LIVIVO - Search results -

Search results

Result 1 - 10 of total 47

Search options

Article ; Online: Assessment of Effective Roughness Parameters for Simulating Sentinel-1A Observation and Retrieving Soil Moisture over Sparsely Vegetated Field

Xiaojing Wu

Remote Sensing, Vol 14, Iss 6020, p

2022 Volume 6020

Abstract: The variability of surface roughness may lead to relatively large dynamic of backscatter coefficient observed by the synthetic aperture radar (SAR), which complicates the soil moisture (SM) retrieval process based on active remote sensing. The effective ... ...

Abstract	The variability of surface roughness may lead to relatively large dynamic of backscatter coefficient observed by the synthetic aperture radar (SAR), which complicates the soil moisture (SM) retrieval process based on active remote sensing. The effective roughness parameters are commonly used for parameterizing the soil scattering models, the values of which are often assumed to be constant during different study periods for the same site. This paper investigates the reasonableness of this hypothesis from the perspective of backscatter coefficient simulation and SM retrieval using high resolution SAR data. Three years of Sentinel-1A data from 2016 to 2018 were collected over a sparsely vegetated field within the REMEDHUS SM monitoring network. The advanced integral equation model (AIEM) and Dobson dielectric mixing model were combined for optimizing the effective roughness parameters, as well as simulating the backscatter coefficient and retrieving the SM. The effective roughness parameters were optimized at different temporal periods, such as 2016, 2017, 2018, 2016 + 2017, 2017 + 2018, and 2016 + 2017 + 2018, to analyze their temporal dynamics. It was found that: (1) the effective roughness parameters optimized at different temporal periods are very close to each other; (2) the simulated backscatter from AIEM is consistent with Sentinel-1A observation with root mean square errors (RMSEs) between 1.133 and 1.163 dB and correlation coefficient ® value equals to 0.616; (3) the seasonal dynamics ofin situ SM is well-captured by the retrieved SM with R values floating at 0.685 and RMSEs ranging from 0.049 to 0.052 m 3 /m 3 and (4) inverse of the AIEM with the implementation of effective roughness parameters achieves better performance for SM retrieval than the change detection method. These findings demonstrate that the assumption on the constant effective roughness parameters during the study period of at least three years is reasonable.
Keywords	SM retrieval ; Sentinel-1 ; AIEM ; effective roughness ; change detection ; Science ; Q
Subject code	550
Language	English
Publishing date	2022-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Identification of Co-Clusters with Coherent Trends in Geo-Referenced Time Series

Xiaojing Wu

ISPRS International Journal of Geo-Information, Vol 11, Iss 134, p

2022 Volume 134

Abstract: Several studies have worked on co-clustering analysis of spatio-temporal data. However, most of them search for co-clusters with similar values and are unable to identify co-clusters with coherent trends, defined as exhibiting similar tendencies in the ... ...

Abstract	Several studies have worked on co-clustering analysis of spatio-temporal data. However, most of them search for co-clusters with similar values and are unable to identify co-clusters with coherent trends, defined as exhibiting similar tendencies in the attributes. In this study, we present the Bregman co-clustering algorithm with minimum sum-squared residue (BCC_MSSR), which uses the residue to quantify coherent trends and enables the identification of co-clusters with coherent trends in geo-referenced time series. Dutch monthly temperatures over 20 years at 28 stations were used as the case study dataset. Station-clusters, month-clusters, and co-clusters in the BCC_MSSR results were showed and compared with co-clusters of similar values. A total of 112 co-clusters with different temperature variations were identified in the Results, and 16 representative co-clusters were illustrated, and seven types of coherent temperature trends were summarized: (1) increasing; (2) decreasing; (3) first increasing and then decreasing; (4) first decreasing and then increasing; (5) first increasing, then decreasing, and finally increasing; (6) first decreasing, then increasing, and finally decreasing; and (7) first decreasing, then increasing, decreasing, and finally increasing. Comparisons with co-clusters of similar values show that BCC_MSSR explored coherent spatio-temporal patterns in regions and certain time periods. However, the selection of the suitable co-clustering methods depends on the objective of specific tasks.
Keywords	co-clustering ; coherent trends ; The Netherlands ; temperature series ; data mining ; Geography (General) ; G1-922
Subject code	540 ; 550
Language	English
Publishing date	2022-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Implementation of Two-Stream Emission Model for L-Band Retrievals on the Tibetan Plateau

Xiaojing Wu

Remote Sensing, Vol 14, Iss 494, p

2022 Volume 494

Abstract: This study assesses the suitability of the two-stream microwave emission model in simulating brightness temperature ( T B p ) and retrieving liquid water content ( θ liq ) at L-band in combination with the four-phase dielectric model for both thawed and ... ...

Abstract	This study assesses the suitability of the two-stream microwave emission model in simulating brightness temperature ( T B p ) and retrieving liquid water content ( θ liq ) at L-band in combination with the four-phase dielectric model for both thawed and frozen soil. Both single (SCA) and double (DCA) channel algorithms are adopted using both ground-based ELBARA-III and spaceborne SMAP measurements conducted in a Tibetan grassland site. The ELBARA-III measured T B p are smaller than the SMAP measurements in the warm season due to a lower value of average θ liq presented within the ELBARA-III footprint. The two-stream emission model configured with SMAP vegetation and surface roughness parameterization underestimates both ELBARA-III and SMAP measured T B p at horizontal polarization in the cold season, and overestimates the vertical polarized measurements ( T B V ) in the warm season. Implementation of a new surface roughness and vegetation parameterization resolves above deficiency, and the simulations capture better large-scale SMAP measurements in comparison to these performed for the ELBARA-III footprint. The dynamics of in situ θ liq are better reproduced by retrievals using the SCA based on T B V measurements (SCA-V), whereby the SCA-V retrievals using the SMAP ascending overpass measurements shows the best results with an unbiased root-mean-square error (ubRMSE) of 0.035 m 3 m −3 that outperforms the SMAP mission specification.
Keywords	Soil Moisture Active Passive (SMAP) ; L-band microwave radiometry ; thawed and frozen soil conditions ; liquid water content ; grassland ; Tibetan Plateau ; Science ; Q
Subject code	333 ; 290
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Recent Progress on Modeling Land Emission and Retrieving Soil Moisture on the Tibetan Plateau Based on L-Band Passive Microwave Remote Sensing

Xiaojing Wu / Jun Wen

Remote Sensing, Vol 14, Iss 4191, p

2022 Volume 4191

Abstract: L-band passive microwave remote sensing (RS) is an important tool for monitoring global soil moisture (SM) and freeze/thaw state. In recent years, progress has been made in its in-depth application and development in the Tibetan Plateau (TP) which has a ... ...

Abstract	L-band passive microwave remote sensing (RS) is an important tool for monitoring global soil moisture (SM) and freeze/thaw state. In recent years, progress has been made in its in-depth application and development in the Tibetan Plateau (TP) which has a complex natural environment. This paper systematically reviews and summarizes the research progress and the main applications of L-band passive microwave RS observations and associated SM retrievals on the TP. The progress of observing and simulating L-band emission based on ground-, aircraft-based and spaceborne platforms, developing regional-scale SM observation networks, as well as validating satellite-based SM products and developing SM retrieval algorithms are reviewed. On this basis, current problems of L-band emission simulation and SM retrieval on the TP are outlined, such as the fact that current evaluations of SM products are limited to a short-term period, and evaluation and improvement of the forward land emission model and SM retrieval algorithm are limited to the site or grid scale. Accordingly, relevant suggestions and prospects for addressing the abovementioned existing problems are finally put forward. For future work, we suggest (i) sorting out the in situ observations and conducting long-term trend evaluation and analysis of current L-band SM products, (ii) extending current progress made at the site/grid scale to improve the L-band emission simulation and SM retrieval algorithms and products for both frozen and thawed ground at the plateau scale, and (iii) enhancing the application of L-band satellite-based SM products on the TP by implementing methods such as data assimilation to improve the understanding of plateau-scale water cycle and energy balance.
Keywords	L-band ; passive microwave RS ; land emission model ; SM retrieval ; TP ; Science ; Q
Subject code	530
Language	English
Publishing date	2022-08-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Cultural landscape perception of the Chinese traditional settlement

Jingjing Zhou / Shanshan Wu / Xiaojing Wu / Xiumin Xia

PLoS ONE, Vol 18, Iss

Based on tourists’ online comments

2023 Volume 4

Abstract: The cultural landscape in traditional settlements is an important historical and cultural resource created by human beings in the process of historical evolution, and is an important resource for the development of traditional settlement tourism. This ... ...

Abstract	The cultural landscape in traditional settlements is an important historical and cultural resource created by human beings in the process of historical evolution, and is an important resource for the development of traditional settlement tourism. This paper selected 21 representative traditional settlements for research using online comments from tourists as data and content analytical methods including high-frequency vocabulary, semantic networks and emotional attitudes to explore the public perspective on the connotations of cultural landscape features in traditional settlements. There are four major findings, showing first that the cultural landscape of traditional settlements contains three core elements. Second, the semantic network relationships of the core elements show a significant central–edge tendency; and third, the emotional perception of cultural landscapes in traditional settlements is generally positive, and there is no significant difference emotionally between each core element. Last, the public’s perception of the cultural connotations of the landscape is seriously insufficient. Based on the research results, planning suggestions and countermeasures for the conservation and utilization of cultural landscapes in traditional settlements are proposed.
Keywords	Medicine ; R ; Science ; Q
Subject code	930 ; 710
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Cultural landscape perception of the Chinese traditional settlement

Jingjing Zhou / Shanshan Wu / Xiaojing Wu / Xiumin Xia

PLoS ONE, Vol 18, Iss 4, p e

Based on tourists' online comments.

2023 Volume 0283335

Abstract	The cultural landscape in traditional settlements is an important historical and cultural resource created by human beings in the process of historical evolution, and is an important resource for the development of traditional settlement tourism. This paper selected 21 representative traditional settlements for research using online comments from tourists as data and content analytical methods including high-frequency vocabulary, semantic networks and emotional attitudes to explore the public perspective on the connotations of cultural landscape features in traditional settlements. There are four major findings, showing first that the cultural landscape of traditional settlements contains three core elements. Second, the semantic network relationships of the core elements show a significant central-edge tendency; and third, the emotional perception of cultural landscapes in traditional settlements is generally positive, and there is no significant difference emotionally between each core element. Last, the public's perception of the cultural connotations of the landscape is seriously insufficient. Based on the research results, planning suggestions and countermeasures for the conservation and utilization of cultural landscapes in traditional settlements are proposed.
Keywords	Medicine ; R ; Science ; Q
Subject code	930 ; 710
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Tri-Clustering Based Exploration of Temporal Resolution Impacts on Spatio-Temporal Clusters in Geo-Referenced Time Series

Xiaojing Wu / Donghai Zheng

ISPRS International Journal of Geo-Information, Vol 9, Iss 210, p

2020 Volume 210

Abstract: Unprecedented amounts of spatio-temporal data instigates an urgent need for patterns exploration in it. Clustering analysis is useful in extracting patterns from big data by grouping similar data elements into clusters. Compared with one-way clustering ... ...

Abstract	Unprecedented amounts of spatio-temporal data instigates an urgent need for patterns exploration in it. Clustering analysis is useful in extracting patterns from big data by grouping similar data elements into clusters. Compared with one-way clustering and co-clustering methods, tri-clustering methods are more capable of exploring complex patterns. However, the explored patterns or clusters could be different due to varying temporal resolutions of input data. This study presents a tri-clustering based method to explore the impacts of different temporal resolutions on spatio-temporal clusters identified in geo-referenced time series (GTS), one type of spatio-temporal data. Dutch daily temperature data at 28 stations over 20 years was used to illustrate this study. The temperature data at daily, monthly, and yearly resolutions were subjected to the Bregman cube average tri-clustering algorithm with I-divergence (BCAT_I) to detect spatio-temporal clusters, which were then compared in terms of patterns exhibited, compositions, and changed elements. Results confirm the temporal resolution impacts on the spatio-temporal clusters identified in the Dutch temperature data: most compositions of clusters are varying when changing the temporal resolutions of input data in the GTS. Nevertheless, there is almost no change of elements in certain clusters (12 stations in the northeast of the country; years 1996, 2010) at all temporal resolutions, suggesting them as the “true” clusters in the case study dataset.
Keywords	tri-clustering ; spatio-temporal clusters ; geo-referenced time series ; Modifiable Temporal Unit Problem (MTUP) ; Dutch temperature ; Geography (General) ; G1-922
Language	English
Publishing date	2020-03-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: The assessment of mesenchymal stem cells therapy in acute on chronic liver failure and chronic liver disease

Yuwei Liu / Yutong Dong / Xiaojing Wu / Xiaotong Xu / Junqi Niu

Stem Cell Research & Therapy, Vol 13, Iss 1, Pp 1-

a systematic review and meta-analysis of randomized controlled clinical trials

2022 Volume 16

Abstract: Abstract Background Mesenchymal stem cells (MSCs) therapy is showing potential therapeutic effects on liver function improvement in patients with chronic liver disease; however, the consensus on efficacy and safety of MSCs has not been reached. Methods ... ...

Abstract	Abstract Background Mesenchymal stem cells (MSCs) therapy is showing potential therapeutic effects on liver function improvement in patients with chronic liver disease; however, the consensus on efficacy and safety of MSCs has not been reached. Methods We performed this systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of MSCs therapy for patients with chronic liver disease. A detailed search of the Cochrane Library, MEDLINE, Web of Science, and EMBASE databases was conducted to find studies published prior to September 15, 2021. The outcome measures were survival rate, model of end-stage liver disease (MELD) score, albumin, total bilirubin, coagulation function, and aminotransferase. Results A literature search resulted in 892 citations. Of these, 12 studies met the inclusion criteria. It was found that compared with conventional treatment, MSCs therapy was associated with improved liver function including the MELD score, albumin levels, and coagulation function. However, it had no obvious beneficial effects on survival rate and aminotransferase levels. Subgroup analyses indicated that MSCs therapy had therapeutic effects on patients with both acute on chronic liver failure (ACLF) and cirrhosis. BM-MSCs and UC-MSCs treatment had similar efficacy to improve liver function. The effectiveness varied slightly between the peripheral intravenous injection and hepatic arterial injection. Five studies reported that the only adverse event of the MSCs therapy was fever, and no serious adverse events and side effects were reported. Analysis on clinical symptoms showed that encephalopathy and gastrointestinal hemorrhage events were reduced after MSCs therapy. Conclusions In conclusion, this study suggested that MSCs therapy could be a potential therapeutic alternative for patients with chronic liver disease in clinical practice.
Keywords	Mesenchymal stem cells ; Liver disease ; Efficacy ; Safety ; Meta-analysis ; Medicine (General) ; R5-920 ; Biochemistry ; QD415-436
Subject code	610
Language	English
Publishing date	2022-05-01T00:00:00Z
Publisher	BMC
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Integration of targeted sequencing and pseudo-tetraploid genotyping into clinically assisted decision support for β-thalassemia invasive prenatal diagnosis.

Wenguang Jia / Jiying Shi / Hengying Zhu / Xiaojing Wu / Yayun Ling / Ping Chen

PLoS ONE, Vol 18, Iss 4, p e

2023 Volume 0283668

Abstract: Background The high prevalence of β-thalassemia indicates the severe medical burden in Guangxi province in China. Millions of thousands of prenatal women with healthy or thalassemia-carrying fetuses received an unnecessary prenatal diagnosis. We designed ...

Abstract	Background The high prevalence of β-thalassemia indicates the severe medical burden in Guangxi province in China. Millions of thousands of prenatal women with healthy or thalassemia-carrying fetuses received an unnecessary prenatal diagnosis. We designed a prospective single-center proof-of-concept study to evaluate the utility of a noninvasive prenatal screening method in the stratification of beta-thalassemia patients before invasive procedures. Methods Next-generation and optimized pseudo-tetraploid genotyping-based methods were utilized in preceding invasive diagnosis stratification to predict the mater-fetus genotype combinations in cell-free DNA, which is from maternal peripheral blood. Populational linkage disequilibrium information with additional neighboring loci to infer the possible fetal genotype. The concordance of the pseudo-tetraploid genotyping with the gold standard invasive molecular diagnosis was used to evaluate the effectiveness of this method. Results 127 β-thalassemia carrier parents were consecutively recruited. The total genotype concordance rate is 95.71%. The Kappa value was 0.8248 for genotype combinations and 0.9118 for individual alleles. Conclusion This study offers a new approach to picking out the health or carrier fetus before invasive procedures. It provides valuable novel insight into patient stratification management on β-thalassemia prenatal diagnosis.
Keywords	Medicine ; R ; Science ; Q
Subject code	610
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Research on UAV route planning based on adaptive multi heuristic ant colony algorithm

Yanan YIN / Ran ZHEN / Xiaojing WU / Chunyue ZHANG / Xueli WU

Journal of Hebei University of Science and Technology, Vol 42, Iss 1, Pp 38-

2021 Volume 47

Abstract: In order to solve the problem that ant colony algorithm is easy to fall into local optimum in UAV route planning, an improved ant colony algorithm was proposed. The upper and lower limits of pheromone volatilization factor and pheromone were set to ... ...

Abstract	In order to solve the problem that ant colony algorithm is easy to fall into local optimum in UAV route planning, an improved ant colony algorithm was proposed. The upper and lower limits of pheromone volatilization factor and pheromone were set to prevent ants from falling into local optimum because pheromone on short path was too high or pheromone on long path was too low. At the same time, under the influence of multiple heuristic factors, the overall length of the path was taken as an adaptive heuristic function factor to determine the state transition probability. When the path length was large, the adaptive heuristic function factor was small, which reduced the probability of choosing the path by the ant colony. The experimental results show that the improved algorithm reduces the path length by 6.4% and the variance of the optimal path length by 85.78%, which increases the consideration of environmental integrity, shortens the path length, reduces the number of iterations, and jumps out of the local optimum. In the case of increasing environmental complexity, the algorithm can effectively choose a better path and provide a theoretical basis for UAV route planning after introducing the adaptive heuristic function factor.
Keywords	basic science and technology of aeronautics and astronautics other disciplines ; uav ; ant colony algorithm ; route planning ; heuristic factors ; Technology ; T
Subject code	000
Language	Chinese
Publishing date	2021-02-01T00:00:00Z
Publisher	Hebei University of Science and Technology
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED