Search results for: mass rapid transit systems
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 14332

Search results for: mass rapid transit systems

8422 Multi-Criteria Evaluation of IDS Architectures in Cloud Computing

Authors: Elmahdi Khalil, Saad Enniari, Mostapha Zbakh

Abstract:

Cloud computing promises to increase innovation and the velocity with witch applications are deployed, all while helping any enterprise meet most IT service needs at a lower total cost of ownership and higher return investment. As the march of cloud continues, it brings both new opportunities and new security challenges. To take advantages of those opportunities while minimizing risks, we think that Intrusion Detection Systems (IDS) integrated in the cloud is one of the best existing solutions nowadays in the field. The concept of intrusion detection was known since past and was first proposed by a well-known researcher named Anderson in 1980's. Since that time IDS's are evolving. Although, several efforts has been made in the area of Intrusion Detection systems for cloud computing environment, many attacks still prevail. Therefore, the work presented in this paper proposes a multi criteria analysis and a comparative study between several IDS architectures designated to work in a cloud computing environments. To achieve this objective, in the first place we will search in the state of the art of several consistent IDS architectures designed to work in a cloud environment. Whereas, in a second step we will establish the criteria that will be useful for the evaluation of architectures. Later, using the approach of multi criteria decision analysis Mac Beth (Measuring Attractiveness by a Categorical Based Evaluation Technique we will evaluate the criteria and assign to each one the appropriate weight according to their importance in the field of IDS architectures in cloud computing. The last step is to evaluate architectures against the criteria and collecting results of the model constructed in the previous steps.

Keywords: cloud computing, cloud security, intrusion detection/prevention system, multi-criteria decision analysis

Procedia PDF Downloads 453
8421 Sustainability Innovation Capacity Building Framework for UN Sustainable Development Goals

Authors: C. Park, H. Lee, Y-J. Lee

Abstract:

Aim: This study aims to present the Sustainability Innovation Capacity Building Framework (SICBF) to enable the wider public to achieve UN Sustainable Development Goals (UN SDGs) for a sustainable future. The intrinsically interwoven nature of sustainability requires systematic approaches to attain. However, there is a lack of an effective framework for capacity building that enables a systematic implementation approach for UN SDGs. The SICBF illustrates the six core components and their dynamics: 1. Momentum creation; 2. Exposure to diverse worldviews; 3. Serendipity/Eureka moment; 4. Creative problem solving; 5. Individual empowerment; 6. Systems thinking. Method: First, a structured literature review was used to synthesise existing sustainability competencies studies and generic innovation competencies. Secondly, the conceptual framework based on literature findings was tested with the participants' survey and interview data collected from four sets of MAKEathon events. The interview analysis and event observation data were used to further refine and validate the conceptual framework. Contributions: The scientific contribution of this study is to pave the way for SDGs specific capacity building framework that caters to the need for systematic approaches to allow the wider public aspiring to tackle the seemingly intractable sustainable development goals. The framework will aid sustainable development academics, educators, and practitioners in understanding the dynamics of how capacity building can be facilitated.

Keywords: capacity building, sustainability innovation, sustainable development, systems thinking, UN SDGs

Procedia PDF Downloads 58
8420 Vibration Control of Hermetic Compressors Using Flexible Multi-Body Dynamics Theory

Authors: Armin Amindari

Abstract:

Hermetic compressors are used widely for refrigeration, heat pump, and air conditioning applications. With the improvement of energy conservation and environmental protection requirements, inverter compressors that operates at different speeds have become increasingly attractive in the industry. Although speed change capability is more efficient, passing through resonant frequencies may lead to excessive vibrations. In this work, an integrated vibration control approach based on flexible multi-body dynamics theory is used for optimizing the vibration amplitudes of the compressor at different operating speeds. To examine the compressor vibrations, all the forces and moments exerted on the cylinder block were clarified and minimized using balancers attached to the upper and lower ends of the motor rotor and crankshaft. The vibration response of the system was simulated using Motionview™ software. In addition, mass-spring optimization was adopted to shift the resonant frequencies out of the operating speeds. The modal shapes of the system were studied using Optistruct™ solver. Using this approach, the vibrations were reduced up to 56% through dynamic simulations. The results were in high agreement with various experimental test data. In addition, the vibration resonance problem observed at low speeds was solved by shifting the resonant frequencies through optimization studies.

Keywords: vibration, MBD, compressor, hermetic

Procedia PDF Downloads 86
8419 Food Sovereignty as Local Resistance to Unequal Access to Food and Natural Resources in Latin America: A Gender Perspective

Authors: Ana Alvarenga De Castro

Abstract:

Food sovereignty has been brought by the international peasants’ movement, La Via Campesina, as a precondition to food security, speaking about the right of each nation to keep its own supply of foods respecting cultural, sustainable practices and productive diversity. The political conceptualization nowadays goes beyond saying that this term is about achieving the rights of farmers to control the food systems according to local specificities, and about equality in the access to natural resources and quality food. The current feminization of agroecosystems and of food insecurity identified by researchers and recognized by international agencies like the UN and FAO has enhanced the feminist discourse into the food sovereignty movement, considering the historical inequalities that place women farmers in subaltern positions inside the families and rural communities. The current tendency in many rural areas of more women taking responsibility for food production and still facing the lack of access to natural resources meets particular aspects in Latin America due to the global economic logic which places the Global South in the position of raw material supplier for the industrialized North, combined with regional characteristics. In this context, Latin American countries play the role of commodities exporters in the international labor division, including among exported items grains, soybean paste, and ores, to the expense of local food chains which provide domestic quality food supply under more sustainable practices. The connections between gender inequalities and global territorial inequalities related to the access and control of food and natural resources are pointed out by feminist political ecology - FPE - authors, and are linked in this article to the potentialities and limitations of women farmers to reproduce diversified agroecosystems in the tropical environments. The work brings the importance of local practices held by women farmers which are crucial to maintaining sustainable agricultural systems and their results on seeds, soil, biodiversity and water conservation. This work presents an analysis of documents, releases, videos and other publicized experiences launched by some peasants’ organizations in Latin America which evidence the different technical and political answers that meet food sovereignty from peasants’ groups that are attributed to women farmers. They are associated with articles presenting the empirical analysis of women farmers' practices in Latin America. The combination drove to discuss the benefits of peasants' conceptions about food systems and their connections with local realities and the gender issues linked to the food sovereignty conceptualization. Conclusion meets that reality on the field cannot reach food sovereignty's ideal homogeneously and that agricultural sustainable practices are dependent on rights' achievement and social inequalities' eradication.

Keywords: food sovereignty, gender, diversified agricultural systems, access to natural resources

Procedia PDF Downloads 233
8418 Comparative Evaluation of Vanishing Interfacial Tension Approach for Minimum Miscibility Pressure Determination

Authors: Waqar Ahmad Butt, Gholamreza Vakili Nezhaad, Ali Soud Al Bemani, Yahya Al Wahaibi

Abstract:

Minimum miscibility pressure (MMP) plays a great role in determining the displacement efficiency of different gas injection processes. Experimental techniques for MMP determination include industrially recommended slim tube, vanishing interfacial tension (VIT) and rising bubble apparatus (RBA). In this paper, MMP measurement study using slim tube and VIT experimental techniques for two different crude oil samples (M and N) both in live and stock tank oil forms is being presented. VIT measured MMP values for both 'M' and 'N' live crude oils were close to slim tube determined MMP values with 6.4 and 5 % deviation respectively. Whereas for both oil samples in stock tank oil form, VIT measured MMP showed a higher unacceptable deviation from slim tube determined MMP. This higher difference appears to be related to high stabilized crude oil heavier fraction and lack of multiple contacts miscibility. None of the different nine deployed crude oil and CO2 MMP computing correlations could result in reliable MMP, close to slim tube determined MMP. Since VIT determined MMP values for both considered live crude oils are in close match with slim tube determined MMP values, it confirms reliable, reproducible, rapid and cheap alternative for live crude oil MMP determination. Whereas VIT MMP determination for stock tank oil case needed further investigation about stabilization / destabilization mechanism of oil heavier ends and multiple contacts miscibility development issues.

Keywords: minimum miscibility pressure, interfacial tension, multiple contacts miscibility, heavier ends

Procedia PDF Downloads 258
8417 Tick Infestation and its Implications on Health and Welfare of Cattle under Pastoral System in Nigeria

Authors: Alabi Olufemi, Adeyanju Taiwo, Oloruntoba Oluwasegun, Adeleye Bobola, Alabi Oyekemi

Abstract:

The pastoral system is a predominant form of cattle production in Nigeria, characterized by extensive grazing on communal lands. However, this system is challenged by various factors, including tick infestation, which significantly affects cattle health and welfare hence this investigation which aims to provide an in-depth understanding of tick infestation in the context of Nigerian pastoral systems, emphasizing its impact on cattle health and welfare. The country harbors a diverse array of tick species that affect cattle. These ticks belong to different genera, including Rhipicephalus, Amblyomma, and Hyalomma, among others. Each species has unique characteristics, life cycles, and host preferences, contributing to the complexity of tick infestation dynamics in pastoral settings. Tick infestation has numerous detrimental effects on cattle health. The direct effects include blood loss, anemia, skin damage due to feeding, and the transmission of pathogens that cause diseases such as anaplasmosis, babesiosis, and theileriosis. Indirectly, tick infestation can lead to reduced productivity, weight loss, and increased susceptibility to other diseases.The welfare of cattle in Nigerian pastoral systems is significantly impacted by tick infestation. Infested cattle often exhibit signs of distress, including restlessness, reduced grazing activity, and altered behavior. Furthermore, the discomfort caused by tick bites can lead to chronic stress, compromising the overall welfare of the animals. Effective tick control is crucial for mitigating the impact of infestation on cattle health and welfare. Strategies such as acaricide application, pasture management, genetic selection for tick resistance cattle, and vaccination against tick-borne diseases are commonly used. Tick infestation presents a significant challenge to cattle production under the pastoral system in Nigeria. It not only impacts cattle health but also compromises their welfare. Addressing the issue of tick infestation requires a multifaceted approach that integrates effective control strategies with sustainable management practices. Further research is needed to develop tailored interventions that account for the unique characteristics of Nigerian pastoral systems, ultimately ensuring the well-being and productivity of cattle in these settings.

Keywords: tick infestation, pastoral system, welfare, cattle

Procedia PDF Downloads 29
8416 Distributed Real-time Framework for Experimental Multi Aerial Robotic Systems

Authors: Samuel Knox, Verdon Crann, Peyman Amiri, William Crowther

Abstract:

There exists a shortage of open-source firmware for allowing researchers to focus on implementing high-level planning and control strategies for multi aerial robotic systems in simulation and experiment. Within this body of work, practical firmware is presented, which performs all supplementary tasks, including communications, pre and post-experiment procedures, and emergency safety measures. This allows researchers to implement high-level planning and control algorithms for path planning, traffic management, flight formation and swarming of aerial robots. The framework is built in Python using the MAVSDK library, which is compatible with flight controllers running PX4 firmware and onboard computers based on Linux. Communication is performed using Wi-Fi and the MQTT protocol, currently implemented using a centralized broker. Finally, a graphical user interface (GUI) has been developed to send general commands and monitor the agents. This framework enables researchers to prepare customized planning and control algorithms in a modular manner. Studies can be performed experimentally and in simulation using PX4 software in the loop (SITL) and the Gazebo simulator. An example experimental use case of the framework is presented using novel distributed planning and control strategies. The demonstration is performed using off-the-shelf components and minimal setup.

Keywords: aerial robotics, distributed framework, experimental, planning and control

Procedia PDF Downloads 101
8415 SEM Detection of Folate Receptor in a Murine Breast Cancer Model Using Secondary Antibody-Conjugated, Gold-Coated Magnetite Nanoparticles

Authors: Yasser A. Ahmed, Juleen M Dickson, Evan S. Krystofiak, Julie A. Oliver

Abstract:

Cancer cells urgently need folate to support their rapid division. Folate receptors (FR) are over-expressed on a wide range of tumor cells, including breast cancer cells. FR are distributed over the entire surface of cancer cells, but are polarized to the apical surface of normal cells. Targeting of cancer cells using specific surface molecules such as folate receptors may be one of the strategies used to kill cancer cells without hurting the neighing normal cells. The aim of the current study was to try a method of SEM detecting FR in a murine breast cancer cell model (4T1 cells) using secondary antibody conjugated to gold or gold-coated magnetite nanoparticles. 4T1 cells were suspended in RPMI medium witth FR antibody and incubated with secondary antibody for fluorescence microscopy. The cells were cultured on 30mm Thermanox coverslips for 18 hours, labeled with FR antibody then incubated with secondary antibody conjugated to gold or gold-coated magnetite nanoparticles and processed to scanning electron microscopy (SEM) analysis. The fluorescence microscopy study showed strong punctate FR expression on 4T1 cell membrane. With SEM, the labeling with gold or gold-coated magnetite conjugates showed a similar pattern. Specific labeling occurred in nanoparticle clusters, which are clearly visualized in backscattered electron images. The 4T1 tumor cell model may be useful for the development of FR-targeted tumor therapy using gold-coated magnetite nano-particles.

Keywords: cancer cell, nanoparticles, cell culture, SEM

Procedia PDF Downloads 722
8414 Evaluation of Firearm Injury Syndromic Surveillance in Utah

Authors: E. Bennion, A. Acharya, S. Barnes, D. Ferrell, S. Luckett-Cole, G. Mower, J. Nelson, Y. Nguyen

Abstract:

Objective: This study aimed to evaluate the validity of a firearm injury query in the Early Notification of Community-based Epidemics syndromic surveillance system. Syndromic surveillance data are used at the Utah Department of Health for early detection of and rapid response to unusually high rates of violence and injury, among other health outcomes. The query of interest was defined by the Centers for Disease Control and Prevention and used chief complaint and discharge diagnosis codes to capture initial emergency department encounters for firearm injury of all intents. Design: Two epidemiologists manually reviewed electronic health records of emergency department visits captured by the query from April-May 2020, compared results, and sent conflicting determinations to two arbiters. Results: Of the 85 unique records captured, 67 were deemed probable, 19 were ruled out, and two were undetermined, resulting in a positive predictive value of 75.3%. Common reasons for false positives included non-initial encounters and misleading keywords. Conclusion: Improving the validity of syndromic surveillance data would better inform outbreak response decisions made by state and local health departments. The firearm injury definition could be refined to exclude non-initial encounters by negating words such as “last month,” “last week,” and “aftercare”; and to exclude non-firearm injury by negating words such as “pellet gun,” “air gun,” “nail gun,” “bullet bike,” and “exit wound” when a firearm is not mentioned.

Keywords: evaluation, health information system, firearm injury, syndromic surveillance

Procedia PDF Downloads 157
8413 Observations of Magnetospheric Ulf Waves in Connection to the Kelvin-Helmholtz Instability at Mercury

Authors: Elisabet Liljeblad, Tomas Karlsson, Torbjorn Sundberg, Anita Kullen

Abstract:

The magnetospheric magnetic field data from the MESSENGER spacecraft is investigated to establish the presence of ultra-low frequency (ULF) waves in connection to 131 previously observed nonlinear Kelvin-Helmholtz waves (KHWs) at Mercury. Distinct ULF signatures are detected in 44 out of the 131 magnetospheric traversals prior to or after observing a KHW. In particular, 39 of these 44 ULF events are highly coherent at the frequency of maximum power spectral density. The waves observed at the dayside, which appears mainly at the duskside and naturally following the KHW occurrence asymmetry, are significantly different to the events behind the dawn-dusk terminator and have the following distinct wave characteristics: they oscillate clearly in the perpendicular (azimuthal) direction to the mean magnetic field with a wave normal angle more in the parallel than the perpendicular direction, increase in absolute ellipticity with distance from noon, are almost exclusively right-hand polarized, and are observed mainly for frequencies in the range 0.02-0.04 Hz. These results indicate that the dayside ULF waves are likely to shear Alfvén waves driven by KHWs at the magnetopause, which in turn manifests the importance of the Kelvin-Helmholtz instability in terms of mass transport throughout the Mercury magnetosphere.

Keywords: ultra-low frequency waves, kelvin-Helmholtz instability, magnetospheric processes, mercury, messenger, energy and momentum transfer in planetary environments

Procedia PDF Downloads 226
8412 Campus Signage and Wayfinding Design Guidelines: Challenges of Visual Literacy in University of Port Harcourt

Authors: Kasi Jockeil-Ojike

Abstract:

The study of signage and wayfinding design guidelines is to provide consistent, coherent, and comprehensive guidelines for all type of signage design that may be applied to guide persons from the freeway into campus, and to specific building. As the world becomes more complex and the population increases, people increasingly rely on signage and wayfinding systems to navigate their way in built environment such as university campus. This paper will demonstrate and discuss signage and wayfinding, and the importance of visual literacy in university campuses. It discusses the process of wayfinding and signage, how poor signage and wayfinding systems affect people when navigating, and why wayfinding is more than just signage. Hence, this paper tries to examine the design guideline that primarily addresses the signage and wayfinding system that improves visual literacy within University of Port Harcourt multi-campuses. In doing this, the paper explore the environmental graphic design senori-emotional values and communicative information theories that takes the subjectivity of the observer in account. By making these connections, the paper will also determine what University of Port Harcourt need to focus on to be counted in the global trends, using developed visual communication guidelines based on previous studies or concept from professional. In conclusion, information about why physical structures (buildings and waypaths) on University of Port Harcourt multiple campuses need to be branded in self-communicative manner using signage and wayfinding design as integral part of its physical planning policy is recommended.

Keywords: campus-signage, movement, visual-literacy, wayfinding-guidelines

Procedia PDF Downloads 427
8411 Energy Storage Modelling for Power System Reliability and Environmental Compliance

Authors: Rajesh Karki, Safal Bhattarai, Saket Adhikari

Abstract:

Reliable and economic operation of power systems are becoming extremely challenging with large scale integration of renewable energy sources due to the intermittency and uncertainty associated with renewable power generation. It is, therefore, important to make a quantitative risk assessment and explore the potential resources to mitigate such risks. Probabilistic models for different energy storage systems (ESS), such as the flywheel energy storage system (FESS) and the compressed air energy storage (CAES) incorporating specific charge/discharge performance and failure characteristics suitable for probabilistic risk assessment in power system operation and planning are presented in this paper. The proposed methodology used in FESS modelling offers flexibility to accommodate different configurations of plant topology. It is perceived that CAES has a high potential for grid-scale application, and a hybrid approach is proposed, which embeds a Monte-Carlo simulation (MCS) method in an analytical technique to develop a suitable reliability model of the CAES. The proposed ESS models are applied to a test system to investigate the economic and reliability benefits of the energy storage technologies in system operation and planning, as well as to assess their contributions in facilitating wind integration during different operating scenarios. A comparative study considering various storage system topologies are also presented. The impacts of failure rates of the critical components of ESS on the expected state of charge (SOC) and the performance of the different types of ESS during operation are illustrated with selected studies on the test system. The paper also applies the proposed models on the test system to investigate the economic and reliability benefits of the different ESS technologies and to evaluate their contributions in facilitating wind integration during different operating scenarios and system configurations. The conclusions drawn from the study results provide valuable information to help policymakers, system planners, and operators in arriving at effective and efficient policies, investment decisions, and operating strategies for planning and operation of power systems with large penetrations of renewable energy sources.

Keywords: flywheel energy storage, compressed air energy storage, power system reliability, renewable energy, system planning, system operation

Procedia PDF Downloads 111
8410 Bioremediation of Sea Food Waste in Solid State Fermentation along with Production of Bioactive Agents

Authors: Rahul Warmoota, Aditya Bhardwaj, Steffy Angural, Monika Rana, Sunena Jassal, Neena Puri, Naveen Gupta

Abstract:

Seafood processing generates large volumes of waste products such as skin, heads, tails, shells, scales, backbones, etc. Pollution due to conventional methods of seafood waste disposal causes negative implications on the environment, aquatic life, and human health. Moreover, these waste products can be used for the production of high-value products which are still untapped due to inappropriate management. Paenibacillus sp. AD is known to act on chitinolytic and proteinaceous waste and was explored for its potential to degrade various types of seafood waste in solid-state fermentation. Effective degradation of seafood waste generated from a variety of sources such as fish scales, crab shells, prawn shells, and a mixture of such wastes was observed. 30 to 40 percent degradation in terms of decrease in the mass was achieved. Along with the degradation, chitinolytic and proteolytic enzymes were produced, which can have various biotechnological applications. Apart from this, value-added products such as chitin oligosaccharides and peptides of various degrees of polymerization were also produced, which can be used for various therapeutic purposes. Results indicated that Paenibacillus sp. AD can be used for the development of a process for the infield degradation of seafood waste.

Keywords: chitin, chitin-oligosaccharides, chitinase, protease, biodegradation, crab shells, prawn shells, fish scales

Procedia PDF Downloads 86
8409 A Survey of Field Programmable Gate Array-Based Convolutional Neural Network Accelerators

Authors: Wei Zhang

Abstract:

With the rapid development of deep learning, neural network and deep learning algorithms play a significant role in various practical applications. Due to the high accuracy and good performance, Convolutional Neural Networks (CNNs) especially have become a research hot spot in the past few years. However, the size of the networks becomes increasingly large scale due to the demands of the practical applications, which poses a significant challenge to construct a high-performance implementation of deep learning neural networks. Meanwhile, many of these application scenarios also have strict requirements on the performance and low-power consumption of hardware devices. Therefore, it is particularly critical to choose a moderate computing platform for hardware acceleration of CNNs. This article aimed to survey the recent advance in Field Programmable Gate Array (FPGA)-based acceleration of CNNs. Various designs and implementations of the accelerator based on FPGA under different devices and network models are overviewed, and the versions of Graphic Processing Units (GPUs), Application Specific Integrated Circuits (ASICs) and Digital Signal Processors (DSPs) are compared to present our own critical analysis and comments. Finally, we give a discussion on different perspectives of these acceleration and optimization methods on FPGA platforms to further explore the opportunities and challenges for future research. More helpfully, we give a prospect for future development of the FPGA-based accelerator.

Keywords: deep learning, field programmable gate array, FPGA, hardware accelerator, convolutional neural networks, CNN

Procedia PDF Downloads 108
8408 Underdiagnosis of Supraclavicular Brachial Plexus Metastasis in the Shadow of Cervical Disc Herniation: Insights from a Lung Cancer Case Study

Authors: Eunhwa Jun

Abstract:

This case report describes the misdiagnosis of a patient who presented with right arm pain as cervical disc herniation. The patient had several underlying conditions, including hypertension, diabetes mellitus, liver cirrhosis, a history of lung cancer with left lower lobe lobectomy, and adjuvant chemoradiotherapy. An external cervical spine MRI revealed central protruding discs at the C4-5-6-7 levels. Despite treatment with medication and epidural blocks, the patient's pain persisted. A C-RACZ procedure was planned, but the patient's pain had worsened before admission. Using ultrasound, a brachial plexus block was attempted, but the brachial plexus eluded clear visualization, hinting at underlying neurological complexities. Chest CT revealed a new, large soft tissue mass in the right supraclavicular region with adjacent right axillary lymphadenopathy, leading to the diagnosis of metastatic squamous cell carcinoma. Palliative radiation therapy and chemotherapy were initiated as part of the treatment plan, and the patient's pain score decreased to 3 out of 10 on the Numeric Rating Scale (NRS), revealing the pain was due to metastatic lung cancer.

Keywords: supraclavicula brachial plexus metastasis, cervical disc herniation, brachial plexus block, metastatic lung cancer

Procedia PDF Downloads 29
8407 Analyzing Migration Patterns Using Public Disorder Event Data

Authors: Marie E. Docken

Abstract:

At some point in the lifecycle of a country, patterns of political and social unrest of varying degrees are observed. Events involving public disorder or civil disobedience may produce effects that range a wide spectrum of varying outcomes, depending on the level of unrest. Many previous studies, primarily theoretical in nature, have attempted to measure public disorder in answering why or how it occurs in society by examining causal factors or underlying issues in the social or political position of a population. The main objective in doing so is to understand how these activities evolve or seek some predictive capability for the events. In contrast, this research involves the fusion of analytics and social studies to provide more knowledge of the public disorder and civil disobedience intensity in populations. With a greater understanding of the magnitude of these events, it is believed that we may learn how they relate to extreme actions such as mass migration or violence. Upon establishing a model for measuring civil unrest based upon empirical data, a case study on various Latin American countries is performed. Interpretations of historical events are combined with analytical results to provide insights regarding the magnitude and effect of social and political activism.

Keywords: public disorder, civil disobedience, Latin America, metrics, data analysis

Procedia PDF Downloads 133
8406 Classification of Traffic Complex Acoustic Space

Authors: Bin Wang, Jian Kang

Abstract:

After years of development, the study of soundscape has been refined to the types of urban space and building. Traffic complex takes traffic function as the core, with obvious design features of architectural space combination and traffic streamline. The acoustic environment is strongly characterized by function, space, material, user and other factors. Traffic complex integrates various functions of business, accommodation, entertainment and so on. It has various forms, complex and varied experiences, and its acoustic environment is turned rich and interesting with distribution and coordination of various functions, division and unification of the mass, separation and organization of different space and the cross and the integration of multiple traffic flow. In this study, it made field recordings of each space of various traffic complex, and extracted and analyzed different acoustic elements, including changes in sound pressure, frequency distribution, steady sound source, sound source information and other aspects, to make cluster analysis of each independent traffic complex buildings. It divided complicated traffic complex building space into several typical sound space from acoustic environment perspective, mainly including stable sound space, high-pressure sound space, rhythm sound space and upheaval sound space. This classification can further deepen the study of subjective evaluation and control of the acoustic environment of traffic complex.

Keywords: soundscape, traffic complex, cluster analysis, classification

Procedia PDF Downloads 239
8405 Metastatic Ovarian Tumor Discovered Accidentally during Cesarean Section in a 34 Year Old Woman: A Case Report

Authors: Ghada E. Esheba, Ghufran Kheshaifaty, Kholoud Al-Harbi, Wafa'a Al-Harbi, Ala'a Al-Orabi, Moayad Turkistani

Abstract:

Krukenberg tumor is a rare metastatic ovarian carcinoma that usually occurs in female between 30 - 40 year old and rarely seen after menopause. Stomach is the most common primary site. Histopathological features of krukenberg tumors appear as diffuse stromal proliferation, mucus-production, and numerous signet-cells and these tumors spread mostly by lymphatic route. Treatment and prognostic factors are not well established. This study describes a 34 year old female with a unilateral ovarian mass discovered accidentally during cesarean section delivery and it was misdiagnosed as luteoma of pregnancy, but histopathological examination showed a diffuse infiltration of the ovary and omentum by signet ring cells. These findings were not correlated with luteoma of pregnancy or any other types of primary ovarian tumors like surface epithelial tumor, sex cord stromal tumor or germ cell tumor. However, after the analysis of immunohistochemical results (negative CK7, positive CK20 and CDX-2), the finding was the diagnostic of metastatic krukenberg tumor. Two weeks later, the patient was evaluated and a large gastric tumor was found in her stomach and she underwent gastrectomy.

Keywords: CK7, CK20, CDX-2, Krukenburg tumor, metastatic ovarian tumor

Procedia PDF Downloads 302
8404 Hidro-IA: An Artificial Intelligent Tool Applied to Optimize the Operation Planning of Hydrothermal Systems with Historical Streamflow

Authors: Thiago Ribeiro de Alencar, Jacyro Gramulia Junior, Patricia Teixeira Leite

Abstract:

The area of the electricity sector that deals with energy needs by the hydroelectric in a coordinated manner is called Operation Planning of Hydrothermal Power Systems (OPHPS). The purpose of this is to find a political operative to provide electrical power to the system in a given period, with reliability and minimal cost. Therefore, it is necessary to determine an optimal schedule of generation for each hydroelectric, each range, so that the system meets the demand reliably, avoiding rationing in years of severe drought, and that minimizes the expected cost of operation during the planning, defining an appropriate strategy for thermal complementation. Several optimization algorithms specifically applied to this problem have been developed and are used. Although providing solutions to various problems encountered, these algorithms have some weaknesses, difficulties in convergence, simplification of the original formulation of the problem, or owing to the complexity of the objective function. An alternative to these challenges is the development of techniques for simulation optimization and more sophisticated and reliable, it can assist the planning of the operation. Thus, this paper presents the development of a computational tool, namely Hydro-IA for solving optimization problem identified and to provide the User an easy handling. Adopted as intelligent optimization technique is Genetic Algorithm (GA) and programming language is Java. First made the modeling of the chromosomes, then implemented the function assessment of the problem and the operators involved, and finally the drafting of the graphical interfaces for access to the User. The results with the Genetic Algorithms were compared with the optimization technique nonlinear programming (NLP). Tests were conducted with seven hydroelectric plants interconnected hydraulically with historical stream flow from 1953 to 1955. The results of comparison between the GA and NLP techniques shows that the cost of operating the GA becomes increasingly smaller than the NLP when the number of hydroelectric plants interconnected increases. The program has managed to relate a coherent performance in problem resolution without the need for simplification of the calculations together with the ease of manipulating the parameters of simulation and visualization of output results.

Keywords: energy, optimization, hydrothermal power systems, artificial intelligence and genetic algorithms

Procedia PDF Downloads 408
8403 The Distribution of Prevalent Supplemental Nutrition Assistance Program-Authorized Food Store Formats Differ by U.S. Region and Rurality: Implications for Food Access and Obesity Linkages

Authors: Bailey Houghtaling, Elena Serrano, Vivica Kraak, Samantha Harden, George Davis, Sarah Misyak

Abstract:

United States (U.S.) Department of Agriculture Supplemental Nutrition Assistance Program (SNAP) participants are low-income Americans receiving federal dollars for supplemental food and beverage purchases. Participants use a variety of (traditional/non-traditional) SNAP-authorized stores for household dietary purchases - also representing food access points for all Americans. Importantly consumers' food and beverage purchases from non-traditional store formats tend to be higher in saturated fats, added sugars, and sodium when compared to purchases from traditional (e.g., grocery/supermarket) formats. Overconsumption of energy-dense and low-nutrient food and beverage products contribute to high obesity rates and adverse health outcomes that differ in severity among urban/rural U.S. locations and high/low-income populations. Little is known about the SNAP-authorized food store format landscape nationally, regionally, or by urban-rural status, as traditional formats are currently used as the gold standard in food access research. This research utilized publicly available U.S. databases to fill this large literature gap and to provide insight into modes of food access for vulnerable U.S. populations: (1) SNAP Retailer Locator which provides a list of all authorized food stores in the U.S., and; (2) Rural-Urban Continuum Codes (RUCC) that categorize U.S. counties as urban (RUCC 1-3) or rural (RUCC 4-9). Frequencies were determined for the highest occurring food store formats nationally and within two regionally diverse U.S. states – Virginia in the east and California in the west. Store format codes were assigned (e.g., grocery, drug, convenience, mass merchandiser, supercenter, dollar, club, or other). RUCC was applied to investigate state-level differences in urbanity-rurality regarding prevalent food store formats and Chi Square test of independence was used to determine if food store format distributions significantly (p < 0.05) differed by region or rurality. The resulting research sample that represented highly prevalent SNAP-authorized food stores nationally included 41.25% of all SNAP stores in the U.S. (N=257,839), comprised primarily of convenience formats (31.94%) followed by dollar (25.58%), drug (19.24%), traditional (10.87%), supercenter (6.85%), mass merchandiser (1.62%), non-food store or restaurant (1.81%), and club formats (1.09%). Results also indicated that the distribution of prevalent SNAP-authorized formats significantly differed by state. California had a lower proportion of traditional (9.96%) and a higher proportion of drug (28.92%) formats than Virginia- 11.55% and 19.97%, respectively (p < 0.001). Virginia also had a higher proportion of dollar formats (26.11%) when compared to California (10.64%) (p < 0.001). Significant differences were also observed for rurality variables (p < 0.001). Prominently, rural Virginia had a significantly higher proportion of dollar formats (41.71%) when compared to urban Virginia (21.78%) and rural California (21.21%). Non-traditional SNAP-authorized formats are highly prevalent and significantly differ in distribution by U.S. region and rurality. The largest proportional difference was observed for dollar formats where the least nutritious consumer purchases are documented in the literature. Researchers/practitioners should investigate non-traditional food stores at the local level using these research findings and similar applied methodologies to determine how access to various store formats impact obesity prevalence. For example, dollar stores may be prime targets for interventions to enhance nutritious consumer purchases in rural Virginia while targeting drug formats in California may be more appropriate.

Keywords: food access, food store format, nutrition interventions, SNAP consumers

Procedia PDF Downloads 129
8402 Energy Efficient Plant Design Approaches: Case Study of the Sample Building of the Energy Efficiency Training Facilities

Authors: Idil Kanter Otcu

Abstract:

Nowadays, due to the growing problems of energy supply and the drastic reduction of natural non-renewable resources, the development of new applications in the energy sector and steps towards greater efficiency in energy consumption are required. Since buildings account for a large share of energy consumption, increasing the structural density of buildings causes an increase in energy consumption. This increase in energy consumption means that energy efficiency approaches to building design and the integration of new systems using emerging technologies become necessary in order to curb this consumption. As new systems for productive usage of generated energy are developed, buildings that require less energy to operate, with rational use of resources, need to be developed. One solution for reducing the energy requirements of buildings is through landscape planning, design and application. Requirements such as heating, cooling and lighting can be met with lower energy consumption through planting design, which can help to achieve more efficient and rational use of resources. Within this context, rather than a planting design which considers only the ecological and aesthetic features of plants, these considerations should also extend to spatial organization whereby the relationship between the site and open spaces in the context of climatic elements and planting designs are taken into account. In this way, the planting design can serve an additional purpose. In this study, a landscape design which takes into consideration location, local climate morphology and solar angle will be illustrated on a sample building project.

Keywords: energy efficiency, landscape design, plant design, xeriscape landscape

Procedia PDF Downloads 247
8401 Integrating the Modbus SCADA Communication Protocol with Elliptic Curve Cryptography

Authors: Despoina Chochtoula, Aristidis Ilias, Yannis Stamatiou

Abstract:

Modbus is a protocol that enables the communication among devices which are connected to the same network. This protocol is, often, deployed in connecting sensor and monitoring units to central supervisory servers in Supervisory Control and Data Acquisition, or SCADA, systems. These systems monitor critical infrastructures, such as factories, power generation stations, nuclear power reactors etc. in order to detect malfunctions and ignite alerts and corrective actions. However, due to their criticality, SCADA systems are vulnerable to attacks that range from simple eavesdropping on operation parameters, exchanged messages, and valuable infrastructure information to malicious modification of vital infrastructure data towards infliction of damage. Thus, the SCADA research community has been active over strengthening SCADA systems with suitable data protection mechanisms based, to a large extend, on cryptographic methods for data encryption, device authentication, and message integrity protection. However, due to the limited computation power of many SCADA sensor and embedded devices, the usual public key cryptographic methods are not appropriate due to their high computational requirements. As an alternative, Elliptic Curve Cryptography has been proposed, which requires smaller key sizes and, thus, less demanding cryptographic operations. Until now, however, no such implementation has been proposed in the SCADA literature, to the best of our knowledge. In order to fill this gap, our methodology was focused on integrating Modbus, a frequently used SCADA communication protocol, with Elliptic Curve based cryptography and develop a server/client application to demonstrate the proof of concept. For the implementation we deployed two C language libraries, which were suitably modify in order to be successfully integrated: libmodbus (https://github.com/stephane/libmodbus) and ecc-lib https://www.ceid.upatras.gr/webpages/faculty/zaro/software/ecc-lib/). The first library provides a C implementation of the Modbus/TCP protocol while the second one offers the functionality to develop cryptographic protocols based on Elliptic Curve Cryptography. These two libraries were combined, after suitable modifications and enhancements, in order to give a modified version of the Modbus/TCP protocol focusing on the security of the data exchanged among the devices and the supervisory servers. The mechanisms we implemented include key generation, key exchange/sharing, message authentication, data integrity check, and encryption/decryption of data. The key generation and key exchange protocols were implemented with the use of Elliptic Curve Cryptography primitives. The keys established by each device are saved in their local memory and are retained during the whole communication session and are used in encrypting and decrypting exchanged messages as well as certifying entities and the integrity of the messages. Finally, the modified library was compiled for the Android environment in order to run the server application as an Android app. The client program runs on a regular computer. The communication between these two entities is an example of the successful establishment of an Elliptic Curve Cryptography based, secure Modbus wireless communication session between a portable device acting as a supervisor station and a monitoring computer. Our first performance measurements are, also, very promising and demonstrate the feasibility of embedding Elliptic Curve Cryptography into SCADA systems, filling in a gap in the relevant scientific literature.

Keywords: elliptic curve cryptography, ICT security, modbus protocol, SCADA, TCP/IP protocol

Procedia PDF Downloads 245
8400 Effectiveness of Public Speaking Extracurricular in Gontor in Raising Leaders of the Advanced Global World's Needs

Authors: Ummi Sholihah Pertiwi Abidin, Khusnul Hajar Nuansari

Abstract:

Human resource is one of the most important components that can not be separated from communication fields, either in a large community like a mass or narrow ones such as an institution, office, group and even family. Human resource is an asset which is often used as a tool to achieve certain goals. Therefore, development of human resources is essential for improving skills and character of a person especially at the time that has entered globalization era. People are required to be able to compete both in the local and international arena, no matter what. This paper raised topic related to human resource development solution by a unique educational leadership and communication skill improvement through a linguistic approach. Here the authors want to go by form of public speaking method applied in Modern Islamic Boarding School Darussalam Gontor as the extracurricular activity that is using three languages, they are: Indonesian as the mother language or the nation language of the students, Arabic and English as the second language and Gontor’s mean to supply its students to be able to conquer the globalization needs. This implementation produced the establishment of great leaders through confidence growing to speak in public by adjusting the listener context. In linguistic term, it will help enhancing verbal and nonverbal communication skills and so forth in owning a lot of vocabulary.

Keywords: public speaking, Gontor, language, leadership

Procedia PDF Downloads 240
8399 Seroprevalence and Associated Factors of Hepatitis B and Hepatitis C Viral Infections Among Prisoners in Tigray, Northern Ethiopia

Authors: Belaynesh Tsegay, Teklay Gebrecherkos, Atsebaha Gebrekidan Kahsay, Mahmud Abdulkader

Abstract:

Background: Hepatitis B and C viruses are important health and socioeconomic problem across the globe, with a remarkable number of diseases and deaths in sub-Saharan African countries. The burden of hepatitis is unknown in the prison settings of Tigray. Therefore, we aimed to describe the seroprevalence and associated factors of hepatitis B and C viruses among prisoners in Tigray, Ethiopia. Methods: A cross-sectional study was carried out from February 2020 to May 2020 at the prison facilities of Tigray. Demographics and associated factors were collected from 315 prisoners prospectively. Five milliliters of blood were collected and tested using rapid tests kits of HBsAg (Zhejiang orient Gene Biotech Co., Ltd., China) and HCV antibodies (Volkan Kozmetik Sanayi Ve Ticaret Ltd. STI, Turkey). Positive samples were confirmed using ELISA (Beijing Wantai Biological Pharmacy Enterprise Co. Ltd). Data were analyzed using the SPSS version 20, and p<0.05 was considered statistically significant. Results: The overall seroprevalence of HBV and HCV were 25 (7.9%) and 1 (0.3%), respectively. The majority of hepatitis B viral infections were identified from the age groups of 18–25 years (10.7%) and unmarried prisoners (11.8%). Prisoners greater than 100 per cell (AOR=3.95, 95% CI=1.15–13.6, p=0.029) and with a history of alcohol consumption (AOR=3.01, 95% CI=1.17–7.74, p=0.022) were significantly associated with HBV infections. Conclusion: The seroprevalence of HBV among prisoners was nearly high or borderline, with a very low HCV prevalence. HBV was most prevalent among young adults, those housed with a large number of prisoners per cell, and those who had a history of alcohol consumption. This study recommends that there should be prison-focused intervention, including regular health education, with the emphasis on the mode of transmission and introducing HBV screening policy for prisoners, especially when they enter the prison.

Keywords: seroprevalence, HBV, HCV, prisoners, tigray

Procedia PDF Downloads 66
8398 From Synthesis to Application of Photovoltaic Perovskite Nanowires

Authors: László Forró

Abstract:

The organolead halide perovskite CH3NH3PbI3 and its derivatives are known to be very efficient light harvesters revolutionizing the field of solid-state solar cells. The major research area in this field is photovoltaic device engineering although other applications are being explored, as well. Recently, we have shown that nanowires of this photovoltaic perovskite can be synthesized which in association with carbon nanostructures (carbon nanotubes and graphene) make outstanding composites with rapid and strong photo-response. They can serve as conducting electrodes, or as central components of detectors. The performance of several miniature devices based on these composite structures will be demonstrated. Our latest findings on the guided growth of perovskite nanowires by solvatomorph graphoepitaxy will be presented. This method turned out to be a fairly simple approach to overcome the spatially random surface nucleation. The process allows the synthesis of extremely long (centimeters) and thin (a few nanometers) nanowires with a morphology defined by the shape of nanostructured open fluidic channels. This low-temperature solution-growth method could open up an entirely new spectrum of architectural designs of organometallic-halide-perovskite-based heterojunctions and tandem solar cells, LEDs and other optoelectronic devices. Acknowledgment: This work is done in collaboration with Endre Horvath, Massimo Spina, Alla Arakcheeva, Balint Nafradi, Eric Bonvin1, Andrzej Sienkievicz, Zsolt Szekrenyes, Hajnalka Tohati, Katalin Kamaras, Eduard Tutis, Laszlo Mihaly and Karoly Holczer The research is supported by the ERC Advanced Grant (PICOPROP670918).

Keywords: photovoltaics, perovskite, nanowire, photodetector

Procedia PDF Downloads 340
8397 Label Free Detection of Small Molecules Using Surface-Enhanced Raman Spectroscopy with Gold Nanoparticles Synthesized with Various Capping Agents

Authors: Zahra Khan

Abstract:

Surface-Enhanced Raman Spectroscopy (SERS) has received increased attention in recent years, focusing on biological and medical applications due to its great sensitivity as well as molecular specificity. In the context of biological samples, there are generally two methodologies for SERS based applications: label-free detection and the use of SERS tags. The necessity of tagging can make the process slower and limits the use for real life. Label-free detection offers the advantage that it reports direct spectroscopic evidence associated with the target molecule rather than the label. Reproducible, highly monodisperse gold nanoparticles (Au NPs) were synthesized using a relatively facile seed-mediated growth method. Different capping agents (TRIS, citrate, and CTAB) were used during synthesis, and characterization was performed. They were then mixed with different analyte solutions before drop-casting onto a glass slide prior to Raman measurements to see which NPs displayed the highest SERS activity as well as their stability. A host of different analytes were tested, both non-biomolecules and biomolecules, which were all successfully detected using this method at concentrations as low as 10-3M with salicylic acid reaching a detection limit in the nanomolar range. SERS was also performed on samples with a mixture of analytes present, whereby peaks from both target molecules were distinctly observed. This is a fast and effective rapid way of testing samples and offers potential applications in the biomedical field as a tool for diagnostic and treatment purposes.

Keywords: gold nanoparticles, label free, seed-mediated growth, SERS

Procedia PDF Downloads 111
8396 Ultrasound-Assisted Soil Washing Process for the Removal of Heavy Metals from Clays

Authors: Sophie Herr, Antoine Leybros, Yves Barre, Sergey Nikitenko, Rachel Pflieger

Abstract:

The proportion of soil contaminated by a wide range of pollutants (heavy metals, PCBs, pesticides, etc.) of anthropogenic origin is constantly increasing, and it is becoming urgent to address this issue. Among remediation methods, soil washing is an effective, relatively fast, and widely used process. This study assesses its coupling with ultrasound: indeed, sonication induces the formation of cavitation bubbles in solution that enhance local mass transfer through agitation and particle erosion. The removal of target toxic elements Ni(II) and Zn(II) from vermiculite clay has been studied under 20 kHz ultrasound and silent conditions. Several acids were tested, and HCl was chosen as the solvent. The effects of solid/liquid ratio and particle size were investigated. Metal repartition in the clay has been followed by Tessier's sequential extraction procedure. The results showed that more metal elements bound to the challenging residual phase were desorbed with 20 kHz ultrasound than in silent conditions. This supports the promising application of ultrasound for heavy metal desorption in difficult conditions. Further experiments were performed at high-frequency US (362 kHz), and it was shown that fragmentation of the vermiculite particles is then limited, while positive effects of US in the decontamination are kept.

Keywords: desorption, heavy metals, ultrasound, vermiculite

Procedia PDF Downloads 129
8395 Process Modeling in an Aeronautics Context

Authors: Sophie Lemoussu, Jean-Charles Chaudemar, Robertus A. Vingerhoeds

Abstract:

Many innovative projects exist in the field of aeronautics, each addressing specific areas so to reduce weight, increase autonomy, reduction of CO2, etc. In many cases, such innovative developments are being carried out by very small enterprises (VSE’s) or small and medium sized-enterprises (SME’s). A good example concerns airships that are being studied as a real alternative to passenger and cargo transportation. Today, no international regulations propose a precise and sufficiently detailed framework for the development and certification of airships. The absence of such a regulatory framework requires a very close contact with regulatory instances. However, VSE’s/SME’s do not always have sufficient resources and internal knowledge to handle this complexity and to discuss these issues. This poses an additional challenge for those VSE’s/SME’s, in particular those that have system integration responsibilities and that must provide all the necessary evidence to demonstrate their ability to design, produce, and operate airships with the expected level of safety and reliability. The main objective of this research is to provide a methodological framework enabling VSE’s/SME’s with limited resources to organize the development of airships while taking into account the constraints of safety, cost, time and performance. This paper proposes to provide a contribution to this problematic by proposing a Model-Based Systems Engineering approach. Through a comprehensive process modeling approach applied to the development processes, the regulatory constraints, existing best practices, etc., a good image can be obtained as to the process landscape that may influence the development of airships. To this effect, not only the necessary regulatory information is taken on board, also other international standards and norms on systems engineering and project management are being modeled and taken into account. In a next step, the model can be used for analysis of the specific situation for given developments, derive critical paths for the development, identify eventual conflicting aspects between the norms, standards, and regulatory expectations, or also identify those areas where not enough information is available. Once critical paths are known, optimization approaches can be used and decision support techniques can be applied so to better support VSE’s/SME’s in their innovative developments. This paper reports on the adopted modeling approach, the retained modeling languages, and how they all fit together.

Keywords: aeronautics, certification, process modeling, project management, regulation, SME, systems engineering, VSE

Procedia PDF Downloads 145
8394 Impact of Intelligent Transportation System on Planning, Operation and Safety of Urban Corridor

Authors: Sourabh Jain, S. S. Jain

Abstract:

Intelligent transportation system (ITS) is the application of technologies for developing a user–friendly transportation system to extend the safety and efficiency of urban transportation systems in developing countries. These systems involve vehicles, drivers, passengers, road operators, managers of transport services; all interacting with each other and the surroundings to boost the security and capacity of road systems. The goal of urban corridor management using ITS in road transport is to achieve improvements in mobility, safety, and the productivity of the transportation system within the available facilities through the integrated application of advanced monitoring, communications, computer, display, and control process technologies, both in the vehicle and on the road. Intelligent transportation system is a product of the revolution in information and communications technologies that is the hallmark of the digital age. The basic ITS technology is oriented on three main directions: communications, information, integration. Information acquisition (collection), processing, integration, and sorting are the basic activities of ITS. In the paper, attempts have been made to present the endeavor that was made to interpret and evaluate the performance of the 27.4 Km long study corridor having eight intersections and four flyovers. The corridor consisting of six lanes as well as eight lanes divided road network. Two categories of data have been collected such as traffic data (traffic volume, spot speed, delay) and road characteristics data (no. of lanes, lane width, bus stops, mid-block sections, intersections, flyovers). The instruments used for collecting the data were video camera, stop watch, radar gun, and mobile GPS (GPS tracker lite). From the analysis, the performance interpretations incorporated were the identification of peak and off-peak hours, congestion and level of service (LOS) at midblock sections and delay followed by plotting the speed contours. The paper proposed the urban corridor management strategies based on sensors integrated into both vehicles and on the roads that those have to be efficiently executable, cost-effective, and familiar to road users. It will be useful to reduce congestion, fuel consumption, and pollution so as to provide comfort, safety, and efficiency to the users.

Keywords: ITS strategies, congestion, planning, mobility, safety

Procedia PDF Downloads 167
8393 Effects of Surface Roughness on a Unimorph Piezoelectric Micro-Electro-Mechanical Systems Vibrational Energy Harvester Using Finite Element Method Modeling

Authors: Jean Marriz M. Manzano, Marc D. Rosales, Magdaleno R. Vasquez Jr., Maria Theresa G. De Leon

Abstract:

This paper discusses the effects of surface roughness on a cantilever beam vibrational energy harvester. A silicon sample was fabricated using MEMS fabrication processes. When etching silicon using deep reactive ion etching (DRIE) at large etch depths, rougher surfaces are observed as a result of increased response in process pressure, amount of coil power and increased helium backside cooling readings. To account for the effects of surface roughness on the characteristics of the cantilever beam, finite element method (FEM) modeling was performed using actual roughness data from fabricated samples. It was found that when etching about 550um of silicon, root mean square roughness parameter, Sq, varies by 1 to 3 um (at 100um thick) across a 6-inch wafer. Given this Sq variation, FEM simulations predict an 8 to148 Hz shift in the resonant frequency while having no significant effect on the output power. The significant shift in the resonant frequency implies that careful consideration of surface roughness from fabrication processes must be done when designing energy harvesters.

Keywords: deep reactive ion etching, finite element method, microelectromechanical systems, multiphysics analysis, surface roughness, vibrational energy harvester

Procedia PDF Downloads 108