Search results for: territorial information systems
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 18050

Search results for: territorial information systems

10490 Slice Bispectrogram Analysis-Based Classification of Environmental Sounds Using Convolutional Neural Network

Authors: Katsumi Hirata

Abstract:

Certain systems can function well only if they recognize the sound environment as humans do. In this research, we focus on sound classification by adopting a convolutional neural network and aim to develop a method that automatically classifies various environmental sounds. Although the neural network is a powerful technique, the performance depends on the type of input data. Therefore, we propose an approach via a slice bispectrogram, which is a third-order spectrogram and is a slice version of the amplitude for the short-time bispectrum. This paper explains the slice bispectrogram and discusses the effectiveness of the derived method by evaluating the experimental results using the ESC‑50 sound dataset. As a result, the proposed scheme gives high accuracy and stability. Furthermore, some relationship between the accuracy and non-Gaussianity of sound signals was confirmed.

Keywords: environmental sound, bispectrum, spectrogram, slice bispectrogram, convolutional neural network

Procedia PDF Downloads 111
10489 Competitivity in Procurement Multi-Unit Discrete Clock Auctions: An Experimental Investigation

Authors: Despina Yiakoumi, Agathe Rouaix

Abstract:

Laboratory experiments were run to investigate the impact of different design characteristics of the auctions, which have been implemented to procure capacity in the UK’s reformed electricity markets. The experiment studies competition among bidders in procurement multi-unit discrete descending clock auctions under different feedback policies and pricing rules. Theory indicates that feedback policy in combination with the two common pricing rules; last-accepted bid (LAB) and first-rejected bid (FRB), could affect significantly the auction outcome. Two information feedback policies regarding the bidding prices of the participants are considered; with feedback and without feedback. With feedback, after each round participants are informed of the number of items still in the auction and without feedback, after each round participants have no information about the aggregate supply. Under LAB, winning bidders receive the amount of the highest successful bid and under the FRB the winning bidders receive the lowest unsuccessful bid. Based on the theoretical predictions of the alternative auction designs, it was decided to run three treatments. First treatment considers LAB with feedback; second treatment studies LAB without feedback; third treatment investigates FRB without feedback. Theoretical predictions of the game showed that under FRB, the alternative feedback policies are indifferent to the auction outcome. Preliminary results indicate that LAB with feedback and FRB without feedback achieve on average higher clearing prices in comparison to the LAB treatment without feedback. However, the clearing prices under LAB with feedback and FRB without feedback are on average lower compared to the theoretical predictions. Although under LAB without feedback theory predicts the clearing price will drop to the competitive equilibrium, experimental results indicate that participants could still engage in cooperative behavior and drive up the price of the auction. It is showed, both theoretically and experimentally, that the pricing rules and the feedback policy, affect the bidding competitiveness of the auction by providing opportunities to participants to engage in cooperative behavior and exercise market power. LAB without feedback seems to be less vulnerable to market power opportunities compared to the alternative auction designs. This could be an argument for the use of LAB pricing rule in combination with limited feedback in the UK capacity market in an attempt to improve affordability for consumers.

Keywords: descending clock auctions, experiments, feedback policy, market design, multi-unit auctions, pricing rules, procurement auctions

Procedia PDF Downloads 282
10488 Multi-Criteria Selection and Improvement of Effective Design for Generating Power from Sea Waves

Authors: Khaled M. Khader, Mamdouh I. Elimy, Omayma A. Nada

Abstract:

Sustainable development is the nominal goal of most countries at present. In general, fossil fuels are the development mainstay of most world countries. Regrettably, the fossil fuel consumption rate is very high, and the world is facing the problem of conventional fuels depletion soon. In addition, there are many problems of environmental pollution resulting from the emission of harmful gases and vapors during fuel burning. Thus, clean, renewable energy became the main concern of most countries for filling the gap between available energy resources and their growing needs. There are many renewable energy sources such as wind, solar and wave energy. Energy can be obtained from the motion of sea waves almost all the time. However, power generation from solar or wind energy is highly restricted to sunny periods or the availability of suitable wind speeds. Moreover, energy produced from sea wave motion is one of the cheapest types of clean energy. In addition, renewable energy usage of sea waves guarantees safe environmental conditions. Cheap electricity can be generated from wave energy using different systems such as oscillating bodies' system, pendulum gate system, ocean wave dragon system and oscillating water column device. In this paper, a multi-criteria model has been developed using Analytic Hierarchy Process (AHP) to support the decision of selecting the most effective system for generating power from sea waves. This paper provides a widespread overview of the different design alternatives for sea wave energy converter systems. The considered design alternatives have been evaluated using the developed AHP model. The multi-criteria assessment reveals that the off-shore Oscillating Water Column (OWC) system is the most appropriate system for generating power from sea waves. The OWC system consists of a suitable hollow chamber at the shore which is completely closed except at its base which has an open area for gathering moving sea waves. Sea wave's motion pushes the air up and down passing through a suitable well turbine for generating power. Improving the power generation capability of the OWC system is one of the main objectives of this research. After investigating the effect of some design modifications, it has been concluded that selecting the appropriate settings of some effective design parameters such as the number of layers of Wells turbine fans and the intermediate distance between the fans can result in significant improvements. Moreover, simple dynamic analysis of the Wells turbine is introduced. Furthermore, this paper strives for comparing the theoretical and experimental results of the built experimental prototype.

Keywords: renewable energy, oscillating water column, multi-criteria selection, Wells turbine

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10487 A Comparison of Dietary Quality and Nutritional Adequacy of Meal Plans of a Diet Prescription Generator Web App against the Australian Guidelines to Healthy Eating

Authors: Ananda Perera

Abstract:

Diet therapy has a positive impact on many diseases in General Practice. If a meal plan can be generated as easily as writing a drug prescription for dyspepsia, then the evidence and practice gap in nutrition therapy can be narrowed. Meal plans of 50 diet prescriptions were compared with the criteria for a healthy diet given by Australian authorities. The energy value of each meal plan was compared with the recommended daily energy requirements of the authorities for Diet Prescription Generator (DPG) accuracy. Meal plans generated were within the criteria laid down by the Australian authorities for a healthy diet.

Keywords: dieting, obesity, diabetes, weight loss, computerized decision support systems, dieting software, CDSS, meal plans

Procedia PDF Downloads 124
10486 Application of Artificial Neural Networks to Adaptive Speed Control under ARDUINO

Authors: Javier Fernandez De Canete, Alvaro Fernandez-Quintero

Abstract:

Nowadays, adaptive control schemes are being used when model based control schemes are applied in presence of uncertainty and model mismatches. Artificial neural networks have been employed both in modelling and control of non-linear dynamic systems with unknown dynamics. In fact, these are powerful tools to solve this control problem when only input-output operational data are available. A neural network controller under SIMULINK together with the ARDUINO hardware platform has been used to perform real-time speed control of a computer case fan. Comparison of performance with a PID controller has also been presented in order to show the efficacy of neural control under different command signals tracking and also when disturbance signals are present in the speed control loops.

Keywords: neural networks, ARDUINO platform, SIMULINK, adaptive speed control

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10485 Sustainable Water Resource Management and Challenges in Indian Agriculture

Authors: Rajendra Kumar Isaac, Monisha Isaac

Abstract:

India, having a vast cultivable area and regional climatic variability, encounters water Resource Management Problems at various levels. The agricultural production of India needs to be increased to meet out projected population growth. Sustainable water resource is the only option to ensure food security, especially in northern Indian states, where the ground and surface water resources are fast depleting. Various tools and technologies available for management of scarce water resources have been discussed. It was concluded that multiple use of water, adopting latest water management options, identification of climate adoptable cropping and farming systems, can enhance water productivity and would encounter the fast growing water management and water shortage problems in Indian agriculture.

Keywords: water resource management, sustainable, water management technologies, water productivity, agriculture

Procedia PDF Downloads 386
10484 A Problem with IFOC and a New PWM Based 180 Degree Conduction Mode

Authors: Usman Nasir, Minxiao Han, S. M. R. Kazmi

Abstract:

Three phase inverters being used today are based on field orientation control (FOC) and sine wave PWM (SPWM) techniques because 120 degree or 180 degree conduction methods produce high value of THD (total harmonic distortion) in the power system. The indirect field orientation control (IFOC) method is difficult to implement in real systems due to speed sensor accuracy issue. This paper discusses the problem with IFOC and a PWM based 180 degree conduction mode for the three phase inverter. The modified control method improves THD and this paper also compares the results obtained using modified control method with the conventional 180 degree conduction mode.

Keywords: three phase inverters, IFOC, THD, sine wave PWM (SPWM)

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10483 Evaluating Classification with Efficacy Metrics

Authors: Guofan Shao, Lina Tang, Hao Zhang

Abstract:

The values of image classification accuracy are affected by class size distributions and classification schemes, making it difficult to compare the performance of classification algorithms across different remote sensing data sources and classification systems. Based on the term efficacy from medicine and pharmacology, we have developed the metrics of image classification efficacy at the map and class levels. The novelty of this approach is that a baseline classification is involved in computing image classification efficacies so that the effects of class statistics are reduced. Furthermore, the image classification efficacies are interpretable and comparable, and thus, strengthen the assessment of image data classification methods. We use real-world and hypothetical examples to explain the use of image classification efficacies. The metrics of image classification efficacy meet the critical need to rectify the strategy for the assessment of image classification performance as image classification methods are becoming more diversified.

Keywords: accuracy assessment, efficacy, image classification, machine learning, uncertainty

Procedia PDF Downloads 194
10482 Review of Studies on Agility in Knowledge Management

Authors: Ferdi Sönmez, Başak Buluz

Abstract:

Agility in Knowledge Management (AKM) tries to capture agility requirements and their respective answers within the framework of knowledge and learning for organizations. Since it is rather a new construct, it is difficult to claim that it has been sufficiently discussed and analyzed in practical and theoretical realms. Like the term ‘agile learning’, it is also commonly addressed in the software development and information technology fields and across the related areas where those technologies can be applied. The organizational perspective towards AKM, seems to need some more time to become scholarly mature. Nevertheless, in the literature one can come across some implicit usages of this term occasionally. This research is aimed to explore the conceptual background of agility in KM, re-conceptualize it and extend it to business applications with a special focus on e-business.

Keywords: knowledge management, agility requirements, agility, knowledge

Procedia PDF Downloads 249
10481 Application of Modulo-2 Arithmetic in Securing Communicated Messages throughout the Globe

Authors: Ejd Garba, Okike Benjamin

Abstract:

Today, the word encryption has become very popular even among non-computer professionals. There is no doubt that some works have been carried out in this area, but more works need to be done. Presently, most of the works on encryption is concentrated on the sender of the message without paying any attention to the message recipient. However, it is a good practice if any message sent to someone is received by the particular person whom the message is sent to. This work seeks to ensure that at the receiving end of the message, there is a security to ensure that the recipient computes a key that would enable the encrypted message to be accessed. This key would be in form of password. This would make it possible for a given message to be sent to several people at the same time. When this happens, it is only those people who computes the key correctly that would be given the opportunity to access even the encrypted message, which can in turn be decrypted using the appropriate key.

Keywords: arithmetic, cyber space, modulo-2, information security

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10480 A Comparative Study about the Use of SMS in Formal Writing of the Students in Universities

Authors: Sajjad Hussain

Abstract:

Technology has revolutionized the way of communication around the globe. Its use and users are multiplying with every passing minute. The current study reveals the effect of SMS on the formal writing of the students. Students are the regular users of this service and have become addict to short language. This short language is understandable to a particular community and not to the whole as it does not adhere to the Standard English writing practices. Data has been collected from quiz, assignments text and through questionaries’ which supports this postulate that students are frequently practicing it in their formal writing. Certain corrosive measures needs to be taken to address the issue. Second language learners have been found it practicing to greater extent.

Keywords: information technology, SMS, messaging, communication, social media, internet, language

Procedia PDF Downloads 523
10479 Money Laundering and Governance in Cryptocurrencies: The Double-Edged Sword of Blockchain Technology

Authors: Jiaqi Yan, Yani Shi

Abstract:

With the growing popularity of bitcoin transactions, criminals have exploited the bitcoin like cryptocurrencies, and cybercriminals such as money laundering have thrived. Unlike traditional currencies, the Internet-based virtual currencies can be used anonymously via the blockchain technology underpinning. In this paper, we analyze the double-edged sword features of blockchain technology in the context of money laundering. In particular, the traceability feature of blockchain-based system facilitates a level of governance, while the decentralization feature of blockchain-based system may bring governing difficulties. Based on the analysis, we propose guidelines for policy makers in governing blockchain-based cryptocurrency systems.

Keywords: cryptocurrency, money laundering, blockchain, decentralization, traceability

Procedia PDF Downloads 182
10478 Analysis of Different Classification Techniques Using WEKA for Diabetic Disease

Authors: Usama Ahmed

Abstract:

Data mining is the process of analyze data which are used to predict helpful information. It is the field of research which solve various type of problem. In data mining, classification is an important technique to classify different kind of data. Diabetes is most common disease. This paper implements different classification technique using Waikato Environment for Knowledge Analysis (WEKA) on diabetes dataset and find which algorithm is suitable for working. The best classification algorithm based on diabetic data is Naïve Bayes. The accuracy of Naïve Bayes is 76.31% and take 0.06 seconds to build the model.

Keywords: data mining, classification, diabetes, WEKA

Procedia PDF Downloads 133
10477 Integration of UPQC Based on Fuzzy Controller for Power Quality Enhancement in Distributed Network

Authors: M. Habab, C. Benachaiba, B. Mazari, H. Madi, C. Benoudjafer

Abstract:

The use of Distributed Generation (DG) has been increasing in recent years to fill the gap between energy supply and demand. This paper presents the grid connected wind energy system with UPQC based on fuzzy controller to compensate for voltage and current disturbances. The proposed system can improve power quality at the point of installation on power distribution systems. Simulation results show the capability of the DG-UPQC intelligent system to compensate sags voltage and current harmonics at the Point of Common Coupling (PCC).

Keywords: shunt active filter, series active filter, UPQC, power quality, sags voltage, distributed generation, wind turbine

Procedia PDF Downloads 397
10476 Ethical, Legal and Societal Aspects of Unmanned Aircraft in Defence

Authors: Henning Lahmann, Benjamyn I. Scott, Bart Custers

Abstract:

Suboptimal adoption of AI in defence organisations carries risks for the protection of the freedom, safety, and security of society. Despite the vast opportunities that defence AI-technology presents, there are also a variety of ethical, legal, and societal concerns. To ensure the successful use of AI technology by the military, ethical, legal, and societal aspects (ELSA) need to be considered, and their concerns continuously addressed at all levels. This includes ELSA considerations during the design, manufacturing and maintenance of AI-based systems, as well as its utilisation via appropriate military doctrine and training. This raises the question how defence organisations can remain strategically competitive and at the edge of military innovation, while respecting the values of its citizens. This paper will explain the set-up and share preliminary results of a 4-year research project commissioned by the National Research Council in the Netherlands on the ethical, legal, and societal aspects of AI in defence. The project plans to develop a future-proof, independent, and consultative ecosystem for the responsible use of AI in the defence domain. In order to achieve this, the lab shall devise a context-dependent methodology that focuses on the ‘analysis’, ‘design’ and ‘evaluation’ of ELSA of AI-based applications within the military context, which include inter alia unmanned aircraft. This is bolstered as the Lab also recognises and complements the existing methods in regards to human-machine teaming, explainable algorithms, and value-sensitive design. Such methods will be modified for the military context and applied to pertinent case-studies. These case-studies include, among others, the application of autonomous robots (incl. semi- autonomous) and AI-based methods against cognitive warfare. As the perception of the application of AI in the military context, by both society and defence personnel, is important, the Lab will study how these perceptions evolve and vary in different contexts. Furthermore, the Lab will monitor – as they may influence people’s perception – developments in the global technological, military and societal spheres. Although the emphasis of the research project is on different forms of AI in defence, it focuses on several case studies. One of these case studies is on unmanned aircraft, which will also be the focus of the paper. Hence, ethical, legal, and societal aspects of unmanned aircraft in the defence domain will be discussed in detail, including but not limited to privacy issues. Typical other issues concern security (for people, objects, data or other aircraft), privacy (sensitive data, hindrance, annoyance, data collection, function creep), chilling effects, PlayStation mentality, and PTSD.

Keywords: autonomous weapon systems, unmanned aircraft, human-machine teaming, meaningful human control, value-sensitive design

Procedia PDF Downloads 82
10475 Review on Effective Texture Classification Techniques

Authors: Sujata S. Kulkarni

Abstract:

Effective and efficient texture feature extraction and classification is an important problem in image understanding and recognition. This paper gives a review on effective texture classification method. The objective of the problem of texture representation is to reduce the amount of raw data presented by the image, while preserving the information needed for the task. Texture analysis is important in many applications of computer image analysis for classification include industrial and biomedical surface inspection, for example for defects and disease, ground classification of satellite or aerial imagery and content-based access to image databases.

Keywords: compressed sensing, feature extraction, image classification, texture analysis

Procedia PDF Downloads 415
10474 Set Up Candid Clips Effectiveness

Authors: P. Suparada, D. Eakapotch

Abstract:

The objectives were to analyze the using of new media in the form of set up candid clip that affects the product and presenter, to study the effectiveness of using new media in the form of set up candid clip in order to increase the circulation and audience satisfaction and to use the earned information and knowledge to develop the communication for publicizing and advertising via new media. This research is qualitative research based on questionnaire and in-depth interview from experts. The findings showed the advantages and disadvantages of communication for publicizing and advertising via new media in the form of set up candid clip including with the specific target group for this kind of advertising. It will be useful for fields of publicizing and advertising in the new media forms at the present.

Keywords: candid clip, communication, new media, social network

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10473 Economic Growth and Total Factor Productivity by the Use of Rail Way Transport in the City of Medellín - Colombia in the Period 2012-2016

Authors: Mauricio Molina

Abstract:

The present research project aims to determine whether it is possible to have a statement, allowing you to have an economic model to establish clearly if the population that uses the rail system underground in the city of Medellin with an increase in productivity total factor. The present project aims to concentrate on the surroundings to the system underground for a period of 60 months in the city of Medellin. According to the review bibliographic is can establish that in it most of them cases, the cities that have with systems of transport rail are more productive. And should to its time present is an analysis that may lead to determine if effectively the use of the transport railway improves the productivity of a city and its inhabitants.

Keywords: economic growth, mobility urban, total factor productivity, rail transport

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10472 Human Resource Management: A Study of Human Resource Practices in 'Maharatna' Central Public Sector Enterprises in India

Authors: Shashi Pingolia

Abstract:

The paper discusses best practices developed and followed by 07 'Maharatna' Central Public sector Enterprises in India. The paper begins with brief analyses of the contribution of ‘Maharatna’ companies in the growth story of India Inc. Progressively; it enlists Human Resource practices and approach of these 'Maharatna' companies in the areas such as Recruitment, Pay structure, Employee Benefits and Development, Rewards and Recognition practices, Performance Management Systems, etc. In the later part of the paper, HR factors that led some of these 'Maharatna' companies from average employers to 'Best Place at Work' are discussed in brief.

Keywords: central public sector enterprises in India, Maharatna companies in India, human resource management, best place to work

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10471 Impulsivity Leads to Compromise Effect

Authors: Sana Maidullah, Ankita Sharma

Abstract:

The present study takes naturalistic decision-making approach to examine the role of personality in information processing in consumer decision making. In the technological era, most of the information comes in form of HTML or similar language via the internet; processing of this situation could be ambiguous, laborious and painful. The present study explores the role of impulsivity in creating an extreme effect on consumer decision making. Specifically, the study explores the role of impulsivity in extreme effect, i.e., extremeness avoidance (compromise effect) and extremeness seeking; the role of demographic variables, i.e. age and gender, in the relation between impulsivity and extreme effect. The study was conducted with the help of a questionnaire and two experiments. The experiment was designed in the form of two shopping websites with two product types: Hotel choice and Mobile choice. Both experimental interfaces were created with the Xampp software, the frontend of interfaces was HTML CSS JAVASCRIPT and backend was PHP MySQL. The mobile experiment was designed to measure the extreme effect and hotel experiment was designed to measure extreme effect with alignability of attributes. To observe the possibilities of the combined effect of individual difference and context effects, the manipulation of price, a number of alignable attributes and number of the non-alignable attributes is done. The study was conducted on 100 undergraduate and post-graduate engineering students within the age range of 18-35. The familiarity and level of use of internet and shopping website were assessed and controlled in the analysis. The analysis was done by using a t-test, ANOVA and regression analysis. The results indicated that the impulsivity leads to compromise effect and at the same time it also increases the relationship between alignability of attribute among choices and the compromise effect. The demographic variables were found to play a significant role in the relationship. The subcomponents of impulsivity were significantly influencing compromise effect, but the cognitive impulsivity was significant for women, and motor impulsivity was significant for males only. The impulsivity was significantly positively predicted by age, though there were no significant gender differences in impulsivity. The results clearly indicate the importance of individual factors in decision making. The present study, with precise and direct results, provides a significant suggestion for market analyst and business providers.

Keywords: impulsivity, extreme effect, personality, alignability, consumer decision making

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10470 The Beta-Fisher Snedecor Distribution with Applications to Cancer Remission Data

Authors: K. A. Adepoju, O. I. Shittu, A. U. Chukwu

Abstract:

In this paper, a new four-parameter generalized version of the Fisher Snedecor distribution called Beta- F distribution is introduced. The comprehensive account of the statistical properties of the new distributions was considered. Formal expressions for the cumulative density function, moments, moment generating function and maximum likelihood estimation, as well as its Fisher information, were obtained. The flexibility of this distribution as well as its robustness using cancer remission time data was demonstrated. The new distribution can be used in most applications where the assumption underlying the use of other lifetime distributions is violated.

Keywords: fisher-snedecor distribution, beta-f distribution, outlier, maximum likelihood method

Procedia PDF Downloads 334
10469 Prosodic Realization of Focus in the Public Speeches Delivered by Spanish Learners of English and English Native Speakers

Authors: Raúl Jiménez Vilches

Abstract:

Native (L1) speakers can mark prosodically one part of an utterance and make it more relevant as opposed to the rest of the constituents. Conversely, non-native (L2) speakers encounter problems when it comes to marking prosodically information structure in English. In fact, the L2 speaker’s choice for the prosodic realization of focus is not so clear and often obscures the intended pragmatic meaning and the communicative value in general. This paper reports some of the findings obtained in an L2 prosodic training course for Spanish learners of English within the context of public speaking. More specifically, it analyses the effects of the course experiment in relation to the non-native production of the tonic syllable to mark focus and compares it with the public speeches delivered by native English speakers. The whole experimental training was executed throughout eighteen input sessions (1,440 minutes total time) and all the sessions took place in the classroom. In particular, the first part of the course provided explicit instruction on the recognition and production of the tonic syllable and how the tonic syllable is used to express focus. The non-native and native oral presentations were acoustically analyzed using Praat software for speech analysis (7,356 words in total). The investigation adopted mixed and embedded methodologies. Quantitative information is needed when measuring acoustically the phonetic realization of focus. Qualitative data such as questionnaires, interviews, and observations were also used to interpret the quantitative data. The embedded experiment design was implemented through the analysis of the public speeches before and after the intervention. Results indicate that, even after the L2 prosodic training course, Spanish learners of English still show some major inconsistencies in marking focus effectively. Although there was occasional improvement regarding the choice for location and word classes, Spanish learners were, in general, far from achieving similar results to the ones obtained by the English native speakers in the two types of focus. The prosodic realization of focus seems to be one of the hardest areas of the English prosodic system to be mastered by Spanish learners. A funded research project is in the process of moving the present classroom-based experiment to an online environment (mobile app) and determining whether there is a more effective focus usage through CAPT (Computer-Assisted Pronunciation) tools.

Keywords: focus, prosody, public speaking, Spanish learners of English

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10468 Use Cases Analysis of Free Space Optical Communication System

Authors: Kassem Saab, Fritzen Bart, Yves-Marie Seveque

Abstract:

The deployment of Free Space Optical Communications (FSOC) systems requires the development of robust and reliable Optical Ground Stations (OGS) that can be easily installed and operated. To this end, the Engineering Department of Airbus Defence and Space is actively working on the development of innovative and compact OGS solutions that can be deployed in various environments and provide high-quality connectivity under different atmospheric conditions. This article presents an overview of our recent developments in this field, including an evaluation study of different use cases of the FSOC with respect to different atmospheric conditions. The goal is to provide OGS solutions that are both simple and highly effective, allowing for the deployment of high-speed communication networks in a wide range of scenarios.

Keywords: end to end optical communication, laser propagation, optical ground station, turbulence

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10467 Half Metallic Antiferromagnetic of Doped TiO2 Rutile with Doubles Impurities (Os, Mo) from Ab Initio Calculations

Authors: M. Fakhim Lamrani, M. Ouchri, M. Belaiche, El Kenz, M. Loulidi, A. Benyoussef

Abstract:

Electronic and magnetic calculations based on density functional theory within the generalized gradient approximation for II-VI compound semiconductor TiO2 doped with single impurity Os and Mo; these compounds are a half metallic ferromagnet in their ground state with a total magnetic moment of 2 μB for both systems. Then, TiO2 doped with double impurities Os and Mo have been performed. As result, Ti1-2xOsxMoxO2 with x=0.065 is half-metallic antiferromagnets with 100% spin polarization of the conduction electrons crossing the Fermi level, without showing a net magnetization. Moreover, Ti14OsMoO32 compound is stable energetically than Ti1-xMoxO2 and Ti1-xOsxO2. The antiferromagnetic interaction in Ti1-2xOsxMoxO2 system is attributed to the double exchange mechanism, and the latter could also be the origin of their half metallic.

Keywords: diluted magnetic semiconductor, half-metallic antiferromagnetic, augmented spherical wave method

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10466 Numerical Experiments for the Purpose of Studying Space-Time Evolution of Various Forms of Pulse Signals in the Collisional Cold Plasma

Authors: N. Kh. Gomidze, I. N. Jabnidze, K. A. Makharadze

Abstract:

The influence of inhomogeneities of plasma and statistical characteristics on the propagation of signal is very actual in wireless communication systems. While propagating in the media, the deformation and evaluation of the signal in time and space take place and on the receiver we get a deformed signal. The present article is dedicated to studying the space-time evolution of rectangular, sinusoidal, exponential and bi-exponential impulses via numerical experiment in the collisional, cold plasma. The presented method is not based on the Fourier-presentation of the signal. Analytically, we have received the general image depicting the space-time evolution of the radio impulse amplitude that gives an opportunity to analyze the concrete results in the case of primary impulse.

Keywords: collisional, cold plasma, rectangular pulse signal, impulse envelope

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10465 Identification of Coauthors in Scientific Database

Authors: Thiago M. R Dias, Gray F. Moita

Abstract:

The analysis of scientific collaboration networks has contributed significantly to improving the understanding of how does the process of collaboration between researchers and also to understand how the evolution of scientific production of researchers or research groups occurs. However, the identification of collaborations in large scientific databases is not a trivial task given the high computational cost of the methods commonly used. This paper proposes a method for identifying collaboration in large data base of curriculum researchers. The proposed method has low computational cost with satisfactory results, proving to be an interesting alternative for the modeling and characterization of large scientific collaboration networks.

Keywords: extraction, data integration, information retrieval, scientific collaboration

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10464 Good Advice Is Hard to Come By: A Cross-Cultural Perspective on Opposing Views and Entrepreneurial Passion

Authors: Marcel Hechler

Abstract:

The purpose of this study is to understand the impact of entrepreneurs' receptiveness to opposing views on their entrepreneurial passion. Following a cross-cultural approach, we surveyed 1,228 entrepreneurs in seven developing and emerging countries. Besides a positive relationship between receptiveness to opposing views and harmonious passion for entrepreneurship, we found first evidence for a significant moderating effect of access to information reinforcing the positive main effect.

Keywords: harmonious passion, developing and emerging countries, self-determination theory, receptiveness to opposing views

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10463 Metalorganic Chemical Vapor Deposition Overgrowth on the Bragg Grating for Gallium Nitride Based Distributed Feedback Laser

Authors: Junze Li, M. Li

Abstract:

Laser diodes fabricated from the III-nitride material system are emerging solutions for the next generation telecommunication systems and optical clocks based on Ca at 397nm, Rb at 420.2nm and Yb at 398.9nm combined 556 nm. Most of the applications require single longitudinal optical mode lasers, with very narrow linewidth and compact size, such as communication systems and laser cooling. In this case, the GaN based distributed feedback (DFB) laser diode is one of the most effective candidates with gratings are known to operate with narrow spectra as well as high power and efficiency. Given the wavelength range, the period of the first-order diffraction grating is under 100 nm, and the realization of such gratings is technically difficult due to the narrow line width and the high quality nitride overgrowth based on the Bragg grating. Some groups have reported GaN DFB lasers with high order distributed feedback surface gratings, which avoids the overgrowth. However, generally the strength of coupling is lower than that with Bragg grating embedded into the waveguide within the GaN laser structure by two-step-epitaxy. Therefore, the overgrowth on the grating technology need to be studied and optimized. Here we propose to fabricate the fine step shape structure of first-order grating by the nanoimprint combined inductively coupled plasma (ICP) dry etching, then carry out overgrowth high quality AlGaN film by metalorganic chemical vapor deposition (MOCVD). Then a series of gratings with different period, depths and duty ratios are designed and fabricated to study the influence of grating structure to the nano-heteroepitaxy. Moreover, we observe the nucleation and growth process by step-by-step growth to study the growth mode for nitride overgrowth on grating, under the condition that the grating period is larger than the mental migration length on the surface. The AFM images demonstrate that a smooth surface of AlGaN film is achieved with an average roughness of 0.20 nm over 3 × 3 μm2. The full width at half maximums (FWHMs) of the (002) reflections in the XRD rocking curves are 278 arcsec for the AlGaN film, and the component of the Al within the film is 8% according to the XRD mapping measurement, which is in accordance with design values. By observing the samples with growth time changing from 200s, 400s to 600s, the growth model is summarized as the follow steps: initially, the nucleation is evenly distributed on the grating structure, as the migration length of Al atoms is low; then, AlGaN growth alone with the grating top surface; finally, the AlGaN film formed by lateral growth. This work contributed to carrying out GaN DFB laser by fabricating grating and overgrowth on the nano-grating patterned substrate by wafer scale, moreover, growth dynamics had been analyzed as well.

Keywords: DFB laser, MOCVD, nanoepitaxy, III-niitride

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10462 When Bad News Are Good News: Ambivalent Feelings Towards Firms Adversity

Authors: Jacob Hornik, Matti Rachamim, Ori Grossman

Abstract:

Schadenfreude, a bittersweet phenomenon, is considered atypical and complicated state that might reflect ambivalent types of sentiments -a mixed of both positive and negative reactions towards others misfortunes. This brief note reports a study that examined the association between trait ambivalence, using the Trait Mixed Emotions Scale (TMES), and four different consumer schadenfreude affairs. Results propose that trait ambivalence offers a novel explanation for schadenfreude responses. Showing that trait ambivalence enhances schadenfreude, when consumers encounter misfortune type of information about a disliked or rival marketplace entity.

Keywords: schadenfreude, consumer behavior, mixed emotions, sentiments, ambivalence

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10461 Geomatic Techniques to Filter Vegetation from Point Clouds

Authors: M. Amparo Núñez-Andrés, Felipe Buill, Albert Prades

Abstract:

More and more frequently, geomatics techniques such as terrestrial laser scanning or digital photogrammetry, either terrestrial or from drones, are being used to obtain digital terrain models (DTM) used for the monitoring of geological phenomena that cause natural disasters, such as landslides, rockfalls, debris-flow. One of the main multitemporal analyses developed from these models is the quantification of volume changes in the slopes and hillsides, either caused by erosion, fall, or land movement in the source area or sedimentation in the deposition zone. To carry out this task, it is necessary to filter the point clouds of all those elements that do not belong to the slopes. Among these elements, vegetation stands out as it is the one we find with the greatest presence and its constant change, both seasonal and daily, as it is affected by factors such as wind. One of the best-known indexes to detect vegetation on the image is the NVDI (Normalized Difference Vegetation Index), which is obtained from the combination of the infrared and red channels. Therefore it is necessary to have a multispectral camera. These cameras are generally of lower resolution than conventional RGB cameras, while their cost is much higher. Therefore we have to look for alternative indices based on RGB. In this communication, we present the results obtained in Georisk project (PID2019‐103974RB‐I00/MCIN/AEI/10.13039/501100011033) by using the GLI (Green Leaf Index) and ExG (Excessive Greenness), as well as the change to the Hue-Saturation-Value (HSV) color space being the H coordinate the one that gives us the most information for vegetation filtering. These filters are applied both to the images, creating binary masks to be used when applying the SfM algorithms, and to the point cloud obtained directly by the photogrammetric process without any previous filter or the one obtained by TLS (Terrestrial Laser Scanning). In this last case, we have also tried to work with a Riegl VZ400i sensor that allows the reception, as in the aerial LiDAR, of several returns of the signal. Information to be used for the classification on the point cloud. After applying all the techniques in different locations, the results show that the color-based filters allow correct filtering in those areas where the presence of shadows is not excessive and there is a contrast between the color of the slope lithology and the vegetation. As we have advanced in the case of using the HSV color space, it is the H coordinate that responds best for this filtering. Finally, the use of the various returns of the TLS signal allows filtering with some limitations.

Keywords: RGB index, TLS, photogrammetry, multispectral camera, point cloud

Procedia PDF Downloads 127