objective: the aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in 123i brain spect obtained by the hybrid spect/ct device. methods: we used the 3-dimensional (3d) brain phantom, which imitates the precise structure of gray mater, white matter and bone regions. it was filled with 123i solution (20...

composite pressure vessel cng made of epoxy – carbon material with nonmetal liner is 60% lighter than aluminum vessel under the same conditions. one of the important parameters in the pressure vessels design is their resistance against impact and prevention of explosion. in this paper, the effects of low velocity impact on composite pressure vessel are investigated using fe analysis. the vessel...

spect detects γ-rays from administered radiopharmaceutical within the patient body. γ-rays pass through different tissues before reaching detectors and are attenuated. attenuation can cause artifacts; therefore different methods are used to minimize attenuation effects. in our study efficacy of chang method was evaluated for attenuation purpose, using a custom made heart phantom. due to differe...

SPECT detects γ-rays from administered radiopharmaceutical within the patient body. γ-rays pass through different tissues before reaching detectors and are attenuated. Attenuation can cause artifacts; therefore different methods are used to minimize attenuation effects. In our study efficacy of Chang method was evaluated for attenuation purpose, using a custom made heart phantom. Due to d...

A factorization theorem is proved in the Hardy spaces Hp of the bi-upper half plane, 0 < p ≤ 1. The proof is based on some fundamental work of Chang-Fefferman on atomic decompositions of Hp.

We propose a model of the household where the transmission mechanism between home appliances and women’s labor supply is identical to the one in Greenwood, Seshadri, and Yorukoglu (2005) with one important exception. We explicitly model firms’ pricing and output choices in the appliances sector and thus, the price of home appliances is determined endogenously by the laws of supply and demand ra...

In analogy with the periods of abelian integrals of differentials of the third kind for an elliptic curve defined over a number field, we introduce a notion of periods of the third kind for a rank 2 Drinfeld Fq[t]-module ρ defined over an algebraic function field. In this paper we establish explicit formulae for these periods of the third kind for ρ. Combining with the main result in [Chang-Pap...

Caterpillar compaction NA compaction, say Ryan Case, YunPei Chang, Nicholas Cozzarelli, Carlos Bustamante, and colleagues (University of California, Berkeley, CA), may work via a cooperative caterpillar-like mechanism. The caterpillar is formed by multiple copies of condensin protein—in this case MukBEF—with each V-shaped condensin contributing two legs. Compaction occurs when the caterpillar’s...

In this paper, we describe stratification, a new method of reasoning about discontinuous change . In stratification, we make use of a . family of more detailed model s with a control parameter and predict the outcome of discontinuous change by investigating and summarizing the behavior of a detailed version of a given model in an extreme. Stratification consists of four techniques of : (a) reco...

1389-1286/$ see front matter 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.comnet.2013.08.005 ⇑ Corresponding author. Tel.: +852 62134272. E-mail addresses: [email protected] (P. Zhou), csxluo@ comp.polyu.edu.hk (X. Luo), [email protected] (A. Chen), csrchang@ comp.polyu.edu.hk (R.K.C. Chang). 1 This work was done when the co-author was with The Hong Kong Po...