Firms as adaptive organizations : the case of Australian trading banks

The conventional accounting notion of ‘going concern’ — that a firm will continue its business operations in the same manner indefinitely — has underpinned accounting practice for over one hundred years. This idea has provided a rationale for spreading costs over accounting periods and for deferring costs as assets in balance sheets. An alternative idea that is widely regarded as reliable in the literatures of economics and deliberate action is that firms continually adapt to changes in market and economic conditions. That is economic behaviour. The implications of that view of a firm for accounting have been systematically explored by Chambers (1966). While not examining those particular implications, many other accounting theorists have been critical of the conventional accounting idea of 'going concern' and of its impact on accounting practice. The two notions of ‘going concern’ - as static or adaptive enterprises - are examined by referring to the business operations of the four major Australian trading banks over the period 1983-1991. Banks were selected because they are commonly thought to be particularly ‘conservative’ organizations. The period 1983—1991 was chosen because it covers the era of deregulation of the Australian financial system. The evidence adduced by this study indicates that the Australian trading banks have continually adapted their organizational structures and business operations in the light of changes in technology, markets for financial services, government policies and domestic and global economic conditions. Illustrations of adaptive behaviour by banks ate drawn from their normal operating procedures such as the provision of products and services, loan services, acquisitions, sale of property, non-core banking operations and international banking. It is argued on analytical grounds that the cost basis of accounting does not yield financial statements that provide factual and up-to-date information about the financial capacity of firms to pay their debts and to continue trading generally; that is, to be going concerns. At any time, those financial capacities are determined by the amount of money commanded by a firm, including the money's worth of its assets, and by its level of debt. It is concluded on empirical grounds that the Australian trading banks, at least, are adaptive entities.

A microscopic competition model and its dynamics analysis on network attacks

Modeling network traffic has been a critical task in the development of Internet. Attacks and defense are prevalent in the current Internet. Traditional network models such as Poisson-related models do not consider the competition behaviors between the attack and defense parties. In this paper, we present a microscopic competition model to analyze the dynamics among the nodes, benign or malicious, connected to a router, which compete for the bandwidth. The dynamics analysis demonstrates that the model can well describe the competition behavior among normal users and attackers. Based on this model, an anomaly attack detection method is presented. The method is based on the adaptive resonance theory, which is used to learn the model by normal traffic data. The evaluation shows that it can effectively detect the network attacks.

Adaptive patch size determination for patch-based image completion

Patch-based image completion proceeds by iteratively filling the target (unknown) region by the best matching patches in the source image. In most existing such algorithms, the size of the patches is either fixed and specified by a default number or simply chosen to be inversely proportional to the spatial frequency. However, it is noted that the patch size affects how well the filled patch captures the local characteristics of the source image and thus the final completion accuracy. Thus in this paper we propose a new method to compute appropriate patch sizes for image completion to improve its performance. In particular, we formulate the patch size determination as an optimization problem that minimizes an objective function involving image gradients and distinct and homogenous features. Experimental results show that our method can provide a significant enhancement to patch-based image completion algorithms.

Developing an empirical algorithm for protecting text-based CAPTCHAs against segmentation attacks

In this paper, we aim to provide an effective and efficient method to generate text-based Captchas which are resilient against segmentation attack. Different to the popular industry practice of using very simple color schemes, we advocate to use multiple colors in our Captchas. We adopt the idea of brush and canvas when coloring our Captchas. Furthermore, we choose to use simple accumulating functions to achieve diffusion on painted colors and DES encryption to achieve a good level of confusion on the brush pattern. To facilitate ordinary users and developers, we propose an empirical algorithm with support of Taguchi method to guarantee the quality of the chosen color schemes. Our proposed methodology has at least three advantages — 1) the settings of color schemes can be fully customized by the user or developer; 2) the quality of selected colors have desirable statistical features that are ensured by Taguchi method; 3) the algorithm can be fully automated into computer programs. Moreover, our included examples and experiments prove the practicality and validity of our algorithm.

Robustness enhancement of quantization based audio watermarking method using adaptive safe-band

This paper presents a novel adaptive safe-band for quantization based audio watermarking methods, aiming to improve robustness. Considerable number of audio watermarking methods have been developed using quantization based techniques. These techniques are generally vulnerable to signal processing attacks. For these conventional quantization based techniques, robustness can be marginally improved by choosing larger step sizes at the cost of significant perceptual quality degradation. We first introduce fixed size safe-band between two quantization steps to improve robustness. This safe-band will act as a buffer to withstand certain types of attacks. Then we further improve the robustness by adaptively changing the size of the safe-band based on the audio signal feature used for watermarking. Compared with conventional quantization based method and the fixed size safe-band based method, the proposed adaptive safe-band based quantization method is more robust to attacks. The effectiveness of the proposed technique is demonstrated by simulation results. © 2014 IEEE.

The adaptive potential of a survival artist: characterization of the in vitro interactions of Toxoplasma gondii tachyzoites with di-cationic compounds in human fibroblast cell cultures

The impact of di-cationic pentamidine-analogues against Toxoplama gondii (Rh- and Me49-background) was investigated. The 72 h-growth assays showed that the arylimidamide DB750 inhibited the proliferation of tachyzoites of T. gondii Rh and T. gondii Me49 with an IC(50) of 0.11 and 0.13 muM, respectively. Pre-incubation of fibroblast monolayers with 1 muM DB750 for 12 h and subsequent culture in the absence of the drug also resulted in a pronounced inhibiton of parasite proliferation. However, upon 5-6 days of drug exposure, T. gondii tachyzoites adapted to the compound and resumed proliferation up to a concentration of 1.2 muM. Out of a set of 32 di-cationic compounds screened for in vitro activity against T. gondii, the arylimidamide DB745, exhibiting an IC(50) of 0.03 muM and favourable selective toxicity was chosen for further studies. DB745 also inhibited the proliferation of DB750-adapted T. gondii (IC(50)=0.07 muM). In contrast to DB750, DB745 also had a profound negative impact on extracellular non-adapted T. gondii tachyzoites, but not on DB750-adapted T. gondii. Adaptation of T. gondii to DB745 (up to a concentration of 0.46 muM) was much more difficult to achieve and feasible only over a period of 110 days. In cultures infected with DB750-adapted T. gondii seemingly intact parasites could occasionally be detected by TEM. This illustrates the astonishing capacity of T. gondii tachyzoites to adapt to environmental changes, at least under in vitro conditions, and suggests that DB745 could be an interesting drug candidate for further assessments in appropriate in vivo models.

Low awareness of transient ischemic attacks and risk factors of stroke in a Swiss urban community

BACKGROUND AND PURPOSE: Time delays from stroke onset to arrival at the hospital are the main obstacles for widespread use of thrombolysis. In order to decrease the delays, educational campaigns try to inform the general public how to act optimally in case of stroke. To determine the content of such a campaign, we assessed the stroke knowledge in our population. METHODS: The stroke knowledge was studied by means of a closed-ended questionnaire. 422 randomly chosen inhabitants of Bern, Switzerland, were interviewed. RESULTS: The knowledge of stroke warning signs (WS) was classified as good in 64.7%. A good knowledge of stroke risk factors (RF) was noted in 6.4%. 4.2% knew both the WS and the RF of stroke indicating a very good global knowledge of stroke. Only 8.3% recognized TIA as symptoms of stroke resolving within 24 hours, and only 2.8% identified TIA as a disease requiring immediate medical help. In multivariate analysis being a woman, advancing age, and having an afflicted relative were associated with a good knowledge of WS (p = 0.048, p < 0.001 and p = 0.043). Good knowledge of RF was related to university education (p < 0.001). The good knowledge of TIA did not depend on age, sex, level of education or having an afflicted relative. CONCLUSIONS: The study brings to light relevant deficits of stroke knowledge in our population. A small number of participants could recognize TIA as stroke related symptoms resolving completely within 24 hours. Only a third of the surveyed persons would seek immediate medical help in case of TIA. The information obtained will be used in the development of future educational campaigns.

Adaptive sensing for target tracking applications

In a statistical inference scenario, the estimation of target signal or its parameters is done by processing data from informative measurements. The estimation performance can be enhanced if we choose the measurements based on some criteria that help to direct our sensing resources such that the measurements are more informative about the parameter we intend to estimate. While taking multiple measurements, the measurements can be chosen online so that more information could be extracted from the data in each measurement process. This approach fits well in Bayesian inference model often used to produce successive posterior distributions of the associated parameter. We explore the sensor array processing scenario for adaptive sensing of a target parameter. The measurement choice is described by a measurement matrix that multiplies the data vector normally associated with the array signal processing. The adaptive sensing of both static and dynamic system models is done by the online selection of proper measurement matrix over time. For the dynamic system model, the target is assumed to move with some distribution and the prior distribution at each time step is changed. The information gained through adaptive sensing of the moving target is lost due to the relative shift of the target. The adaptive sensing paradigm has many similarities with compressive sensing. We have attempted to reconcile the two approaches by modifying the observation model of adaptive sensing to match the compressive sensing model for the estimation of a sparse vector.

Efficient adaptive methods based on adjoint equations and truncation error estimation for unstructured grids

El propósito de esta tesis es la implementación de métodos eficientes de adaptación de mallas basados en ecuaciones adjuntas en el marco de discretizaciones de volúmenes finitos para mallas no estructuradas. La metodología basada en ecuaciones adjuntas optimiza la malla refinándola adecuadamente con el objetivo de mejorar la precisión de cálculo de un funcional de salida dado. El funcional suele ser una magnitud escalar de interés ingenieril obtenida por post-proceso de la solución, como por ejemplo, la resistencia o la sustentación aerodinámica. Usualmente, el método de adaptación adjunta está basado en una estimación a posteriori del error del funcional de salida mediante un promediado del residuo numérico con las variables adjuntas, “Dual Weighted Residual method” (DWR). Estas variables se obtienen de la solución del problema adjunto para el funcional seleccionado. El procedimiento habitual para introducir este método en códigos basados en discretizaciones de volúmenes finitos involucra la utilización de una malla auxiliar embebida obtenida por refinamiento uniforme de la malla inicial. El uso de esta malla implica un aumento significativo de los recursos computacionales (por ejemplo, en casos 3D el aumento de memoria requerida respecto a la que necesita el problema fluido inicial puede llegar a ser de un orden de magnitud). En esta tesis se propone un método alternativo basado en reformular la estimación del error del funcional en una malla auxiliar más basta y utilizar una técnica de estimación del error de truncación, denominada _ -estimation, para estimar los residuos que intervienen en el método DWR. Utilizando esta estimación del error se diseña un algoritmo de adaptación de mallas que conserva los ingredientes básicos de la adaptación adjunta estándar pero con un coste computacional asociado sensiblemente menor. La metodología de adaptación adjunta estándar y la propuesta en la tesis han sido introducidas en un código de volúmenes finitos utilizado habitualmente en la industria aeronáutica Europea. Se ha investigado la influencia de distintos parámetros numéricos que intervienen en el algoritmo. Finalmente, el método propuesto se compara con otras metodologías de adaptación de mallas y su eficiencia computacional se demuestra en una serie de casos representativos de interés aeronáutico. ABSTRACT The purpose of this thesis is the implementation of efficient grid adaptation methods based on the adjoint equations within the framework of finite volume methods (FVM) for unstructured grid solvers. The adjoint-based methodology aims at adapting grids to improve the accuracy of a functional output of interest, as for example, the aerodynamic drag or lift. The adjoint methodology is based on the a posteriori functional error estimation using the adjoint/dual-weighted residual method (DWR). In this method the error in a functional output can be directly related to local residual errors of the primal solution through the adjoint variables. These variables are obtained by solving the corresponding adjoint problem for the chosen functional. The common approach to introduce the DWR method within the FVM framework involves the use of an auxiliary embedded grid. The storage of this mesh demands high computational resources, i.e. over one order of magnitude increase in memory relative to the initial problem for 3D cases. In this thesis, an alternative methodology for adapting the grid is proposed. Specifically, the DWR approach for error estimation is re-formulated on a coarser mesh level using the _ -estimation method to approximate the truncation error. Then, an output-based adaptive algorithm is designed in such way that the basic ingredients of the standard adjoint method are retained but the computational cost is significantly reduced. The standard and the new proposed adjoint-based adaptive methodologies have been incorporated into a flow solver commonly used in the EU aeronautical industry. The influence of different numerical settings has been investigated. The proposed method has been compared against different grid adaptation approaches and the computational efficiency of the new method has been demonstrated on some representative aeronautical test cases.

Assessing the impact of adaptive accessibility on the optimal transport policy implementation by using an integrated land-use/transport model for Madrid

Accessibility is an essential concept widely used to evaluate the impact of land-use and transport strategies in transport and urban planning. Accessibility is typically evaluated by using a transport model or a land-use model independently or successively without a feedback loop, thus neglecting the interaction effects between the two systems and the induced competition effects among opportunities due to accessibility improvements. More than a mere methodological curiosity, failure to account for land- use/transport interactions and the competition effect may result in large underestimation of the policy effects. With the recent development of land-use and transport interaction (LUTI) models, there is a growing interest in using these models to adequately measure accessibility and evaluate its impact. The current study joins this research stream by embedding an accessibility measure in a LUTI model with two main aims. The first aim is to account for adaptive accessibility, namely the adjustment of the potential accessibility due to the effect of competition among opportunities (e.g., workplaces) as a result of improved accessibility. LUTI models are particularly suitable for assessing adaptive accessibility because the competition factor is a function of the number of jobs, which is related to land-use attractiveness and the number of workers which is related, among other factors, to the transport demand. The second aim is to identify the optimal implementation scenario of policy measures on the basis of the potential and adaptive accessibility and analyse the results in terms of social welfare and accessibility. The metropolitan area of Madrid is used as a case-study and two transport policy instruments, namely a cordon toll and bus frequency increase, have been chosen for the simulation study in order to present the usefulness of the approach to urban planners and policy makers. The MARS model (Metropolitan Activity Relocation Simulator) calibrated for Madrid was employed as the analysis tool. The impact of accessibility is embedded in the model through a social welfare function that includes not only costs and benefits to both road users and transport operators, but also costs and benefits for the government and society in general (external costs). An optimisation procedure is performed by the MARS model for maximizing the value of objective function in order to find the best (optimal) policy imp lementations intensity (i.e., price, frequency). Last, the two policy strategies are evaluated in terms of their accessibility. Results show that the accessibility with competition factor influences the optimal policy implementation level and also generates different results in terms of social welfare. In addition, mapping the difference between the potential and the adaptive accessibility indicators shows that the main changes occur in areas where there is a strong competition among land-use opportunities.

Self-explanation in adaptive systems

The behaviour of self adaptive systems can be emergent. The difficulty in predicting the system's behaviour means that there is scope for the system to surprise its customers and its developers. Because its behaviour is emergent, a self-adaptive system needs to garner confidence in its customers and it needs to resolve any surprise on the part of the developer during testing and mainteinance. We believe that these two functions can only be achieved if a self-adaptive system is also capable of self-explanation. We argue a self-adaptive system's behaviour needs to be explained in terms of satisfaction of its requirements. Since self-adaptive system requirements may themselves be emergent, a means needs to be found to explain the current behaviour of the system and the reasons that brought that behaviour about. We propose the use of goal-based models during runtime to offer self-explanation of how a system is meeting its requirements, and why the means of meeting these were chosen. We discuss the results of early experiments in self-explanation, and set out future work. © 2012 C.E.S.A.M.E.S.

Analysis of Information Security of Objects under Attacks and Processed by Methods of Compression

In this paper a methodology for evaluation of information security of objects under attacks, processed by methods of compression, is represented. Two basic parameters for evaluation of information security of objects – TIME and SIZE – are chosen and the characteristics, which reflect on their evaluation, are analyzed and estimated. A co-efficient of information security of object is proposed as a mean of the coefficients of the parameter TIME and SIZE. From the simulation experiments which were carried out methods with the highest co-efficient of information security had been determined. Assessments and conclusions for future investigations are proposed.

Complex Adaptive On-line Learning System “Theory of Automatic Control"

The controlled from distance teaching (DT) in the system of technical education has a row of features: complication of informative content, necessity of development of simulation models and trainers for conducting of practical and laboratory employments, conducting of knowledge diagnostics on the basis of mathematical-based algorithms, organization of execution collective projects of the applied setting. For development of the process of teaching bases of fundamental discipline control system Theory of automatic control (TAC) the combined approach of optimum combination of existent programmatic instruments of support was chosen DT and own developments. The system DT TAC included: controlled from distance course (DC) of TAC, site of virtual laboratory practical works in LAB.TAC and students knowledge remote diagnostic system d-tester.

Adaptív döntéshozatal a beszállítóválasztás példáján (Adaptive decision-making on example of the supplier selection)

Ez a tanulmány a projektvezetési szakirodalomban kialakult ismeretanyagot szem előtt tartva (noha tételesen nem hivatkozva arra) tárja fel azt a sajátos és tipikusnak nevezhető kontextust, amelyben a projektalapú szervezetek projektmarketing tevékenysége megnyilvánul. A tanulmány célja tehát nem magának a projektmarketingnek a kérdéskörére irányul, hanem elsősorban annak projektspecifikus kontextusára. Jellegét illetően a tanulmány spekulatív jellegű, vagyis lényegét tekintve nem empirikus kutatási eredményekből levont következtetésekre épül. _____ The author analyses the cognitive level of individual decisions by placing the adaptive decision-maker in the centre of interest. The main question is how do adaptive processes evolve and what factors determine the adaptive mechanism. The author builds on his own qualitative study conducted with the Grounded Theory Methodology in the SME sector. The supplier selection decision is chosen from the wide range of business decisions. From the research results the two elements of the adaptive mechanism – the metastructure and the attitude set –, the process of their evolution and the factors determining this process are presented. The findings here are a middle-range theory, which can be elaborated further, but they provide some interesting insights already.

Data-Adaptive Modeling using Convex Regression

Thesis (Ph.D.)--University of Washington, 2016-08