scholarly journals A GPS Spoofing Generator Using an Open Sourced Vector Tracking-Based Receiver

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3993 ◽  
Author(s):  
Qian Meng ◽  
Li-Ta Hsu ◽  
Bing Xu ◽  
Xiapu Luo ◽  
Ahmed El-Mowafy
Keyword(s):  
Technology Implementation ◽  
Autonomous Vehicles ◽  
Test Results ◽  
Signal Component ◽  
Global Positioning ◽  
Actual Signal ◽  
Vector Tracking ◽  
Commercial Off The Shelf ◽  
Processing Period

Spoofing can seriously threaten the use of the Global Positioning System (GPS) in critical applications such as positioning and navigation of autonomous vehicles. Research into spoofing generation will contribute to assessment of the threat of possible spoofing attacks and help in the development of anti-spoofing methods. However, the recent commercial off-the-shelf (COTS) spoofing generators are expensive and the technology implementation is complicated. To address the above problem and promote the GPS safety-critical applications, a spoofing generator using a vector tracking-based software-defined receiver is proposed in this contribution. The spoofing generator aims to modify the raw signals by cancelling the actual signal component and adding the spoofing signal component. The connections between the spreading code and carrier, and the states of the victim receiver are established through vector tracking. The actual signal can be predicted effectively, and the spoofing signal will be generated with the spoofing trajectory at the same time. The experimental test results show that the spoofing attack signal can effectively mislead the victim receiver to the designed trajectory. Neither the tracking channels nor the positioning observations have abnormal changes during this processing period. The recent anti-spoofing methods cannot detect this internal spoofing easily. The proposed spoofing generator can cover all open-sky satellites with a high quality of concealment. With the superiority of programmability and diversity, it is believed that the proposed method based on an open source software-defined receiver has a great value for anti-spoofing research of different GNSS signals.

scholarly journals Receiver Time Misalignment Correction for GPS-based Attitude Determination

2015 ◽  
Vol 68 (4) ◽  
pp. 646-664 ◽  
Author(s):  
Xiaohong Zhang ◽  
Mingkui Wu ◽  
Wanke Liu
Keyword(s):  
Global Positioning System ◽  
Attitude Determination ◽  
Low Cost ◽  
Baseline Length ◽  
Test Results ◽  
System A ◽  
Global Positioning ◽  
Determination System ◽  
Commercial Off The Shelf ◽  
Baseline Estimation

A prerequisite for a Global Positioning System (GPS) attitude determination is to calculate baselines between antennae with accuracy at the millimetre level simultaneously. However, in order to have a low cost attitude determination system, a set of Commercial-Off-The-Shelf (COTS) receivers with separate clocks are used. In this case, if the receiver clocks are not precisely synchronized, the baseline vector between antennae will be calculated from the GPS signals received at different times. This can be a significant error source for high-kinematic applications. In this paper, two equivalent and effective approaches are developed to compensate this significant bias for baseline estimation and attitude determination. Test results using real airborne GPS data demonstrate that the receiver time misalignment between the two receivers can result in a 5 cm baseline offset for an aircraft with a 50 m/s velocity; the corresponding attitude errors can reach about 0·50° in yaw and 0·10° in pitch respectively for the attitude determination system with a baseline length of 3·79 m. With the proposed methods, these errors can be effectively eliminated.

scholarly journals Road Quality Assessment Using International Roughness Index Method and Accelerometer on Android

2019 ◽  
pp. 62
Author(s):  
Eko Budi Setiawan ◽  
Hadi Nurdin
Keyword(s):  
Visual Observation ◽  
Test Results ◽  
International Roughness Index ◽  
Accelerometer Sensor ◽  
Index Method ◽  
Good Surface ◽  
Quality Detection ◽  
Roughness Index ◽  
Global Positioning

The quality of road conditions can determine comfort in driving. To find out the condition of a road whether it has good surface quality, it can use an accelerometer sensor contained in an android smartphone. This research uses the International Roughness Index (IRI) method combined with the accelerometer sensor and the Global Positioning System (GPS). Application of the results of this study can be used to facilitate the contractor maker and road repair, so they can find out which points need to be repaired. Testing is done using two different vehicles, car and motorcycle. Smartphones with road quality detection applications are attached to the car and motorcycle vehicles using a phone holder. This is to record vibration that occurs while the vehicle is moving based on road conditions. The vibration recording results are then validated in a visual observation to determine the accuracy of the assessment results. Based on the test results the level of accuracy on the car is 90% and the motorcycle is 30%.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

Sinonasal effects of external dacryocystorhinostomy

2021 ◽  
pp. 1-4
Author(s):  
H Eyigor ◽  
E A Cetinkaya ◽  
D T Coban ◽  
G Ozturk ◽  
Ö Erdem
Keyword(s):  
Mucociliary Clearance ◽  
Nasal Symptom ◽  
Ciliary Activity ◽  
Test Results ◽  
Saccharine Test ◽  
Significant Difference ◽  
Symptom Scores ◽  
Endoscopic Score ◽  
External Dacryocystorhinostomy

Abstract Objective External dacryocystorhinostomy is thought to cause mucociliary dysfunction by damaging the mucosa, in turn affecting ciliary activity and mucus quality. This study investigated the effect of external dacryocystorhinostomy on sinonasal function. Methods Patients scheduled for unilateral external dacryocystorhinostomy who underwent endoscopic nasal examination and paranasal sinus computed tomography were included in this study. A saccharine test was performed on the planned surgical side and the mucociliary clearance time was determined. The sinonasal quality of life was measured in all patients, pre-operatively and at six months post-operatively, using the Sino-Nasal Outcome Test-22. The Lund–Kennedy endoscopic score was also determined in all patients, both pre- and post-operatively. Results The study comprised 28 patients (22 females and 6 males). A statistically significant difference was found between the pre- and post-operative saccharine test results (p = 0.006), but not between the pre- and post-operative Sino-Nasal Outcome Test-22 scores (p > 0.05). Conclusion This study is one of only a few to investigate the effect of external dacryocystorhinostomy on sinonasal function. The results showed that external dacryocystorhinostomy impairs mucociliary clearance. The surgical procedure is well tolerated and does not significantly change nasal symptom scores.

An improved nonlinear model considering relative velocity for the friction behavior between untwisted glass-fiber tow and roller

2021 ◽  
pp. 004051752110308
Author(s):  
Yang Liu ◽  
Zhong Xiang ◽  
Xiangqin Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu
Keyword(s):  
Friction Coefficient ◽  
Glass Fiber ◽  
Relative Velocity ◽  
Friction Model ◽  
Woven Fabric ◽  
Test Results ◽  
Application Process ◽  
Friction Behavior ◽  
Improved Model

Friction between the tow and tool surface normally happens during the tow production, fabric weaving, and application process and has an important influence on the quality of the woven fabric. Based on this fact, this paper studied the influence of tension and relative velocity on the three kinds of untwisted-glass-fiber tow-on-roller friction with a Capstan-based test setup. Furthermore, an improved nonlinear friction model taking both tension and velocity into account was proposed. According to statistical test results, firstly, the friction coefficient was found to be positively correlated with tension and relative velocity. Secondly, tension and velocity were complementary on the tow-on-roller friction behavior, with neither being superior to the other. Thirdly, an improved model was found to present well the nonlinear characteristics between friction coefficient and tension and velocity, and predicational results of the model were found to agree well with the observations from Capstan tests.

scholarly journals Do Guidelines for the Diagnosis and Monitoring of Diabetes Mellitus Fulfill the Criteria of Evidence-Based Guideline Development?

2008 ◽  
Vol 54 (11) ◽  
pp. 1872-1882 ◽  
Author(s):  
Eva Nagy ◽  
Joseph Watine ◽  
Peter S Bunting ◽  
Rita Onody ◽  
Wytze P Oosterhuis ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Methodological Quality ◽  
Guideline Development ◽  
Evidence Based ◽  
Test Results ◽  
Time Period ◽  
Therapeutic Guidelines ◽  
Therapeutic Recommendations ◽  
Evidence Based Guideline

Abstract Background: Although the methodological quality of therapeutic guidelines (GLs) has been criticized, little is known regarding the quality of GLs that make diagnostic recommendations. Therefore, we assessed the methodological quality of GLs providing diagnostic recommendations for managing diabetes mellitus (DM) and explored several reasons for differences in quality across these GLs. Methods: After systematic searches of published and electronic resources dated between 1999 and 2007, 26 DM GLs, published in English, were selected and scored for methodological quality using the AGREE Instrument. Subgroup analyses were performed based on the source, scope, length, origin, and date and type of publication of GLs. Using a checklist, we collected laboratory-specific items within GLs thought to be important for interpretation of test results. Results: The 26 diagnostic GLs had significant shortcomings in methodological quality according to the AGREE criteria. GLs from agencies that had clear procedures for GL development, were longer than 50 pages, or were published in electronic databases were of higher quality. Diagnostic GLs contained more preanalytical or analytical information than combined (i.e., diagnostic and therapeutic) recommendations, but the overall quality was not significantly different. The quality of GLs did not show much improvement over the time period investigated. Conclusions: The methodological shortcomings of diagnostic GLs in DM raise questions regarding the validity of recommendations in these documents that may affect their implementation in practice. Our results suggest the need for standardization of GL terminology and for higher-quality, systematically developed recommendations based on explicit guideline development and reporting standards in laboratory medicine.

Properties comparison of GaN epilayers deposited under different growth temperatures

2011 ◽  
Vol 19 (1) ◽  
Author(s):  
P. Wang ◽  
H. Yan ◽  
B. Cao ◽  
W. Wei ◽  
Z. Gan ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Structural Characteristics ◽  
Chemical Vapour ◽  
Optimal Growth ◽  
Good Method ◽  
Test Results ◽  
Temperature Deposition ◽  
Metalorganic Chemical Vapour Deposition ◽  
Gan Film

AbstractUndoped GaN epilayers were grown on c-plane sapphire substrates under different growth temperatures by metalorganic chemical vapour deposition (MOCVD). The optical and structural characteristics of these grown samples were studied and compared. It was found that the crystalline quality of GaN film deposited at 1050°C was better that of other samples. Photoluminescence spectra showed that the intensities of yellow luminescence band of the samples decreased as the growth temperature increased. All above test results demonstrate that high temperature deposition can serve as a good method for high-quality GaN epilayer growth and there exists an optimal growth temperature.

Implementation and Performance Assessment of a Vector Tracking Method Based on a Software GPS Receiver

2011 ◽  
Vol 64 (S1) ◽  
pp. S151-S161 ◽  
Author(s):  
Sihao Zhao ◽  
Mingquan Lu ◽  
Zhenming Feng
Keyword(s):  
Global Positioning System ◽  
Carrier Frequency ◽  
Gps Receiver ◽  
Tracking Loop ◽  
Frequency Tracking ◽  
Tracking Method ◽  
Global Positioning ◽  
Vector Tracking ◽  
Tracking Loops ◽  
And Performance

A number of methods have been developed to enhance the robustness of Global Positioning System (GPS) receivers when there are a limited number of visible satellites. Vector tracking is one of them. It utilizes information from all channels to aid the processing of individual channels to generate receiver positions and velocities. This paper analyzes relationships among code phase, carrier frequency, and receiver position and velocity, and presents a vector loop-tracking algorithm using an Extended Kalman filter implemented in a Matlab-based GPS software receiver. Simulated GPS signals are generated to test the proposed vector tracking method. The results show that when some of the satellites are blocked, the vector tracking loop provides better carrier frequency tracking results for the blocked signals and produces more accurate navigation solutions compared with traditional scalar tracking loops.

Land-uses as Quality of Making Successful Streets in Sulaimaniya City Centre, Iraq

2021 ◽  
Author(s):  
Musaab Al-Obeidy ◽  
Keyword(s):  
Global Positioning System ◽  
Structured Interview ◽  
City Centre ◽  
Key Factors ◽  
City Center ◽  
Qualitative And Quantitative ◽  
Points Of Interest ◽  
Global Positioning ◽  
Questionnaire Surveys

Although, the diverse activities and uses are one of the significant key factors to improve quality of streets, some places and shops in Mawlawi Street are disappeared or used by few number of people, while others are used by high number of people. Moreover, just some attractions and points of interest (POIs) are located in the Global Positioning System (GPS). This issues lead to lake of finding urban diversity in Mawlawi Street. This paper examines and find out the diversity of activities and uses that improves the quality of streets and makes successful streets in Sulaimaniya City Centre. It is also to identify POIs provided in GPS. The study employed a mix-methodology method. 330 questionnaire surveys, 20 semi-structured interview, and qualitative and quantitative observation, were conducted in Mawlawi Street. The results show that the diverse activities and choices are important key to make streets of Sulaimaniya City Center successful. There is also a need to define and insert many places on map for enhancing diversity. To secure the quality of the Street, this study suggests to improve the quality of goods and shops, provide night activities, and refresh some left places and shops along the Street.

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