Product variety is an important component of consumer welfare, yet many markets have historically been dominated by a small number of best-selling products. The Pareto Principle, also known as the 80/20 rule, describes this common pattern of sales concentration. However, by greatly lowering search costs, information technology in general and Internet markets in particular have the potential to ...

Many markets have historically been dominated by a small number of best-selling products. The Pareto Principle, also known as the 80/20 rule, describes this common pattern of sales concentration. However, information technology in general and Internet markets in particular have the potential to substantially increase the collective share of niche products, thereby creating a longer tail in the ...

background: reusing orthodontic mini-screws would reduce treatment cost and lead to more use of mini-screws and improvement of orthodontic treatments. this study has assessed the effects of reprocessing and reusing the titanium mini-screws on their maximum insertion, removal and fracture torque (ft). materials and methods: in this experimental study, 20 titanium mini-screws (1.6-mm × 8-mm) were...

BACKGROUND In order to understand the cross-resistance between epirubicin (EPI) and mitoxantrone (MIT), EPI- and MIT-resistant cells were established and their cross-resistance was evaluated. MATERIALS AND METHODS The degrees of growth inhibition of EPI-resistant HLE-EPI cells and MIT-resistant HLE-MIT cells by anticancer drugs were measured. The mRNA expressions of multidrug resistance prote...

es wird gezeigt, dass bei der standiger zunahme der production von roheisen ,die fast ausschliesslich in hochofen erfolgt, der gestelldurchmesser und die ofeneinheit zunimmt demgegenuber der spezifische brennstoffverbrauch abnimmt. weiterhin wird die entwicklungsrichtung der stahlerzeungsverfanren wegen der wirtschaftlichen und technischen hinsicht untersucht und festgestellt, dass nuter versch...

The mechanism for regulating the critical temperature (TC) of metal-insulator transition (MIT) in ions-doped VO2 systems is still a matter of debate, in particular, the unclear roles of lattice distortion and charge doping effects. To rule out the charge doping effect on the regulation of TC, we investigated Ti(4+)-doped VO2 (Ti(x)V(1-x)O2) system. It was observed that the TC of Ti(x)V(1-x)O2 s...

Fuzzy Newton-Cotes method for integration of fuzzy functions that was proposed by Ahmady in [1]. In this paper we construct error estimate of fuzzy Newton-Cotes method such as fuzzy Trapezoidal rule and fuzzy Simpson rule by using Taylor's series. The corresponding error terms are proven by two theorems. We prove that the fuzzy Trapezoidal rule is accurate for fuzzy polynomial of degree one and...

My paper has two parts. First, I talk about the golden rule. After introducing the rule and its global importance, I explain why many scholars dismiss it as a vague proverb that leads to absurdities when we try to formulate it clearly. I defend the golden rule against such objections. Second, I talk about the golden rule in Persia and Islam; I consider Persian sources (Muslim and non-Muslim) an...

This paper develops a model with endogenously coarse rules. A principal hires an agent to take an action. The principal knows the optimal state-contingent action, but cannot communicate it perfectly due to communication constraints. The principal can use previously realized states as examples to define rules of varying breadth. We analyze how rules are chosen under several assumptions about how...