Optimal design for long-term stable area-coverage satellite group orbit

2020 ◽  
Author(s):  
Benchang Zheng ◽  
Jinlei Ren ◽  
Zhenya Wang ◽  
Jun Li ◽  
Hu Huang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Area Coverage ◽  
Group Orbit ◽  
Stable Area

scholarly journals Dynamic Procurement under Uncertainty: Optimal Design and Implications for Incomplete Contracts

2016 ◽  
Vol 106 (11) ◽  
pp. 3238-3274 ◽  
Author(s):  
Malin Arve ◽  
David Martimort
Keyword(s):  
Optimal Design ◽  
Risk Aversion ◽  
Incomplete Contracts ◽  
Information Revelation ◽  
Firm Risk ◽  
Basic Service ◽  
Dynamic Contract ◽  
Risk Effect ◽  
Optimal Dynamic

We characterize the optimal dynamic contract for a long-term basic service when an uncertain add-on is required later on. Introducing firm risk aversion has two impacts. Profits for the basic service can be backloaded to induce cheaper information revelation for this service: an Income Effect which reduces output distortions. The firm must also bear some risk to induce information revelation for the add-on. This Risk Effect reduces the level of the add-on but hardens information revelation for the basic service. The interaction between these effects has important implications for the dynamics of distortions, contract renegotiation, and the value of incomplete contracts. (JEL D47, D81, D86)

scholarly journals Evaluation of snow extent time series derived from Advanced Very High Resolution Radiometer global area coverage data (1982–2018) in the Hindu Kush Himalayas

2021 ◽  
Vol 15 (9) ◽  
pp. 4261-4279
Author(s):  
Xiaodan Wu ◽  
Kathrin Naegeli ◽  
Valentina Premier ◽  
Carlo Marin ◽  
Dujuan Ma ◽  
...  
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Land Cover ◽  
Snow Cover ◽  
Area Coverage ◽  
Slope Aspect ◽  
Hindu Kush ◽  
Very High

Abstract. Long-term monitoring of snow cover is crucial for climatic and hydrological studies. The utility of long-term snow-cover products lies in their ability to record the real states of the earth's surface. Although a long-term, consistent snow product derived from the ESA CCI+ (Climate Change Initiative) AVHRR GAC (Advanced Very High Resolution Radiometer global area coverage) dataset dating back to the 1980s has been generated and released, its accuracy and consistency have not been extensively evaluated. Here, we extensively validate the AVHRR GAC snow-cover extent dataset for the mountainous Hindu Kush Himalayan (HKH) region due to its high importance for climate change impact and adaptation studies. The sensor-to-sensor consistency was first investigated using a snow dataset based on long-term in situ stations (1982–2013). Also, this includes a study on the dependence of AVHRR snow-cover accuracy related to snow depth. Furthermore, in order to increase the spatial coverage of validation and explore the influences of land-cover type, elevation, slope, aspect, and topographical variability in the accuracy of AVHRR snow extent, a comparison with Landsat Thematic Mapper (TM) data was included. Finally, the performance of the AVHRR GAC snow-cover dataset was also compared to the MODIS (MOD10A1 V006) product. Our analysis shows an overall accuracy of 94 % in comparison with in situ station data, which is the same with MOD10A1 V006. Using a ±3 d temporal filter caused a slight decrease in accuracy (from 94 % to 92 %). Validation against Landsat TM data over the area with a wide range of conditions (i.e., elevation, topography, and land cover) indicated overall root mean square errors (RMSEs) of about 13.27 % and 16 % and overall biases of about −5.83 % and −7.13 % for the AVHRR GAC raw and gap-filled snow datasets, respectively. It can be concluded that the here validated AVHRR GAC snow-cover climatology is a highly valuable and powerful dataset to assess environmental changes in the HKH region due to its good quality, unique temporal coverage (1982–2019), and inter-sensor/satellite consistency.

Optimal Design for Biodiesel Supply Chain: Case Study

2021 ◽  
Author(s):  
Fitriani Tupa R Silalahi ◽  
Togar M. Simatupang ◽  
Manahan Siallagan
Keyword(s):  
Supply Chain ◽  
Renewable Energy ◽  
Optimal Design ◽  
Chain Process ◽  
Supply Chain Costs ◽  
Decision Variables ◽  
Supply Chain Process ◽  
Do So

One renewable energy form currently being promoted is that of biodiesel as a substitute for diesel fuel. This involves mixing biodiesel with petrodiesel in proportions governed by the respective regulations of each country. The purposes of this research are to support the exploiting of biodiesel forms of renewable energy and to optimize the palm oil-sourced biodiesel supply chain by conducting an Indonesia-based case study. The optimization process was implemented in accordance with the government's mandate and long-term planning. There are two decision variables to consider. First, the model will identify the optimum delivery point locations as a blending terminal between biodiesel and petrodiesel (petroleum diesel). Second, it will determine the location of biodiesel plants’ construction in order to satisfy the government's mandate. The results show that, while determining delivery point locations affects supply chain costs, it does not do so significantly. More influential is determining the construction locations of biodiesel plants and this study provides a model for deciding the delivery points and locations of biodiesel plants in order to minimize biodiesel supply chain costs in Indonesia. This study presents in detail biodiesel supply chain process in Indonesia and based on the literature, no research was found on studying optimization biodiesel supply chain in Indonesia.  

scholarly journals Long-Term Area Coverage and Radio Relay Positioning Using Swarms of UAVs

2019 ◽  
pp. 81-98
Author(s):  
Floriana Benedetti ◽  
Alessio Capitanelli ◽  
Fulvio Mastrogiovanni ◽  
Gianni Viardo Vercelli
Keyword(s):  
Area Coverage ◽  
Relay Positioning

Design of Semiautomatic Standardizing Machines for Load Cells Testing

1976 ◽  
Vol 98 (1) ◽  
pp. 124-130
Author(s):  
Adam Morecki ◽  
Wiktor Narkiewicz ◽  
M. A. Townsend
Keyword(s):  
Optimal Design ◽  
Mechanical System ◽  
Load Cells ◽  
Systematic Synthesis

The paper deals with the systematic synthesis of semiautomatic standardizing machines used for load cells testing. The principal requirements are formulated and an evolutionary (such as followed in optimal design) is given. Of special note is the extreme accuracy required (0.01 percent) and acheived in a relatively large mechanical system. The paper includes some results of analyses made for two types of machines and data obtained from tests and long-term utilization of these machines.

scholarly journals Urgently Needed: Climate Lawyers

Climate Law ◽  
2018 ◽  
Vol 8 (3-4) ◽  
pp. 161-171
Author(s):  
Michael Faure ◽  
Jing Liu
Keyword(s):  
Climate Change ◽  
Optimal Design ◽  
Greenhouse Gases ◽  
Environmental Law ◽  
Paris Agreement ◽  
Long Term Effects ◽  
Adaptation To Climate Change ◽  
International Policy ◽  
Policy Arena

We argue that climate law has specific features—including scientific complexity, a strongly transboundary nature, and long-term effects—that make it more challenging to study than other more traditional domains of environmental law. As a consequence, an interdisciplinary perspective may be needed even more for climate law than for the traditional study of environmental law. Climate law is to some extent underestimated by scientists, who should realize that for effective mitigation of greenhouse gases and adaptation to climate change, an optimal design and enforcement through climate law is necessary. Climate law can be expected to become more important with the implementation of the Paris Agreement, and for that reason climate lawyers should receive a more prominent position in the international policy arena of climate change.

Long-Term Thermomechanical and Thermohydrological Factors Controlling the Optimal Design of a Nuclear Waste Repository

1982 ◽  
Vol 15 ◽  
Author(s):  
J. S. Y. Wang ◽  
D. C. Mangold ◽  
C. F. Tsang
Keyword(s):  
Optimal Design ◽  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Horizontal Gradient ◽  
Major Mechanism ◽  
Surface Uplift ◽  
Generic Modeling ◽  
Waste Repository ◽  
Waste Loading

ABSTRACTSurface uplift and buoyancy flow are two of the major long-term, far-field perturbations to the geologic formations around a nuclear waste repository. The allowable surface uplift has been accepted in the literature as a criterion limiting the repository waste loading density. It has also been recognized in generic modeling studies that the buoyancy distortion of the ambient groundwater flow around a repository is a major mechanism for radionuclide transport. However, the buoyancy considerations have yet to be quantified for the purpose of optimal design of a radioactive waste repository. We suggest the possibility of using the buoyancy gradient when compared with the ambient regional (horizontal) gradient as a measurable thermohydrologic factor that controls the design of waste loading. This study indicates that the buoyancy gradient could in some cases become the main controlling factor. To decrease the buoyancy effects, much lower values of waste loading density should be considered in the design of the waste repository.

What Factors Contributed to the Torrential Rainfall of Hurricane Harvey over Texas?

2020 ◽  
Vol 15 (6) ◽  
pp. 726-734
Author(s):  
Satoshi Iizuka ◽  
◽  
Naoki Sakai
Keyword(s):  
Tropical Cyclone ◽  
Residence Time ◽  
Rainfall Intensity ◽  
Extreme Rainfall ◽  
Rainfall Rate ◽  
Area Coverage ◽  
Lower Atmosphere ◽  
Central Coast ◽  
Torrential Rainfall

In August 2017, Hurricane Harvey brought an unprecedented amount of rainfall and catastrophic flooding to the Houston metropolitan area, as it stalled near the coast of Texas for several days after weakening to a tropical storm intensity. The present study examines the relationship between tropical cyclone rainfall totals over Texas and the track, residence time, rainfall intensity, and rainfall area coverage of past tropical cyclones that approached Texas after 1979. The most significant factor affecting rainfall totals over Texas is whether a tropical cyclone makes landfall on the central coast of Texas and travel inland. Another significant factor is the length of time a tropical cyclone resides near Texas. Rainfall intensity also contributes in part to rainfall totals over Texas, whereas contribution of rainfall area coverage is not significant. The track of a tropical cyclone traveling near Texas is controlled by the steering winds over Texas, while its residence time near Texas is related partly to the meandering of the subtropical jets. Rainfall rate depends on the intensity of tropical cyclone. No significant relationship between rainfall intensity and environmental moisture in the lower atmosphere is found in the present analysis. Furthermore, the extreme rainfall totals over Texas induced by Harvey can be attributed to the combined effect of extreme long-term stalling of Harvey near the central coast of Texas and the higher rainfall rate.

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