A novel dual complementary output optical fiber transversal filter for DWDM applications

A novel dual complementary output optical fiber transversal filter is realized for DWDM applications. Stable, simultaneous complementary filter responses with flattened passbands and large sidelobe suppressions are achieved with a single-line cascaded Hi-Bi fiber structure.

An artificial neural network stratifies the risks of reintervention and mortality after endovascular aneurysm repair:a retrospective observational study

Background Lifelong surveillance after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is considered mandatory to detect potentially life-threatening endograft complications. A minority of patients require reintervention but cannot be predictively identified by existing methods. This study aimed to improve the prediction of endograft complications and mortality, through the application of machine-learning techniques. Methods Patients undergoing EVAR at 2 centres were studied from 2004-2010. Pre-operative aneurysm morphology was quantified and endograft complications were recorded up to 5 years following surgery. An artificial neural networks (ANN) approach was used to predict whether patients would be at low- or high-risk of endograft complications (aortic/limb) or mortality. Centre 1 data were used for training and centre 2 data for validation. ANN performance was assessed by Kaplan-Meier analysis to compare the incidence of aortic complications, limb complications, and mortality; in patients predicted to be low-risk, versus those predicted to be high-risk. Results 761 patients aged 75 +/- 7 years underwent EVAR. Mean follow-up was 36+/- 20 months. An ANN was created from morphological features including angulation/length/areas/diameters/ volume/tortuosity of the aneurysm neck/sac/iliac segments. ANN models predicted endograft complications and mortality with excellent discrimination between a low-risk and high-risk group. In external validation, the 5-year rates of freedom from aortic complications, limb complications and mortality were 95.9% vs 67.9%; 99.3% vs 92.0%; and 87.9% vs 79.3% respectively (p0.001) Conclusion This study presents ANN models that stratify the 5-year risk of endograft complications or mortality using routinely available pre-operative data.

Nationalism and globalisation:conflicting or complementary?

Nationalism and globalisation are two central phenomena of the modern world, that have both shaped and been shaped by each other, yet few connections have been made systematically between the two. This book brings together leading international scholars to examine the effect of globalisation on nationalism, and how the persistence of the nation affects globalisation. With a range of case studies from Europe, the US and Asia, the authors focus on the interaction between globalisation, national identity, national sovereignty, state-formation and the economy. ◦ Part one provides theoretical reflections on the flexibility and plasticity of the terms nationalism and globalisation focusing on the ways in which nationalism has shaped and has been shaped by globalising forces. ◦ Part two examines the relationship between nationalism and globalisation in different historical eras and different regions, questioning established approaches. ◦ Part three focuses on contemporary issues including the economic crisis, labour migration and citizenship and the theme of global culture. The result is a highly topical account that considers the conceptual landscape of Nationalism and Globalisation. With an interdisciplinary approach, Nationalism and Globalisation will be of interest to students and scholars of political science, sociology, history, economics and international relations.

Internet Social Networks – Benefits and Risks

Доклад, поместен в сборника на Националната конференция "Образованието в информационното общество", Пловдив, май, 2012 г.

Bioactive sol-gel glasses at the atomic scale:the complementary use of advanced probe and computer modeling methods

Sol-gel-synthesized bioactive glasses may be formed via a hydrolysis condensation reaction, silica being introduced in the form of tetraethyl orthosilicate (TEOS), and calcium is typically added in the form of calcium nitrate. The synthesis reaction proceeds in an aqueous environment; the resultant gel is dried, before stabilization by heat treatment. These materials, being amorphous, are complex at the level of their atomic-scale structure, but their bulk properties may only be properly understood on the basis of that structural insight. Thus, a full understanding of their structure-property relationship may only be achieved through the application of a coherent suite of leading-edge experimental probes, coupled with the cogent use of advanced computer simulation methods. Using as an exemplar a calcia-silica sol-gel glass of the kind developed by Larry Hench, in the memory of whom this paper is dedicated, we illustrate the successful use of high-energy X-ray and neutron scattering (diffraction) methods, magic-angle spinning solid-state NMR, and molecular dynamics simulation as components to a powerful methodology for the study of amorphous materials.

Social media in emergency management:Twitter as a tool for communicating risks to the public

One of the main challenges of emergency management lies in communicating risks to the public. On some occasions, risk communicators might seek to increase awareness over emerging risks, while on others the aim might be to avoid escalation of public reactions. Social media accounts offer an opportunity to rapidly distribute critical information and in doing so to mitigate the impact of emergencies by influencing public reactions. This article draws on theories of risk and emergency communication in order to consider the impact of Twitter as a tool for communicating risks to the public. We analyse 10,020 Twitter messages posted by the official accounts of UK local government authorities (councils) in the context of two major emergencies: the heavy snow of December 2010 and the riots of August 2011. Twitter was used in a variety of ways to communicate and manage associated risks including messages to provide official updates, encourage protective behaviour, increase awareness and guide public attention to mitigating actions. We discuss the importance of social media as means of increasing confidence in emergency management institutions.

Interactively developed capabilities:evidence from dyadic servitization relationships

Purpose – The paper challenges the focal firm perspective of much resource/capability research, identifying how a dyadic perspective facilitates identification of capabilities required for servitization. Design/methodology/approach – Exploratory study consisting of seven dyadic relationships in five sectors. Findings – An additional dimension of capabilities should be recognised; whether they are developed independently or interactively (with another actor). The following examples of interactively developed capabilities are identified: knowledge development, where partners interactively communicate to understand capabilities; service enablement, manufacturers work with suppliers and customers to support delivery of new services; service development, partners interact to optimise performance of existing services; risk management, customers work with manufacturers to manage risks of product acquisition/operation. Six propositions were developed to articulate these findings. Research implications/limitations – Interactively developed capabilities are created when two or more actors interact to create value. Interactively developed capabilities do not just reside within one firm and, therefore, cannot be a source of competitive advantage for one firm alone. Many of the capabilities required for servitization are interactive, yet have received little research attention. The study does not provide an exhaustive list of interactively developed capabilities, but demonstrates their existence in manufacturer/supplier and manufacturer/customer dyads. Practical implications – Manufacturers need to understand how to develop capabilities interactively to create competitive advantage and value and identify other actors with whom these capabilities can be developed. Originality/value – Previous research has focused on relational capabilities within a focal firm. This study extends existing theories to include interactively developed capabilities. The paper proposes that interactivity is a key dimension of actors’ complementary capabilities.

Discovering knowledge structures in mind maps of mental health risks

This thesis addressed the problem of risk analysis in mental healthcare, with respect to the GRiST project at Aston University. That project provides a risk-screening tool based on the knowledge of 46 experts, captured as mind maps that describe relationships between risks and patterns of behavioural cues. Mind mapping, though, fails to impose control over content, and is not considered to formally represent knowledge. In contrast, this thesis treated GRiSTs mind maps as a rich knowledge base in need of refinement; that process drew on existing techniques for designing databases and knowledge bases. Identifying well-defined mind map concepts, though, was hindered by spelling mistakes, and by ambiguity and lack of coverage in the tools used for researching words. A novel use of the Edit Distance overcame those problems, by assessing similarities between mind map texts, and between spelling mistakes and suggested corrections. That algorithm further identified stems, the shortest text string found in related word-forms. As opposed to existing approaches’ reliance on built-in linguistic knowledge, this thesis devised a novel, more flexible text-based technique. An additional tool, Correspondence Analysis, found patterns in word usage that allowed machines to determine likely intended meanings for ambiguous words. Correspondence Analysis further produced clusters of related concepts, which in turn drove the automatic generation of novel mind maps. Such maps underpinned adjuncts to the mind mapping software used by GRiST; one such new facility generated novel mind maps, to reflect the collected expert knowledge on any specified concept. Mind maps from GRiST are stored as XML, which suggested storing them in an XML database. In fact, the entire approach here is ”XML-centric”, in that all stages rely on XML as far as possible. A XML-based query language allows user to retrieve information from the mind map knowledge base. The approach, it was concluded, will prove valuable to mind mapping in general, and to detecting patterns in any type of digital information.

Válság és hitelderivatívák. A szintetikus fedezett adósságkötelezettségek (CDO-k) árazása és kockázataik (Crisis and loan derivatives. The pricing and risks of synthetic collateralized debt obligations)

A dolgozat első részében röviden áttekintjük a 2007-ben kezdődött pénzügyi válság lefolyását és a válsághoz vezető okokat. A bemutatás során igyekszünk végig a mögöttes folyamatokra és azok mozgatórugóira koncentrálni, ezzel megragadva a válság egyfajta "elméletét". A bemutatásból láthatóvá válik a hitelderivatívák kiemelt szerepe a válság során. A dolgozat második részében az egyik legnépszerűbb hitelderivatív termék, a szintetikus fedezett adósságkötelezettségek (CDO-k) matematikai modellezését és annak problémáit mutatjuk be. Sokak szerint ezek a matematikai modellek okozták - vagy legalábbis felerősítették - a válságot. Az elemzés során megmutatjuk, hogy nemcsak a modellezési eszközök nem voltak megfelelők, hanem az árazás elve sem állta meg a helyét a kockázatsemleges árazási keretben. Ez az eredmény élesen rámutat a mögöttes elméletek válságára. / === / The first part of the paper examines briefly the financial crisis of 2007 and its causes, focusing on its driving processes and key motifs. This shows clearly the importance and centrality of credit derivatives in the crisis. The second part presents a mathematical modelling of one of the most popular credit derivative products: synthetic collateralized debt obligations, along with the drawbacks and problems of the modelling process. It is widely claimed that these products caused or at least precipitated the crises. The authors show not only that the modelling tools were inappropriate, but that the principle for pricing did not match adequately the risk-neutral valuation framework.

Környezeti kockázatok felmérése. Paraméterek bizonytalanságának hatása a kockázatkezelési döntéshozatalra = Assessment of environmental risks – effects of parameter uncertainty to the risk management decisions

A környezeti kockázatok megfelelő felmérése és kezelése napjaink egyik legfontosabb kérdése, nemcsak a szakmai, hanem a széles értelemben vett közvélemény számára. A szerző cikkében azt vizsgálja, hogy a környezeti kockázatok felmérésének milyen megközelítései vannak. Kulcskérdésként pedig arra koncentrál, hogy a kockázatkezelési döntéseket hogyan befolyásolja a becslések bizonytalansága. Először a környezeti kockázat definícióját adja meg, majd azt mutatja be, hogy a környezeti kockázatok kezelésére vonatkozó megközelítések milyen párhuzamban állnak a pénzügyi rendszerrel, mint komplex rendszerre vonatkozó megközelítésekkel. Végül a jelenleg legnagyobb kockázatoknak tartott környezeti kockázatokat ismerteti röviden. A cikk második részében kockázatkezelési alternatívákat mutat be, és azt, hogy a kockázatkezelési lépések kiválasztását befolyásolja a bizonytalanság. Ezt illusztrálandó Brouwer-Blois (2008) modelljét használva a soklépéses szimulációt és alternatív döntési kritériumot – a kritikus (extrém) költség-hatás mutatót – alkalmazza. _____________ Adequate assessment and management of environmental risks is a key question nowadays also for professional experts and also for the overall public. In this article the author examines the different approaches concerning environmental risks. He concentrates as a key question the influence on risk management decisions of uncertainties raised by our estimations. First he analyses the definition of environmental risks, and he shows the similarities and differences between approaches concerning environmental risks and risks threatening financial system, and finally he gives short overview on the most current environmental risks. In the second part of the paper he presents risk management alternatives and analyses the influential power of uncertainty on risk management decisions. In order to illustrate this phenomenon the author applies the model of Brouwer-Blois (2008) with multistep simulation and an alternative decisive criterion, the ranking based on critical (extreme) cost to effect measure.

Kockázatok a mezőgazdaságban (Risks in agriculture)

A szerző cikkében a mezőgazdaságban megjelenő kockázatokkal foglalkozik. Vizsgálja, hogy mely tényezők okoznak kockázatot e területen, illetve érinti a kockázat legsúlyosabb következményét, az éhínséget, csökkentésének módjait, valamint a mezőgazdasági biztosítás kérdését. ________ The paper analyzes the different types of risks appearing in agriculture. The paper aims to analyze both the factors that cause the risks and the most serious consequence of these risks, namely famine. The essay also tries to evaluate to possible ways risk can be decreased, especially with the focus on agricultural insurance.

Speciális kockázatok és kockázatkezelés a kockázatitőke-finanszírozásban (The special risks and risk management of venture capital)

A tanulmányban a szerzők arra a kérdésre keresik a választ, hogy az aszimmetrikus információk hatására a vállalkozók és a befektetők között kialakuló megbízó-ügynök viszonynak melyek a speciális vetületei a kockázatitőke-finanszírozás vonatkozásában. A szerzők arra a következtetésre jutottak, hogy a hiányos információk, a megbízó-ügynök viszony, illetve az ügyletek speciális jellege miatt fokozottan jelentkező ügynökprobléma kezelésére a kockázatitőke-finanszírozás szereplői speciális kockázatkezelési technikákat alkalmaznak. Ilyenek a magas elvárt hozamok, a szigorú kiválasztási kritériumok, a speciális befektetési vagy szindikátusi szerződések, a befektetést követő monitoring tevékenység, a több lépcsőben történő finanszírozás és a portfólióvállalatok hálózatba szervezése. A speciális kockázati megközelítés következtében a befektetéseket opciós szemlélet is áthatja. _____ This paper focuses on the special aspects of imperfect information in case of venture capital financing including principal-agent relationship between entrepreneurs and investors as well as adverse selection that evolves as a result of information asymmetries. The authors’ finding is that venture capital is able to manage the problems caused by imperfect information via applying divers risk management techniques such as high profit expectations, scrutiny of portfolio-companies, the use of special contracting stipulations and syndicate agreements, the monitoring of investments, multi-staged financing of companies and the integration of portfolio-companies into networks. In addition to the risk management techniques the authors also give the interpretation of the unique attitude of venture capital toward uncertainty and its special real option-like risk valuation approach that makes venture capitalists capable of handling high uncertainty under imperfect information.

A disztribúció kiszervezéséhez kapcsolódó ellátási és működési kockázatok (Supply and operational risks in the outsourcing of distribution management)

A cikk célja, hogy elemző bemutatását adja az ellátási láncok működéséhez, különösen a disztribúciós tevékenység kiszervezéséhez kapcsolódó működési kockázatoknak. Az írás első része az irodalomkutatás eredményeit feldolgozva az ellátási láncok kockázati kitettségének növekedése mögött rejlő okokat törekszik feltárni, s röviden bemutatja a vállalati kockázatkezelés lehetséges lépéseit e téren. A cikk második gondolati egysége mélyinterjúk segítségével összefoglalja és rendszerezi a disztribúció kiszervezéséhez kapcsolódó kockázatokat, számba veszi a kapcsolódó kockázatkezelési lehetőségeket, s bemutatja a megkérdezett vállalatok által alkalmazott kockázat-megelőzési alternatívákat. ______ The aim of this paper is to introduce operational risks of supply chains, especially risks deriving from the outsourcing of distribution management. Based on literature review the first part of the paper talks about the potential reasons of increasing global supply chain risks, and the general business activities of risk assessment. Analyzing the results of semi-structured qualitative interviews, the second part summarizes the risks belonging to the outsourcing of distribution and introduces the potential risk assessment and avoidance opportunities and alternatives in practice.