Sensitivity analysis for simulation-based decision making: Application to a hospital emergency service design

An increasing concern of decision makers when dealing with system design is preparation for a wide range of potentially uncertain operating conditions. This paper provides a novel multiobjective approach for simulation-driven decision making that accounts for not only the conventional average system performance indices, but also (i) upper-tail, or extreme, values of these indices, and (ii) measures of their sensitivity to uncertainty in model parameters. The proposed approach is applied to a hospital emergency department service design case study wherein different design alternatives are compared using total time-in-system performance metric under multiple uncertain operating conditions.     

Antecedents of stressful experiences: Depressive symptoms, self-esteem, gender, and coping.

Numerous studies have identified depressive symptoms as antecedent to stressful experiences. However, the interrelations of depressive symptoms, personal resources, and coping as antecedents of stressful experiences are largely unknown. For this investigation, a prospective design was used to test a model estimating two categories of daily hassles at Time 2 in relation to depressive symptoms, self-esteem, gender, coping, and daily hassles at Time 1. Utilizing simultaneous equations, direct effects were observed for depressive symptoms, Time 1 hassles, gender, and avoidance coping in relation to category of hassles at Time 2. Depressive symptoms and avoidance coping were observed to be mediators for gender and self-esteem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morphology of peripheral airways in current smokers and ex-smokers

To investigate the effect of smoking status on pulmonary function and pathologic changes in the peripheral airways, we studied 97 patients who underwent thoracotomy for coin lesions. The patients were divided into 4 groups: nonsmokers (n = 9), current smokers (n = 51), and those who had ceased smoking for less than (n = 18) or more than (n = 19) 2 yr prior to surgery. We found that current smokers had evidence of air-flow obstruction with abnormal lung volumes when compared with nonsmokers. Ex-smokers had lung volumes similar to those of nonsmokers, but showed evidence of obstruction, with the FEV1/FVC between the values found for nonsmokers and current smokers. Examination of the small airways showed that the membranous bronchioles of current smokers and ex-smokers displayed only increased goblet cell metaplasia when compared with those in nonsmokers; the respiratory bronchioles of current and ex-smokers showed increases in intraluminal and airway wall inflammatory cells, wall fibrosis, and pigment deposition. We conclude that patients who currently smoke cigarettes have reduced lung function that is associated with abnormalities of airway structure. Although those who have stopped smoking have function that is closer to the nonsmoking group, there is no apparent difference in structural change between current and ex-smokers.     

Cardiovascular and biochemical evidence of stress during major surgery associated with different techniques of anaesthesia

The relative merits of a potent narcotic and a spinal analgesic to affect the stress response to a standard operation have been assessed. Forty-five fit patients scheduled for abdominal hysterectomy were allocated at random to three groups, referred to as standard (i.v. anaesthesia alone), spinal (spinal plus i.v. anaesthesia) and fentanyl (fentanyl plus i.v. anaesthesia) groups. In the doses used, fentanyl produced the most effective attenuation of the cardiovascular, hormonal and metabolic responses to stress, but had the disadvantage of prolonged respiratory depression. Spinal anaesthesia gave only a modified blockade of the response to stress and did not obtund the response to intubation.     

SEMPA – Ein Ansatz des Semantischen Prozessmanagements zur Planung von Prozessmodellen

Currently process modeling is mostly done manually. Therefore, the initial design of process models as well as changes to process models which are frequently necessary to react to new market developments or new regulations are time-consuming tasks. In this paper we introduce SEMPA, an approach for the partly automatic planning of process models. Using ontologies to semantically describe actions – as envisioned in Semantic Business Process Management –, a process model for a specified problem setting can be created automatically. In comparison to existing planning algorithms our approach creates process models including control structures and is able to cope with complex and numerical input and output parameters of actions. The prototypical implementation as well as an example taken from the financial services domain illustrate the practical benefit of our approach.     

Density and crystallinity of poly (3-hydroxybutyrate/3-hydroxyvalerate) copolymers

Bacteria can produce a range of optically active copolymers of (R)-3-hydroxybutyrate (HB) and (R)-3-hydroxyvalerate (HV). These copolymers have aroused much scientific interest because of their high crystallinity at all HB ∶ HV compositions which suggests the possibility of inclusion of HB and HV in the same crystal. In this paper we look at the assessment of crystallinity by density measurements taking into account the possible changes in crystal and amorphous densities caused by the rejection or inclusion of HV from the crystallites. The approach developed is applicable to crystallization of copolymers and blends whatever the composition of the crystals and makes a distinction between mass fraction and mole fraction crystallinities for cases where the average molar mass of residues in the crystal and amorphous phases differs. While it is impossible to give values for crystallinity without knowing the degree of inclusion of HV into the crystals it is possible to say that the previous suggestions that the crystallinity remains constant independent of HV content and that there is equal concentration of HV in the crystal and amorphous phases are incompatible with the measured sample densities. We also show that the crystallization temperature is an important factor in the balance between the crystallinity and HV content of crystals.     

Types as Graphs: Continuations in Type Logical Grammar

Using the programming-language concept of continuations, we propose a new, multimodal analysis of quantification in Type Logical Grammar. Our approach provides a geometric view of in-situ quantification in terms of graphs, and motivates the limited use of empty antecedents in derivations. Just as continuations are the tool of choice for reasoning about evaluation order and side effects in programming languages, our system provides a principled, type-logical way to model evaluation order and side effects in natural language. We illustrate with an improved account of quantificational binding, weak crossover, wh-questions, superiority, and polarity licensing.