Spatial heterogeneity is an inherent characteristic of natural forest landscapes, therefore estimation of structural variability, including the collection and analyzing of field measurements, is a growing challenge fo...Spatial heterogeneity is an inherent characteristic of natural forest landscapes, therefore estimation of structural variability, including the collection and analyzing of field measurements, is a growing challenge for monitoring wildlife habitat di- versity and ecosystem sustainability. In this study, we investigated the combined influence of plot shape and size on the accuracy of assessment of conventional and rare structural features in two young-growth spruce-dominated forests in northwestern China. We used a series of inventory schemes and analytical approaches. Our data showed that options for sampling protocols, especially the selection of plot size considered in structural attributes measurement, dramatically af- fect the minimum number of plots required to meet a certain accuracy criteria. The degree of influence of plot shape is related to survey objectives; thus, effects of plot shape differ for evaluations of the ＂mean＂ or ＂representative＂ stand structural conditions from that for the range of habitat （in extreme values）. Results of Monte Carlo simulations suggested that plot sizes 〈0.1 ha could be the most efficient way to sample for conventional characteristics （features with relative constancy within a site, such as stem density）. Also, 0.25 ha or even larger plots may have a greater likelihood of capturing rare structural attributes （features possessing high randomness and spatial heterogeneity, such as volume of coarse woody debris） in our forest type. These findings have important implications for advisable sampling protocol （plot size and shape） to adequately capture information on forest habitat structure and diversity; such efforts must be based on a clear definition of which types are structural attributes to measure.展开更多
The laboratories in the bauxite processing industry are always under a heavy workload of sample collection, analysis, and compilation of the results. After size reduction from grinding mills, the samples of bauxite ar...The laboratories in the bauxite processing industry are always under a heavy workload of sample collection, analysis, and compilation of the results. After size reduction from grinding mills, the samples of bauxite are collected after intervals of 3 to 4 hours. Large bauxite processing industries producing 1 million tons of pure aluminium can have three grinding mills. Thus, the total number of samples to be tested in one day reaches a figure of 18 to 24. The sample of bauxite ore coming from the grinding mill is tested for its particle size and composition. For testing the composition, the bauxite ore sample is first prepared by fusing it with X-ray flux. Then the sample is sent for X-ray fluorescence analysis. Afterwards, the crucibles are washed in ultrasonic baths to be used for the next testing. The whole procedure takes about 2 - 3 hours. With a large number of samples reaching the laboratory, the chances of error in composition analysis increase. In this study, we have used a composite sampling methodology to reduce the number of samples reaching the laboratory without compromising their validity. The results of the average composition of fifteen samples were measured against composite samples. The mean of difference was calculated. The standard deviation and paired t-test values were evaluated against predetermined critical values obtained using a two-tailed test. It was found from the results that paired test-t values were much lower than the critical values thus validating the composition attained through composite sampling. The composite sampling approach not only reduced the number of samples but also the chemicals used in the laboratory. The objective of improved analytical protocol to reduce the number of samples reaching the laboratory was successfully achieved without compromising the quality of analytical results.展开更多
BACKGROUND Microvascular invasion(MVI)is a critical prognostic factor for postoperative hepatocellular carcinoma recurrence,but the reliability of its current pathological diagnosis remains uncertain.AIM To evaluate t...BACKGROUND Microvascular invasion(MVI)is a critical prognostic factor for postoperative hepatocellular carcinoma recurrence,but the reliability of its current pathological diagnosis remains uncertain.AIM To evaluate the accuracy of current 7-point sampling methods and propose an optimal pathological protocol using whole-mount slide imaging(WSI)for better MVI detection.METHODS We utilized 40 New Zealand white rabbits to establish VX2 liver tumor models.The entire tumor-containing liver lobe was subsequently obtained,following which five different sampling protocols(A-E)were employed to evaluate the detection rate,accuracy,quantity,and distribution of MVI,with the aim of identifying the optimal sampling method.RESULTS VX2 liver tumor models were successfully established in 37 rabbits,with an incidence of MVI of 81.1%(30/37).The detection rates[27%(10/37),43%(16/37),62%(23/37),68%(25/37),and 93%(14/15)]and quantity(15,36,107,125,and 395)of MVI increased significantly from protocols A to E.The distribution of MVI showed fewer MVIs farther away from the tumor,but the percentage of MVI detected quantity gradually increased from 6.7%to 48.3%in the distant nonneoplastic liver tissue from protocols A to E.Protocol C was identified as the optimal sampling method by comparing them in sequence.The sampling protocol of three consecutive interval WSIs at the tumor center(WSI3)was further screened to determine the optimal number of WSIs.Protocol A(7-point sampling method)exhibited only 46%accuracy and a high false-negative rate of 67%.Notably,the WSI3 protocol improved the accuracy to 78%and decreased the false-negative rate to 27%.CONCLUSION The current 7-point sampling method has a high false-negative rate in MVI detection.In contrast,the WSI3 protocol provides a practical and effective approach to improve MVI diagnostic accuracy,which is crucial for hepatocellular carcinoma diagnosis and treatment planning.展开更多
Sensing is a fundamental process to acquire information in the physical world for computation. Existing models treat a sensing process as an indivisible whole, such that sampling and reconstructing of signals are desi...Sensing is a fundamental process to acquire information in the physical world for computation. Existing models treat a sensing process as an indivisible whole, such that sampling and reconstructing of signals are designed to be highly associated with each other in a unified procedure. These strongly coupled sensing systems are efficient, but usually lack reusability and upgradeability. We propose a functional sensing model called SDR （Sampling-Design-Reconstruction） to decouple a sensing process into two modules： sampling protocol and reconstruction algorithm. The core of this decoupling is a design space, which is a common data structure constructed using functions of the sensing target as prior knowledge, to seamlessly bridge the sampling protocol and reconstruction household electricity usage sensing systems can be successfully algorithm together. We demonstrate that existing types of decoupled by introducing corresponding design spaces.展开更多
基金supported by the Hundred Talents Program of the Chinese Academy of Sciences(No.29Y127D11)the National Natural Science Foundation of China(No.41271524)+1 种基金Natural Science Foundation of Gansu Province(No.1210RJDA015)Forestry Industry Research Special Funds for Public Welfare Projects(No.201104009-08)
文摘Spatial heterogeneity is an inherent characteristic of natural forest landscapes, therefore estimation of structural variability, including the collection and analyzing of field measurements, is a growing challenge for monitoring wildlife habitat di- versity and ecosystem sustainability. In this study, we investigated the combined influence of plot shape and size on the accuracy of assessment of conventional and rare structural features in two young-growth spruce-dominated forests in northwestern China. We used a series of inventory schemes and analytical approaches. Our data showed that options for sampling protocols, especially the selection of plot size considered in structural attributes measurement, dramatically af- fect the minimum number of plots required to meet a certain accuracy criteria. The degree of influence of plot shape is related to survey objectives; thus, effects of plot shape differ for evaluations of the ＂mean＂ or ＂representative＂ stand structural conditions from that for the range of habitat （in extreme values）. Results of Monte Carlo simulations suggested that plot sizes 〈0.1 ha could be the most efficient way to sample for conventional characteristics （features with relative constancy within a site, such as stem density）. Also, 0.25 ha or even larger plots may have a greater likelihood of capturing rare structural attributes （features possessing high randomness and spatial heterogeneity, such as volume of coarse woody debris） in our forest type. These findings have important implications for advisable sampling protocol （plot size and shape） to adequately capture information on forest habitat structure and diversity; such efforts must be based on a clear definition of which types are structural attributes to measure.
文摘The laboratories in the bauxite processing industry are always under a heavy workload of sample collection, analysis, and compilation of the results. After size reduction from grinding mills, the samples of bauxite are collected after intervals of 3 to 4 hours. Large bauxite processing industries producing 1 million tons of pure aluminium can have three grinding mills. Thus, the total number of samples to be tested in one day reaches a figure of 18 to 24. The sample of bauxite ore coming from the grinding mill is tested for its particle size and composition. For testing the composition, the bauxite ore sample is first prepared by fusing it with X-ray flux. Then the sample is sent for X-ray fluorescence analysis. Afterwards, the crucibles are washed in ultrasonic baths to be used for the next testing. The whole procedure takes about 2 - 3 hours. With a large number of samples reaching the laboratory, the chances of error in composition analysis increase. In this study, we have used a composite sampling methodology to reduce the number of samples reaching the laboratory without compromising their validity. The results of the average composition of fifteen samples were measured against composite samples. The mean of difference was calculated. The standard deviation and paired t-test values were evaluated against predetermined critical values obtained using a two-tailed test. It was found from the results that paired test-t values were much lower than the critical values thus validating the composition attained through composite sampling. The composite sampling approach not only reduced the number of samples but also the chemicals used in the laboratory. The objective of improved analytical protocol to reduce the number of samples reaching the laboratory was successfully achieved without compromising the quality of analytical results.
基金Supported by the National Natural Science Foundation of China,No.82072038 and No.82371975.
文摘BACKGROUND Microvascular invasion(MVI)is a critical prognostic factor for postoperative hepatocellular carcinoma recurrence,but the reliability of its current pathological diagnosis remains uncertain.AIM To evaluate the accuracy of current 7-point sampling methods and propose an optimal pathological protocol using whole-mount slide imaging(WSI)for better MVI detection.METHODS We utilized 40 New Zealand white rabbits to establish VX2 liver tumor models.The entire tumor-containing liver lobe was subsequently obtained,following which five different sampling protocols(A-E)were employed to evaluate the detection rate,accuracy,quantity,and distribution of MVI,with the aim of identifying the optimal sampling method.RESULTS VX2 liver tumor models were successfully established in 37 rabbits,with an incidence of MVI of 81.1%(30/37).The detection rates[27%(10/37),43%(16/37),62%(23/37),68%(25/37),and 93%(14/15)]and quantity(15,36,107,125,and 395)of MVI increased significantly from protocols A to E.The distribution of MVI showed fewer MVIs farther away from the tumor,but the percentage of MVI detected quantity gradually increased from 6.7%to 48.3%in the distant nonneoplastic liver tissue from protocols A to E.Protocol C was identified as the optimal sampling method by comparing them in sequence.The sampling protocol of three consecutive interval WSIs at the tumor center(WSI3)was further screened to determine the optimal number of WSIs.Protocol A(7-point sampling method)exhibited only 46%accuracy and a high false-negative rate of 67%.Notably,the WSI3 protocol improved the accuracy to 78%and decreased the false-negative rate to 27%.CONCLUSION The current 7-point sampling method has a high false-negative rate in MVI detection.In contrast,the WSI3 protocol provides a practical and effective approach to improve MVI diagnostic accuracy,which is crucial for hepatocellular carcinoma diagnosis and treatment planning.
基金Supported by the Strategic Priority Program of the Chinese Academy of Sciences under Grant No.XDA06010401the NationalBasic Research 973 Program of China under Grant Nos.2011CB302800,2011CB302502the Guangdong Talents Program of Chinaunder Grant No.201001D0104726115
文摘Sensing is a fundamental process to acquire information in the physical world for computation. Existing models treat a sensing process as an indivisible whole, such that sampling and reconstructing of signals are designed to be highly associated with each other in a unified procedure. These strongly coupled sensing systems are efficient, but usually lack reusability and upgradeability. We propose a functional sensing model called SDR （Sampling-Design-Reconstruction） to decouple a sensing process into two modules： sampling protocol and reconstruction algorithm. The core of this decoupling is a design space, which is a common data structure constructed using functions of the sensing target as prior knowledge, to seamlessly bridge the sampling protocol and reconstruction household electricity usage sensing systems can be successfully algorithm together. We demonstrate that existing types of decoupled by introducing corresponding design spaces.
