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Understanding the change of river islands is essential for water conservancy construction, channel navigation safety, and industrial/agricultural production. Yangtze River is the largest river in China; however, there are few long-term monitoring results on the changes of Yangtze River islands. To fill this gap, Landsat data available on the Google Earth Engine (GEE) were used to obtain the annual changes of the Yangtze River islands located from the lower reaches of the Three Gorges Dam (TGD) to the Yangtze River delta during 1986-2017. Moreover, we focused on the changes of those islands before and after the construction of the TGD. Annual areas of all river islands were calculated and spatial-temporal pattern of Yangtze River islands were analyzed. Our satellite observation results show continuous expansions of Yangtze River islands after the construction of the TGD in 2003. For the total 138 river islands, in three stages: before 2003, after 2003 and in the 32-year study period, 68, 118, and 124 river islands showed increasing trends, with the net increase of 286.47 km2, 417.49 km2, and 665.62 km2. For the total 92 river island groups (138 islands), percentages of river island expansion are 41.30% (before 2003), 80.43% (after 2003) and 88.04% (1986-2017). Moreover, we found 10 newly developed river islands, with a net expansion of 87.42 km2 and an expansion rate of 2.73 km2/year. The significant decrease (2-4 m) in water level before and after the TGD might be the main factor that results in the observed expansion of Yangtze islands downstream the TGD. We also highlighted the importance of using all available Landsat imagery for tracking the changes of river islands. Our satellite-derived dataset provide reference data for the land use planning and environmental protection in the Yangtze River drainage basin.

The existing statistics of the Antarctic ionosphere parameters behavior is supplemented by the results from the Livingston station data for the summer periods of 2005–2019, 35 months in total. The climatology of the parameters behavior came to the constancy of the values of the critical frequency foF2 in the local daytime and evening times and significant differences at night, reaching factor 2. The highest values are in December, the lowest in March. For the maximum height hmF2, the spread of values is small. A comparison of the values of foF2 and hmF2 of the IRI model with observational data is carried out. A certain tendency of an increase in deviations with an increase in solar activity was found. For foF2, dispersion σ does not exceed 25%, for hmF2 −17%. The average values for the entire period are: $\vert\Delta \text{foF}2\vert=0.73$ MHz, σ(foF2) =0.86 MHz and 13.6%, $\vert\Delta \text{hmF}2\vert=22.5$ km, σ(hmF2)=27.5 km and 9.65%. These magnitudes are close to those for stations in the northern hemisphere. The possibility of using the total electron content for determining foF2 is shown.

Large scale land cover data is an important basis for global land surface process research, ecosystem assessment, environmental modeling and other scientific research. Studying the characteristics of existing data sets has guiding significance for data users and the production of new data sets. Taking nine urban agglomerations (Yangtze River Delta Urban Agglomeration, Beijing Tianjin Hebei Urban Agglomeration, Guangdong-Hong Kong-Macao Greater Bay Area, Northwest Urban Agglomeration, Japan’s Pacific Coastal Urban Agglomerations, Greater London Urban Agglomeration, West Coast Urban Agglomeration, Atlantic Coast Urban Agglomeration and Great Lakes city Urban Agglomeration) as the study area, this study analyzed the spatial consistency of four land cover datasets, namely, GlobeLand30, FROM-GLC, GLCFCS30 and CCI-LC and evaluated the accuracy of the four land cover datasets using Google Earth high-resolution images. The results show that the spatial distribution patterns of the same land cover features in different land cover data sets are quite different, and the overall consistency coefficient among different land cover data sets is low; FROM-GLC has the highest overall precision and kappa coefficient, while CCI-LC has the lowest overall precision and kappa coefficient.

The spatiotemporal fractional vegetation cover (FVC) variations from 2000 to 2020 in the Changjiang basin, China, were studied. With Google Earth Engine (GEE), thousands of Landsat-5, 7, and 8 images were analyzed. In 2000, 2010, and 2020, the FVC increased roughly from the west to the east, crossing the basin. The low FVC areas were mainly around the Qinghai-Tibet Plateau and Changjiang Delta. The basin was well-vegetated from 2000 to 2020, with a minimum yearly average FVC of 67.45%. The FVC increased. At the pixel level, 60.14% of locations had a positive slope of the FVC versus time. Thus, the ecological environments assessed by FVC were healthy for the last 20 years, and the health improved. As shown in this study, GEE is an efficient and effective platform to study natural environments and environmental changes at a large spatial extent and over a long time.

The Colorado River of Texas is the longest river within Texas. The evolution of its delta is completely controlled by human intervention. To map the evolution of the delta, this study investigates suitable classification methods by WorldView 2 images. Deep learning methods such as UNet recently have made great progress in remote sensing image classification. sensing. This paper explored good practices of UNet remote sensing application for the estuary and coastal environment. This paper also discussed data augmentation for remote sensing.

Due to the Coronavirus Disease (COVID-19) pandemic, the human activities in China and even in the world were reduced in 2020, which also caused the variation of the atmospheric environment, especially atmospheric aerosol emissions. In this paper, the MODIS level-3 gridded atmosphere monthly global joint product in 2019 and 2020 were collected and processed. After preliminary analysis, we found that MODIS annual aerosol optical depth (AOD) over China in 2020 is generally lower than in 2019. In some regions such as Beijing-Tianjin-Hebei and Yangtze River Delta, AOD values dropped the most in February. However, in some months and regions, AOD in 2020 is even higher than in 2019. More studies are still ongoing.

This paper presents a method for Wye-Delta and Delta-Wye transformations of proximally-coupled inductor triads. This is achieved by a two stage process: a topology-preserving ‘deproximation’ that produces an intermediate coupling-free network which retains the same structure, thus making it possible to apply a straightforward transformation. The developed method is illustrated via numerical examples.

In AOMedia Video 1 (AV1), directional intra prediction modes are applied to model local texture patterns that present certain directionality. Each intra prediction direction is represented with a nominal mode index and a delta angle. The delta angle is entropy coded using shared context between luma and chroma, and the context is derived using the associated nominal mode. In this paper, two methods are proposed to further reduce the signaling cost of delta angles: cross-component delta angle coding, and context-adaptive delta angle coding, whereby the cross-component and spatial correlation of the delta angles are explored, respectively. The proposed methods were implemented on top of a recent version of libaom. Experimental results show that the proposed cross-component delta angle coding achieved average 0.4% BD-rate reduction with 4% encoding time saving over all intra configurations. By combining both methods, an average 1.2% BD-rate reduction is achieved.

Soil salinity and alkalinity is an important index concerned by planting industry. In order to meet the demand of long-term observation of soil salinity and alkalinity in precision agriculture and eco-environmental protection, and to solve the current pain points of long sampling period and high cost of soil salinity measurement, this paper designs and implements an online monitoring system for soil salinity alkalinity in tideland in the Yangtze River Delta for crop planting and soil remediation. This system uses solar power supply system and maintenance-free digital sensor, which can be arranged in monitoring area for a long time to collect soil temperature, humidity and salinity data. The collected data can be stored in SD card locally and transmitted to cloud server in real time through 4G network. Up to now, the system has been running stably for nearly two years under the condition of unattended and maintenance free. More than 30000 soil salinity data have been collected from 5 monitoring points, which can be used for long-term observation of the interaction between salinity and plant growth, so as to improve the soil and improve the quality of agriculture products.

As a significant improvement in the quality of transportation infrastructure, high speed rail significantly improves the regional accessibility and makes the allocation of production factors in a wider range, which has an important impact on urban development. Taking the Yangtze River Delta Urban Agglomeration as an example, this paper uses the Difference-in-Difference model to analyze the impact of high speed rail construction on the urban development gap, which based on the data of prefecture level cities from 2001 to 2018. The results show that the opening of high speed rail is conducive to narrowing the development gap of cities in the Yangtze River Delta. The reason may be that the high speed rail accelerates the trend of industrial transfer within the urban agglomeration, thus promoting the development of regional integration. Secondly, from a local point of view, the polarization effect still exists in the Yangtze River Delta, but the scope of polarization is shrinking, and it gradually moves to the lower level along the gradient of urban development. Finally, the analysis of the lag effect shows that the impact of high speed rail on narrowing the urban development gap is continuous, and with the increasing improvement of the high speed rail network, this impact has a gradually increasing trend, which is of great significance to the balanced development of the Yangtze River Delta.

The Yangtze River Delta urban agglomeration is located in East China, which is an important starting point for the "Belt and Road" Initiative and the leader of the Yangtze River Economic Belt. High expectations are placed in the socialist modernization drive and the economic layout of opening up. As the most developed region of China’s economy, and also China’s largest foreign trade export base, foreign trade has always played an irreplaceable role in its economic development. This paper first analyses the current situation of foreign trade development in Jiangsu, Zhejiang, Anhui and Shanghai, then uses the dominant comparative advantage index, export similarity index to analyze the competitiveness of foreign trade in three provinces and one city. Subsequently, the paper adopts the trade combination index, trade specialization index to analyze the complementarity situation of foreign trade between the Yangtze River Delta and its main trading partners, and on this basis. At last, some relevant ccountermeasures and suggestions are put forward.

Our paper analyzes the implementation of an eco-driving training for truck drivers in a Vietnamese logistics service provider, Delta International Ltd. Eco-driving, despite already well acknowledged ecological and economic benefits among developed countries, remains scarcely adopted by Vietnamese drivers. Since April 2018, while still concerned by excessive CO2 emission and logistics costs due to fuel consumption of its truck fleets, Delta has become a logistics pioneer by encouraging Delta's drivers to adopt eco-driving techniques into real conditions. By training Delta's drivers to eco-driving practices and by rewarding them extra income based on the value of saved fuel, Delta International Ltd has chosen an original path that inquires its possible diffusion among other Vietnamese 3PL. We adopt a qualitative approach based on interviews with Delta's CEO, Delta's drivers and about twenty Vietnamese 3PL to estimate whether Delta's eco-driving model may be adopted by other Vietnamese 3PL. We also illustrate the experiences, the highlights, and the drawbacks of Delta's eco-driving strategy.

In the present study, we have measured Black Carbon (BC) mass concentration over Ahmedabad city during the year 2017 and 2018. The measurements of BC have been carried out at various locations of the city during winter, summer, and post monsoon seasons. The concentration of black carbon has been found high in industrial areas and traffic junctions. In 2017, the measured high black carbon concentration was 80.73 µg/m3 and in 2018, it has increased to 83.7 µg/m3. Delta C value generally indicates wood burning as a BC source and its value is up to 20.38 µg/m3 in Ahmedabad during 2017-18. This study is helpful to estimate the major hotspots of BC mass concentration over the city and we have tried to find the major contributors to BC emission.

In this study, ground measurements of Black Carbon (BC) concentration were collected at different locations in Gandhinagar at two different times morning and evening, the capital city of Gujarat, during Post-monsoon season for year 2017 and 2018. Delta C and Absorption Angstrom Exponent (AAE) were calculated to identify the possible sources. During study, we observed a decrease of 51.7% in BC concentration in year 2018 compared to year 2017. Regions with heavy vehicle traffic shows high BC values especially during evening time. Occurrence of high Delta C and AAE are indicative of enhanced absorption in near-UV and low-visible wavelengths attributed to the presence of biomass burning and light absorbing particulate matter.

Satellite imagery provides a lot of information that can be analysed for a variety of objectives. The vegetation analysis in a region for a particular period of time to process a large amount of data is remaining as a bottleneck and involves a series of timeconsuming steps that delay the output. To overcome this challenge, this study aims to automate the process and estimate the area of sparse and dense vegetation of a certain area of interest and to assess the vegetation dynamics in this region by using the Sentinel-2 data. Python with its opensource libraries are utilized for downloading and processing the satellite data. Mandal (sub-district) level Mean NDVI, area under sparse and dense vegetation are estimated at the peak vegetative growth stage in Rabi season (February) from 2017 to 2020. In the assessment of satellite data, it was observed that the Godavari delta region has shown a decrease in the sparse vegetative area (11094 ha.) and an increase in dense vegetation area (3272 ha.) in 2018 as compared with 2019 assessment. However, in the Krishna delta region, it was observed that the sparse vegetation area was decreased (90600 ha) and an increased dense area (161915 ha.) in 2020 as compared with 2017. The process involves downloading Sentinel-2 data using SentinelHub and SentinelSat API, pre-processing and segmenting NDVI images to classify vegetation areas and the calculation of Mandal (sub-district) level statistics.

In the paper, a three-phase Delta-Delta LLC resonant converter is introduced. Furthermore, the characteristics of resonant tank without or with phase-shedding are analyzed based on FHA method. Finally, the performance of a 16kW DC/DC converter designed for 750V input and 150V output is evaluated and peak efficiency up to 98.9% is implemented.

Using the data from 2004 to 2019, this paper constructs the panel data model to conclude that there are differences in the impacts of functional division on the economic growth of different urban agglomerations: the order of the driving forces of functional division on economic growth is: Beijing-Tianjin-Hebei > Pearl River Delta > Yangtze River Delta > Guanzhong Plain > Middle Reaches of Yangtze River. The economic growth effect of the functional division of eastern urban agglomeration is more significant, which further widens the economic gap between the eastern urban agglomeration and other urban agglomerations.

Speaker verification based on deep speaker embeddings (DSE) network outperformed traditional i- vectors systems. Afterward, to improve the performance, various researches have been conducting and data augmentation methods are one of them. In this paper, we focus on acoustic delta features augmentation and their aggregation methods for DSE networks, X-vectors and MobileVoxNet. For CNN-based MobileVoxNet, we re-design the architecture to aggregate delta features in deeper layer with squeeze and excitation (SE) module. Experimental results show that the proposed methods achieve performance improvement compared to not using delta features on the VoxCeleb1 test dataset. We also compare the number of computations and parameters of models to analyze efficiency of the proposed methods.

SAR tomographic methods have proven extremely adept at measuring vegetation vertical structure at a variety of wavelengths including L and P-bands. The three dimensional structure of vegetation and its changes resulting from either natural or anthropogenic causes are key parameters in monitoring ecosystems. The NASA/JPL UAVSAR collected data at L and P-bands at Delta Junction, Alaska in September of 2017 whereas the NASA/JPL UAVSAR and DLR F-SAR acquired data at the BERMS site near Saskatoon, Canada on August 19 and 23 of 2018 respectively. Tomographic data sets were collected at L-band and P-band by the NASA/JPL UAVSAR at Delta Junction and at L-band at BERMS and DLR F-SAR acquired data at L-band and S-band. Ground truth data sets and lidar data from the NASA LVIS system were also acquired at BERMS. We compare L and P tomography at Delta Junction and L-band and S-band tomography from the two systems to each other and to the lidar data sets at BERMS. These data are then used to estimate biomass and assess spatial gradients in the canopy vertical structure. We also compare our data with simulated boreal forest data to assess the sensitivity to the data collection geometry and canopy parameters.

In Indonesia, most of the territorial waters are dominant occur ship accidents. One of the causes of ship accidents is the ship's electrical system that is carried out by human error worker performance, and also as a cross-ship on. According to the NTSC information, ship damages is more than 41% caused by human factors (human error). The purpose of this research was taken from the MT Delta Victory tanker ship to be able to analyze the size of the value of the human factor that affects the tanker's accidental sensitivity. In this study the method taken from this AHP by combining with the Shell Model to determine the value of its human error. The results of the study that the MT tanker accident. Delta Victory with damage from the ship's electrical system which is attributed to the human error factor is 12.7% and 17.2% which are not applied SOP. Therefore, it is necessary to plan SOP to reduce ship accidents.

In this study, semi-layer delta-type networks operating under the cut-through forwarding technique are selected as the test-bed subject for data-rate evaluation when packet arrivals follow hotspot patterns. This specific and promising network is modelled, analysed and simulated. The results demonstrate in a quantitative manner the productivity of the fabric studied, highlighting the benefits of its use of both fan-out and the embedded cut-through mechanism.

It is well known, the activates of resting-state functional networks (RSNs), including the brain default-mode network (DMN) and the central executive network (CEN) is associated with inclination to various mental disorders in humans. At this study, it can be assumed that both the process of adaptation to the polar climate and new social conditions, and the gradual reduction of the risk of depression among migrants, are due to functional changes within these two brain systems, as well as their functional relationships among themselves. Hypothetically, the increased activity of CEN is connected with a higher level of stress associated with moving to new living conditions, whereas the increasing activation of posterior hub of DMN is associated with higher risk of depression.

The constellation and orbit design problem for Distributed Spacecraft Missions is challenging due to the extremely large space of alternatives, the presence of multiple conflicting objectives, and the expensive evaluation functions required to assess these objectives. Prior work in the literature has typically constrained this problem to simple constellation patterns that generally provide good coverage performance, such as the homogeneous Walker Delta pattern. However, this ignores potentially good architectures formed by heterogeneous constellations mixing satellites at different altitudes and inclinations. Thus, this paper studies methods to explore this region of the constellation design space which is understudied and has potential to be a cost-efficient way of satisfying regional coverage requirements and solving orbit design problems with disjoint areas of interest. We adopt a framework based on multi-objective evolutionary algorithms, which have been used extensively in the literature to solve similar problems due to their ability to deal with mixed-integer problems with highly non-linear and nonconvex objective functions such as the numerical simulations required to compute coverage performance for multi-satellite systems. Moreover, we focus on formulations (i.e., chromosomes and operators) rather than algorithmic details, since it is well known that formulations are at least as critical in driving performance as the details of the optimization algorithm used itself. Specifically, we explore two new formulations for heterogeneous constellation design: (1) A fixed-length chromosome containing $m$ 5-tuples, which encode a hybrid architecture with a fixed number of $m$ Walker constellations at different altitudes and inclinations, where each constellation is defined by a 5-tuple consisting of altitude, inclination, number of satellites, number of planes and relative spacing parameter. In this formulation, the number of satellites in each constellation can be set to 0 to effectively reduce the number of constellations. (2) A variable-length chromosome, which encodes a heterogeneous constellation defined by the total number of satellites n and $p$ 2-tuples, where each plane is defined by a 2-tuple consisting of its altitude and inclination and includes $n$ / $p$ satellites. All planes are assumed to be equally spaced in RAAN and satellites within a plane are equally spaced in mean anomaly. These two formulations are compared to a third formulation proposed earlier in the literature, which consists of a variable-length chromosome containing $n$ 4-tuples to encode a constellation of $n$ satellites, where each satellite is defined by a 4-tuple with its altitude, inclination, RAAN, and mean anomaly. The performance of these formulations is compared by solving a constellation design problem where the objectives are to optimize coverage performance and lifecycle cost. Search performance is assessed by looking at the evolution of hypervolume with the number of function evaluations. The formulations discussed in this paper were developed in the context of a NASA-funded project to develop a tool called Tradespace Analysis Tool for Constellations using Machine Learning (TAT-C ML). This tool is intended to be used during early stages of the design of Earth observation missions, and it is planned to be released open source within the next year.

NASA's Parker Solar Probe (PSP) mission will revolutionize our understanding of the Sun by traveling through the Sun's atmosphere, closer to the surface than any spacecraft before it, to provide humanity with the closest-ever observations of a star. The PSP spacecraft was designed, built, and operated by the Johns Hopkins Applied Physics Laboratory (APL). A successful launch of the spacecraft occurred on August 12, 2018 from Cape Canaveral, Florida on a Delta IV Heavy launch vehicle using an additional upper stage. This paper describes the development and execution of the launch countdown procedure that was used by the APL spacecraft Integration and Test (I&T) team to prepare the spacecraft for launch. Specific aspects of the complex spacecraft design are introduced where these led to unique driving requirements for the countdown process. The nominal countdown activity timeline is reviewed, and spacecraft contingency procedures are presented that were developed for use in the event of a hold, recovery, recycle, or scrub. Associated test scripts and telemetry display pages specific to the spacecraft countdown are also discussed, as well as pre-launch testing and launch rehearsals. Finally, an overview is provided of spacecraft countdown operations during two launch attempts on back-to-back days. This sequence challenged the spacecraft team to exercise a range of countdown contingency procedures, both to resolve technical issues with the spacecraft ground systems and to support launch vehicle scrubs and recycles. All spacecraft countdown operations were ultimately completed successfully, culminating in the successful launch of PSP.

On August 12, 2018, NASA and the Johns Hopkins Applied Physics Laboratory (APL) successfully launched Parker Solar Probe (PSP) on a mission to study the Sun, as part of NASA's Living With a Star program. As of this writing, the spacecraft has successfully completed its third close approach to the Sun and is returning new data to scientists here on Earth. The journey leading up to this point was difficult and full of many unique challenges. PSP will be flying within the corona of the sun over twenty times and traveling more than seven times closer than any spacecraft has come before (1). PSP was designed to withstand intense heat by sitting behind a first-of-its-kind Thermal Protection System (TPS), while still being able to perform all of its necessary functions. This mission required an extensive knowledge base and multiple teams working in conjunction to bring this flight to fruition. This paper will discuss some of the many difficult integration and test challenges faced leading up to launch; their origin, development, and steps that the team executed to overcome them and ensure success. The spacecraft was exceptionally complex, with multiple systems that were redundant, and required an extremely large portion of the schedule to be dedicated to testing. The Autonomy system had to be very robust as the mission is designed to have large periods of time where the spacecraft will be out of contact with the Earth. PSP was also mass constrained; all of the systems had to fit into a relatively small bus that restricted the integration order of operations and limited the amount of activities that could be performed in parallel. Due to these numerous challenges, the team had to be very flexible and adaptable to the needs of the spacecraft and the mission. From the integration of the bus at APL, to environmental testing at the Goddard Space Flight Center, to the final pre-flight processing at Astrotech Space Operations and on the Delta IV Heavy launch vehicle at the Cape Canaveral Air Force Station, PSP was a learning experience every step of the way.

There is currently a trend towards developing and commissioning satellite constellation missions, which has necessitated tradespace studies to design high-performance, low cost and low risk constellations. An open-source software tool called Tradespace Analysis Tool for Constellations (TAT-C) has been developed at the NASA Goddard Space Flight Center, which aims to facilitate pre-phase A mission studies by generating and optimizing the tradespace of the constellations, involving a multitude of possibly coupled parameters such as orbits, satellites, launchers, ground-stations, and instruments. The performance attributes investigated by TAT-C are instrument data metrics, coverage metrics, cost and risk. While previous research has explored optimization of the constellation satellite orbits using metrics associated with coverage (such as maximizing access duration, maximizing the number of revisits over a region), there is relatively less work on exploring the tradespace of instrument parameters and associated data metrics. Previous research has also used relatively rudimentary data-metrics such as imaged pixel resolutions, range, and angles at which observations are made. This paper describes the instrument data-metrics evaluator of TAT-C which generates more sophisticated data metrics characteristic of the instrument type. The basic concept and the architecture of the evaluator have been developed to accommodate instruments without assuming specifics about the underlying technology. In this paper, we describe the modeling of the two most common types of Earth Observing instruments, namely passive optical sensors and synthetic aperture radars (SARs). The models allow for evaluation of commonly used data-metrics such as the signal to noise ratio, noise equivalent delta temperature, ground-pixel resolutions, dynamic range, noise-equivalent sigma0, etc. The challenges in making the models generic enough for wide usage, while being able to appropriately mimic characteristics of complex real-world instruments, are described using examples such as the Landsat-8 Thermal Infrared Sensor and Operational Land Imager. Lastly, we present results from the instrument data metrics evaluator for three important use cases of mission design with passive-optical sensors and SARs. The first use case explores the tradespace of Sun-Synchronous Orbits from a perspective of data-metrics as opposed to commonly considered coverage metrics. The second use case explores the tradespace of SAR parameters and highlights quantitative trade-offs between instrument parameters influencing the performance, size, and complexity. Such tradespace analysis allows the user to appreciate and consider a fundamental constraint on the SAR antenna size depending on radar frequency. In the last use case, we explore the tradespace of pushbroom vs whiskbroom scanners, and evaluate the conditions under which their performance match.

Several existing three-phase delta voltages’ unbalance factors, including the "true unbalance factor" (the negative sequence voltage unbalance factor) and its complex form, are considered. New geometric criteria of delta voltages’ balance and unbalance, based on the dealing with delta voltages’ triangles of equal perimeters and different areas are offered. All the unbalance factors are shown in their dependences on one particular phase voltage (and also on one particular delta voltage), separately on the magnitude (for the case of a single-phase magnitude unbalance) and on the initial phase angle value (for the case of a single-phase angle unbalance). Also the fragment of a LabVIEW virtual instrument for the assessment of the negative sequence voltage unbalance factor and the new geometric factors is offered.

The long-term trend of pH value and conductivity in precipitation at Baoshan and Pudong in Shanghai during 1993-2018 are reported and the main reasons for the formation of the acid rain at both sites are analyzed. The Yangtze River Delta is one of the severe acid rain areas in China, and the multi-year precipitation pH values at Baoshan from 1993 to 2018 and Pudong from 2008 to 2018 were 5.51 and 4.83, respectively. The precipitation pH trends at Baoshan during 1993-1999, 1999-2009, 2009-2018 were different. The annual precipitation pH variability during 1993-1999 at Baoshan was 0.15 a-1, indicating an increased trend of the pH value. While that during 1999-2009 was- 0.08 a-1, indicating a more severe acid rain pollution trend during this period. But that during 2009-2018 was 0.06 and 0.07 a-1 at Baoshan and Pudong respectively, indicating an upward trend of the pH value at both sites which both consistent with the trend in the Yangtze River Delta. In addition, the acid rain frequency showed the same trend of pH value. The electrical conductivity at two sites declined obviously during 2009-2018. The changes on the regional SO 2 emissions during 1993-2018 were possible reason for the variation characteristics of acid rain. Generally speaking, precipitation at Pudong showed weaker acidity than Baoshan which may because the different pollutants around the sites. The pH value and precipitation were negatively correlated at Baoshan while positive correlated at Pudong. The atmospheric pollutants and precipitation were important effects on the changes of precipitation pH at Baoshan and Pudong.

Logistics industry in China, especially in the Pearl River Delta region, has been affected to different extent as the US unilaterally provokes China-US trade war by imposing tariffs on China and restricting investment starting from August 2017. What have been affected include various logistics factors in the region, e.g. total logistics and transportation, logistics capital investment, logistics labor input, logistics infrastructure investment, logistics technology investment and logistics management service level. The Trade War has made the situation more complicated. Based on the DEA-ANN Model, this article analyzes the logistics data of 9 Delta Cities before and after the Trade War, figures out the development status quo and efficiency of the Delta logistics industry and countermeasures in such a context as Trade War and various factors.

The development of regional integration in the Yangtze River Delta has become part of the national development strategy. The electric power industry in East China is in need of advanced planning to better serve the economic development in the new situation. In this paper, we actively consider how to take the regional integration of Yangtze River Delta as an opportunity to promote the operation and management of local power grid. On the one hand, the construction of energy platforms based on the cooperation of relevant provinces and municipalities is considered. On the other hand, the research and exploration of the ubiquitous power Internet of things are included. Finally, some suggestions for the reform of the electric power system in the Yangtze River Delta region are discussed.

The Irrawaddy River is the largest river in Myanmar with its river delta as the country’s agricultural center. It is of great significance to investigate river channel erosion and ecosystem evolution in such a river delta based on remote sensing. Thus, its river channel erosion/deposition and ecosystem evolution from 1970s to 2011 were analyzed based on Landsat and HJ satellite data through object-oriented supervised classification with the NDVI and NDWI threshold segmentation methods were used. The results show that river channel of Irrawaddy River from Burma Aung to the estuary delta hardly changes in 34 years while area of the estuary shoal is increasing slowly. An overall trend of continuously enlargement of cultivated land and urban land is found in the delta area with a gradually reduced forest land and wet land.

In recent years, with the rapid development of regional economy in the Pearl River Estuary, drastic change in the content and transport patterns of suspended sediment in water bodies, which mainly caused by variations in land use patterns and bank erosion, imposed a profound impact on the development and evolution of the estuary Delta as well as the coastal ecological environment. In this study, we used the measured spectral data to establish inversion algorithm and to inverse suspended sediment based on CASI hyperspectral data, the accuracy of the inversed CASI and MODIS suspended sediment were verified with in-situ measured data. The results show that: 1) Single-band exponential model (SSC=4.5e21.922*Rs(622.486)) can well retrieve the suspended sediment concentration in the experimental sea area, and the average relative error is approximately 11.15%; 2) The suspended sediment content lies between 0.45-12.15 mg/L over the study area, and the main input source is land-based input from the west coast of Huangmao Sea, the ecological impact on the dolphin reserve can be neglected; 3) Combined with MODIS-based remote sensing images of suspended sediment in the Pearl River Estuary, it is found that there is an obvious branching phenomena when the sediment is transported from the Huangmao Sea to the outside of the mouth. The main axis of runoff is transported along the northeast direction of Dajin Island to the southeast direction of Dajin Island in the estuary area, while the coastal current is transported along the northeast direction of Dajin Island to the southwest direction of Dajin Island. As a result, there are low suspended sediment and high transparency sea areas in the north of Dajin Island, which are suitable for aquaculture.

With the rapid development of urbanization, many environmental problems in this stage have seriously threatened human survival and health. The over-exploitation and unreasonable use of water resources increase the uncertainty and risk of future water resources utilization. China, as an important developing country, is in the stage of rapid urbanization. As two important urban agglomerations in China, the Yangtze River Delta and Pearl River Delta deserve to be studied especially in the process of their urbanization.In this paper, GeoSOS-FLUS software was used to simulate the forest loss in the Yangtze River Delta and Pearl River Delta in 2023 during urbanization process, and InVEST model was used to evaluate the water yield in 2013 and 2023 after simulation. It was found that the forest land in both areas decreased and the water yield in Yangtze River Delta decreased considerably. The distribution of forest land in 2023 changed slightly compared with that in 2013, and the total amount increased. In addition, the Yangtze River Delta has increased a lot.

Pakistan is a coastal country (Arabian sea) with 1000 km longer coastline which lies south of the country. Karachi, Ormara, Pasni, and Gwadar are the major seaports. Tropical cyclones are not new for Pakistan. Pakistan has been affected by the several cyclones in few past decades. It is also a region of south Asian monsoon which occurs during June and July and receives heavy and torrential rainfall. Satellite Remote Sensing (SRS) and Geographical Information System (GIS) is used here for identifying the effects of the 2014 cyclone (named as "Nanauk" of category-I) on Indus delta's (wetland) landcovers and the community. Tropical storm Nanauk formed in the west of India on June 10, 2014, and hits the coastal areas on 11 June,2014. The objectives of this study were to; 1) analyze the extent of flooding in Indus delta, 2) to check that after four years of cyclone how many villages/communities returned to their homes and 3) to identify the areas where they migrated at the time of flooding. For 2nd objective, only three tehsils (Ghorabari, Keti Bander and Kharochan) of Thatta district along the three creeks (Khobar, Hajambro, and Turshian) of Indus delta were selected. Landsat-8 satellite images have been used on 10 may(pre-cyclone), 26 may(pre-cyclone), 11 June(during-cyclone) and 27 June(post-cyclone) used to map the flooding extent. Initially, villages were marked using Google earth and Landsat 8 were used to identify the inundated villages. The current status of the inundated villages was checked on google earth which shows that the villages were destroyed, and no boats are standing near the villages as compared to the pre-cyclone images (January and March 2014). The dates of satellite images in Google is not certain, so we requested digital globe for the provision of satellite images to confirm this damage. Digital globe provided images of before cyclones (1st March 2014) which confirms the existence of these villages. Total 27 villages were marked, 18 inundated, 7 Migrated, three relocated and eight returned. The results show that the return ratio of the communities is only 44%, only 16 %return and relocated within the delta and 38% never returned.

A NASA HQ-directed study team led by JPL with partners including APL, MSFC, GSFC, LaRC and Sandia National Laboratory has recently presented an updated mission concept for a Europa Lander that would search for bio-signatures and signs of life in the near-subsurface of the Jovian moon. This paper will describe that mission architecture including science objectives, interplanetary and delivery trajectory, flight system, planetary protection architecture and mission phases. The mission would follow the Europa Multiple-Flyby Mission Clipper planned for launch in 2023, which would provide reconnaissance imagery and other data to the Lander for use in selecting a scientifically compelling site and certifying it for engineering safety. The Europa Lander concept accommodates the Model Payload identified by the Europa Lander Science Definition Team (SDT) and documented in the Europa Lander Study 2016 Report released in February of 2017. Since holding a Mission Concept Review (MCR) in June of 2017, HQ directed the study team to further explore the architectural trade space with a goal of reducing the mission cost. Based on the results of that study, in December of 2017 HQ directed the study team to focus on biosignature science and shift to a Direct-to-Earth communication architecture. The currently envisioned Europa Lander would launch on an SLS Block 1B as early as Fall of 2026 into a $\mathbf{\Delta} \mathbf{V}$ -Earth-Mars-Gravity Assist (AVEMGA) trajectory, arriving in the Jovian system as early as mid-2031. The baseline design of the integrated flight system includes a Carrier Stage, a Deorbit Vehicle composed of a Deorbit Stage consisting of a solid rocket motor (SRM), an MSL-like sky-crane Descent Stage, and a Lander which accommodates the instrument suite. The Lander would be powered by primary batteries over a 20+ day surface mission. The science goals envisioned by the SDT for biosignature science require three samples taken from a depth of 10 cm, a depth chosen to ensure minimal radiation processing of the potential biomarkers. Mission challenges include the large launch mass, unknown terrain topography, surface composition and materials properties, the high radiation environment, and complying with the stringent planetary protection requirements. The mission concept uses a strategy of early risk reduction and overlapping requirements to provide robustness to harsh and uncertain environments. Early risk reduction efforts are aimed at maturing technologies associated with the sampling system, the intelligent landing system, high specific energy batteries, low mass and power motor controllers, and a thermal sterilization system.

Delta Differential One-Way Ranging (ADOR) and Same Beam Interferometry (SBI) are deep space tracking techniques that use two widely separated ground antennas, known as a baseline, to simultaneously track a transmitting spacecraft to measure the time difference between signals arriving at the two stations. Errors are introduced into the delay measurements when the radio waves pass through the solar plasma and the Earth's atmosphere, and also due to clock bias and clock instability of the ground stations. These errors can be eliminated or calibrated by tracking a quasar in the angular vicinity of the spacecraft (ADOR), or by tracking another close-by spacecraft whose trajectory/orbit is accurately known (SBI). Both ADOR and SBI uses this double-differencing of signal arrival time to eliminate the aforementioned error sources, and to generates highly accurate angular measurements with respect to the baseline. The three Deep Space Network (DSN) sites cover three approximately equally-spaced longitudes to provide near-continuous coverage of deep space. Spacecraft occasionally see two DSN sites simultaneously, but never three. Current DSN's ΔDOR and SBI techniques are based on one baseline of two sites. But recent additions of non-DSN deep space antennas and increased cross-support collaborations between space agencies allow spacecraft seeing more than one baselines simultaneously. In this paper, we consider simultaneous SBI of two or more baselines that share one common ground station. We show that under certain condition, precise pointing vector between the common ground station and the spacecraft can be computed using simultaneous ADOR measurements from the two baselines. When there is another spacecraft in the vicinity of the first spacecraft, precise pointing vector of the second spacecraft can be derived from the simultaneous SBI measurements. Also, precise angular distance between the two spacecraft can be computed in real-time. We expect these new data types could enhance ground antenna pointing, and deep space spacecraft traj ectory estimation and orbit determination. This technique can have near-Earth applications. We describe a system concept that detects and locates dead and noncooperative spacecraft in the Geostationary Orbit (GEO). This can be done by making use of an existing GEO satellite with accurately known location as a reference, and/or by placing a dedicated “reference” spacecraft into an eccentric geosynchronous orbit over a region of interest (e.g. above North America). By adjusting the orbit, the “reference” spacecraft can sweep through the sky back-and-forth in the vicinity of the GEO over the region. In this way, the reference spacecraft can be close to any “static” GEO targets along its path. Using the multi-static radar approach, the ground transmitting radar illuminates both the reference and target spacecraft, and the ground receiving radars measure the different time-delays of signal arrival. Applying a variant of the aforementioned simultaneous SBI scheme, the time-delay measurements can be used to compute the precise relative position of the target spacecraft with respect to the reference spacecraft, whose position can be accurately estimated using the weak Global Positioning Satellite (GPS) signals.

This paper describes the results of a study to find possible Near Earth Asteroids (NEA) capable of being captured using upcoming rocketry for the purposes of space-based mining, combining reusable rockets such as SpaceX's Big Falcon Rocket (i.e. BFR) and refueling capabilities. This work introduces a relatively low-cost option with higher Delta V, $\triangle V$ , compared to non-reusable rockets, and an opportunity for NASA's Lunar Orbital Platform-Gateway (LOP-G) for synergy with services, science, and technologies. In an effort to maximize the number of viable missions, the study focused on choosing a refueling orbit near LOP-G; thus, the Earth-Moon Lagrange points L1 and L2 were selected as possible choices for this paper. The resulting simulations of a Cislunar infrastructure orbiting in Lagrange points highlight differences in orbital options. Indeed, the optimal option is balanced between a Near Rectilinear Halo Orbit (NRHO) in L1 and a NRHO in L2. The decision for optimal positioning of any Gateway Station is dependent on the type of mission allocated to the Cislunar station. However, both options seem promising, not only for asteroid extraction and mining but also for crewed and cargo missions. In a worst case scenario, an operation of 3 decades starting in 2030 retrieving 33 asteroids, or 1.1 per year, comprising up to 2,581 tons in minerals. The work culminated in developing a data mining online tool that searches the entire Near Earth Asteroids (NEA) close approach database from JPL and the small body database from NASA. Using a fleet of 10 BFRs over 30 years may provide a higher long-term success for a business case than any other investment on Earth.

Delta Differential One-way Ranging (DDOR) is a Very Long Baseline Interferometry (VLBI)-based technique for navigation of interplanetary spacecrafts. ISRO’s Mars Orbiter Mission (MOM) launched in November 2013, and orbiting Mars ever-since September 2014, uses this technique along with Ranging and Doppler-based navigation techniques for accurate Spacecraft Orbit Determination.

As the main power source over Yangtze River Delta, coal combustion from power plant will produce a large number of pollutants, which impacts the regional air quality. The characteristics of emissions from power plant in winter over Yangtze River Delta are firstly analyzed, and characteristics of air pollutants simulated based on WRF-Chem model in January 2015 are then discussed. The results showed: (1) the main air pollutants from power plant over Yangtze River delta are SO 2 , NO2 and PM2.5, and the annual emissions are 826.8Gg, 1475.6Gg and 137.3Gg, respectively, accounting for 34%, 38% and 14% of total emissions, respectively; (2) the simulation shows that the area with high concentration of SO 2 , NO 2 and PM2.5are corresponding to the high emissions from power plant, indicating distinct contribution to air pollution from power plant in winter. (3) Comparisons between clean and polluted conditions show that low temperature, wind speed and boundary layer height found over the region in winter are favorable to pollutant accumulation, leading to heavy pollution events.

Automated production systems (aPS) operate for a long time with continuous and incremental changes. However, the models for aPS have not been maintained along with these system changes or, even, have not been properly generated. Even though the regression verification technique reduces the effort of applying formal verification on the automation system evolution, there still remains what should be provided in a formal form for the verification: delta, which is the difference of the two versions of the software. In this paper, we propose a method for generating a formal model from preexisting software in IEC 61131–3 Sequential Function Chart language. Based on this, the developer is able to achieve delta description by revising it to reflect the change request and this formal description of delta could facilitate verifying delta formally.