Two specially designed plastic/aluminum phantoms positioned thermoluminescent dosimeters (TLDs) at the right and left breast location of an anthrophomorophic chest torso. Imaging was performed on a spiral CT for a Volume of the chest phantom through the breast area for a noncontiguous (pitch 1.5) helical chest scan. Conventional pencil beam ionization chamber measurements were made at the same ...

Hydroxyapatite bioceramic was used for the manufacture of an orbital floor prosthesis from spiral CT data acquired transaxially at 1-mm beam collimation, pitch of 1, and 0.2-mm reconstruction intervals. CT data were converted to vector file format for subsequent prosthesis manufacture on a stereo-lithography machine. The orbital floor prosthesis was engrafted onto an acrylic model of the orbit ...

Tough pitch copper wire (99.97% Cu) is generally characterized by the spiral elongation number. The principle of the test is based on the influence of impurities on the recrystallization kinetics. Alternative non-metallographic techniques to characterize the recrystallization kinetics have been investigated in this study, such as differential scanning calorimetry (D.S.C.) and residual electrica...

This paper explores the possibilities of very simple analysis on derivation of spiral regions for a single segment of cubic function matching positional, tangential, and curvature end conditions. Spirals are curves of monotone curvature with constant sign and have the potential advantage that the minimum and maximum curvature exists at their end points. Therefore, spirals are free from singular...

A new approach based on vector field clustering for tool path optimization of 5-axis CNC machining is presented in this paper. The strategy of the approach is to produce an efficient tool path with respect to the optimal cutting direction vector field. The optimal cutting direction maximizes the machining strip width. We use the normalized cut clustering technique to partition the vector field ...

In this paper, a method with sentence-wide optimization consideration is proposed to generate a Mandarin sentence's pitch-contour. The developed model is called the sentence pitch-contour HMM (SPC-HMM) due to its use of VQ (vector quantization) and HMM (hidden Markov model). To construct an SPC-HMM, the pitch-contours of the syllables from each training sentence are normalized on both time and ...

A full Steiner tree T for a given set of points P is defined to be linear if all Steiner points lie on one path called the trunk of T . A (nonfull) Steiner tree is linear if it is a degeneracy of a full linear Steiner tree. Suppose P is a simple polygonal line. Roughly speaking, T is similar to P if its trunk turns to the left or right when P does. P is a left-turn (or right-turn) polygonal spi...

A substrate surface on which gold particles are distributed is prepared by annealing an ultra-thin gold film to enable glancing angle deposition. By cooling the substrate and controlling its spin rate, two spiral-like and one screw-like gold nanohelix arrays are grown upon the seeded surfaces. The mean helix radius and pitch length are reduced to 17 and 55 nm, respectively. The g-factor of the ...