Concept Of Fragility Research Articles

Fragility in Network Systems: An Empirical Investigation

A survey of the relevant literature reveals that a plethora of network analytic facets, such as degree, eigenvalue, density, block, cluster, have been developed and employed to further our understanding of network structures. To extend our understanding of network systems, additional dimensions need to be identified that shed light on the dynamic processes among individual member nodes within network structures. Within the context of network systems, this paper proposes a new concept of fragility. More specifically, it develops and empirically tests a mathematical model of fragility from the standpoint of how ties among network members significantly influence corporate performance, thus uniquely contributing to extant knowledge. Using data drawn from two well-known network organizations, Mazda and Toyota, this research attempts to shed light on the relationship between degree and fragility, to confirm the validity of the new concept as well as enabling a contrast of Mazda and Toyota’s network structures. Based on the findings, the managerial implications are discussed, the study limitations are identified and directions for further research are suggested.

Uremic Toxicity and Bone in CKD.

Patients with chronic kidney disease (CKD), especially those on dialysis treatment, are at high risk of bone fracture. In CKD-mineral and bone disorder (CKD-MBD), secondary hyperparathyroidism in patients with advanced CKD induces bone abnormalities, and skeletal resistance to parathyroid hormone (PTH) starts in the early stages of kidney disease. Uremic toxins such as indoxyl sulfate and p-cresyl sulfate reduce the expression of PTH receptor as well as PTH-induced cyclic adenosine 3',5' monophosphate production in osteoblasts. CKD also impairs bone strength, especially quality. In a rat model, kidney damage reduces the bone-storage modulus and changes the cortical bone chemical composition with or without hyperparathyroidism. The oral charcoal adsorbent AST-120 improves CKD-induced bone abnormalities as blood levels of indoxyl sulfate decrease. Uremic osteoporosis, a new concept of CKD-related bone fragility, is a main cause of CKD-induced bone abnormalities, particularly impaired bone quality. There is limited information about the effect and safety of anti-osteoporotic drugs for patients with CKD, especially those on dialysis, but the use of AST-120 and renin-angiotensin system inhibitors may modulate bone quality and decrease the incidence of fracture. Thus, the management of CKD-MBD plus use of other therapeutic interventions for uremic osteoporosis is necessary to prevent bone fragility in patients with CKD.

FEATURE VECTOR CONSTRUCTION METHOD FOR IRIS RECOGNITION

Abstract. One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.

From failed states to fragile cities: redefining spaces of humanitarian practice

It has become commonplace to claim that cities are becoming conflict zones, or ‘war zones’. This article traces some of the discursive and conceptual shifts that made it possible to define the city as a new frontier for international humanitarian action in states of the Global South. In order to represent cities as humanitarian spaces, concepts of ‘failure’ and ‘fragility’ have been problematised and subjected to reinterpretations that legitimised new strategies applied to the urban realm. I argue that this re-scaling of humanitarian practices enables a de-coupling and inclusion of so called new ‘urban conflicts’ in strategies of global liberal governance. Moving from failed states to fragile cites is a key development to understand changes in the practices that redefine humanitarian spaces today. The definition of urban violence as a new type of conflict informs a new cycle of expansion of the humanitarian order focused on the city. The article analyses the problematisation of concepts of failure and fragility as a decisive move to redefine the boundaries of humanitarian spaces.

Institutional fragility and outward foreign direct investment from China

We develop the concept of institutional fragility to investigate the outward foreign direct investment (OFDI) behavior of firms from emerging economies. When different dimensions of institutions are not progressing at the same pace, internal friction and conflict arise during institutional development. Such fragility could push a firm to escape its home country as a strategic response. Using a sample of 578,360 Chinese firm-year observations over a 10-year period, we find that institutional fragility at the provincial level is associated with increased OFDI decision. This relationship is weaker when firms have high productivity or have been controlled by state with high ownership, stronger when firms have a high level of export network. Overall, our institutional fragility perspective extends and enriches the institution-based view and offers new insights into OFDI behavior.

Viscosity of glass‐forming systems

AbstractAs one of the most important properties of glass‐forming liquids, viscosity has drawn significant attention in both glass manufacturing and fundamental research. We review the recent scientific progress in viscosity of glass‐forming systems, including both the liquid and glassy states. After the Vogel‐Fulcher‐Tammann (VFT) equation was introduced, many more efforts have been made to develop more accurate models to describe the temperature dependence of viscosity. In addition to the VFT equation, we also discuss three other viscosity models, viz., the Adam‐Gibbs, Avramov‐Milchev, and Mauro‐Yue‐Ellison‐Gupta‐Allan models. We compare the four viscosity models in terms of their theoretical underpinnings and ability to fit measured viscosity curves. The concept of fragility and the universality of the high‐temperature viscosity limit are also discussed. Temperature‐dependent constraint theory is introduced in detail as a powerful tool for predicting the composition dependence of viscosity. Some examples of the application of this approach to predict the glass transition temperature and fragility of various glass systems are shown. Topological constraint theory is not only of scientific interest, but also has important industrial applicability. We also discuss the thermal history dependence of viscosity in the glassy state. Some phenomenological models are briefly reviewed, while the main focus is given to the modified Mauro‐Allan‐Potuzak model, which can accurately predict the nonequilibrium viscosity as a function of temperature, thermal history, and composition. The correlation of viscosity with elasticity is described in terms of the shoving model. Some theoretical implications of the various viscosity models are discussed, including the concepts of the Kauzmann paradox and the ideal glass transition. Some of the evidence against the existence of these phenomena are discussed. We also review the link between glass relaxation and viscosity, that is, emphasizing that the viscosity equations presented in this review can also be used to model different types of relaxation effects based on the Maxwell relation.

Excess thermodynamic properties of glassforming liquids: The rational scaling of heat capacities, and the thermodynamic fragility dilemma resolved

With the overall objective of clarifying some perennial issues with the concept of liquid fragility, and with thermodynamic fragility in particular focus, we review the determination of excess thermodynamic properties of liquids as the temperature rises above Tg. We treat the compressibility first, as it is the one most commonly encountered in theory where it may be derived from the radial distribution function (specifically, from its Fourier transform (the structure factor) at zero wave vector), and is known to be proportional to the mean square density fluctuation. We show that the compressibility of glassforming liquids, and also the difference in compressibility between liquid and glass, always decreases as Tg is approached with the exception of a few water-like (anomalous) liquids. Secondly we examine the heat capacity which is favored in the analysis of glassforming liquid behavior. Contrasting with the compressibility, the excess heat capacity (determined by entropy fluctuations), mostly increases as temperature approaches Tg (with the same exceptions). But here we encounter the problem of the appropriate scaling of the measured molar quantity, which plagues comparisons of ∆Cp between different substances. We solve this problem by defining Cp as an entropy derivative and scaling by the absolute excess entropy at Tg - which avoids the need for “beads” or other artificial scaling methods. Finally, we revisit the subject of thermodynamic fragility, which has been discussed before using a related scaling strategy.

Crystallization of Glass: What We Know, What We Need to Know

The relevance of the concepts of fragility and of the glass transition temperature for the understanding of crystal nucleation and growth in glass‐forming liquids is explored. It is shown that classical fragility can be relevant for the understanding of the crystallization behavior only if several severe conditions are fulfilled that are rarely met. By this reason, a new definition of liquid fragility is introduced shown to be able to reflect appropriately the maxima of crystal nucleation, growth, and overall crystallization rates. The origin of the previously reported correlations between glass transition temperatures and intensity of crystallization processes is specified. Further, interpreted in terms of classical nucleation theory, for a variety of oxide glass‐forming liquids, the thermodynamic barrier for homogeneous crystal nucleation exhibits at high undercooling an unusual increase with a decrease in temperature. Such behavior cannot be explained in terms of classical nucleation theory. Different directions of generalization of the classical theory are discussed, which may lead to a resolution of these problems. The realization of such generalization is considered to be a prerequisite for a generally deeper understanding of the complex phenomena occurring in melt crystallization with its rich field of applications.

Systems fragility: The sociology of chaos.

This article examines the concept of community fragility in emergency management from a systems perspective. Using literature that addresses fragility in four areas of complex systems, including ecosystems, social systems, sociotechnical systems, and complex adaptive systems, a theoretical framework focused on the emergency management field is created. These findings illustrate how community fragility factors can be used in the emergency management field to not only improve overall outcomes after disaster but also build less fragile systems and communities in preparation for future disasters.

Revealing the role of molecular rigidity on the fragility evolution of glass-forming liquids.

If quenched fast enough, a liquid is able to avoid crystallization and will remain in a metastable supercooled state down to the glass transition, with an important increase in viscosity upon further cooling. There are important differences in the way liquids relax as they approach the glass transition, rapid or slow variation in dynamic quantities under moderate temperature changes, and a simple means to quantify such variations is provided by the concept of fragility. Here, we report molecular dynamics simulations of a typical network-forming glass, Ge–Se, and find that the relaxation behaviour of the supercooled liquid is strongly correlated to the variation of rigidity with temperature and the spatial distribution of the corresponding topological constraints, which ultimately connect to the fragility minima. This permits extending the fragility concept to aspects of topology/rigidity, and to the degree of homogeneity of the atomic-scale interactions for a variety of structural glasses.

Managing for integration: a longitudinal analysis of management control for sustainability

Based on a longitudinal eight-year study (2006–2014) in a large Italian food co-operative, this paper analyses whether and how the development and the use of sustainability control systems have been able to promote the integration of sustainability within organisational strategy. The co-operative has implemented three main instruments (sustainability report, sustainability annual plan and participatory social plan), which have been able to promote sustainability integration by inducing technical integration and reinforcing the cognitive enablers. However, strong cognitive (and organisational) barriers have gradually stifled the cognitive enablers and have not enabled sustainability to be fully integrated into the organisational strategy. As such, the integration process was marginalised, also due to the negative economic performance of the co-operative. The paper shows that sustainability integration remains a fragile concept even in a co-operative, despite the similarities between co-operative values and the principles of corporate social responsibility. Theoretically, the paper offers empirical evidences concerning management control literature for sustainability.

Institutional fragility and firm characteristics:the internationalization of Chinese SMEs

We use the concept of regulative institutional fragility to investigate the internationalization of Chinese SMEs. Compared to their sizable counterparts, Chinese SMEs are facing a more stringent re...

Managing Disaster Risk: An Integrative Essay About Governance, Capacity, Fragility, and Vulnerability

The concepts of governance, capacity and fragility have been used by researchers, practitioners and donors focused on development in low income countries. All three concepts remain contested; there are neither undisputed meanings nor applications for each of them. Nevertheless, in international development the three concepts are in good currency and they are used to interpret myriad dimensions of development including how disaster risk management is practiced in low income countries. By connecting the three development concepts with a fourth—vulnerability, we provide a more comprehensive understanding of how development interventions, specifically those related to disaster risk management, can be targeted in countries labelled as fragile. This approach is consistent with recent arguments that recommend sector specific and even program specific interventions that may have a higher likelihood of succeeding by iteratively addressing vulnerability in countries with poor governance, fragility and low capacity.

Fragility analysis and estimation of collapse status for transmission tower subjected to wind and rain loads

In this paper, the fragility analysis and concept of critical collapse curve for transmission tower subjected to wind and rain loads are presented to acquire the collapse equivalent basic wind speed and most unfavorable combinations of wind and rain loads corresponding to collapse status. The calculating method for wind and rain loads is simplified and the error analysis is performed to validate its effectiveness. The concept of equivalent basic wind speed is used to conduct the fragility analysis of transmission tower subjected to wind and rain loads which avoid the complex formula of rain load and the choice of different combinations of basic wind speed and rain intensity, and then the concept of critical collapse curve is proposed to evaluate the collapse status of transmission tower. At last the influence of wind attack angle and wind spectrum on the fragility and critical collapse curves is discussed, and results show that the wind attack angle and wind spectrum have a great influence on fragility and critical collapse curves. In this study, it can be seen that the use of equivalent basic wind speed make it possible to conduct the fragility analysis under wind and rain loads and the proposed concept of critical collapse curve is very convenient to evaluate the collapse status for structures subjected to wind and rain loads. In addition, the rain load has a great contribution to the tower collapse and should be paid more attention during severe gales and thunderstorms.

DISAPPEARING SOUNDS: FRAGILITY IN THE MUSIC OF JAKOB ULLMANN

AbstractThe music of Jakob Ullmann (b. 1958) is notable for its protracted structural stasis and delicacy; its fusion of rigorously engineered notational systems, abstract graphical elements and Byzantine iconography; and – above all – its unrelenting quietness. This article offers a rare view into Ullmann's compositional practices, with a specific focus upon the role of fragility in the work. Exploring this concept of fragility as a musical feature, this article considers a number of Ullmann's works from the perspectives of the compositions and their scores, the performance and the agency of performers and, finally, how audiences may listen to this fragility. The article concludes with a consideration of the importance of fragility to Ullmann's oeuvre, and of how it might help us to further understand his music.

Dynamic mechanical properties and the dynamic fragility concept applied to vegetal fiber on vegetal composite materials

The dynamic fragility concept has been performed on kenaf and jute composites containing different reinforcement contents. Based on the average relaxation times, we have determined, as a function of the type of reinforcement and fiber content, the dynamic fragility concept of composites manufactured by resin transfer molding. It was constated that for these polymeric composite materials, the glass transition temperature is not a so significant feature to evaluate the characteristic parameters of the Williams–Landel–Ferry and Vogel–Fulcher–Tamman equations. The reason is that for up to 30% reinforcement volume, the glass transition values maintain similar values for these composites, whereas mechanical and dynamical mechanical properties shown an increase in the properties by fiber incorporation. Also, the activation energy as the structural relaxation energy would give a more realistic approach of the results found, following the McKenna supposition.

Crystallization in glass-forming liquids: Effects of fragility and glass transition temperature

The relevance of the concepts of fragility, m, of the liquid and of the reduced glass transition temperature, Tg/Tm (Tg: glass-transition temperature, Tm: melting or liquidus temperature) for the understanding of crystal nucleation and growth in glass-forming liquids is explored. Based on the analysis of crystallization processes in glass-forming melts, it is shown that classical fragility can be relevant for the understanding of the crystallization behavior only if several severe conditions are fulfilled that are rarely met. By this reason, a new definition of liquid fragility is introduced. This new definition does not involve the commonly utilized temperature ratio Tg/T (T: actual temperature). Instead, we employ the reduced variable Tm/T and do not restrict the computation of m to the glass transition temperature, Tg, as in the standard approach. Moreover, we specify the fragility index by computing it for the temperature appropriate for the particular kinetic process being analyzed. With this modified definition of fragility applied to both the diffusion coefficient controlling crystallization and viscosity, fragility becomes one of the main factors determining the temperatures and magnitudes of the maxima of nucleation, growth, and overall crystallization rates. In addition, the origin of the previously reported correlations between reduced glass transition temperatures and intensity of crystallization processes is specified.

Complexity, flow, and antifragile healthcare systems: implications for nurse executives.

As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on the application of management strategies in health systems. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. In this article, I further discuss the concept of fragility, its impact on system behavior, and ways to reduce it.

Combining Flash DSC, DSC and broadband dielectric spectroscopy to determine fragility

New experimental results focused on Flash DSC, DSC and broadband dielectric spectroscopy investigations are reported in this work. The fictive temperatures and fragility indexes are estimated from Flash DSC experiments and compared to values obtained from classical DSC. The consistency of the Tool–Narayanaswamy–Moynihan model and fragility concept is then investigated over a large range of cooling rates. Indeed, the Flash DSC allows exploring thermal properties of materials over a continuous and broad range of heating and cooling rates, complementary to rates usually available with DSC. The reliability of investigations is also demonstrated by comparing results obtained from two model amorphous polymeric systems: polystyrene and poly(ethylene terephthalate)-glycol. The temperature dependence of the cooling rate obtained by Flash DSC and DSC is also compared to the temperature dependence of the relaxation times obtained from broadband dielectric spectroscopy, experiment considered as the reference concerning the fragility measurements. The comparison of these two dependencies implies a better understanding about the origin of the temperature dependence of the cooling rate.

The Belief Illusion

I offer a new argument for the elimination of ‘beliefs’ from cognitive science based on Wimsatt’s ([1981]) concept of robustness and a related concept of fragility. Theoretical entities are robust if multiple independent means of measurement produce invariant results in detecting them. Theoretical entities are fragile when multiple independent means of detecting them produce highly variant results. I argue that sufficiently fragile theoretical entities do not exist. Recent studies in psychology show radical variance between what self-report and non-verbal behaviour indicate about participants’ beliefs. This is evidence that ‘belief’ is fragile, and is thus a strong candidate for elimination.