Program Evaluation and Review Technique (PERT) in Construction Schedule Risk Assessment

Construction project scheduling is one of the most critical factors for project success measurement.Not only for the project planning but for construction process management,the scheduling is the basic tool for communication between the owner and the project manager.By developing the schedule before the project starts,the owner knows in advance that the expected timeline of the project.By preparing construction process scheduling,the owner and general contractor can better manage the subcontractors,sub-trades progress,materials storage and deliveries,labors schedule and equipment set up which will eventually save time,money and hassle.Basically,Critical Path Method(CPM) is commonly used in the construction industry.CPM is a deterministic method that assumes that through the network,there is at least one path that determines the project duration and that the path is the critical path.CPM does not consider the uncertainty in the activities;rather it assumes that each activity can be finished in the given situation.Program Evaluation and Review Technique(PERT) is a stochastic technique which is based on the assumption that the duration of a single activity can be described by a probability density function.PERT takes into account the uncertainty during the construction process and has been created out of the need to plan,schedule and control complex projects with many uncertainties.The PERT approach is stated in some books and papers,but there is no deep investigation on the application in the schedule risk assessment.This paper investigates the PERT work process and takes a valuable try on the construction schedule risk assessment by using case studies.The utilization in the estimate the construction liquidated damage with the uncertainties is performed,which also can be used in the insurance company to calculate the insurance premium.     

Did Leaving the Gold Standard Tame the Business Cycle? Evidence from NBER Reference Dates and Real GNP

Cover and Pecorino (2005) claim that the March 1933 departure from the gold standard is the most probable break point ushering in an era of longer U.S. expansions, both absolutely and relative to subsequent recessions. Their analysis is based on cycle durations as defined by National Bureau of Economic Research (NBER) reference dates. However, much of macroeconomic analysis is based on (i) growth cycles (i.e., periods when the economy's production is above or below trend) rather than absolute increases or decreases in economic activity; and (ii) aggregate time series' volatility as the prime indicator of macroeconomic stability. In light of this, we reevaluate the March 1933 break point. First, using HP‐filtered quarterly gross national product (GNP), our analysis of growth cycle durations still implies a break point near 1933. Second, we test for structural breaks in the volatility of GNP growth rates and deviations from trends. These tests suggest a structural break considerably later than 1933, perhaps as late as the 1950s.     

ROBUST ASSET ALLOCATION WITH BENCHMARKED OBJECTIVES

In this paper, we introduce a new approach for finding robust portfolios when there is model uncertainty. It differs from the usual worst‐case approach in that a (dynamic) portfolio is evaluated not only by its performance when there is an adversarial opponent (“nature”), but also by its performance relative to a stochastic benchmark. The benchmark corresponds to the wealth of a fictitious benchmark investor who invests optimally given knowledge of the model chosen by nature, so in this regard, our objective has the flavor of min–max regret. This relative performance approach has several important properties: (i) optimal portfolios seek to perform well over the entire range of models and not just the worst case, and hence are less pessimistic than those obtained from the usual worst‐case approach; (ii) the dynamic problem reduces to a convex static optimization problem under reasonable choices of the benchmark portfolio for important classes of models including ambiguous jump‐diffusions; and (iii) this static problem is dual to a Bayesian version of a single period asset allocation problem where the prior on the unknown parameters (for the dual problem) correspond to the Lagrange multipliers in this duality relationship. This dual static problem can be interpreted as a less pessimistic alternative to the single period worst‐case Markowitz problem. More generally, this duality suggests that learning and robustness are closely related when benchmarked objectives are used.     

Cross-country differences in attitudes to business associations during the 2007–2010 recession

This paper uses empirical data gathered through an on-line survey of 206 small and medium-sized enterprises (SMEs), conducted in France, Sweden and the UK. The paper examines cross-country differences in SME managers’ perceptions of business associations as sources of political intelligence and their ability to influence policy responses to financial crises. Findings demonstrate that the respondents’ countries of origin are significantly correlated with (1) their use of information sources to gather political intelligence, (2) their perceptions regarding the effectiveness of business associations in influencing policy outcomes, and (3) their perceptions regarding policymakers’ appreciation of information provided by SME associations.     

How Does Brand-related User-generated Content Differ across YouTube,Facebook, and Twitter?

This study tests hypotheses regarding differences in brand-related user-generated content (UGC) between Twitter (a microblogging site), Facebook (a social network) and YouTube (a content community). It tests them using data from a content analysis of 600 UGC posts for two retail-apparel brands (Lululemon and American Apparel), which differ in the extent to which they manage social media proactively. Comparisons are drawn across six dimensions of UGC; the dimensions were drawn from a priori reading and an inductive analysis of brand-related UGC. This research provides a general framework for comparing brand-related UGC, and helps us to better understand how particular social media channels and marketing strategies may influence consumer-produced brand communications.     

Opportunities to reduce road traffic injury: new insights from the study of urban areas

Abstract

Over the past four decades considerable efforts have been taken to mitigate the growing burden of road injury. With increasing urbanisation along with global mobility that demands not only safe but equitable, efficient and clean (reduced carbon footprint) transport, the responses to dealing with the burgeoning road traffic injury in low- and middle-income countries has become increasingly complex. In this paper, we apply unique methods to identify important strategies that could be implemented to reduce road traffic injury in the Asia-Pacific region; a region comprising large middle-income countries (China and India) that are currently in the throes of rapid motorisation. Using a convolutional neural network approach, we clustered countries containing a total of 1632 cities from around the world into groups based on urban characteristics related to road and public transport infrastructure. We then analysed 20 countries (containing 689 cities) from the Asia-Pacific region and assessed the global burden of disease attributed to road traffic injury and these various urban characteristics. This study demonstrates the utility of employing image recognition methods to discover new insights that afford urban and transport planning opportunities to mitigate road traffic injury at a regional and global scale.     

Richard Abel. Americanizing the Movies and "Movie-Mad" Audiences, 1910-1914

Richard Abel argues that in the period from 1910, when the motionpicture "revolution" succeeded and the American film marketwas emancipated from French domination, to 1914, when foreignfilms were nearly eliminated from the U.S. market, the Americanfilm industry was characterized by widespread experimentationand innovation, especially in the areas of promotion practices,distribution strategies, content refinement, and audience development.Six chapters of Abel's Americanizing the Movies bring to theforeground the battle of