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probability sampling Protocol for Thematic and Spatial Quality Assessment of Classification Maps Generated From Spaceborne/Airborne Very High Resolution Images

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2014年第1期52卷 701-760页

作者： Baraldi, Andrea Boschetti, Luigi Humber, Michael L. Univ Maryland Dept Geog Sci College Pk MD 20742 USA Univ Maryland College Pk MD 20742 USA

To deliver sample estimates provided with the necessary probability foundation to permit generalization from the sample data subset to the whole target population being sampled, probability sampling strategies are required to satisfy three necessary not sufficient conditions: 1) All inclusion probabilities be greater than zero in the target population to be sampled. If some sampling units have an inclusion probability of zero, then a map accuracy assessment does not represent the entire target region depicted in the map to be assessed. 2) The inclusion probabilities must be: a) knowable for nonsampled units and b) known for those units selected in the sample: since the inclusion probability determines the weight attached to each sampling unit in the accuracy estimation formulas, if the inclusion probabilities are unknown, so are the estimation weights. This original work presents a novel (to the best of these authors' knowledge, the first) probability sampling protocol for quality assessment and comparison of thematic maps generated from spaceborne/airborne very high resolution images, where: 1) an original Categorical Variable Pair Similarity Index (proposed in two different formulations) is estimated as a fuzzy degree of match between a reference and a test semantic vocabulary, which may not coincide, and 2) both symbolic pixel-based thematic quality indicators (TQIs) and sub-symbolic object-based spatial quality indicators (SQIs) are estimated with a degree of uncertainty in measurement in compliance with the well-known Quality Assurance Framework for Earth Observation (QA4EO) guidelines. Like a decision-tree, any protocol (guidelines for best practice) comprises a set of rules, equivalent to structural knowledge, and an order of presentation of the rule set, known as procedural knowledge. The combination of these two levels of knowledge makes an original protocol worth more than the sum of its parts. The several degrees of novelty of the proposed probability sam

关键词： Contingency matrix error matrix land cover change (LCC) detection land cover classification maps comparison nonprobability sampling ontology overlapping area matrix (OAMTRX) probability sampling quality indicator of operativeness (OQI) spatial quality indicator (SQI) taxonomy thematic quality indicator (TQI)

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probability sampling BY CONNECTING SPACE WITH HOUSEHOLDS USING GIS/GPS TECHNOLOGIES

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JOURNAL OF SURVEY STATISTICS AND METHODOLOGY 2018年第2期6卷 149-168页

作者： Chen, Xinguang Hu, Hui Xu, Xiaohui Gong, Jie Yan, Yaqiong Li, Fang Univ Florida Dept Epidemiol Gainesville FL 32610 USA Texas A&M Hlth Sci Ctr Dept Epidemiol & Biostat College Stn TX 77843 USA Wuhan Ctr Dis Prevent & Control Wuhan 430022 Hubei Peoples R China

sampling methods for survey studies are challenged by the replacement of landline telephones with mobile phones, the lack of timely census data, and the growing need for studies to address new health challenges. GIS/GPS-assisted methods provide a promising alternative, but these methods need further improvement. We established a stratified 3-stage GIS/GPS-assisted sampling method in which residential areas of a target population are divided into mutually exclusive cells - geographic units (geounits) as the primary sampling frame (PSF). Geounits with residential households were randomly selected from the PSF with a semi-automatic algorithm implemented in R. Novel methods were used to sample households and participants. Simulations and application studies indicated adequate feasibility, efficiency and validity of the method in sampling rural-to-urban migrants from a large city with complex residential arrangements. With this method, researchers can determine sample size and number of geounits, households and participants to be sampled;optimally allocate geounits;determine area size of sampled geounits and estimate sample weights;and complete sampling for field data collection in a short period. Our method adds an integrative approach for GIS/GPS-assisted random sampling with a de facto population assumption. Additional evaluation studies are needed to assess the utility of this method in different settings.

关键词： Epidemiology GIS/GPS-assisted sampling probability sampling Survey studies

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Deep Adaptive Quadruplet Hashing With probability sampling for Large-Scale Image Retrieval

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2023年第12期33卷 7914-7927页

作者： Qin, Qibing Huang, Lei Xie, Kezhen Wei, Zhiqiang Wang, Chengduan Zhang, Wenfeng Weifang Univ Sch Comp Engn Weifang 261061 Peoples R China Ocean Univ China Fac Informat Sci & Engn Qingdao 266100 Peoples R China Chongqing Normal Univ Coll Comp & Informat Sci Chongqing 401331 Peoples R China Hangzhou Dianzi Univ Lishui Inst Lishui 310012 Peoples R China

With the preferable efficiency in storage and computation, hashing has shown potential application in large-scale multimedia retrieval. Compared with traditional hashing algorithms using hand-crafted characteristics, deep hashing inherits the representational capacity of deep neural networks to jointly learn semantic features and hash functions, encoding raw data into compact binary codes with significant discrimination. Generally, most of the current multi-wise hashing methods view the similarity margins between image pairs as constant values in training process. When the distance between sample pairs exceeds the fixed margin, the hashing network would not learn anything. Besides, available hashing methods commonly introduce the random sampling strategy to build training batches and ignore the sample distribution, which is harmful to parameter optimization. In this paper, we propose a novel Deep Adaptive Quadruplet Hashing with probability sampling (DAQH) for discriminative binary code learning. Specifically, with exploring the distribution relationship of raw samples, a non-uniform probability sampling strategy is proposed to build more informative and representative training batches, while maintaining the diversity of training samples. By introducing the prior similarity of sample pairs to calculate corresponding margins, an adaptive margin quadruplet loss is designed to dynamically preserve the underlying semantic relationships with its neighbors. To tune the attributes of binary codes, by combining quadruple regularization and orthogonality optimization, binary code constraint is developed to make the learned embedding with significant discrimination. Extensive experimental results on various benchmark datasets demonstrate our proposed DAQH framework achieves state-of-the-art visual similarity search performance.

关键词： Multimedia retrieval deep hashing adaptive margin probability sampling semantic relationships orthogonality optimization

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Efficient randomized Hough transform for circle detection using novel probability sampling and feature points

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OPTIK 2012年第20期123卷 1834-1840页

作者： Jiang, Lianyuan Guangxi Univ Technol Dept Comp Engn Liuzhou 545006 Guangxi Peoples R China

This paper presents an efficient randomized Hough transform algorithm for circle detection. It optimizes the methods for determining sample points and finding candidate circles. Due to these two optimizations, sampling validity is improved and many false circles are prevented from being regarded as candidate circles. Experimental results demonstrate that the proposed algorithm, which features a strong robustness and high resolution, can dramatically speed up circle detection as compared to other algorithms. It can also be applied to detect ellipses. (c) 2012 Elsevier GmbH. All rights reserved.

关键词： Randomized Hough transform Circle detection probability sampling Candidate circle Extreme point

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Comparing convenience and probability sampling for urban ecology applications

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JOURNAL OF APPLIED ECOLOGY 2018年第5期55卷 2332-2342页

作者： Speak, Andrew Escobedo, Francisco J. Russo, Alessio Zerbe, Stefan Free Univ Bozen Bolzano Bolzano Italy Univ Rosario Fac Nat Sci & Math Bogota Colombia Far Eastern Fed Univ Lab Urban & Landscape Design Vladivostok Russia

1. Urban forest ecosystems confer multiple ecosystem services. There is therefore a need to quantify ecological characteristics in terms of community structure and composition so that benefits can be better understood in ecosystem service models. Efficient sampling and monitoring methods are crucial in this process. 2. Full tree inventories are scarce due to time and financial constraints, thus a variety of sampling methods exist. Modern vegetation surveys increasingly use a stratified-random plot-based sampling to reduce the bias associated with convenience sampling, even though the latter can save time and increase species richness scores. The urban landscape, with a high degree of conspecific clustering and high species diversity, provides a unique biogeographical case for comparing these two methodological approaches. 3. We use two spatially extensive convenience samples of the urban forest of Meran (Italy), and compare the community structure, tree characteristics and ecosystem service provision with 200 random circular plots. 4. The convenience sampling resulted in a higher species diversity, incorporating more rare species. This is a result of covering more area per unit sampling time. Pseudorandom subplots were compared to the random plots revealing similar Shannon diversity and sampling comparability indices. Measured tree variables (diameter at breast height, height, tree-crown width, height to crown base) were similar between the two methods, as were ecosystem service model outputs. 5. Synthesis and applications. Our results suggest that convenience sampling may be a time and money saving alternative to random sampling as long as stratification by land-use type is incorporated into the design. The higher species richness can potentially improve the accuracy of urban ecological models, which rely on species-specific functional traits.

关键词： beta diversity convenience sampling ecosystem services heterogeneity probability sampling pseudosampling urban ecosystem urban forest structure

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How might opinion polls be improved?: The case for probability sampling

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JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES A-STATISTICS IN SOCIETY 1996年第1期159卷 21-28页

作者： Lynn, P Jowell, R Social and Community Planning Research London UK

A classification of sources of error in opinion polling is presented, and related to investigations of observed error in the polls at the time of the 1992 general election. This leads directly to implications for reducing the potential for error in future. It is argued that quota sampling bias, incorporating both selection bias and unit non-response bias, is a major source of error. The adoption of probability sampling methods is proposed as a way to reduce this bias, and pollsters and their clients are encouraged to experiment with such methods. An example of a practical probability sampling design is described. Other sources of error which have been identified, and for which methodological improvement is suggested, are the treatment of item refusals, the treatment of those who say they 'don't know' for whom they will vote and the treatment of respondents' predictions of whether they will vote.

关键词： non-response opinion polls probability sampling quota sampling response error sampling bias

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Sampled to Death? The Rise and Fall of probability sampling in Archaeology

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AMERICAN ANTIQUITY 2021年第1期86卷 43-60页

作者： Banning, Edward B. Univ Toronto Dept Anthropol 19 Russell St Toronto ON M5S 2S2 Canada

After a heyday in the 1970s and 1980s, probability sampling became much less visible in archaeological literature as it came under assault from the post-processual critique and the widespread adoption of "full-coverage survey." After 1990, published discussion of probability sampling rarely strayed from sample-size issues in analyses of artifacts along with plant and animal remains, and most textbooks and archaeological training limited sampling to regional survey and did little to equip new generations of archaeologists with this critical aspect of research design. A review of the last 20 years of archaeological literature indicates a need for deeper and broader archaeological training in sampling;more precise usage of terms such as "sample";use of randomization as a control in experimental design;and more attention to cluster sampling, stratified sampling, and nonspatial sampling in both training and research.

关键词： probability sampling statistics survey history of archaeology archaeological pedagogy

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Quota sampling as an Alternative to probability sampling? An Experimental Study

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SOCIOLOGICAL RESEARCH ONLINE 2014年第1期19卷 56 - 66页

作者： Yang, Keming Banamah, Ahmad Univ Durham Durham DH1 3HP England

In spite of the establishment of probability sampling methods since the 1930s, non-probability sampling methods have remained popular among many commercial and polling agents, and they have also survived the embarrassment from a few incorrect predictions in American presidential elections. The increase of costs and the decline of response rates for administering probability samples have led some survey researchers to search for a non-probability sampling method as an alternative to probability sampling. In this study we aim to test whether results from a quota sample, believed to be the non-probability sampling method that is the closest in representativeness to probability sampling, are statistically equivalent to those from a probability sample. Further, we pay special attention to the effects of the following two factors for understanding the difference between the two sampling methods: the survey's topic and the response rate. An experimental survey on social capital was conducted in a student society in Northeast England. The results suggest that the survey topic influences who responded and that the response rate was associated with the sample means as well. For these reasons, we do not think quota sampling should be taken as an acceptable alternative to probability sampling.

关键词： probability sampling Quota sampling Representativeness Response Rate Social Capital

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Sweet tweets! Evaluating a new approach for probability-based sampling of Twitter

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EPJ DATA SCIENCE 2022年第1期11卷 1-32页

作者： Buskirk, Trent D. Blakely, Brian P. Eck, Adam McGrath, Richard Singh, Ravinder Yu, Youzhi Bowling Green State Univ Bowling Green OH 43403 USA

As survey costs continue to rise and response rates decline, researchers are seeking more cost-effective ways to collect, analyze and process social and public opinion data. These issues have created an opportunity and interest in expanding the fit-for-purpose paradigm to include alternate sources such as passively collected sensor data and social media data. However, methods for accessing, sourcing and sampling social media data are just now being developed. In fact, there has been a small but growing body of literature focusing on comparing different Twitter data access methods through either the elaborate firehose or the free Twitter search or streaming APIs. Missing from the literature is a good understanding of how to randomly sample Tweets to produce datasets that are representative of the daily discourse, especially within geographical regions of interest, without requiring a census of all Tweets. This understanding is necessary for producing quality estimates of public opinion from social media sources such as Twitter. To address this gap, we propose and test the Velocity-Based Estimation for sampling Tweets (VBEST) algorithm for selecting a probability based sample of tweets. We compare the performance of VBEST sample estimates to other methods of accessing Twitter through the Search API on the distribution of total Tweets as well as COVID-19 keyword incidence and frequency and find that the VBEST samples produce consistent and relatively low levels of overall bias compared to common methods of access through the Search API across many experimental conditions.

关键词： Twitter probability sampling Tweets Social media COVID-19 Big data Survey research

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Combining quota and probability sub-sampling within enumeration areas to produce more reliable estimates

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Statistical Journal of the IAOS 2022年第4期38卷 1399-1410页

作者： Coelho, Isabela Bertolini Pitta, Marcelo Trindade Silva, Pedro Luis Do Nascimento Brazilian Network Information Center (NIC.br) SP Brazil National School of Statistical Sciences RJ Brazil

Traditional surveys face increasing challenges due to rising non-response rates and the diminishing resources available to survey organizations. A recently proposed solution involves the combination of non-probability sample surveys (often cheaper) with probability sample surveys (more expensive), using the latter as a reference to weight the former. Considering a special case in which a single survey was designed and carried out by simultaneously using the two sampling approaches within a single field operation, this paper compared the use of quasi-randomization and sample matching methods to assign weights to the non-probability part of the sample. The quasi-randomization method provided the closest point estimates and smaller standard errors (on average) when compared to the benchmark estimates. © 2022 - IOS Press. All rights reserved.

关键词： combining samples Non-probability sampling probability sampling quota sampling survey weighting

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