22 research outputs found
The power of wavelets in analysis of transit and phase curves in presence of stellar variability and instrumental noise III. Accuracy of transit parameters
Correlated noise in exoplanet light curves, such as noises from stellar
activity, convection noise, and instrumental noises distorts the exoplanet
transit light curves, and leads to biases in the best-fit transit parameters.
An optimal fitting algorithm is stable against the presence of correlated
noises and lead to statistically consistent results, i.e. the actual biases are
usually within the error interval. This is not automatically satisfied by most
of the algorithms in everyday use, and the testing of the algorithms is
necessary. In this paper, we describe a bootstrapping-like test to handle with
the general case, and apply this to the wavelet-based TLCM (Transit and Light
Curve Modeller) algorithm, testing it for the stability against the correlated
noise. We contrast the results to the FITSH algorithm that is based on a white
noise assumption. We simulated transit light curves with previously known
parameters in the presence of a correlated noise model generated by an ARIMA
(Autoregressive Integretad Moving Average) process. Then we solved the
simulated observations, and examined the resulting parameters and error
intervals. We have found that the assumption of FITSH that only white noise is
present led to inconsistencies in the results: the distribution of best-fit
parameters is by a factor of 3--6 broader then the determined error intervals.
On the other hand, the wavelet-based TLCM algorithm handles the correlated
noise properly, leading to properly determined parameter and error intervals
which are perfectly consistent with the actual biases.Comment: Submitted to A&A, favorable referee report received, 11 pages, 8
figure
Fractional flow reserve in below the knee arteries with critical limb ischemia and validation against gold-standard morphologic, functional measures and long term clinical outcomes.
INTRODUCTION: The aim of this study was to assess the applicability of fractional flow reserve measurement (FFR) in below-the-knee (BTK) arteries and to evaluate its correlation with non-invasive functional parameters before and after angioplasty. METHODS: We enrolled 39 patients with severe BTK arterial lesions. Inclusion criteria were critical limb ischemia (Rutherford 4-6) and angiographically proven arterial stenosis of the distal lower limb (percent diameter stenosis >/=70%). Exclusion criteria were chronic total occlusion, diabetic foot syndrome and non-viable distal lower limb. The transstenotic distal/proximal pressure ratio was measured under resting (Pd/Pa) and hyperemic (FFR) conditions induced by 40mg intra-arterial Papaverin and was compared with quantitative angiography-, laser Doppler- and duplex ultrasound-derived measurements before and after percutaneous angioplasty (PTA). RESULTS: Comparing measurements before and after PTA, we found significant improvements in the resting Pd/Pa values (0.79 [0.67-0.90] vs 0.90 [0.85-0.97]; p<0.001) and FFR values (0.60+/-0.19 vs 0.76+/-0.15; p<0.001), respectively. At baseline, Pd/Pa ratio and FFR were significantly albeit weakly correlated with % area stenosis (r:-0.31, p=0.05 and r:-0.31, p=0.05, respectively). After PTA, neither Pd/Pa nor FFR remained correlated with % area stenosis. Similarly, prior PTA, Pd/Pa ratio and FFR were significantly correlated with TcO2% and perfusion unit change (r:0.48, p<0.01 and r:0.34, p<0.05, respectively), but after intervention, these significant correlations vanished. Pd/Pa and FFR values did not show correlation with duplex ultrasound-derived measurements. At 1year, major adverse events (MAEs) and major adverse cardiovascular and cerebrovascular (MACCEs) were observed in 7 (17.9%) and in 9 (23.1%) patients, respectively. CONCLUSION: CLI due to severe BTK arterial disease was associated with several impediments of baseline pressure measurements which were significantly improved after successful PTA and stenting. Significant relationships between pressure data and functional and imaging parameters existed prior intervention but vanished after. Further studies are required to determine the clinical value of pre- and post-PTA pressure measurements in BTK arterial disease
Enabling planetary science across light-years. Ariel Definition Study Report
Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution
Employee selection methods in practice.
Dolgozatomban a szakirodalmi áttekintést követően különböző munkakör betöltésére irányuló kiválasztási folyamatot kívánom elemezni esettanulmány jelleggel. Az alkalmazott módszerek jellemzően kvalitatív adatgyűjtési technikák: személyes interjúkra, a rendelkezésemre bocsátott adatbázisok, illetve a toborzási, kiválasztási és beillesztési folyamat során keletkezett belső dokumentumok feldolgozására alapszik.Egy multinacionális cég által meghirdetett álláshirdetésekre jelentkezők kiválasztási módszereit mutattam be. Különböző munkakörbe kerestek nagy létszámú munkavállalói csoportot. Ebben a szegmensben lehetőségem nyílt a beválási statisztikák után követésére is a dolgozók éves teljesítménymutatóinak elemzésével, illetve a fluktuáció okainak elemzésére.MSc/MAVezetés és SzervezésK
A vezetői controlling szerepe a magyar Telekom zöld átmenetében
A kontrolling fő feladata, hogy a vezetés alrendszereként segítse azon döntések meghozatalát, amelyek lehetővé teszik a szervezeti célok elérését. Napjainkban az egyre fogyó erőforrások miatt a fenntarthatóság kérdése globális fókuszba került. A Magyar Telekom Csoport 2004 óta évente jelentésekben teszi közzé fenntarthatósági teljesítményéről szóló beszámolóját, melyek – az összehasonlíthatóság és elemezhetőség érdekében – szigorú nemzetközi szabályoknak megfelelően készülnek. A jelentések számos területet ölelnek fel. Ezek közül a gépjárműparkkal és járműhasználattal kapcsolatos döntéseket és azok pénzügyi, környezeti hatásait vizsgálja ez a tanulmány. Célja azoknak a vezetői döntéseknek az elemzése, amelyek a zöldebb és fenntarthatóbb
működést szolgálják ezen a területen. Az eredmények azt mutatják, hogy a járműpark évről-évre egyre zöldebb és korszerűbb. Ennek alapján a levonható legfőbb következtetés, hogy a zöld gondolkodásmód és a megalapozott társadalmi felelősségszemlélet alkalmazása a vezetői döntéshozatalban pozitív hatású a multinacionális vállalat közvetlen és globális környezetére egyaránt
The Human Factor of Information Security: Phishing in Cybercrime
У даній статті досліджується обізнаність громадськості щодо практики фішингу в Угорщині, наголошується на мінливому розвитку кіберзлочинності та стратегічній важливості інформації в сучасному суспільстві. Дослідження вивчає методи та фактори, що сприяють успішним схемам фішингу, використовуючи статистичні дані для покращення розуміння та механізмів захисту від таких атак. Заглиблюючись у методи та психологічні тригери, які використовуються для обману жертв, дослідження має на меті забезпечити всебічне уявлення про фішингові загрози. Дослідження вивчає, чи впливають демографічні відмінності, освіта та використання Інтернету на сприйнятливість до фішингових атак. Перевіряються два основні припущення: 1) демографічні фактори впливають на знання та ставлення до фішингу та 2) люди часто не розпізнають спроби фішингу. Підкреслюючи важливість захисту на основі процесів над суто технічними інструментами, дослідження підкреслює, що рішення та знання користувача є вирішальними для захисту від фішингу. Безпека на основі процесів, включаючи блокування шкідливих сайтів і сповіщення користувачів, має важливе значення, причому значна відповідальність лежить на постачальниках послуг, державних і національних органах безпеки. Однак роль користувача є критично важливою як найслабша ланка в ланцюжку безпеки. Обговорюються технологічні досягнення в методах захисту, зазначається, що в міру того, як ці методи стають ефективнішими, зловмисники зміщують увагу з систем на персонал, який ними керує. Ця зміна підкреслює зростаюче значення людського фактору в безпеці в Інтернеті. Інциденти фішингу часто залишаються непоміченими, оскільки компанії вважають за краще компенсувати збитки, а не виявляти вразливі місця, побоюючись значної втрати клієнтів. Дослідження підкреслює цінність інформації як мішені для злочинців, так і як важливого знання для запобігання. Захист даних і поширення знань є важливими завданнями в боротьбі з ІТ-злочинністю, що підкреслює необхідність постійних досліджень і підвищення обізнаності.
Ez a tanulmány az adathalász gyakorlatok köztudatát vizsgálja Magyarországon, hangsúlyozva a kiberbűnözés változó környezetét és az információ stratégiai fontosságát a mai társadalomban. A kutatás a sikeres adathalász sémákhoz hozzájáruló módszereket és tényezőket vizsgálja, statisztikai adatok felhasználásával az ilyen támadások megértésének és védekezésének javítására. Az áldozatok megtévesztésére használt technikák és pszichológiai kiváltó okok megismerésével a tanulmány átfogó képet kíván nyújtani az adathalász fenyegetésekről. A kutatás azt vizsgálja, hogy a demográfiai különbségek, az iskolai végzettség és az internethasználat befolyásolja-e az adathalász támadásokra való hajlamot. Két elsődleges feltevést tesztelünk: a demográfiai tényezők befolyásolják az adathalászattal kapcsolatos ismereteket és attitűdöket, és hogy az egyének gyakran nem ismerik fel az adathalász kísérleteket. A tanulmány kiemeli a folyamatalapú védelem fontosságát a tisztán technikai eszközökkel szemben, és hangsúlyozza, hogy a felhasználói döntések és ismeretek kulcsfontosságúak az adathalászat elleni védekezésben. A folyamatalapú biztonság, beleértve a rosszindulatú webhelyek blokkolását és a felhasználók értesítését, alapvető fontosságú, amely jelentős felelősséggel tartozik a szolgáltatókra, az állami és nemzetbiztonsági szervekre. A felhasználó szerepe azonban kritikus, mivel a biztonsági lánc leggyengébb láncszeme. Megvitatják a védelmi módszerek technológiai fejlődését, megjegyezve, hogy amint ezek a módszerek egyre hatékonyabbak, a támadók figyelmüket a rendszerekről az azokat üzemeltető személyzetre helyezik át. Ez az elmozdulás aláhúzza az emberi tényező növekvő jelentőségét az internetes biztonságban. Az adathalász incidenseket gyakran nem jelentik be, mivel a vállalatok inkább vállalják a veszteségeket, mintsem felfedjék a sebezhetőséget, tartva attól, hogy jelentős ügyfélveszteséget okoznak. A tanulmány hangsúlyozza az információ értékét, mind a bűnözők célpontjaként, mind pedig a megelőzés szempontjából kulcsfontosságú tudásként. Az adatok védelme és az ismeretek terjesztése alapvető feladat az informatikai bűnözés elleni küzdelemben, hangsúlyozva a folyamatos kutatás és tudatosság szükségességét.
This study investigates public awareness of phishing practices in Hungary, emphasizing the evolving landscape of cybercrime and the strategic importance of information in contemporary society. The research examines the methods and factors contributing to successful phishing schemes, employing statistical data to enhance understanding and defense mechanisms against such attacks. By delving into the techniques and psychological triggers used to deceive victims, the study aims to provide a comprehensive view of phishing threats. The research explores whether demographic differences, education, and internet use influence susceptibility to phishing attacks. Two primary assumptions are tested: that demographic factors affect knowledge and attitudes about phishing, and that individuals frequently fail to recognize phishing attempts. Highlighting the importance of process-based protection over purely technical tools, the study stresses that user decisions and knowledge are crucial in defending against phishing. Process-based security, including blocking malicious sites and notifying users, is essential, with a significant responsibility resting on service providers, state, and national security
agencies. However, the user's role is critical as the weakest link in the security chain. Technological advancements in defense methods are discussed, noting that as these methods become more effective, attackers shift their focus from systems to the personnel operating them. This shift underscores the increasing significance of the human factor in internet security. Phishing incidents often go unreported as companies prefer to absorb losses rather than reveal vulnerabilities, fearing significant customer
loss. The study emphasizes the value of information, both as a target for criminals and as crucial knowledge for prevention. Protecting data and disseminating knowledge are essential tasks in combating IT crime, underscoring the need for ongoing research and awareness
Tax Avoidance Methods of MNEs and Their Changes
Purpose: we examine the corporate tax willingness of multinational companies that operate on several continents and enjoy the benefits of globalization. One of these advantages is the establishment of subsidiaries in countries with favorable tax conditions. Thus, these MNEs deduct a significant part of their profits from tax liability. Only a fraction of the amount saved in this way is, however, used for sustainability purposes, while the states that lose the first tax revenue are forced to spend significant amounts on the same. Methodology: based on a literature review, we present the tax avoidance practices of MNEs based on a few selected examples (e.g. The double Irish with a Dutch sandwich), as well as the fact that these large companies almost create their own legal systems in order to withdraw themselves from state control, and even in possible countries also to decide political issues that will decide his fate. We also present the international cooperation under the leadership of the OECD, whose aim is to change the previous situation, to eliminate the tax procedure practices of MNEs and to involve these organizations in taxation.
Results: we report on the changes that indicate the transformation of MNEs' tax strategies towards cooperation.
Conclusions: MNEs are among the main winners and beneficiaries of globalization. In recent years and decades, with their economic power, they managed to achieve serious political influence, so that a large part of all their profits are excluded from the obligation to pay taxes. Since the law is always a step behind those who take advantage of legal loopholes, it has only been possible to achieve results through international cooperation in recent years. The willingness of MNEs to pay taxes is changing perceptibly, and the tax revenues from them will play a significant role in dealing with the problem of sustainability
Factors Shaping Tax Morale in Some European Countries
Purpose: in our time, the accelerating economic globalisation, and the profit-oriented market approach, as well as the consumer society, increasingly raise the question of the sustainability of the current situation. The solution is partly the responsibility of the companies shaping the situation, and partly of the state. Taxes, for example, cover the necessary state resources. In our work, we examine the factors that determine the willingness to pay taxes in several countries. Methodology: we selected our data from the publicly available surveys of the Deloitte company in five European countries and further research available in the literature. We were primarily interested in what kind of facilitations and discounts the examined countries try to increase tax incentives. Results: the tax morale in examined shows significant differences. Some of these are of historical-political origin: in the countries of the former communist bloc the distrust of the authorities. In Hungary, where the fiscal policy based on the theoretical rationality of taxation, the consequence is the decreasing trend of tax evasion. In traditional democracies, the historical factor has no role at all, the tax morale is rather influenced by the demographic characteristics of the individual. The cultural environment also has an effect. In Sweden, the tax policy is for the people and not the people for the taxes. The tax office is citizen-friendly, the tax law is transparent, and Swedes believe that the government uses their paid taxes to increase their well-being. In Italy, tax evasion is a widespread phenomenon. The reason for unfavorable tax morale is primarily the inefficient spending of public funds by local governments. Conclusions: the factors shaping tax morale vary from country to country based on geographical, cultural, and individual characteristics. Taking them into account is essential for the development of an effective tax policy
How are the Residents of the World's Largest Economies Taxed?
Purpose: Paying taxes is part of all of our lives. However, the phenomenon of tax evasion is not uncommon either. Therefore, each country makes its own rules to prevent tax evasion, whatever tax system it uses. The purpose of this work is to assess how the tax evasion issue is regulated in the examined countries, which are among the largest economies in the world. Methodology: We selected our data from the publicly available reports of the Deloitte company. The selection of countries therefore enables comparisons from several perspectives. The data were analysed using the results of further research available in the literature. We were primarily interested in the similarities and differences between the examined countries. Results: the examined countries regulate basically similar topics. They pay a lot of attention, for example, to the issue of transfer pricing and affiliated enterprises. However, the specific regulation sometimes shows significant differences. There are states that have adapted the OECD (Organization for Economic Co-operation and Development) anti-tax evasion rules into their domestic anti-tax evasion law. Other states combat the problem with special rules unique to them. Some of the differences are of historical and cultural origin: this is clearly demonstrated by China and Japan. Several groups can also be separated based on the general regulations against tax evasion. Conclusions: the willingness to avoid taxes is more or less characteristic of all companies and individuals. However, the actual tax evasion is fundamentally influenced by the applicable tax legislation. Getting to know and comparing the various regulations is also an opportunity for tax professionals and legislators from other countries, showing examples of methods to fight against tax evasion that should be followed or even avoided