Application of Support Vector Machines in Assessing Conceptual Cost Estimates

Total conceptual cost estimates and the assessment of the quality of these estimates are critical in the early stages of a building construction project. In this study, the support vector machine (SVM) model for assessing the quality of conceptual cost estimates is proposed, and the application of SVM in construction areas is investigated. The results show that the SVM model assessed the quality of conceptual cost estimates slightly more accurately than the discriminant analysis model. This shows that using the SVM has potential in construction areas. In addition, the SVM model can assist clients in their evaluation of the quality of the estimated cost and the probability of exceeding the target cost, and in their decision on whether or not it is necessary to seek a more accurate estimate in the early stages of a project.     

An effective rhodium catalyst system on the synthesis of acetic acid from methyl formate

Rh/Lil/SnR₄ is an effective catalyst system for the conversion of methyl formate to acetic acid under carbon monoxide pressure. The effects of solvent and initial CO partial pressure on the turnover rate of the reaction were investigated. The possibility of replacing some of the iodide promoters by tin compounds has been probed.     

HYDRODYNAMIC FORCE ON SMOOTH HORIZONTAL CYLINDER IN UNIFORM OSCILLATORY FLOW

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Peptide YY inhibition of rat gastric enterochromaffin-like cell function

The present study determined tumorigenicity, tumor classification and DNA damage induced in infant mice by benzo[a]pyrene (B[a]P) or Manufactured Gas Plant (MGP) residues after a single exposure. Male and female B6C3F1 mice were exposed to B[a]P or MGP residue from a single environmental site (MGP-4) and males were also exposed to MGP residue composite from seven different sites (MGP-M7). At 26, 39 and 52 weeks after exposure tumorigenesis was assessed in lung, forestomach and liver. Formation and persistence of DNA adducts were quantified by 32P-postlabeling. Exposure of males to B[a]P induced liver tumors in a dose and time dependent manner. MGP induced more advanced tumors than B[a]P. Only a single liver tumor was found in MGP-4 treated females. No forestomach and few pulmonary adenomas were induced in males or females. MGP-4, MGP-M7 or B[a]P induced DNA adducts in males and females. Adducts in liver, lung and forestomach peaked on different days and decreased at different rates. At 24 h post-exposure, no significant differences in initial DNA adduct levels occurred in males and females exposed to MGP-4 or B[a]P. Lack of DNA damage (adducted DNA) did not account for non-responsiveness of lung and forestomach in B6C3F1 genders as well as in liver in females. MGP tumorigenicity could not be accounted for solely by B[a]P content nor did it reflect additivity of B[a]P and other carcinogenic polycyclic aromatic hydrocarbons (PAHs) in MGP. Synergy among MGP-PAHs, presence of unidentified carcinogens and/or promoters in MGP may account for MGP potency. The B6C3F1 infant male model is a convenient and rapid assay for assessing MGP liver tumorigenicity and potency.     

Ultralow-voltage boron-doped diamond field emitter vacuum diode

A boron-doped diamond field emitter diode with ultralow turn-on voltage and high emission current is reported. The diamond field emitter diode structure with a built-in cap was fabricated using molds and electrostatic bonding techniques. The emission current versus anode voltage of the capped diamond emitter diode with boron doping, sp² content, and vacuum thermal electric (VTE) treatment shows a very low turn-on voltage of 2 V. A high emission current of 1 μA at an anode voltage of less than 10 V can be obtained from a single diamond tip. The turn-on voltage is significantly lower than comparable silicon field emitters     

Accuracy of using computed tomography to identify pedicle screw placement in cadaveric human lumbar spine

STUDY DESIGN: Utility of using computed tomography to predict pedicle screw misplacement. OBJECTIVE: This study defines the sensitivity and specificity of predicting pedicle screw placement by experienced clinicians using a CT scan image. SUMMARY OF BACKGROUND DATA: In clinical and research settings, the method most commonly used to evaluate pedicle screws placement has been computed tomography. However, no current literature describes the accuracy of this method of evaluating screw placement. METHOD: Cobalt-chrome and titanium alloy pedicle screws of identical size were placed in six cadaveric human lumbar spine. Wide laminectomy was performed to allow complete visualization of the pedicles. Three consecutive lumbar levels were instrumented in each spine, giving 36 pedicle screw placements to identify. The instrumented spines were imaged, and four orthopaedic spine surgeons and a musculoskeletal radiologist were asked to read the images to identify the accuracy of screw placement within the pedicles. RESULTS: The sensitivity rate of identifying a misplaced screw was 67 +/- 6% for cobalt-chrome screws compared with 86 +/- 5% for titanium screws (P < 0.005). The specificity rates of radiographic diagnosis of misplaced pedicle screws were 66 +/- 10% for cobalt-chrome screws and 88 +/- 8% for titanium screws (P < 0.005). Similarly, a statistically significant difference was found in the sensitivity rates of identifying screws placed correctly in the pedicle: 70 +/- 10% for cobalt-chrome screws versus 89 +/- 8% for titanium screws (P < 0.005). Overall accuracy rates were 68 +/- 7% for cobalt chrome screws versus 87 +/- 3% for titanium screws (P < 0.002). CONCLUSION: Reliance on the computed tomography scan data alone in determining accuracy of pedicle screws can lead to inaccuracies in both clinical and research conditions.     

The role of glutathione in dopaminergic neuronal survival

An increased production of reactive oxygen species is thought to be critical to the pathogenesis of Parkinson's disease. At autopsy, patients with either presymptomatic or symptomatic Parkinson's disease have a decreased level of glutathione in the substantia nigra pars compacta. This change represents the earliest index of oxidative stress in Parkinson's disease discovered to this point. This study compares the sensitivity of dopaminergic and nondopaminergic neurons in dissociated mesencephalic cultures to the depletion of glutathione. We have found that dopaminergic neurons are more resistant to the toxicity of glutathione depletion than nondopaminergic neurons. The possibility that dopaminergic neurons have a higher baseline glutathione level than nondopaminergic neurons is suggested by measurements of levels of cellular glutathione in a parallel system of immortalized embryonic dopaminergic and nondopaminergic cell lines. We also examined the role of glutathione in 1-methyl-4-phenylpyridinium toxicity. Decreasing the glutathione level of dopaminergic neurons potentiates their susceptibility to 1-methyl-4-phenylpyridinium toxicity, although 1-methyl-4-phenylpyridinium does not deplete glutathione from primary mesencephalic cultures. Our data suggest that although a decreased glutathione content is not likely to be the sole cause of dopaminergic neuronal loss in Parkinson's disease, decreased glutathione content may act in conjunction with other factors such as 1-methyl-4-phenylpyridinium to cause the selective death of dopaminergic neurons.     

Matrix unit cell scheduler (MUCS) for input-buffered ATM switches

This paper presents a novel matrix unit cell scheduler (MUCS) for input-buffered asynchronous transfer mode (ATM) switches. The MUCS concept originates from a heuristic strategy that leads to an optimal solution for cell scheduling. Numerical analysis indicates that input-buffered ATM switches scheduled by MUCS can utilize nearly 100% of the available link bandwidth. A transistor-level MUCS circuit has been designed and verified using HSPICE. The circuit features a regular structure, minimal interconnects, and a low transistor count. HSPICE simulation indicates that using 2-μm CMOS technology, the MUCS circuit can operate at clock frequency of 100 MHz     

Statistical estimation of average power dissipation usingnonparametric techniques

In this paper, we present a new statistical technique for estimation of average power dissipation in digital circuits. The present parametric statistical technique estimates the average power based on the assumption that the power distribution can be characterized by a preassumed function. Large error can incur when the assumption is not met. On the other hand, the existing nonparametric technique, although accurate, is too conservative and requires a large sample size in order to achieve convergence. For a good tradeoff between simulation accuracy and computational efficiency, we propose a new nonparametric technique using the properties of the order statistics. It is generally applicable to any type of circuit irrespective of its power distribution function. Compared to the existing nonparametric technique, it is much more computationally efficient since it requires a much smaller sample size to achieve the same accuracy specification. This new technique is implemented in the distribution-independent power estimation tool (DIPE). DIPE is empirically demonstrated to be more robust and accurate than the parametric technique     

Interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd0.96Zn0.04 Te (211)B substrates by molecular beam epitaxy

Double-crystal x-ray rocking curve (DCRC) and secondary-ion mass-spectroscopy (SIMS) measurements have been performed to investigate the effect of rapid thermal annealing on the interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd_0.96Zn_0.04Te (211)B substrates by molecular beam epitaxy. The sharp satellite peaks of the DCRC measurements on a 100-period HgTe/CdTe (100Å/100Å) superlattice show a periodic arrangement of the superlattice with high-quality interfaces. The negative direction of the entropy change obtained from the diffusion coefficients as a function of the reciprocal of the temperature after RTA indicates that the Hg diffusion for the annealed HgTe/CdTe superlattice is caused by an interstitial mechanism. The Cd and the Hg concentration profiles near the annealed HgTe/CdTe superlattice interfaces, as measured by SIMS, show a nonlinear behavior for Hg, originating from the interstitial diffusion mechanism of the Hg composition. These results indicate that a nonlinear interdiffusion behavior is dominant for HgTe/CdTe superlattices annealed at 190°C and that the rectangular shape of HgTe/CdTe superlattices may change to a parabolic shape because of the intermixing of Hg and Cd due to the thermal treatment.