A Supply Chain Equilibrium Model with General Price-Dependent Demand

The concept of supply chain equilibrium has been widely employed to solve real-life cases. Under this concept, decisions makers move simultaneously and compete in a noncooperative manner to achieve a supply chain network equilibrium. This paper proposes a supply chain network equilibrium model consisting of multiple raw material suppliers, manufacturers and retailers. Unlike previous studies, we assume that the demand for the product at each retail outlet is modeled as general stochastic functions of price that encompass additive-multiplicative demand models used in previous studies. Under general price-dependent demand functions, we derive the optimality conditions of suppliers, manufacturers and retailers, and establish that the governing equilibrium conditions can be formulated as a finite-dimensional variational inequality problem. The existence and uniqueness of the solution to the variational inequality are examined. A sensitivity analysis and a series of numerical tests are conducted to illustrate the analytical effects of demand distribution, model parameters, demand level and variability on quantity shipments, prices, and expected profits. Managerial insights are reported to show the impact of different types of demand functions and model parameters on the equilibrium solutions

Estimation of bivariate excess probabilities for elliptical models

Let $(X,Y)$ be a random vector whose conditional excess probability $\theta(x,y):=P(Y\leq y | X>x)$ is of interest. Estimating this kind of probability is a delicate problem as soon as $x$ tends to be large, since the conditioning event becomes an extreme set. Assume that $(X,Y)$ is elliptically distributed, with a rapidly varying radial component. In this paper, three statistical procedures are proposed to estimate $\theta(x,y)$ for fixed $x,y$, with $x$ large. They respectively make use of an approximation result of Abdous et al. (cf. Canad. J. Statist. 33 (2005) 317--334, Theorem 1), a new second order refinement of Abdous et al.'s Theorem 1, and a non-approximating method. The estimation of the conditional quantile function $\theta(x,\cdot)^{\leftarrow}$ for large fixed $x$ is also addressed and these methods are compared via simulations. An illustration in the financial context is also given.Comment: Published in at http://dx.doi.org/10.3150/08-BEJ140 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Dual sourcing inventory management with nonconsecutive lead times from a supply chain perspective: a numerical study

We study a stochastic multi-period two-echelon dual sourcing inventory system where the buyer can source a product from two different suppliers: a regular and an expedited supplier. The regular supplier is a low-cost offshore supplier, whereas the expedited supplier is a responsive nearshore supplier. Such dual sourcing inventory systems have been well studied in the literature, mostly being solely evaluated from the buyer’s perspective. Since the buyer’s decisions have an impact on the supply chain profit, we adopt the perspective of the entire supply chain, i.e., by taking the suppliers explicitly into consideration. In addition, we study this system for general (nonconsecutive) lead times for which the optimal policy is unknown or very complex. We numerically compare the performance of two different policies in a two-echelon setting: the Dual-Index Policy (DIP) and the Tailored Base-Surge Policy (TBS). From earlier studies we know that when the lead time difference is one period, DIP is optimal from the buyer’s perspective, but not necessarily from the supply chain perspective. On the other hand, when the lead time difference grows to infinity, TBS becomes optimal for the buyer. In this paper, we evaluate the policies numerically (under various conditions) and we show that from a supply chain perspective, TBS typically outperforms DIP at a limited lead time difference of a few time periods. Based on data collected from 51 manufacturing firms, the results of our paper imply for many supply chains with a dual sourcing setting that TBS quickly becomes a beneficial policy alternative, especially given its simple and appealing structure

A Nonparametric Test of Serial Independence for Time Series and Residuals

AbstractThis paper presents nonparametric tests of independence that can be used to test the independence of p random variables, serial independence for time series, or residuals data. These tests are shown to generalize the classical portmanteau statistics. Applications to both time series and regression residuals are discussed

Smart plugs: Perceived usefulness and satisfaction: Evidence from United Arab Emirates

© 2015 The Authors. The UAE per capita energy consumption is one of the highest in the world. Since the energy sector is the center of most ecological problems facing the world today, eco-efficiency and eco-innovations are at the top of the sustainability agenda in most countries. The UAE "Green Economy for Sustainable Development" (2012-2021) aims to position the country as a center for the export and re-export of green products and technologies. In light of the above, the focus of this paper is to present a smart plug system for monitoring and controlling household energy consumption using a mobile application. The smart plug system is an essential component in smart grids as it provides real-time high-resolution information for distribution companies to aid them in decision-making. In addition, the study measures the perceived usefulness and satisfaction of the smart plug system and its mobile application in the UAE. The paper makes an important theoretical contribution by including environmental concern as an additional variable to a well-established information systems success model. Our findings suggest that the smart plug system provides users with convenient access to information regarding their personal energy consumption and allows them to control their per capital energy consumptions via the mobile application at very low costs. Further, we validated our theoretical model using structural equation modeling and conclude that environmental concern has an indirect impact on the perceived satisfaction and both an indirect and a direct impact on the perceived usefulness of the smart plug system. The practical implications of our study suggest that per capita energy consumption is likely to significantly decrease with wide adoption of the smart plug system in the UAE

Empirical Processes Based on Pseudo-Observations

. Usually, empirical distribution functions are used to estimate the theoretical distribution function of known functions `(X) of the observable random variable X. In practice, many researchers are using empirical distribution functions constructed from residuals, which are estimations of a non-observable error terms in linear models. This falls under a class of more general problems in which one is interested in the estimation of the distribution function of a non-observable random variable `(Q; X) depending on an observable random variable X together with its unknown law Q. When Q is estimated by some Qn , the quantities `(Qn ; X i ) are called pseudo-observations. Some work has been done recently when the pseudo-observations are the so-called residuals of linear models. The aim of this paper is to provide some tools to study the asymptotic behavior of empirical processes constructed from general pseudo-observations. Examples of pseudoobservations will be given together with applica..

Assessing the Emotional Affordance of Brand Image and Foreign Image Based on a Physiological Method Using Examples from Dubai: Exploratory Study

The United Arab Emirates (UAE) is a country with few restrictions on architectural styles. The main aim of this paper was to investigate a group of participants’ unconscious emotional responses to images of traditional and modern architectural styles in the UAE. All images were from the city of Dubai, but participants were from elsewhere to avoid the influence of familiarity. A physiological method was used to measure the unconscious emotional responses to the images’ visual contexts, specifically the emotions of stress, engagement, interest, focus, excitement, and relaxation. Six architects working in the UAE were then interviewed for their interpretations of both the images themselves and the participants’ emotional responses. A sample of 29 male laypeople (aged 18–45) participated in this study, divided into locals from Al Ain city, locals from the northern emirates, and nonlocals. The results showed that the brand image provided observers with better emotional quality than the foreign image for local participants from Al Ain, and that nonlocal participants showed strong emotional responses to the traditional architecture, but the northern Emiratis remained neutral. The findings of this study contribute to emotion studies in the field of meaning in architecture. It also validates the effectiveness of a physiological method of investigating the emotional responses to architectural styles

Assessing the Emotional Affordance of Brand Image and Foreign Image Based on a Physiological Method Using Examples from Dubai: Exploratory Study

The United Arab Emirates (UAE) is a country with few restrictions on architectural styles. The main aim of this paper was to investigate a group of participants’ unconscious emotional responses to images of traditional and modern architectural styles in the UAE. All images were from the city of Dubai, but participants were from elsewhere to avoid the influence of familiarity. A physiological method was used to measure the unconscious emotional responses to the images’ visual contexts, specifically the emotions of stress, engagement, interest, focus, excitement, and relaxation. Six architects working in the UAE were then interviewed for their interpretations of both the images themselves and the participants’ emotional responses. A sample of 29 male laypeople (aged 18–45) participated in this study, divided into locals from Al Ain city, locals from the northern emirates, and nonlocals. The results showed that the brand image provided observers with better emotional quality than the foreign image for local participants from Al Ain, and that nonlocal participants showed strong emotional responses to the traditional architecture, but the northern Emiratis remained neutral. The findings of this study contribute to emotion studies in the field of meaning in architecture. It also validates the effectiveness of a physiological method of investigating the emotional responses to architectural styles