bluuebunny/crossref_metadata_2025 huggingface dataset:
A Experimental Study on the Seawater Attack Resistance of Micro Silica Grout Material
Authors: Kim Young-hun  , Kim Jin-chun  , Chun Byung-sik
Published: February 2025

In the seawater deposition condition, the corrosion and chemical attack of grouts are similar to those of concrete structure. Used in domestic MSG(Micro Silica Grouting) mixtured large amounts of silicate materials containing as cement powder is 8,000cm2/g of the specific surface area or more due to the high hydration activity and high-strength, high durability, and features, C3A content of less than 5% to meet the standards chemical attack of sea water is evaluated as a cement material. Therefore, in this paper, with excellent sea water attack resistant MSG in combination with rapid hardening mineral is used, those of sea water characteristics were evaluated experimentally. Typically, sodium-silicate minerals or rapid hardening cements are used in domestic. About the homogel specimens with combination of MSG and rapid hardening agents for compressive strength, weight change and length change characteristics were evaluated experimentally, and so we could present the excellent sea water registanf grouts combination.
Frost Heaving Characteristics of Subgrade Soils Using Laboratory Freezing System
Authors: Shin Eun-Chul  , Ryu Byung-Hyun  , Park Jeong-Jun
Published: February 2025

The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing system tests simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is -6 ~ -7°C on average. This chilly weather generates the frost heaving by freezing the moisture of soil and potential damage of the road structure. In the freezing soil, the ice lenses increase the freezing portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure.
Effect of particle fabric on the one-dimensional compression response of Fraser River sand
Authors: Northcutt Sheri L.  , Wijewickreme Dharma
Published: February 2025

One-dimensional compression of sand with lateral stress measurement allows for laboratory determination of the coefficient of lateral pressure at rest, Ko. The present study aims to investigate the role of initial particle fabric in one-dimensional compression and to determine the effect of fabric on the coefficient of lateral pressure at rest in Fraser River sand. One-dimensional compression with lateral stress measurement was carried out on reconstituted Fraser River sand specimens using an instrumented oedometer. In order to construct different particle fabrics, three different laboratory specimen reconstitution techniques were utilized: air pluviation, tamping and vibration. Each one-dimensional compression test was executed in three distinct phases: virgin loading, unloading and reloading. The results from the present study show that specimens resulting from different laboratory reconstitution methods (i.e., different initial particle fabrics) exhibit different one-dimensional compression responses.
Stiffness Anisotropy of Compressible Chicago Glacial Clays during Shear
Authors: Cho Wanjei  , Jung Young-Hoon  , Kim Taesik  , Finno Richard J.
Published: February 2025

The stiffness anisotropy of lightly overconsolidated compressible Chicago glacial clays was investigated with three sets of bender elements. Each specimen was trimmed from high quality block samples taken from an excavation in Evanston, IL. Three sets of bender element tests (GVH, GHHand GHV) were performed before setting up the specimen, during K0consolidation to the in situ vertical effective stress and shearing. Results of bender elements tests obtained prior to shearing show that compressible Chicago glacial clay initially is cross-anisotropic. Propagation velocities measured by bender elements in axial direction after K0reconsolidation and drained creep agrees well with the in-situ shear wave velocity measured by seismic CPT tests. For each of three shear stiffnesses, an empirical correlation was established based on the elastic shear stiffness in a preyield condition. By comparing the empirical correlations with the measured elastic shear stiffnesses in the stress region during shearing, the changes of elastic shear stiffnesses were investigated. Further, the modifications of stiffness anisotropy during shearing were evaluated.
Effects of foams and polymers on the small strain behavior of kaolin
Authors: Zumsteg R.  , Plötze M.  , Puzrin A. M.  , Egli H.  , Walliser A.
Published: February 2025

Soil conditioners such as polymers and foams are often used in earth pressure balanced machines to improve the mechanical properties of the excavated soil and to guarantee safe tunneling with acceptable settlements. In clay soils, foams and polymers are expected to increase compressibility and workability and to reduce soil strength and adhesion potential of the soil mixture supporting the face of the tunnel. Application of conditioners often produces soft soil pastes, which do not behave like solid soil materials but also possess liquid and viscous properties. The detailed working mechanisms and effects on mechanical properties of the used chemicals are still largely unknown. In this paper the drastic effects of a conventionally used polymer and foam on kaolin are investigated. Undrained shear strength measurements using a newly developed vane shear device are analysed. The results show the dispersing power of polymers, increased viscous properties and drastically changed small strain behavior of the mixtures. All these effects are assumed to be a consequence of the reduced attraction forces between clay particles.
Direct shear behavior of sand and tire chips using X-ray CT and DEM simulation
Authors: Tsutsumi Yohei  , Otani J.  , Mukunoki T.  , Chevalier B.  , Takano D.  , Hazarika H.
Published: February 2025

One cost effective application of mixed sand with tire chips is to use them behind retaining structures as reducing earth pressure and to use its highly permeable nature of this type of materials as an agent for reducing liquefaction induced deformation. However, the precise mechanical properties of tire chips and mixed sand with tire chips have not been clarified yet. The objective of this paper is to investigate the shear behavior of tire chips and mixed sand with tire chips. First of all, the direct shear test which is one of the typical tests to obtain strength and deformation characteristic of granular materials was conducted for tire chips, sand and mixed sand with tire chips. Using X-ray CT, three dimensional behaviors of the materials were investigated without any destructions. In order to discuss the deformation and strain from the CT images, one of the common techniques on image analysis called Particle Image Velocimetry (PIV) was used. Here, the distributions of the displacement vectors, shear strain and volumetric strain were measured in each shear displacement level. These direct shear behaviors were also simulated using 3-D Discrete Element Method (DEM) and compared to the experimental results. Finally, the mechanical properties such as deformation and failure in the materials of tire chips and mixed sand with tire chips were precisely discussed based on all the results.
Effect of crushability of Jeju beach sand on CPT and DMT results
Authors: Lee Moon-Joo  , Hong Sung-Jin  , Chae Young-Ho  , Lee Woojin
Published: February 2025

Jeju sand, which contains both siliceous and calcareous materials, is the highly crushable one and has high extreme void ratios due to the grain angularity and intra-particle voids. In this study, a series of CPTs and DMTs are carried out on the specimens reconstituted in a calibration chamber to evaluate the properties of crushable Jeju beach sand. It is observed that the particle crushing during the DMT penetration into the Jeju sand results in the smaller horizontal stress index (KD) and dilatometer modulus (ED). The KD-qc/σv' relation is found to be more dependent on the compressibility of granular particles than the ED-qcrelation. It is concluded that the KDof granular soil is more significantly affected by particle characteristics than EDand qc.
Rock physics model for interpreting dynamic and static Young's moduli of soft sedimentary rocks
Authors: Takahashi Toru  , Tanaka Soichi
Published: February 2025

To interpret dynamic and static Young's moduli of soft sedimentary rocks widely distributed in Japan, the sandy shale model of the binary sand/shale mixture model are applied to the measured Young's moduli obtained from velocity logging data for the dynamic modulus and from laboratory mechanical test data for the static modulus. The Young's modulus for the rock is calculated by the Hashin-Strikman lower bound, Hertz-Mindlin contact model and Gassmann's equation. For modelling static Young's modulus, in the Hertz-Mindlin contact model, the shear modulus is calculated by incorporating the mixture of frictional and frictionless grain contacts into the model. The calculated dynamic and static Young's moduli are well consistent with the measured data for three different soft sedimentary rocks. This result demonstrates that the sandy shale model can be used to predict the static moduli required in civil engineering applications from dynamic ones obtained from seismic velocities.
Parameter calibration of a modified hyperbolic model for sands using pressuremeter test data
Authors: Oztoprak Sadik  , Bolton Malcolm. D.
Published: February 2025

The reduction of shear modulus causes non-linearity before plastic yielding, and this needs to be taken into account in deformation analyses for the performance-based design of geotechnical structures. In this respect, this paper demonstrates the simulations of pressuremeter tests via a non-linear elastic perfectly plastic soil model. A modified hyperbolic model was adopted for the pre-failure part of the stress-strain behaviour, and the Mohr Coulomb soil model was implemented for modelling the post-failure behaviour in FLAC3D. Computed pressure-displacement curves at the cavity wall matched very well with the curves of self boring pressuremeter tests carried out in Thanet sand. A new pressuremeter disturbance correction is used successfully as a means of adjusting and updating the shear modulus. The analysis reveals that this approach is essential for estimating the initial lateral earth pressure coefficient, and is capable of refining the selection of new reduction parameters in the modified hyperbolic model using pressuremeter rebound loops, and of refining values of friction and dilation angles from initial expansion and final contraction curves. Using the modified hyperbolic model in conjunction with pressuremeter test data enables not only calibration, but also optimization of parameters. The simulation of a pressuremeter test enables the engineer to obtain an appropriate combination of soil parameters which can later be utilized to analyze geotechnical structures through the same calibrated model.
A bond model for cemented sands including the effects of cement type
Authors: Yarbakhti P.  , Hamidi A.
Published: February 2025

There are vast zones in nature consists of cemented granular soils. The stress-strain analysis of any structure on these soils and also stability of slopes of this type of material need accurate knowledge of its behavior. In this paper the experimental results are used to develop a new constitutive model for prediction of the behavior of cemented granular soils. The stress-strain behavior of the cemented bonds is combined with that of the uncemented soil using deformation consistency and energy equilibrium equations. The cement content and the cement type were considered as two effective parameters on the mechanical behavior of the cemented bands. In this context that of the soil cemented with different cement types was predicted. The comparison of the stress-strain curve for model with that of the experimental results indicates that the behavior of cemented soils can be predicted with a good and reasonable accuracy by application of the proposed model.
Behavior of mechanical jointed composite piles by field load tests
Authors: Shin Yun-Sup  , Ko Jun-Young  , Jeong Sang-Seom  , Kim Myoung-Mo
Published: February 2025

In the present paper, the behavior of mechanical jointed composite pile, which is composed of the two parts of the upper steel pile and lower concrete pile by a mechanical joint, was studied by field pile load tests and numerical analyses. Field pile load tests were conducted with 5 composite piles so that special attentions were given to the joint behavior of composite piles under varying conditions, such as soil strength, pile length, joint depth, pile diameter, and loading types. The three-dimensional continuum finite element analysis with ABAQUS(ver6.8) was performed to conform the stress transfer and load resistances at the mechanical joint. For verifications of the numerical analyses, three point bending tests are carried out with attaching electric resistance strain gages to inside and outside of the mechanical joint. Based on these results, it is observed that the lateral displacements increase as the distance between the loading point and mechanical joint decrease. From these results, it is acceptable that the behavior of mechanical jointed composite piles is influenced significantly by the mechanical joint depth.
Experimenting with the Instances of the MaxSAT Evaluation
Authors: Argelich Josep  , Li Chu Min  , Manyà Felip  , Planes Jordi
Published: February 2025

We report on a number of experiments on the instances of the MaxSAT Evaluation with the aim of gaining new insights into their computational hardness, answering some questions that have been asked to us as organizers, and evaluating how appropriate are the current settings of parameters such as timeout and available RAM memory. The lessons we have learned from the analysis of the empirical results suggest to introduce several modifications in forthcoming evaluations.
Multinational Undergraduate Team Work
Authors: Van Assche Kristien  , Escudeiro Nuno  , Escudeiro Paula  , Dispert Helmut
Published: February 2025

We believe that a set of tools and curricular activities involving students from different countries, collaborating to complete projects that generate relevant outputs to the community, might improve both students' enthusiasm and their team work and communication skills. That is the mission of the Multinational Undergraduate Team Work project (MUTW). The MUTW methodology is devoted to create and manage future international teams of students who will collaborate in order to develop a solution for a given engineering problem. The methodology encompasses all the timeframe of an edition of MUTW, including preparation of the students' project and its deployment by the teams of students.
Principles of Open Source Software
Authors: Todorova Margarita  , Todorov Georgi  , Jotov Vladimir
Published: February 2025

The main characteristics of open source software and the main principles of writing open source projects are presented in this chapter. The list of open source software applications is also presented. The explanation of Concurrent Version System as a server free software revision control system in the field of software development is also presented. The seminars on Open Source and on CVS, are included in order students to test their knowledge in these fields.
Infrastructures for Knowledge Systems Environments
Authors: Hashimoto Takako  , Henno Jaak  , Jaakkola Hannu  , Šaša Ana  , Thalheim Bernhard
Published: February 2025

Knowledge management has been a hot research issues for decades and resulted in many proposals and some systems that have been supporting information exchange in companies or societies. They failed however to become knowledge systems. With the advent of the internet the knowledge web is going to replace knowledge management. It creates its own challenges but take advantage of all web, information systems and software technology.
Renal cell carcinoma
Authors: Cairns Paul
Published: February 2025

Renal Cell Carcinoma (RCC) has the highest mortality rate of the genitourinary cancers and the incidence of RCC has risen steadily. If detected early, RCC is curable by surgery although a minority are at risk of recurrence. Increasing incidental detection and an ageing population has led to active surveillance as an option for patients with small renal masses. RCC is heterogeneous and comprises several histological cell types with different genetics, biology and behavior. The identification of the genes predisposing to inherited syndromes with RCC has provided much of our knowledge of the molecular basis of early sporadic RCC. Many of the oncogenes and tumor suppressor genes that are mutated leading to pathway dysregulation in RCC remain to be elucidated. Global studies of copy number, gene sequencing, gene expression, miRNA expression and gene methylation in primary RCC will lead towards this goal. The natural history of RCC indicated by candidate precursor lesions, multifocal or bilateral disease, growth rate of small renal masses under surveillance, and high risk populations provide insight into the behavior of this disease. The use of molecular markers for early detection and prognosis merits more attention with ongoing advances in omics technologies. This review focuses on early RCC, that is disease confined within the renal capsule.
Making Standardization Contribute to the Protection of People and Democratic Values
Authors: Rannenberg Kai
Published: February 2025

In 2006 ISO/IEC JTC 1/SC 27 “IT Security techniques” established Working Group 5 “Identity Management and Privacy Technologies”. This text describes the reasoning to have this Working Group within SC 27 and introduces WG 5 and its projects including the recently published privacy framework (ISO/IEC 29100) and framework for identity management, Part 1 (ISO/IEC 24760-1) as well as WG 5's liaison partners and future work.
Torre Iberdrola, Bilbao, Spain
Authors: Zemborain Axel
Published: February 2025

After winning an international competition held in 1993 to design the Master Plan for the Abandoibarra area of Bilbao, Pelli Clarke Pelli Architects designed its main compositional element: Torre Iberdrola. The tower was conceived as a softly rounded triangle in plan that tapers upwards towards the sky. Access to the building is through a sculpturally shaped glass lobby which encloses a large landscaped area. The tower is clad with a double-skin façade that follows the geometry of tilted cylinders, in order to standardize the curtain wall panels and reduce costs. The lobby is enclosed by a warped glass wall that creatively solves the challenges posed by its complex 3D geometry by using cold-bent glass and hybrid glass-and-steel structural fins.
Load-Bearing Capacity of Thin Film Photovoltaic Modules
Authors: Schneider Jens  , Kuntsche Johannes  , Kleuderlein Jonas
Published: February 2025

The increasing use of thin film photovoltaic modules and the increasing occurrence of damages raise the question about a sufficient safety level for the glass-glass-modules used at present. This paper compares the experimental determination of the load-bearing capacity used in the solar industry according to IEC 61646 and a calculative method according to the German structural design standard for glass structures (DIN 18008). Substantial differences in the safety level are pointed out. Moreover, the load case “temperature” can become relevant for the structural design because of the high solar absorption of the modules. This influence is currently not regulated in the standards. For typical installation situations, a calculative consideration of this load case is discussed.
Through-Cracked Tensile Delamination Tests with Photoelastic Measurements
Authors: Ferretti Daniele  , Rossi Marco  , Royer-Carfagni Gianni
Published: February 2025

The critical mechanism in the post-glass-breakage response of laminated glass is delamination of polymeric interlayer from glass shards. To investigate adhesion properties between glass and PVB, “Through-Cracked-Tensile” tests have been performed at room temperature, with different stain rate and polymer thickness. Using photoelastic properties of PVB, the stress has been detected during the test while measuring force-displacement and force-delamination diagrams. Two different failure modes have been recognized, influenced by the presence of friction while relative sliding between the two materials occurs. A steady delamination takes place only when friction is not present; on the other hand, friction can arrest delamination, and the interlayer eventually breaks. Results have been interpreted though a minimal model that predicts the delamination load.
Experimental Investigations on Continuous Glass-GFRP Beams; Preliminary Non-Linear Numerical Modelling
Authors: Valarinho Luís  , Correia João R.  , Branco Fernando  , Sena-Cruz José
Published: February 2025

This paper describes results of experimental and numerical investigations about the structural behaviour of composite beams made of annealed glass panes and GFRP pultruded profiles. A brief description of flexural tests previously carried out on simply supported glass and glass-GFRP composite beams is first presented. Then, results of flexural tests on two-span glass-GFRP composite beams, bonded with three different structural adhesives, are described in detail. Finally, a preliminary numerical study of the glass-GFRP composite simply supported beams is presented. In this study, two-dimensional finite element models were developed in order to simulate and analyse the serviceability and post-cracking behaviour of those beams. Experimental and numerical results presented in this paper prove the advantages and technical viability of glass-GFRP composite beams.
Further Research About the Short and Long-Term Breakage Behaviour of Hybrid Glass-Steel Elements
Authors: Weller Bernhard  , Krampe Philipp  , Retsch Stefanie
Published: February 2025

Laminated glass-steel-beams bonded together with a transparent acrylate adhesive can improve the post-breakage performance. One result of the short-term tests is the higher capacity of the hybrid beams compared to conventional laminated glass. Another conclusion is the post-breakage behaviour of the beams, which highly depends on the thermal pre-stressing used glazing. Annealed glass beams are able to bear higher loads after failure while fully tempered glass shows almost no post-breakage behaviour. Much more surprising are the results of the long-term research investigation. Several hours after the breaking of the glass the deformation of the bonding joint was observed. This behaviour led to independent deformations of the single materials glass and steel of the hybrid beam. Their deformation curve is directly influenced by the load bearing capacity of the component materials. The compensating function of the acrylate adhesion will be given in the paper.
Cold-Bent Single Curved Glass; Opportunities and Challenges in Freeform Facades
Authors: Feijen Mark  , Vrouwe Ivo  , Thun Peter
Published: February 2025

The use of freeform geometry in architectural design necessitates a progressive building industry to be materialized. Great progress has been made in shaping materials into double curved surfaces by moulds and milling techniques. However, using these techniques in a material and energy efficient way proves to be a great challenge. Current solutions often result in less affordable techniques. In this paper the opportunities and challenges of cold-bent single curved glass are discussed. In comparison to most design industries, the architectural industry often constructs large surfaces with relatively little curvature. By subdividing these double-curved surfaces into single-curved parts, the initial design is translated into a specific material efficient geometry. After translation, the geometry can be materialized in Cold-Bent Glass. In most cases these techniques can compete well with preformed glass solutions.
Quality Control of Bent Heat Strengthened and Fully Tempered Glass by the Application of Photoelasticity
Authors: Feldmann Markus  , Di Biase Pietro  , Kasper Ruth
Published: February 2025

Irregularities of the prestress distribution have been detected in some products of bent heat strengthened resp. fully tempered glass [1]. However, until now, a basis for the interpretation of these irregularities has not been found. A reason for this may be the lack of knowledge on the correlation of the visualized colours from polarization filters and the state of stress. Therefore, the product quality of bent glass was investigated by visualizing the distribution of the differences of orthogonal stress integrals. This combined with the visualized colours gives a deeper insight in the resulting fracture patterns of glass. The results shall also serve for a future online quality monitoring system.
Main Achievements of VITAL (enVIronmenTALly Friendly Aero Engine)
Authors: Goutines Marius
Published: February 2025

VITAL programme started in January 2005 and was completed in December 2010. It was devoted to investigation of architectures and technologies able to reduce aero-engines environment impacts. The two main specific objectives of VITAL were a reduction of community noise by 6 EPNdB per operation and a reduction of CO2 emission by 6% (i.e. –6% fuel burn). This paper presents a brief description of the main achievements in each investigated turbofan domain.
Contract-Based Air Transportation System (CATS) – A New Way of Managing 4D Trajectories
Authors: Rihacek Christoph
Published: February 2025

Contract-of-Objectives (CoO) is a specific tool in the context of trajectory-based Air Traffic Management (ATM), considering mutually agreed objectives between Air Traffic Control (ATC) entities, airlines and airports. This paper provides an overview of the CoO assessment performed during the CATS project and introduces the three Human-in-the-Loop (HIL) experiments carried-out in order to evaluate the concept of operations. Sufficient data were collected during the three experiments and analyzed in terms of system performance (i.e. safety, efficiency, and capacity) and human performance (i.e. workload, situation awareness, and acceptability). Final results show that controllers and pilots tend to accept the concept of operations and they prefer the approach of flying what was “planned, agreed and negotiated” during the planning phase, over the current principle, which is a “first come, first served” approach. Renegotiation of flight trajectories was considered as manageable, even with a traffic load extrapolated to the year 2020, without impact on safety. All actors participating in the validation exercises have recognized that implementation of CoO increases the amount of collaboration between crew and ground, as they share not only the same data, but also the same stable objective during the entire flight, i.e. the objective determined at strategic level through a Collaborative Decision Making process (CDM). Some additional Human Machine Interface (HMI) improvements are needed and also the task of calculating Target Windows (TWs) has to be refined. Airport and airline operators, as well as the network manager considered the renegotiation process to be feasible and acceptable. They acknowledge the principle of sharing the operational data of other actors as a great improvement in the way the decisions are made and validated.
A Technical Vision of Sustainable Commercial Air Transportation in 2030
Authors: Epstein Alan H.
Published: February 2025

In the last few years, concern for climate change coupled with high and uncertain prices for petroleum based fuels has stimulated aerospace R&D around the world. Even without this recent stimulus, over the past 50 years, the fuel per seat km burned by a commercial jet has dropped by over 80%, at compounded rate of about 2% per year since 1970. This tremendous progress has been made without deviating from the fundamental architecture of the Boeing 707, introduced into service in the late 1950s. While modern aircraft are much more refined in their aerodynamics, structures and materials, subsystems and engines, they retain the same tube-fuselage, low-swept wing, and underwing-pylon engine mount configuration introduced over 50 years ago. European ACARE and NASA N+2 goal setters concurred that this rate of fuel burn improvement can continue at least through the end of the next decade if R&D resources are available. Significant gains in noise and NOX emissions are desired as well. Pratt & Whitney has worked on advanced engines architecture and in conjunction with the Massachusetts Institute of Technology and Aurora Flight Science has examined a wide range of options including aircraft designs, engine designs, enabling technologies, and fuels as part of the NASA N+2 studies [1]. The studies included engine technology, aircraft architectures, and aviation fuels.
A DSS for Strategic Management Based on the Balanced Scorecard Model
Authors: Gomes Luís  , Respício Ana
Published: February 2025

This paper focuses on the adoption of the Balanced Scorecard model [1] for strategic management by a Portuguese insurance company and presents the Decision Support System (DSS) that has been conceived and developed to embody this adoption. A special emphasis is given to the definition of a strategy, the selection of the strategic measures to analyse and monitor and to the selection of initiatives taken to operationalize the identified strategy. The DSS was designed in close interaction with senior executives and was conceived aiming at enabling the company to more effectively analyse and control indicators relevant for its strategic decisions. The achievements resulting from the implementation of the system are presented and reveal that the BSC integrated with a DSS can be an effective strategic management tool for an SME.
Toward a Commonsense Theory of Microsociology: Interpersonal Relationships
Authors: Hobbs Jerry R.  , Sagae Alicia  , Wertheim Suzanne
Published: February 2025

We are developing an ontology of microsocial concepts for use in an instructional system for teaching cross-cultural communication. We report here on that part of the ontology relating to interpersonal relationships. We first explicate the key concepts of commitment, shared plans, and good will. Then in terms of these we present a formal account of simple exchanges, the host-guest relationship, and friendship.
Hybrid Possibilistic Conditioning for Revision under Weighted Inputs
Authors: Benferhat Salem  , da Costa Pereira Célia  , Tettamanzi Andrea G.B.
Published: February 2025

We propose and investigate new operators in the possibilistic belief revision setting, obtained as different combinations of the conditioning operators on models and countermodels, as well as of how weighted inputs are interpreted. We obtain a family of eight operators that essentially obey the basic postulates of revision, with a few slight differences. These operators show an interesting variety of behaviors, making them suitable to representing changes in the beliefs of an agent in different contexts.
A Robust Approach to Addressing Human Adversaries in Security Games
Authors: Pita James  , John Richard  , Maheswaran Rajiv  , Tambe Milind  , Kraus Sarit
Published: February 2025

Game-theoretic approaches have been proposed for addressing the complex problem of assigning limited security resources to protect a critical set of targets. However, many of the standard assumptions fail to address human adversaries who security forces will likely face. To address this challenge, previous research has attempted to integrate models of human decision-making into the game-theoretic algorithms for security settings. The current leading approach, based on experimental evaluation, is derived from a well-founded solution concept known as quantal response and is known as BRQR. One critical difficulty with opponent modeling in general is that, in security domains, information about potential adversaries is often sparse or noisy and furthermore, the games themselves are highly complex and large in scale. Thus, we chose to examine a completely new approach to addressing human adversaries that avoids the complex task of modeling human decision-making. We leverage and modify robust optimization techniques to create a new type of optimization where the defender's loss for a potential deviation by the attacker is bounded by the distance of that deviation from the expected-value-maximizing strategy. To demonstrate the advantages of our approach, we introduce a systematic way to generate meaningful reward structures and compare our approach with BRQR in the most comprehensive investigation to date involving 104 security settings where previous work has tested only up to 10 security settings. Our experimental analysis reveals our approach performing as well as or outperforming BRQR in over 90% of the security settings tested and we demonstrate significant runtime benefits. These results are in favor of utilizing an approach based on robust optimization in these complex domains to avoid the difficulties of opponent modeling.
Axiomatizing Inconsistency Metrics for Integrity Maintenance
Authors: Decker Hendrik
Published: February 2025

Integrity Maintenance includes integrity checking and repairing. Checking updates for integrity prevents an increase of inconsistency, repairing decreases inconsistency. Both can be supported by inconsistency metrics. We improve their axiomatization, which, so far, has been elusive and inappropriate for databases with non-monotonic negation.
A complex system approach for a reliable Smart Grid modeling
Authors: Petermann Coralie  , Ben Amor Soufian  , Bui Alain
Published: February 2025

In this paper, we provide a multi-agent based model for an efficient and reliable Smart Grid simulation. Our model is based on appropriate mathematical theories to get an efficient modeling of complex systems. We specifically focus on Smart Grid, which is a typical complex system due to the heterogeneity of actors, economic issues and material aspects. It takes into account the heterogeneity of components, links them with a generalized proximity concept, and guarantee an optimal smooth functioning of the global system.
Ontology modeling for intelligence: the ONTO-CIF model
Authors: Dragos Valentina
Published: February 2025

In highly dynamic and heterogeneous environments, such as coalition missions or joint operations can be, providing commanders with decision making support requires a through understanding of processes involved and the development of underlying knowledge models upon which reasoning mechanisms can be based. This paper presents the construction of ONTO-CIF, a formal ontology created to support intelligence activities. ONTO-CIF is a core ontology, developed by following a methodology based on textual documents, which allows us to accomplish a satisfactory accuracy level in terms of domain coverage. The paper also illustrates several scenarios using ONTO-CIF to support intelligence analysis, a central task of military domain.
Discovering shoppers’ journey in retail environment by using RFID
Authors: Vukovic Marin  , Lovrek Ignac  , Kraljevic Hrvoje
Published: February 2025

Understanding the customers’ needs is becoming more and more important in retail as it may provide valuable information that can be used to improve customer’s shopping experience and product sales. Knowing about customers’ behaviour within the store can provide information for improving customer relationship management and including real-time capabilities. This paper presents an experimental system for shopping path tracking and analysis that uses RFID for positioning shopping baskets. The collected data is used for determining customer presence and movement through a store, as well as time spent in specific store segments. The field trial of the proposed system in a real store is presented.
The Turkish Aviation System and the Strategy of Turkish Airlines
Authors: den Hartigh Erik  , Küçükönal Hatice  , Verheij Bas
Published: February 2025

We sketch the history and development of the Turkish aviation system and we analyze the position and strategy of Turkish Airlines as the major player in this system. Turkish international aviation was liberalized in 1983, but domestic aviation was only liberalized in 2003. Combined with Turkey's economic development, this opened up the aviation system and ensured its growth. Turkish Airlines was the first company in the system, established 1933. It is still the dominant player, shaping the system as well as profiting from its growth. We provide a strategic analysis of Turkish airlines based on data from 2001 to 2011. We analyze the qualitative development of its business model, the quantitative development of its financial value creation, and the (in)consistencies between these.
Safety Management as an Aspect of Business Management
Authors: Dijkstra A.
Published: February 2025

Flight safety is a critical success factor for an airline. The whole airline organization plays an important role to achieve an acceptable level of safety but it has not yet been managed across all organizational levels as a business integrated system. Regulations issued by international authorities focus mainly on what kind of safety management activities should be executed. Safety science provides requirements for how the SMS should be structured. In this research I develop a model taking into account the what and the how to assist where to find safety topics. I will propose an airline safety management system which could become part of the airline organization business system. Both systems will be modeled using the same concept. One essential requirement is to translate operational safety into meaningful variables for each level of the organization. The Viable System Model and its foundation on cybernetics laws and principles will be used to describe an airlines control structure for managing the essential variable of safety. Every process needs to be managed to ensure a balance between efficiency and effectiveness. Cybernetics and the VSM in particular will be used to create in software an explicit organizational model including safety management to manage business concerns in the context of value production, under the increasing pressure of complexity and economy.
How to improve operational availability and cost effectiveness using a pragmatic RAMS Value Driven Design effort
Authors: van Baaren Ron J.  , Curran Ricky
Published: February 2025

This paper gives insight into the development of a strategic value based decision model (SMARD) for the effective implementation of Reliability, Availability, Maintainability and Supportability (RAMS) in the design process of complex technical systems. This paper shows the application of this model to the military aircraft domain to improve operational availability and cost effectiveness. Two individual case studies performed in a military helicopter development program are described, emphasizing the lessons learned, best practices and improvement areas. These cases prove that the traditional Integrated Logistic Support approach towards the integration of RAMS in design and development of military systems has not been effective. Furthermore conclusions are drawn related to the further development and application of the RAMS Driven Design Approach in other industries.
Validating Value-Driven Design
Authors: Collopy Paul D.  , Poleacovschi Cristina
Published: February 2025

Value-Driven Design is a systems engineering process intended to improve the outcomes of large engineering systems development programs, which typically involve thousands of engineers, billions of euros of cost, and many years to complete. Does this, or does any comparable systems engineering methodology actually work? With such programs, it is impossible to conduct meaningful clinical trials. Also, the programs are sufficiently complex that it is impossible to observe much of what goes on. The Center for System Studies is developing a laboratory in simulation to examine systems engineering processes operating within simulated development programs. This paper reports on progress constructing multi-scaled simulations for this purpose. It also conveys the results of a prototype simulation project.
NFF – Who is to be Blamed? Unravelling the Mysteries of NFF
Authors: Meyer Bernhard
Published: February 2025

This paper outlines the rationale, contents, and application of the ARINC 672 Guideline. It follows an integrated approach towards understanding the issues at stake when considering the No Fault Found (NFF) phenomenon, to purposefully work towards an NFF-reduction solution. And for this purpose the outline is structured along the following topics, i.e.: Introducing the situational context, Presenting some underlying principles, Describing an integrated process, Concluding with an appraisal. The objective is to highlight the fundamental “back to the basics” approach followed for ARINC 672 thus qualifying it as a suitable baseline treatment of the NFF-topic and document on which any future refinements can be based. It also outlines the application of the guideline which is sufficiently general for an appropriate tailoring and customisation in the aviation and for that matter also many other industry branches.
Cost-Benefit Evaluation of Aircraft Maintenance Base-Check Downtime and Cost
Authors: Schilling Thomas  , Hölzel Nico B.  , Langhans Stephan
Published: February 2025

This paper analyzes the impact of varying downtime and cost of base maintenance checks for aircraft and gives an economic cost-benefit assessment. The reduction of downtimes for scheduled base maintenance checks is complex in terms of technical and logistical aspects. Therefore, the net benefit of such efforts is evaluated to optimize maintenance cost and aircraft availability from an aircraft operator point of view. For this purpose, the cost-benefit model AirTOBS (Aircraft Technology & Operations Benchmark System) is set up. The model is able to capture all economically relevant impacts on aircraft operations and maintenance over the life cycle. AirTOBS follows a discrete event simulation approach for aircraft operation and maintenance to capture time effects. An operator life cycle cost-benefit analysis accounts for costs and benefits. A use case of an Airbus A320 similar aircraft is conducted to show the potential of maintenance downtime reductions in terms of time and cost aspects. It is shown that the potential of a C-Check downtime reduction by 12.5% is worth a C-check cost increase of 10%, depending on various operational and maintenance aspects. Further, a set of ISO curves for constant net-present values of an airline is provided to show the cost increase potential of decreasing C-check downtimes.
Modification and Certification of Research Aircraft
Authors: Kickert Reiner
Published: February 2025

In this paper strategies for substantiation of airworthiness for modified type certificated standard aircraft are discussed. Modifications shown include complex external structures like a flying wind tunnel, ring antennas, wing stores, and nosebooms. An equivalent level of safety compared to the original certification specification is maintained by structural testing and limitations to the aircraft's flight envelope. Hence aircraft modification and certification involves different technical fields; prerequisites for collaboration between specialized Design Organizations are explored.
Analysis of Accident Risk Related Events and the Roles of Agents in Conflict Recognition and Resolution during a Runway Incursion Scenario
Authors: Mogles N.M.  , Stroeve S.H.  , Bakker G.J. (Bert)
Published: February 2025

This paper extends a safety analysis based on a multi-agent dynamic risk model (DRM) of a future mix mode taxiing into position and hold (TIPH) operation. The TIPH operation aims at placing an aircraft on the mixed mode runway, ready for immediate takeoff as soon as takeoff clearance has been issued by the air traffic controller. In the previous safety analysis, accident risk results were obtained by Monte Carlo simulations of a multi-agent DRM for a particular scenario describing the conflict between an aircraft landing and an aircraft lining up while it should not. These risk assessment simulations and results obtained earlier do not provide insight into the underlying conflict detection and conflict recognition events that occur during the simulations. Therefore relevant events were defined and recorded in additional Monte Carlo simulations of the multi-agent DRM in different visibility conditions. An additional aim of the present research is an examination of the capabilities of agents to reduce the accident risk in the operation. This is studied in the DRM by placing agents out of monitoring or control loops in different visibility conditions. The results of the study make clear the extent to which each agent is able to reduce the accident risk and the complementarities between the agents' roles in controlling the accident risk.
The impact of airlines' collaboration in Air Traffic Flow Management
Authors: Castelli Lorenzo  , Corolli Luca  , Lulli Guglielmo
Published: February 2025

Aircraft operators need some flexibility when executing flight operations such as taking off, landing or entering into a sector, because the exact time of these operations is often affected by uncertainty. We express this flexibility in terms of time windows which are periods of time assigned to flights under the agreement that when a flight performs all its operations within the corresponding time windows no downstream delay is caused to any other actor of the air traffic system. If some last minute inconveniences make a flight unable to meet its time windows, some delay may also be caused to other flights. Relying on simulated and real air traffic data of the European airspace, this paper shows that this additional delay can be significantly reduced if there is the opportunity to reallocate unused airport or sector capacity, especially when airlines collaborate by updating and disclosing their expected times of departure, arrival and entry into sectors.
Knowledge Mining of Web Service Usage
Authors: Soininen Jari  , Jaakkola Hannu
Published: February 2025

Website usage continues to increase, while the number of servers increases, their total energy consumption is growing. Meanwhile, server utilization is consistently very low. Servers can be combined to effectively increase the utilization rate and hence the energy consumption even while reducing maintenance costs. This requires, however, that the knowledge of usage of services is updated and the information is sufficient. Usage of services will change as a consequence of users' habits and as a result of internal changes of the service. Therefore, usage of the service has to be capable of being continuously analyzed and to be able to express the result in an easily understandable manner. In the literature, there are several ways to analyze usage of web service. So far, none of these has been found suitable for continuous and automated analysis, in a way that could produce results for programmatic use in the future. We present an automated method for modeling web service usage. The model can help increase knowledge of website usage. As a result, valid actions can be taken in capacity planning and to consequently reduce the energy consumption. At the same time, it will also ensure that service quality remains satisfactory in relation to real demand.
Recent European contributions to ground improvement
Authors: Varaksin S.
Published: February 2025

This panel contribution summarizes the 20thand 21stcentury major advances and contrubtions to the developpement of ground improvement from Europe.