在AutoCAD中用图标菜单方式建立制图试题库

制图课的特点就是图多,测验题或考试题一般也是以图形为主.这样,出卷子的工作量就非常大,一份卷子全部用手工绘制,所化时间很多.如用剪贴的方式,则卷子很不雅观,缺乏规范效应.AutoCAD绘图软件,是一个开放型软件,使用者可对其进行二次开发,使之为某一特殊用途服务,通过对菜单文件的开发,在计算机内建立起树形结构的同形试题库.可大大减轻教师的工作量,并且使试卷规范化.

语义激活:开启大学生英语说写思路的策略

语言认知的多重维度——词汇网络和语义网络、图式和情景框、语义激活理论即以语义为联想点的词汇积聚、列锦式的主题联想、预读复述和添加图式概念 。

国有企业职工士气水平的调查与分析

员工士气水平的高低 ,从某种程度上决定企业是否成功的关键。如何调动员工的积极性和主动性成为各级企业尤其是国有企业比较棘手的问题。职工士气水平的高低取决于多种因素 ,本文从管理方式、领导行为、工作内容和作业条件、工作气氛及心理压力五个主要方面对部分国有企业进行调查分析 ,用百分点诊断图标志出来 ,以便观测职工的士气水平 ,供有关人士参考。

关于若干整数分拆问题(英文)

Y.Alavi,A.J.Boals,G.Chartrand,P.Erds和O.R.Oellermann提出下面的猜想:已知整数a1,a2,…,ak,满足n≤ai≤2n-2,1≤i≤k,且a1+a2+…+ak=n(n+1)/2,则S={1,2,…,n}包含有k个互不相交子集S1,S2,…,Sk,满足ai=Σ(Si),1≤i≤k。推广该猜想,得到下面的定理:已知整数a1,a2,…,ak,满足ai≥n,1≤i≤k,且a1+a2+…+ak≤n(n+1)/2,则S={1,2,…,n}包含有k个互不相交子集S1,S2,…,Sk,满足ai=Σ(Si),1≤i≤k。由此定理易推出K.Ando,S.Gervacio和M.Kano证明的一个主要定理。参考文献中的一个错误同时被更正。

例谈学生创新思维的培养

本文运用守恒原理、图式分析法和层次问题质难解凝的观点 ,结合数例比较深入地探讨了在中学化学教学中培养学生创新意识。

Research on technological parameters of pressure forming with hot granule medium on AA7075 sheet

Hot granule medium pressure forming （HGMF） process is a new process in which granule medium replaces the medium in existing flexible-die hot forming process, such as liquids, gases or viscous medium. Hot forming of light alloy sheet parts can be realized based on the properties of granule medium, such as withstanding high temperature and pressure, filling well, sealing and loading easily. In this work, the forming of AA7075 cylindrical parts by HGMF process is taken as an example to establish the constitutive relation and forming limit diagram （FLD） of AA7075 sheet which is related to temperature by hot uniaxial tensile test of sheet metal. Based on the assumption that granule medium is applied to extended Drucker-Prager linear material model, the finite element model of HGMF process is established and the effect of technological parameters, such as forming temperature, blank-holder gap and drawing ratio, on the sheet metal formability, is studied. The limit drawing ratio curve of AA7075 cylindrical parts at forming temperature of 175-300 ℃ is obtained by HGMF process test, and the limit drawing ratio reaches the maximum value of 1.71 at 250 ℃. The results of numerical simulation are consistent with the results of process test, and the forming force, distribution of wall thichness and form of instability are predicted correctly, which provides reference for the application of HGMF process.

Method for test case selection and execution of web application regression testing

In order to improve the efficiency of regression testing in web application,the control flow graph and the greedy algorithm are adopted.This paper considers a web page as a basic unit and introduces a test case selection method for web application regression testing based on the control flow graph.This method is safe enough to the test case selection.On the base of features of request sequence in web application,the minimization technique and the priority of test cases are taken into consideration in the process of execution of test cases in regression testing for web application.The improved greedy algorithm is also raised resulting in optimization of execution of test cases.The experiments indicate that the number of test cases which need to be retested is reduced,and the efficiency of execution of test cases is also improved.

Study on EEG power and coherence in patients with mild cognitive impairment during working memory task

To investigate the features of electroencephalography （EEG） power and coherence at rest and during a working memory task of patients with mild cognitive impairment （MCI）. Thirty-five patients （17 males, 18 females; 52-71 years old） and 34 sex- and age-matched controls （17 males, 17 females; 51-63 years old） were recruited in the present study. Mini-Mental State Examination （MMSE） of 35 patients with MCI and 34 normal controls revealed that the scores of MCI patients did not differ significantly from those of normal controls （P〉0.05）. Then, EEGs at rest and during working memory task with three levels of working memory load were recorded. The EEG power was computed over 10 channels： fight and left frontal （F3, F4）, central （C3, C4）, parietal （P3, P4）, temporal （T5, T6） and occipital （O1, O2）; inter-hemispheric coherences were computed from five electrode pairs of F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 for delta （1.0-3.5 Hz）, theta （4.0-7.5 Hz）, alpha-1 （8.0-10.0 Hz）, alpha-2 （10.5-13.0 Hz）, beta-1 （13.5-18.0 Hz） and beta-2 （18.5-30.0 Hz） frequency bands. All values of the EEG power of MCI patients were found to be higher than those of normal controls at rest and during working memory tasks. Furthermore, the values of EEG power in the theta, alpha-1, alpha-2 and beta-1 bands of patients with MCI were significantly high （P〈0.05） in comparison with those of normal controls. Correlation analysis indicated a significant negative correlation between the EEG powers and MMSE scores. In addition, during working memory tasks, the EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group （P〈0.05）. However, there was no significant difference in EEG coherences between two groups at rest. These findings comprise evidence that MCI patients have higher EEG power at rest, and higher EEG power and coherence during working conditions. It suggests that MCI may be associated with compensatory processes at rest and during working memory tasks. Moreover, failure of normal cortical connections may be exist in MCI patients.

A Coordinate Gradient Descent Method for Nonsmooth Nonseparable Minimization

This paper presents a coordinate gradient descent approach for minimizing the sum of a smooth function and a nonseparable convex function.We find a search direction by solving a subproblem obtained by a second-order approximation of the smooth function and adding a separable convex function.Under a local Lipschitzian error bound assumption,we show that the algorithm possesses global and local linear convergence properties.We also give some numerical tests(including image recovery examples) to illustrate the efficiency of the proposed method.

Strain field investigation of limestone specimen under uniaxial compression loads using particle image velocimetry

The particle image velocimetry (PIV) method was used to investigate the full-field displacements and strains of the limestone specimen under external loads from the video images captured during the laboratory tests.The original colorful video images and experimental data were obtained from the uniaxial compression test of a limestone.To eliminate perspective errors and lens distortion,the camera was placed normal to the rock specimen exposure.After converted into a readable format of frame images,these videos were transformed into the responding grayscale images,and the frame images were then extracted.The full-field displacement field was obtained by using the PIV technique,and interpolated in the sub-pixel locations.The displacement was measured in the plane of the image and inferred from two consecutive images.The local displacement vectors were calculated for small sub-windows of the images by means of cross-correlation.The video images were interrogated in a multi-pass way,starting off with 64×64 images,ending with 16×16 images after 6 iterations,and using 75% overlap of the sub-windows.In order to remove spurious vectors,the displacements were filtered using four filters:signal-to-noise ratio filter,peak height filter,global filter and local filter.The cubic interpolation was utilized if the displacements without a number were encountered.The full-field strain was then obtained using the local least square method from the discrete displacements.The strain change with time at different locations was also investigated.It is found that the normal strains are dependant on the locations and the crack distributions.Between 1.0 and 5.0 s prior to the specimen failure,normal strains increase rapidly at many locations,while a stable status appears at some locations.When the specimen is in a failure status,a large rotation occurs and it increases in the inverse direction.The strain concentration bands do not completely develop into the large cracks,and meso-cracks are not visible in some bands.The techniques presented here may improve the traditional measurement of the strain field,and may provide a lot of valuable information in investigating the deformation/failure mechanism of rock materials.

Processing map and microstructure evaluation of AA6061/Al_2O_3 nanocomposite at different temperatures

Hot compression behavior of Al6061/Al2O3nanocomposite was investigated in the temperature range of350-500°C andthe strain rate range of0.0005-0.5s-1,in order to determine the optimum conditions for the hot workability of nanocomposite.Theactivation energy of285kJ/mol for the hot compression test is obtained by using hyperbolic sine function.By means of dynamicmaterial model(DMM)and the corresponding processing map,safe zone for the hot workability of AA6061/Al2O3is recognized attemperature of450°C and strain rate of0.0005s-1and at temperature of500°C and the strain rate range of0.0005-0.5s-1,with themaximum power dissipation efficiency of38%.Elongated and kinked grains are observed at400°C and strain rate of0.5s-1due tothe severe deformation.

Cardiac metastasis from colorectal cancer:A case report

The heart is an unusual site of metastasis from any malignancy. We report a case of cardiac metastasis from colorectal cancer. A 70-year-old woman was referred with a presumptive diagnosis of sigmoid colon cancer with cardiac myxoma. Two-dimensional echocardiography showed a 4 cm x 4.5 cm mobile mass on the lateral right atrial wall, and computed tomography revealed a low attenuated Iobulating mass in the right atrium. The patient underwent anterior resection for sigmoid colon cancer （T4N2）. Thereafter, she experienced progressive shortness of breath. Therefore, a cardiac operation was performed 2 wk after the colorectal operation. Histological examination revealed adenocarcinoma, which was identical to the primary lesion. Although two- dimensional echocardiography has become the diagnostic test of choice for detecting cardiac tumors, in patients with colorectal cancer showing a cardiac mass, further diagnostic evaluation such as a magnetic resonance imaging might be necessary.

Evaluation of sorafenib for hepatocellular carcinoma by contrast-enhanced ultrasonography:A pilot study

AIM:To determine the usefulness of arrival time parametric imaging(AtPI) using contrast-enhanced ultrasonography(CEUS) with Sonazoid in evaluating early response to sorafenib for hepatocellular carcinoma(HCC).METHODS:Fourteen advanced HCC patients who received sorafenib 400/800 mg/d for at least 4 wk and were followed up by CEUS were enrolled in this study.CEUS was performed before treatment and 2 and 4 wk after treatment,and images of the target lesion in the arterial phase were recorded for each patient.The images were analyzed by AtPI.Color mapping(CM) images obtained by AtPI were compared before and after the treatment.In these CM images,the mean arrival time of the contrast agent in the region of interest from the starting point [mean time(MT)] was calculated.In each patient,differences between MT before and MT 2 and 4 wk after the treatment were compared with responses evaluated 4-8 wk after the treatment by dynamic computed tomography(CT),and statistical analysis was performed.Modified response evaluation criteria in solid tumors was used for the response evaluation.RESULTS:In CM images both 2 and 4 wk after the treatment,delays in the arrival time of the contrast agent were noted in 8 of the 14 patients.In the other 6 patients,no color changes were observed in the tumor,or red and/or yellow increase,suggesting a decrease in blood flow velocity between images 2 and 4 wk after the treatment and those before the treatment.Dynamic CT could be performed 4-8 wk after the treatment in 13 of the 14 patients.Median differences in the MT were 1.13 s and 1.015 s,2 and 4 wk after the treatment,respectively,in the 8 patients who showed stable disease(SD)/partial response(PR) on dynamic CT.Median differences in the MT were-0.39 s and-0.95 s,2 and 4 wk after the treatment,respectively,in the 5 patients who showed progressive disease(PD).Differences in the median MT between SD/PR and PD groups were significant 2 and 4 wk after the treatment with P = 0.019 and P = 0.028,respectively.CONCLUSION:AtPI by CEUS using Sonazoid is suggested to be useful for evaluating early responses to sorafenib.

Research of the Control Domain of Edges in Regression Testing

Regression testing is the process of validating modified software to provide confidence that the changed parts of the software behave as intended and that the unchanged parts have not been adversely affected by the modifications. The goal of regression testing is to reduce the test suit by testing the new characters and the modified parts of a program with the original test suit. Regression testing is a high cost testing method. This paper presents a regression testing selection technique that can reduce the test suit on the basis of Control Flow Graph (CFG). It import the inherit strategy of object-oriented language to ensure an edge’s control domain to reduce the test suit size effectively. We implement the idea by coding the edge. An algorithm is also presented at last.

Truss structural damage identification based on principal component analysis and multivariate control chart

The present paper addresses the subject of truss damage identification using measured frequency response functions (FRF). Damage identification matrix is formed using measured FRFs obtained from truss dynamic test. Then using principal component analysis (PCA),the variable space dimensions of damage identification matrix can be reduced,and original data characters of FRFs can be analyzed and extracted from lower dimension variable space. Thus truss damages can be identified using the multivariate control chart of first several order principal components which contain almost all of original data information. Without the need for modal parameters,the method avoids the errors of modal fitting. In order to validate the reliability of the method,a whole size truss was tested with six types of damage case concerning single or two element damages. The experimental result shows that the proposed method is straightforward and reliable for truss damage identification. Especially,the method has good applicability for the truss under noisy environment and non-linear cases.

Block-based test data adequacy measurement criteria and test complexity metrics

On the basis of software testing tools we developed for programming languages, we firstly present a new control flowgraph model based on block. In view of the notion of block, we extend the traditional program\|based software test data adequacy measurement criteria, and empirically analyze the subsume relation between these measurement criteria. Then, we define four test complexity metrics based on block. They are J\|complexity 0; J\|complexity 1; J\|complexity \{1+\}; J\|complexity 2. Finally, we show the Kiviat diagram that makes software quality visible.

Method of Precise Auto Tool Setting for Micro Milling

Based on microscope and image processing, a new method of auto tool setting for micro milling was presented. Firstly, a realtime image of tool setting area was obtained by microscope and CCD camera, then image processing was carried out on this image and the gap between the tool and workpiece was calculated. The gap measurement was sent to motion controlling card to make the tool approach to the surface of workpiece. These steps were repeated until the gap is zero, which means that tool setting was finished. Moreover, a reliability verification test was conducted. Results indicated that the precision of tool setting is satisfactory.

Investigating Iranian Test-takers＇ Performance Over Taking Different Modalities of Listening Comprehension Test

Visual and pictorial materials are extensively used in teaching listening comprehension textbooks. Although the use of still image is currently implemented in some distinguished testing systems, video test is not a popular modality due to the fact that this kind of test may result in test-takers＇ confusion during the test. In the present study, a sample of 80 Iranian EFL （English as a Foreign Language） students was selected to compare their performance on three different modalities of listening test： audio-only test, pictorial （listening with still image test）, and visual （video） listening test. The analysis of one-way repeated measure ANOVA （Analysis of Variance） was used to compare the students＇ scores. The results of Bonferroni Post Hoc Test confirm that there were significant differences in scores among audio-only, pictorial, and visual tests. The results of this study highlight the greater performance of students in pictorial listening test which is statistically significant.

The Hydraulic Control Using LabVIEW for a Synthetic Rubber Spring Testing Machine

The application is a control movement of two hydraulic cylinder for a synchronize movement. The main purpose of this paper is to show a short programming code in LabVIEW to control the movement of two cylinders with an automatic control program using only analog inputs from the sensor of pressure and linear displacement sensor and the digital output from the hydraulic valves. This is designed for one of the test of this synthetic rubber spring testing machine.

Calculation of Percentage of Coarse Aggregate Present in Concrete Using Processing of Digital Images Obtained with a Commercial Scanner

This paper presents a method for determining the percentage of coarse aggregate in concrete specimens by image processing. The test pieces were produced with the aim of obtaining images of their cross sections through a scanner table. In order to increase the contrast between mortar and coarse aggregate the sliced surfaces were treated with the phenolphthale in solution. The images obtained in the scanner were processed in a program developed with MATLAB （matrix laboratory）. The average coarse aggregate in each section and the mean of coarse aggregate per test body were calculated. With the results, it was revealed that the method returned satisfying results when compared to the original trace of the concrete.