bluuebunny/crossref_metadata_2025 huggingface dataset:
An integrated geotechnical study of UK mudrocks
Authors: Wilkinson S.  , Brosse A.  , Fenton C.H.  , Hosseini Kamal R.  , Jardine R.J.  , Coop M.R.
Published: February 2025

Mudrocks evolve from soft, predominantly marine sediments, deposited with very high moisture contents, to fissile shales or cemented claystones. The eventual structure of each mudrock is dependant both on the initial condition of sedimentation and the changing environments into which they are placed as they evolve. The anisotropy, strength and stiffness of each mudrock are a reflection of its microstructure at the time of testing. For example, deep burial eventually produces highly aligned fabrics and calcite-rich fluid-flow produces highly cemented materials. As these fine-grained sediments are subject to increasing depth of burial they will pass through a stiff soil – weak rock transition, eventually becoming a lithified sedimentary rock. The Jurassic and Cretaceous mudrocks of the UK were deposited in similar, low-energy geological environments. As well as their depositional setting, the structure of these materials is controlled by their differing sediment sources, climatic conditions, and postdepositional histories. In particular, the detailed burial and subsequent uplift history experienced by each mudrock will determine how its original depositional structure is altered. The mechanical behaviour of younger mudrocks in the UK, such as the Eocene London Clay, has been studied extensively (Geotechnique, 2007). This paper presents a comparable study of the material properties of the older, more deeply buried, Gault, Kimmeridge, Oxford and Lias Clays. The effect of microstructure, and hence geological history, on the geotechnical properties of these mudrocks are studied in detail. The programme of investigations undertaken by a team from Imperial College London included: detailed geological evaluation, in situ testing, high quality sampling, index tests, advanced mechanical tests and quantification of microstructure through innovative scanning electron microscope fabric analysis.
Classification et caractérisation d'une craie blanche sénonienne pour la réalisation de deux tranchées de grande profondeur
Authors: Haghgou M.
Published: February 2025

La construction de la Ligne LGV Est européennea comporté la réalisation (au sud de Reims) de deux tranchées de grande profondeur dans la craie blanche : la tranchée raidie de «Trois Puits »de 1500m de longueur et 28 m de profondeur, et la tranchée de Taissy de 1700 m de longueur et 27 m de profondeur. Ces ouvrages étaient implantés dans la craie blanche sénonienne, avec des épaisseurs variables et par endroit importantes de craie altérée. Pour la conception et l'optimisation de ces ouvrages, il s'est avéré nécessaire de procéder à une classification puis à une caractérisation mécanique des différents faciès de la craie plus détaillées que celles initialement envisagées dans le cadre du projet.
Application of a constitutive model for structured soils in hard soils
Authors: Belokas G.  , Kavvadas M.
Published: February 2025

The combination of the micro- and macro- structural characteristics of hard soils – soft rocks control their mechanical behaviour. In the absence of macro fissures, the micro structural characteristics have a dominant role and the use of soil mechanics approaches surpass those of rock mechanics. In particular, the concept of soil structure is applicable to the modelling of their mechanical behaviour. To portray this, the recently proposed constitutive Model for Structured Soils – 2 (MSS-2) was applied to the modeling of the laboratory test data of a hard soil (Todi clay). The model simulated satisfactorily the mechanical behaviour of both reconstituted and natural soil samples.
Research on hydraulic heaves at excavations with surcharge filters
Authors: Schober P.  , Boley C.  , Odenwald B.
Published: February 2025

When designing deep excavation pits next to waterways that are still being operated, verifying hydraulic heave safety is crucial to determine the necessary length of the pit walls. To reduce their embedment depth, a surcharge filter can be installed. However, studies based on numerical groundwater computations show that verification standards for hydraulic heave safety are not applicable for excavation pits with an installed surcharge filter. Standard approaches neglect significant vertical flow below the wall toe. A method which considers these flow forces was developed based on the numerical flow computations to determine reliably the necessary thickness of the surcharge filter. To examine this theoretical approach and the failure mechanism, several laboratory tests were performed which were evaluated with various methods.
Hydro-mechanical characterization of Jurassic marls to study load degradation
Authors: Muralha J.  , Caldeira L.  , Cardoso R.  , Maranha das Neves E.
Published: February 2025

Mechanical properties of soft rocks such as marls are strongly affected by suction, directly connected with wetting and drying cycles resulting from climate actions. An extensive experimental programme was carried out in order to characterize the physical and mechanical properties of Abadia marls, used in the A10 motorway near Arruda dos Vinhos (Portugal). The experimental programme consisted of laboratory unconfined compression and Brazilian splitting tests, oedometric tests and triaxial tests, all of them performed under controlled suction.
Méthode de dimensionnement directe des pieux basée sur l'essai de chargement de pointe
Authors: Reiffsteck Ph.  , Ali H.  , Baguelin F.  , van de Graaf H.  , Bacconnet C.  , Gourvès R.
Published: February 2025

Le pénétromètre statique, lors de l'essai de chargement de pointe réalisé par paliers jusqu'à la résistance de pointe, présente de grandes similitudes avec un essai de chargement de pieu. Il est donc possible d'extrapoler une méthode de dimensionnement directe utilisant la résistance de pointe et le frottement latéral mesurés par la pointe électrique pour calculer le coefficient de pointe et le frottement latéral unitaire. Nous proposons dans cette communication une nouvelle approche transformant les courbes de chargement et celles de mobilisation de frottement d'un essai de chargement de pointe point par point en courbe chargedéplacement d'un pieu dans les limons et les sables. Cet article présente une approche pratique pour l'évaluation et la normalisation des courbes t-z, la méthode de conception directe proposée pour la prévision du tassement et une comparaison avec des essais de chargement de pieux instrumenté du site de Limelette dans des sables légèrement argileux.
Consolidation of extremely soft mud for the A-380 factory in Hamburg – long time experience
Authors: Chaumeny J.-L.  , Kirstein J.  , Reiner J.
Published: February 2025

The new Airbus plant in Hamburg (Germany) was built on the soft soil of the river Elbe, which is characterized by mud on top and different layers of clay, soft clay, gyttja and peat below.
Better Quality in Healthcare Through Gamified Simulation Based Skill Training Application
Authors: Tancredi Weronika  , Wintell Mikael  , Lindsköld Lars
Published: February 2025

Although the screening of abdominal aortic diameter helps to identify men with abdominal aortic aneurysm and saves lives, there is need to coordinate and synchronize screening personnel's way to work. This article describes the design of a game based skill training application that could give the screening personnel an additional opportunity to refine measuring of abdominal aortic diameter in ultrasound images. The design work follows the steps of the Goal Directed design process. Consequently, the design activities are divided into six phases: the Research, Modelling, Requirements Definition, Framework Definition, Refinement and Development support. The design process described in this paper finishes with usability testing of an interactive prototype. The evaluation of the design was conducted with end users by studying their subjective ratings and performance on given tasks. The overall results of the usability testing show that the interactive prototype of the skill training application is not yet fully usable. Consequently, further improvement of the interface design is needed. The identified usability issues and collected qualitative and quantitative material about the interaction between test participants and the interface can guide the next design iteration and lead to more usable design.
Framework Model and Principles for Trusted Information Sharing in Pervasive Health
Authors: Ruotsalainen Pekka  , Blobel Bernd  , Nykänen Pirkko  , Seppälä Antto  , Sorvari Hannu
Published: February 2025

Trustfulness (i.e. health and wellness information is processed ethically, and privacy is guaranteed) is one of the cornerstones for future Personal Health Systems, ubiquitous healthcare and pervasive health. Trust in today's healthcare is organizational, static and predefined. Pervasive health takes place in an open and untrusted information space where person's lifelong health and wellness information together with contextual data are dynamically collected and used by many stakeholders. This generates new threats that do not exist in today's eHealth systems. Our analysis shows that the way security and trust are implemented in today's healthcare cannot guarantee information autonomy and trustfulness in pervasive health. Based on a framework model of pervasive health and risks analysis of ubiquitous information space, we have formulated principles which enable trusted information sharing in pervasive health. Principles imply that the data subject should have the right to dynamically verify trust and to control the use of her health information, as well as the right to set situation based context-aware personal policies. Data collectors and processors have responsibilities including transparency of information processing, and openness of interests, policies and environmental features. Our principles create a base for successful management of privacy and information autonomy in pervasive health. They also imply that it is necessary to create new data models for personal health information and new architectures which support situation depending trust and privacy management.
Vibrations caused by train traffic and the effect of its mitigation on the quality of living
Authors: Auvinen T.
Published: February 2025

Railway traffic induced vibrations in dwellings often cause irritation or disturb the inhabitants. Mitigation has been performed, and measurements prove their effectiveness. The effect of vibration countermeasures on the quality of living however has not been studied earlier. The objective of the study was to evaluate the effects of vibration mitigation compared to the increase of inhabitant satisfaction, would the halving of vibration levels lead to a doubling of satisfaction? The investigation was done by means of a literature study, vibration measurements and written surveys with the financial aid of the Finnish Rail Administration. The testing was carried out in Raunistula, a suburb of Turku, in Southwestern Finland. Passing along the side of the residential area, the Toijala-Turku railway line causes vibrations in the surrounding areas affecting the quality of residents' life. To attenuate the vibration, two different structures were constructed, a sheetpile wall and a matrix of lime-cement columns. Typical to the Southwestern region of Finland, the soil in Raunistula consists of a thick layer of clay with low shear strength. This soil type allows large displacements in railway sub-structures, especially if ground supported. Additionally, the low natural frequency and damping coefficient of clay lead to minimal attenuation and widespread effects in the surrounding area. The level of vibrations and residents' satisfaction was evaluated prior to construction. After the installation of the aforementioned barriers, a new round of measurements and surveys was performed in order to find out how the mitigation succeeded. Results were satisfactory, the greatest amount of mitigation was achieved nearest to the track and comments of a rise in the quality of living were achieved. The mitigation however was limited to a certain distance from the track. Farther away, partly due to other sources of vibrations and noise, the mitigating effect of the structures was negligible. The results of both the surveys and measurements show an improvement of 30 to 50 %, confirming the hypothesis that inhabitants' satisfaction increases as much as the intensity of vibration decreases.
Ground improvement using the vibro-stone column technique
Authors: Kosho A.
Published: February 2025

The vibro stone columns technique is one of the most used techniques for ground improvement processes all over the world. In recent years this technique is also used in Albania. For the first time in our country this method is used for ground improvement at Ferry Terminal of Durres, which is the biggest harbour of Albania. In this case the technique is used to reinforce silty clay and silty sand soils. There are two methods of construction in the vibro replacement technique named: the wet method and the dry method. In Durres Ferry Terminal building and yard infrastructure the dry method is used. The paper outlines the technique, the ways of application in different types of soil, and settlement and bearing capacity calculations for this case.
Strategic Jet Engine System Design in Light of Uncertain Fuel and Carbon Prices
Authors: Langmaak Stephan  , Scanlan James  , Wiseall Stephen
Published: February 2025

Since the Wright brothers took to the skies over 100 years ago, aviation has been powered by fossil fuels. This dependency will not be markedly reduced within the next two decades despite higher and more erratic fuel prices that result from increasingly restricted access to crude oil. Climate change will also force regulators to increase the price of CO2emissions so that there is an even greater incentive to operate fuel efficient aircraft. This project therefore aims to investigate how the profit generated by a short-range jet engine can be made robust to uncertain fuel and carbon prices in 2030 by applying the Surplus Value Methodology in conjunction with Robust Design techniques.
Evaluating Design Decisions in Real-Time Using Operations Modelling
Authors: Schumann Benjamin  , Scanlan James  , Takeda Kenji
Published: February 2025

Using operational simulations during the early design phase has been largely neglected within the aerospace industry. This paper suggests that an operational simulation should be used twofold by designers during the design process to improve a product. First, it presents how an operational simulation can be used to react to customer specifications. Second, its active use as a design decision support tool is portrayed. Results are found by means of two case studies recreating the operational life of a Search-and-Rescue Unmanned Air Vehicle developed in parallel at the University of Southampton. The simulation's ability to act as a decision support tool is explored by conducting a fuel weight optimization. Reactive capabilities are explored by calculating the surplus value of using UAVs. This exemplifies the derivation of product specifications as the simulation reveals the value and hence usefulness of supplied customer specifications. It is shown that operational simulations benefit designers and overall product value by analysing product specifications and guiding designers to more informed design decisions.
Validation of a new method for ultrasonic structural health monitoring using advanced signal analysis
Authors: van Langen P.J.  , de Boer R.J.  , Brusche J.T.  , ten Donkelaar P.T.  , Sprik R.
Published: February 2025

This paper presents the results of research on a new method for the monitoring of structural health using ultrasound. Conventional ultrasonic methods use the damping of the first arrival of the echo to determine imperfections, whereas this method uses the total complex echo, which has been subjected to multiple scattering and deflections within the tested material. It is experimentally demonstrated that the method works for health monitoring of a composite flat plate. A reference signal of an undamaged plate was recorded, which was correlated with recorded control signals of a damaged and a doubly damaged plate. To quantify this correlation the parameter fidelity was used. As the control signals are correlated with the reference signal the correlation is supposed to decrease as the plate is damaged and decrease further as the plate is doubly damaged.
Influence of Vertical Geodrains on Consolidation Characteristics of Soft Clays Using Oedometer
Authors: Vrajlal Shah Manish  , Shroff A. V
Published: February 2025

Paper presents the detail experimental study through inward radial drainage of remolded kaolinitic clay to a central circular prefabricated vertical Geodrains to assess the consolidation characteristics using large size modified hydraulically pressurized oedometer. Prefabricated vertical coir-jute geodrain, polypropylene fiber drain and sandwick drain of ‘n’(ratio of drain dia. to sample dia) values equal to 16.93 & 21.71 are investigated. The concept of circular section for the drain has been used purposefully to analyise the results using Authors non-linear theory of consolidation. Time – settlement & Time – pore pressure dissipation observations were recorded under different applied stress so as to compute average degree of consolidation using the theoretical solutions developed by the authors. SEM analysis was carried out to study tortousity effect (particle orientation), deformation characteristics and soil-drain interface at the end of each load. Scanning electron microscopy analysis is carried out on consolidated samples to study deformation pattern of drain and at clay-drain interface. From the results it was concluded that coirjute drain of ‘n’ equal to 16.93 shows better efficiency in compare to other drain materials. The authors equal strain solution shows a fair agreement between measured and predicted values.
Study on Horizontal Bearing Capacity of a Skirted Suction foundation in Layered Soils
Authors: Wang Mei  , Li Jing-pei  , Li Da-yong
Published: February 2025

Suction anchors are currently used as a mooring in a variety of floating structures, marine platforms, and the offshore wind turbines has been successfully adopted as well. This paper aims to examine the horizontal bearing capacity of a new form of suction foundation proposed by the third author, skirted suction foundation for offshore wind turbines. The influences of some parameters such as the aspect ratios and thickness of the soil layers on the horizontal bearing capacity are analyzed. The results are proved to be effective way to enhance the horizontal bearing capacity by increasing aspect ratios of the skirted suction foundation, and also illustrate that proposed new form of suction foundation for the offshore wind turbines is feasible.
On the extension of a unified sand model to three dimensional stress conditions
Authors: Chung Ai B.  , Ling Hoe I.
Published: February 2025

The unified generalized plasticity sand model proposed by Ling and Yang (2006) predicted very well the behavior of sand at different initial densities and confining pressures with only one set of parameters. It was calibrated against limited stress paths in (p, q) plane, primarily for triaxial compression tests. In order to make the model more relevant for boundary value problem analysis, the framework of this model is extended and calibrated for the general stress conditions. This study extended the based model framework and compared the simulations with a series of drained true triaxial test results of Fuji River sand under different stress paths in octahedral plane.
History of Horizontal Anchor Plates Based on Experimental Works in Cohesion less Soil
Authors: Niroumand H.  , Kassim Kh. A.  , Nazir R.
Published: February 2025

Buried anchors have been used for thousands years to stabilize structures. Anchor plates may be made of steel plates, precast concrete slabs, poured concrete slabs, timber sheets and so forth. This paper presents the history of anchor plates in experimental works in cohesion less soils due to different researches by last researchers from first research until now. The role of this last experimental research has focused on predicting anchor behavior and force in cohesion less soil. Although there are not entirely sufficient substitutes for full-scale field testing, tests at laboratory scale have the advantage of allowing close control of at least some of the parameters encountered in research. These anchors can be installed by excavating the ground to the required depth and then backfilling and compacting with good quality cohesion less soils. The results are involved of laboratory testing that they are typically problem specific and they are difficult to extend to field problems with different material or geometric parameters in field scale. The paper observed that the ultimate uplift capacity is dependent on the relative friction angle, density based on loose or dense conditions and the depth ratio of embedment.
The use of DInSAR techniques to analyse ground deformations and related effects to buildings
Authors: Cascini L.  , Ferlisi S.  , Peduto D.  , Fornaro G.
Published: February 2025

In the last decade the monitoring of ground deformations associated with subsidence or slow-moving landslide phenomena has been proved to benefit from innovative techniques such as Differential Interferometry Synthetic Aperture Radar (DInSAR). With reference to well-documented case studies in Campania region (southern Italy), the role that the geotechnical approach can play in the interpretation of remote sensing data is highlighted via the application, at different scales, of two general frameworks which can valuably link the interpretation of DInSAR data to the knowledge of both the phenomena and their effects on structures/infrastructures.
Sliding of highway embankments along riverbanks on soft ground in An Giang Province, Vietnam: A case study
Authors: Tran-Nguyen Hoang-Hung  , Nguyen Cuong V.H.  , Tran Hoang H.  , Le Viet X.
Published: February 2025

Sliding of highway embankments along riverbanks on soft ground has caused serious socio-economic loss annually in An Giang province, Vietnam. However, the nature of sliding problems has not been thoughtfully and systematically investigated. This study aims at better understanding of the factors causing the sliding and the mechanism of the sliding. Several analyses were conducted using the Slope/W 2007 software with the three selected site data: Binh My, Chau Doc, and Nhon Hoi which locate along the Hau river in An Giang province. The numerical results indicate that high fluctuation of groundwater and river water levels remarkably influence the stability of highway embankments along riverbanks. The sliding increases with increasing human activities along riverbanks. The toe of embankment slopes eroded in the dry season due to the lowest river water level triggers overall instability of embankments, and activates translational and rotational sliding. The climate change significantly increases sliding locations along the Hau river and Tien river, the branches of the Mekong river when it reaches the Vietnam-Cambodia border.
Stiffness nonlinearity and anisotropy of stiff clays observed during isotropic consolidation
Authors: Yimsiri Siam  , Soga Kenichi
Published: February 2025

The stiffness nonlinearity and anisotropy of natural London Clay and Gault Clay under isotropic consolidation are investigated using a triaxial apparatus incorporated with local strain measuring systems. Isotropic consolidation tests are performed on both vertically- and horizontally-cut specimens. The stiffness degradation curves of bulk modulus (Ksec/p'-ϵvol) can be obtained and the anisotropy can be observed from independent measurement of incurring vertical and horizontal strains. The anisotropy of intermediate-strain stiffness can be interpreted from Young's modulus degradation curve (Esec/po'-ϵa) derived from isotropic consolidation data. The results show that, under isotropic consolidation, the undisturbed London Clay and Gault Clay specimens are stiffer in the horizontal direction. It is also found that Gault Clay has smaller bulk modulus but has higher degree of stiffness anisotropy than those of London Clay.
Small strain stiffness and yielding property of cement-mixed soil in drained triaxial compression
Authors: Kiyota Takashi  , Maeda Yohei  , Ezaoui Alan  , Tatsuoka Fumio
Published: February 2025

To evaluate the effects of ageing and large-scale yielding on the small-strain stiffness of moist compacted cement-mixed soil, a series of drained triaxial compression (TC) tests were performed. The specimens were cured initially unconfined for different periods and at an anisotropic stress state during TC loading for two days. The small-strain stiffness was evaluated during otherwise TC loading towards failure. As the curing period increases, the small strain stiffness values obtained by static and dynamic measurements at respective stress states increase associated with development of yield locus (YL). The small strain stiffness increases with the confining stress until the current stress level reaches the current YL that has developed by strain-hardening and curing, while it starts decreasing when the current stress level exceeds the current YL. These trends are more clearly observed with dynamically measured values, which are generally higher than statically measured values reflecting more the stiffness of stiffer local parts in the specimen.
Effects of wetting history on the yielding of cement-mixed clay exhibiting ageing
Authors: Deng Jianliang  , Nawir Hasbullah  , Tatsuoka Fumio  , Kuwano Jiro
Published: February 2025

Effects of wetting, coupled with positive ageing effects, on the yielding of clay were evaluated by performing a series of non-standard one-dimensional (1D) compression tests on cement-mixed kaolin prepared air-dried. A wide variety of water content history was applied to the specimens carefully controlling the water supply rate at each sustained loading stage during otherwise monotonic loading at a constant strain rate. The compression rate increases when yielding is enhanced by wetting and decreases when yielding is restrained by ageing due to cement-hydration, while positive ageing effects develop with time by wetting and the viscous effects develop whenever yielding takes place. Highly complicated stress-strain-time behaviour during these processes can be accurately simulated by a non-linear three-component elasto-viscoplastic model incorporating the effects of wetting and ageing.
Evaluating Deformational Behaviors of Crushed-Rock-Soil Mixtures Using Field and Large-scale Resonant Column Testing
Authors: Park In-Beom  , Mok Young-Jin  , Park Chul-Soo
Published: February 2025

Crushed-rock-soil-mixtures, produced from adjacent cutting or tunneling, are being recycled to load-bearing compaction fills in the recent construction of high ways and high-speed railways in mountainous areas. The objective of the paper is to develop a resilient modulus (ER) prediction model for the compaction fills of recycled crushed-rock-soil-mixtures. The evaluation of ER, using the “orthodox” repeated loading tri-axial test, is not realistic for such a large-grain-size material. The realistic alternative is to utilize the well-developed techniques which are currently used for measurements of subtle different modulus, such as shear modulus (G). The prediction model was developed by: (1) adopting the modified hyperbolic model of shear modulus curve, and (2) determining the model parameters (AE, nE, ϵrand a) from in-situ measured Gmaxand the reduction curves of modeled materials using the large free-free resonant column tests. The values of AEincrease from 8731 to 13135 as the overall grain distribution (represented by Dmax, D50and Cu) varies. The values of nEfall in the range from 0.35 to 0.47 and turn out to be not much affected by D50in general. For determination of the model parameters ϵrand a, the modeled materials were reconstructed by shifting the typical gradation curve of the original material. The effect of confining pressure on the parameters is minimal and in turn the parameters were evaluated from the mean curve. Also the effect of grain size turns out to be insignificant as long as Cumaintains in the gradation shifting. The values of ϵrand a proposed are 0.0135 and 0.80, respectively, for the typical crushed-rock-soil-mixtures. It should be noted that, if the gradation curve widely stretched including quite an amount of fines, scalped specimens may be used to evaluate the model parameters of such a “dirty” material.
Real Options and Variational Inequalities
Authors: Bensoussan Alain  , Hoe SingRu(Celine)  , Koo Hyeng Keun
Published: February 2025

The timing of capital investments is a vital decision faced by a firm's managers. Traditional discounted cash flow valuation methods are limited to situations in which investment is “now or never”. Real options models have been developed to overcome these limitations, allowing analysts to incorporate flexibility in their capital spending decisions. Unlike financial options, exercise of a real option by one firm may directly affect the value of that same option to a competing firm. Strategic interactions present significant challenges that may render classical models inadequate to the task of managing firm's capital investments. This chapter describes and summarizes the framework and the solution to the classical real options model as well as its integration with competition when the flexibility is limited to timing of investments.
Financial Engineering and Agency Problems
Authors: Sung Jaeyoung
Published: February 2025

In this chapter, we briefly review two important recent financial crises, S&L and subprime mortgage crises, and discuss why moral hazard issues should be carefully considered in formulating financial engineering problems. We explain how ignoring moral hazard can lead to the overvaluation of assets and to under-investment problems passing up positive net present value projects. In particular, if misaligned incentives are widespread in the industry, inducing managers to excessively compete over similar investment opportunities, the industry can collapse with a nontrivial probability, as systematic risks common in the industry move in unfavorable direction. Even when incentives optimally designed, agency problems still fundamentally affect the whole financial markets in equilibrium, and thus financial engineering problems.
Real Options: A Framework of Optimal Switching
Authors: Tang Shanjian  , Koo Hyeng Keun
Published: February 2025

In this chapter we provide an overview of the new general theory of real options developed by Tang and coauthors. We define a real option as an investment project's managerial flexibility which grants the firm the right to choose new modes among a given finite set of modes to respond to the resolution of uncertainty over time. The choice must be made over a sequence of discretionary stopping times, and to change the mode of operation the firm must pay a cost. Mathematically, the problem of valuing a project involving real options and finding the optimal policy is formulated as an optimal control problem with discrete adjustment.
Optimal Consumption and Investment in the Presence of a Stopping Choice
Authors: Shim Gyoocheol  , Koo Hyeng Keun
Published: February 2025

In this chapter we survey recent research on models of consumption and investment in the presence of stopping choices, such as choices of retirement times. The problems in these models are mixtures of problems regarding consumption/investment and those regarding choices of stopping times. We describe the models, emphasizing their common features, and explain two solution techniques: the dynamic programming approach and the martingale/duality approach. We also explain a common economic intuition derivable from the solutions to the models. Namely, the possibility of stopping is similar to a real option and induces investors to consume less and take more risk than they would in the absence of such possibility.
Stochastic Control Methods for the Joint Optimization of the Risk and Dividend Policies of a Firm
Authors: Cadenillas Abel
Published: February 2025

We consider a firm that simultaneously controls its risk and dividend policies. However, a reduction in risk generates a reduction in its potential profits. The management also decides the times and the amount of dividends to be paid out to the shareholders, taking into account that there are fixed costs and taxes associated with each dividend payment. We present a survey that shows how the methods of mixed classical-impulse stochastic control can be applied to model and solve these problems. We also present some open problems.
Market Microstructure
Authors: Lee Kiseop
Published: February 2025

Market microstructure has been a very popular study topic for the last half century, but a financial engineering approach in this area is relatively new. In this chapter, we review recent developments of market microstructure studies using financial engineering techniques. These includes general equilibrium in continuous time, modeling of market frictions such as liquidity risk and transaction cost, modeling of limit order book dynamics which directly compensates classical bid and ask spread studies, high frequency (tick by tick) price dynamics and microstructure noise, and news arrivals and information asymmetry.
GAMES: A General Architecture for Medical Expert Systems
Authors: Stefanelli M.  , Bellazzi R.  , Berzuini C.  , Bugliesi M.  , Calzadilla J.  , Hunter J.  , Kolary P.  , Lanzola G.  , Leaning M.  , Mantas J.  , Moustakis V.  , Quaglini S.  , Ramoni M.  , Ruggieri C.  , Zambon F.
Published: February 2025

A suitable General Architecture for Medical Expert Systems (GAMES) has been defined in terms of generic tasks (diagnosis, therapy planning and monitoring) to be executed for developing medical reasoning in a patient's management. Their epistemological structure has been investigated. The GAMES project aims at designing a general architecture for knowledge based systems in medicine. The focus of the project is on the comparison and validation of different approaches in order to implement the generate and test cycle, which represents the basic feature of the epistemological model of medical reasoning we developed.
INFORM: Towards a New Generation of Information Management and Decision Support Systems for High Dependency Environments
Authors: Bowes Claire L.  , Ambroso Claudio  , Carson Ewart R.  , Chambrin Marie-Christine  , Cramp Derek  , Gilhooly Kenneth  , Groth Torgny  , Hunter James R.W.  , Kalli Seppo  , Leaning Mark L.
Published: February 2025

The long-term aim of the INFORM Project is to develop, evaluate and implement a new generation of Information Systems for hospital High Dependency Environments (HDE). Such environments include Intensive Care Units (ICU), Neonatal Units, Burns Units, Operating and Recovery Rooms, and other specialised areas. The INFORM System will integrate Decision Support with on-line, off-line and observed patient data and, in addition, will incorporate and integrate unit management features.
AIM: Paving the Way for Health Care Informatics Standards in Europe
Authors: Villasante Jesús  , Noothoven Van Goor Jaap
Published: February 2025

The 16th May 1991, the Technical Committee 251 of CEN, Comité Européenne de Normalisation, adopted a workprogramme for the development of health care informatics standards in Europe. This is the first detailed action plan and appropriate framework in Europe a for progressing in this field. The AIM Exploratory Action has played a key role in this major achievement, along with other organizations and individuals that contributed enthusiatically. However, the most difficult work is still ahead of us. This paper describes the European situation in health care informatics standards before the AIM Exploratory Action, the contribution of this European Community programme in the domain, and finally and importantly, which could be the keys to continued progress of standardization activities in Europe.
Interpreting Physiopathological States under Environment Temporal Restrictions
Authors: Escalada-Imaz G.  , Jaureguizar-Núñez J.  , Paster-Durán X.  , Fita-Rodríguez G.
Published: February 2025

We describe a computer model for diagnosing physiopathological states in a dynamic and real time environment, in the domain of a Pediatric Intensive Care Unit (PICU). The approach is based on a graph, using several uncertainty propagation and time restrictions rules.
AN ASSESSMENT OF THE VISUAL STATUS OF GUIDE DOG OWNERS IN NORTHERN IRELAND
Authors: Jackson A J  , Murphy P J  , Dusoir T  , Dusoir H  , Murdock A  , Morrison E  , Reid V
Published: February 2025

Only 96 out of an estimated 28,000 registerable visually impaired persons, resident in Northern Ireland, currently make use of guide dogs for the blind. Results from this study indicate that guide dog owners represent a highly motivated sub group of blind persons who have been profoundly visually impaired for prolonged periods of time. The implications of future ophthalmological developments, and of the creation of better educational and employment facilities for the visually impaired, are discussed.
Low Vision Assessment and Training Materials for Use in Developing Countries
Authors: Keeffe Jill  , Lawrence Margaret  , Lovie-Kitchin Jan  , Marshall Keith  , Taylor Hugh R
Published: February 2025

The problems faced by developing countries for low vision assessment and training include the size and distribution of the population in relation to available resources, the lack of appropriate assessment materials, and lack of skills and knowledge in the assessment and rehabilitation of low vision. This paper reports on tests and assessment procedures which have been designed utilising technology appropriate to developing countries. Manuals include information on low vision and suggestions for a vision training program. Together these form a multi-purpose kit. Relevant parts can be selected for screening, identification of children with low vision, a comprehensive assessment of functional vision, or a short assessment for a particular purpose such as mobility. The kit has been used and evaluated in many parts of the developing world to ensure its appropriateness.
Functional diagnosis and rehabilitation in proposals for an information support system for the treatment of the visually disabled
Authors: CAMPO Massimo Ignazio  , TESTA Anna
Published: February 2025

The V.I.RE.P. Project finds its origin in the necessary combination and interaction of different competences (ophtalmology, psychology, rehabilitation and informatics) around the same matter: standardization of the procedures for assessment and rehabilitation of the various types of visual disabilities. A combination and integration of the four fields of research and experience constituted the base for the development of models of data collection, protocols of investigation, patterns of evaluation.
A Surface Modelling System for the Study of Scoliosis
Authors: DURDLE Nelson G.  , HILL Douglas  , ZHANG Zixi  , RASO V.James
Published: February 2025

The trunk deformity associated with scoliosis is considered by many patients and physicians as more important than the spinal deformity itself. For this reason it is important to access the three-dimensional characteristics of the surface deformity. A surface modelling system has been developed to study this surface deformity. This system is comprised of software modules running on an IBM RISC6000 engineering workstation. This system displays a realistic model of the trunk which can be rotated and viewed from any orientation. The surface modeller contains three major components; systems for determining the boundary of the trunk data, for modelling the trunk using triangles and for display and manipulation of trunk images. Triangles were chosen for their computational simplicity which minimizes the time to construct and move the 3-D image of the trunk. Boundary generation from discrete data points is ill-defined and subjective. Any surface model of the trunk requires the boundary to be defined. Otherwise, triangles would be placed in regions which are not part of the trunk surface. A boundary determination routine has been developed which provides a best estimate of the trunk boundary and then permits the user to interactively eliminate unwanted artifacts. The surface modelling routine uses a modified form of McLain’s algorithm to define the triangles which constitute the surface model. This algorithm was modified to greatly increase its speed and a novel method is used to eliminate triangles which fall outside the boundary. The display provides a realistic three dimensional image of the trunk which appears illuminated from ambient light and spot light sources. Multiple views of the trunk or different trunk images can be shown for comparison purposes. This permits the clinician to compare changes which occur over time in trunk deformity. The software system can simultaneously show a model of the spine or photo image in conjunction with the trunk surface model. This helps relate surface deformity to the underlying spinal misalignment.
High-Resolution Rasterstereography
Authors: HIERHOLZER E.  , DRERUP B.
Published: February 2025

A new method for high-resolution measurement of body surfaces called carrier frequency rasterstereography is presented. In conventional rasterstereography the maximum line density must be limited in order to avoid erroneous image processing. The density may be increased by using modulated raster lines. Phase-sensitive demodulation is possible by means of epipolar rays. By this method high-density raster line patterns are correctly analyzed. The sampling density on the surface is accordingly increased, permitting more accurate measurements of anatomical details such as the spinous processes.
Primary Care Guidelines from an organizational point of view
Authors: ten Hoopen A.J.  , Boon D.A.  , Nutma J.  , de Vries Robbé P.F.
Published: February 2025

Guidelines in primary health care have been developed to reduce assumed and undesired variation in certain aspects of care delivery by professionals. If systematically applied guidelines no doubt effect the quality of care. It is argued however that taking an organizational point of view on quality management yields new requirements with respect to development and application of guidelines. It is considered to be essential for managerial control purposes that guidelines have simple and valid indicators to monitor the actual application and to measure the preferred outcome. It is essential that the choice of guidelines to be implemented in an organization is determined in the context of an explicit plan for quality management.
Tissue Cutting in Virtual Environments
Authors: Song Gyeong-Jae  , Reddy Narender P.
Published: February 2025

We have developed a technique for cutting in virtual environments using interactive moving node finite element models controlled by operator exerted forces on an instrumented cutting tool. Preliminary results, obtained with 2-D models of cutting of linear elastic objects, have demonstrated the feasibility of the technique for tissue cutting in virtual environments.
Integrating Anatomy and Physiology for Behavior Modelling
Authors: DeCarlo Douglas  , Kaye Jonathan  , Metaxas Dimitri  , Clarke John R.  , Webber Bonnie  , Badler Norm
Published: February 2025

In producing realistic, animatable models of the human body, we see much to be gained from developing a functional anatomy that links the anatomical and physiological behavior of the body through fundamental causal principles. This paper describes our current Finite Element Method implementation of a simplified lung and chest cavity during normal quiet breathing and then disturbed by a simple pneumothorax. The lung model interacts with the model of the chest cavity through applied forces. The models are modular, and a second lung and more complex chest wall model can be added without disturbing the model of the other lung. During inhalation, a breathing force (corresponding to exertion of the diaphragm and chest wall muscles) is applied, causing the chest cavity to expand. When this force is removed (at the start of exhalation), the stretched lung recoils, applying pressure forces to the chest wall which cause the chest cavity to contract. To simulate a simple pneumothorax, the intrapleural pressure is set to atmospheric pressure, which removes pressure forces holding the lung close to the chest cavity and results in the lung returning to its unstretched shape.
Searching for Indices of Contractility Is Counterproductive
Authors: Slinker Bryan K.
Published: February 2025

Conceptually, cardiac contractility is the potential for contraction that cardiac muscle possesses by virtue of the physicochemical environment of the muscle cell, e.g., calcium handling and contractile proteins. It is what the muscle (heart) is capable of doing. The search for simple indices of contractility has been an attempt to provide an operational definition of contractility. However, none of the simple indices that have been proposed has been particularly robust, and all have either been abandoned or used with less than originally anticipated enthusiasm. This should not be particularly surprising for two reasons: First, the regulated cardiac pump is not simple. Where the heart functions at any point in the range of the multitude of possibilities available to it will depend on many factors. In addition, requiring simplicity not only flies in the face of the reality of cardiac performance, it almost guarantees that important characteristics of cardiac performance will be excluded from the assessment of contractility. Two, a corollary of the “simplicity” requirement is that an index must also be “loadindependent”. This requirement derives from a recognition of the complexity of cardiac performance--for a simple index to be useful in describing the essential character of a complexly regulated cardiac pump, the complexity either has to be accounted for or not allowed to express itself by holding constant all other factors. The “load-independence” requirement is an attempt to do the latter. However, this requirement also is unrealistic because properties of cardiac muscle that we would view as part of “contractility” are inextricably linked to rate and load (e.g., intervalforce behavior and length-dependent activation). Thus, given the complexity of the regulated cardiac pump, the multiple interacting determinants of cardiac performance, and the marvelous adaptive ability of cardiac muscle, it is not surprising that a robust, simple load-independent index has not been found. For these same reasons, continued searching for a simple index of contractility is likely to be as un-satisfying in the future as it has been in the past. Rather, the complexity of the regulation of cardiac performance begs for a broader view of contractility that includes the complexity in a quantitative multivariate approach that acknowledges the real way the system functions, is regulated, and adapts.
The CEN/TC 257/SC1 -Nomenclature
Authors: Worroll John
Published: February 2025

This report has been prepared to aid understanding of the decisions made by CEN/TC 257/SC1 - Coding systems and nomenclature for medical devices - in preparing the following documents: prENV XXXX Nomenclature - Recommendations for an interim system and rules for a future system, prEN YYYY Nomenclature - Specification for a nomenclature system for medical devices for the purpose of regulatory data exchange.