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This research focuses on the approach adopted by a university of science and technology in Taiwan (hereinafter the university) to develop students’ employability indices and to explore the questionnaire analyses. The university developed the “Employability Map; E-Map” by weighting the learning hours, which was used to evaluate students’ various employability items over the course of their schooling. Considering it not so appropriate to use students’ credits on courses to be the standard of judgment, the Department of Computer Science & Information Engineering (hereinafter the department) proposed an innovative method to convert the E-Map of weighting by learning achievement to conduct assessments that is more reflection students' employability indices for graduate, and analyzed the questionnaires of alumni and their employers’ various core employability indices. From those questionaires, finding the graduating students and alumni are lack of self-confidentce. The statistical data shall serve as a reference for guiding students at course selection, as well as improving department courses and planning. Keywords: employability indices, employability map, learning achievement, learning portfolio.

This study is aimed to build up a structure of circular city planning index with Essential Analysis Model (EAM). As countries around the world are engaged in finding solutions against increasingly exhausting resources and energies, the circular city is trending the metro development in future. This mandates a structure for index in circular city planning in future. To ensure the practice of the structure, it is to be based on circular economy and derived by “target oriented” essence logic. This study employs semi-structured exert interview to get professional inputs from more comprehensive population. A hierarchical structure of 18 major and 53 minor indexes is set up with the help of mind map software which may be referenced by government agencies, metro governance, urban and rural planning, and relevant competent authority in their circular city planning endeavor.

Surveying exercise is a fundamental course for Civil Engineering students. This course is featured with field operation. This study explores the design of an e-learning platform for the surveying exercise course. The issues on organizing digital contents such as recorded video of the standard instrument operation, editing learning materials, and constructing the portfolio for the learning process, as well as generating learning motivation, are discussed. Noting the uploaded videos, publishing articles and commentaries, interactive examination sessions, assessing for each other, and mobile device accessing, are found to be useful elements for this platform.

Atypical chemokine receptor CXCR7 (ACKR3) functions as a scavenger receptor for chemokine CXCL12, a molecule that promotes multiple steps in tumor growth and metastasis in breast cancer and multiple other malignancies. Although normal vascular endothelium expresses low levels of CXCR7, marked upregulation of CXCR7 occurs in tumor vasculature in breast cancer and other tumors. To investigate effects of endothelial CXCR7 in breast cancer, we conditionally deleted this receptor from vascular endothelium of adult mice, generating CXCR7(ΔEND/ΔEND) animals. CXCR7(ΔEND/ΔEND) mice appeared phenotypically normal, although these animals exhibited a modest 35±3% increase in plasma CXCL12 as compared with control. Using two different syngeneic, orthotopic tumor implant models of breast cancer, we discovered that CXCR7(ΔEND/ΔEND) mice had significantly greater local recurrence of cancer following resection, elevated numbers of circulating tumor cells and more spontaneous metastases. CXCR7(ΔEND/ΔEND) mice also showed greater experimental metastases following intracardiac injection of cancer cells. These results establish that endothelial CXCR7 limits breast cancer metastasis at multiple steps in the metastatic cascade, advancing understanding of CXCL12 pathways in tumor environments and informing ongoing drug development targeting CXCR7 in cancer.

We demonstrate the effective self-assembly of Au nanoparticles array by porous anodic alumina templates. It is interesting that ‘triangular island’ nanostructure appears on the surface of porous anodic alumina template. Every ‘triangular island’ arises in the adjacent area among three close holes. Using vacuum deposition and thermal dewetting, Au nanoparticles ordered hexagonal array is fabricated on the porous anodic alumina. During optical characterisation, the absorption peaks of Au nanoparticles array are red shifted as the incidence angle increases. Also, Raman scattering spectra intensity of Au nanoparticles hexagonal array nanostructure is a hundred times larger than the contrast substrate material.

We proposed the idea of establishing computer adaptive learning platform for Calculus. Students can do self-testing using the system any time after learning. Computerized adaptive testing (CAT) is used in the assessment of tests in this learning platform. The system gives students adaptive testing items to collect and to examine students’ learning situation. After analyzing students’ learning portfolio, the system sends the information to the teacher so that he realize the learning situations for every student at any time. This learning platform will be a great help when students’ learning Calculus.

Chemokines critically regulate chemotaxis in normal and pathologic states, but there is limited understanding of how multicellular interactions generate gradients needed for cell migration. Previous studies of chemotaxis of CXCR4+ cells toward chemokine CXCL12 suggest the requirement of cells expressing scavenger receptor CXCR7 in a source-sink system. We leveraged an established microfluidic device to discover that chemotaxis of CXCR4 cells toward distinct isoforms of CXCL12 required CXCR7 scavenging only under conditions with higher than optimal levels of CXCL12. Chemotaxis toward CXCL12-β and -γ isoforms, which have greater binding to extracellular molecules and have been largely overlooked, was less dependent on CXCR7 than the more commonly studied CXCL12-α. Chemotaxis of CXCR4+ cells toward even low levels of CXCL12-γ and CXCL12-β still occurred during treatment with a FDA-approved inhibitor of CXCR4. We also detected CXCL12-γ only in breast cancers from patients with advanced disease. Physiological gradient formation within the device facilitated interrogation of key differences in chemotaxis among CXCL12 isoforms and suggests CXCL12-γ as a biomarker for metastatic cancer.

Patients often present to the emergency department with loss of consciousness. The differential diagnosis of such condition may be difficult because of limited clinical information. The authors present a case of subarachnoid haemorrhage (SAH) with initial electrocardiographic (ECG) finding mimicking ST-segment elevation myocardial infarction (STEMI), which was confirmed to resolve in a follow-up study. Accurate and timely diagnosis of SAH-related ST-segment elevation was important, as the therapeutic strategy for SAH is completely different from that for STEMI. If the clinicians do not have other tools for diagnosis, the follow-up ECG may help us make a most possible diagnosis.

We study spectral-Galerkin methods (SGM) for nonlinear eigenvalue problems, where the Legendre polynomials are used as the basis functions for the trial function space. The SGM is applied to find the ground state solution of the Gross–Pitaevskii equation (GPE) and the GPE in a periodic potential. When the SGM is incorporated in the context of continuation methods for curve-tracking, a manifest advantage is that the target points are very close to the bifurcation points. Thus it takes less continuation steps to reach the target point when compared with the centered difference methods (CDM) or finite element methods (FEM). We also implement the spectral collocation method (SCM) so that the computational cost for the numerical integration in the SGM can be saved. Comprehensive numerical experiments on the GPE using various numerical methods described in this paper are reported.

A series of 3-(phenoxy-phenyl-methyl)-pyrrolidine analogues were discovered to be potent and balanced norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT) reuptake inhibitors. Several of these compounds were identified to have suitable in vitro pharmacokinetic properties for an orally dosed and CNS-targeted drug. Compound 39b, in particular, was identified as a potent NET and SERT reuptake inhibitor (NSRI) with minimal off-target activity and demonstrated robust efficacy in the spinal nerve ligation model of pain behavior.

A dramatic band gap narrowing of 1.61 eV has been observed in Co-doped nanocrystals of CeO2 (ceria), as a result of thermal annealing, without changing the ceria crystal structure and the Co concentration. As demonstrated by x-ray absorption fine structures, thermal annealing incurs an oxygen coordination rearrangement around Co atoms from an octahedral coordination to a square-planar coordination. First principle calculation using density functional theory reveals two stable oxygen coordination types surrounding Co, consistent with the experimental observation. The band gap values calculated for the two stable coordination types differ dramatically, reproducing the experimentally observed band gap narrowing. These prominent effects due to local structure rearrangement around dopant atoms can lead to unprecedented methods for band gap engineering in doped nanocrystal oxides.

We study spectral-Galerkin methods (SGM) and spectral collocation methods (SCM) for parameter-dependent problems, where the Fourier sine functions are used as the basis functions. When the SGM and the SCM are incorporated in the context of a Taylor predictor-inexact Newton corrector continuation algorithm for tracing solution curves of the Gross-Pitaevskii equation (GPE), they can efficiently provide accurate numerical solutions for the GPE. We show how the inexact Newton method outperforms the classical Newton method in the continuation algorithm. In our numerical experiments, the centered difference method (CDM), the SGM and SCM are exploited to compute energy levels and wave functions of a rotating Bose-Einstein condensation (BEC) and a rotating BEC in optical lattices in 2D. Sample numerical results are reported.

First-principles calculations within the generalized gradient approximation are employed to calculate the electronic properties of the bilayer AA-stacked zigzag nanographene ribbon. The AFM–AFM configuration (antiferromagnetic and antiferromagnetic configurations for the intralayer and interlayer spin arrangements, respectively) is predicted to be the most stable system. The interlayer interactions alter the band structure such as the modulation of energy dispersions, the generation of new band-edge states, and the state degeneracy. The energy gap is inversely proportional to the ribbon width. As compared with the monolayer zigzag nanographene ribbon, the density of states exhibits more asymmetric peaks, and some peaks at low energy are enhanced due to the state degeneracy. These predicted results can be identified by scanning tunneling spectroscopy (STS) or the measurements of optical spectra.

Bloch waves of Bose–Einstein condensates (BEC) in optical lattices are extremum nonlinear eigenstates which satisfy the time-independent Gross–Pitaevskii equation (GPE). We describe an efficient Taylor predictor–Newton corrector continuation algorithm for tracing solution curves of parameter-dependent problems. Based on this algorithm, a novel two-stage continuation algorithm is developed for computing Bloch waves of 1D and 2D Bose–Einstein condensates (BEC) in optical lattices. We split the complex wave function into the sum of its real and imaginary parts. The original GPE becomes a couple of two nonlinear eigenvalue problems defined in the real domain with periodic boundary conditions. At the first stage we use the chemical potential μ as the continuation parameter. The Bloch wavenumber k (kx,ky), and the coefficient of the cubic term are treated as the second and third continuation parameters, respectively. Then we compute the Bloch bands/surfaces for the 1D/2D problem with linear counterparts. At the second stage we use μ and k/kx or ky as the continuation parameters simultaneously with two constraint conditions. The states without linear counterparts in the GPE can be obtained via states with linear counterparts. Numerical results are reported for both 1D and 2D problems.

We present a novel multigrid-continuation method for treating parameter-dependent problems. The proposed algorithm which can be flexibly implemented is a generalization of the two-grid discretization schemes [C.-S. Chien, B.-W. Jeng, A two-grid discretization scheme for semilinear elliptic eigenvalue problems, SIAM J. Sci. Comput. 27 (2006) 1287–1304]. That is, approximating points on a solution curve do not necessarily lie on the same fine grid. We apply the algorithm to compute energy levels and superfluid densities of Bose–Einstein condensates (BEC) in a periodic potential. Both positive and negative scattering lengths are considered in our numerical experiments. For positive scattering length, if the chemical potential is large enough, and the domain is properly chosen, the results show that the number of peaks of the first few energy states of the 2D BEC in a periodic potential depends on the wave number of the periodic potential. Moreover, for bright solitons the number of peaks of the ground state solutions is (1d−1)2 and (1d)2, where the periodic potential is expressed in terms of the sine or the cosine functions, respectively. However, these formulae do not hold if the scattering length is negative. The numerical study is extended to the two-component, 1D and 2D BEC in a periodic potential.

We study Adini’s elements for nonlinear Schrodinger equations (NLS) defined in a square box with periodic boundary conditions. First we transform the time-dependent NLS to a time-independent stationary state equation, which is a nonlinear eigenvalue problem (NEP). A predictor–corrector continuation method is exploited to trace solution curves of the NEP. We are concerned with energy levels and superfluid densities of the NLS. We analyze superconvergence of the Adini elements for the linear Schrodinger equation defined in the unit square. The optimal convergence rate Oðh 6 Þ is obtained for quasiuniform ele

We briefly review a class of nonlinear Schrodinger equations (NLS) which govern various physical phenomenon of Bose–Einstein condensation (BEC). We derive formulas for computing energy levels and wave functions of the Schrodinger equation defined in a cylinder without interaction between particles. Both fourth order and second order finite difference approximations are used for computing energy levels of 3D NLS defined in a cubic box and a cylinder, respectively. We show that the choice of trapping potential plays a key role in computing energy levels of the NLS. We also investigate multiple peak solutions for BEC confined in optical lattices. Sample numerical results for the NLS defined in a cylinder and a cubic box are reported. Specifically, our numerical results show that the number of peaks for the ground state solutions of BEC in a periodic potential depends on the distance of neighbor wells.

We study a finite difference continuation (FDC) method for computing energy levels and wave functions of Bose–Einstein condensates (BEC), which is governed by the Gross–Pitaevskii equation (GPE). We choose the chemical potential λ as the continuation parameter so that the proposed algorithm can compute all energy levels of the discrete GPE. The GPE is discretized using the second-order finite difference method (FDM), which is treated as a special case of finite element methods (FEM) using the piecewise bilinear and linear interpolatory functions. Thus the mathematical theory of FEM for elliptic eigenvalue problems (EEP) also holds for the Schrodinger eigenvalue problem (SEP) associated with the GPE. This guarantees the existence of discrete numerical solutions for the ground-state as well as excited-states of the SEP in the variational form. We also study superconvergence of FDM for solution derivatives of parameter-dependent problems (PDP). It is proved that the superconvergence O(h t ) in the discrete H 1 norm is achieved, where t = 2a ndt = 1.5 for rectangular and polygonal domains, respectively, and h is the maximal boundary length of difference grids. Moreover, the FDC algorithm can be implemented very efficiently using a simplified two-grid scheme for computing energy levels of the BEC. Numerical results are reported for the ground-state of two-coupled NLS defined in a large square domain, and in particular, for the second-excited state solutions of the 2D BEC in a periodic potential. © 2008 Elsevier B.V. All rights reserved.

We describe adaptive continuation algorithms for computing energy levels of the Bose–Einstein condensates (BEC) with emphasis on the rotating BEC. We show that the rotating BEC in the complex plane is governed by special two-coupled nonlinear Schrodinger equations (NLS) in the real domain, which makes the eigenvalues of the discrete coefficient matrix at least double. A predictor–corrector continuation method is used to trace solution curves of the rotating BEC defined in square domains. The wave functions of the rotating BEC can be easily obtained whenever the solution curves of the two-coupled NLS are numerically traced. From the physical point of view, the proposed algorithm has the advantage that the energy levels of the system are computed intuitively, where the energy information of the associated Schrodinger eigenvalue problem is fully exploited. The superfluid density we obtain on the first solution branch resembles the figure shown in [J.R. Anglin, W. Ketterle, Nature 416 (2002) 211]. We also obtain superfluid densities on the other solution branches, which to the best of our knowledge, have never shown up in the literatures.

We present a novel algorithm for computing the ground-state and excited-state solutions of M-coupled nonlinear Schrodinger equations (MCNLS). First we transform the MCNLS to the stationary state ones by using separation of vari- ables. The energy level of a quantum particle governed by the Schrodinger eigenvalue problem (SEP) is used as an initial guess to computing their counterpart of a nonlinear Schrodinger equation (NLS). We discretize the system via centered difference approximations. A predictor-corrector continuation method is exploited as an iterative method to trace solution curves and surfaces of the MCNLS, where the chemical potentials are treated as continuation parameters. The wave func- tions can be easily obtained whenever the solution manifolds are numerically traced. The proposed algorithm has the advantage that it is unnecessary to discretize or integrate the partial derivatives of wave functions. Moreover, the wave functions can be computed for any time scale. Numerical results on the ground-state and excited-state solutions are reported, where the physical properties of the system such as isotropic and nonisotropic trapping potentials, mass conser- vation constraints, and strong and weak repulsive interactions are considered in our numerical experiments.

We present a new implementation of the two-grid method for computing extremum eigenpairs of self-adjoint partial differential operators with periodic boundary conditions. A novel two-grid centered difference method is proposed for the numerical solutions of the nonlinear Schrödinger–Poisson (SP) eigenvalue problem.We solve the Poisson equation to obtain the nonlinear potential for the nonlinear Schrödinger eigenvalue problem, and use the block Lanczos method to compute the first k eigenpairs of the Schrödinger eigenvalue problem until they converge on the coarse grid. Then we perform a few conjugate gradient iterations to solve each symmetric positive definite linear system for the approximate eigenvector on the fine grid. The Rayleigh quotient iteration is exploited to improve the accuracy of the eigenpairs on the fine grid. Our numerical results show how the first few eigenpairs of the Schrödinger eigenvalue problem are affected by the dopant in the Schrödinger–Poisson (SP) system. Moreover, the convergence rate of eigenvalue computations on the fine grid is O(h3).

An X-ray Fabry-Perot resonator has been proposed and investigated for more than three decades. The difficulty in realizing such a resonator is mainly due to the strict requirement on coherence for cavity resonance, which is governed by the energy resolution of the incident X-ray photons and the size of the resonator. With the aid of modern micro-and nanotechnology for silicon, such as X-ray lithography, miniature resonators, approximately a few micrometers or smaller, can be prepared. Together with X-ray photons of ultrahigh-energy resolution from synchrotron sources, the required conditions on coherence for cavity resonance are fulfilled. Several X-ray cavities prepared by this means are used in X-ray back-diffraction experiments, where back diffraction acts as mirror reflection for X rays. Resonance interference fringes are observed unambiguously. Attempts to use multilayered materials for cavity fabrication are discussed in relation to X-ray synchrotron experiment. Possible future applications of this X-ray resonator are also mentioned.

We discuss numerical methods for studying numerical solutions of N-coupled nonlinear Schrödin-ger equations (NCNLS), N = 2, 3. First, we discretize the equations by centered difference approximations. The chemical potentials and the coupling coefficient are treated as continuation parameters. We show how the predictor–corrector continuation method can be exploited to trace solution curves and surfaces of the NCNLS, where the preconditioned Lanczos method with iterative refinement is used as the linear solver. When the chemical potential is large enough, we obtain peak solutions of the NCNLS for certain values of the coupling coefficient. The contours of the peak solutions resemble those of the experimental results of Anglin and Ketterle [2002], and Anderson et al. [1995].

We study the bifurcation scenario of nonlinear Schro¨dinger equations (NLS). The Liapunov-Schmidt reduction is applied to show that the simple bifurcations of a single NLS are pitchfork. The pitchfork bifurcation can be subcritical or supercritical, depending on the coefficient of the cubic term we choose. We also describe numerical methods so that the Liapunov-Schmidt reduction can effectively handle a corank-2 bifurcation point. Next, we apply numerical continuation methods to trace solution curves and surfaces of the NLS, where the system is discretized by the centered difference approximations. Numerical results on two- and three-dimensional $M$-coupled NLS are reported, where the physical properties such as the effect of trapping potentials, isotropic and nonisotropic trapping potentials, mass conservation constraints, and strong and weak repulsive interactions are considered in our numerical experiments.

We report the critical residues for the interaction of the kinins with human bradykinin receptor 1 (B1) using site-directed mutagenesis in conjunction with molecular modeling of the binding modes of the kinins in the homology model of the B1 receptor. Mutation of Lys118 in transmembrane (TM) helix 3, Ala270 in TM6, and Leu294 in TM7 causes a significant decrease in the affinity for the peptide agonists des-Arg10kallidin (KD) and des-Arg9BK but not the peptide antagonist des-Arg10Leu9KD. In contrast, mutations in TM2, TM3, TM6, and TM7 cause a significant decrease in the affinity for both the peptide agonists and the antagonist. These data indicate that the B1 bradykinin binding pocket for agonists and antagonists is similar, but the manners in which they interact with the receptor do not completely overlap. Therefore, there is a potential to influence the receptor's ligand selectivity.

In this paper, we simulate the time evolution of the instantaneous resonant modes (IRMs), which are quasilocalized, in a model of Ga liquid. Through the simulations, we have observed the whole process from creation to annihilation of each individual IRM, and its lifetime is, therefore, estimated. We also find the exchange in character between an IRM and a non-resonant instantaneous normal mode (INM). The exchange occurs as the two INMs have very close frequencies and share a common central particle.

Most popular polishing mechanisms for optical fibre end-face polishing machines are divided into three categories: planetary gear trains, linkages, and programmable logic controllers. To prevent the finished product from being scratched, it is expected that the grinding pattern prevents the lapping surface from repeatedly cutting the optical fibre end face in the same direction during the grinding process. For this reason, a polishing machine, whose grinding pad moves according to a Figure-8 path, is proposed in the present work. A pair of elliptical gears is designed to substitute the anti-parallel four-bar linkage and to drive one point of the coupler link along a Figure-8 pattern. However, owing the kinematic characteristics of elliptical gears, the velocity of the coupler point is highly variable during its motion, which is disadvantageous to the quality of grinding. Thus, in this study, a pair of non-circular gears is proposed as driving mechanism. By providing the driving elliptical gear with a suitable law of motion, it is possible to enable the velocity of the coupler point to be constant. A kinematic simulation has been performed to prove that the use of non-circular gears is effective in improving the motion characteristics of the Figure-8 path of motion, which is generated by elliptical gears.

The interaction of symmetrical lidocaine dimers with voltage-gated Na+ channels (VGSCs) was examined using a FLIPR membrane potential assay and voltage-clamp. The dimers, in which the tertiary amines of the lidocaine moieties are linked by an alkylene chain (two to six methylene units), inhibited VGSC activator-evoked depolarization of cells heterologously-expressing rat (r) Na(v)1.2a, human (h) Na(v)1.5, and rNa(v)1.8, with potencies 10- to 100-fold higher than lidocaine (compound 1). The rank order of potency (C4 (compound 4)C3 (compound 3)or = C2 (compound 2) = C5 (compound 5) = C6 (compound 6)compound 1) was similar at each VGSC. Compound 4 exhibited strong use-dependent inhibition of hNa(v)1.5 with pIC50 values4.5 and 6.0 for tonic and phasic block, respectively. Coincubation with local anesthetics but not tetrodotoxin attenuated compound 4-mediated inhibition of hNa(v)1.5. These data suggest that the compound 4 binding site(s) is identical, or allosterically coupled, to the local anesthetic receptor. The dissociation rate of the dimers from hNa(v)1.5 was dependent upon the linker length, with a rank order of compound 1compound 5 = compound 6compound 2compound 3. The observation that both the potency and dissociation rate of the dimers was dependent upon linker length is consistent with a multivalent interaction at VGSCs. hNa(v)1.5 VGSCs did not recover from inhibition by compound 4. However, "chase" with free local anesthetic site inhibitors increased the rate of dissociation of compound 4. Together, these data support the hypothesis that compound 4 simultaneously occupies two binding sites on VGSCs, both of which can be bound by known local anesthetic site inhibitors.

Development of Taenia saginata asiatica metacestodes in SCID mice, and its infectivity in humans, golden hamsters, and Mongolian gerbils as alternative definitive hosts, were investigated. Cysticerci were recovered from SCID mice that were subcutaneously injected with hatched oncospheres of T. s. asiatica. The morphological changes of metacestodes were observed. The recovered cysticerci were fed to gerbils, hamsters and humans, to check for their infectivity. Tapeworms were recovered from gerbils and hamsters fed with 20 to 45 week-old cysticerci, and proglottids excretions were observed in human volunteers fed with 45 week-old cysticerci. However, no tapeworms were recovered from gerbils fed with 10 week-old cysticerci. Our results suggest that T. s. asiatica oncospheres needed more than 20 weeks to develop to maturity in SCID mice to be infective to both their natural and alternative definitive hosts.

Owing to the complex geometry of helical cutting tools, several manufacturing processes are required to produce the profile of the cutter and the cutting angles. If the traditional method of manufacture were used, the cost would be frustratingly expensive. In this paper, a novel straight-sided hob cutter design consisting of two curved cutting edges and three straight cutting edges with different pressure angles is proposed. By applying designed rake profile equations of a hob cutter, the principle of coordinate transformation, the theory of differential geometry, and the theory of gearing, a mathematical model of the helical cutting tool is derived. In addition, the cutting angles, the condition of full undercutting, and the width of the top land of the cutter are also studied. The novelty of the design is such that the multiangles of the helical cutting tool can be manufactured in one hobbing process, thereby simplifying the manufacturing process. The results and concepts proposed in the paper will be beneficial as design guidance for tool designers, will enhance the manufacturing processes of helical cutting tools, and will assist tool-related industries in upgrading their technology and competitiveness.

We have developed an efficient and selective radioligand, the [35S]-radiolabeled dihydroquinoxalinone derivative, 4, for an ex vivo receptor occupancy assay in transgenic rats over-expressing the human bradykinin B1 receptor.

A characterization of the new Tsing Hua open-pool reactor (THOR) epithermal neutron beam designed for boron neutron capture therapy (BNCT) has been performed. The facility is currently under construction and expected in completion in March 2004. The designed epithermal neutron flux for 1 MW power is 1.7x10(9)n cm(-2)s(-1) in air at the beam exit, accompanied by photon and fast neutron absorbed dose rates of 0.21 and 0.47 mGys(-1), respectively. With (10)B concentrations in normal tissue and tumor of 11.4 and 40 ppm, the calculated advantage depth dose rate to the modified Snyder head phantom is 0.53RBE-Gymin(-1) at the advantage depth of 85 mm, giving an advantage ratio of 4.8. The dose patterns determined by the NCTPlan treatment planning system using the new THOR beam for a patient treated in the Harvard-MIT clinical trial were compared with results of the MITR-II M67 beam. The present study confirms the suitability of the new THOR beam for possible BNCT clinical trials.

The cellular microdosimetry parameters including the cellular S -value and the single-event specific energy distribution for alpha particles and electrons are important in radiation dosimetry and biology. These parameters may be used to determine the relative biological effectiveness of radiations in the boron neutron capture therapy. In the present work, such parameters were calculated for different source to target region combinations, i.e. cell surface, cytoplasm, nucleus and cell. Calculations were made using a semi-analytical model that simulated the emission of alpha particles or electrons by the Monte Carlo method and calculated the energy imparted to the target volume by the analytical method. Delta particle equilibrium and partial delta particle equilibrium were applied to alpha particles and electrons, respectively. Range–energy relations were employed to determine the incident and emerging energies of the primary particles. For electrons, the fraction in the energy loss resulting from the generation of bremsstrahlung and high-energy secondary electrons was estimated. The energy loss straggling of electrons entering and leaving a target volume was also estimated. Calculated cellular S -values were compared to corresponding data of the MIRD Committee. Calculated single-event specific energy distributions were also compared to results calculated using the Penelope code.

We study multigrid methods in the context of continuation methods for reaction–diffusion systems, where the Bi-CGSTAB and GMRES methods are used as the relaxation scheme for the V-cycle, W-cycle and full approximation schemes, respectively. In particular, we apply the results of Brown and Walker [1997] to investigate how the GMRES method can be used to solve nearly singular systems that occur in continuation problems. We show that for the sake of switching branches safely, one would rather solve a perturbed problem near bifurcation points. We propose several multigrid-continuation algorithms for curve-tracking in nonlinear elliptic eigenvalue problems. Our numerical results show that the algorithms proposed have the advantage of being robust and easy to implement.

Theoretically, hob cutters with a straight-sided cutting edge can generate a perfect involute tooth profile. However, due to an unbalanced cutting force, there will be deviation between the actual and the theoretical tooth profile. In this paper, an involute tooth profile manufactured by a hob cutter has been developed based on the theory of even contact. The concept of a shifted cutter was used to correct the tooth profile deviation of involute spur gears.

We study domain decomposition methods for fourth-order plate problems. The well-known von Karman equations are used as our model problem. By exploiting the symmetry of the domain, the solution of the original problem can be obtained by solving those associated reduced problems, which are defined on subdomains with appropriate boundary conditions. We show how nonoverlapping and overlapping domain decomposition methods can be used to solve the reduced problems. For the linearized von Karman equation, we present preconditioners using both Fourier analysis and probing techniques for the interface systems, which are similar to those derived by Chan et al. Finally, we compare the efficiency of various domain decomposition preconditioners for solving the von Karman equations.

We study numerical methods for solving nonlinear elliptic eigenvalue problems which contain folds and bifurcation points. First we present some convergence theory for the MINRES, a variant of the Lanczos method. A multigrid-Lanczos method is then proposed for tracking solution branches of associated discrete problems and detecting singular points along solution branches. The proposed algorithm has the advantage of being robust and can be easily implemented. It can be regarded as a generalization and an improvement of the continuation-Lanczos algorithm. Our numerical results show the efficiency of this algorithm.