Search results for: limited snapshot
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4323

Search results for: limited snapshot

3933 Cooperation of Unmanned Vehicles for Accomplishing Missions

Authors: Ahmet Ozcan, Onder Alparslan, Anil Sezgin, Omer Cetin

Abstract:

The use of unmanned systems for different purposes has become very popular over the past decade. Expectations from these systems have also shown an incredible increase in this parallel. But meeting the demands of the tasks are often not possible with the usage of a single unmanned vehicle in a mission, so it is necessary to use multiple autonomous vehicles with different abilities together in coordination. Therefore the usage of the same type of vehicles together as a swarm is helped especially to satisfy the time constraints of the missions effectively. In other words, it allows sharing the workload by the various numbers of homogenous platforms together. Besides, it is possible to say there are many kinds of problems that require the usage of the different capabilities of the heterogeneous platforms together cooperatively to achieve successful results. In this case, cooperative working brings additional problems beyond the homogeneous clusters. In the scenario presented as an example problem, it is expected that an autonomous ground vehicle, which is lack of its position information, manage to perform point-to-point navigation without losing its way in a previously unknown labyrinth. Furthermore, the ground vehicle is equipped with very limited sensors such as ultrasonic sensors that can detect obstacles. It is very hard to plan or complete the mission for the ground vehicle by self without lost its way in the unknown labyrinth. Thus, in order to assist the ground vehicle, the autonomous air drone is also used to solve the problem cooperatively. The autonomous drone also has limited sensors like downward looking camera and IMU, and it also lacks computing its global position. In this context, it is aimed to solve the problem effectively without taking additional support or input from the outside, just benefiting capabilities of two autonomous vehicles. To manage the point-to-point navigation in a previously unknown labyrinth, the platforms have to work together coordinated. In this paper, cooperative work of heterogeneous unmanned systems is handled in an applied sample scenario, and it is mentioned that how to work together with an autonomous ground vehicle and the autonomous flying platform together in a harmony to take advantage of different platform-specific capabilities. The difficulties of using heterogeneous multiple autonomous platforms in a mission are put forward, and the successful solutions are defined and implemented against the problems like spatially distributed tasks planning, simultaneous coordinated motion, effective communication, and sensor fusion.

Keywords: unmanned systems, heterogeneous autonomous vehicles, coordination, task planning

Procedia PDF Downloads 128
3932 Environmental /Occupational Factors and Seasonality of Birth- Male Infertility

Authors: C. Lalitha, R. Sayee, D. Apoorva

Abstract:

Reproductive failure or infertility may be due to several factors that are not limited to one sex. It remains a common problem causing significant psychological distress to those affected individuals and who are increasingly seeking medical advice. Male infertility means inability to induce conception in normal woman within a year. The etiological factors associated with male infertility are anatomical, developmental, seminal, hormonal, immunological and environmental factors. The paper was aimed to highlight the environmental factors and its association to male infertility and seasonality of birth and its influence. The data was collected from the 75 male patients referred with infertility for karyotyping and counseling. Their age ranged from 21 to 45 years. It is opined that certain occupations are preferentially associated with male infertility.

Keywords: environmental, occupational, seasonal, male infertility

Procedia PDF Downloads 267
3931 A Hybrid Multi-Objective Firefly-Sine Cosine Algorithm for Multi-Objective Optimization Problem

Authors: Gaohuizi Guo, Ning Zhang

Abstract:

Firefly algorithm (FA) and Sine Cosine algorithm (SCA) are two very popular and advanced metaheuristic algorithms. However, these algorithms applied to multi-objective optimization problems have some shortcomings, respectively, such as premature convergence and limited exploration capability. Combining the privileges of FA and SCA while avoiding their deficiencies may improve the accuracy and efficiency of the algorithm. This paper proposes a hybridization of FA and SCA algorithms, named multi-objective firefly-sine cosine algorithm (MFA-SCA), to develop a more efficient meta-heuristic algorithm than FA and SCA.

Keywords: firefly algorithm, hybrid algorithm, multi-objective optimization, sine cosine algorithm

Procedia PDF Downloads 169
3930 Emerging Barriers And Enablers Of Digital Inclusion For Students With Disabilities In Ethiopian Education

Authors: Merih Welay Welesilassie

Abstract:

This research investigated the factors influencing digital inclusion for young students with disabilities in Ethiopian schools. In this context, socio-economic, infrastructural, and cultural challenges amplify educational disparities. In the era of digital technology's pivotal role in education, it is crucial to ensure equitable access for students with disabilities. Nevertheless, obstacles like inadequate infrastructure, insufficient teacher training, and economic constraints impede the incorporation of digital tools in educational environments, especially for marginalised groups. This study employed an explanatory sequential mixed-methods approach involving data collection through a survey administered to 300 students. Subsequently, in-depth interviews were conducted with 30 participants to provide comprehensive insights into their experiences. The quantitative analysis uncovered that students with disabilities have limited support for digital readiness, find digital technologies less accessible, and perceive digital tools as less easy to use. The study revealed that economic barriers, such as the high cost of devices and limited internet access, prevent students from fully utilising digital resources. Furthermore, infrastructural challenges, such as unreliable electricity and poor internet connectivity, exacerbate the issue. The qualitative data provided a more profound understanding by emphasising social and attitudinal obstacles, including a lack of empathy from both peers and educators, exclusion from participatory digital tasks, and enduring negative stereotypes regarding disabilities. The research highlights the importance of implementing interventions to enhance digital accessibility for students with disabilities. Essential suggestions encompass refining teacher training programs to effectively facilitate inclusive education, improving digital infrastructure, and offering financial assistance to procure digital tools. Furthermore, implementing policy reforms and public awareness campaigns is crucial to cultivate a cultural shift and nurture a more inclusive societal atmosphere. This study yields valuable perspectives on the digital inclusion scenario in Ethiopia, laying the groundwork for prospective research endeavours to narrow the digital gap for students with disabilities.

Keywords: digital inclussion, students with disabilities, ethiopian education, barries and access

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3929 Between a Rock and a Hard Place: The Impact of Inflation on Global Supply Chains

Authors: Elad Harison

Abstract:

The paper identifies the complex links between post-COVID-19 inflationary pressures and global supply chains. Throughout the COVID-19 lockdowns and long periods after the termination of social distancing policies, consumers, notably in the U.S., have confronted and still face disruptions in the supply of goods. The study analyzes the monetary policy in the U.S. that led to the significant shift in consumer demand during a limited supply period, hence resulting in shortages and emphasizing inflationary dynamics. We argue that the monetary guidelines applied by the U.S. government further elevated the scope of supply chain disruptions.

Keywords: consumer demand, COVID-19, inflation, monetary policy, supply chain

Procedia PDF Downloads 92
3928 Dual Band Shared Aperture Antenna for 5G Communications

Authors: Zunnurain Ahmad

Abstract:

This work presents design of a dual band antenna for the 5G communications in the millimeter wave band. As opposed to conventional patch antennas which are limited to single narrow band operation a shared aperture concept is utilized for this antenna. The patch aperture is coupled through two rectangular slots etched on a thin printed circuit board (100μm). The patch is elevated in air thus avoiding excitation of surface waves and minimizing dielectric losses at millimeter wave frequencies. With this approach the radiator can cover lower band of 28 GHz and upper band of 37/ 39 GHz dedicated for the fifth generation communications. The simulated radiation efficiency of the antenna stays above 90%.

Keywords: antenna, millimeter wave, 5G, 3D

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3927 Burnout among Healthcare Workers in Poland during the COVID-19 Pandemic

Authors: Zbigniew Izdebski, Alicja Kozakiewicz, Maciej Białorudzki, Joanna Mazur

Abstract:

Work is an extremely important part of everyone's life and affects functioning in daily life. Healthcare workers (HCW) are suffering from negative actions in and out of the workplace, such as harassment, abuse, long working hours, mental suffering, exhaustion, and professional burnout. Staff burnout is detrimental not only in terms of individual employees but also to working with patients and to the healthcare institution as a whole. The purpose of this study was to explore the level of professional burnout among HCW working in medical institutions during the COVID-19 pandemic in Poland. The extent to which selected sociodemographic factors and perceived stress increase the risk of professional burnout was assessed. In addition, the frequency of use of professional psychological help and less formal support groups by HCW in relation to the level of professional burnout was presented. The survey was conducted as part of a larger project on the humanization of medicine and clinical communication from February-April 2022. This study used a self-administered online survey (CAWI) technique and PAPI (pen and paper interview) technique. The BAT-12 scale was used to measure burnout, the PSS-4 scale was used to measure stress, and questions formulated by the research team were also used. For the purpose of analysis, the sample was limited to 2196 HCWs who worked on a daily basis with patients during the COVID-19 pandemic. Frequency distributions were analyzed, and multivariate logistic regression was performed. The mean scores (scores) of job burnout as measured by the BAT-12 scale ranged among the professional groups from 2.15(0.69) to 2.30 (0.69) and remained highest for the nurses' group. The groups differed significantly in levels of burnout (chi-sq=17.719; d.f.=8; p<0.023). In the final model, raised stress most likely increased the risk of burnout (OR=3.88; 95%CI <3.13-3.81>; p<0,001). Other significant predictors of burnout included: traumatic work-related experience (OR=1.91, p<0.001), mobbing (OR=1.83, p<0.001), and a higher workload than before the pandemic (OR=1.41, p=0.002). Only 7% of respondents decided to use various forms of psychological support during the pandemic. HCW experiences challenges in dealing with an unpredictable pandemic. Limited preparedness can lead to physical and psychological problems such as high-stress levels, anxiety, fear, helplessness, hopelessness, anger and stigma. The workload can lead to professional burnout, as well as threaten patient safety.

Keywords: burnout, work, healthcare, healthcare worker, stress

Procedia PDF Downloads 80
3926 Angiopermissive Foamed and Fibrillar Scaffolds for Vascular Graft Applications

Authors: Deon Bezuidenhout

Abstract:

Pre-seeding with autologous endothelial cells improves the long-term patency of synthetic vascular grafts levels obtained with autografts, but is limited to a single centre due to resource, time and other constraints. Spontaneous in vivo endothelialization would obviate the need for pre-seeding, but has been shown to be absent in man due to limited transanastomotic and fallout healing, and the lack of transmural ingrowth due to insufficient porosity. Two types of graft scaffolds with increased interconnected porosity for improved tissue ingrowth and healing are thus proposed and described. Foam-type polyurethane (PU) scaffolds with small, medium and large, interconnected pores were made by phase inversion and spherical porogen extraction, with and without additional surface modification with covalently attached heparin and subsequent loading with and delivery of growth factors. Fibrillar scaffolds were made either by standard electrospinning using degradable PU (Degrapol®), or by dual electrospinning using non-degradable PU. The latter process involves sacrificial fibres that are co-spun with structural fibres and subsequently removed to increased porosity and pore size. Degrapol samples were subjected to in vitro degradation, and all scaffold types were evaluated in vivo for tissue ingrowth and vascularization using rat subcutaneous model. The foam scaffolds were additionally evaluated in a circulatory (rat infrarenal aortic interposition) model that allows for the grafts to be anastomotically and/or ablumenally isolated to discern and determine endothelialization mode. Foam-type grafts with large (150 µm) pores showed improved subcutaneous healing in terms of vascularization and inflammatory response over smaller pore sizes (60 and 90µm), and vascularization of the large porosity scaffolds was significantly increased by more than 70% by heparin modification alone, and by 150% to 400% when combined with growth factors. In the circulatory model, extensive transmural endothelialization (95±10% at 12 w) was achieved. Fallout healing was shown to be sporadic and limited in groups that were ablumenally isolated to prevent transmural ingrowth (16±30% wrapped vs. 80±20% control; p<0.002). Heparinization and GF delivery improved both mural vascularization and lumenal endothelialization. Degrapol electrospun scaffolds showed decrease in molecular mass and corresponding tensile strength over the first 2 weeks, but very little decrease in mass over the 4w test period. Studies on the effect of tissue ingrowth with and without concomitant degradation of the scaffolds, are being used to develop material models for the finite element modelling. In the case of the dual-spun scaffolds, the PU fibre fraction could be controlled shown to vary linearly with porosity (P = −0.18FF +93.5, r2=0.91), which in turn showed inverse linear correlation with tensile strength and elastic modulus (r2 > 0.96). Calculated compliance and burst pressures of the scaffolds increased with fibre fraction, and compliances matching the human popliteal artery (5-10 %/100 mmHg), and high burst pressures (> 2000 mmHg) could be achieved. Increasing porosity (76 to 82 and 90%) resulted in increased tissue ingrowth from 33±7 to 77±20 and 98±1% after 28d. Transmural endothelialization of highly porous foamed grafts is achievable in a circulatory model, and the enhancement of porosity and tissue ingrowth may hold the key the development of spontaneously endothelializing electrospun grafts.

Keywords: electrospinning, endothelialization, porosity, scaffold, vascular graft

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3925 Psychosocial Support in Disaster Situations in the Philippines and Indonesia: A Critical Literature Review

Authors: Fuad Hamsyah

Abstract:

Since last two decades, major disasters have happened in the Philippines and Indonesia as two countries that are located in the pacific ring of fire territory. While in Southeast Asian countries, the process of psychosocial support provision is facing various constraints such as limited number of mental health professionals and the limited knowledge about the provision of psychosocial support for disaster survivors. Yet after the tsunami disaster in 2004, many Asian countries begin to develop policies about the provision of psychosocial interventions as an effort for future disasters preparedness. In addition, mental health professionals have to consider the local cultural values and beliefs in order to provide people with effective psychosocial support since cultural values and beliefs play a significant role in the diversity of psychological distress that forms symptoms formation, and people’s way to seek for psychological assistance. This study is a critical literature review on 130 relevant selected documents and literatures. IASC MHPSS guideline is used as the research framework in doing critical analysis. The purpose of this study is to conduct a critical analysis on the mental health and psychosocial support provision in the Philippines and Indonesia with three main objectives: 1) To describe strengths, weaknesses, and challenges in the process of psychosocial supports given by public and private organizations in emergency settings of disaster in the Philippines and Indonesia, 2) To compare psychosocial support practices between the Philippines and Indonesia, and to identify the good practices among these countries, 3) To learn how cultural values influence the implementation of psychosocial supports in emergency settings of disaster. This research indicated that almost every function from IASC MHPSS guidelines has been implemented effectively in the Philippines and Indonesia, yet not in every detail of IASC MHPSS guidelines. Several similarities and differences are indicated in this study also based on the IASC MHPSS guidelines as the analysis framework. Further, both countries have some good practices that can be useful as an example of a comprehensive psychosocial support implementation. Apart from the IASC MHPSS guideline, cultural values and beliefs in the Philippines such as kanya-kanya syndrome, pakikipakapwa, utang na loob, bahala na, pagkaya are indicated as several cultural values that have strong influences towards people’s attitude and behavior in disaster situations. While in Indonesia, several cultural values such as sabar and nrimo become two important attitudes to cope disaster situations.

Keywords: disaster, Indonesia, psychosocial support, Philippines

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3924 Impact of Pediatric Cardiac Rehabilitation on the Physical Condition of Children with Congenital Heart Defects

Authors: Hady Atef Labib

Abstract:

Pediatric cardiac rehabilitation has the potential to benefit many children with congenital heart defects (CHD). Instead of excellent surgical results most of children usually present with a depression of physical condition so early rehabilitation program is recommended to avoid that decline in physical tolerance and prevent any post surgical complications. Unfortunately, the limited experience with and availability of these programs has caused the benefits of cardiac rehabilitation to be unavailable to most children with CHD. Therefore, it is recommended to study that field in more detail and apply it on wider scale.

Keywords: pediatric cardiac rehabilitation, congenital heart disease, quality of life, pediatric

Procedia PDF Downloads 378
3923 The Impact of External Technology Acquisition and Exploitation on Firms' Process Innovation Performance

Authors: Thammanoon Charmjuree, Yuosre F. Badir, Umar Safdar

Abstract:

There is a consensus among innovation scholars that knowledge is a vital antecedent for firm’s innovation; e.g., process innovation. Recently, there has been an increasing amount of attention to more open approaches to innovation. This open model emphasizes the use of purposive flows of knowledge across the organization boundaries. Firms adopt open innovation strategy to improve their innovation performance by bringing knowledge into the organization (inbound open innovation) to accelerate internal innovation or transferring knowledge outside (outbound open innovation) to expand the markets for external use of innovation. Reviewing open innovation research reveals the following. First, the majority of existing studies have focused on inbound open innovation and less on outbound open innovation. Second, limited research has considered the possible interaction between both and how this interaction may impact the firm’s innovation performance. Third, scholars have focused mainly on the impact of open innovation strategy on product innovation and less on process innovation. Therefore, our knowledge of the relationship between firms’ inbound and outbound open innovation and how these two impact process innovation is still limited. This study focuses on the firm’s external technology acquisition (ETA) and external technology exploitation (ETE) and the firm’s process innovation performance. The ETA represents inbound openness in which firms rely on the acquisition and absorption of external technologies to complement their technology portfolios. The ETE, on the other hand, refers to commercializing technology assets exclusively or in addition to their internal application. This study hypothesized that both ETA and ETE have a positive relationship with process innovation performance and that ETE fully mediates the relationship between ETA and process innovation performance, i.e., ETA has a positive impact on ETE, and turn, ETE has a positive impact on process innovation performance. This study empirically explored these hypotheses in software development firms in Thailand. These firms were randomly selected from a list of Software firms registered with the Department of Business Development, Ministry of Commerce of Thailand. The questionnaires were sent to 1689 firms. After follow-ups and periodic reminders, we obtained 329 (19.48%) completed usable questionnaires. The structure question modeling (SEM) has been used to analyze the data. An analysis of the outcome of 329 firms provides support for our three hypotheses: First, the firm’s ETA has a positive impact on its process innovation performance. Second, the firm’s ETA has a positive impact its ETE. Third, the firm’s ETE fully mediates the relationship between the firm’s ETA and its process innovation performance. This study fills up the gap in open innovation literature by examining the relationship between inbound (ETA) and outbound (ETE) open innovation and suggest that in order to benefits from the promises of openness, firms must engage in both. The study went one step further by explaining the mechanism through which ETA influence process innovation performance.

Keywords: process innovation performance, external technology acquisition, external technology exploitation, open innovation

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3922 Solar Energy Technology Adoption; A Vignette Study for the Up-Scale Residential Sector in Egypt

Authors: Mazen Zaki, Sherwat E. Ibrahim

Abstract:

Renewable energy has become a very important and critical topic all around the world due to the limited resources that led to shifting to the trend of renewable energy and its integration with the conventional ones. This paper investigates the adoption of the solar energy technology for up-scale residential sector in Cairo, Egypt. The technology acceptance model uses several stakeholder points’ of views to develop vignettes to be used in examining the intention and attitude of the householders to adopt the solar energy technology.

Keywords: solar energy, technology acceptance model, TAM, stakeholder analysis, vignette, residential sector

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3921 Ni-B Coating Production on Magnesium Alloy by Electroless Deposition

Authors: Ferhat Bülbül

Abstract:

The use of magnesium alloys is limited due to their susceptibility to corrosion although they have many attractive physical and mechanical properties. To increase mechanical and corrosion properties of these alloys, many deposition method and coating types are used. Electroless Ni–B coatings have received considerable interest recently due to its unique properties such as cost-effectiveness, thickness uniformity, good wear resistance, lubricity, good ductility and corrosion resistance, excellent solderability and electrical properties and antibacterial property. In this study, electroless Ni-B coating could been deposited on AZ91 magnesium alloy. The obtained coating exhibited an amorphous and rougher structure.

Keywords: magnesium, electroless Ni–B, X-ray diffraction, amorphous

Procedia PDF Downloads 340
3920 A609 Modeling of AC Servomotor Using Genetic Algorithm and Tests for Control of a Robotic Joint

Authors: J. G. Batista, T. S. Santiago, E. A. Ribeiro, G. A. P. Thé

Abstract:

This work deals with parameter identification of permanent magnet motors, a class of ac motor which is particularly important in industrial automation due to characteristics like applications high performance, are very attractive for applications with limited space and reducing the need to eliminate because they have reduced size and volume and can operate in a wide speed range, without independent ventilation. By using experimental data and genetic algorithm we have been able to extract values for both the motor inductance and the electromechanical coupling constant, which are then compared to measure and/or expected values.

Keywords: modeling, AC servomotor, permanent magnet synchronous motor-PMSM, genetic algorithm, vector control, robotic manipulator, control

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3919 Unmanned Aerial Vehicle Use for Emergency Purpose

Authors: Shah S. M. A., Aftab U.

Abstract:

It is imperative in today’s world to get a real time information about different emergency situation occurred in the environment. Helicopters are mostly used to access places which are hard to access in emergencies like earthquake, floods, bridge failure or in any other disasters conditions. Use of helicopters are considered more costly to properly collect the data. Therefore a new technique has been introduced in this research to promptly collect data using drones. The drone designed in this research is based on trial and error experimental work with objective to construct an economical drone. Locally available material have been used for this purpose. And a mobile camera were also attached to prepare video during the flight. It was found that within very limited resources the result were quite successful.

Keywords: UAV, real time, camera, disasters

Procedia PDF Downloads 237
3918 Recovery in Serious Mental Illness: Perception of Health Care Trainees in Morocco

Authors: Sophia El Ouazzani, Amer M. Burhan, Mary Wickenden

Abstract:

Background: Despite improvements in recent years, the Moroccan mental healthcare system still face disparity between available resources and the current population’sneeds. The societal stigma, and limited economic, political, and human resources are all factors in shaping the psychiatric system, exacerbating the discontinuity of services for users after discharged from the hospital. As a result, limited opportunities for social inclusion and meaningful community engagement undermines human rights and recovery potential for people with mental health problems, especially those with psychiatric disabilities from serious mental illness (SMI). Recovery-oriented practice, such as mental health rehabilitation, addresses the complex needs of patients with SMI and support their community inclusion. The cultural acceptability of recovery-oriented practice is an important notion to consider for a successful implementation. Exploring the extent to which recovery-oriented practices are used in Morocco is a necessary first step to assess the cultural relevance of such a practice model. Aims: This study aims to explore understanding and knowledge, perception, and perspective about core concepts in mental health rehabilitation, including psychiatric disability, recovery, and engagement in meaningful occupations for people with SMI in Morocco. Methods: A pilot qualitative study was undertaken. Data was collected via semi-structured interviews and focusgroup discussions with healthcare professional students. Questions were organised around the following themes: 1) students’ perceptions, understanding, and expectations around concepts such as SMI, mental health disability, and recovery, and 2) changes in their views and expectations after starting their professional training. Further analysis of students’ perspectives on the concept of ‘meaningful occupation’ and how is this viewed within the context of the research questions was done. The data was extracted using an inductive thematic analysis approach. This is a pilot stage of a doctoral project, further data will be collected and analysed until saturation is reached. Results: A total of eight students were included in this study which included occupational therapy and mental health nursing students receiving training in Morocco. The following themes emerged as influencing students’ perceptions and views around the main concepts: 1) Stigma and discrimination, 2) Fatalism and low expectations, 3) Gendered perceptions, 4) Religious causation, 5) Family involvement, 6) Professional background, 7) Inaccessibility of services and treatment. Discussion/Contribution: Preliminary analysis of the data suggests that students’ perceptions changed after gaining more clinical experiences and being exposed to people with psychiatric disabilities. Prior to their training, stigma shaped greatly how they viewed people with SMI. The fear, misunderstanding, and shame around SMI and their functional capacities may contribute to people with SMI being stigmatizedand marginalised from their family and their community. Religious causations associated to SMIsare understood as further deepening the social stigma around psychiatric disability. Perceptions are influenced by gender, with women being doubly discriminated against in relation to recovery opportunities. Therapeutic pessimism seems to persist amongst students and within the mental healthcare system in general and regarding the recovery potential and opportunities for people with SMI. The limited resources, fatalism, and stigma all contribute to the low expectations for recovery and community inclusion. Implications and future directions will be discussed.

Keywords: disability, mental health rehabilitation, recovery, serious mental illness, transcultural psychiatry

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3917 An Algorithm Based on the Nonlinear Filter Generator for Speech Encryption

Authors: A. Belmeguenai, K. Mansouri, R. Djemili

Abstract:

This work present a new algorithm based on the nonlinear filter generator for speech encryption and decryption. The proposed algorithm consists on the use a linear feedback shift register (LFSR) whose polynomial is primitive and nonlinear Boolean function. The purpose of this system is to construct Keystream with good statistical properties, but also easily computable on a machine with limited capacity calculated. This proposed speech encryption scheme is very simple, highly efficient, and fast to implement the speech encryption and decryption. We conclude the paper by showing that this system can resist certain known attacks.

Keywords: nonlinear filter generator, stream ciphers, speech encryption, security analysis

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3916 Comparison of Instantaneous Short Circuit versus Step DC Voltage to Determine PMG Inductances

Authors: Walter Evaldo Kuchenbecker, Julio Carlos Teixeira

Abstract:

Since efficiency became a challenge to reduce energy consumption of all electrical machines applications, the permanent magnet machine raises up as a better option, because its performance, robustness and simple control. Even though, the electrical machine was developed through analyses of magnetism effect, permanent magnet machines still not well dominated. As permanent magnet machines are becoming popular in most applications, the pressure to standardize this type of electrical machine increases. However, due limited domain, it is still nowadays without any standard to manufacture, test and application. In order to determine an inductance of the machine, a new method is proposed.

Keywords: permanent magnet generators (pmg), synchronous machine parameters, test procedures, inductances

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3915 Offshorability and the Lobby for Immigrant Labor

Authors: Ellen A. Holtmaat

Abstract:

Research on lobbying for immigration is limited and the influence of offshorability on lobbying for immigration has not extensively been assessed. This research focuses on the U.S. and argues that offshorable firms have an ‘outside-option’ when they are in need of labor, which makes them less likely to lobby for immigration in the lower-skilled sectors. Higher-skilled offshorable sectors settle often in the U.S., as the U.S. has a comparative advantage in these sectors. The companies compete globally and demand world’s best labor, which induces them to lobby for immigration. This relationship is assessed using lobby data available from the 1995 Lobby Disclosure Act. Some evidence of the relationship is found and the research suggests that offshorability might also in general influence lobbying.

Keywords: immigration, lobbying, non-tradable sector, offshoring

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3914 Cancer Burden and Policy Needs in the Democratic Republic of the Congo: A Descriptive Study

Authors: Jean Paul Muambangu Milambo, Peter Nyasulu, John Akudugu, Leonidas Ndayisaba, Joyce Tsoka-Gwegweni, Lebwaze Massamba Bienvenu, Mitshindo Mwambangu Chiro

Abstract:

In 2018, non-communicable diseases (NCDs) were responsible for 48% of deaths in the Democratic Republic of Congo (DRC), with cancer contributing to 5% of these deaths. There is a notable absence of cancer registries, capacity-building activities, budgets, and treatment roadmaps in the DRC. Current cancer estimates are primarily based on mathematical modeling with limited data from neighboring countries. This study aimed to assess cancer subtype prevalence in Kinshasa hospitals and compare these findings with WHO model estimates. Methods: A retrospective observational study was conducted from 2018 to 2020 at HJ Hospitals in Kinshasa. Data were collected using American Cancer Society (ACS) questionnaires and physician logs. Descriptive analysis was performed using STATA version 16 to estimate cancer burden and provide evidence-based recommendations. Results: The results from the chart review at HJ Hospitals in Kinshasa (2018-2020) indicate that out of 6,852 samples, approximately 11.16% were diagnosed with cancer. The distribution of cancer subtypes in this cohort was as follows: breast cancer (33.6%), prostate cancer (21.8%), colorectal cancer (9.6%), lymphoma (4.6%), and cervical cancer (4.4%). These figures are based on histopathological confirmation at the facility and may not fully represent the broader population due to potential selection biases related to geographic and financial accessibility to the hospital. In contrast, the World Health Organization (WHO) model estimates for cancer prevalence in the DRC show different proportions. According to WHO data, the distribution of cancer types is as follows: cervical cancer (15.9%), prostate cancer (15.3%), breast cancer (14.9%), liver cancer (6.8%), colorectal cancer (5.9%), and other cancers (41.2%) (WHO, 2020). Conclusion: The data indicate a rising cancer prevalence in DRC but highlight significant gaps in clinical, biomedical, and genetic cancer data. The establishment of a population-based cancer registry (PBCR) and a defined cancer management pathway is crucial. The current estimates are limited due to data scarcity and inconsistencies in clinical practices. There is an urgent need for multidisciplinary cancer management, integration of palliative care, and improvement in care quality based on evidence-based measures.

Keywords: cancer, risk factors, DRC, gene-environment interactions, survivors

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3913 Review of Modern Gas turbine Blade Cooling Technologies used in Aircraft

Authors: Arun Prasath Subramanian

Abstract:

The turbine Inlet Temperature is an important parameter which determines the efficiency of a gas turbine engine. The increase in this parameter is limited by material constraints of the turbine blade.The modern Gas turbine blade has undergone a drastic change from a simple solid blade to a modern multi-pass blade with internal and external cooling techniques. This paper aims to introduce the reader the concept of turbine blade cooling, the classification of techniques and further explain some of the important internal cooling technologies used in a modern gas turbine blade along with the various factors that affect the cooling effectiveness.

Keywords: gas turbine blade, cooling technologies, internal cooling, pin-fin cooling, jet impingement cooling, rib turbulated cooling, metallic foam cooling

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3912 Urban and Rural Population Pyramids in Georgia Since 1950’s

Authors: Shorena Tsiklauri, Avtandil Sulaberidze, Nino Gomelauri

Abstract:

In the years followed independence, an economic crisis and some conflicts led to the displacement of many people inside Georgia. The growing poverty, unemployment, low income and its unequal distribution limited access to basic social service have had a clear direct impact on Georgian population dynamics and its age-sex structure. Factors influencing the changing population age structure and urbanization include mortality, fertility, migration and expansion of urban. In this paper presents the main factors of changing the distribution by urban and rural areas. How different are the urban and rural age and sex structures? Does Georgia have the same age-sex structure among their urban and rural populations since 1950s?

Keywords: age and sex structure of population, georgia, migration, urban-rural population

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3911 Motorist Driving Strategy-Related Factors Affecting Vehicle Fuel Efficiency

Authors: Aydin Azizi, Abdurrahman Tanira

Abstract:

With the onset of climate change and limited fuel resources, improving fuel efficiency has become an important part of the motor industry. To maximize fuel efficiency, development of technologies must come hand-in-hand with awareness of efficient driving strategies. This study aims to explore the various driving habits that can impact fuel efficiency by reviewing available literature. Such habits include sudden and unnecessary acceleration or deceleration, improper hardware maintenance, driving above or below optimum speed and idling. By studying such habits and ultimately applying it to driving techniques, in combination with improved mechanics of the car, will optimize the use of fuel.

Keywords: fuel efficiency, driving techniques, optimum speed, optimizing fuel consumption

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3910 CFD Modeling of Stripper Ash Cooler of Circulating Fluidized Bed

Authors: Ravi Inder Singh

Abstract:

Due to high heat transfer rate, high carbon utilizing efficiency, fuel flexibilities and other advantages numerous circulating fluidized bed boilers have grown up in India in last decade. Many companies like BHEL, ISGEC, Thermax, Cethar Limited, Enmas GB Power Systems Projects Limited are making CFBC and installing the units throughout the India. Due to complexity many problems exists in CFBC units and only few have been reported. Agglomeration i.e clinker formation in riser, loop seal leg and stripper ash coolers is one of problem industry is facing. Proper documentation is rarely found in the literature. Circulating fluidized bed (CFB) boiler bottom ash contains large amounts of physical heat. While the boiler combusts the low-calorie fuel, the ash content is normally more than 40% and the physical heat loss is approximately 3% if the bottom ash is discharged without cooling. In addition, the red-hot bottom ash is bad for mechanized handling and transportation, as the upper limit temperature of the ash handling machinery is 200 °C. Therefore, a bottom ash cooler (BAC) is often used to treat the high temperature bottom ash to reclaim heat, and to have the ash easily handled and transported. As a key auxiliary device of CFB boilers, the BAC has a direct influence on the secure and economic operation of the boiler. There are many kinds of BACs equipped for large-scale CFB boilers with the continuous development and improvement of the CFB boiler. These ash coolers are water cooled ash cooling screw, rolling-cylinder ash cooler (RAC), fluidized bed ash cooler (FBAC).In this study prototype of a novel stripper ash cooler is studied. The Circulating Fluidized bed Ash Coolers (CFBAC) combined the major technical features of spouted bed and bubbling bed, and could achieve the selective discharge on the bottom ash. The novel stripper ash cooler is bubbling bed and it is visible cold test rig. The reason for choosing cold test is that high temperature is difficult to maintain and create in laboratory level. The aim of study to know the flow pattern inside the stripper ash cooler. The cold rig prototype is similar to stripper ash cooler used industry and it was made after scaling down to some parameter. The performance of a fluidized bed ash cooler is studied using a cold experiment bench. The air flow rate, particle size of the solids and air distributor type are considered to be the key parameters of the operation of a fluidized bed ash cooler (FBAC) are studied in this.

Keywords: CFD, Eulerian-Eulerian, Eulerian-Lagraingian model, parallel simulations

Procedia PDF Downloads 510
3909 Alternative Key Exchange Algorithm Based on Elliptic Curve Digital Signature Algorithm Certificate and Usage in Applications

Authors: A. Andreasyan, C. Connors

Abstract:

The Elliptic Curve Digital Signature algorithm-based X509v3 certificates are becoming more popular due to their short public and private key sizes. Moreover, these certificates can be stored in Internet of Things (IoT) devices, with limited resources, using less memory and transmitted in network security protocols, such as Internet Key Exchange (IKE), Transport Layer Security (TLS) and Secure Shell (SSH) with less bandwidth. The proposed method gives another advantage, in that it increases the performance of the above-mentioned protocols in terms of key exchange by saving one scalar multiplication operation.

Keywords: cryptography, elliptic curve digital signature algorithm, key exchange, network security protocol

Procedia PDF Downloads 146
3908 Combustion Characteristics of Ionized Fuels for Battery System Safety

Authors: Hyeuk Ju Ko, Eui Ju Lee

Abstract:

Many electronic devices are powered by various rechargeable batteries such as lithium-ion today, but occasionally the batteries undergo thermal runaway and cause fire, explosion, and other hazards. If a battery fire should occur in an electronic device of vehicle and aircraft cabin, it is important to quickly extinguish the fire and cool the batteries to minimize safety risks. Attempts to minimize these risks have been carried out by many researchers but the number of study on the successful extinguishment is limited. Because most rechargeable batteries are operated on the ion state with electron during charge and discharge of electricity, and the reaction of this electrolyte has a big difference with normal combustion. Here, we focused on the effect of ions on reaction stability and pollutant emissions during combustion process. The other importance for understanding ionized fuel combustion could be found in high efficient and environment-friendly combustion technologies, which are used to be operated an extreme condition and hence results in unintended flame instability such as extinction and oscillation. The use of electromagnetic energy and non-equilibrium plasma is one of the way to solve the problems, but the application has been still limited because of lack of excited ion effects in the combustion process. Therefore, the understanding of ion role during combustion might be promised to the energy safety society including the battery safety. In this study, the effects of an ionized fuel on the flame stability and pollutant emissions were experimentally investigated in the hydrocarbon jet diffusion flames. The burner used in this experiment consisted of 7.5 mm diameter tube for fuel and the gaseous fuels were ionized with the ionizer (SUNJE, SPN-11). Methane (99.9% purity) and propane (commercial grade) were used as a fuel and open ambient air was used as an oxidizer. As the performance of ionizer used in the experiment was evaluated at first, ion densities of both propane and methane increased linearly with volume flow rate but the ion density of propane is slightly higher than that of methane. The results show that the overall flame stability and shape such as flame length has no significant difference even in the higher ion concentration. However, the fuel ionization affects to the pollutant emissions such as NOx and soot. NOx and CO emissions measured in post flame region decreased with increasing fuel ionization, especially at high fuel velocity, i.e. high ion density. TGA analysis and morphology of soot by TEM indicates that the fuel ionization makes soot to be matured.

Keywords: battery fires, ionization, jet flames, stability, NOx and soot

Procedia PDF Downloads 186
3907 Unified Coordinate System Approach for Swarm Search Algorithms in Global Information Deficit Environments

Authors: Rohit Dey, Sailendra Karra

Abstract:

This paper aims at solving the problem of multi-target searching in a Global Positioning System (GPS) denied environment using swarm robots with limited sensing and communication abilities. Typically, existing swarm-based search algorithms rely on the presence of a global coordinate system (vis-à-vis, GPS) that is shared by the entire swarm which, in turn, limits its application in a real-world scenario. This can be attributed to the fact that robots in a swarm need to share information among themselves regarding their location and signal from targets to decide their future course of action but this information is only meaningful when they all share the same coordinate frame. The paper addresses this very issue by eliminating any dependency of a search algorithm on the need of a predetermined global coordinate frame by the unification of the relative coordinate of individual robots when within the communication range, therefore, making the system more robust in real scenarios. Our algorithm assumes that all the robots in the swarm are equipped with range and bearing sensors and have limited sensing range and communication abilities. Initially, every robot maintains their relative coordinate frame and follow Levy walk random exploration until they come in range with other robots. When two or more robots are within communication range, they share sensor information and their location w.r.t. their coordinate frames based on which we unify their coordinate frames. Now they can share information about the areas that were already explored, information about the surroundings, and target signal from their location to make decisions about their future movement based on the search algorithm. During the process of exploration, there can be several small groups of robots having their own coordinate systems but eventually, it is expected for all the robots to be under one global coordinate frame where they can communicate information on the exploration area following swarm search techniques. Using the proposed method, swarm-based search algorithms can work in a real-world scenario without GPS and any initial information about the size and shape of the environment. Initial simulation results show that running our modified-Particle Swarm Optimization (PSO) without global information we can still achieve the desired results that are comparable to basic PSO working with GPS. In the full paper, we plan on doing the comparison study between different strategies to unify the coordinate system and to implement them on other bio-inspired algorithms, to work in GPS denied environment.

Keywords: bio-inspired search algorithms, decentralized control, GPS denied environment, swarm robotics, target searching, unifying coordinate systems

Procedia PDF Downloads 137
3906 Variable Renewable Energy Droughts in the Power Sector – A Model-based Analysis and Implications in the European Context

Authors: Martin Kittel, Alexander Roth

Abstract:

The continuous integration of variable renewable energy sources (VRE) in the power sector is required for decarbonizing the European economy. Power sectors become increasingly exposed to weather variability, as the availability of VRE, i.e., mainly wind and solar photovoltaic, is not persistent. Extreme events, e.g., long-lasting periods of scarce VRE availability (‘VRE droughts’), challenge the reliability of supply. Properly accounting for the severity of VRE droughts is crucial for designing a resilient renewable European power sector. Energy system modeling is used to identify such a design. Our analysis reveals the sensitivity of the optimal design of the European power sector towards VRE droughts. We analyze how VRE droughts impact optimal power sector investments, especially in generation and flexibility capacity. We draw upon work that systematically identifies VRE drought patterns in Europe in terms of frequency, duration, and seasonality, as well as the cross-regional and cross-technological correlation of most extreme drought periods. Based on their analysis, the authors provide a selection of relevant historical weather years representing different grades of VRE drought severity. These weather years will serve as input for the capacity expansion model for the European power sector used in this analysis (DIETER). We additionally conduct robustness checks varying policy-relevant assumptions on capacity expansion limits, interconnections, and level of sector coupling. Preliminary results illustrate how an imprudent selection of weather years may cause underestimating the severity of VRE droughts, flawing modeling insights concerning the need for flexibility. Sub-optimal European power sector designs vulnerable to extreme weather can result. Using relevant weather years that appropriately represent extreme weather events, our analysis identifies a resilient design of the European power sector. Although the scope of this work is limited to the European power sector, we are confident that our insights apply to other regions of the world with similar weather patterns. Many energy system studies still rely on one or a limited number of sometimes arbitrarily chosen weather years. We argue that the deliberate selection of relevant weather years is imperative for robust modeling results.

Keywords: energy systems, numerical optimization, variable renewable energy sources, energy drought, flexibility

Procedia PDF Downloads 72
3905 Optimization of Black-Litterman Model for Portfolio Assets Allocation

Authors: A. Hidalgo, A. Desportes, E. Bonin, A. Kadaoui, T. Bouaricha

Abstract:

Present paper is concerned with portfolio management with Black-Litterman (B-L) model. Considered stocks are exclusively limited to large companies stocks on US market. Results obtained by application of the model are presented. From analysis of collected Dow Jones stock data, remarkable explicit analytical expression of optimal B-L parameter τ, which scales dispersion of normal distribution of assets mean return, is proposed in terms of standard deviation of covariance matrix. Implementation has been developed in Matlab environment to split optimization in Markovitz sense from specific elements related to B-L representation.

Keywords: Black-Litterman, Markowitz, market data, portfolio manager opinion

Procedia PDF Downloads 260
3904 Acceleration of DNA Hybridization Using Electroosmotic Flow

Authors: Yun-Hsiang Wang, Huai-Yi Chen, Kin Fong Lei

Abstract:

Deoxyribonucleic acid (DNA) hybridization is a common technique used in genetic assay widely. However, the hybridization ratio and rate are usually limited by the diffusion effect. Here, microfluidic electrode platform producing electroosmosis generated by alternating current signal has been proposed to enhance the hybridization ratio and rate. The electrode was made of aurum fabricated by microfabrication technique. Thiol-modified oligo probe was immobilized on the electrode for specific capture of target, which is modified by fluorescent tag. Alternative electroosmosis can induce local microfluidic vortexes to accelerate DNA hybridization. This study provides a strategy to enhance the rate of DNA hybridization in the genetic assay.

Keywords: DNA hybridization, electroosmosis, electrical enhancement, hybridization ratio

Procedia PDF Downloads 383