A novel approach to subgraph selection with multiple weights on arcs

In this paper, an extension of the minimum cost flow problem is considered in which multiple incommensurate weights are associated with each arc. In the minimum cost flow problem, flow is sent over the arcs of a graph from source nodes to sink nodes. The goal is to select a subgraph with minimum associated costs for routing the flow. The problem is tractable when a single weight is given on each arc. However, in many real-world applications, several weights are needed to describe the features of arcs, including transit cost, arrival time, delay, profit, security, reliability, deterioration, and safety. In this case, finding an optimal solution becomes difficult. We propose a heuristic algorithm for this purpose. First, we compute the relative efficiency of the arcs by using data envelopment analysis techniques. We then determine a subgraph with efficient arcs using a linear programming model, where the objective function is based on the relative efficiency of the arcs. The flow obtained satisfies the arc capacity constraints and the integrality property. Our proposed algorithm has polynomial runtime and is evaluated in rigorous experiments.

     

Understanding the Role of Outsiders in Community-Based Development Interventions: A Framework with Findings from Iran

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This article analyzes various roles of development practitioners (called outsiders) in five different cases of...     

Iran and COVID-19: A Bottom-up,Faith-Driven,Citizen-Supported Response

Public Organization Review - The COVID-19 pandemic cast doubts on governments' traditional crisis responses and sparked a surge in citizen-led, participatory, bottom-up responses. Iran's...     

Analysis of incomplete durations with application to contraceptive use

Models for analysing incomplete durations obtained from cross-sectional surveys are presented. The aim of the paper is to develop a framework for analysing the incomplete duration of episodes in progress at the time of the survey by formulating generalized linear models and fitting and assessing them by using standard statistical packages. The maximum quasi-likelihood method is used for model fitting. The choice of the distribution and the diagnostic procedures are discussed. Simulated data from two distributions (the Weibull and log-logistic distributions) are used to evaluate the methodology developed and to assess model misspecifications. A data set on the current use of the contraceptive pill from a cross-sectional survey in Egypt is analysed.     

A Combined Nonlinear Programming Model and Kibria Method for Choosing Ridge Parameter Regression

Ridge regression solves multicollinearity problems by introducing a biasing parameter that is called ridge parameter; it shrinks the estimates as well as their standard errors in order to reach acceptable results. Many methods are available for estimating a ridge parameter. This article has considered some of these methods and also proposed a combined nonlinear programming model and Kibria method. A simulation study has been made to evaluate the performance of the proposed estimators based on the minimum mean squared error criterion. The simulation study indicates that under certain conditions the proposed estimators outperform the least squares (LS) estimators and other popular existing estimators. Moreover, the new proposed model is applied on dataset that suffers also from the presence of heteroscedastic errors.     

Bayesian Prediction for Progressively Type-II Censored Data from the Rayleigh Model

ABSTRACT

The Rayleigh distribution is proposed to be the underlying model from which observables are to be predicted by using Bayesian approach. Progressively Type-II censored data from the Rayleigh distribution is considered and the two-sample prediction technique is used. Numerical computations and a simulation are given to illustrate the performance of the procedures.     

A Study of the Relationship Between Innovation and Performance Among NPOs in Pakistan

Abstract

Innovation has become a core driver for the success and survival of organizations regardless of their size and nature. A plethora of literature has discussed the importance of innovation in profit-based organizations, while nonprofit organizations (NPOs) have generally been ignored in research. This study examines the influence of the sub-dimensions of innovation on the performance of NPOs. Data were collected through structured questionnaires using a sample size of 309 NPOs operating in the emerging market Pakistan. The hypotheses were tested through structural equation modeling (SEM) in AMOS.21. The results indicate that process innovation and organization innovation have significant positive influence on the performance of NPOs, while product innovation and marketing innovation have insignificant influence on the performance of NPOs. NPOs are advised to give enough attention to process and organization innovation in order to boost their performance. Future researchers are encouraged to test the model in other environmental settings. Implications for practice were discussed.     

Qualitative data analysis with hypertext: A case of New York City crack dealers

Ethnography has become a useful method in procuring sensitive information from the ‘hidden population’ who may not be accessed with quantitative survey techniques. Researchers are generating huge amounts of qualitative/textual data. Qualitative data require careful planning in storage, coding, retrieval, and analysis. Personal computers have solved data management problems, but data analysis remains problematic. The paper describes some qualitative data management and analytic problems faced by a team of ethnographers engaged in a longitudinal epidemiological study of cocaine and crack distribution/abuse in New York City. Ethnographic data was collected through multi-session open-ended interviews with more than one hundred cocaine/crack dealers and extensive field-notes were kept. Compared to other programs, a hypertext software — Folio Views — was more useful in solving (a) data management and (b) analytical problems. Authors used this software to handle more than twenty-five thousand pages of texts; search and sort the database by any words or codes; and retrieve relevant textual materials needed to complete comparative and thematic analysis. Authors analyzed the data from outsiders’ point of view (etic) as well as from the viewpoint of the subject populations (emic).     

The Effect of Board of Directors’ IT Awareness on CIO Compensation and Firm Performance

Chief information officers (CIOs) play increasingly strategic roles in firms in this competitive global economy, which is now largely powered by information technology (IT). However, research has shown a lack of board of directors’ oversight on CIO‐ and IT‐related issues. Drawing on agency, resource dependence, and alignment theories, we investigate the effect of board of directors’ IT awareness on CIO compensation structure and firm performance. We conduct cross‐sectional time series analyses of data collected from various sources. Our study underlines three important findings. First, we show that some commonly known executive compensation determinants, such as individual characteristics and governance structure, do not have significant effects on CIO compensation structure. Second, with regard to CIO compensation structure, firms respond to increasing information asymmetry differently according to the level of IT awareness of their boards. Finally, firms perform better when their boards have higher levels of IT awareness, and this positive effect of IT awareness is considerably larger in IT intensive industries. Overall, our study provides empirical support for the important role of boards’ IT awareness in shaping CIO compensation and improving firm performance. Our results suggest that boards with functional area knowledge—or higher IT awareness in this case—can more effectively monitor and better incentivize executives, and consequently lead to better firm performance.