Preliminary Analysis and Evaluation of BDS-3 RDSS Timing Performance

Radio determination satellite service (RDSS) is one of the characteristic services of Beidou navigation satellite system (BDS), and also distinguishes with other GNSS systems. BDS-3 RDSS adopts new signals, which is compatible with BDS-2 RDSS signals in order to guarantee the services of old users. Moreover, the new signals also separate civil signals and military signals which are modulated on different carriers to improve their isolation and RDSS service performance. Timing is an important part of RDSS service, which has been widely used in the field of the power, transportation, marine and others. Therefore, the timing accuracy, availability and continuity is an important guarantee for RDSS service. This paper summarizes the principle of one-way and two-way timing, and provides the evaluation method of RDSS timing accuracy, availability and continuity. Based on BDS-3 RDSS signal measurements of system, the performance of one-way timing and two-way timing is analyzed and evaluated for the first time. The results show that: (1) the accuracy of one-way timing and two-way timing is better than 30 ns and 8 ns respectively, which are better than the official claimed accuracy; (2) the RMS of one-way timing accuracy is 5.45 ns, which is 20% smaller than BDS-2, and the availability and continuity are 100%; (3) the RMS of two-way timing accuracy is 3.59 ns, which is 34% smaller than one-way timing, and both of the availability and continuity are 100%; (4) the orbit maneuver of GEO satellite make the one-way timing has 7.68 h recovery, but has no affection on the two-way timing.

Privacy-Preserving Federated Learning Using Homomorphic Encryption

Federated learning (FL) is a machine learning technique that enables distributed devices to train a learning model collaboratively without sharing their local data. FL-based systems can achieve much stronger privacy preservation since the distributed devices deliver only local model parameters trained with local data to a centralized server. However, there exists a possibility that a centralized server or attackers infer/extract sensitive private information using the structure and parameters of local learning models. We propose employing homomorphic encryption (HE) scheme that can directly perform arithmetic operations on ciphertexts without decryption to protect the model parameters. Using the HE scheme, the proposed privacy-preserving federated learning (PPFL) algorithm enables the centralized server to aggregate encrypted local model parameters without decryption. Furthermore, the proposed algorithm allows each node to use a different HE private key in the same FL-based system using a distributed cryptosystem. The performance analysis and evaluation of the proposed PPFL algorithm are conducted in various cloud computing-based FL service scenarios.

ANALYSIS AND EVALUATION OF ADVANTAGES FROM LAPAROSCOPIC APPENDECTOMY

Purpose: The aim of the study is to evaluate the advantages of laparoscopic appendectomy fromour clinical experience in UMHATEM "Pirogov" which resulted in reduced postoperative complications, pain, length of hospital stay, and early return to work. Material and Methods: Data from a study of a patient group in the Department of General, Visceral and Emergency Surgery of UMBALSM "H. I. Pirogov "for the six-month period (01.01.2019 до 01.07.2019) were collected.Eighty-one patients with acute appendicitis who underwent laparoscopic appendectomy were selected. Indicators characterizing basic clinical and pathological features (epidemiology, demography, degree of pathological impairment), surgical approach and its outcomes (postoperative complications, postoperative duration), influence of concomitant factors were studied. Results: The study included 81 patients. The majority of patients were women - 46 (56.79%), men- 35 (43.21%). The mean age of male patients was 31.4 years and for female-28.6 years respectively. Hospitalization times are usually short - most patients are given up to 72 hours (70- 86.42%). Only eleven patients (13.58%) had an extended hospital stay for observation and additional therapy. Conclusion: Laparoscopic appendectomy was verified as an optimal and safe surgical procedure. Laparoscopic approach reduces post-operative pain, shortens hospital stay, reduces complications, and thereby reducing treatment costs.

A Lightweight Authentication Scheme Based on Consortium Blockchain for Cross-Domain IoT

Internet of Things (IoT) has been ubiquitous in both industrial and living areas, but also known for its weak security. Being as the first defense line against various cyberattacks, authentication is even more critical to IoT applications. Moreover, there has been a growing demand for cross-domain collaboration, leading to an increasing need for cross-domain authentication. Recently, certificate-based authentication schemes have been extensively studied. However, many of these schemes are not efficient in computation, storage, and communication, which are highly required in IoT. In this paper, we propose a lightweight authentication scheme based on consortium blockchain and design a cryptocurrency-like digital token to build trust. Furthermore, trust lifecycle management is performed by manipulating the amount of tokens. The comprehensive analysis and evaluation demonstrate that the proposed scheme is resistant to various common attacks and more efficient than competitor schemes in terms of storage, communication, and authentication cost.

Strategic Digital Informing and Its Challenges in the 21st Century

This chapter examines the challenges faced by digital informing technologies and civilization in the 21st century. The chapter begins by analyzing (1) the stages of development of strategic information technologies from the early 20th century up to the present as well as (2) the strategies adopted by informing science specializations (such as cognitive science, software engineering, etc.). Next, the chapter surveys major innovations in the history of strategic information technologies. This is followed by an analysis and evaluation of the concept of a laborless economy. The chapter concludes by positing a set of rules for workers in the digital economy that will ensure the wise development of civilization.

Generalized graphic-analytical model for evaluation of the fatality / structural collapse production mechanism on a building affected by an explosion

The paper highlights the generalized grapho-analytical model of analysis and evaluation of the mechanism of occurrence of the event scenario for the production of fatality/structural collapse in the case of a building affected by explosion. This mathematical model is based on research results in the field of civil explosives for the technological/occupational risks estimation and assessment, as well as threats to the security of protected areas that may be vulnerable through acts of malice. The process of quantitative risk assessment associated with explosion phenomena as a result of the detonation of an explosive charge, allows estimating result indicators based on the use of algorithms and models specific to associated hazards, in order to model the effects and consequences of event scenarios.