Commissioning of CIL's ammonia II plant

Special features of this process design contributed to fast start-up, including the role of the computer simulator for training purposes and the concept of commissioning by process test system.     

Statistical Independence and Fractional Age Assumptions

Abstract

This paper considers in some detail the issue of statistical independence of the curtate future lifetime and the fractional part of the future lifetime of a general status.

Statistical independence is often employed in actuarial contexts, primarily because it leads to simple relationships between quantities of interest and statistical information that is of a discrete nature, such as a life table. The uniform distribution of deaths (UDD) assumption is the most commonly used because of its simplicity and intuitive appeal, but it can be somewhat restrictive. For example, all deaths or withdrawals may be assumed to be at a particular point in the year such as the middle; assumptions of this type are often made in a multiple decrement context. This paper attempts to unify these assumptions and extend their applicability in an actuarial context.

The conditions for independence need to be stated carefully, and the last-survivor status is cited as an example in which failure to do so can lead to erroneous conclusions.

The fractional independence (Fl) assumption is defined, and it is demonstrated that many of the formulas for life table functions that hold under the more restrictive UDD assumption are extended easily to the general Fl case. The simple relationship under UDD between insurances payable on other than an annual mode and those payable at the end of the year of death is extended to the Fl case as well. These results are then used to obtain results for annuities and reserves, again generalizing UDD relationships. It is then demonstrated that many contingent probabilities in the multiple life context are exactly the same under the Fl assumption as under the more restrictive UDD assumption. Finally, a very general result that holds in the multiple decrement context is shown to hold under the Fl assumption.     

Unit Root Testing under a Local Break in Trend using Partial Information on the Break Date*

We consider unit root testing allowing for a break in trend when partial information is available regarding the location of the break date. This takes the form of knowledge of a relatively narrow window of data within which the break takes place, should it occur at all. For such circumstances, we suggest employing a union of rejections strategy, which combines a unit root test that allows for a trend break somewhere within the window with a unit root test that makes no allowance for a trend break. Asymptotic and finite sample evidence shows that our suggested strategy works well, provided that, when a break does occur, the partial information is correct. An empirical application to UK interest rate data containing the 1973 ‘oil shock’ is also considered.     

Editorials and geopolitical explanations for 11 September

In the wake of the 11 September attacks, public intellectuals, editorialists and newspaper columnists began to attempt to offer largely geopolitical explanations for the attacks through editorials and op-ed pieces. In this essay we analyze some sixty editorials and op-ed pieces from a range of perspectives. We classify the editorials under five main categories of geopolitical explanation: imperialism, ‘blowback’, state decline, Islamism, and the ‘clash of civilizations’ perspectives. We then discuss each category of explanation, highlighting the arguments made, the theoretical perspectives which inform them, and counterarguments, when presented. In our conclusion we discuss the strengths and weaknesses of the categories and suggest that geographers might help provide some integration of these varying perspectives.     

Culture,Self-Construal,and Leisure Motivations

The purpose of this study is to examine Canadian and Mainland Chinese students' leisure by investigating the role self-construal plays as an intervening variable between culture and motivation. Separate hierarchical multiple regressions are performed on each motivation with culture entered first followed by a block composed of four types of self-construal: vertical collectivism (i.e., dutiful), horizontal collectivism (i.e., cooperative), horizontal individualism (i.e., unique), and vertical individualism (i.e., achievement oriented). Results suggest that: (a) higher levels of horizontal collectivism are associated with higher levels of introjected reward (i.e., pride), identified (i.e., personally important), integrated (self-identity), and intrinsic (i.e., interesting and enjoyable) motivations; and (b) higher levels of horizontal individualism are associated with higher levels of introjected reward, identified, and integrated motivations.     

Effects of Free Trade on Women and Immigrants: CAFTA and the Rural Dominican Republic

We construct a disaggregated rural economywide model with a focus on gender and immigration as well as on the allocation of time to wage work, household production activities, and housework (reproduction). We use this model to simulate the impacts of the Dominican Republic-Central American Free Trade Agreement (DR-CAFTA) on rural incomes and welfare in the Dominican Republic. We find that elimination of agricultural import tariffs hurts both agricultural and non-agricultural households, via adverse factor-market effects, but impacts vary substantially by workers’ gender and country of origin. Females and Haitian immigrants tend to fare better than Dominican males, and there are ramifications for both market and non-market activities.     

Adding a freight network to a national interstate input–output model: a TransNIEMO application for California

The state of the nation’s infrastructure is the subject of widespread discussion and comment because it is thought to include many deteriorating and unsafe bridges. Ever since the terrorist attacks of 9/11, there has been increasing concern over the extent to which an attack on infrastructure could result in serious economic disruption. This research develops a model to analyze the economic consequences of an attack on a major element of the highway network. We add a freight network to a national multiregional economic impact model and make freight traffic flows endogenous. The use of a sub-national interstate model recognizes that most infrastructure planning is at the state level and most political leaders’ interest is local. We base our approach on the National Interstate Economic Model (NIEMO) and refer to an elaboration that we name Transportation network and the National Interstate Economic Model (TransNIEMO). The new model enables us to study the state-specific and industry-specific economic impacts of some significant changes in the nature of highway freight movements. We tested the model for selected freight movements in and out of California. The results are entirely plausible and encourage us to elaborate and test the model for hypothetical disruptions of freight traffic throughout the US.