This study attempted to interpret differential item discriminations between individual and cluster levels by focusing on patterns and magnitudes of item discriminations under 2PL multilevel IRT model through a set of ...This study attempted to interpret differential item discriminations between individual and cluster levels by focusing on patterns and magnitudes of item discriminations under 2PL multilevel IRT model through a set of variety simulation conditions. The consistency between the mean of individual-level ability estimates and cluster-level ability estimates was evaluated by the correlations between them. As a result, it was found that they were highly correlated if the patterns of item discriminations were the same for both individual and cluster levels. The magnitudes of item discriminations themselves did not affect much on correlations, as far as the patterns were the same at the two levels. However, it was found that the correlation became lower when the patterns of item discriminations were different between the individual and cluster levels. Also, it was revealed that the mean of the estimated individual-level abilities would not be necessarily a good representation of the cluster-level ability, if the patterns were different at the two levels.展开更多
M/C test is always an essential means of testing for language teachers.However,we have every reason to doubt whether a randomly designed M/C test could effectively reflect the testees' language standard.In most la...M/C test is always an essential means of testing for language teachers.However,we have every reason to doubt whether a randomly designed M/C test could effectively reflect the testees' language standard.In most language testing,before the actual writing of a test paper,we should first analyze the items to see whether they're good or qualified enough to be put into the test paper or to be included in the item bank for further use because it is only through item analysis that we can make the test paper more scientific.Based on this theory,there 're some principles we should follow when writing or assessing M/C tests.展开更多
Ultrasonic guided wave have the multi-modes and dispersive characteristics, and its modes are easy to be converted at boundary or when running into defects in pipes, which makes the discrimination of different guided ...Ultrasonic guided wave have the multi-modes and dispersive characteristics, and its modes are easy to be converted at boundary or when running into defects in pipes, which makes the discrimination of different guided waves modes of the reflection signals in pipes NDT very hard. In this work, firstly, the experiments are carried out to test two kinds of stainless steel pipes by applying guided waves NDT, one is integrated pipe and another is non-integrated pipe with a small hole defect, and the detected guided waves echo signals are respectively obtained. Secondly, the measured signals are processed by matching pursuit method and the Chirplet matching atom parameters are calculated. By calculating the time-frequency distributions spectrum of detected guided waves echo signals, torsional, flexural and longitudinal guided waves modes are identified from the intact pipe, and the two wave-packets with torsional and flexural guided waves modes are also identified from the pipe with hole defect. The results showed that the matching pursuit method has a tremendous advantage to identify different guided waves modes in pipes nondestructive testing.展开更多
This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during e...This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during examinees prior testing. Disadvantage of the mentioned item calibration method is the item exposure; when test items become familiar to the examinees. To reduce the item exposure, automatic item generation method is used, where item models are being constructed based on already calibrated test items without losing already estimated item parameters. A technic of item model extraction method from the already calibrated and therefore exposed test items described, which can be used by the test item development specialists to integrate automatic item generation principles with the existing testing applications.展开更多
A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom's revised taxonomy and s...A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom's revised taxonomy and scale anchoring respectively to produce the characteristics for test items. A smoothing method of arbitrary anchoring revised from scale anchoring is first proposed to make tests more accurate in distinguishing test levels. In addition, raised three dimensional indicators based on the Bloom's revised taxonomy are adopted to validate test contents and therefore it concretely describes the examining function of items. The items obtained have the precise and concrete properties; an item knowledge library is therefore constructed combining teaching materials and items using the technologies of ontology and knowledge management. Finally, a knowledge library system of test items is established to achieve the purpose of adaptive learning for learners.展开更多
Testing is a universal feature of social life.Throughout history people have been put to the test to prove their capabilities or to establish qualifications.Language tests play an important role in many people's l...Testing is a universal feature of social life.Throughout history people have been put to the test to prove their capabilities or to establish qualifications.Language tests play an important role in many people's lives,acting as gateways at important transitional moments in education.The college English test paper was reviewed and checked against the test specifications to see its content coverage and representative.To evaluate the test,this includes item analysis,descriptive statistics,validity,and what we see as the strong points and the weaknesses of the test based on the analysis and the testing conditions,both of which provided validity evidence.In order to gather details of the test items,item analysis was done to find out the difficulty and discrimination of each item and identify misfit items for further discussion.展开更多
AIM: To verify the usefulness of FibroQ for predicting fi brosis in patients with chronic hepatitis C, compared with other noninvasive tests. METHODS: This retrospective cohort study included 237 consecutive patients ...AIM: To verify the usefulness of FibroQ for predicting fi brosis in patients with chronic hepatitis C, compared with other noninvasive tests. METHODS: This retrospective cohort study included 237 consecutive patients with chronic hepatitis C who had undergone percutaneous liver biopsy before treatment. FibroQ, aspartate aminotransferase (AST)/alanine aminotransferase ratio (AAR), AST to platelet ratioindex, cirrhosis discriminant score, age-platelet index (API), Pohl score, FIB-4 index, and Lok's model were calculated and compared. RESULTS: FibroQ, FIB-4, AAR, API and Lok's model results increased significantly as fibrosis advanced (analysis of variance test: P < 0.001). FibroQ trended to be superior in predicting signifi cant fi brosis score in chronic hepatitis C compared with other noninvasive tests. CONCLUSION: FibroQ is a simple and useful test for predicting signifi cant fi brosis in patients with chronic hepatitis C.展开更多
Face recognition has been widely used and developed rapidly in recent years.The methods based on sparse representation have made great breakthroughs,and collaborative representation-based classification(CRC)is the typ...Face recognition has been widely used and developed rapidly in recent years.The methods based on sparse representation have made great breakthroughs,and collaborative representation-based classification(CRC)is the typical representative.However,CRC cannot distinguish similar samples well,leading to a wrong classification easily.As an improved method based on CRC,the two-phase test sample sparse representation(TPTSSR)removes the samples that make little contribution to the representation of the testing sample.Nevertheless,only one removal is not sufficient,since some useless samples may still be retained,along with some useful samples maybe being removed randomly.In this work,a novel classifier,called discriminative sparse parameter(DSP)classifier with iterative removal,is proposed for face recognition.The proposed DSP classifier utilizes sparse parameter to measure the representation ability of training samples straight-forward.Moreover,to avoid some useful samples being removed randomly with only one removal,DSP classifier removes most uncorrelated samples gradually with iterations.Extensive experiments on different typical poses,expressions and noisy face datasets are conducted to assess the performance of the proposed DSP classifier.The experimental results demonstrate that DSP classifier achieves a better recognition rate than the well-known SRC,CRC,RRC,RCR,SRMVS,RFSR and TPTSSR classifiers for face recognition in various situations.展开更多
The College English Test Band Six(CET-6)is one of the most widely applied exam across China.As a national teaching test,CET-6 is sponsored by the Department of higher education of the Ministry of education of The Peo...The College English Test Band Six(CET-6)is one of the most widely applied exam across China.As a national teaching test,CET-6 is sponsored by the Department of higher education of the Ministry of education of The People’s Republic of China and held twice a year.In this study,77 sophomores of different majors were tested using the listening test in June 2018.It is ensured that the test method is exactly same as that of CET-6.The purpose of this paper is to analyze the content and specification of CET-6 listening comprehension test,and to evaluate this part in detail according to the real data,including score report and item analysis,trying to provide some enlightenment for the revision of the examination.展开更多
This paper proposes a novel approach for the automatic detection of allergy test (allergy lesion). A hyperspectral microscope system was used to image the test samples which were diagnosed by dermatologist. It was fou...This paper proposes a novel approach for the automatic detection of allergy test (allergy lesion). A hyperspectral microscope system was used to image the test samples which were diagnosed by dermatologist. It was found that allergy of different levels, and healthy skin cells show absorption spectra, which are sufficiently characteristic and yet reproducible enough to allow for differentiation when using a spectroscopic system. Principal components analysis was used to extract relevant features that could be used for classification from these spectra. Preliminary results indicate that the different types of allergy cells can be reliably distinguished by these features. We conclude that hyperspectral microscopic analysis is a promising approach for improving and automating the diagnosis of allergy test as well as another skin lesions.展开更多
It is quite necessary for teachers of English to know the basic knowledge and techniques about how to design good English testpapers. To meet this necessity, this paper first tells of the basic principles and requirem...It is quite necessary for teachers of English to know the basic knowledge and techniques about how to design good English testpapers. To meet this necessity, this paper first tells of the basic principles and requirements of designing English test papers, then the procedures,and, at last, the characters of some test questions and the techniques when designing them.展开更多
文摘This study attempted to interpret differential item discriminations between individual and cluster levels by focusing on patterns and magnitudes of item discriminations under 2PL multilevel IRT model through a set of variety simulation conditions. The consistency between the mean of individual-level ability estimates and cluster-level ability estimates was evaluated by the correlations between them. As a result, it was found that they were highly correlated if the patterns of item discriminations were the same for both individual and cluster levels. The magnitudes of item discriminations themselves did not affect much on correlations, as far as the patterns were the same at the two levels. However, it was found that the correlation became lower when the patterns of item discriminations were different between the individual and cluster levels. Also, it was revealed that the mean of the estimated individual-level abilities would not be necessarily a good representation of the cluster-level ability, if the patterns were different at the two levels.
文摘M/C test is always an essential means of testing for language teachers.However,we have every reason to doubt whether a randomly designed M/C test could effectively reflect the testees' language standard.In most language testing,before the actual writing of a test paper,we should first analyze the items to see whether they're good or qualified enough to be put into the test paper or to be included in the item bank for further use because it is only through item analysis that we can make the test paper more scientific.Based on this theory,there 're some principles we should follow when writing or assessing M/C tests.
文摘Ultrasonic guided wave have the multi-modes and dispersive characteristics, and its modes are easy to be converted at boundary or when running into defects in pipes, which makes the discrimination of different guided waves modes of the reflection signals in pipes NDT very hard. In this work, firstly, the experiments are carried out to test two kinds of stainless steel pipes by applying guided waves NDT, one is integrated pipe and another is non-integrated pipe with a small hole defect, and the detected guided waves echo signals are respectively obtained. Secondly, the measured signals are processed by matching pursuit method and the Chirplet matching atom parameters are calculated. By calculating the time-frequency distributions spectrum of detected guided waves echo signals, torsional, flexural and longitudinal guided waves modes are identified from the intact pipe, and the two wave-packets with torsional and flexural guided waves modes are also identified from the pipe with hole defect. The results showed that the matching pursuit method has a tremendous advantage to identify different guided waves modes in pipes nondestructive testing.
文摘This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during examinees prior testing. Disadvantage of the mentioned item calibration method is the item exposure; when test items become familiar to the examinees. To reduce the item exposure, automatic item generation method is used, where item models are being constructed based on already calibrated test items without losing already estimated item parameters. A technic of item model extraction method from the already calibrated and therefore exposed test items described, which can be used by the test item development specialists to integrate automatic item generation principles with the existing testing applications.
文摘A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom's revised taxonomy and scale anchoring respectively to produce the characteristics for test items. A smoothing method of arbitrary anchoring revised from scale anchoring is first proposed to make tests more accurate in distinguishing test levels. In addition, raised three dimensional indicators based on the Bloom's revised taxonomy are adopted to validate test contents and therefore it concretely describes the examining function of items. The items obtained have the precise and concrete properties; an item knowledge library is therefore constructed combining teaching materials and items using the technologies of ontology and knowledge management. Finally, a knowledge library system of test items is established to achieve the purpose of adaptive learning for learners.
文摘Testing is a universal feature of social life.Throughout history people have been put to the test to prove their capabilities or to establish qualifications.Language tests play an important role in many people's lives,acting as gateways at important transitional moments in education.The college English test paper was reviewed and checked against the test specifications to see its content coverage and representative.To evaluate the test,this includes item analysis,descriptive statistics,validity,and what we see as the strong points and the weaknesses of the test based on the analysis and the testing conditions,both of which provided validity evidence.In order to gather details of the test items,item analysis was done to find out the difficulty and discrimination of each item and identify misfit items for further discussion.
基金Supported by Clinical Study Project XMRP, No. CMRPG 690081, from Chiayi Chang Gung Memorial Hospital
文摘AIM: To verify the usefulness of FibroQ for predicting fi brosis in patients with chronic hepatitis C, compared with other noninvasive tests. METHODS: This retrospective cohort study included 237 consecutive patients with chronic hepatitis C who had undergone percutaneous liver biopsy before treatment. FibroQ, aspartate aminotransferase (AST)/alanine aminotransferase ratio (AAR), AST to platelet ratioindex, cirrhosis discriminant score, age-platelet index (API), Pohl score, FIB-4 index, and Lok's model were calculated and compared. RESULTS: FibroQ, FIB-4, AAR, API and Lok's model results increased significantly as fibrosis advanced (analysis of variance test: P < 0.001). FibroQ trended to be superior in predicting signifi cant fi brosis score in chronic hepatitis C compared with other noninvasive tests. CONCLUSION: FibroQ is a simple and useful test for predicting signifi cant fi brosis in patients with chronic hepatitis C.
基金Project(2019JJ40047)supported by the Hunan Provincial Natural Science Foundation of ChinaProject(kq2014057)supported by the Changsha Municipal Natural Science Foundation,China。
文摘Face recognition has been widely used and developed rapidly in recent years.The methods based on sparse representation have made great breakthroughs,and collaborative representation-based classification(CRC)is the typical representative.However,CRC cannot distinguish similar samples well,leading to a wrong classification easily.As an improved method based on CRC,the two-phase test sample sparse representation(TPTSSR)removes the samples that make little contribution to the representation of the testing sample.Nevertheless,only one removal is not sufficient,since some useless samples may still be retained,along with some useful samples maybe being removed randomly.In this work,a novel classifier,called discriminative sparse parameter(DSP)classifier with iterative removal,is proposed for face recognition.The proposed DSP classifier utilizes sparse parameter to measure the representation ability of training samples straight-forward.Moreover,to avoid some useful samples being removed randomly with only one removal,DSP classifier removes most uncorrelated samples gradually with iterations.Extensive experiments on different typical poses,expressions and noisy face datasets are conducted to assess the performance of the proposed DSP classifier.The experimental results demonstrate that DSP classifier achieves a better recognition rate than the well-known SRC,CRC,RRC,RCR,SRMVS,RFSR and TPTSSR classifiers for face recognition in various situations.
文摘The College English Test Band Six(CET-6)is one of the most widely applied exam across China.As a national teaching test,CET-6 is sponsored by the Department of higher education of the Ministry of education of The People’s Republic of China and held twice a year.In this study,77 sophomores of different majors were tested using the listening test in June 2018.It is ensured that the test method is exactly same as that of CET-6.The purpose of this paper is to analyze the content and specification of CET-6 listening comprehension test,and to evaluate this part in detail according to the real data,including score report and item analysis,trying to provide some enlightenment for the revision of the examination.
文摘This paper proposes a novel approach for the automatic detection of allergy test (allergy lesion). A hyperspectral microscope system was used to image the test samples which were diagnosed by dermatologist. It was found that allergy of different levels, and healthy skin cells show absorption spectra, which are sufficiently characteristic and yet reproducible enough to allow for differentiation when using a spectroscopic system. Principal components analysis was used to extract relevant features that could be used for classification from these spectra. Preliminary results indicate that the different types of allergy cells can be reliably distinguished by these features. We conclude that hyperspectral microscopic analysis is a promising approach for improving and automating the diagnosis of allergy test as well as another skin lesions.
文摘It is quite necessary for teachers of English to know the basic knowledge and techniques about how to design good English testpapers. To meet this necessity, this paper first tells of the basic principles and requirements of designing English test papers, then the procedures,and, at last, the characters of some test questions and the techniques when designing them.