The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction ...The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.展开更多
一、单项选择题(25%) Read the following unfinished statements or ques-tions carefully. For each unfinished statement or ques-tion four suggested answers A, B, C and D are given.Choose the one you think best completes ...一、单项选择题(25%) Read the following unfinished statements or ques-tions carefully. For each unfinished statement or ques-tion four suggested answers A, B, C and D are given.Choose the one you think best completes the statementor answers the question:1.The British Empire gradually disappeared and it was replaced by the____.展开更多
四、名词解释(15%)Explain the following terms in English:1.Jazz 2.Fianna Fail3.Counterculture 4.The Privy Council5.“Quiet Revolution”五、简答题(12%)Give brief answers to the following questions;1.What do you know abo...四、名词解释(15%)Explain the following terms in English:1.Jazz 2.Fianna Fail3.Counterculture 4.The Privy Council5.“Quiet Revolution”五、简答题(12%)Give brief answers to the following questions;1.What do you know about the“public schools”in the UK?2.What are the powers of the U.S.President?3.What is meant bv the term“welfare state”inBritain?展开更多
This paper, comparison of two sample tests, is motivated by the fact that in the test of significant difference between two independent samples, numerous methods can be adopted;each may lead to significant different r...This paper, comparison of two sample tests, is motivated by the fact that in the test of significant difference between two independent samples, numerous methods can be adopted;each may lead to significant different results;this implies that wrong choice of test statistic could lead to erroneous conclusion. To prevent misleading information, there is a need for proper investigation of some selected methods for test of significant difference between variables/subjects most especially, independent samples. The paper examines the efficiency and sensitivity of four test statistics to ascertain which test performs better. Based on the results, the relative efficiency favours median test as being more efficient than modified median test for both symmetric and asymmetric distributions. In terms of power of test, median test is more sensitive than Modified Median (MMED) test since it has higher power irrespective of the sample sizes for both symmetric and asymmetric distribution. In terms of relative efficiency for asymmetric distribution Modified Mann-Whitney U test is more efficient than Mann-Whitney U test (MMWU), and then for symmetric distribution, Mann-Whitney U test (MMWU) is more efficient than Modified Mann-Whitney in sample size of 5;but for other sample sizes considered Modified Mann-Whitney U test (MMWU) is better than Mann-Whitney. Using power of test for both symmetric and asymmetric distributions, Mann-Whitney is more sensitive than Modified Mann-Whitney U test (MMWU) because it has higher power.展开更多
Unwanted sound that is unpleasant or disruptive to hear, often interpreted as noise, is a widespread environmental pollutant. Similar to other environmental pollutants, this noise incurs a variety of costs to society....Unwanted sound that is unpleasant or disruptive to hear, often interpreted as noise, is a widespread environmental pollutant. Similar to other environmental pollutants, this noise incurs a variety of costs to society. Numerous negative health impacts are linked to increases in noise exposure,such as increased cardiovascular risk;and sleep展开更多
[Objectives]To reduce suicidal ideation and suicidal behavior through initial screening of patients with suicidal tendencies and implementing suicide prevention interventions during their hospitalization.[Methods]The ...[Objectives]To reduce suicidal ideation and suicidal behavior through initial screening of patients with suicidal tendencies and implementing suicide prevention interventions during their hospitalization.[Methods]The Taihe Emotion-distress Index(THEI)was used to conduct pre-admission and post-discharge tests to explore the effects of suicide prevention measures during hospitalization on the alleviation of the disease and the reduction of suicidal behaviors.The study selected patients who were diagnosed with depression in the psychological outpatient department of Taihe Hospital from April 2019 to September 2019 and had to be hospitalized,including patients with moderate depressive episodes,severe depressive episodes with or without psychotic symptoms,and patients with suicidal thoughts and self-harming behaviors.[Results]The pre-admission and post-discharge test data of hospitalized patients were analyzed,and the non-parametric paired sample T test was carried out,and the result was P<0.05,showing that there are significant differences between the pre-admission and post-discharge test data.[Conclusions]The measures of suicide prevention intervention are effective to a certain extent.展开更多
This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. ...This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. A code is developed for the criteria check and the sample ship calculations show that the accuracy of the wave surge force estimation has a significant influence on the assessment result. For further investigation, the wave surge force measurement through a captive model test is made for a purse seiner to validate the numerical model, the effects of the wave steepness and the ship forward speed on the wave surge force responses are also discussed. It is demonstrated that the diffraction effect is important for the correct estimation of the wave surge force. Therefore, it is recommended to include this effect in the assessment procedure.展开更多
基金the National Natural Science Foundation of China(Grant No.61973033)Preliminary Research of Equipment(Grant No.9090102010305)for funding the experiments。
文摘The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.
文摘一、单项选择题(25%) Read the following unfinished statements or ques-tions carefully. For each unfinished statement or ques-tion four suggested answers A, B, C and D are given.Choose the one you think best completes the statementor answers the question:1.The British Empire gradually disappeared and it was replaced by the____.
文摘四、名词解释(15%)Explain the following terms in English:1.Jazz 2.Fianna Fail3.Counterculture 4.The Privy Council5.“Quiet Revolution”五、简答题(12%)Give brief answers to the following questions;1.What do you know about the“public schools”in the UK?2.What are the powers of the U.S.President?3.What is meant bv the term“welfare state”inBritain?
文摘This paper, comparison of two sample tests, is motivated by the fact that in the test of significant difference between two independent samples, numerous methods can be adopted;each may lead to significant different results;this implies that wrong choice of test statistic could lead to erroneous conclusion. To prevent misleading information, there is a need for proper investigation of some selected methods for test of significant difference between variables/subjects most especially, independent samples. The paper examines the efficiency and sensitivity of four test statistics to ascertain which test performs better. Based on the results, the relative efficiency favours median test as being more efficient than modified median test for both symmetric and asymmetric distributions. In terms of power of test, median test is more sensitive than Modified Median (MMED) test since it has higher power irrespective of the sample sizes for both symmetric and asymmetric distribution. In terms of relative efficiency for asymmetric distribution Modified Mann-Whitney U test is more efficient than Mann-Whitney U test (MMWU), and then for symmetric distribution, Mann-Whitney U test (MMWU) is more efficient than Modified Mann-Whitney in sample size of 5;but for other sample sizes considered Modified Mann-Whitney U test (MMWU) is better than Mann-Whitney. Using power of test for both symmetric and asymmetric distributions, Mann-Whitney is more sensitive than Modified Mann-Whitney U test (MMWU) because it has higher power.
基金sponsored by the projects with OSP#193942 and#193940
文摘Unwanted sound that is unpleasant or disruptive to hear, often interpreted as noise, is a widespread environmental pollutant. Similar to other environmental pollutants, this noise incurs a variety of costs to society. Numerous negative health impacts are linked to increases in noise exposure,such as increased cardiovascular risk;and sleep
文摘[Objectives]To reduce suicidal ideation and suicidal behavior through initial screening of patients with suicidal tendencies and implementing suicide prevention interventions during their hospitalization.[Methods]The Taihe Emotion-distress Index(THEI)was used to conduct pre-admission and post-discharge tests to explore the effects of suicide prevention measures during hospitalization on the alleviation of the disease and the reduction of suicidal behaviors.The study selected patients who were diagnosed with depression in the psychological outpatient department of Taihe Hospital from April 2019 to September 2019 and had to be hospitalized,including patients with moderate depressive episodes,severe depressive episodes with or without psychotic symptoms,and patients with suicidal thoughts and self-harming behaviors.[Results]The pre-admission and post-discharge test data of hospitalized patients were analyzed,and the non-parametric paired sample T test was carried out,and the result was P<0.05,showing that there are significant differences between the pre-admission and post-discharge test data.[Conclusions]The measures of suicide prevention intervention are effective to a certain extent.
基金Project supported by the High-Technology Ship Research Project of Ministry of Industry and Information Technology(Grant No.K24352)the National Natural Science Foundation of China(973 Praogram,Grant No.51579144)
文摘This study focuses on the influence of the wave surge force on the assessments of the surf-riding/broaching vulnerability criteria according to the new proposal of the IMO Second Generation Intact Stability Criteria. A code is developed for the criteria check and the sample ship calculations show that the accuracy of the wave surge force estimation has a significant influence on the assessment result. For further investigation, the wave surge force measurement through a captive model test is made for a purse seiner to validate the numerical model, the effects of the wave steepness and the ship forward speed on the wave surge force responses are also discussed. It is demonstrated that the diffraction effect is important for the correct estimation of the wave surge force. Therefore, it is recommended to include this effect in the assessment procedure.