Weak imposition of Signorini boundary conditions on the boundary element method

We derive and analyse a boundary element formulation for boundary conditions involving inequalities. In particular, we focus on Signorini contact conditions. The Calder\'on projector is used for the system matrix and boundary conditions are weakly imposed using a particular variational boundary operator designed using techniques from augmented Lagrangian methods. We present a complete numerical a priori error analysis and present some numerical examples to illustrate the theory

Performance in Consumer Financial Services Organizations: Framework and Results from the Pilot Study

Financial services comprise over 4 percent of the gross domestic product of the United States and employ over 5.4 million people. By offering vehicles for investment of savings, extension of credit and risk management, they fuel the modern capitalistic society. While the essential functions performed by the organizations that make up the financial services industry have remained relatively constant over the past several decades, the structure of the industry has undergone dramatic change. Liberalized domestic regulation, intensified international competition, rapid innovations in new financial instruments and the explosive growth in information technology fuel this change. With this change has come increasing pressure on managers and workers to dramatically improve productivity and financial performance. This paper summarizes the first year of a multi-year effort to understand the drivers of performance in financial services organizations. Financial services are the largest single consumer of information technology in the economy, investing $38.7 billion dollars in 1991 (National Research Council, 1994). While this investment has had a profound effect on the structure of the industry and the products it provides, its effect on financial performance of the industry remains elusive. Why this "productivity paradox" (Brynjolfsson and Hitt,1993) exists is an important part of this project. The authors describe the differences in productivity in services from manufacturing. In the service world, the consumer co-produces the product with the firm, ofte nadding labor to the creation of the service. In addition, the scope of the service enterprise typically is quite vast, with components of the service production process being both producers and deliverers of the service. In addition, the quality of the services provided is forever changing. Thus, the authors suggest that productivity gains from human resource improvements or technology investments may not show up in standard performance measures, but may rather be used to improve the quality of the service provided. What appears to be a stagnation in productivity may actually be an increase in value delivered to the customer. Delivering value to the customer may provide the institution with sales opportunities and much needed information about the institution's customer base. The pilot survey conducted by the authors examines the relationship between technological advancement and the relational part of service delivery by studying time spent with the customer in relation to technological sophistication and time spent on the entire delivery process. The authors adopt the view that processes are the central "technology" of an organization. As with any technology, the process must be maintained. After a process has reached its useful life, it should be scrapped or rebuilt. Thus, the authors suggest that researchers should take a life-cycle view of processes when undertaking efficiency studies. The authors rely heavily on a process-oriented methodology in their analysis of performance drivers in financial services. The study does not focus on traditional measures of productivity or financial performance. Rather, the authors base comparisons on intermediary measures which evaluate the drivers of performance from the perspective of all participants in the co-productive process. This pilot study starts with consumer financial services and in particular, retail banking. The authors review the relevant literature on financial services performance and then propose a conceptual framework for the study. The framework assumes that industry conditions and firm strategy are given. The authors focus is to examine the components of performance that managers can affect, given a strategy and industry operating conditions. Thus, their initial focus is guided by their desire to direct attention to issues of implementation and their effects on performance. The authors attempt to bridge the gap between traditional productivity measures and difficult-to-measure financial performance by developing a set of value creation components as an intermediary set of performance indicators. Based on pilot interviews, these indicators reflect effective performance in ways that are more meaningful than the more traditionalmeasure of productivity, as they are the goals toward which bank management strives. The key values the study attempts to measure are customer convenience, precision, efficient cost structure, adaptability and market penetration. The survey conducted by the research team benchmarks two types of management decisions that are presumed to drive these outcomes. The first set of management choices are implementation choices, human resources choices, technology implementation processes and product/servicedelivery processes. The second set of choices relates to management infrastructure, resource management processes, the information architecture of the firm, the performance management and control systems and the organizational structure of the firm. Based on interviews and the work of previous productivity studies, the research team developed a pilot survey focused on the practices of the functional areas, business lines, product groups and the retail distribution network. The pilot measured the outcomes and choices made by managers in seven large commercial banks. The pilot results will lead to a large scale survey of practices for the entire retail banking sector. Based on early pilot results, the researchers concluded that managers in consumer financial services firms typically assume that improvement in one area of performance is largely at the expense of decreased performance in other areas. The authors believe this is only partly true. Based on the pilot results, the authors believe that better management practices can move outcomes in a number of areas simultaneously. Through effective process design, use of technology and management of human resources, institutions can improve performance in multiple categories. The successful financial services organizations will be those which find processes and practices that enhance multiple measures of performance. The results of the large scale survey of practices will be available in early 1996.

Inside the Black Box: What Makes a Bank Efficient?

A decade of econometric research has shown that X-efficiency dominates scale and scope as the drivers of inefficiency in the U.S. banking industry. However, this research falls short in explaining the causes of the high degree of X-efficiency in the industry. This paper summarizes a four-year research effort to understand the drivers of this inefficiency. Key findings from this research, based on the most comprehensive studies to date of management practices in the retail banking industry, give insight into the drivers of X-efficiency. The paper provides a comprehensive framework for the analysis of X-efficiency in financial services. This paper was presented at the Wharton Financial Institutions Center's conference onRetail Banking, Services, Efficiency, Technology Management, Human Resource Management

Pre-Merger Localization of Gravitational-Wave Standard Sirens With LISA I: Harmonic Mode Decomposition

The continuous improvement in localization errors (sky position and distance) in real time as LISA observes the gradual inspiral of a supermassive black hole (SMBH) binary can be of great help in identifying any prompt electromagnetic counterpart associated with the merger. We develop a new method, based on a Fourier decomposition of the time-dependent, LISA-modulated gravitational-wave signal, to study this intricate problem. The method is faster than standard Monte Carlo simulations by orders of magnitude. By surveying the parameter space of potential LISA sources, we find that counterparts to SMBH binary mergers with total mass M~10^5-10^7 M_Sun and redshifts z<~3 can be localized to within the field of view of astronomical instruments (~deg^2) typically hours to weeks prior to coalescence. This will allow targeted searches for variable electromagnetic counterparts as the merger proceeds, as well as monitoring of the most energetic coalescence phase. A rich set of astrophysical and cosmological applications would emerge from the identification of electromagnetic counterparts to these gravitational-wave standard sirens.Comment: 29 pages, 12 figures, version accepted by Phys Rev

Rotordynamic coefficients and leakage flow of parallel grooved seals and smooth seals

Based on Childs finite length solution for annular plain seals an extension of the bulk flow theory is derived to calculate the rotordynamic coefficients and the leakage flow of seals with parallel grooves in the stator. Hirs turbulent lubricant equations are modified to account for the different friction factors in circumferential and axial direction. Furthermore an average groove depth is introduced to consider the additional circumferential flow in the grooves. Theoretical and experimental results are compared for the smooth constant clearance seal and the corresponding seal with parallel grooves. Compared to the smooth seal the direct and cross-coupled stiffness coefficients as well as the direct damping coefficients are lower in the grooved seal configuration. Leakage is reduced by the grooving pattern

Long distance mode choice and distributions of values of travel time savings in three European countries

The study presented in this paper uses Stated Preferences (SP) data on mode choice collected as part of a recent survey on long distance travel u n dertaken in three European countries. The purpose of this article is twofold. It aims at exploring the impacts of the choic e of mixing probability distri butions while accounting for unobserved taste heter ogeneity and it aims at focusing on the derived estimation of the distribu tions of values of travel time savings (VTTS). We compare eleven distributions, each having particular properties in terms of domain, location, scale, and shape. Due to the repetiti ve nature of the SP experiments, we estimate mixtures of Multinomial Logit (MNL) models for panel data. The results show that the mixing distributions differ from one country to another, suggesting existence of European disparities as it regards long - dista nce mode choice. The results also show that long - distance travellers pay a lot more attention to access and egress travel times to and from the main mode than to total travel time with the main mode

Correlation between In Vivo and In Vitro Efficacy of Antimicrobial Agents against Foreign Body Infections

Implant-associated infections are often resistant to antibiotic therapy. Routine sensitivity tests fail to predict therapeutic success. Therefore experimental in vitro tests were sought that would better correlate with drug efficacy in device-related infections. The activity of six different antibiotics against methicillin-resistant Staphylococcus epidermidis was investigated. In vivo studies were performed with the guinea pig tissue-cage animal model; in vitro studies with minimum inhibiting and bactericidal concentrations, time-kill studies of growing and stationary-phase microorganisms, the killing of glass-adherent S. epidermidis. Drug efficacy on stationary and adherent microorganisms, but not minimum inhibiting concentrations, predicted the outcome of device-related infections. Rifampin cured 12 of 12 infections and was also the most efficient drug in any experimental in vitro test. Similarly, the failure of ciproftoxacin to eradicate foreign body infections correlated with its low efficacy on stationary-phase and adherent S. epidermidi

Rendering Non-Euclidean Space in Real-Time Using Spherical and Hyperbolic Trigonometry

We introduce a method of calculating and rendering shapes in a non-Euclidean 2D space in real-time using hyperbolic and spherical trigonometry. We record the objects’ parameters in a polar coordinate system and use azimuthal equidistant projection to render the space onto the screen. We discuss the complexity of this method, renderings produced, limitations and possible applications of the created software as well as potential future developments

Constraints on the origin and evolution of magmas in the Payún Matrú Volcanic Field, Quaternary Andean Back-arc of Western Argentina

The Payún Matrú Volcanic Field (Pleistocene-Holocene) is located in the Andean back-arc of the Southern Volcanic Zone, western Argentina, and is contemporaneous with the Andean volcanic arc at the same latitude. It includes two polygenetic, mostly trachytic volcanoes: Payún Matrú (with a summit caldera 8 km wide) and Payún Liso (a smaller stratovolcano). The volcanic field includes about 200 scoria cones and alkali basaltic and trachybasaltic lava flows, forming two basaltic fields around Payún Matrú. New 40Ar¯39Ar ages extend the activity of Payún Matrú up to 700 ka. The major and trace element and Sr-Nd isotopic compositions of the basaltic lavas and Payún Matrú rocks indicate that the trachytes of Payún Matrú are the result of fractional crystallization of basaltic parent magmas without significant upper crustal contamination, and that the basalts have a geochemical similarity to ocean island basalt (La/Nb=0·8-1·5, La/Ba =0·05-0·08). The Sr-Nd isotopic compositions of the basaltic to trachytic rocks range between 0·703813 and 0·703841 (87Sr/86Sr) and 0·512743 and 0·512834 (143Nd/144Nd). Mass-balance and Rayleigh fractionation models support the proposed origin of the trachytes, and an assimilation-fractional crystallization model indicates a low degree of upper crustal contamination in the youngest trachytes. Magnesium numbers (45-55) and contents of Ni(<20-90 ppm) and Cr (30-180 ppm) in the lavas in the basaltic fields indicate that these are not primary magmas. The data also suggest that the basaltic lavas originated in the asthenospheric mantle, probably within the spinel stability field and beneath an attenuated continental lithosphere in the back-arc area. The lack of a slab-fluid signature in the Payún Matrú Volcanic Field rocks, along with unpublished and published geophysical results (mantle tomography and electrical conductivity anomalies) suggest that magmas were generated by decompression-induced melting of upwelling mantle.Facultad de Ciencias Naturales y MuseoCentro de Investigaciones Geológica

Water birth: is the water an additional reservoir for group B streptococcus?

Objective: Water birth became popular in the last years, despite the fact that many questions like the risk of infection for the newborn remain unanswered. Group B streptococcal (GBS) infections in the newborn remain a challenge in obstetrics and neonatology. Method: We conducted a prospective trial to study the impact of water birth on the colonization rate of the bath water and, more importantly, the GBS-colonization rate of the newborn. Result: After water birth the bath water was significantly more often colonized with GBS than after immersion followed by a delivery in bed. The newborns, however, showed no difference in GBS colonization and there was even a trend towards less GBS colonization of the newborn after a water delivery. Conclusion: Regarding GBS colonization of the newborn during water birth there might be a wash out effect, which protects the children during the deliver