“个数”与“对数”的数法

我们做几何题时，经常遇到数“个数”与“对数”的问题，不少同学感觉很难，下面谈几点看法，以供参考。

Reciprocal Distance Laplacian Eigenvalue Distribution Based on Graph Parameters

Let G be a connected graph of order n and m_(RD)^(L)_(G)I denote the number of reciprocal distance Laplacian eigenvaluesof G in an interval I.For a given interval I,we mainly present several bounds on m_(RD)^(L)_(G)I in terms of various structuralparameters of the graph G,including vertex-connectivity,independence number and pendant vertices.

AUTOMATIC MULTILEVEL THRESHOLDING METHOD BASED ON MAXIMUM ENTROPY

In the multilevel thresholding segmentation of the image, the classification number is always given by the supervisor. To solve this problem, a fast multilevel thresholding algorithm considering both the threshold value and the classification number is proposed based on the maximum entropy, and the self-adaptive criterion of the classification number is given. The algorithm can obtain thresholds and automatically decide the classification number. Experimental results show that the algorithm is effective.

Ontology-based framework for personalized recommendation in digital libraries

To promote information service ability of digital libraries, a browsing and searching personalized recommendation framework based on the use of ontology is described, where the advantages of ontology are exploited in different parts of the retrieval cycle including query-based relevance measures, semantic user preference representation and automatic update, and personalized result ranking. Both the usage and information resources can be exploited to extract useful knowledge from the way users interact with a digital library. Through combination and mapping between the extracted knowledge and domain ontology, semantic content retrieval between queries and documents can be utilized. Furthermore, ontology-based conceptual vector of user preference can be applied in personalized recommendation feedback.

韦氏脊柱整治手法结合核心肌群训练治疗非职业高尔夫运动者非特异性腰痛

目的:观察韦氏脊柱整治手法结合核心肌群训练治疗非职业高尔夫运动者非特异性腰痛的临床疗效。方法:将66例患有非特异性腰痛的非职业高尔夫运动者随机分为推拿综合组、手法综合组和强化训练组,每组22例。推拿综合组采用推拿手法联合场效应治疗,手法综合组采用韦氏脊柱整治手法联合场效应治疗,强化训练组采用韦氏脊柱整治手法联合场效应治疗和核心肌群训练;每周治疗3次,10次为1个疗程,共3个疗程。分别于治疗前、治疗结束后1个月和3个月记录并比较3组患者改良Oswestry功能障碍指数(Oswestry disability index,ODI),并于治疗结束后6个月采用自拟标准评价3组患者运动能力恢复情况。结果:(1)改良ODI。时间因素和分组因素存在交互效应(F=7.803,P=0.000);3组患者改良ODI比较,组间差异有统计学意义,即存在分组效应(F=22.786,P=0.000);治疗前后不同时间点之间改良ODI的差异有统计学意义,即存在时间效应(F=399.125,P=0.000);3组患者改良ODI随时间均呈降低趋势,但3组的降低趋势不完全一致[(69.39±7.35)%,(32.72±14.58)%,(19.80±11.43)%,F=191.759,P=0.000;(69.09±10.87)%,(44.34±11.93)%,(29.80±7.87)%,F=84.015,P=0.000;(73.13±10.73)%,(55.96±6.91)%,(37.58±6.36)%,F=187.706,P=0.000];治疗前3组患者改良ODI比较,差异无统计学意义(F=1.041,P=0.359);治疗结束后1个月,3组患者改良ODI比较,差异有统计学意义(F=22.114,P=0.000);强化训练组改良ODI低于手法综合组和推拿综合组(P=0.001,P=0.000),手法综合组改良ODI低于推拿综合组(P=0.001);治疗结束后3个月,3组患者改良ODI比较,差异有统计学意义(F=22.495,P=0.000);强化训练组改良ODI低于手法综合组和推拿综合组(P=0.000,P=0.000),手法综合组改良ODI低于推拿综合组(P=0.005)。(2)运动能力恢复效果。治疗结束后6个月,强化训练组优4例、良8例、可8例、差2例,手法综合组优1例、良4例、可6例、差11例,推拿综合组良2例、可2例、差18例;强化训练组运动恢复效果优于手法综合组和推拿综合组(R_(强化训练组)=19.73,R_(手法综合组)=35.41,R_(推拿综合组)=45.36,χ~2=20.497,P=0.000)。结论:采用韦氏脊柱整治手法联合场效应治疗和核心肌群训练、韦氏脊柱整治手法联合场效应治疗、推拿手法联合场效应治疗,均能缓解非职业高尔夫运动者的非特异性腰痛,改善腰椎功能,提高运动能力,但前者的疗效优于后两者。

A Graphlike Manifold Whose Contraction is

For a graphlike manifold whose contraction is a generalized cuneate figure,we deribve a formula in this paper to compute the number of homeomorphism classes of it by using twist operations and the combinatorial theory.

Wage and Income Distribution in China:Review and Outlook

Under the planned economy,China’s distribution relations were relations among the state,state-run enterprises,employees and the collective economy;relations between heavy industry and light industry;and relations between cities and the countryside.After China’s transition to a market-oriented economy,the distribution relations among the state,state-run enterprises and employees evolved into distribution relations between the government,enterprises and households;the distribution relations between heavy industry and light industry evolved into distribution relations between the state sector and the private sector;and the distribution relations between cities and the countryside evolved into distribution relations between original urban dwellers and migrant populations.Wage system reform was carried out throughout the transition of these three types of distribution relations.Income distribution contradictions in China,which are a problem left over from history and intrinsic to the market-based economy,eased over the years.Some people and regions achieved prosperity,and urban-rural and interregional income gaps narrowed.However,widening household income gaps pose barriers to China’s economic sustainability and vision of building a moderately prosperous society in all respects.Mechanisms to promote common prosperity are incomplete and inadequate.The disequilibrium of functional distribution is an important cause of these income inequalities.The overall wage level of ordinary workers is low.In the future,China'should give full play to the decisive role of the market in primary distribution to ensure proper return to all types of factors,and enhance redistribution to achieve common prosperity for all its people.

Existence and Uniqueness of the Nonlinear BSDEs with a Small Parameter under Locally Lipschitz Condition

In this paper we study the following nonlinear BSDE：y（t） ＋ ∫1 t f（s,y（s）,z（s））ds ＋ ∫1 t [z（s） ＋ g 1 （s,y（s）） ＋ εg 2 （s,y（s）,z（s））]dW s=ξ,t ∈ [0,1],where ε is a small parameter.The coefficient f is locally Lipschitz in y and z,the coefficient g 1 is locally Lipschitz in y,and the coefficient g 2 is uniformly Lipschitz in y and z.Let L N be the locally Lipschitz constant of the coefficients on the ball B（0,N） of R d × R d×r.We prove the existence and uniqueness of the solution when L N ～ √ log N and the parameter ε is small.

The Credibility Estimators under MLINEX Loss Function

In this paper, MLINEX loss function was considered to solve the problem of high premium in credibility models. The Bayes premium and credibility premium were obtained under MLINEX loss function by using a symmetric quadratic loss function. A credibility model with multiple contracts was established and the corresponding credibility estimator was derived under MLINEX loss function. For this model the estimations of the structure parameters and a numerical example were also given.

A Combined Admission and Priority Control Mechanism for Assuring Communication Quality in VANETs integrated with Wireless Mesh Networks

In this paper, we introduce a new combined priority and admission control mechanism applying in the VCN （Vehicular Communication Network） which is designed with an integration of the Vehicular Ad-hoc Networks （VANETs） based on standard IEEE 802.11 p and IEEE 802.11 s WMNs （Wireless Mesh Networks）. Simulation experiments are intensively investigated to evaluate the novel combined priority and admission control mechanism to assure quality of the I2V （Infrastructure to Vehicle） emergency services occurred during the time video flows are being delivered between content servers and cars. The simulation results show effectiveness of proposed priority and admission control schemes in term of the minimized end-to-end delay as well as the increase of throughput and PDR （Packet Delivery Ratio） of the emergency data flow.

Analyzing the Factors Affecting the Users＇ Success in Web Based Education： A Data Mining Approach

Corporations focus on web based education to train their employees ever more than before. Unlike traditional learning environments, web based education applications store large amount of data. This growing availability of data stimulated the emergence of a new field called educational data mining. In this study, the classification method is implemented on a data that is obtained from a company which uses web based education to train their employees. The authors＇ aim is to find out the most critical factors that influence the users＇ success. For the classification of the data, two decision tree algorithms, Classification and Regression Tree （CART） and Quick, Unbiased and Efficient Statistical Tree （QUEST） are applied. According to the results, assurance of a certificate at the end of the training is found to be the most critical factor that influences the users＇ success. Position, number of work years and the education level of the user, are also found as important factors.

Developing a Data Modelling Tool to Visualize the Transformation of an ER Diagram into a Relational Schema

In this paper, the authors present the development of a data modelling tool that visualizes the transformation process of an ＂Entity-Relationship＂ Diagram （ERD） into a relational database schema. The authors＇ focus is the design of a tool for educational purposes and its implementation on e-learning database course. The tool presents two stages of database design. The first stage is to draw ERD graphically and validate it. The drawing is done by a learner. Then at second stage, the system enables automatically transformation of ERD to relational database schema by using common rules. Thus, the learner could understand more easily how to apply the theoretical material. A detailed description of system functionalities and algorithm for the conversion are proposed. Finally, a user interface and usage aspects are exposed.

Sound transducer calibration of ambulatory audiometric system utilizing delta learning rule

An efficient calibration algorithm for an ambulatory audiometric test system is proposed. This system utilizes a personal digital assistant (PDA) device to generate the correct sound pressure level (SPL) from an audiometric transducer such as an earphone. The calibrated sound intensities for an audio-logical examination can be obtained in terms of the sound pressure levels of pure-tonal sinusoidal signals in eight-banded frequency ranges (250, 500, 1 000, 2 000, 3 000, 4 000, 6 000 and 8 000 Hz), and with mapping of the input sound pressure levels by the weight coefficients that are tuned by the delta learning rule. With this scheme, the sound intensities, which evoke eight-banded sound pressure levels by 5 dB steps from a minimum of 25 dB to a maximum of 80 dB, can be generated without volume displacement. Consequently, these sound intensities can be utilized to accurately determine the hearing threshold of a subject in the ambulatory audiometric testing environment.

Games-Based Learning Framework

This work presents the authors＇ experience in the field of mobile technologies, from which several initiatives have emerged. As result of this, a games-based framework for learning has been developed in these last years. This framework is composed by a competition called Mobigame, which has as main aim to stimulate the participation of the students. By participating in this competition participants learn to develop for mobile devices. A game to practice Japanese is also presented in this article, which was presented in the above mentioned competition. This game has been developed for mobile phones or PDAs （Personal Digital Assistants） based on the JME （Java Mobile Edition） technology. Finally, another initiative is also presented： A free download platform of digital contents for mobile devices based on info-educational games.

Pathological and MR-DWI study of the acute hepatic injury model after stem cell transplantation

AIM： To investigate apparent diffusion coefficient （ADC） values as an indication of reconditioning of acute hepatic injury （AHI） after allogeneic mononuclear bone marrow cell （MBMC） transplantation. METHODS： Three groups were used in our study： a cell transplantation group （n = 21）, transplantation control group （n = 21） and normal control group （n = 10）. AHI model rabbits in the cell transplantation group were injected with 5 mL of MBMC suspension at multiple sites in the liver and the transplantation controls were injected with 5 mL D-Hanks solution. At the end of the 1st, 2nd and 4th wk, 7 rabbits were randomly selected from the cell transplantation group and trans- plantation control group for magnetic resonance diffu- sion-weighted imaging （MR-DWI） and measurement of the mean ADC values of injured livers. After MR-DWI examination, the rabbits were sacrificed and the livers subjected to pathological examination. Ten healthy rab- bits from the normal control group were used for MR- DWI examination and measurement of the mean ADC value of normal liver. RESULTS： At all time points, the liver pathological scores from the cell transplantation group were significantly lower than those in the transplantation control group （27.14± 1.46 vs 69.29± 6.16, 22.29 ± 2.29 vs 57.00± 1.53, 19.00 ± 2.31 vs 51.86 ± 6.04, P = 0.000）. The mean ADC values of the cell transplantation group were significantly higher than the transplantation con- trol group （（1.07± 0.07） ×10^-3 mm2/s vs （0.69 ± 0.05） ×10^-3 mm2/s, （1.41± 0.04） ×10^-3 mm2/s vs （0.84± 0.03） ×10^-3 mm2/s, （1.68 ± 0.04） ×10^-3 mm2/s vs （0.86± 0.04） ×10^-3 mm2/s, P = 0.000）. The pathological scores of the cell transplantation group and transplantation control group gradually decreased. However, their mean ADC values gradually increased to near that of the normal control. At the end of the 1st wk, the mean ADC values of the cell transplantation group and transplantation control group were significantly lower than those of the normal control group [（1.07 ± 0.07） ×10^-3 mm2/s vs （± 0.03） ×10^-3 mm2/s, （0.69± 0.05） ×10^-3 mm2/s vs （1.76 ± 0.03） ×10^-3 mm2/s, P = 0.000]. At any 2 time points, the pathological scores and the mean ADC values of the cell transplantation group were significantly different （P = 0.000）. At the end of the 1st wk, the pathological scores and the mean ADC values of the transplantation control group were significantly different from those at the end of the 2nd and 4th wk （P = 0.000）. However, there was no significant difference between the 2nd and 4th wk （P = 0.073 and 0.473, respectively）. The coefficient of correlation between the pathological score and the mean ADC value in the cell transplantation group was -0.883 （P = 0.000） and -0.762 （P = 0.000） in the transplantation control group. CONCLUSION： Tracking the longitudinally dynamic change in the mean ADC value of the AHI liver may reflect hepatic injury reconditioning after allogeneic MBMC transplantation.

An investigation on dissolution kinetics of single sodium carbonate particle with image analysis method

Dissolution kinetics of sodium carbonate is investigated with the image analysis method at the approach of single particle.The dissolution experiments are carried out in an aqueous solution under a series of controlled temperature and p H.The selected sodium carbonate particles are all spherical with the same mass and diameter.The dissolution process is quantified with the measurement of particle diameter from dissolution images.The concentration of dissolved sodium carbonate in solvent is calculated with the measured diameter of particle.Both surface reaction model and mass transport model are implemented to determine the dissolution mechanism and quantify the dissolution rate constant at each experimental condition.According to the fitting results with both two models,it is clarified that the dissolution process at the increasing temperature is controlled by the mass transport of dissolved sodium carbonate travelling from particle surface into solvent.The dissolution process at the increasing pH is controlled by the chemical reaction on particle surface.Furthermore,the dissolution rate constant for each single spherical sodium carbonate particle is quantified and the results show that the dissolution rate constant of single spherical sodium carbonate increases significantly with the rising of temperature,but decreases with the increasing of pH conversely.

Validation of prognostic indices in Egyptian Budd-Chiari syndrome patients: A single-center study

AIMTo compare predictive ability of Budd-Chiari syndrome (BCS) prognostic indices (PIs) for one-year survival and Transjugular intrahepatic portosystemic shunt (TIPS) patency.METHODSThis retrospective study enrolled 194 Egyptian patients with primary BCS who presented to the Budd-Chiari Study Group of Ain Shams University Hospital. Calculation of the available PIs was performed using Child-Pugh and model for end-stage liver disease scores, BCS-specific PIs (Clichy, New Clichy and Rotterdam) for all patients, and BCS-TIPS PI only for patients who underwent TIPS. The overall one-year survival rate and the one-year shunt patency rate for TIPS were reported.RESULTSThe overall one-year survival rate was 69.6%, and the New Clichy PI revealed the best validity for its prediction at a cut-off value of 3.75, with sensitivity and specificity of 78% and 73.3%, respectively [area under receiver operating characteristic curve (AUC) = 0.806]. The one-year survival rate post-TIPS was 89.7%, and the BCS-TIPS score demonstrated validity for its prediction at a cut-off value of 3.92 (sensitivity and specificity were 71.4% and 64.5%, respectively) (AUC = 0.715). Logistic regression analysis revealed that the New Clichy PI (P = 0.030), high serum total bilirubin (P = 0.047) and low albumin (P < 0.001) were independent factors for predicting mortality within one year. The one-year shunt patency rate in TIPS was 80.2%, and none of the PIs exhibited significant validity for its prediction.CONCLUSIONThe New Clichy score could independently predict the one-year survival in Egyptian BCS patients.

Experimental and modeling study on dust cake profile and its influence on pressure drop in fiber filter

Alumina （MMAD： 32.45μm） was used to study dust cake formation in fiber filter at steady-state operation. Cake vertical profile along filter medium versus filtration velocity （ranging from 3 to 7cm/s）, particle concentration （ranging from 40 to 120g/m^3） and particle areal mass to filter （ranging from 0.57 to 2.86 kg/m^2）, was researched by experiments and modeling. The filtration was carried through by a plane filter media （Material： Terylene felt, Thickness： 1.8mm） covered on a framework which was fixed in a filter. During filtration, the cake thickness was measured up and down by a mobile microscope and a camera controlled by a PC. The results showed that the cake vertical profile accord with a peak function. The peak amplitude A, center displacement xc, the shape parameters W of the peak function was greatly depended on filtration velocity and particle areal mass to filter, whereas slightly on particle concentration. The relationships between the three coefficients （peak amplitude A, center displacement xc, the shape parameters W） and filtration velocity, areal mass to filter, particle concentration were associated as equations, based on which pressure drop model was deduced. The peak function and pressure drop model were verified with experimental data.

Exploration and Practice of Improving Higher Mathematics Teaching Quality of Teaching at Different Levels

Teaching content of Higher Mathematics is systematic and rigor with a high degree of abstraction. Because different students are on the different basis and different disciplines have various requirements, mathematics is generally difficult for students. In order to improve the quality of teaching mathematics, we should make use of individualized teaching and teaching by different levels in order to achieve the best teaching results.