Yes / This paper builds a framework to jointly examine the possibility of both `expansionary fiscal contractions' (austerity increasing output) and `fiscal free lunches' (expansions reducing government debt), arguments supported by the austerity and stimulus camps, respectively, in recent debates. We propose a new metric quantifying the budgetary implications of fiscal action, a key aspect of fiscal policy particularly at the monetary zero lower bound. We find that austerity needs to be highly persistent and credible to be expansionary, and stimulus temporary, responsive and well-targeted in order to lower debt. We conclude that neither are likely, especially during periods of economic distress.

Bipedal locomotion in humanoid robots is a very challenging problem within the field of robot locomotion. In this thesis, we propose and demonstrate an omni-directional walking engine that achieves stable walking using feedback from an inertial measurement unit. Our walking engine generates gaits for which the zero moment point is on the center of the supporting foot. The mechanical structure of CHARLI-L, a humanoid robot used as our test platform in this thesis, is first introduced by describing the inverse kinematics of its legs. The principles of the omni-directional gait generator that creates walking motions and overcomes the robot's mechanical deficiencies is discussed. We develop and implement two kinds of feedback controllers; one is the gait feedback controller and the other is the joint feedback controller. Both feedback controllers use proportional-derivative of the angle of the pelvis from an inertial measurement unit. The results of the experiments are presented the efficacy of our proposed walking engine. / Master of Science

No / In this work we present the work on the equalization algorithms to be used in future orthogonally multiplexed wavelets based multi signaling communication systems. The performance of ZF and MMSE algorithms has been analyzed using SISO and MIMO communication models. The transmitted electromagnetic waves were subjected through Rayleigh multipath fading channel with AWGN. The results showed that the performance of both of the above mentioned algorithms is the same in SISO channel but in MIMO environment MMSE has better performance.

<p dir="ltr">On this thesis, we study the validity of the Blackadar-Kirchberg conjecture for C*-<br>algebras that arise as extensions of separable, nuclear, quasidiagonal C*-algebras that satisfy<br>the Universal Coefficient Theorem. More specifically, we show that the conjecture for the<br>C*-algebra in the middle has an affirmative answer if the ideal lies in a class of C*-algebras<br>that is closed under local approximations and contains all separable ASH-algebras, as well<br>as certain classes of simple, unital C*-algebras and crossed products of unital C*-algebras<br>with Z. We also investigate when discrete, amenable groups have C*-algebras of real rank<br>zero. While it is known that this happens when the group is locally finite, the converse in<br>an open problem. We show that if C*(G) has real rank zero, then all normal subgroups of<br>G that are elementary amenable and have finite Hirsch length must be locally finite.<br><br></p>

In our study, we conduct a comparative analysis between dictionary-based sentiment analysis and entailment zero-shot text classification for German sentiment analysis. We evaluate the performance of a selection of dictionaries on eleven data sets, including four domain-specific data sets with a focus on historic German language. Our results demonstrate that, in the majority of cases, zero-shot text classification outperforms general-purpose dictionary-based approaches but falls short of the performance achieved by specifically fine-tuned models. Notably, the zero-shot approach exhibits superior performance, particularly in historic German cases, surpassing both general-purpose dictionaries and even a broadly trained sentiment model. These findings indicate that zero-shot text classification holds significant promise as an alternative, reducing the necessity for domain-specific sentiment dictionaries and narrowing the availability gap of off-the-shelf methods for German sentiment analysis. Additionally, we thoroughly discuss the inherent trade-offs associated with the application of these approaches.

2023 / Cryptographic protocols are usually designed using a modular approach, breaking down the task into several smaller tasks that involve constructing several cryptographic primitives. The next step is to identify primitives which serve the purpose and yet are simple enough to be instantiated. Simplicity can be defined in different ways - instantiable from a wider set of assumptions (or information-theoretically secure if possible), relaxed round complexity, and weaker security guarantees. However, finding the right way to break down the protocol into simpler primitives is not always easy. If the primitives are too simple, building the protocol becomes challenging. Conversely, if the primitives are too strong, it can be difficult to build them. Therefore, identifying the correct notion of "simplicity'', choosing the right set of primitives, and building the protocol requires a delicate balance. In this thesis, we revisit three problems in the areas of secure computation (MPC) and non-interactive zero-knowledge (NIZK) and we propose new ways to modularize the problems by relying on simpler primitives: 1. In the setting of two-party computation (2PC) where one of the participating parties is corrupted by a computationally unbounded adversary, we build a round-optimal 2PC protocol using a relaxed version of the oblivious transfer (which is not round-optimal) primitive and a non-interactive commitment scheme. 2. We build a round-optimal MPC protocol that withstands adaptive corruptions using an oblivious transfer which only provides sender and receiver privacy guarantees and satisfies some additional sampling properties. 3. We construct triply adaptive NIZKs which are secure against an adversary that corrupts parties and chooses statements to be proven in an adaptive way. We apply the Fiat-Shamir transform (instantiated using correlation intractable hash functions) to commitment-based Sigma protocols and demonstrate security in a modular way via a new approach for capturing universally-composable non-interactive commitments.

This Thesis is aimed at evaluating the options of renovation for an existing residential building to make it more energy efficient. The various aspects in the basic structures of residential homes are discussed in order to help the user identify the areas of the house for which renovation is required to improve the energy efficiency of the building. These aspects include doors, roof and wall in addition to various systems of electrical wiring, mechanical systems of ventilation, heating and cooling and plumbing systems for the efficient flow of water throughout the house. The renovation options have been described in detail to provide as many possibilities to the user as possible. The building taken for renovation is a 1953 suburban home which has been awarded the honor of being the first building to be labeled as Zero Energy Home in its vicinity. This has made the home so efficient that its expenditure of energy has become equivalent to its energy generation, therefore, cancelling each other out and creating an estimate of zero energy.

世界衛生組織表示「先前有過自殺行為的人，再度自殺的機率比一般人高」，因此如何針對自殺企圖者提供即時的關懷與介入服務，是世界各國重要的自殺防治策略之一。本研究希望針對曾有過自殺企圖的個案，經由統計模型的配適來找出自殺企圖個案的「自殺危險因子」，區別出再度自殺的高危險個案，以方便將人力及醫療資源投入到最需要被協助的個案上。 本研究的反應變項為「重複自殺企圖次數」，但是由於資料中「零值」的人數相當多，此外也呈現出變異數大於平均數的現象，因此我們採用可以同時處理Zero-inflated及Over-dispersion情況的廣義Zero-inflated卜瓦松迴歸模型 (Generalized Zero-inflated Poisson Regression Model)來進行資料的配適。我們得知重複自殺企圖之高風險因子有「65歲以上」、「曾患有精神疾病」、「不確定是否曾患有精神疾病」及「離婚」之個案，而「治癒」可能性較高的因子為「45~64歲」、「因情感因素自殺」、「已婚」之個案。藉由模型也可以進一步估計自殺企圖個案之再企圖機率，並且對自殺企圖個案進行分層，以進行不同程度的關懷與訪視，藉以提昇關懷的即時性及有效性。 / World Health Organization (WHO) has indicated that suicide attempt rate is much higher among those who have ever had suicide attempts. Hence, how to express concerns and provide timely consultations for suicide reattempters has become one of the key issues in suicide prevention. In this study, we try to identify the risk factors associated with suicide reattempters, and predict high-risk cases so that the limited resources can be distributed effectively. The primary variable of interest is the number of repeated suicide attempt for a suicide attempter after his/her index attempt. However, there are more zeros and greater variability in the data than that would be predicted by a Poisson model. We hence fit the data using a zero-inflated generalized Poisson regression model, a model that is frequently used for modeling over-dispersed count data with too many zeros. We find that the risk factors for repeated suicide attempts are those who are 65 or older, those who are classified as psychiatric disorders and those diagnostically uncertain cases, and those who are divorced. We also find that non-repeaters are more likely among those who are between 45 to 65 of age, married, and having a suicide attempt history due to an emotional reason. Through the use of the model, we can also estimate a subject’s reattempt probability, classify them, and provide them with suitable care and attention accordingly.

A dissertação pode ser dividida em duas partes: a primeira contém uma adaptação do modelo fenomenológico de Einstein conhecido como \"método dos coeficientes A e B\". As modificações são feitas no contexto da Eletrodinâmica Estocástica, uma teoria na qual as flutuações de ponto zero do campo eletromagnético são consideradas reais e clássicas. Nós obtemos, num estudo não relativístico e clássico, relações entre a energia e momento de partículas livres e a frequência da radiação transferida. Estas relações coincidem com as bem conhecidas relações que representam a conservação do quadrivetor momento-energia em espalhamento fóton-elétron. Na segunda parte nós tentamos descrever, de uma maneira qualitativa, o efeito Compton no espírito da Eletrodinâmica Estocástica. Encontramos indicações de que a ação combinada da força da reação da radiação e das flutuações de ponto zero é capaz de conferir à partícula carregada uma alta velocidade de recuo, e verificamos que a mesma é justamente a necessária para explanar o deslocamento da frequência observado como sendo devido ao efeito Doppler. Também calculamos a seção de choque diferencial para o espalhamento de radiação e encontramos a mesma expressão obtida por Compton no seu trabalho fundamental de 1923. / The dissertation may be divided in two parts: the first one contains an adaptation of Einstein\'s phenomenological model known as \"method of coefficients A and B\". The modifications are done in the framework of Stochastic Electrodynamics, a theory in wich the zero point fluctuations of the electromagnetic field are considered real and classical. We obtain, in a nonrelativistic and Classical approach, relations among the energy and momentum of free particles and the frequency of the exchanged radiation. These relations are coincident with the well known ones who depict the four-momentum conservation in photon-electron scattering. In the second part, we try to describe, in a qualitative manner, the Compton scattering in the spirit of Stochastic Electrodynamics. We find indications that the combined action of the radiation reaction force and the zero point flutuating field are able to give the charged particle a high recoil velocity, and we verify this one is just the necessary to explain the frequency shift as due to a double Doppler shift. We also calculate the differential cross section for the radiation scattering and we find the same expression as obtained by Compton in his fundamental work of 1023.

Neste trabalho estudou-se o uso do ferro de valência zero em meio redutivo e oxidativo, a fim de desenvolver um processo que promova tanto a degradação quanto a mineralização de substâncias orgânicas com centros deficientes de elétrons, como, por exemplo, espécies que contêm o grupo nitro ligado ao anel aromático. O processo de degradação empregando-se ferro metálico, em ambos os meios estudados, apresentou grande eficiência no tratamento do p-nitrofenol, utilizado como poluente modelo. Para soluções contendo concentração inicial de p-nitrofenol igual a 100 mg L-1, tanto para o meio redutivo quanto para o oxidativo, em condições ótimas, as taxas de degradação obtidas foram superiores a 98% ao final de 15 minutos de tratamento. Para o meio com atmosfera oxidante, foi possível observar a geração de H2O2 in situ (cerca de 0,030 mmol L-1, em 45 minutos), proporcionando uma reação do tipo Fenton. Dessa forma, foi possível obter uma redução do teor de carbono orgânico dissolvido de cerca de 20%, em 60 minutos de reação. A fim de elevar a taxa de mineralização do p-nitrofenol, realizou-se a integração dos processos redutivo e oxidativo. O emprego deste sistema de tratamento proporcionou um aumento de 100% na redução do teor de carbono orgânico dissolvido, para o mesmo tempo de tratamento. Assim, pode-se inferir que a associação dos processos estudados levou à formação de substâncias mais susceptíveis ao ataque de agentes oxidantes. Por fim, avaliou-se o emprego de ferro de valência zero sintetizado via redução de íons Fe2+ por boridreto de sódio. Utilizando-se o sistema de tratamento integrado, este material proporcionou uma taxa de mineralização de cerca de 50%, demonstrando-se como uma boa alternativa para a obtenção do ferro de valência zero. Dessa forma, pode-se concluir que o sistema integrado apresenta-se como uma alternativa viável e eficiente, com grande potencial de aplicabilidade para o tratamento de substâncias recalcitrantes aos processos de tratamento convencionais, uma vez que apresentou bons resultados na degradação/mineralização da substância modelo. / In this work, we studied the use of zero-valent iron under reductive and oxidative medium, in order to develop a process that promotes the degradation and the mineralization of organic substances with deficient electron centers, such as nitroaromatic compounds. In both mediums, the degradation process promoted by the metallic iron showed good efficiency to degrade p-itrophenol, used as pollutant model. For solutions of p-nitrophenol with initial concentration of 100 mg L-1, degradation percentages were above 98% after 15 minutes of the treatment in reductive and oxidative mediums (optimal conditions). Under oxidant atmosphere, the in situ generation of H2O2 (about 0,030 mmol L-1, in 45 minutes) leaded to a Fenton-like reaction. So, it provided a reduction of total organic carbon levels up to 20% in 60 minutes. In order to raise the mineralization of p-nitrophenol, the reductive and oxidative processes were integrated. The used of this treatment system provided an increase of 100% in the reduction of the dissolved organic carbon, for the same treatment time. Thus, we can in infer that the association of the two processes led to the formation of more susceptible substances to the attack of oxidant agents. Finally, it was evaluated the use zero-valent iron synthesized through reduction of Fe2+ ions by NaBH4. The obtained material provided about 50% of p-nitrophenol mineralization, showing to be a good source of zero-valent iron. So, it can be concluded that the use of the integrated system is a viable and efficient alternative, with a great potential of applicability for the treatment of recalcitrants substances to the conventional treatment processes, because it presented good results in the degradation/mineralization of studied pollutant model.