flux was small because the occurrence frequency of strong wind was approximately 1% with a wind speed of 20m/s or more. However, we also discovered that the difference of the models was shown in the middle latitude where the annual mean air-sea momentum flux was large and the occurrence frequency of strong wind was high. In addition, the estimated data showed that the difference of the models in the drag coefficient was large in the extreme wind speed range and that the largest difference became 23% with a wind speed of 35m/s or more. These results clearly show that the difference of the two models concerning the drag coefficient has a significant impact on the estimation of a regional air-sea momentum flux in an extreme wind speed range such as that seen in a tropical cyclone environment. Furthermore, we estimated each air-sea momentum flux using several kinds of drag coefficient models. We will also provide data from an observation tower and result from CFD (Computational Fluid Dynamics) concerning the influence of wind flow at and around the place.

Keywords: air-sea interaction, drag coefficient, air-sea momentum flux, CFD (Computational Fluid Dynamics)

Procedia PDF Downloads 369
3112 Prevalence and Determinants of Hypertension among the Santal Indigenous Group in Bangladesh

Authors: Sharmin Sultana, Palash Chandra Banik, Shirin Jahan Mumu, Liaquat Ali

Abstract:

Santals are one of the oldest indigenous groups of South Asia who, according to anthropological evidence, are thought to be the origins of the Bengali race. The aim of the study was to explore, according to our best knowledge for the first time, the prevalence and determinants of hypertension in this relatively isolated and marginalized indigenous group who still live mostly in a traditional style. Under a cross-sectional analytical design, the study was conducted on the adult (age≥18 years) Santals (n=389, M/F 184/205, age in years, 38±15.3) of a village located in a remote rural area of northern Bangladesh. Subjects were selected by purposive sampling, and data were collected by interviewer-administered pretested questionnaire. Blood pressure was measured by following the WHO guideline of JNC-7 has been used to classify the blood pressure. The prevalence of hypertension was 4.9% among the respondents. Females had a much higher prevalence (5.4%) of hypertension compared to males (4.3%). Among the risk indicators of hypertension, more than half (50.9%) of the study population took extra salt in their meals, whereas 10.5% of respondents used extra salt occasionally, which is an important risk factor for high blood pressure. High waist circumference was found in 19% of the study subjects in terms of central obesity. Older age group (p=0.003, OR=1.1, 95%CI-1.02-1.10), respondents who completed more than primary school (p=0.038, OR=7.1, CI-1.11, 44.6), overweight and obesity (p=0.004, OR=17.1, CI-2.5, 118.1), were the major determinant for hypertension as found from the binary logistic model. None of the respondents received any medication, neither they visit any doctor ever for their hypertension control. The prevalence of hypertension was found to be low but not ignorable. Pre-hypertension in the case of systolic blood pressure needs attention among Santal indigenous population.

Keywords: hypertension, indigenous group, Santals, Bangladesh

Procedia PDF Downloads 105
3111 StockTwits Sentiment Analysis on Stock Price Prediction

Authors: Min Chen, Rubi Gupta

Abstract:

Understanding and predicting stock market movements is a challenging problem. It is believed stock markets are partially driven by public sentiments, which leads to numerous research efforts to predict stock market trend using public sentiments expressed on social media such as Twitter but with limited success. Recently a microblogging website StockTwits is becoming increasingly popular for users to share their discussions and sentiments about stocks and financial market. In this project, we analyze the text content of StockTwits tweets and extract financial sentiment using text featurization and machine learning algorithms. StockTwits tweets are first pre-processed using techniques including stopword removal, special character removal, and case normalization to remove noise. Features are extracted from these preprocessed tweets through text featurization process using bags of words, N-gram models, TF-IDF (term frequency-inverse document frequency), and latent semantic analysis. Machine learning models are then trained to classify the tweets' sentiment as positive (bullish) or negative (bearish). The correlation between the aggregated daily sentiment and daily stock price movement is then investigated using Pearson’s correlation coefficient. Finally, the sentiment information is applied together with time series stock data to predict stock price movement. The experiments on five companies (Apple, Amazon, General Electric, Microsoft, and Target) in a duration of nine months demonstrate the effectiveness of our study in improving the prediction accuracy.

Keywords: machine learning, sentiment analysis, stock price prediction, tweet processing

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3110 Assessment Using Copulas of Simultaneous Damage to Multiple Buildings Due to Tsunamis

Authors: Yo Fukutani, Shuji Moriguchi, Takuma Kotani, Terada Kenjiro

Abstract:

If risk management of the assets owned by companies, risk assessment of real estate portfolio, and risk identification of the entire region are to be implemented, it is necessary to consider simultaneous damage to multiple buildings. In this research, the Sagami Trough earthquake tsunami that could have a significant effect on the Japanese capital region is focused on, and a method is proposed for simultaneous damage assessment using copulas that can take into consideration the correlation of tsunami depths and building damage between two sites. First, the tsunami inundation depths at two sites were simulated by using a nonlinear long-wave equation. The tsunamis were simulated by varying the slip amount (five cases) and the depths (five cases) for each of 10 sources of the Sagami Trough. For each source, the frequency distributions of the tsunami inundation depth were evaluated by using the response surface method. Then, Monte-Carlo simulation was conducted, and frequency distributions of tsunami inundation depth were evaluated at the target sites for all sources of the Sagami Trough. These are marginal distributions. Kendall’s tau for the tsunami inundation simulation at two sites was 0.83. Based on this value, the Gaussian copula, t-copula, Clayton copula, and Gumbel copula (n = 10,000) were generated. Then, the simultaneous distributions of the damage rate were evaluated using the marginal distributions and the copulas. For the correlation of the tsunami inundation depth at the two sites, the expected value hardly changed compared with the case of no correlation, but the damage rate of the ninety-ninth percentile value was approximately 2%, and the maximum value was approximately 6% when using the Gumbel copula.

Keywords: copulas, Monte-Carlo simulation, probabilistic risk assessment, tsunamis

Procedia PDF Downloads 141