scholarly journals The Statistics of Computer Clocks and the Design of Synchronization Algorithms

2020 ◽  
Vol 125 ◽  
Author(s):  
Judah Levine
Keyword(s):  
Reference Signal ◽  
Local System ◽  
Time Data ◽  
Time Service ◽  
Remote Server ◽  
Network Time ◽  
Network Time Protocol ◽  
Local Reference ◽  
Message Exchange ◽  
Using Data

In this study, I used standard statistical tools (such as the various forms of the two-sample Allan variance) to characterize the clocks in computers, and I show how the results of this study are used to design algorithms to synchronize the computer clocks. These synchronization algorithms can be used to synchronize the time of a computer to a local reference clock or to a remote server. The algorithms by themselves are not intended to be a simple replacement for software that implements the Network Time Protocol (NTP) or any other similar application. Instead, they describe the statistical principles that should be used to design an algorithm to synchronize any computer clock by using data from any external reference received in any format. These algorithms have been used to synchronize the clocks of the computers that support the Internet Time Service operated by the National Institute of Standards and Technology (NIST), and I illustrate the performance of the algorithm with real-time data from these servers. In addition to presenting the design principles of the algorithm, I illustrate the principles with two specific examples: synchronizing a computer clock to a local reference signal, and the design of a synchronization process that is based on time-difference data received from a remote server over the public Internet. The message exchange between the local system and the remote server in this configuration is realized in NTP format, but that is not a fundamental requirement.

First measurement service applied to event dating for reliable business transactions: metrology for digital transformation using Colombian legal time.

2021 ◽  
Author(s):  
Claudia Fernanda Rodriguez ◽  
Keyword(s):  
Digital Transformation ◽  
National Standards ◽  
National Standard ◽  
National Metrology Institute ◽  
Remote Measurement ◽  
Time Service ◽  
Network Time ◽  
Network Time Protocol ◽  
National Comparison ◽  
The Difference

Diffusing the legal time in Colombia is one missional assessment of INM (National Metrology Institute of Colombia). This is done via a public IP through an NTP server (Network Time Protocol Server) disciplined to the National Standard of Time and Frequency. So, the companies can synchronize their servers, but they do not have certainty about the difference that exists between the time of the client-server and the legal time of the INM server because there is not a constant verification implemented by themselves. In Colombia, the demand for the legal time service has increased because it is used by many companies due to the rise of innovative applications such as time-stamp, digital signature, electronic invoice, and economic transactions. This has an impact on the economic environment of a country for world trade. For this reason, the INM of Colombia implemented a new service to measure the synchronization offset with the legal time, which allows the companies to have a new service that generates reliability respecting the time they use to provide their services. Inspired by the INM contribution to the international comparison Universal Time Coordinated (UTC) and the intercomparison of the National Standards of Time and Frequency implemented through the SIM time scale (SIMT) using GPS (Global Positioning System), the INM developed a customized application for national comparison using NTP. As a result, this is the first remote measurement service as evidence of metrology for digital transformation in Colombia in the field of time and frequency.

scholarly journals Security Vulnerability Assessment of Google Home Connection with an Internet of Things Device

Proceedings ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 1
Author(s):  
Hilal Çepik ◽  
Ömer Aydın ◽  
Gökhan Dalkılıç
Keyword(s):  
Internet Of Things ◽  
Vulnerability Assessment ◽  
Smart Home ◽  
Human Life ◽  
Computer Systems ◽  
Security Vulnerability ◽  
Network Time ◽  
Network Time Protocol ◽  
Home Systems

With virtual assistants, both changes and serious conveniences are provided in human life. For this reason, the use of virtual assistants is increasing. The virtual assistant software has started to be produced as separate devices as well as working on phones, tablets, and computer systems. Google Home is one of these devices. Google Home can work integrated with smart home systems and various Internet of Things devices. The security of these systems is an important issue. As a result of attackers taking over these systems, very serious problems may occur. It is very important to take the necessary actions to detect these problems and to take the necessary measures to prevent possible attacks. The purpose of this study is to test whether an attack that attackers can make to these systems via network time protocol will be successful or not. Accordingly, it has been tried to attack the wireless connection established between Google Home and an Internet of Things device over the network time protocol. Attack results have been shared.

DEVELOPMENT OF AN ALGORITHM FOR FINDING ANOMALIES IN WEATHER REPORTS TO IMPROVE THE QUALITY OF FORECASTS

2021 ◽  
pp. 45-52
Author(s):  
K. G. Yashchenkov ◽  
K. S. Dymko ◽  
N. O. Ukhanov ◽  
A. V. Khnykin
Keyword(s):  
Optimal Method ◽  
Implementation Processes ◽  
Advantages And Disadvantages ◽  
Message Exchange ◽  
Text Information ◽  
Preliminary Preparation ◽  
Using Data ◽  
The Moment

The issues of using data analysis methods to find and correct errors in the reports issued by meteorologists are considered. The features of processing various types of meteorological messages are studied. The advantages and disadvantages of existing methods of classification of text information are considered. The classification methods are compared in order to identify the optimal method that will be used in the developed algorithm for analyzing meteorological messages. The prospects of using each of the methods in the developed algorithm are described. An algorithm for processing the source data is proposed, which consists in using syntactic and logical analysis to preclean the data from various kinds of noise and determine format errors for each type of message. After preliminary preparation the classification method correlates the received set of message characteristics with the previously trained model to determine the error of the current weather report and output the corresponding message to the operator in real time. The software tools used in the algorithm development and implementation processes are described. A complete description of the process of processing a meteorological message is presented from the moment when the message is entered in a text editor until the message is sent to the international weather message exchange service. The developed software is demonstrated, in which the proposed algorithm is implemented, which allows to improve the quality of messages and, as a result, the quality of meteorological forecasts. The results of the implementation of the new algorithm are described by comparing the number of messages containing various types of errors before the implementation of the algorithm and after the implementation.

NTP DRDoS Attack Vulnerability and Mitigation

2014 ◽  
Vol 644-650 ◽  
pp. 2875-2880
Author(s):  
A. Alfraih Abdulaziz Nasser ◽  
Wen Bo Chen
Keyword(s):  
Amplification Factor ◽  
Denial Of Service ◽  
Personal Computers ◽  
Distributed Network ◽  
Network Time ◽  
Hands On ◽  
Time Zones ◽  
Network Time Protocol ◽  
The Way

The Network Time Protocol (NTP) is used to synchronize clocks of various computer devices such as personal computers, tablets, and phones based their set time zones. The network of devices that use these NTP servers form a huge distributed network that attracted a number of attacks from late 2013 towards early 2014. This paper presents a hands-on test of the Distributed Reflection Denial of Service (DRDoS) attack by the monlist command, provides more vulnerability in the protocol, and offers mitigation to these vulnerabilities. A Kali Linux server was used to test the monlist command on its localhost. The results showed that a request with a size of 234 bytes got a response of 4,680 bytes. A busy NTP server can return up to 600 addresses which were theoretically calculated to return approximately 48 kilobytes in 100 packets. Consequently, this results in an amplification factor of 206×. The knowledge of the way the attack can be propagated was an important step in thwarting the attack and mitigating more such threats in the same protocol.

scholarly journals DC Microgrid Utilizing Artificial Intelligence and Phasor Measurement Unit Assisted Inverter

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6086
Author(s):  
Raziq Yaqub ◽  
Mohamed Ali ◽  
Hassan Ali
Keyword(s):  
Artificial Intelligence ◽  
Real Time ◽  
Distribution System ◽  
Reference Signal ◽  
Phasor Measurement Unit ◽  
Measurement Unit ◽  
Time Data ◽  
Dc Microgrid ◽  
Utility Company ◽  
Phasor Measurement

Community microgrids are set to change the landscape of future energy markets. The technology is being deployed in many cities around the globe. However, a wide-scale deployment faces three major issues: initial synchronization of microgrids with the utility grids, slip management during its operation, and mitigation of distortions produced by the inverter. This paper proposes a Phasor Measurement Unit (PMU) Assisted Inverter (PAI) that addresses these three issues in a single solution. The proposed PAI continually receives real-time data from a Phasor Measurement Unit installed in the distribution system of a utility company and keeps constructing a real-time reference signal for the inverter. To validate the concept, a unique intelligent DC microgrid architecture that employs the proposed Phasor Measurement Unit (PMU) Assisted Inverter (PAI) is also presented, alongside the cloud-based Artificial Intelligence (AI), which harnesses energy from community shared resources, such as batteries and the community’s rooftop solar resources. The results show that the proposed system produces quality output and is 98.5% efficient.

scholarly journals Google Traffic sebagai Masukan Kebijakan Transportasi Perkotaan (Studi Kasus: Kota Bandar Lampung)

2020 ◽  
Vol 22 (3) ◽  
pp. 409-417
Author(s):  
Muhammad Zainal Ibad ◽  
Rahayu Sulistyorini ◽  
Chania Rahmah
Keyword(s):  
Urban Areas ◽  
Urban Transportation ◽  
Transportation Policy ◽  
Time Data ◽  
Global Positioning ◽  
Transportation Policies ◽  
Movement System ◽  
Using Data ◽  
The Impact

Congestion in urban areas is vulnerable because of the impact of the growth of activities and an increasingly specialized and complex economy. For this reason, it is necessary to formulate a good urban transportation policy to accommodate increased urban transportation needs. Google Traffic is a feature found on Google Maps to see the level of congestion in an area. Google Traffic can detect an area with red, yellow or green indications through the principle of Real Time Data using data from the Global Positioning System (GPS). This study wanted to see how the use of the Google Traffic Feature as input to urban transportation policies by looking at existing urban transportation policies, analyzing the movement system model on Google Traffic, and analyzing the development of Google Traffic model policies, which would be useful for the development of Urban Transportation Policies, especially Bandar Lampung City as a case study.

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