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Article ; Online: Detecting and Visualizing Observation Hot-Spots in Massive Volunteer-Contributed Geographic Data across Spatial Scales Using GPU-Accelerated Kernel Density Estimation

Guiming Zhang

ISPRS International Journal of Geo-Information, Vol 11, Iss 55, p

2022 Volume 55

Abstract: Volunteer-contributed geographic data (VGI) is an important source of geospatial big data that support research and applications. A major concern on VGI data quality is that the underlying observation processes are inherently biased. Detecting ... ...

Abstract	Volunteer-contributed geographic data (VGI) is an important source of geospatial big data that support research and applications. A major concern on VGI data quality is that the underlying observation processes are inherently biased. Detecting observation hot-spots thus helps better understand the bias. Enabled by the parallel kernel density estimation (KDE) computational tool that can run on multiple GPUs (graphics processing units), this study conducted point pattern analyses on tens of millions of iNaturalist observations to detect and visualize volunteers’ observation hot-spots across spatial scales. It was achieved by setting varying KDE bandwidths in accordance with the spatial scales at which hot-spots are to be detected. The succession of estimated density surfaces were then rendered at a sequence of map scales for visual detection of hot-spots. This study offers an effective geovisualization scheme for hierarchically detecting hot-spots in massive VGI datasets, which is useful for understanding the pattern-shaping drivers that operate at multiple spatial scales. This research exemplifies a computational tool that is supported by high-performance computing and capable of efficiently detecting and visualizing multi-scale hot-spots in geospatial big data and contributes to expanding the toolbox for geospatial big data analytics.
Keywords	volunteered geographic information (VGI) ; geospatial big data ; point pattern analysis ; kernel density estimation ; hot-spot detection and visualization ; spatial bias ; Geography (General) ; G1-922
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)

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Article ; Online: Editorial

Wen Luo / Guiming Zhang

Frontiers in Earth Science, Vol

Advances and applications of geospatial modeling and analysis in digital twins

2023 Volume 11

Keywords	high-precision modeling ; scene recognition ; behavioral simulation ; smart cities ; smart coasts ; Science ; Q
Language	English
Publishing date	2023-05-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Spatial and Temporal Patterns in Volunteer Data Contribution Activities

Guiming Zhang

ISPRS International Journal of Geo-Information, Vol 9, Iss 597, p

A Case Study of eBird

2020 Volume 597

Abstract: Volunteered geographic information (VGI) has great potential to reveal spatial and temporal dynamics of geographic phenomena. However, a variety of potential biases in VGI are recognized, many of which root from volunteer data contribution activities. ... ...

Abstract	Volunteered geographic information (VGI) has great potential to reveal spatial and temporal dynamics of geographic phenomena. However, a variety of potential biases in VGI are recognized, many of which root from volunteer data contribution activities. Examining patterns in volunteer data contribution activities helps understand the biases. Using eBird as a case study, this study investigates spatial and temporal patterns in data contribution activities of eBird contributors. eBird sampling efforts are biased in space and time. Most sampling efforts are concentrated in areas of denser populations and/or better accessibility, with the most intensively sampled areas being in proximity to big cities in developed regions of the world. Reported bird species are also spatially biased towards areas where more sampling efforts occur. Temporally, eBird sampling efforts and reported bird species are increasing over the years, with significant monthly fluctuations and notably more data reported on weekends. Such trends are driven by the expansion of eBird and characteristics of bird species and observers. The fitness of use of VGI should be assessed in the context of applications by examining spatial, temporal and other biases. Action may need to be taken to account for the biases so that robust inferences can be made from VGI observations.
Keywords	volunteered geographic information (VGI) ; data contribution activities ; spatial and temporal patterns ; biases ; eBird ; Geography (General) ; G1-922
Subject code	310
Language	English
Publishing date	2020-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Detecting and Visualizing Observation Hot-Spots in Massive Volunteer-Contributed Geographic Data across Spatial Scales Using GPU-Accelerated Kernel Density Estimation

Zhang, Guiming

ISPRS international journal of geo-information. 2022 Jan. 12, v. 11, no. 1

2022

Abstract	Volunteer-contributed geographic data (VGI) is an important source of geospatial big data that support research and applications. A major concern on VGI data quality is that the underlying observation processes are inherently biased. Detecting observation hot-spots thus helps better understand the bias. Enabled by the parallel kernel density estimation (KDE) computational tool that can run on multiple GPUs (graphics processing units), this study conducted point pattern analyses on tens of millions of iNaturalist observations to detect and visualize volunteers’ observation hot-spots across spatial scales. It was achieved by setting varying KDE bandwidths in accordance with the spatial scales at which hot-spots are to be detected. The succession of estimated density surfaces were then rendered at a sequence of map scales for visual detection of hot-spots. This study offers an effective geovisualization scheme for hierarchically detecting hot-spots in massive VGI datasets, which is useful for understanding the pattern-shaping drivers that operate at multiple spatial scales. This research exemplifies a computational tool that is supported by high-performance computing and capable of efficiently detecting and visualizing multi-scale hot-spots in geospatial big data and contributes to expanding the toolbox for geospatial big data analytics.
Keywords	data analysis ; data quality ; spatial data ; statistical analysis
Language	English
Dates of publication	2022-0112
Publishing place	Multidisciplinary Digital Publishing Institute
Document type	Article
ZDB-ID	2655790-3
ISSN	2220-9964
ISSN	2220-9964
DOI	10.3390/ijgi11010055
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Enhancing VGI application semantics by accounting for spatial bias

Guiming Zhang

Big Earth Data, Vol 3, Iss 3, Pp 255-

2019 Volume 268

Abstract: Volunteered geographic information (VGI) is becoming an important source of geospatial big data that support many applications. The application semantics of VGI, i.e. how well VGI reflects the real-world geographic phenomena of interest to the ... ...

Abstract	Volunteered geographic information (VGI) is becoming an important source of geospatial big data that support many applications. The application semantics of VGI, i.e. how well VGI reflects the real-world geographic phenomena of interest to the application, is essential for any VGI applications. VGI observations often are spatially biased (e.g. spatially clustered). Spatial bias poses challenges on VGI application semantics because it may impede the quality of inferences made from VGI. Using species distribution modeling (SDM) as an example application, this article argues that spatial bias impedes VGI application semantics, as gauged by SDM model performance, and accounting for bias enhances application semantics. VGI observations from eBird were used in a case study for modeling the distribution of the American Robin (Turdus migratorius) in U.S. T. migratorius observations from the North American Breeding Bird Survey were used as independent validation data for model performance evaluation. A grid-based strategy was adopted to filter eBird species observations to reduce spatial bias. Evaluations show that spatial bias in species observations degrades SDM model performance and filtering species observations improves model performance. This study demonstrates that VGI application semantics can be enhanced by accounting for the spatial bias in VGI observations.
Keywords	volunteered geographic information (vgi) ; application semantics ; spatial bias ; species distribution modeling (sdm) ; Geography. Anthropology. Recreation ; G ; Geology ; QE1-996.5
Subject code	310
Language	English
Publishing date	2019-07-01T00:00:00Z
Publisher	Taylor & Francis Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Sarcomatoid renal pelvis carcinoma: Experience of treatment at a single-institution.

Liu, Tian / Yao, Yu / Geng, Chaoqun / Guan, Fengju / Zhang, Guiming

European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology

2024 Volume 50, Issue 6, Page(s) 108251

Abstract: Objectives: Sarcomatoid renal pelvis carcinoma (SRPC) is a rare variant of RPC. We aimed to summarize the clinicopathological features and prognostic factors of SRPC.: Methods: In this retrospective study, we collected data from 24 patients with SRPC ...

Abstract	Objectives: Sarcomatoid renal pelvis carcinoma (SRPC) is a rare variant of RPC. We aimed to summarize the clinicopathological features and prognostic factors of SRPC. Methods: In this retrospective study, we collected data from 24 patients with SRPC who were treated at the Department of Urology, Affiliated Hospital of Qingdao University between 2008 and 2021. The clinicopathological features of the patients were obtained from their medical records to evaluate the diagnosis, prognostic factors, and response to systemic therapy. Results: Immunohistochemical staining revealed that cytokeratin was expressed in 19 patients with SRPC, while vimentin was expressed in all patients. Computer tomography showed these tumors as low-density (n = 12) or mixed-density masses, with or without necrotic areas (n = 12). All patients showed different degrees of enhancement on computed tomography. Lymph node metastasis was present in 6 patients and distant metastasis in 5. The median survival of all patients was 28 months. Patients without metastasis had a median survival of 46 months compared with 18 months in those with metastasis (P < 0.05). Necrosis had no significant influence on prognosis (P > 0.05). The median survival of patients with and without hydronephrosis was 18 and 104 months (P < 0.05). Among patients without metastasis, those without hydronephrosis survived longer than those with hydronephrosis (104 vs 18 months, P < 0.05), and necrosis had no effect on prognosis. In patients with metastasis, necrosis and hydronephrosis had no effect on prognosis (P > 0.05). Conclusion: The prognosis of SRPC is poor, and the clinical stage, particularly the presence of distant metastasis, has a significant impact on prognosis.
Language	English
Publishing date	2024-03-05
Publishing country	England
Document type	Journal Article
ZDB-ID	632519-1
ISSN	1532-2157 ; 0748-7983
ISSN (online)	1532-2157
ISSN	0748-7983
DOI	10.1016/j.ejso.2024.108251
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Article ; Online: The time- and distance-decay effects of hurricane relevancy on social media

Mackenzie Kottwitz / Guiming Zhang / Jin Xu

Annals of GIS, Pp 1-

an empirical study of three hurricanes in the United States

2023 Volume 16

Abstract: ABSTRACTHurricane activity has been increasing in frequency and severity in recent years. This has serious implications for coastal and nearby communities who, when recovering from hurricanes, seek outside assistance from relevant government, non- ... ...

Abstract	ABSTRACTHurricane activity has been increasing in frequency and severity in recent years. This has serious implications for coastal and nearby communities who, when recovering from hurricanes, seek outside assistance from relevant government, non-governmental agencies, and nearby communities. The ever-increasing popularity of social media offers a new medium through which such social relevancy can be derived to inform targeted assistance-seeking efforts. This study utilizes Twitter to develop an understanding of disaster relevancy across space and time to establish a clearer context for impacted communities as to when and where assistance may be derived. Tweets were collected for three hurricanes within the contiguous United States (Hurricane Harvey in 2017, Florence in 2018 and Laura in 2020) and examined over a 12-week period following hurricane landfalls. The relationships between tweets and time and between tweets and distance were examined through correlation analysis. Results show statistically significant time- and distance-decay effects of hurricane relevancy on social media, though the time-decay effect was stronger. Most tweets occurred during the first week following hurricane landfall within the states wherein the hurricanes made landfall as well as around large cities. These findings could inform aid-seeking efforts in the event of hurricanes and other disasters.
Keywords	Hurricanes ; online relevancy ; social media ; distance- and time-decay ; Volunteered Geographic Information (VGI) ; Mathematical geography. Cartography ; GA1-1776
Language	English
Publishing date	2023-07-01T00:00:00Z
Publisher	Taylor & Francis Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Role of Human Monocarboxylate Transporter 1 (hMCT1) and 4 (hMCT4) in Tumor Cells and the Tumor Microenvironment.

Liu, Tian / Han, Shangcong / Yao, Yu / Zhang, Guiming

Cancer management and research

2023 Volume 15, Page(s) 957–975

Abstract: In recent years, the abnormal glucose metabolism of tumor cells has attracted increasing attention. Abnormal glucose metabolism is closely related to the occurrence and development of tumors. Monocarboxylate transporters (MCTs) transport the sugar ... ...

Abstract	In recent years, the abnormal glucose metabolism of tumor cells has attracted increasing attention. Abnormal glucose metabolism is closely related to the occurrence and development of tumors. Monocarboxylate transporters (MCTs) transport the sugar metabolites lactic acid and pyruvate, which affect glucose metabolism and tumor progression in a variety of ways. Thus, research has recently focused on MCTs and their potential functions in cancer. The MCT superfamily consists of 14 members. MCT1 and MCT4 play a crucial role in the maintenance of intracellular pH in tumor cells by transporting monocarboxylic acids (such as lactate, pyruvate and butyrate). MCT1 and MCT4 are highly expressed in a variety of tumor cells and are involved the proliferation, invasion and migration of tumor cells, which are closely related to the prognosis of cancer. Because of their important functions in tumor cells, MCT1 and MCT4 have become potential targets for cancer treatment. In this review, we focus on the structure, function and regulation of MCT1 and MCT4 and discuss the developed inhibitors of MCT1 and MCT4 to provide more comprehensive information that might aid in the development of strategies targeting MCTs in cancer.
Language	English
Publishing date	2023-09-04
Publishing country	New Zealand
Document type	Journal Article ; Review
ZDB-ID	2508013-1
ISSN	1179-1322
ISSN	1179-1322
DOI	10.2147/CMAR.S421771
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Fault Root Cause Tracking of the Mechanical Components of CNC Lathes Based on Information Transmission.

Zhang, Yingzhi / Guo, Guiming / Liu, Jialin

Sensors (Basel, Switzerland)

2023 Volume 23, Issue 9

Abstract: This study proposes a new method for the immediate fault warning and fault root tracing of CNC lathes. Here, the information acquisition scheme was formulated based on the analysis of the coupling relationship between the mechanical parts of CNC lathes. ... ...

Abstract	This study proposes a new method for the immediate fault warning and fault root tracing of CNC lathes. Here, the information acquisition scheme was formulated based on the analysis of the coupling relationship between the mechanical parts of CNC lathes. Once the collected status signals were de-noised and coarse-grained, transfer entropy theory was introduced to calculate the net entropy of information transfer between the mechanical parts, after which the information transfer model was constructed. The sliding window method was used to determine the probability threshold interval of the net information transfer entropy between the lathe mechanical parts under different processing modes. Therefore, the transition critical point was determined according to the information entropy, and the fault development process was clarified. By analyzing the information transfer changes between the parts, fault early warning and fault root tracking on the CNC lathe were realized. The proposed method realizes the digitalization and intelligentization of fault diagnosis and has the advantages of timely and efficient diagnosis. Finally, the effectiveness of the proposed method is verified by a numerical control lathe tool processing experiment.
Language	English
Publishing date	2023-04-30
Publishing country	Switzerland
Document type	Journal Article
ZDB-ID	2052857-7
ISSN	1424-8220 ; 1424-8220
ISSN (online)	1424-8220
ISSN	1424-8220
DOI	10.3390/s23094418
Database	MEDical Literature Analysis and Retrieval System OnLINE

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Article ; Online: Asymptomatic traumatic neuroma after neck dissection in a patient with thyroid cancer.

Zhu, Li / Zhang, Yujie / Zhou, Guiming / Meng, Zhaowei

Endokrynologia Polska

2022 Volume 73, Issue 5, Page(s) 907–908

Abstract: Not required for Clinical Vignette. ...

Abstract	Not required for Clinical Vignette.
MeSH term(s)	Humans ; Neck Dissection/adverse effects ; Neuroma/etiology ; Neuroma/surgery ; Thyroid Neoplasms/etiology ; Thyroid Neoplasms/surgery ; Thyroidectomy
Language	English
Publishing date	2022-08-16
Publishing country	Poland
Document type	Journal Article
ZDB-ID	419270-9
ISSN	2299-8306 ; 0423-104X
ISSN (online)	2299-8306
ISSN	0423-104X
DOI	10.5603/EP.a2022.0065
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bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
Jg. 1995 - 2021: Lesesall (1.OG)
ab Jg. 2022: Lesesaal (EG)

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