Bit-depth enhancement plays a pivotal role in bridging legacy low bit-depth images with high dynamic range displays by high bit-depth image reconstruction. While existing methods achieved considerable performance, they are still subject to the fundamental limitation of the task’s ill-posed nature. In this paper, we propose a novel Invertible Bit-depth Enhancement Network (IBEN) that explicitly establishes bidirectional mappings between bit-depth degradation and bit-depth enhancement through invertible neural modeling. Our method introduces two key innovations: (1) invertible bit-depth split block and affine coupling block that decouples bit-plane information dropping into learnable latent variables while maintaining strict invertiblity, and (2) bidirectional constrained learning paradigm combining degradation consistency loss, latent distribution alignment, and enhancement reconstruction loss to ensure cycle-consistent optimization. Extensive experiments demonstrate superior performance compared with existing methods both quantitatively and qualitatively.

With the rapid development of Low Earth Orbit constellations, the importance of accurately estimating thermospheric mass density is steadily increasing. Current empirical models still exhibit unavoidable biases in estimating thermospheric mass density. In this paper, we propose a novel two-step empirical model calibration enhancement method. The enhancement coefficients are constructed by the second-order spherical harmonic function and the machine learning method. The daily in situ mass density observations collected by the SWARM-C and GRACE-A satellites between 2015 and 2017 are used to generate coefficients and test the model. The two-step enhancement method performs well under various conditions, including different satellites, altitudes, and space weather scenarios. During storm periods, using satellite observations as the references, the enhanced MSIS 2.1 model can achieve estimation error reduction of over 15%. During long-term testing in 2015, 2016, and 2017, the average RMSEs of the enhanced thermospheric mass density decreased by 23.06%, 20.33%, and 30.95%, respectively.

Neutral thermospheric density is a crucial parameter for orbital tracking and upper atmosphere research. Here, we present a method to monitor global neutral thermospheric density testing simulations in various space environments with various satellite configurations and altitudes. The simulation results at 1 degrees x 1 degrees pixel resolution show that (1) within the range of 300-600 km orbital altitudes, the monitoring accuracy improves with the increase of the number of satellites, but this gain is significantly attenuated when the number of satellites increases to approximately 1,000; (2) the monitoring accuracy decreases with the increase of the altitude; and (3) the method presented in this study exhibits robustness under different space weather conditions. Furthermore, a differentiated satellite usage strategy (High Tightness and Low Looseness, HTLL) is developed to reduce the number of satellites used. Preliminary results indicate that the use of the HTLL method can reduce the number of satellites used from 2,592 to 1,044, whereas the maximum average relative deviation (ARD) does not exceed 1 %. The methods presented in this study have potential for future applications in the development of thermo (c) 2024 COSPAR. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

To provide backup and supplementation for the Global Navigation Satellite System (GNSS), Doppler shift from Low Earth Orbit (LEO) satellites can be used as signals of opportunity to provide positioning, navigation, and timing service. In this contribution, we first investigate the model and performance of instantaneous velocity determination and positioning with LEO satellites. Given a LEO constellation with 288 satellites, we simulate Doppler shift observations at nine multi-GNSS experiment stations. Owing to the lower orbit, the performance of LEO velocity determination is much more sensitive to the initial receiver position error than that of GNSS. Statistical results show that with the initial receiver position error increased from 0.1 to 10 m, the Root Mean Square Errors (RMSEs) increase from 0.73 to 2.65 cm/s, 0.68 to 2.96 cm/s, and 1.67 to 4.15 cm/s in the east, north, and up directions, respectively. The performances with GPS are compared with GPS + LEO, and it is found that LEO Doppler shift observations contribute to GPS velocity determination. As for LEO Doppler positioning, even if more than 30 visible LEO satellites are available, the position dilution of precision values can reach several hundreds. Assuming that the error of LEO Doppler measurements is 0.01 m/s, the instantaneous Doppler positioning accuracy can achieve about a few meters, which is comparable to that of GNSS pseudorange positioning. A constant velocity model is adopted for state transition. Static LEO Doppler positioning results show that an accuracy at centimeter to decimeter level can be achieved after solution convergence. For a static simulated kinematic positioning test, the RMSEs range from a few decimeters to several meters in different regions by giving different constraints. For a dynamic positioning test, the RMSEs are about 2–3 m in high latitude region.

Frequent object counting at a specific location (FOC@Loc) is becoming a newly emerging but highly demanded task since the evolution of human activities can provide crucial statistics for social and economic development. Due to the unique requirement of both high temporal frequency for frequent observations and high spatial resolution for object counting, this article aims to propose a novel framework for FOC@Loc to take advantage of both high definitions of high-resolution (HR) image and continuous low-cost low-resolution (LR) image at the same location. To compensate for the low ground sample distance (GSD) in LR images, some prior knowledge about the fixed location is extracted from HR images, including (1) the short-term spatial consistency: provide exact feature-wise and pixel-wise guidance from HR image to the LR image on the same date, learning to predict vehicle area for each LR image; (2) the long-term location consistency: provide the prior parking density of the study location from the sparse HR image sequence, turning the vehicle area into the counting number of each LR image. The final results indicate that this new method obtains highly consistent counting results with the manual annotations, proofing that the HR image guidance information can promote the utilization of LR images for object counting and further analysis. The proposed dataset and methodology have the potential to boost the applications of extensive and inexpensive LR satellite images.

Abstract The use of low earth orbit (LEO) satellites to enhance the performance of global navigation satellite system navigation and positioning services has become a popular research topic. In this study, NSGA‐III optimisation algorithm was used to design two hybrid configurations of 177 and 186 LEO constellations for enhancing the BeiDou Satellite Navigation System (BDS). Under the enhanced effect of optimisation constellation, the global average geometric dilution of precision (GDOP) of BDS was reduced to 0.8 ± 0.1, and the maximum GDOP was reduced from 2.4 to less than 1.1 (54.2% reduction). In order to verify the contribution of the two constellations to the convergence time and positioning accuracy of BDS precise point positioning (PPP), a LEO enhanced BDS PPP simulation experiment was carried out using International GNSS Service data from five stations. The results show that after 10 min of static positioning, both LEO constellations improved the positioning accuracy of BDS from the decimetre level to less than 5 cm. The maximum improvement for 177 and 186 LEO was 95.0% and 96.9%, respectively. Additionally, the convergence time for 177 and 186 LEO reduced to less than 3.5 and 3 min, and the maximum improvement was 93.5% and 95.2%, respectively. Overall, both constellations can improve the positioning accuracy and convergence time of BDS PPP.

To minimize the unexpected seismic damage,it is significant to evaluate the potantial seismic risk in the high probabilisitic seismic hazard zones and take effective precautionary measures.This paper aims to evaluate the risk of heavy metal non-point source pollution caused by seismic-led industrial building collapse.It is based on the seismic hazard of 10-percent probability of exceedance in 50 years,and the minimum value of the water quality standard in Sichuan,China.The method of Soil Conservation Service (SCS) curve number (CN) was used to compute the daily runoff depth,and to estimate the potential risk state of non-point source heavy metal pollution combined with the seismic damage index and population index.The results indicate:(1) eleven sub-basins are under the potential risk of seismic-led non-point source heavy metal pollution;(2) Compared to other heavy metal pollutants,more sub-basins are under the risk of Cr6+ pollution,and are mainly distributed in the northeast,central and south central of Sichuan province,whereas high risk subbasins of other heavy metal pollutants are most located in the south central areas of Sichuan province;(3) considering the population index,the high risk areas of Cr6+ pollution are mainly in the southeast of sub-basins Wl and W2,while those subjected to pollution of other heavy metals are mostly in the north of sub-basin W4.

The secondary water disasters of earthquake,caused by breaking out of the reservoirs,dams,dikes,irrigation canal and other basic and important water infrastruc-tures,will bring heavy water disasters to human lives.This paper aims to analyze the char-acterisics of the types and their damages of the secondary drinking water disasters caused by seismic hazard,and discuss on the potential hazard that may bring to the drinking water in affected zones.Measures of prevention and protection of the drinking water from seismic hazard were finally proposed.

Estimation of economic loss is significant for reconstructions after earth-quake.This paper aims to compare qualitatively the classical model HAZUS-MH,which is built up in US and applied as the basic model of developing seismic loss estimation models in many countries,with the one that are generally applied in China.The comparison results can be applied as an important reference to decision makers.

The graduate enrollment is influenced by the current national policy, the social needs, and the social economic status and so on. The change of the enrollment number shows the nonlinearity and the complexity. In order to have better grasp of the enrollment scale and to realize the rational allocation of educational resources, we propose a Multi-Experiential Particle Swarm Optimization (MEPSO) algorithm. The algorithm is combined with the Error Back Propagation (BP) algorithm to establish a new neural network that is called the MEPSO-BP neural network. Then we present the simulation numerical studies based on several typical algorithms. The results show the MEPSO-BP algorithm improves the convergence speed and the predictive accuracy, and it can be regarded as a new method for the graduate enrollment prediction.

The objective of this paper is to evaluate seismic-led point source and non-point source water pollution, under the seismic hazard of 10 % probability of exceedance in 50 years, and with the minimum value of the water quality standard in Sichuan, China. The soil conservation service curve number method of calculating the runoff depth in the single rainfall event combined with the seismic damage index were applied to estimate the potential degree of non-point source water pollution. To estimate the potential impact of point source water pollution, a comprehensive water pollution evaluation framework is constructed using a combination of Water Quality Index and Seismic Damage Index methods. The four key findings of this paper are: (1) The water catchment that has the highest factory concentration does not have the highest risk of non-point source water contamination induced by the outbreak of potential earthquake. (2) The water catchment that has the highest numbers of cumulative water pollutants types are typically located in the south western parts of Sichuan where the main river basins in the regions flow through. (3) The most common pollutants in sample factories studied is COD and NH3-N which are found in all catchments. The least common pollutant is pathogen-found present in W1 catchment which has the best rating in the water quality index. (4) Using water quality index as a standardization parameter, parallel comparisons is made among the 16 water catchments. Only catchment W1 reaches level II water quality status which has the rating of moderately polluted in events of earthquake induced water contamination. All other areas suffer from severe water contamination with multiple pollution sources. The results from the data model are significant to urban planning commissions and businesses to strategically choose their factory locations in order to minimize potential hazardous impact during the outbreak of earthquake.

Based on remote sensing and GIS technology, a method for measuring the land urbanization level using DMSP/OLS nighttime light data was proposed, and then the land urbanization level in Bohai Rim from 1992 to 2010 was measured. The conclusions are as follows.(1) The urban land in Bohai Rim from 1992 to 2010 was extracted from DMSP/OLS nighttime light data with an average overall accuracy of 88.11% and an average Kappa of 0.61. It can well reflect the real status of regional urban land change with a certain level of reliability.(2) In general, the land urbanization level in Bohai Rim increased rapidly from 0.82% in 1992 to 3.20% in 2010, with an average annual growth rate of 7.80%.(3) The regional differences of land urbanization levels among urban agglomerations, cities with different distances to the coastline, between coastal cities and other cities, were significant and exhibited a growing trend from 1992 to 2010.(4)The regions with high level of land urbanization show a spatial character of locating close to the coast. This research can contribute to quick and effective measurement of regional land urbanization level, and provide decision-making reference for the optimization of regional urban patterns and the construction of the new-type urbanization.

Publicizing land information query is the increasing demand of the public for land information and open governmental affairs.This article begins with the analysis of our existing public land information query system.Firstly,it studies the principals in the design of land registration information public query system.Secondly,it analyzes and classifies the system users,thus finds out their functional requirements.Then it classifies the functional modules of land information public query system.In the end,the authors make an empirical study on the result of this article with Ningbo City land information enquiry system as a case study,hoping to offer some help for the development and research of China land information public query system.

Estimation of the seismic risk of schools in developing countries is an important but challenging task. In this paper, we report an attempt to estimate the damage and losses of primary schools during the Mw7.9 Wenchuan earthquake that ruptured on 12 May 2008 using SELENA (SEismic Loss EstimatioN from a logic tree Approach). In this study, the seismic hazard was assessed with the probabilistic analysis procedures available in SELENA. The capacity spectrum method (CSM) was applied to determine the vulnerability function, which is a basic input for estimating building damages and losses. The HAZUS methodology was used for estimating human losses. This paper reports preliminary results about the seismic risk of primary schools in some affected areas of the Wenchuan earthquake. In addition, it presents some findings about the usefulness of SELENA for estimating damages and losses of schools using data from a developing country like China.

Eutrophication, which may influence the sustainability of the natural environment, is one of the notable water environment problems. This paper aims to estimate the water eutrophication of Moshui Lake in Hanyang District of Wuhan in central China as a case study with a Fuzzy Comprehensive-Quantifying Assessment (FCQA) method. The evaluation of changes of the water trophic state is based on the monitoring data of trophic indictors, TP and TN, between 2001 and 2010. The Scoring Method was applied to test the feasibility of using the FCQA method in the estimation of the water eutrophication state. Then, the Dynamic Gray Filling Model (GM (1, 1) model) was used to forecast trophic states of Moshui Lake between 2010 and 2016, while the forecasted value of 2010 was compared with that value calculated by the real monitoring data. The results indicated that the FCQA method had the advantages such as comparability and accuracy and is available for water eutrophication assessment. The average precision of the forecasted results by the Dynamic GM (1,1) is 95.91%. The improvement of the water trophic state of Moshui Lake from 2001 - 2016 can be defined in three stages: (1) Heavy eutropher in 2001-2005, (2) Moderate eutropher in 20062015, and (3) Light eutropher in 2016. The alleviation of the water trophic situation is mainly due to the human activities of environmental rescue. However, the still existing trophic problems in Moshui Lake indicate the importance of further environmental rescue work and people's awareness of keeping a sustainable water environment in the future.

<正>心理素质是指人在先天遗传基础上发展和培养的良好心理品质。它包括智力因素(认知、运筹、决策)、非智力因素(需要、动机、情感)和复合因素(意志、气质、审美、社交、道德等)。其中智力因素是人类认识自然的本质及其规律的一般能

在档案整理的过程中,立卷人员常常会碰到这样的一些文件:它们或在破损,或纸质很差,或幅面过小,或在应装订处写有字迹.对于这些"不合格"的文件,如果直接装订,往往会造成案卷中的文件脱页或将有用信息装进卷脊中,降低案卷的质量,不利于档案的保存和作用.