An Integrated Refinement and Testing Method for Stream X-machines

 Over the last decade, stream X-machines have been used in order to specify a range of systems. One of the strengths of this approach is that, under certain well defined conditions, it is possible to produce a test set that is guaranteed to determine the correctness of the implementation under test. However, if X-machines are to be used in practice as a tool for specification and test generation, there needs to be ways of developing existing specifications into more complex and more detailed versions through a process of refinement. Associated with the refinement of the specification, there needs to be methods of refining the corresponding test sets, that is to construct the test set in parallel with the specification and to distribute the testing into smaller chunks, with major cost and time savings. A few such specification and testing refinements of X-machine have already been investigated. This paper introduces a new type of X-machine refinement, called simple covering, which expands the input-output behaviour of an existing X-machine. Associated with this process, the corresponding refinement of the test set is described and a method of testing X-machines constructed as simple coverings is developed. Received: March 29, 2000; revised version: December 2, 2001     

Heat transfer in flow over straight transverse fins

An experimental investigation has been made of heat transfer in a large-scale model of a channel with fins transverse to a gas stream. Distributions of local heat transfer coefficient over fin height have been obtained as a function of the geometrical characteristics and the Re number, and from these data correction coefficients have been computed for the effectiveness of the fins, taking account of the nonuniformity of the distribution of over fin height.     

A Bayesian Approach to Obtain a Lower Bound for the Cpm Capability Index

The Taguchi capability index C_pm, which incorporates the departure of the process mean from the target value, has been proposed to the manufacturing industry for measuring manufacturing capability. A Bayesian procedure has been considered for testing process performance assuming , which was generalized without assuming . Statistical properties of the natural estimator of the index C_pm for normal processes have been investigated extensively. However, the investigation was restricted to processes with symmetric tolerances. Recently, a generalized C_pm, referred to as , was proposed to cover processes with asymmetric tolerances. Under the normality assumption, the statistical properties of the estimated including the exact sampling distribution, the rth moment, expected value, variance, and the mean‐squared error were obtained. In this paper, we use a Bayesian approach to obtain the interval estimation for the generalized Taguchi capability index . Consequently, the manufacturing capability testing can be performed for quality assurance. Copyright © 2005 John Wiley & Sons, Ltd.     

Particle processing technology

In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing[1 Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar]3 Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [Google Scholar]].

This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si₃N₄-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also includes two papers on the fabrication of mechanically reliable nanocomposites by dispersing graphene into a ceramic matrix, and on supercapacitors with high energy densities in a Co(OH)₂ system decorated with graphene and carbon nanotubes. As a novel preparation method of oxide films, the fabrication of alumina films with laminated structures by ac anodization is reviewed. Moreover a new type of nanosheet has been fabricated by the exfoliation of layered, ternary transition-metal carbide and nitride compounds, known as Mn 1 Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar]1 Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar]AXn phases (or MAX phases) where M is an early transition metal, such as Ti or Nb, A is an A group element, such as Si or Al, X is carbon and or nitrogen and n 1 Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar]1 Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar]3 Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [Google Scholar][4] Naguib M, Mashtalir O, Carle J, Presser V, Lu J, Hultman L, Gogotsi Y and Barsoum M W 2012 ACS Nano 6 1322 [Google Scholar]. Among the MAX phases, those containing Mo have been theoretically calculated by first-principles calculations to be a source for obtaining Mo₂C nanosheets with potentially unique properties. As an example of improving bulk ceramic properties, texturing by using a high magnetic field[5] Sakka Y and Suzuki T S 2005 J. Ceram. Soc. Japan 113 26 [Google Scholar] and sintering by the electric current activated/assisted sintering (ECAS) technology[6] Grasso S, Sakka Y and Maizza G 2009 Sci. Technol. Adv. Mater. 10 053001 [Google Scholar] have been demonstrated for ultra-high temperature ceramics with high-temperature strength.

A project on the development of materials and particle processing for the field of environment and energy has been ongoing at the National Institute for Materials Science since April 2011. This project employs various core competence technologies for particle processing such as ion beam irradiation for nanoparticle fabrication[7] Nakao H, Tokonami S, Hamada T, Shiigi H, Nagaoka T, Iwate F and Takeda Y 2012 Nanoscale 4 6814 [Google Scholar], fullerene nanomaterial processing using liquidliquid interface precipitation[8] Miyazawa K and Hotta K 2010 J. Cryst. Growth 312 2764 [Google Scholar], a gas reduction nitridation process to obtain Si₃N₄-based phosphor materials[9] Suehiro T, Xie R and Hirosaki N 2013 Indust. Eng. Chem. Res. 52 7453 [Google Scholar], advanced phosphors via novel processing[10, 11] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar], ultra-high pressure technology for processing and in situ analysis[12 Kawamura F, Yusa H and Taniguchi T 2012 Appl. Phys. Lett. 100 251910 [Google Scholar], 13] Watanabe K and Taniguchi T 2011 Int. J. Appl. Ceram. Technol. 8 977 [Google Scholar], colloidal processing in a high magnetic field to obtain laminated, textured ceramics[1, Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar] 3, Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [Google Scholar] 5] Sakka Y and Suzuki T S 2005 J. Ceram. Soc. Japan 113 26 [Google Scholar], the ECAS process for nanostructuring ceramics[6] Grasso S, Sakka Y and Maizza G 2009 Sci. Technol. Adv. Mater. 10 053001 [Google Scholar] and so forth. Here, I would like to introduce some research achievements that are not covered in this special issue.

(1) The evolution of hydrogen by the reaction of fine metal particles such as Al[14] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar] and Mg[15] Uda M, Okuyama H, Suzuki T S and Sakka Y 2012 Sci. Technol. Adv. Mater. 13 025009 [Google Scholar] with water; the specific surface area and surface modification are important factors.

(2) The realization of new carbon related materials with 1D and 2D structures consisting of fullerenes prepared by liquid liquid interface precipitation: alkaline-doped superconductive nanotubes consisting of fullerenes[16] Takeya H, Kato R, Wakahara T, Miyazawa K, Yamaguchi T, Ozaki T, Okazaki H and Takano Y 2013 Mater. Res. Bull. 48 343 [Google Scholar], application to solar cells of fullerene/cobalt porphyrin hybrid nanosheets[17] Wakahara T, D Angelo P, Miyazawa K, Nemoto Y, Ito O, Tanigaki N, Bradley D D C and Anthopoulos T D 2012 J. Am. Chem. Soc. 134 7204 [Google Scholar], etc.

(3) The fabrication of textured films and bulk materials with excellent functional properties by colloidal processing methods such as slip casting[5] Sakka Y and Suzuki T S 2005 J. Ceram. Soc. Japan 113 26 [Google Scholar], gel casting[18] Wiecinska P, Sakka Y, Suzuki T S, Uchikoshi T, Mizerski T and Szafran M 2013 J. Ceram. Soc. Japan 121 89 [Google Scholar] and electrophoretic deposition[3, Sakka Y and Uchikoshi T 2010 KONA Powder Particle J. 28 74 (kona.or.jp/search/28_074.pdf) [Google Scholar] 19] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar], in a high magnetic field, and with subsequent heating; examples of such materials include dye-sensitized TiO₂ solar cells, thermoelectric materials and cathode materials for solid state Li-ion batteries and dielectric ceramics.

(4) The fabrication of high-strength and high-toughness MAX phase ceramics[20 Hu C, Sakka Y, Grasso S, Nishimura T, Guo S and Tanaka H 2011 Scr. Mater. 64 765 [Google Scholar], 21] Hu C, Sakka Y, Nishimura T, Guo S, Grasso S and Tanaka H 2011 Sci. Technol. Adv. Mater. 12 044603 [Google Scholar] inspired by the nacreous structure[22] Kakisawa H and Sumitomo T 2011 Sci. Technol. Adv. Mater. 12 064710 [Google Scholar].

(5) The modeling and development of the ECAS process[6] Grasso S, Sakka Y and Maizza G 2009 Sci. Technol. Adv. Mater. 10 053001 [Google Scholar]. This involves two-step pressure application[23] Grasso S, Hu C F, Maizza G, Kim B N and Sakka Y 2011 J. Am. Ceram. Soc. 94 1405 [Google Scholar] and high-pressure application above 400 MPa to fabricate transparent oxides[24 Grasso S, Kim B N, Hu C F, Maizza G and Sakka Y 2010 J. Am. Ceram. Soc. 93 2460 [Google Scholar]26] Kim B-N, Hiraga K, Grasso S, Morita K, Yoshida H, Zhang H and Sakka Y 2012 J. Ceram. Soc. Japan 120 116 [Google Scholar], and rapid heating to obtain dense nanocomposites of ceramic–CNT[27] Estili M, Kawasaki A and Sakka Y 2012 Adv. Mater. 24 4322 [Google Scholar] and diamonds[28] Grasso S, Hu C F, Maizza G and Sakka Y 2012 J. Am. Ceram. Soc. 95 2423 [Google Scholar].

(6) The contraction of ternary phase diagrams for oxide ion conductor systems such as zirconia[29] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar] and apatite systems[30] Sakka Y 2006 J. Ceram. Soc. Japan 114 371 [Google Scholar], leading to an increased understanding of the stability of such systems and assisting the search for high oxygen ion conductors.     

Measuring production yield for processes with multiple quality characteristics

Process yield is an important criterion used in the manufacturing industry for measuring process performance. Methods for measuring yield for processes with single characteristic have been investigated extensively. However, methods for measuring yield for processes with multiple characteristics have been comparatively neglected. In this paper, we develop a generalized yield index, called TS _pk,PC , based on the index S_pk introduced by Boyles (Journal of Quality Technology, 23, 17–26, 1991 Boyles, RA. 1991. The Taguchi capability index. J. Qual. Technol., 23: 17–26. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) using the principal component analysis (PCA) technique. We obtained a lower confidence bound (LCB) for the true process yield. The proposed method can be used to determine whether a process meets the preset yield requirement, and make reliable decisions. Examples are provided to demonstrate the proposed methodology.     

Spin correlations for an Anderson impurity in conventional and unconventional superconductors

We present a theoretical study of the spin-spin correlation functionC(r) in a superconductor, whereC(r) = S · s(r);S is an impurity spin operator, ands(r) is the conduction electron spin density operator. We model the impurity using the Anderson Hamiltonian, and use the U , 1/N expansion to do the calculations. In addition to conventional superconductors, we consider unconventional superconductors, in which the order parameter (k) has a lower rotational symmetry, and has vanishing angular average. Of particular interest is the way that the behavior ofC(r) reflects two length scales, the Kondo length _k and the superconducting coherence length, ₀, and the way that its behavior is affected by the angular dependence of unconventional gaps.     

Integrated model for determining the optimal initial settings of the process mean and the optimal production run assuming quadratic loss functions

Chen and Chung (1996 Chen, SL and Chung, KJ. 1996. Determining the optimal production run and the most profitable process mean for a production process. International Journal of Production Research, 34: 2051–2058.  ) addressed the problem of the joint determination of the optimal process mean and production run for an industrial process. Their study considered a product with an upper and a lower specification limit. The optimal process mean and optimal production run were obtained by balancing the profit of meeting and not meeting the specification limits. However, Chen and Chung did not consider the quality cost for the product within the specification limits. The present paper revisits the problem and incorporates the quality cost by introducing a Taguchi loss function for determining simultaneously the optimal process mean and production run. As per Chen and Chung, the present paper assumes a 100% inspection scheme. It also investigates the differences between Chen and Chung's approach and the Reward Theorem approach. A sample inspection scheme is also proposed. Numerical examples are provided to demonstrate the application of the model. A sensitivity analysis of the model is provided. Some new directions for further research are also outlined.     

Correction to the formula for the London moment of a rotating superconductor

This paper gives a full quantum mechanical analysis of the magnetic field (first discussed by London) that appears spontaneously when a sample of superconductor is set into rotation. It is shown that, for slow rotation velocities and using certain approximations, the fieldB threading a cavity within a superconductor that rotates at angular velocity is given bye B=2(m _o–W/c ²), where — e is the charge on the electron,m _o is the free electron mass,W is the work function of the superconductor, andc is the velocity of light. In this calculation effects that are second order in the rotation velocity have been ignored, and the result is only strictly valid at the zero of temperature. The application of this result to experiments using practical, nonideal apparatus is then illustrated for a simple geometry.This work was supported in turn by the Science Research Council; Trinity College, Cambridge; and the U. S. Department of Commerce under contract number NB81RAC10026.     

Comments on: An updated review of Goodness-of-Fit tests for regression models

We discuss the following two particular aspects of the paper of González-Manteiga and Crujeiras (10.1007/s11749-013-0327-5): First, what changes if the null hypothesis is non- or semiparametric? For example, Rodriguez-Poo et al. (A practical test for misspecification in regression: functional form, separability, and distribution. Econom. Theory, 2013, under revision) considered optimal rates of adaptive nonparametric tests when the null model is semiparametric. A second, though related question is, how serious are the bandwidth and calibration problems? Sperlich (On the choice of regularization parameters in specification testing: a critical discussion. Empir. Econ., 2013, forthcoming) has shown that the unsolved bandwidth selection problems, in particular when calibrating, render nonparametric specification tests useless in practice. Two additional questions are only raised briefly and concern (a) the computational aspects, and (b) the problem that asymptotically, nonparametric omnibus tests might reject almost any null hypothesis as probably no parametric or semiparametric model is 100 % correct. But it is maybe a reasonable and useful approximation. To this aim we recall the idea of testing the problem of so-called ‘precise hypotheses’ as outlined in Dette (Ann. Stat. 27:1012–1040, 1999) for nonparametric goodness-of-fit tests.