SECOND BIRTH OF TROPOSPHERIC COMMUNICATION. PHASED ANTENNA ARRAY COGNITIVE RADIO STATIONS

2020 ◽  
Author(s):  
Л.О. МЫРОВА ◽  
А.В. ШЕВЫРЕВ ◽  
С.А. МУСАЕЛЯН ◽  
И.С. ПОПОВ ◽  
В.А. ВОРОЩАК
Keyword(s):  
Cognitive Radio ◽  
Power Consumption ◽  
Low Power ◽  
Antenna Array ◽  
Radio Stations ◽  
Term Operation ◽  
Hardware Reliability ◽  
Phased Antenna Array ◽  
Technical Solutions

Рассмотрены новые прорывные технические решения по тропосферной связи на основе когнитивных радиостанций с фазированной антенной решеткой (ФАР). Показана возможность повышения (в десятки раз)аппаратурной надежности за счет исключения из состава ТРС мощных передатчиков и применения вместо них маломощных антенных приемопередающих модулей (АППМ),синфазноработающих в составе ФАР. Представлены преимуществами ТРС: возможность длительной работа без технического обслуживания, снижение вдвое энергопотребления, а также глубокая унификация построения ТРС разного класса на основе унифицированных АППМ. New breakthrough technical solutions for tropospheric communication based on cognitive radio stations with a phased antenna array (PAA) are considered. These solutions provide the possibility of increasing the hardware reliability tenfold due to exclusion of powerful transmitters from tropospheric stations (TS) and using instead of them low-power antenna receive-transmitting modules (ARTM), operating in phase as part of the PAA. The advantages of such TSs are shown that enable long-term operation without maintenance, halving power consumption, as well as deep unification of the construction of TSs of different classes based on unified ARTMs.

scholarly journals Hardware Reliability Analysis of a Coal Mine Gas Monitoring System Based on Fuzzy-FTA

2021 ◽  
Vol 11 (22) ◽  
pp. 10616
Author(s):  
Jingtian Xu ◽  
Man Yang ◽  
Shugang Li
Keyword(s):  
Reliability Analysis ◽  
Monitoring System ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Gas Monitoring ◽  
Hardware Failure ◽  
Minimum Path ◽  
Fuzzy Fault Tree Analysis ◽  
Hardware Reliability ◽  
Tree Method

The hardware reliability of a gas monitoring system was investigated using the fuzzy fault tree analysis method. A fault tree was developed considering the hardware failure of the gas monitoring system as a top event. Two minimum path sets were achieved through qualitative analysis using the ascending method. The concept of fuzzy number of the fuzzy set theory was applied to describe the probability of basic event occurrence in the fault tree, and the fuzzy failure probabilities of the middle and top events were calculated using fuzzy AND and OR operators. The results show that the proposed fuzzy fault tree is an effective method of reliability analysis for gas monitoring systems. Results of calculations using this method are more reasonable than those obtained with the conventional fault tree method.

scholarly journals Survivability of Ships at Sea: A Proposed Model to Account for Human Factors in a Safety-Critical System

2014 ◽  
Vol 156 (A2) ◽  
Keyword(s):  
Mathematical Model ◽  
Human Factors ◽  
Critical Incident ◽  
Emergency Situation ◽  
Probability Of Failure ◽  
Critical System ◽  
Safety Critical ◽  
Safety Critical System ◽  
Proposed Model ◽  
Hardware Reliability

Most serious accidents at sea are caused by minor incidents that escalated into an uncontrolled situation. This study is aiming to develop a model to investigate the likelihood of fatal accidents, given that a critical incident has already occurred. The focus of the study is on human behaviour, adopting a hardware reliability perspective. The vessel is considered as a safety-critical system to be protected by several barriers. The crew role is modelled as active barriers and distinguishing between different functions: perception, decision and action. A Markov approach is proposed to model different situations on the vessel. A mathematical model to estimate the probability of failure in an emergency situation is formulated. A new parameter is defined for the survivability of a vessel, given that a critical incident has taken place. The methods were applied to examine ship-platform collisions cases and the results show strong benefits for diagnosing and evaluating accidents from a human factors perspective as well as for training purposes.

Heating Pads: Human Factors Traps for Designers and Users

1983 ◽  
Vol 27 (9) ◽  
pp. 802-805
Author(s):  
Dieter W. Jahns
Keyword(s):  
Human Factors ◽  
Electric Heating ◽  
Hot Water ◽  
Human Factors Engineering ◽  
Functional Design ◽  
Therapeutic Application ◽  
Paradoxical Situation ◽  
Product Function ◽  
Hardware Reliability ◽  
User Instructions

Every year substantial amounts of property damage and numerous personal injuries result from failures of electric heating pads. This is a paradoxical situation considering that the intended product-function relates to the simple, safe, and reliable therapeutic application of heat to the human body. An investigation was conducted to determine whether traditional engineering criteria and human factors criteria were in conflict in the design of heating pads. The investigation revealed that the designers of heating pads have a tendency to overcome problems in hardware reliability by specifying how humans should behave relative to their product. Even heating pads that are Underwriters Laboratory (UL) listed contain user instructions which are unlikely to be followed under circumstances of normal use. The paper summarizes the functional design of heating pads, current instructions for their use, and applicable human factors considerations. An alternate approach to heating pad design is proposed which, if implemented, should prevent us from trading-in our heating pads for hot-water bottles. Beyond that, however, the paper serves as an example of how the application of human factors engineering principles can serve the goals of product safety and liability prevention.

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