610 research outputs found
Characterization and Simulation of p-Type Ion Implantation in MCT
Ion implantation is one of the key technologies for the fabrication of HgCdTe (MCT) infrared photodiodes. In order to achieve p-on-n type photodiode structure with better performance, the group V elements typically serve as p-type dopants, especially arsenic. In this chapter, ion profiles, defect microstructures, and surface amorphization of implanted group V dopants represented by arsenic into MCT epilayers were characterized by secondary ion mass spectroscopy (SIMS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), respectively. The influences of some significant technological parameters related to ion implantation, such as implant energy, implant dose, ion beam current, barrier layer structure, on the distributions of ions and induced damages are analyzed. In addition, the high-temperature annealing used to eliminate induced damages and activate the electrical activity of ions was subjected to the as-implanted samples, and the ion diffusion profiles and surface microstructures were acquired and analyzed. Finally, the computer simulations on the collision of incident ions and lattice atoms were carried out to study the distributions of ions and recoil atoms numerically. The simulation results are in good agreement with the experimental data
Complexity of Construction Mega Infrastructure Project
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A direct optimization method for low group delay FIR filter design
This paper studies the design of FIR filter with low group delay, where the desired phase response is not being approximated. It is formulated as a constrained optimization problem, which is then solved globally. Numerical experiments show that our design method can produce a filter with smaller group delay than that obtained by the existing convex optimization method used in conjunction with a minimum phase spectral factorization method under the same design criteria. Furthermore, our formulation offers us the flexibility for the trade-off between the group delay and the magnitude response directly. It also allows the feasibility of imposing constraints on the group delay
Multi-criterion two-sided matching of Public-Private Partnership infrastructure projects: Criteria and methods
Two kinds of evaluative criteria are associated with Public-Private Partnership (PPP) infrastructure projects, i.e., private evaluative criteria and public evaluative criteria. These evaluative criteria are inversely related, that is, the higher the public benefits; the lower the private surplus. To balance evaluative criteria in the Two-Sided Matching (TSM) decision, this paper develops a quantitative matching decision model to select an optimal matching scheme for PPP infrastructure projects based on the Hesitant Fuzzy Set (HFS) under unknown evaluative criterion weights. In the model, HFS is introduced to describe values of the evaluative criteria and multi-criterion information is fully considered given by groups. The optimal model is built and solved by maximizing the whole deviation of each criterion so that the evaluative criterion weights are determined objectively. Then, the match-degree of the two sides is calculated and a multi-objective optimization model is introduced to select an optimal matching scheme v ia a min-max approach. The results provide new insights and implications of the influence on evaluative criteria in the TSM decision
Clinical Distribution and Drug Resistance of 224 Strains of Pseudomonas Aeruginosa
Objective: To provide evidence for a rational and effective prevention and treatment of Pseudomonas aeruginosa, the clinical characteristics and the resistance to various antibiotics of were investigated.Methods:A retrospective analysis of 224 strains of Pseudomonas aeruginosa isolated from various specimens from various clinical departments of our hospital (April 1, 2018 to June 31, 2019) were conducted. Identification and drug susceptibility test of isolated strains was performed using a fully automatic bacterial identification analyzer (MicroScan WalkAway-96 plus), and data analysis was performed using WH0NET5.6 software. Result:Among all the bacteria isolated in our hospital during the above period, Pseudomonas aeruginosa accounted for 10.09% of them all and 12.57% of Gram-negative bacilli, respectively. These isolates were mainly derived from sputum specimens (68.75%), mainly from male patients (70.54%), and mostly 61-70 (27.23%) or 51-60 (22.77%) years old. Pseudomonas aeruginosa isolates are mainly from Rehabilitation Ward, ICU, and Liver Transplantation Unit, accounted for 29.91%, 12.95% and 10.27% of all isolates, respectively. The sensitivity of Pseudomonas aeruginosa to various antibacterial drugs, in the order of high to low were carbapenems, aztreonam, quinolones, cephalosporins, piperacillin/ tazobactam, aminoglycoside, with a lowest resistance rate (2.4%) to amikacin and a highest resistance rate to imipenem (33.0%). Conclusion:The isolation rate of Pseudomonas aeruginosa was relatively stable during the study period, and among all the P. aeruginosa detected, most of them were from the respiratory secretions of elderly male patients. The resistance rate of Pseudomonas aeruginosa isolates to various antibiotics is mainly within 30%. Clinical units such as Rehabilitation Ward, ICU, and Liver Transplantation Unit have a high detection rate, therefore, these departments should be monitored in a focused manner. Our research provide a scientific basis for the rational use of antibiotics and a better control of Pseudomonas aeruginosa infection
Bidding Strategy to Support Decision-Making Based on Comprehensive Information in Construction Projects
© 2016 Ru Liang et al. This paper develops a unified method to support contractor for bidding selection in construction projects. A cross-functional contractor with 28 candidate units distributed in the three departments (construction units, design units, and suppliers) is used as an example. This problem is first formulated as a 0-1 quadratic programming problem through optimizing individual performance and collaborative performance of the candidate units based on individual information and collaborative information. Then, a multiobjective evolutionary algorithm is designed to solve this problem and a bidding selection problem for a major bridge project is used to demonstrate our proposed method. The results show that the decision-maker (DM) obtains a better contractor if he pays more attention to collaborative performance
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