Effect of dynamical instability on timing jitter in passively mode-locked quantum-dot lasers

We study the effect of noise on the dynamics of passively mode-locked semiconductor lasers both experimentally and theoretically. A method combining analytical and numerical approaches for estimation of pulse timing jitter is proposed. We investigate how the presence of dynamical features such as wavelength bistability in a quantum-dot laser affects timing jitter.

The Long-Term impact of Business Support? - Exploring the Role of Evaluation Timing using Micro Data

The original contribution of this work is threefold. Firstly, this thesis develops a critical perspective on current evaluation practice of business support, with focus on the timing of evaluation. The general time frame applied for business support policy evaluation is limited to one to two, seldom three years post intervention. This is despite calls for long-term impact studies by various authors, concerned about time lags before effects are fully realised. This desire for long-term evaluation opposes the requirements by policy-makers and funders, seeking quick results. Also, current ‘best practice’ frameworks do not refer to timing or its implications, and data availability affects the ability to undertake long-term evaluation. Secondly, this thesis provides methodological value for follow-up and similar studies by using data linking of scheme-beneficiary data with official performance datasets. Thus data availability problems are avoided through the use of secondary data. Thirdly, this thesis builds the evidence, through the application of a longitudinal impact study of small business support in England, covering seven years of post intervention data. This illustrates the variability of results for different evaluation periods, and the value in using multiple years of data for a robust understanding of support impact. For survival, impact of assistance is found to be immediate, but limited. Concerning growth, significant impact centres on a two to three year period post intervention for the linear selection and quantile regression models – positive for employment and turnover, negative for productivity. Attribution of impact may present a problem for subsequent periods. The results clearly support the argument for the use of longitudinal data and analysis, and a greater appreciation by evaluators of the factor time. This analysis recommends a time frame of four to five years post intervention for soft business support evaluation.

The long-term impact of business support? - Exploring the role of evaluation timing using micro data

The original contribution of this work is threefold. Firstly, this thesis develops a critical perspective on current evaluation practice of business support, with focus on the timing of evaluation. The general time frame applied for business support policy evaluation is limited to one to two, seldom three years post intervention. This is despite calls for long-term impact studies by various authors, concerned about time lags before effects are fully realised. This desire for long-term evaluation opposes the requirements by policy-makers and funders, seeking quick results. Also, current ‘best practice’ frameworks do not refer to timing or its implications, and data availability affects the ability to undertake long-term evaluation. Secondly, this thesis provides methodological value for follow-up and similar studies by using data linking of scheme-beneficiary data with official performance datasets. Thus data availability problems are avoided through the use of secondary data. Thirdly, this thesis builds the evidence, through the application of a longitudinal impact study of small business support in England, covering seven years of post intervention data. This illustrates the variability of results for different evaluation periods, and the value in using multiple years of data for a robust understanding of support impact. For survival, impact of assistance is found to be immediate, but limited. Concerning growth, significant impact centres on a two to three year period post intervention for the linear selection and quantile regression models – positive for employment and turnover, negative for productivity. Attribution of impact may present a problem for subsequent periods. The results clearly support the argument for the use of longitudinal data and analysis, and a greater appreciation by evaluators of the factor time. This analysis recommends a time frame of four to five years post intervention for soft business support evaluation.

Does timing of decisions in a mixed duopoly matter?

We determine the endogenous order of moves in a mixed pricesetting duopoly. In contrast to the existing literature on mixed oligopolies we establish the payo equivalence of the games with an exogenously given order of moves if the most plausible equilibrium is realized in the market. Hence, in this case it does not matter whether one becomes a leader or a follower. We also establish that replacing a private firm by a public firm in the standard Bertrand-Edgeworth game with capacity constraints increases social welfare and that a pure-strategy equilibrium always exists.

A költségvetési korlát megkeményítése a posztszocialista országokban = Hardening of the budget constraint in the post-socialist countries

A költségvetési korlát megkeményítése nem egyforma mértékben ment végbe minden posztszocialista gazdaságban. Egyes országokban messzire jutottak ebben a tekintetben, másokban viszont alig változott az indulóállapot. A tanulmány áttekinti a költségvetési korlát puhaságának különböző megnyilvánulásait: az állami támogatásokat, a puha adózást, a nem teljesítő bankkölcsönöket, a vállalatközi tartozások felgyülemlését és a kifizetetlen béreket. A jelenséget sokféle tényező okozza, amelyek többnyire együttesen jelentkeznek. Az állami tulajdon fenntartása kedvez a puha költségvetési szindróma megrögződésének, a privatizálás elősegíti a keményítést, de nem elégséges feltétele a kemény korlát érvényesítésének. Ehhez megfelelő politikai, jogi és gazdasági környezetet kell céltudatosan kialakítani. A posztszocialista átmenet kezdetén sokan azt hitték, hogy a hatékony piacgazdaság létrehozásához elegendő lesz megvalósítani a liberalizáció, privatizáció és stabilizáció "szentháromságát". Mára már kiderült, hogy a költségvetési korlát megkeményítése az említett három feladattal egyenrangúan fontos. Ahol ez nem valósul meg (például Oroszország), ott a privatizáció nem hozza meg a várt eredményt. ___________________ The budget constraint has not hardened to equal degrees in the various post-socialist countries. In some of them, a great deal has been done in this respect, while in others there has been hardly any change from the initial state. This study surveys the typical manifestations of softness of the budget constraint, such as state subsidies, soft taxation, non-performing loans, the accumulation of trade arrears between firms, and the build-up of wage arrears. Softness of the budget constraint is caused by several factors that tend to act in combination. Thus retention of state ownership helps to preserve the soft budget-constraint syndrome, while privatization encourages the budget constraint to harden, although it does not form a sufficient condition for it to happen. Purposeful development of the requisite political, legal and economic conditions is also required. It was widely maintained at the outset of the post-socialist transition that the 'Holy Trinity' of liberalization, privatization and stabilization would suffice to produce an efficient market economy. Since then, it has become clear that hardening the budget constraint needs to be given equal priority with these. Otherwise, the effects of privatization will fall short of expectations, as they have in Russia, for example.

A puha költségvetési korlát szindrómája a kórházi szektorban = The soft budget constraint syndrome in the hospital sector

A kutatások eddig főképpen azt vizsgálták, hogyan jelenik meg a puha költségvetési korlát szindrómája a vállalati szférában és a hitelrendszerben. A jelen cikk a kórházi szektorra összpontosítja a figyelmet. Leírja az események öt főszereplőjének, a betegnek, az orvosnak, a kórházigazgatónak, a politikusnak és a kórház tulajdonosának motivációit és magatartásuk ellentmondásos jellegét. A motivációk magyarázzák, miért olyan erőteljes a túlköltési hajlam és a költségvetési korlát felpuhulásának tendenciája. A döntési és finanszírozási folyamatok minden szintjén felfelé hárítják a túlköltés és eladósodás terheit. A cikk kitér a különböző tulajdonformák (állami, nonprofit és forprofit nem állami tulajdonformák) és a puha költségvetési korlát szindrómájának kapcsolatára. Végül normatív szempontból vizsgálja a jelenséget: melyek a költségvetési korlát megkeményítésének kedvező és kedvezőtlen következményei, és hogyan tükröződnek a normatív dilemmák az események résztvevőinek tudatában. ___________ Researches so far have examined mainly how the soft budget constraint syndrome appears in the corporate sphere and the credit system. This article concentrates on the hospital sector. It describes the motivations and the contradictory behaviour of the five main types of participant in the events: patients, doctors, hospital managers, politicians, and hospital owners. The motivations explain why the propensity to overspend and the tendency to soften the budget constraint are so strong. The burdens of overspending and indebtedness are pushed upwards at every level of the decision-making and funding processes. The article considers the connection between the soft budget constraint syn-drome and the various forms of ownership (state ownership and the non-profit and for-profit forms of non-state ownership). Finally, the phenomenon is examined from the normative point of view: what are the favourable and unfavourable consequences of hardening the budget constraint and how these are reflected in the consciousness of the participants in the normative dilemmas and events.

Endogenous timing of moves in an asymmetric price-setting duopoly

This paper adds to the growing literature on endogenous timing of decisions in duopolies. We show for a price-setting duopoly game with sufficiently asymmetric and strictly convex cost functions that the less efficient firm moves first while the more efficient moves second with a higher price than the less efficient firm.

Endogenous Timing of Moves in Bertrand-Edgeworth Triopolies

We determine the endogenous order of moves in which the firms set their prices in the framework of a capacity-constrained Bertrand-Edgeworth triopoly. A three-period timing game that determines the period in which the firms announce their prices precedes the price-setting stage. We show for the non-trivial case (in which the Bertrand-Edgeworth triopoly has only an equilibrium in non-degenerated mixed-strategies) that the firm with the largest capacity sets its price first, while the two other firms set their prices later. Our result extends a finding by Deneckere and Kovenock (1992) from duopolies to triopolies. This extension was made possible by Hirata's (2009) recent advancements on the mixed-strategy equilibria of Bertrand-Edgeworth games.

The Soft Budget Constraint. An introductory study to volume IV of the Life’s Work series

The author’s ideas on the soft budget constraint (SBC) were first expressed in 1976. Much progress has been made in understanding the problem over the ensuing four decades. The study takes issue with those who confine the concept to the process of bailing out loss-making socialist firms. It shows how the syndrome can appear in various organizations and forms in many spheres of the economy and points to the various means available for financial rescue. Single bailouts do not as such generate the SBC syndrome. It develops where the SBC becomes built into expectations. Special heed is paid to features generated by the syndrome in rescuer and rescuee organizations. The study reports on the spread of the syndrome in various periods of the socialist and the capitalist system, in various sectors. The author expresses his views on normative questions and on therapies against the harmful effects. He deals first with actual practice, then places the theory of the SBC in the sphere of ideas and models, showing how it relates to other theoretical trends, including institutional and behavioural economics and theories of moral hazard and inconsistency in time. He shows how far the intellectual apparatus of the SBC has spread in theoretical literature and where it has reached in the process of “canonization” by the economics profession. Finally, he reviews the main research tasks ahead.

Introduction of soft budget constraint as an analyzing tool into public management. The case of the Hungarian public administration reform

Public management reforms are usually underpinned by arguments that they will make the public administration system more effective and efficient. In practice, however, it is very hard to determine whether a given reform will improve the efficiency and effectiveness of the public administration system in the long run. Here, I shall examine how the concept of the soft budget constraint (SBC) introduced by János Kornai (Kornai 1979, 1986; Kornai, Maskin & Roland 2003) can be applied to this problem. In the following, I shall describe the Hungarian public administration reforms implemented by the Orbán government from 2010 onward and analyze its reforms, focusing on which measures harden and which ones soften the budget constraint of the actors of the Hungarian public administration system. In the literature of economics, there is some evidence-based knowledge on how to harden/soften the budget constraint, which improves/reduces the effectiveness and hence the efficiency of the given system. By using the concept of SBC, I also hope to shed some light on the rationale behind the Hungarian government’s introduction of such a contradictory reform package. Previously, the concept of SBC was utilized narrowly in public management studies, mostly in the field of fiscal federalism. My goal is to apply the concept to a broader area of public management studies. My conclusion is that the concept of SBC can significantly contribute to public management studies by deepening our knowledge on the reasons behind the success and failure of public administration reforms.

Earnings management using estimates and the timing of adoption of accounting standards: An empirical examination of pensions

This study investigates the relationship between adoption timing of Statement of Financial Accounting Standards 87 and earnings management after adoption. Earnings management, defined consistent with Schipper (1989), is tested through hypotheses using (1) a portfolio approach and (2) pension rates. One Hypothesis uses a Modified Jones (1991) Model as a proxy for discretionary accruals and the other uses pension rate estimates.^ Statistically significant relationships are found between adoption timing and (1) discretionary accruals and (2) estimated rate-of-return (ROR) on pension plan assets. Early adopting firms tend to have lower discretionary accruals after adoption than on-time adopters. They also tend to use higher ROR estimates which are not supported by higher actual returns. Thus, while early adopters may be using ROR to manage income, this tends to not result in higher discretionary accruals. ^

Prenatal augmented auditory stimulation and visual system development: Effects of timing on intersensory organization

This study investigated the effects of augmented prenatal auditory stimulation on postnatal visual responsivity and neural organization in bobwhite quail (Colinus virginianus). I delivered conspecific embryonic vocalizations before, during, or after the development of a multisensory, midbrain audiovisual area, the optic tectum. Postnatal simultaneous choice tests revealed that hatchlings receiving augmented auditory stimulation during optic tectum development as embryos failed to show species-typical visual preferences for a conspecific maternal hen 72 hours after hatching. Auditory simultaneous choice tests showed no hatchlings had deficits in auditory function in any of the groups, indicating deficits were specific to visual function. ZENK protein expression confirmed differences in the amount of neural plasticity in multiple neuroanatomical regions of birds receiving stimulation during optic tecturn development, compared to unmanipulated birds. The results of these experiments support the notion that the timing of augmented prenatal auditory stimulation relative to optic tectum development can impact postnatal perceptual organization in an enduring way.^

Population viability analyses of Chamaecrista keyensis (Leguminosae: Caesalpinioideae), a narrowly endemic herb of the lower Florida Keys: Effects of seasonal timing of fires and the urban -wildland interface

This research first evaluated the effects of urban wildland interface on reproductive biology of the Big Pine Partridge Pea, Chamaecrista keyensis, an understory herb that is endemic to Big Pine Key, Florida. I found that C. keyensis was self-compatible, but depended on bees for seed set. Furthermore, individuals of C. keyensis in urban habitats suffered higher seed predation and therefore set fewer seeds than forest interior plants. ^ I then focused on the effects of fire at different times of the year, summer (wet) and winter (dry), on the population dynamics and population viability of C. keyensis. I found that C. keyensis population recovered faster after winter burns and early summer burns (May–June) than after late summer burns (July–September) due to better survival and seedling recruitment following former fires. Fire intensity had positive effects on reproduction of C. keyensis. In contrast, no significant fire intensity effects were found on survival, growth, and seedling recruitment. This indicated that better survival and seedling recruitment following winter and early summer burns (compared with late summer burns) were due to the reproductive phenology of the plant in relation to fires rather than differences in fire intensity. Deterministic population modeling showed that time since fire significantly affected the finite population growth rates (λ). Particularly, recently burned plots had the largest λ. In addition, effects of timing of fires on λ were most pronounced the year of burn, but not the subsequent years. The elasticity analyses suggested that maximizing survival is an effective way to minimize the reduction in finite population growth rate the year of burn. Early summer fires or dry-season fires may achieve this objective. Finally, stochastic simulations indicated that the C. keyensis population had lower extinction risk and population decline probability if burned in the winter than in the late summer. A fire frequency of approximately 7 years would create the lowest extinction probability for C. keyensis. A fire management regime including a wide range of burning seasons may be essential for the continued existence of C. keyensis and other endemic species of pine rockland on Big Pine Key. ^

Real-time scheduling of embedded applications on multi-core platforms

For the past several decades, we have experienced the tremendous growth, in both scale and scope, of real-time embedded systems, thanks largely to the advances in IC technology. However, the traditional approach to get performance boost by increasing CPU frequency has been a way of past. Researchers from both industry and academia are turning their focus to multi-core architectures for continuous improvement of computing performance. In our research, we seek to develop efficient scheduling algorithms and analysis methods in the design of real-time embedded systems on multi-core platforms. Real-time systems are the ones with the response time as critical as the logical correctness of computational results. In addition, a variety of stringent constraints such as power/energy consumption, peak temperature and reliability are also imposed to these systems. Therefore, real-time scheduling plays a critical role in design of such computing systems at the system level. We started our research by addressing timing constraints for real-time applications on multi-core platforms, and developed both partitioned and semi-partitioned scheduling algorithms to schedule fixed priority, periodic, and hard real-time tasks on multi-core platforms. Then we extended our research by taking temperature constraints into consideration. We developed a closed-form solution to capture temperature dynamics for a given periodic voltage schedule on multi-core platforms, and also developed three methods to check the feasibility of a periodic real-time schedule under peak temperature constraint. We further extended our research by incorporating the power/energy constraint with thermal awareness into our research problem. We investigated the energy estimation problem on multi-core platforms, and developed a computation efficient method to calculate the energy consumption for a given voltage schedule on a multi-core platform. In this dissertation, we present our research in details and demonstrate the effectiveness and efficiency of our approaches with extensive experimental results.

Evaluating the effectiveness of signal timing optimization based on microscopic simulation evaluation

The optimization of the timing parameters of traffic signals provides for efficient operation of traffic along a signalized transportation system. Optimization tools with macroscopic simulation models have been used to determine optimal timing plans. These plans have been, in some cases, evaluated and fine tuned using microscopic simulation tools. A number of studies show inconsistencies between optimization tool results based on macroscopic simulation and the results obtained from microscopic simulation. No attempts have been made to determine the reason behind these inconsistencies. This research investigates whether adjusting the parameters of macroscopic simulation models to correspond to the calibrated microscopic simulation model parameters can reduce said inconsistencies. The adjusted parameters include platoon dispersion model parameters, saturation flow rates, and cruise speeds. The results from this work show that adjusting cruise speeds and saturation flow rates can have significant impacts on improving the optimization/macroscopic simulation results as assessed by microscopic simulation models.