Simultaneous Optimization of Component Layout and Thermal Design for CubeSat under Limited Power Resources

2020 ◽  
Vol 68 (3) ◽  
pp. 97-107
Author(s):  
Yuki Koshiro ◽  
Ryu Funase
Author(s):  
Corinna Schmitt ◽  
Georg Carle

Today the researchers want to collect as much data as possible from different locations for monitoring reasons. In this context large-scale wireless sensor networks are becoming an active topic of research (Kahn1999). Because of the different locations and environments in which these sensor networks can be used, specific requirements for the hardware apply. The hardware of the sensor nodes must be robust, provide sufficient storage and communication capabilities, and get along with limited power resources. Sensor nodes such as the Berkeley-Mote Family (Polastre2006, Schmitt2006) are capable of meeting these requirements. These sensor nodes are small and light devices with radio communication and the capability for collecting sensor data. In this chapter the authors review the key elements for sensor networks and give an overview on possible applications in the field of monitoring.


2020 ◽  
Vol 8 (1) ◽  
pp. 18-24
Author(s):  
Tatsiana Shymanovich ◽  
John Z. Kiss

AbstractNASA is planning to launch robotic landers to the Moon as part of the Artemis lunar program. We have proposed sending a greenhouse housed in a 1U CubeSat as part of one of these robotic missions. A major issue with these small landers is the limited power resources that do not allow for a narrow temperature range that we had on previous spaceflight missions with plants. Thus, the goal of this project was to extend this temperature range, allowing for greater flexibility in terms of hardware development for growing plants on the Moon. Our working hypothesis was that a mixture of ecotypes of Arabidopsis thaliana from colder and warmer climates would allow us to have successful growth of seedlings. However, our results did not support this hypothesis as a single genotype, Columbia (Col-0), had the best seed germination, growth, and development at the widest temperature range (11–25 °C). Based on results to date, we plan on using the Columbia ecotype, which will allow engineers greater flexibility in designing a thermal system. We plan to establish the parameters of growing plants in the lunar environment, and this goal is important for using plants in a bioregenerative life support system needed for human exploration on the Moon.


2019 ◽  
Vol 88 ◽  
pp. 246-257 ◽  
Author(s):  
Yao Li ◽  
Cailian Chen ◽  
Shanying Zhu ◽  
Xinping Guan

Author(s):  
Hanne Cecilie Kavli ◽  
Heidi Nicolaisen ◽  
Sissel C. Trygstad

The growth in marginalized part-time work is a phenomenon often seen as part of an ongoing dualisation process in the labour market. Involuntary part-time is closely associated with marginalization. In Norway, the policy makers have tried to combat involuntary part-time work by introducing changes in the Working Environment Act (WEA). The intention was to make it easier for involuntary part-time workers to increase their working time. In this chapter, we focus on the Norwegian health care sector, a sector characterised by both part-time work and labour shortage. Drawing on in-depth interviews with employers and workers, we study if the WEA amendments have been effective in terms of providing increased working time for involuntary part-timers. Surprisingly, we find that the changes in the law seem to have produced unintended consequences at the workplace level. Our analysis suggest that some employers interpret the labour law changes as attempts to limit the managerial prerogative and adapt strategically to avoid its implications. This adaptation reduces the chance to escape involuntary part-time for low educated workers with limited power resources, while workers with higher education and a stronger bargaining position to a larger degree can benefit from the new regulations.


2013 ◽  
Vol 2 (4) ◽  
pp. 47-67
Author(s):  
Fady Medhat ◽  
Rabie A. Ramadan ◽  
Ihab Talkhan

Sensor nodes of Wireless Sensor Network (WSN) possess very limited power resources normally a battery and a solar cell could exist in some cases, which requires efficient usage of these resources to extend the network's lifetime. Accordingly, several research areas have been investigated to prolong the network longevity, Clustering was proposed to WSN as one of these areas that could help in decreasing the amount of consumed energy. A number of clustering algorithms were devised but to the authors' knowledge, this is the first work to consider clustering in Multimodal WSN, where a node can report more than one feature e.g. temperature and humidity. We compared the two general clustering algorithms K-Mean and Fuzzy C-Means to LEACH-C and LEACH, which are two clustering algorithms specially designed for WSN. Fuzzy C-Means and K-Means showed better performance using the techniques proposed in this work over LEACH-C and LEACH.


2015 ◽  
Vol 24 (03) ◽  
pp. 1550041 ◽  
Author(s):  
Muhammad Mazhar Abbas ◽  
Zia Muhammad ◽  
Khalid Saleem ◽  
Nazar Abbas Saqib ◽  
Hasan Mahmood

Ad hoc wireless networks are self-generating and self-organizing networks consisting of mobile and static nodes, which are small and have limited power resources. In a typical setup, these nodes communicate with each other through wireless medium and may act as source, destination and/or relaying nodes. As the power of the remote nodes is depleted very quickly, it is important to have a renewable energy source to support the network operations and increase lifetime. The availability of energy from the environment is unpredictable, random and uncertain, therefore energy harvesting with appropriate management plays an important role in continuous operations of ad hoc networks. In this paper, an energy harvesting and management model is presented for ad hoc networks. Along with harvesting energy, the proposed model ensures the connectivity requirements of the network for its perpetual operation.


1988 ◽  
Vol 2 (6) ◽  
pp. 303
Author(s):  
K.J.H. Hacke
Keyword(s):  

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