scholarly journals A Comprehensive Study on LPWANs With a Focus on the Potential of LoRa/LoRaWAN Systems

2021 ◽  
Author(s):  
Christos Milarokostas ◽  
Dimitris Tsolkas ◽  
Nikos Passas ◽  
Lazaros Merakos
Keyword(s):  
Wide Area Networks ◽  
Simulation Studies ◽  
Data Generation ◽  
Cloud Infrastructure ◽  
Main Research ◽  
Server Side ◽  
Digital Twins ◽  
Comprehensive Survey ◽  
Shed Light ◽  
Comprehensive Study

This publication offers a comprehensive survey on the topic of Low-Power Wide Area Networks (LPWANs). We discuss the scope of LPWAN connectivity and present numerous well-established technologies that can offer such a service. From this presentation, LoRa/LoRaWAN systems emerge as one of the dominant solutions, and hence we offer details about end-to-end LoRa/LoRaWAN-enabled networking. As an area being in its infancy, LPWANs in general and LoRa/LoRaWAN in specific undergo extensive research. We shed light in key contributions, whereas we also provide our findings regarding the main research focus and needs. Simulation studies appear to be a popular choice among researchers, whereas real system implementations are constantly emerging thanks to low deployment and operational cost. For the former, we offer a comparative overview of existing simulators, whereas for the latter we discuss key considerations about the server-side part of a deployed system, which is usually supported by cloud infrastructure. Finally, LPWANs are systems that experience intense data generation, and thus we deliver a presentation of data-related operations which take place in such systems. This presentation revealed a major vertical market that is expected to be served by LPWANs: the Industiral IoT; which embodies concepts like Asset Administration Shell and Digital Twins.

scholarly journals A Comprehensive Study on LPWANs With a Focus on the Potential of LoRa/LoRaWAN Systems

2021 ◽  
Author(s):  
Christos Milarokostas ◽  
Dimitris Tsolkas ◽  
Nikos Passas ◽  
Lazaros Merakos
Keyword(s):  
Wide Area Networks ◽  
Simulation Studies ◽  
Data Generation ◽  
Cloud Infrastructure ◽  
Main Research ◽  
Server Side ◽  
Digital Twins ◽  
Comprehensive Survey ◽  
Shed Light ◽  
Comprehensive Study

This publication offers a comprehensive survey on the topic of Low-Power Wide Area Networks (LPWANs). We discuss the scope of LPWAN connectivity and present numerous well-established technologies that can offer such a service. From this presentation, LoRa/LoRaWAN systems emerge as one of the dominant solutions, and hence we offer details about end-to-end LoRa/LoRaWAN-enabled networking. As an area being in its infancy, LPWANs in general and LoRa/LoRaWAN in specific undergo extensive research. We shed light in key contributions, whereas we also provide our findings regarding the main research focus and needs. Simulation studies appear to be a popular choice among researchers, whereas real system implementations are constantly emerging thanks to low deployment and operational cost. For the former, we offer a comparative overview of existing simulators, whereas for the latter we discuss key considerations about the server-side part of a deployed system, which is usually supported by cloud infrastructure. Finally, LPWANs are systems that experience intense data generation, and thus we deliver a presentation of data-related operations which take place in such systems. This presentation revealed a major vertical market that is expected to be served by LPWANs: the Industiral IoT; which embodies concepts like Asset Administration Shell and Digital Twins.

scholarly journals A Trust-based Defence Scheme for Mitigating Blackhole and Selective Forwarding Attacks in the RPL Routing Protocol

2018 ◽  
Vol 6 (1) ◽  
pp. 41-59
Author(s):  
David Airehrour ◽  
Jairo Guttierrez ◽  
Sayan Kumar Ray
Keyword(s):  
Routing Protocol ◽  
Research Work ◽  
Simulation Studies ◽  
Proof Of Concept ◽  
Lossy Networks ◽  
Main Research ◽  
Testing Method ◽  
Selective Forwarding ◽  
Testbed Experiments

The routing protocol for low-power and lossy networks (RPL) has gained prominence as the standard IoT routing protocol. However, it faces like many other routing protocols diverse attacks. Many studies have been proposed to secure the RPL protocol, and simulation studies have been put forward as the main research method, while testbed experiments, though an authentic research and testing method, have been ignored. Although testbed experiments and simulation studies have their strengths and limitations, testbed techniques could be used as a verifiable validation method for simulation studies. This study is a follow up research work to validate our simulation study, which addressed Blackhole attacks in the RPL routing protocol. In addition, Selective Forwarding attacks are also addressed. It implements a testbed while embedding our Trust-based RPL protocol and the standard RPL protocol in a smart environment configuration. Based on the test experiments, we provide a proof-of-concept of the validity of our claim that our Trust-based RPL protocol provides a comprehensive defence (simulation and testbed) against Blackhole and Selective Forwarding attacks.

Benchmarks Comparing for IEEE 802.15.4 with Hidden Terminals

2011 ◽  
Vol 403-408 ◽  
pp. 1950-1955
Author(s):  
Zhen Hua Wu ◽  
Xiao Chuan Huang ◽  
Jian Shu
Keyword(s):  
Wireless Network ◽  
Network Performance ◽  
Ieee 802.15.4 ◽  
Performance Degradation ◽  
Data Generation ◽  
Main Research ◽  
Network Load ◽  
Hidden Terminals ◽  
Hidden Terminal ◽  
Packet Length

Hidden terminal problem (HTP) has been a main research aspect in the field of wireless network performance analyzing and testing since it was formulated in 1970s. This article conducts a relatively comprehensive testing on the performance degradation of IEEE 802.15.4 network, which is beacon enabled, star architecture and using slotted CSMA/CA algorithm, due to HTP. All simulate experiments are conducted in NS-2. The experiment results show that: data generation form has little impact on HTP; packet length has more effect on HTP than the number of packets; HTP is trivial when network load is lower than 10%; acknowledge mechanism enlarges extremely HTP; increasing the value of beacon order (BO) is help for alleviating HTP when BO value is small than 6. These conclusions are useful for understanding the features of HTP in IEEE 802.15.4 networks.

Development and Assessment of a Nearly Autonomous Management and Control System During a Single Loss of Flow Accident

2020 ◽  
Author(s):  
Linyu Lin ◽  
Paridhi Athe ◽  
Pascal Rouxelin ◽  
Nam Dinh ◽  
Jeffrey Lane
Keyword(s):  
Knowledge Base ◽  
Confusion Matrix ◽  
Data Generation ◽  
Digital Twin ◽  
Control Functions ◽  
Digital Twins ◽  
Twin Models ◽  
Autonomous Management ◽  
And Performance ◽  
And Control

Abstract In this work, a Nearly Autonomous Management and Control (NAMAC) system is designed to diagnose the reactor state and provide recommendations to the operator for maintaining the safety and performance of the reactor. A three layer-hierarchical workflow is suggested to guide the design and development of the NAMAC system. The three layers in this workflow corresponds to knowledge base, digital twin developmental layer (for different NAMAC functions), and NAMAC operational layer. Digital twin in NAMAC is described as knowledge acquisition system to support different autonomous control functions. Therefore, based on the knowledge base, a set of digital twin models is trained to determine the plant state, predict behavior of physical components or systems, and rank available control options. The trained digital twin models are assembled according to NAMAC operational workflow to support decision-making process in selecting the optimal control actions during an accident scenario. To demonstrate the capability of the NAMAC system, a case study is designed, where a baseline NAMAC is implemented for operating a simulator of the Experimental Breeder Reactor II (EBR-II) during a single loss of flow accident. Training database for development of digital twin models is obtained by sampling the control parameters in the GOTHIC data generation engine. After the training and testing, the digital twins are assembled into a NAMAC system according to the operational workflow. This NAMAC system is coupled with the GOTHIC plant simulator, and a confusion matrix is generated to illustrate the accuracy and robustness of implemented NAMAC system. It is found that within the training databases, NAMAC can make reasonable recommendations with zero confusion rate. However, when the scenario is beyond the training cases, the confusion rate increases, especially when the scenarios are more severe. Therefore, a discrepancy checker is added to detect unexpected reactor states and alert operators for safety-minded actions.

Reactions to Participating in Trauma and Addiction Research Among Women in a Sober Living Home: A Brief Report

2020 ◽  
pp. 088626052091857
Author(s):  
Katie M. Edwards ◽  
Laura Siller ◽  
Sharon B. Murphy
Keyword(s):  
Posttraumatic Growth ◽  
Research Participation ◽  
Emotional Reactions ◽  
Future Research ◽  
Ptsd Symptoms ◽  
Comprehensive Survey ◽  
Survey Results ◽  
Current Psychological ◽  
Almost All ◽  
Shed Light

The purpose of this study was to examine reactions to participating in trauma and addiction research among women in a sober living home. Participants were 59 women who completed a comprehensive survey battery while living in the sober living home. The survey assessed women’s victimization and addiction history along with current psychological and behavioral health symptoms and resilience characteristics. At the end of the survey, women were asked about their reactions to participating in the survey. Results suggested that whereas 40.7% ( n = 24) of women reported being upset immediately after completing the survey, 96.6% ( n = 56) of women reported that they personally benefited from being in the research study. Women who reported being upset, compared with those who were not upset, had higher levels of depressive and posttraumatic stress disorder (PTSD) symptoms and housing and financial instability and lower levels of empowerment, posttraumatic growth, and sense of purpose. We also asked women to tell us, in their own words, their reasons for being upset (e.g., questions about victimization experiences, loss of children), as well as their reasons for benefiting (e.g., catharsis/venting, learning something new about oneself, the chance to meet the researcher who had nice qualities). In general, the research was well tolerated by most of the participants, and almost all women, including those who were initially upset, reported personal benefits. These data shed light on the factors associated with positive and negative emotional reactions to research participation, which could be important information to include in consent forms in future research with this population.

scholarly journals Hanging by a thread: unusual nocturnal resting behaviour in a jumping spider

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Daniela C. Rößler ◽  
Massimo De Agrò ◽  
Elia Biundo ◽  
Paul S. Shamble
Keyword(s):  
Developmental Stages ◽  
Observation Data ◽  
Adaptive Function ◽  
Jumping Spider ◽  
Visual Sensing ◽  
Resting Behaviour ◽  
Disturbance Response ◽  
Vibration Sensing ◽  
Shed Light ◽  
Comprehensive Study

Abstract Background For diurnal animals that heavily rely on vision, a nocturnal resting strategy that offers protection when vision is compromised, is crucial. We found a population of a common European jumping spider (Evarcha arcuata) that rests at night by suspending themselves from a single silk thread attached overhead to the vegetation, a strategy categorically unlike typical retreat-based resting in this group. Results In a comprehensive study, we collected the first quantitative field and qualitative observation data of this surprising behaviour and provide a detailed description. We tested aspects of site fidelity and disturbance response in the field to assess potential functions of suspended resting. Spiders of both sexes and all developmental stages engage in this nocturnal resting strategy. Interestingly, individual spiders are equally able to build typical silk retreats and thus actively choose between different strategies inviting questions about what factors underlie this behavioural choice. Conclusions Our preliminary data hint at a potential sensory switch from visual sensing during the day to silk-borne vibration sensing at night when vision is compromised. The described behaviour potentially is an effective anti-predator strategy either by acting as an early alarm system via vibration sensing or by bringing the animal out of reach for nocturnal predators. We propose tractable hypotheses to test an adaptive function of suspended resting. Further studies will shed light on the sensory challenges that animals face during resting phases and should target the mechanisms and strategies by which such challenges are overcome.

scholarly journals Survey on Mutation-based Test Data Generation

2015 ◽  
Vol 5 (5) ◽  
pp. 1164
Author(s):  
Hanh Le Thi My ◽  
Binh Nguyen Thanh ◽  
Tung Khuat Thanh
Keyword(s):  
Test Data ◽  
Test Cases ◽  
Generation Process ◽  
Test Data Generation ◽  
Data Generation ◽  
Comprehensive Survey ◽  
Critical Activity ◽  
Automatic Test Data Generation ◽  
Systematic Selection ◽  
Selection Of

<span>The critical activity of testing is the systematic selection of suitable test cases, which be able to reveal highly the faults. Therefore, mutation coverage is an effective criterion for generating test data. Since the test data generation process is very labor intensive, time-consuming and error-prone when done manually, the automation of this process is highly aspired. The researches about automatic test data generation contributed a set of tools, approaches, development and empirical results. In this paper, we will analyse and conduct a comprehensive survey on generating test data based on mutation. The paper also analyses the trends in this field.</span>

scholarly journals Hakîkat Yolcusunun Son Durağı: Nifferî’ye Göre Vakfe / The Final Destination of the Truth Seeker: Waqfah According to Al-Niffarî

2017 ◽  
Vol 6 (2) ◽  
pp. 690
Author(s):  
Mehmet Yıldız
Keyword(s):  
Life Style ◽  
Fourth Century ◽  
Individual Life ◽  
Final Destination ◽  
Islamic Mysticism ◽  
History Of ◽  
Ibn Arabi ◽  
Shed Light ◽  
Comprehensive Study

<p><strong>Abstract</strong></p><p>This study examines Islamic mysticism according to Abdu’l-Jabbar Al-Niffarî who has been accepted as an importing figure in Islamic mysticism and among the pioneers of Ibn Arabi in the history of Sufism. Niffarî, who lived in the fourth century (AH), couldn’t find much fame since he preferred a humble and individual life style. The recent academic researches have shed light on his deserved reputation. The first comprehensive study about Nifferî belongs to M. Mustafa Çakmaklıoğlu in Turkey, which I review in this paper. In this study, Çakmaklıoğlu intensely examines Niffarî’s life, works, and contribution to Sufi knowledge. The author tries to understand Niffarî, who uses a very vehement, dense, symbolic, and paradoxical language, through Ibn Arabi since he is familiar with his earlier works.</p><p><strong>Öz</strong></p><p>Bu çalışma Tasavvuf tarihinde İbn Arabî’nin öncülerinden kabul edilebilecek önemli bir sûfî olan Abdülcebbâr en-Nifferî’yi konu edinmektedir. Hicrî dördüncü asırda yaşayan Nifferî, yapı itibariyle münzevî ve münferit bir hayatı tercih ettiği için kendi döneminden itibaren Tasavvuf tarihinde pek şöhret bulmamıştır. Hak ettiği şöhreti ise yakın geçmişte kendisi üzerinde yapılan bilimsel çalışmalar sonucu elde etmiştir. Türkçe’de Nifferî hakkında yapılan ilk kapsamlı çalışma M. Mustafa ÇAKMAKLIOĞLU’na aittir. Çakmaklıoğlu bu çalışmasında Nifferî’nin hayatını, eserlerini ve Tasavvuf ilmine kazandırdığı <em>vakfe</em>, <em>mevkıf</em> kavramlarını derinlemesine işlemektedir. Yazar çok veciz, yoğun, sembolik, paradoksal bir dil kullanan Nifferî’yi daha önceki çalışmalarında aşina olduğu İbn Arabî üzerinden anlamaya çalışmaktadır. </p>

scholarly journals Enhancing Cloud Computing Security by Using Pixel Key Pattern

2015 ◽  
Vol 14 (7) ◽  
pp. 5919-5928
Author(s):  
Randeep Kaur ◽  
Jagroop Kaur
Keyword(s):  
Data Mining ◽  
Data Centers ◽  
Complete Solution ◽  
Cloud System ◽  
Wide Area Networks ◽  
Cloud Infrastructure ◽  
Cloud Computing Security ◽  
Security Measure ◽  
Private Data ◽  
Access Data

Cloud is a term used as a metaphor for the wide area networks (like internet) or any such large networked environment. It came partly from the cloud-like symbol used to represent the complexities of the networks in the schematic diagrams. It represents all the complexities of the network which may include everything from cables, routers, servers, data centers and all such other devices. Cloud based systems saves data off multiple organizations on shared hardware systems. Data segregation is done by encrypting data of users, but encryption is not complete solution. We can do segregate data by creating virtual partitions of data for saving and allowing user to access data in his partition only. We will be implementing cloud security aspects for data mining by implementing cloud system. After implementing cloud infrastructure for data mining for cloud system we shall be evaluating security measure for data mining in cloud. We will be fixing threats in data mining to Personal/private data in cloud systems.  

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