PLANNING METHOD OF TOOL ORIENTATION IN FIVE-AXIS NC MACHINING

The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by introducing the key frame idea in the animation-making. According to the feature of the part, several key tool orientations are set without interference between the tool and the part. Then, these key tool orientations are inter- polated by the spline function. By mapping the surface parameter to the spline parameter, the spline function value is obtained and taken as the tool orientation when generating the CL file. The machining result shows that the proposed method realizes the global smoothing of the tool orientation and the continuity of the rotational speed and the rotational acceleration. It also avoids the shake of the machine tool and improves the machining quality.

A NEW ALGORITHM BASED ON TRIANGULATION FOR 5 AXIS MACHINING OF SCULPTURED SURFACES

NC machining path of sculptured surfaces in CAD/CAM system plays an important role on manufacture. This paper describes a new algorithm for 5 axis machining of sculptured surfaces and the algorithm is interference free. The approach includes: (1) the tesselation of the parametric surfaces into triangles; (2) building topological relations among triangles;(3) 5 axis tool path generation; (4) interference detection and tool position correction.

Mathematical Definitions of Operators for Cartographic Generalization

This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly limited qualitative concepts.The meaning of mathematical definition of operators for cartographic generalization and the application prospect in computer_aided cartography (CAC) is stated.ract The Jurassic strata in Jingyan of Sichuan containing the Mamenchinsaurus fauna are dealt with and divided in this paper. The Mamenchisaurus fossils contained there are compared in morphological features and stratigraphically with other types of the genus on by one. The comprehensive analysis show that the Mamenchisaurus fauna of Jingyan appeared in the early Late Jurassic and is primitive in morphology. The results of the morphological identification and stratigraphical study agree with each other. Their evolutionary processes in different apoches of the Late Jurassic also made clear. Key words Jingyan, Sichuan, Mamenchisaurus Fauna, stratigraphy, evolution

AN APPROACH TO FEATURE-BASED PARAMETRIC DESIGN FOR DIE AND MOULD

An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is described by parent-child operator structure.The feature shape and location can be modified by design parameters.An expert system is used for deriving a geometry of the features which satisfies the given constraints.This approach provides a more natural and convenient method of representing a parametric model of the die and mould.

OBJECT ORIENTED DATA MODELLING WITH APPLICATIONS TO CAD

An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented.

L~∞-Error Estimate of a Nonconfoming Rectangular Plate Element

In this paper,a nonconforming rectangular plate element,the modified incomplete biquadratic plate element,is considered. The asympotic optimal L~∞-error estimate is obtained for the plate bending problem. This proof is based on the method of regularized Green's function and 'the trick of auxiliary element'.

IMPROVEMENTS IN HIDDEN LINE REMOVAL ALGORITHM FOR BI-PARAMETRIC SURFACES

A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results. The enclosure test is done using area coordinates. A technique of moving box of encirclement is presented. It is found that the algorithm is of general purpose, requires minimal computer storage, has high accuracy and simplicity, and is very easy to be implemented on a computer.

A mathematical model of symmetry based on mathematical definition

Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disign/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance because of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarify: (1) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements; after which, the mathematical models of symmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis.

Some Hardy Type Inequalities in R^n

Some Hardy type inequalities on the ball and its complementary set in the Euclidean space are established by using the Picone type identity and constructing suitable auxiliary functions.

Effect of multidisciplinary team treatment on outcomes of patients with gastrointestinal malignancy

AIM: To evaluate the effect of multidisciplinary team (MDT) treatment modality on outcomes of patients with gastrointestinal malignancy in China. METHODS: Data about patients with gastric and colorectal cancer treated in our center during the past 10 years were collected and divided into two parts. Part 1 consisted of the data collected from 516 consecutive complicated cases discussed at MDT meetings in Peking University School of Oncology (PKUSO) from December 2005 to July 2009. Part 2 consisted of the data collected from 263 consecutive cases of resect-able locally advanced rectal cancer from January 2001 to January 2005. These 263 patients were divided into neoadjuvant therapy (NT) group and control group. Patients in NT group received MDT treatment, namely neoadjuvant therapy + surgery + postoperative adjuvant therapy. Patients in control group underwent direct surgery + postoperative adjuvant therapy. The outcomes in two groups were compared. RESULTS: The treatment strategy was altered after discussed at MDT meeting in 76.81% of gastric cancer patients and in 58.33% of colorectal cancer patients before operation. The sphincter-preservation and local control of tumor were better in NT group than in control group. The 5-year overall survival rate was also higher in NT group than in control group (77.23% vs 69.75%, P = 0.049). CONCLUSION: MDT treatment modality can significantly improve the outcomes of patients with gastrointestinal malignancy in China.

Evaluation of the Assistant Function with Four Zeros and all Nonprincipal Characters but X1X2X3X4

To obtain a better Vinogradov's bound, assistant function with two or three zeros and all Dirichlet's characters has been evaluated. Assistant function g(X1,X2,X3,X4)with four zeros and all nonprincipal characters but X1X2X3X4 is constructed and evaluated in the paper. And the constant obtained is 8.395 511 841 994.

Influence of Auxiliary Equation on Wave Functions for Time-Dependent Pauli Equation in Presence of Aharonov-Bohm Effect

Invariant operator method for discrete or continuous spectrum eigenvalue and unitary transformation approach are employed to study the two-dimensional time-dependent Pauli equation in presence of the Aharonov-Bohm effect （AB） and external scalar potential. For the spin particles the problem with the magnetic field is that it introduces a singularity into wave equation at the origin. A physical motivation is to replace the zero radius flux tube by one of radius R, with the additional condition that the magnetic field be confined to the surface of the tube, and then taking the limit R → 0 at the end of the computations. We point that the invariant operator must contain the step function θ（r - R）. Consequently, the problem becomes more complicated. In order to avoid this dimculty, we replace the radius R by ρ（t）R, where ρ（t） is a positive time-dependent function. Then at the end of calculations we take the limit R →0. The qualitative properties for the invariant operator spectrum are described separately for the different values of the parameter C appearing in the nonlinear auxiliary equation satisfied by p（t）, i.e., C 〉 0, C = 0, and C 〈0. Following the C＇s values the spectrum of quantum states is discrete （C 〉 0） or continuous （C ≤ 0）.

Redlining in Residential Mortgages in Johannesburg, South Africa

The aim of the research in the paper was to study redlining practice within the greater Johannesburg area. The aim can be summarised by the following objectives： firstly, to investigate the evidence of redlining in the Greater Johannesburg area and to test its existence; secondly, to investigate the reasons why the areas were redlined; thirdly, to understand what the South Africa government and society did to combat the redlining practice. The research methodology was based on a questionnaire and interviews. A pool of respondents from the Greater Johannesburg suburbs that had interest or were affected by the practice of redlining was sought and interviewed. Analysis of the responses was made and conclusions were drawn from the responses. Secondary data was also sought from publications on the redlining practice to support the primary interviews data. From the interview responses and the secondary data, it was established that redlining existed in Greater Johannesburg and that the areas where redlining was practised could be marked on a map.

Green Highway for Malaysia： A Literature Review

This paper reviewed on the green highway definition and green highway terminology to improve knowledge and awareness of green highway for highway construction projects. Moreover, this paper discussed briefly on the rating system for green highway by highlighting various eight rating systems for green highway. This study adopted the secondary data from previous research and findings on green highway construction from all over the world. With regard to published articles on green highways, the outcome of the paper will examine several major issues in green highway which are the definition of green highway, terminology used for green highway aspects, green highway initiatives and green highway rating systems from all over the world.

A motion retargeting algorithm based on model simplification

A new motion retargeting algorithm is presented, which adapts me motion capture data to a new character. To make the resulting motion realistic, the physically-based optimization method is adopted. However, the optimization process is difficult to converge to the optimal value because of high complexity of the physical human model. In order to address this problem, an appropriate simplified model automatically determined by a motion analysis technique is utilized, and then motion retargeting with this simplified model as an intermediate agent is implemented. The entire motion retargeting algorithm involves three steps of nonlinearly constrained optimization： forward retargeting, motion scaling and inverse retargeting. Experimental results show the validity of this algorithm.

Modeling the Axial Balancing Mechanism of Orbit Annular Hydraulic Machines

A customized combined methodology based on both 2D CFD （computational fluid dynamics） and lumped parameters numerical modeling, useful for simulating the hydraulic behavior of orbit annular machines, has been developed and here presented. More in details, the predictive capabilities of this CAE （computer-aided engineering） tool can be applied for the study of both roller and gerotor architectures and considering both pumping and motoring operating mode. First of all, an in-house developed 2D CFD methodology, based on the integration of the stationary form of the Reynolds equation for the determination of the pressure distribution inside the lateral clearances bounded by the sides of the stator-rotor group and the valve plate, as well as the internal manifold surface, is firstly presented and applied. The same computational procedure has been also involved for the investigation of the leakages through the clearance between the valve plate and the balancing ring. After that, a lumped and distributed parameters numerical model has been involved for the simulation of a typical orbit roller motor operation. In this case, particular care has been devoted to the modeling of the axial leakage clearances, adopting analytical interpolation functions deducted from the numerical results calculated applying the previously described 2D CFD methodology. Finally, the whole CAE approach has been validated by means of a comprehensive numerical versus experimental comparison, obtaining a general good accordance for the overall operating field of this particular type of hydraulic unit.

Adaptive Surface Reconstruction Based on Tensor Product Algebraic Splines

Surface reconstruction from unorganized data points is a challenging problem in Computer Aided Design and Geometric Modeling. In this paper, we extend the mathematical model proposed by Juttler and Felis （Adv. Comput. Math., 17 （2002）, pp. 135-152） based on tensor product algebraic spline surfaces from fixed meshes to adaptive meshes. We start with a tensor product algebraic B-spline surface defined on an initial mesh to fit the given data based on an optimization approach. By measuring the fitting errors over each cell of the mesh, we recursively insert new knots in cells over which the errors are larger than some given threshold, and construct a new algebraic spline surface to better fit the given data locally. The algorithm terminates when the error over each cell is less than the threshold. We provide some examples to demonstrate our algorithm and compare it with Juttler＇s method. Examples suggest that our method is effective and is able to produce reconstruction surfaces of high quality.

Themes in Corporate Social Responsibility （CSR） and Rural Development Thinking： 1950s-2000s

This paper describes a brief overview of both corporate social responsibilities （CSR） and rural development （RD） ideas since the last 50 years. It aims at comparing and contrasting the both （CSR and RD） thoughts, and searches an initiative to expand the sustainable development achievement. Using secondary data from libraries studies, the progress of each thought will be identified to find out its advantages and weaknesses. Then, the result showed that the timeline perspectives come up with the conjunction idea of sustainability. In order to be more sustainable in development, then, the idea of CSR--as a tool for gaining sustainability in RD--should be transformed into ＂social business＂ approach. Here, there is a change in the time of taking decision about profit from ＂the last to the first＂. The paper contains four sub-topics： （1） definition and progress of CSR; （2） change in RD themes; （3） CSR, RD and social business; and （4） transformation of CSR to social business. The process of transformation from CSR to social business should include following agenda： （1） tailoring public-private partnerships to the local context; （2） providing resources, horizon and commitment; and （3） encouraging further innovation. This new position requires a shift in corporate law as well as establishing good corporate governance.

Algorithm of brush short-circuit coeffcients of DC machines for extremely low speed drives

When a direct-current （DC） machine runs at extremely low speed or standstill, the reduction in the armature resistance and the armature flux linkage due to the short circuited coils by the brushes on the commutator should not be neglected. Taking this reduction effect into account, the average values of the reduction coefficients relate to the machine parameters in complicated forms. In this paper, an effective algorithm for the precise computation of the average values of these reduction coefficients is proposed. Furthermore, in the algorithm, the effect of the insulation thickness between the commutator segments and the multiplicity of the wave winding are considered for the first time. The proposed algorithm can also be accommodated into the computer-aided design （CAD） of a DC machine, which normally runs at extremely low speed or standstill.