It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional (3D) straindistribution i...It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional (3D) straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography (DVSP) technique in conjunction with X-ray computedtomography (CT) and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shr...Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shrub-grasses (G) separately in a subtropical forest area in Nanjing, China. Both upward and downward photographs were taken with a digital camera in 72 quadrats (10 m × 10 m each). Fifteen models were established and validated. Models jointly using both T and G performed better than those using the T and G separately. The best model, TG = T + G- 1.134 × T × G- 0.025 (R2 = 0.9115, P < 0.01, root mean squared error = 0.0789), is recommended for application. This model provides a good way to obtain total forest VFC values through taking tree and shrub-grass photos on ground below tree canopy rather than above tree canopy.展开更多
Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,pr...Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,providing a more scientific and macroscopic way of research.The key to refinement design is to refine the spatial design process and the spatial improvement strategy system.Taking the ancient city of Zhaoyu in Qixian County,Shanxi Province as an example,(1)based on obtaining the integrated data of the ancient city through the drone tilt photography,the style and landscape of the ancient city are modeled;(2)the point cloud data with spatial information is imported into the point cloud analysis platform and the data analysis is carried out from the overall macroscopic style of the ancient city to the refinement level,which results in the formation of a more intuitive landscape design scheme,thus improving the precision and practicability of the landscape design;(3)Based on spatial big data,it starts from the spatial aggregation level,spatial distribution characteristics and other evaluation index system to achieve the refinement analysis of the site.Digital technology and methods are used throughout the process to explore the refined design path.展开更多
External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative c...External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative carious lesions. This study investigated the diagnostic value of digital subtraction radiography in detecting external root resorption. This was a descriptive study conducted using the lab trial method. Artificially-induced external root resorption was created in different sizes at the coronal and apical aspects of 20 premolar teeth. Digital radiographs were obtained of each tooth under standard conditions and these radiographs were subtracted by imaging devices. The subtracted images and the digital radiographs were observed by three radiologists. Chi-square, Kappa test, and Z-test were used to analyze the data. The mean of general sensitivity of digital subtraction radiography and direct digital radiography was low in diagnosing 0.05 mm lesions (Sen = 35%), yet, the accuracy index was good for all lesions (Acc ≥ 65%). Other diagnostic parameters were also acceptable. Both types of radiography worked better in diagnosing coronal than apical lesions (P > 0.05). The interpreters (observers) showed a better performance in diagnosing external root resorption using digital subtraction radiography compared to digital radiography. Both modalities were exact and accurate in detecting 0.05 mm lesions as well as other lesions. However, the results of digital subtraction radiography were not significantly different from those of direct digital radiography.展开更多
Aim: Detection of calcified carotid atheroma (CCA) has an important role in reducing the incidence of Cerebro Vascular Accident (CVA). The aim of this study was to evaluate efficacy of panoramic digital radiography in...Aim: Detection of calcified carotid atheroma (CCA) has an important role in reducing the incidence of Cerebro Vascular Accident (CVA). The aim of this study was to evaluate efficacy of panoramic digital radiography in detecting atherosclerosis. Methods: It is descriptive-analytical diagnostic study. The people (22 to 62 years old) were referred to a radiology clinic to perform panoramic radiography for diagnosis of CCA. Individuals who were suspected were introduced to the radiology department of dental school to undergo ultrasound evaluation to CCA. For the 41 patients (55 sides), ultrasound was performed. For data analysis, the Chi-square and Fisher's exact test were used. Results: The prevalence of CCA was 2.43%. The PPV of digital panoramic was 45.5%. There was no significant relationship between age (P = 0.14) and sex (P = 0.539) and PPV of digital panoramic. The PPV of digital panoramic was significantly associated with hypertension (P = 0.032). Conclusion: It seems that panoramic can be used to screen patients with a history of hypertension for atherosclerosis.展开更多
Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An a...Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.展开更多
Assessment of entrance skin doses for patients in Digital radiography examinations should be made as a means for the optimization of the radiation protection of the patients. We measured the entrance skin dose (ESD) r...Assessment of entrance skin doses for patients in Digital radiography examinations should be made as a means for the optimization of the radiation protection of the patients. We measured the entrance skin dose (ESD) received by 50 pediatrics undergoing 12 types of diagnostic X-ray examination at Radiology Department of Asser Central Hospital-KSA. The entrance skin dose ESD was determined via measurements parameters: focus to skin distance (FSD), tube current (mAs) and tube voltage (kV) in arithmetical equation. The mean ± SD for ESDs were found to be 0.16 ± 0.03, 0.21 ± 0.01, 0.63 ± 0.26, 0.55 ± 0.09, 0.15 ± 0.05, 0.27 ± 0.06, 0.41 ± 0.19, 0.46 ± 0.18, 0.46 ± 0.12, 0.20 ± 0.02, 0.39 ± 0.01, 0.29 ± 0.03, for PA chest, foot, AP pelvis, PA skull, PA hand, AP arm, ankle, AP shoulder, abdomen, forearm, AP femur, AP elbow consequently. Our study is considered as an attempt to evaluate the ESDs received by digital radiographic x-ray machine for children aged between 2 - 15 years old, taking in our considerations number of other variables. The mean ESD values obtained are found to be within the standard reference. The data obtained may add to the available information in national records for general use. It may provide guidance on where efforts on dose reduction will need to be directed to fulfill the requirements of the optimization process and serve as a reference for future researches.展开更多
Background:Digital hemispherical photography(DHP)is widely used to estimate the leaf area index(LAI)of forest plots due to its advantages of high efficiency and low cost.A crucial step in the LAI estimation of forest ...Background:Digital hemispherical photography(DHP)is widely used to estimate the leaf area index(LAI)of forest plots due to its advantages of high efficiency and low cost.A crucial step in the LAI estimation of forest plots via DHP is choosing a sampling scheme.However,various sampling schemes involving DHP have been used for the LAI estimation of forest plots.To date,the impact of sampling schemes on LAI estimation from DHP has not been comprehensively investigated.Methods:In this study,13 commonly used sampling schemes which belong to five sampling types(i.e.dispersed,square,cross,transect and circle)were adopted in the LAI estimation of five Larix principis-rupprechtii plots(25m×25 m).An additional sampling scheme(with a sample size of 89)was generated on the basis of all the sample points of the 13 sampling schemes.Three typical inversion models and four canopy element clumping index(Ωe)algorithms were involved in the LAI estimation.The impacts of the sampling schemes on four variables,including gap fraction,Ωe,effective plant area index(PAIe)and LAI estimation from DHP were analysed.The LAI estimates obtained with different sampling schemes were then compared with those obtained from litter collection measurements.Results:Large differences were observed for all four variable estimates(i.e.gap fraction,Ωe,PAIe and LAI)under different sampling schemes.The differences in impact of sampling schemes on LAI estimation were not obvious for the three inversion models,if the fourΩe algorithms,except for the traditional gap-size analysis algorithm were adopted in the estimation.The accuracy of LAI estimation was not always improved with an increase in sample size.Moreover,results indicated that with the appropriate inversion model,Ωe algorithm and sampling scheme,the maximum estimation error of DHP-estimated LAI at elementary sampling unit can be less than 20%,which is required by the global climate observing system,except in forest plots with extremely large LAI values(~>6.0).However,obtaining an LAI from DHP with an estimation error lower than 5%is impossible regardless of which combination of inversion model,Ωe algorithm and sampling scheme is used.Conclusion:The LAI estimation of L.principis-rupprechtii forests from DHP was largely affected by the sampling schemes adopted in the estimation.Thus,the sampling scheme should be seriously considered in the LAI estimation.One square and two transect sampling schemes(with sample sizes ranging from 3 to 9)were recommended to be used to estimate the LAI of L.principis-rupprechtii forests with the smallest mean relative error(MRE).By contrast,three cross and one dispersed sampling schemes were identified to provide LAI estimates with relatively large MREs.展开更多
Rheumatoid arthritis is a chronic multisystem disease of unknown cause. The characteristic feature of RA is persistent inflammatory synovitis. The natural history of disease is such that the early months of the diseas...Rheumatoid arthritis is a chronic multisystem disease of unknown cause. The characteristic feature of RA is persistent inflammatory synovitis. The natural history of disease is such that the early months of the disease are critical period during which reversible joint damage occurs. So early diagnosis of RA and appropriate drug application is the only way to save a patient from this crippling disease. In India, the cost of investigations is a significant factor for most of the patients. Ultrasonography or Power Doppler Ultra Sound (PDUS) has the advantage of being economic in spite of its sensitivity in assessing both inflammatory and destructive changes. The aim of the present study was to evaluate the diagnostic efficiency of PDUS in early rheumatoid arthritis. The study was performed with the patients attending Rheumatology Clinic. A total number of 106 patients of clinically suspected rheumatoid arthritis were studied as per selection criteria. Radiological examinations of hands were done by digital radiography and PDUS in a group of 53 patients, assessment of foot changes by PDUS and Digital Radiography were done in another similar group of 53 patients. Final diagnosis by ACR EULAR-2010 criteria is done for all the patients. The comparative study reveals that synovial vascularity as demonstrated by PDUS is much more effective in diagnosing early rheumatoid arthritis, both in hand and in feet than digital radiograph. PDUS of feet may yield earlier and better findings than hands, which is conventionally used in patients suffering from early rheumatoid arthritis.展开更多
In the following work of research, we shall present the results of a study on forms of digital photographic socialization as carried out by the so-called "digital natives" in order to explore their competence in man...In the following work of research, we shall present the results of a study on forms of digital photographic socialization as carried out by the so-called "digital natives" in order to explore their competence in managing digital photographic output and cultural practices. This shall be done under the following categories of analysis: snapshot, organization, socialization, reception, privacy, and copyrights in digital photography. The study explores the forms of digital photography production, technical problems of photographic management and the final uses that digital photographers give to their photos in terms of web tools 2.0, mobile telephones and social networks. Digital photography technology, compact cameras, mobile phones with cameras, specialized websites in photography and the lnternet generate new forms of production and emerging styles of digital photographic socialization. The study is carried out using a defined sample of university students, those digital natives who create and use digital photography.展开更多
In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration...In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration. Therefore, the design result has comparative randomicity and "gaps" are expected. An aerial photography design system is developed by analyzing the terrain undulation influence to the design result with DEM data so that the forward overlap and side overlap can be justified according to the block terrain undulation to meet specifications or standards. The data designed by this system is compared with the real flying data. The results show that making use of DEM to assist in aerial photography design can ensure that the designed result fits the real terrain better.展开更多
Two speckle patterns are recorded using a video cameracorresponding to undisplaced and displaced states into the memory ofa computer. After one pattern is added to another, the displacementof the measured points can b...Two speckle patterns are recorded using a video cameracorresponding to undisplaced and displaced states into the memory ofa computer. After one pattern is added to another, the displacementof the measured points can be calculated by using the Fouriertransform. The expression of displacement field is deduced fornon-uniform displacement, and as an example, a rotatanle disc istested for illustration. The re- sults prove that the present methodis promising.展开更多
基金financially supported by National Basic Research Program of China (973 Program) (No. 2010CB732002)National Natural Science Foundation of China (Nos. 51374211, 51374215)+1 种基金National Key Foundation for Exploring Scientific Instrument of China (No. 2013YQ240803)Fundamental Research Funds for the Central Universities (No. 2009QM02)
文摘It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional (3D) straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography (DVSP) technique in conjunction with X-ray computedtomography (CT) and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
基金Supported by the National Basic Research Program (973 Program) of China (No.2007CB407206)the National Natural Science Foundation of China (No.40371053)
文摘Vegetation fractional coverage (VFC) is one of the key indicators of vegetation distribution. In the work a measurement-based model was developed to derive total forest VFC (TG) as well as the VFC of trees (T) and shrub-grasses (G) separately in a subtropical forest area in Nanjing, China. Both upward and downward photographs were taken with a digital camera in 72 quadrats (10 m × 10 m each). Fifteen models were established and validated. Models jointly using both T and G performed better than those using the T and G separately. The best model, TG = T + G- 1.134 × T × G- 0.025 (R2 = 0.9115, P < 0.01, root mean squared error = 0.0789), is recommended for application. This model provides a good way to obtain total forest VFC values through taking tree and shrub-grass photos on ground below tree canopy rather than above tree canopy.
文摘Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,providing a more scientific and macroscopic way of research.The key to refinement design is to refine the spatial design process and the spatial improvement strategy system.Taking the ancient city of Zhaoyu in Qixian County,Shanxi Province as an example,(1)based on obtaining the integrated data of the ancient city through the drone tilt photography,the style and landscape of the ancient city are modeled;(2)the point cloud data with spatial information is imported into the point cloud analysis platform and the data analysis is carried out from the overall macroscopic style of the ancient city to the refinement level,which results in the formation of a more intuitive landscape design scheme,thus improving the precision and practicability of the landscape design;(3)Based on spatial big data,it starts from the spatial aggregation level,spatial distribution characteristics and other evaluation index system to achieve the refinement analysis of the site.Digital technology and methods are used throughout the process to explore the refined design path.
文摘External root resorption can induce the degeneration of dental cementum and dentine and may extend towards the pulp reductive. Digital subtraction radiography can function as a useful tool in diagnosing degenerative carious lesions. This study investigated the diagnostic value of digital subtraction radiography in detecting external root resorption. This was a descriptive study conducted using the lab trial method. Artificially-induced external root resorption was created in different sizes at the coronal and apical aspects of 20 premolar teeth. Digital radiographs were obtained of each tooth under standard conditions and these radiographs were subtracted by imaging devices. The subtracted images and the digital radiographs were observed by three radiologists. Chi-square, Kappa test, and Z-test were used to analyze the data. The mean of general sensitivity of digital subtraction radiography and direct digital radiography was low in diagnosing 0.05 mm lesions (Sen = 35%), yet, the accuracy index was good for all lesions (Acc ≥ 65%). Other diagnostic parameters were also acceptable. Both types of radiography worked better in diagnosing coronal than apical lesions (P > 0.05). The interpreters (observers) showed a better performance in diagnosing external root resorption using digital subtraction radiography compared to digital radiography. Both modalities were exact and accurate in detecting 0.05 mm lesions as well as other lesions. However, the results of digital subtraction radiography were not significantly different from those of direct digital radiography.
文摘Aim: Detection of calcified carotid atheroma (CCA) has an important role in reducing the incidence of Cerebro Vascular Accident (CVA). The aim of this study was to evaluate efficacy of panoramic digital radiography in detecting atherosclerosis. Methods: It is descriptive-analytical diagnostic study. The people (22 to 62 years old) were referred to a radiology clinic to perform panoramic radiography for diagnosis of CCA. Individuals who were suspected were introduced to the radiology department of dental school to undergo ultrasound evaluation to CCA. For the 41 patients (55 sides), ultrasound was performed. For data analysis, the Chi-square and Fisher's exact test were used. Results: The prevalence of CCA was 2.43%. The PPV of digital panoramic was 45.5%. There was no significant relationship between age (P = 0.14) and sex (P = 0.539) and PPV of digital panoramic. The PPV of digital panoramic was significantly associated with hypertension (P = 0.032). Conclusion: It seems that panoramic can be used to screen patients with a history of hypertension for atherosclerosis.
文摘Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.
文摘Assessment of entrance skin doses for patients in Digital radiography examinations should be made as a means for the optimization of the radiation protection of the patients. We measured the entrance skin dose (ESD) received by 50 pediatrics undergoing 12 types of diagnostic X-ray examination at Radiology Department of Asser Central Hospital-KSA. The entrance skin dose ESD was determined via measurements parameters: focus to skin distance (FSD), tube current (mAs) and tube voltage (kV) in arithmetical equation. The mean ± SD for ESDs were found to be 0.16 ± 0.03, 0.21 ± 0.01, 0.63 ± 0.26, 0.55 ± 0.09, 0.15 ± 0.05, 0.27 ± 0.06, 0.41 ± 0.19, 0.46 ± 0.18, 0.46 ± 0.12, 0.20 ± 0.02, 0.39 ± 0.01, 0.29 ± 0.03, for PA chest, foot, AP pelvis, PA skull, PA hand, AP arm, ankle, AP shoulder, abdomen, forearm, AP femur, AP elbow consequently. Our study is considered as an attempt to evaluate the ESDs received by digital radiographic x-ray machine for children aged between 2 - 15 years old, taking in our considerations number of other variables. The mean ESD values obtained are found to be within the standard reference. The data obtained may add to the available information in national records for general use. It may provide guidance on where efforts on dose reduction will need to be directed to fulfill the requirements of the optimization process and serve as a reference for future researches.
基金the National Science Foundation of China(Grant Nos.41871233,41371330 , 41001203).
文摘Background:Digital hemispherical photography(DHP)is widely used to estimate the leaf area index(LAI)of forest plots due to its advantages of high efficiency and low cost.A crucial step in the LAI estimation of forest plots via DHP is choosing a sampling scheme.However,various sampling schemes involving DHP have been used for the LAI estimation of forest plots.To date,the impact of sampling schemes on LAI estimation from DHP has not been comprehensively investigated.Methods:In this study,13 commonly used sampling schemes which belong to five sampling types(i.e.dispersed,square,cross,transect and circle)were adopted in the LAI estimation of five Larix principis-rupprechtii plots(25m×25 m).An additional sampling scheme(with a sample size of 89)was generated on the basis of all the sample points of the 13 sampling schemes.Three typical inversion models and four canopy element clumping index(Ωe)algorithms were involved in the LAI estimation.The impacts of the sampling schemes on four variables,including gap fraction,Ωe,effective plant area index(PAIe)and LAI estimation from DHP were analysed.The LAI estimates obtained with different sampling schemes were then compared with those obtained from litter collection measurements.Results:Large differences were observed for all four variable estimates(i.e.gap fraction,Ωe,PAIe and LAI)under different sampling schemes.The differences in impact of sampling schemes on LAI estimation were not obvious for the three inversion models,if the fourΩe algorithms,except for the traditional gap-size analysis algorithm were adopted in the estimation.The accuracy of LAI estimation was not always improved with an increase in sample size.Moreover,results indicated that with the appropriate inversion model,Ωe algorithm and sampling scheme,the maximum estimation error of DHP-estimated LAI at elementary sampling unit can be less than 20%,which is required by the global climate observing system,except in forest plots with extremely large LAI values(~>6.0).However,obtaining an LAI from DHP with an estimation error lower than 5%is impossible regardless of which combination of inversion model,Ωe algorithm and sampling scheme is used.Conclusion:The LAI estimation of L.principis-rupprechtii forests from DHP was largely affected by the sampling schemes adopted in the estimation.Thus,the sampling scheme should be seriously considered in the LAI estimation.One square and two transect sampling schemes(with sample sizes ranging from 3 to 9)were recommended to be used to estimate the LAI of L.principis-rupprechtii forests with the smallest mean relative error(MRE).By contrast,three cross and one dispersed sampling schemes were identified to provide LAI estimates with relatively large MREs.
文摘Rheumatoid arthritis is a chronic multisystem disease of unknown cause. The characteristic feature of RA is persistent inflammatory synovitis. The natural history of disease is such that the early months of the disease are critical period during which reversible joint damage occurs. So early diagnosis of RA and appropriate drug application is the only way to save a patient from this crippling disease. In India, the cost of investigations is a significant factor for most of the patients. Ultrasonography or Power Doppler Ultra Sound (PDUS) has the advantage of being economic in spite of its sensitivity in assessing both inflammatory and destructive changes. The aim of the present study was to evaluate the diagnostic efficiency of PDUS in early rheumatoid arthritis. The study was performed with the patients attending Rheumatology Clinic. A total number of 106 patients of clinically suspected rheumatoid arthritis were studied as per selection criteria. Radiological examinations of hands were done by digital radiography and PDUS in a group of 53 patients, assessment of foot changes by PDUS and Digital Radiography were done in another similar group of 53 patients. Final diagnosis by ACR EULAR-2010 criteria is done for all the patients. The comparative study reveals that synovial vascularity as demonstrated by PDUS is much more effective in diagnosing early rheumatoid arthritis, both in hand and in feet than digital radiograph. PDUS of feet may yield earlier and better findings than hands, which is conventionally used in patients suffering from early rheumatoid arthritis.
文摘In the following work of research, we shall present the results of a study on forms of digital photographic socialization as carried out by the so-called "digital natives" in order to explore their competence in managing digital photographic output and cultural practices. This shall be done under the following categories of analysis: snapshot, organization, socialization, reception, privacy, and copyrights in digital photography. The study explores the forms of digital photography production, technical problems of photographic management and the final uses that digital photographers give to their photos in terms of web tools 2.0, mobile telephones and social networks. Digital photography technology, compact cameras, mobile phones with cameras, specialized websites in photography and the lnternet generate new forms of production and emerging styles of digital photographic socialization. The study is carried out using a defined sample of university students, those digital natives who create and use digital photography.
文摘In aerial photography, the primary factor is terrain undulation. However, most of the external aerial photography software used for aerial photography design do not take terrain undulation influence into consideration. Therefore, the design result has comparative randomicity and "gaps" are expected. An aerial photography design system is developed by analyzing the terrain undulation influence to the design result with DEM data so that the forward overlap and side overlap can be justified according to the block terrain undulation to meet specifications or standards. The data designed by this system is compared with the real flying data. The results show that making use of DEM to assist in aerial photography design can ensure that the designed result fits the real terrain better.
文摘Two speckle patterns are recorded using a video cameracorresponding to undisplaced and displaced states into the memory ofa computer. After one pattern is added to another, the displacementof the measured points can be calculated by using the Fouriertransform. The expression of displacement field is deduced fornon-uniform displacement, and as an example, a rotatanle disc istested for illustration. The re- sults prove that the present methodis promising.