A discrete particle swarm optimization for lot-streaming flowshop scheduling problem

We consider an n-job, m-machine lot-streaming problem in a flowshop with equal-size sublots where the objective is to minimize the total weighted earliness and tardiness. To solve this problem, we first propose a so-called net benefit of movement (NBM) algorithm, which is much more efficient than the existing linear programming model for obtaining the optimal starting and completion times of sublots for a given job sequence. A new discrete particle swarm optimization (DPSO) algorithm incorporating the NBM algorithm is then developed to search for the best sequence. The new DPSO improves the existing DPSO by introducing an inheritance scheme, inspired by a genetic algorithm, into particles construction. To verify the proposed DPSO algorithm, comparisons with the existing DPSO algorithm and a hybrid genetic algorithm (HGA) are made. Computational results show that the proposed DPSO algorithm with a two-point inheritance scheme is very competitive for the lot-streaming flowshop scheduling problem.     

Set Intersection Theorems and Existence of Optimal Solutions

The question of nonemptiness of the intersection of a nested sequence of closed sets is fundamental in a number of important optimization topics, including the existence of optimal solutions, the validity of the minimax inequality in zero sum games, and the absence of a duality gap in constrained optimization. We consider asymptotic directions of a sequence of closed sets, and introduce associated notions of retractive, horizon, and critical directions, based on which we provide new conditions that guarantee the nonemptiness of the corresponding intersection. We show how these conditions can be used to obtain simple and unified proofs of some known results on existence of optimal solutions, and to derive some new results, including a new extension of the Frank–Wolfe Theorem for (nonconvex) quadratic programming.     

Carbon-containing nano-titania prepared by chemical vapor deposition and its visible-light-responsive photocatalytic activity

Ultraviolet and visible-light-responsive titania was synthesized and employed in the NO_x photomineralization. A thermal decomposition reaction of titanium isopropoxide was carried out with a metal-organic chemical vapor deposition (MOCVD), enabling continuous production of TiO₂ nanoparticles. Carbon-containing titanium dioxide with the anatase phase prepared at 500 °C under nitrogen atmosphere exhibited high photocatalytic activity for NO oxidation under visible-light illumination. Experimental results indicate that up to 48% removal of NO_x can be achieved in a continuous flow type of reaction system under visible-light illumination (green LED). The chamber temperature in this MOCVD process plays an important role in lattice structure formation, and also affected TiO₂ carbon content. The carbonaceous species on the TiO₂ surface, shown by X-ray diffractometry (XRD), and Raman, UV–vis, and X-ray photoelectron spectroscopies (XPS), is important to the visible-light absorption and visible-light-catalytic mineralization of NO_x.     

Flexible facility interior layout: a real options approach

This paper explores a case of flexible facility layout, in which the layout process can be carried out in a dynamic manner responding to changing demands. We consider a facility such as an office building that needs to partition its interior space into units of different sizes and allocate them to different users. Facing different demands, each of which requires a different space size, the management of the facility needs to constantly exercise managerial real options, such as partitioning a big unit to small units and merging small units to a big one. Modelling the demand uncertainties as stochastic processes, we use the Monte Carlo simulation and solve rolling two-stage stochastic programs over time to value the flexible interior layout. Through numerical tests, we demonstrate that effectively and timely exercising the managerial options can significantly increase profit and service quality. Focusing on the dynamic behaviour of the facility interior layout, the proposed options-based approach aims to improve facility management by proactive decision strategies. The approach may also be extended to facility expansion, maintenance and rehabilitation to increase service life and maintain service quality.     

Power-equalized parallel-type pump-shared fiber lasers based on parameter-adjustment

A parallel-type, pump-shared (PTPS) scheme linear-cavity laser array (LCLA) is proposed and numerically studied. Power-equalization of multiwavelength fiber lasers can be achieved by varying the pumping power ratio, length of the erbium-doped fiber or reflectivity of grating reflector for the individual channels. Before and after power-equalization, the maximum power variation among seven equal-spaced channels, ranging from 1530 to 1560 nm, is 5.8 and 0.2 dB, respectively.     

Integrated CMOS system and thermally actuated optical switch for wavelength modulation/lock in communication network

The advancement of communication technology and growth of internet traffic have continuously driven the fast evolution of networks. Compared to the traditional optoelectronic switch, all-optical switch provides high throughput, rich routing functionalities, and excellent flexibility for rapid signal exchange in fiber optical network. Among various all-optical switches, thermal actuated ring switch provides the advantages of high accuracy, easy actuation, and reasonable switching speed. However, when scale up, thermal ring switch may encounter issues related to fabrication error, non-accurate wavelength response, and large terminal numbers in the control circuit. In this research, we propose the employment of an integrated CMOS control circuit to compensate the fabrication error and tune as well as lock the wavelength in a thermal-actuated ring-type optical switch through a frequency modulation scheme. Additional functionalities can also be added in this circuit by tailoring externally the roundtrip loss or coupling constants of the ring. The design concept can be easily scaled up for large array optical switch system without much change in the terminal numbers thanks to the three-dimensional hierarchy of control circuit design, which effectively reduces the terminal numbers into the cubic root of the total control unit numbers. The integrated circuit has been designed, simulated, as well as fabricated, and demonstrated a decent performance with free spectral range (FSR) equal to 1.5 nm at 1534 nm and very accurate wavelength modulation to 0.3 nm within 0.01 nm fluctuation for thermal actuated ring type optical switch.     

Enhancement of Anticancer Potential of Pterostilbene Derivative by Chalcone Hybridization

Pterostilbene, a natural metabolite of resveratrol, has been indicated as a potent anticancer molecule. Recently, several pterostilbene derivatives have been reported to exhibit better anticancer activities than that of the parent pterostilbene molecule. In the present study, a series of pterostilbene derivatives were designed and synthesized by the hybridization of pterostilbene, chalcone, and cinnamic acid. The cytotoxic effect of these hybrid molecules was determined using two oral cancer cell lines, HSC-3 and OECM-1. (E)-3-(2-((E)-4-Hydroxystyryl)-4,6-dimethoxyphenyl)-1-(2-methoxyphenyl)prop-2-en-1-one (4d), with IC₅₀ of 16.38 and 18.06 μM against OECM-1 and HSC-3, respectively, was selected for further anticancer mechanism studies. Results indicated that compound 4d effectively inhibited cell proliferation and induced G2/M cell cycle arrest via modulating p21, cyclin B1, and cyclin A2. Compound 4d ultimately induced cell apoptosis by reducing the expression of Bcl-2 and surviving. In addition, cleavage of PARP and caspase-3 were enhanced following the treatment of compound 4d with increased dose. To conclude, a number of pterostilbene derivatives were discovered to possess potent anticancer potentials. Among them, compound 4d was the most active, more active than the parent pterostilbene.     

双相不锈钢在水溶液中之腐蚀疲劳与动态应变时效

本研究主要探讨 2 2 %Cr双相不锈钢在含氯离子水溶液中之腐蚀疲劳裂缝成长行为 ,以及在慢应变速率拉伸试验过程中所发生的动态应变时效现象 .同时以 31 6L沃斯田体系不锈钢及4 30肥粒体系不锈钢作为比较 ,藉以探讨不同晶体结构对腐蚀疲劳及动态应变时效行为的影响 .实验结果显示 ,在 80℃ ,3.5wt%NaCl水溶液中 ,3种不锈钢并未发生应力腐蚀破裂 ,但其中 31 6L沃斯田体系不锈钢及 2 2 %Cr双相不锈钢却发生动态应变时效 ,且动态应变时效的发生与温度 ,应变速率及沃斯田体相的组织有关 .在NaCl水溶液中 ,采用预裂试片量测疲劳裂缝生长速率 ,其结果表明 ,4 30肥粒体系不锈钢之疲劳裂缝生长速率最快 ,而氢脆是加快裂缝生长速率的主因 ,就双相不锈钢而言 ,腐蚀疲劳裂缝的生长主要与该不锈钢所含之肥粒体相的氢脆现象有关