NETWORK PERFORMANCE IMPACTS ON OPERATORS IN SAFETY-CRITICAL SYSTEMS

2006 ◽  
Vol 05 (01) ◽  
pp. 173-194 ◽  
Author(s):  
TUNCAY BAYRAK ◽  
MARTHA R. GRABOWSKI

Safety-critical wide area networks are comprised of human and technical elements cooperatively performing tasks in a safety-critical setting. In such settings, both human and technical dimensions are critical in performance evaluation. It is the relationships between changes in network performance and their impacts on human operator performance with safety-critical wide area networks that we investigate in this research. The paper begins by examining the theoretical background for this research, and then describes the research model. It was found that decreases in network reliability were associated with expected degradations in operator satisfaction, operator confidence, and increases in operator workload. Likewise, it was found that an increased number of network tasks processed was associated with a decrease in operator accuracy and decreased operator communication. The results of this study suggest that understanding the impact of the network performance on human performance is important in safety-critical settings employing wide-area networks.

Author(s):  
FNU Varun Ananthasivan Srikrishnan ◽  
Richard T. Stone ◽  
Cong Xu

Over the past few years, an extensive amount of research has been done in the field of Human Factors. Applications range from the design of day-to-day products like cell phones to the design and development of safety-critical systems like flight displays. The highly critical aviation industry has shown time and again the importance of human-centered approach in developing systems for the safety of those operating it and the passengers. Similarly, other safety-critical industries like law enforcement have been seen to incorporate human factors in the design of weapons and exoskeletons aimed at adapting to humans and making their unit stronger. Many manufacturing firms have begun to see the importance of proper work postures for their employees to avoid musculoskeletal disorders and the financial and regulatory implications of not following proper work ethics that take care of employees’ health. Further, many organizations have started to consider team dynamics in their operations understanding the importance of healthy interaction among the employees and between employees and the management. However, there are a very few references to any studies or organizational practices that draw a connection between human performance and human-centric re-design of work places, with most designs being limited to work desks and activity-based working (ABW) work spaces. This paper focuses on the organizational engineering of storage spaces to enable easy location and retrieval of equipment, thus supporting the time-critical nature of operations at a miscellaneous storage room at the Story County Sheriff’s Office. Experiments were carried out using two familiar scenarios both before and after the redesign of the storage room. A significant improvement in the performance of the operator was observed after the redesign, as could be seen by the reduction in time taken to identify and retrieve equipment and the qualitative survey that was obtained at the end of the experiment. The wasted time was translated to a cost and the newly designed storage design saved a significant amount of money spent on actions that precluded efficient accomplishment of tasks, something that could have been used by the Sheriff’s office to purchase equipment for normal operation of the office. The results suggested such interventions in different sectors that have similar high-priority operations. The results of the study indicates that there is a need for the industry to extend research towards this field that we name “organization engineering”.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Soultana Ellinidou ◽  
Gaurav Sharma ◽  
Théo Rigas ◽  
Tristan Vanspouwen ◽  
Olivier Markowitch ◽  
...  

In recent years, Multi-Processor System-on-Chips (MPSoCs) are widely deployed in safety-critical embedded systems. The Cloud-of-Chips (CoC) is a scalable MPSoC architecture comprised of a large number of interconnected Integrated Circuits (IC) and Processing Clusters (PC) destined for critical systems. While many researches have focused on addressing the hardware issues of MPSoCs, the communication over them has not been very well explored. Following the SDN concept, we propose a new protocol in order to secure the communication and efficiently manage the routing within the CoC. The SSPSoC includes a private key derivation phase, a group key agreement (GKA) phase, and a data exchange phase in order to ensure that basic security primitives are preserved and provide secure communication. Furthermore, a network of 1-30 nodes is set in order to validate the proposed protocol and measure the network performance and memory consumption of the proposed protocol.


2020 ◽  
Vol 13 (4) ◽  
pp. 268-280
Author(s):  
Istvan Drotar ◽  
Balazs Lukacs ◽  
Miklós Kuczmann

There are several types of wireless IoT (Internet of Things) networks based on the connection distance between two communicating devices. For covering wide areas, LPWAN (Low Power Wide Area) networks can provide a good solution. These networks provide big coverage and low power consumption. One of the most popular LPWAN network is LoRaWAN (Long Range Wide Area Network). LoRaWAN networks are ideal for sending infrequent, small messages through long distances. In this article the network’s capacity, coverage and energy consumption have been tested. These are the most important attributes when designing a LoRaWAN network, so it can satisfy the requirements of LPWAN networks.


2021 ◽  
Vol 9 ◽  
Author(s):  
Shuran Liu ◽  
Meng Cheng ◽  
Qinhao Xing ◽  
Yizhe Jiang ◽  
Qianliang Xiang ◽  
...  

One of the key challenges facing distribution network operators today is the expected increase in electric vehicles. The increased load from EV charging will result in distribution assets becoming “thermally overloaded” due to higher operating temperatures. In addition to the issue of increased load, we have a limited understanding of the behavior and performance of the distribution assets and their potential to accept the increased load. It has been well acknowledged that EVs increase the network loading level, leading to a reduced system reliability performance. These results have not been quantified in a realistic case study, including actual cable rating and design properties. To address this gap, this paper proposes a novel methodology in the existing power network reliability evaluation framework, which quantifies the impact of different EV penetration levels on distribution network reliability, and the thermal performance of distribution cables. Novel approaches using smart switching technology and emergency uprating are proposed to reduce the peak power demand caused by EVs, in order to reinforce the reliability of the grid and to boost the maximum allowable EV penetration in the distribution networks. The methodology was applied using a case study on the modified EV-integrated RBTS (Roy Billinton Test System) bus four distribution network. The results showed that the negative impact of EVs on network performance can be mitigated by the implementation of smart switching technology. The peak demand under contingencies can also be accepted by the cables though emergency uprating. The frequency and duration of EV demand interruption was also significantly reduced. Thus, a higher EV penetration can be accommodated.


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