The authors present a thermal unit commitment method for interconnected multiarea power systems. is natural extension of the utilization factor (CUF)-based single-area method. CUF extended to reflect impact transmission interconnection constraints on efficiency committing candidate at given priority position. used in conjunction with average full load cost. (AFLC) efficiently determine optimal or near-optimal order. This order then generate schedule. excellent quality results CUF-based...

Summary  This paper proposes a test for the null of sphericity in fixed effects panel data model. It uses the Random Matrix Theory based approach Ledoit and Wolf to error terms model with large number cross-sectional units time series observations. Because errors are unobservable, residuals from regression used. The limiting distribution proposed statistic is derived. In addition, its finite sample properties examined using Monte Carlo simulations.

A combined control variable and stratified sampling method is proposed for Monte Carlo production simulation. Using the cost obtained from load duration curve type simulation as variable, both theory a sample study suggest that required (for an acceptable coefficient of variation) number samples can be reduced by approximately factor 1000. In example study, 8000 were replaced with 10 samples; in addition, using produces estimator mean has much smaller variance than based on traditional which...

Summary This paper extends Pesaran's ( Econometrica , 2006, 74 967–1012) common correlated effects (CCE) by allowing for endogenous regressors in large heterogeneous panels with unknown structural changes slopes and error factor structure. Since breaks are often encountered empirical studies panels, this extension makes CCE approach empirically more appealing. In addition to slope heterogeneity cross‐sectional dependence, we find that is also valid when dealing unobservable factors the...

Overseas listings by domestic firms are one of the ways for a country to attract foreign capital. China leads world in number and value overseas listings. This paper documents evolution Chinese firms’ initial public offerings outside mainland China. We pay special attention role listing criteria various exchanges this evolution. discuss important reforms requirements both Hong Kong their effects on location choices firms. Finally, we examine delisting pressure stocks from US authorities.

SUMMARY In the fixed‐effects stochastic frontier model an efficiency measure relative to best firm in sample is universally employed. This paper considers a new worst sample. We find that estimates of this have smaller bias than those traditional when consists many firms near efficient frontier. Moreover, two‐sided both and proposed. Simulations suggest measures may be preferred depending on skewness inefficiency distribution scale differences. Copyright © 2010 John Wiley & Sons, Ltd.

The feasibility of composite-activated coal gangue (CACG) as the primary cementitious material for concrete was experimentally studied in this paper. effects strength grade on slump and flow, compressive strength, splitting tensile axial elastic modulus, drying shrinkage alkali-activated (AACGC) were investigated. Experimental results indicated that flow AACGC smaller than ordinary Portland cement (OPCC). mechanical properties superior to those OPCC. modulus 1.17 times, 1.04 1.47 times OPCC,...

Under action of repeated freeze-thaw cycles, different changes pore structure features has occurred in varieties concrete.In this study, the average size concrete and total porosity was discussed especially with trends.Based on this, gas diffusion model chloride ion also structure,which indicated that damage will have a greater impact to durability concrete, so life structures would be affected.

The experiment aimed to obtain a quadratic regression mathematical model of the comprehensive evaluation score yield, quality, and four macroelements (N, K, P Ca). suitable nutrient solution was chosen verified via computer simulation highest in all treatments. Results showed that P, K Ca had positive effect on value tomato, whereas N negative effect. optimal formula calculated using equation could promote high-yield high-quality tomato. single-plant soluble protein, vitamin C, total sugar,...

Porous poly- D, L-lactic acid (PDLLA) electrospinning fiber membrane was prepared, and nano-hydroxyapatite (nHA) adsorbed wrapped into it during the unique shrinking process of PDLLA to fabricate PDLLA/nHA composite scaffold for tissue engineering. Compare with fibers prepared by blend electrospinning, most nHA particles are observed distribute on surface new type fibers, which could significantly improve water wettability induce cellular adherence. FTIR analysis indicated that fibrous...

While coping with nonsphericality of the disturbances, standard GMM suffers from a blind spot for exploiting most effective instruments when these are obtained directly unconditional rather than conditional moment assumptions. For instance, counteracts that exogenous regressors used as their own optimal instruments. This is easily seen after transmuting linear models into IV in terms transformed variables. It demonstrated modified (MGMM), straight-forward modifications instruments, can...

The effects of the wet-dry cycles on chemical compositions, microstructure, and mechanical properties Pisha sandstone were experimentally investigated in current study. A series uniaxial compression tests conducted to validate deterioration property specimens after cycles. In addition, evolutions mineral compositions microstructure characteristics confirmed by X-ray diffraction (XRD) scanning electron microscope (SEM). Experimental results indicated that with increase cycles, gradually...