Review and classification of reliability measures for multistate and continuum models

In this paper we examine a variety of customer-centered reliability measures, generalized to multistate and continuum contexts. A classification scheme is proposed for these measures, and a new measure based on customer-usage patterns is defined. In each case, reliability measures are defined such that they are equally valid for binary, multistate, continuum, and mixed systems. Techniques which facilitate the use of continuum models are discussed, and time-dynamic, infinite-time, and partial-information modeling considerations are also addressed.     

Letter of Congatutulation

正I take great pleasure in congratulating CHINA FOUNDRY journal on its 10th anniversary.The CHINA FOUNDRY journal started ten years ago.Since its inaugural,China has seen exceptional growth in the Castings Sector and rapid development in Machinery Industry.The journal is becoming an important communication platform for experts     

Stability,controllability and observability of the pulmonary circulatory system via its modified modelling

Pulmonary circulatory system is analytically studied in this paper. Tho existing model of the circulation process is modified by introducing an inertance element in the system determining the right ventricular dynamics. The value of the inertance is estimated by applying control theory. The stability, controllability and observability uf the system having this modified rnodol are studied. It is found that this process is always stable, completely controllable and also observable.     

Some replacement policies with minimal repairs and repair cost limit

Some extended replacement policies based on the number of failures, incorporating the concept of repair cost limit are discussed. Three models are considered as follows: (a) a unit is replaced at the nth failure, or when the estimated minimal repair cost exceeds a particular limit c; (b) a unit has two types of failures and is replaced at the nth type 1 failure, or type 2 failure, or when the estimated repair cost of type 1 failures exceeds a predetermined limit c—type 1 failures are minimal; failures, type 2 failures are catastrophic failures and both occur with constant probability; (c) a unit has two types of failures and the type 1 and type 2 failures are age dependent—the unit is replaced at the nth type 1 failure, type 2 failure, or when the estimated repair cost due to type 1 failures exceeds a predetermined limit c. Introducing costs due to replacements, inspections, and minimal repairs, an optimal number of minimal repairs before replacement is obtained, which minimizes the expected cost rate. Some particular cases are also derived. Finally, the application of these models to computer science is discussed.     

Kinetics of Solid-State Reactions of Particulate Ensembles with Size Distributions

Rate equations for solid-state reactions of monosized spheres cannot be applied directly to particulate ensembles with a distribution of sizes, such as are frequently encountered in practice. A method using experimental data for the overall extent of reaction as a function of time is proposed for identification of the reaction mechanism and computation of the rate constant and activation energy when the particle-size spectrum of the starting material is known. The method, which is based on comparison of the characteristic paths of the assumed reaction mechanisms with experimental data, may be applied to a wide range of solid-state kinetic models.     

DYNAMIC VISCOELASTIC PROPERTIES OF PASTA AS A FUNCTION OF TEMPERATURE AND WATER CONTENT*

Pasta samples were tested in the linear viscoelasticity range using a dynamic mechanical thermal analyzer over the temperature range of 25 to 95C and the water content range of 12 to 20% (weight of water/weight of solids). To obtain wholesome pasta samples at different moisture levels, the intermittent sorption technique was used. The behavior of G′ and tanδversus temperature curves exhibited a transition, which was determined to be the glass transition by making comparisons to the literature values of glass transition for starch and semolina extrudates. At 12.5% water content, glass transition initiated at 48.7C. With increase in water content values, the initiating glass transition temperature decreased. At 19.7% water content, glass transition was observed in the temperature range of 36.9 to 57.3C. Although pasta contains about 13% protein fraction, it did not seem to affect the major part of glass transition range because the pasta proteins become mobile at temperatures greater than 80C and water content greater than 17%.     

LETTER OF CONGRATULATION

I take great pleasure in congratulating CHINA FOUNDRY journal on its 10th anniversary. The CHINA FOUNDRY journal started ten years ago. Since its inaugural, China has seen exceptional growth in the Castings Sector and rapid development in Machinery Industry. The journal is becoming an important communication platform for experts and scholars in the foundry field. After a decade of development, CHINA FOUNDRY has become one of the most influential casting technology journals in the world. It has played a vital role in promoting technical exchange and cooperation between Chinese and International foundry industries. To have such a highly regarded journal is truthfully a resource to reward.     

Dry Strength of Pelletized Spheres

Three limestone powders, differing only in specific surface area, were agglomerated in a balling drum to form pellets of various sizes. The pellets were tested for dry compressive strength at different rates of deformation. A limiting elastic energy criterion for failure was used to derive the relation (analogous to the classical Hertz relation for strength of an elastic isotropic sphere) between the pellet size, the total deformation, and the load at failure. The surface area of the powder, the porosity of the pellet, and its compressive strength are analytically related; the results are in good agreement with the experimental data.     

Analog domain adaptive equalizer for low power 40 Gbps DP-QPSK receivers

Electrical domain equalization of chromatic and polarization mode dispersion is attractive in coherent optical communication links. Digital coherent receivers used for this purpose are based on high speed ADCs followed by DSP, which dissipate excessive amount of power and are very costly to implement. We propose analog coherent receiver to drastically reduce the power consumption, size and cost. An adaptive feed forward equalizer for 40 Gbps dual polarization quadrature phase shift keying (DP-QPSK) systems, which processes signals in analog domain itself, is demonstrated using circuit and system simulations. The equalizer, designed in 90 nm CMOS technology, consumes 450 mW of power and occupies 1.8 mm × 1.1 mm chip area. System simulations are used to show that blind equalization is also possible when this approach is used in decision directed mode.