Electrical Impedance Tomography (EIT), a non-invasive technique used to image the electrical conductivity and permittivity within a body from measurements taken on the body’s surface, could be used as an indicator for breast cancer. Because of the low spatial resolution of EIT, combining it with other modalities may enhance its utility. X-ray mammography, the standard screening technique for breast cancer, is the first choice for that other modality. Here, we describe a radiolucent electrode array that can be attached to the compression plates of a mammography unit enabling EIT and mammography data to be taken simultaneously and inregister. The radiolucent electrode array is made by depositing thin layers of metal on a plastic substrate. The structure of the array is presented along with data showing its X-ray absorbance and electrical properties. The data show that the electrode array has satisfactory radiolucency and sufficiently low resistance.

Engineering analysis of fatigue crack growth depend on different loading conditions, wherever those conditions have been studied, in laboratory or real-world practice. Such analyses can be done on basis of different parameters: the stress intensity factor range, ֵK, introduced in linear elastic fracture mechanics; the J -integral range, ֵJ, employed in elastic-plastic material characterization; the square-root area parameter of Murakami, effective in the presence of small defects and non-metallic inclusions. An alternative presentation of fatigue data has been proposed that uses the crack growth rate against a newly introduced parameter, namely an energy fatigue-function ֵW based at different conditions on different parameters, ֵK or ֵJ or the square-root area parameter of Murakami. This alternative presentation shows fatigue data as forming an almost straight line, which may be termed the “natural fatigue tendency” of a material, and specified more precisely at a given stress range. Also the present study introduces a physical interpretation of the line presentation of fatigue data and some illustrations of the “natural fatigue tendency” for different materials under different conditions.

At this point it should be clear that the principle of virtual work is an integral form of expressing equilibrium, and when we introduce the other two basic requirements to be satisfied, namely, compatibility and the constitutive behavior into the virtual work statement, we have the mathematical model formulated in integral form. It is then called the variational formulation of the problem.

An algorithm is proposed to optimize the performance of a two-phase composite under dynamic loading. The goal is to determine a series of different layouts of the two base materials in a three-dimensional region such that the time-averaged stress energy is minimized. Four cases with different boundary conditions and ratios of mass density are considered and solved numerically. The resulting optimal designs are compared to the static case to illustrate the effect of the dynamic loading. Furthermore, a qualitative comparison is done to indicate the difference between the optimization of eigenfrequencies and the present formulation.

In this paper, a headset with an ear-clip type, transmissive PPG (Photoplethysmography) sensor is presented which allows a continuous and realtime monitoring of the heart rate (HR) whilst listening to music during daily activities. Also, the proposed headset is equipped with a tri-axial accelerometer, which enables the measurement of calorie consumption and step counting. During a variety of daily activities (e.g., walking, jogging, and sleeping etc.), a PPG may be contaminated with motion artifacts. To remove these motion artifacts, we designed an adaptive filter based on the accelerometer.

To evaluate the accuracy of heart rate detection, for 13 subjects the HR from the headset was compared with that detected from the ECG simultaneously recorded with a conventional ECG recorder. As a result, the error rates of the headset are 0.6%, 1.7%, 0.7%, and 5.7% over rest, walking (3km/h), jogging (6 km/h), and running (9km/h), respectively.

From these results, it is likely that the proposed headset shows the performance good enough to be used in the continuous and real-time monitoring of the HR during daily activities. It is expected that the proposed headset is very efficient in the assessment of autonomic nervous activities under various physiological conditions, the exercise monitoring, and the evaluation of physical training performance.

In the last chapter, we discussed how to qualitatively sketch water-surface profiles in channels having gradually varied flows. For engineering applications, however, it is necessary to compute the flow conditions in these flows. These computations, generally referred to as water-surface profile calculations, determine the water-surface elevations along the channel length for a specified discharge. The water-surface elevations are required for the planning, design, and operation of open channels to assess the effects of various engineering works and channel modifications. The addition of a dam, for example, raises water levels upstream of the dam and it is necessary to know the flow depths in the upstream area to determine the extent of flooding.

In addition, steady-state flow conditions are needed to specify proper initial conditions for the computation of unsteady flows. Improper initial conditions introduce false transients into the simulation, which may lead to incorrect results. Unsteady-flow algorithms may be used directly to determine the initial conditions by continuing the computations until the flow conditions become steady. However, such a procedure is computationally inefficient and may not converge to the proper steady-state solution if the finite-difference scheme is not consistent.

In this chapter, methods to compute gradually varied flows are presented. Preference is given to the methods suitable for a computer solution. Two traditional methods – commonly referred to as the direct and standard step methods – are first presented. The computations progress step by step from one section to the next in these methods. Then, numerical methods to integrate the governing differential equation are introduced. A procedure is then presented that computes the flow conditions at all specified locations of a channel system simultaneously instead of computing them from one section to the next.

This paper describes why thek-dimension maximal oriented energy subspace of the measurable voltage-change matrix is the optimal feature to locate faults in a population of circuits. The paper elaborately designs a “nearness” concept, which is used to construct a fault candidate set in a small size, and proposes a maximal nearness criterion. On the basis of these, the paper presents a novel algorithm to efficiently improve the accuracy and speed of fault locating.