515 research outputs found

    How Important are Oil and Money Shocks in Explaining Housing Market Fluctuations in an Oil-exporting Country?: Evidence from Iran

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    This paper analyzes the effects of oil price and monetary shocks on the Iranian housing market in a Bayesian SVAR framework. The prior information for the contemporaneous identification of the SVAR model is derived from standard economic theory. To deal with uncertainty in the identification schemes, I calculate posterior model probabilities for the SVAR model identified by a different set of over-identification restrictions. In order to draw accurate inferences regarding the effectiveness of the shocks in an over-identified Bayesian SVAR, a Bayesian Monte Carlo integration method is applied. The findings indicate that oil price shocks explain a substantial portion of housing market fluctuations. Housing prices increase in response to a positive credit shock, but only with a noticeably smaller magnitude when compared with the response to a positive oil price shock.Housing market fluctuations, Oil price shocks, Credit shocks, Bayesian Structural VAR, Bayesian model averaging (BMA), Bayesian Monte Carlo integration method

    When cultural modifications are taken into account: Ibsen's a doll's house on Iranian screen

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    How cross-cultural communications terminate in imperfect understanding can arguably be rendered by critical awareness about culturally differentiating conceptions in the interacting communities. This study aims to shed light on how an awakening message of a Western literary work can achieve a functional realization in an Eastern society via domestication of the cultural mnemonics. To this end, the present paper explored how Henrik Ibsen's A Doll's House was introduced to Persian culture as a movie entitled Sara by Dariush Mehrjui mediated by apprehending the intended function of the original work and cultural capital of the target community. Meticulous comparative analysis of A Doll's House and Sara yielded that the given successful 'transmission' was materialized through two levels of macro contextual and micro cultural domestications. Generic and thematic transformations at the former level and various strata of cultural turns at the latter have conceivably lent verisimilitude to Sara and its proximity to the cultural schema of Iranian audience, through which Nora in Norway could be 'translated' to Sara in Iran to enlighten both audience. It is hoped the arguments of this research can offer some critical points for both proponents and opponents of the debates on cultural turn in generic translation. DOI: 10.5901/mjss.2015.v6n5s2p21

    Oscar Wilde as a temporal designer : a case study of the picture of Dorian Gray

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    Since the publication of Oscar Wilde’s The Picture of Dorian Gray, there have been great amounts of ideological criticism both for and against the author and the work. Critics have variously evaluated the work from different perspectives; however, these studies have largely targeted the thematic aspects of the novel, while little serious attempt has been made to examine the narrativity of this great work. As a result, the narrative structure of this novel still remains quite untouched. As a partial fulfillment, the present paper has examined the temporal structure of the novel. The analysis indicated that temporality is one of the very functional elements of the work. In fact, much of the meaning or the effect the author intends to converse through each action, character, or dialogue is firstly embedded in a proper and effective temporal setting. Moreover, the analysis ascertained that the well-set temporal structure of the work has resulted in (1) Ekphrasis, (2) Characterization, and (3) Reader manipulation. According to the paper, these three elements dramatically carry out the influentiality of this great novel

    Are public policies effective in alleviating family income inequality in Iran?

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    Redistributing incomes has always been one of the main goals of Iranian policy makers, although political regimes have changed frequently between 1991 and 2004. We have applied a microsimulation using the Oaxaca-Blinder decomposition and a Heckman correction for sample selection bias to compare simulation results for a hypothetical unchanged situation with the actual policy shift observed. While we are able to identify the years in which policy shifts occurred, our results suggest that the intended redistribution goals were at most partially achieved, affecting only some occupations and being offset by changes to the level of family incomes.Income Distribution, Policy Evaluation, Oaxaca-Blinder, Heckit

    Impact of Spasticity on Balance Control During Quiet Standing in Persons Post-Stroke

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    Statement of the problem: Balance impairments and falls are common among people with stroke. Muscle spasticity is also common and may influence balance control. However, the effect of spasticity on balance control among people with stroke is not well understood. Methods: Twenty-seven post-stroke individuals with low or high spasticity at the ankle completed quiet standing trials with eyes open and closed. Balance control was measured by estimating centre of pressure (COP) movement and trunk sway. Results: Individuals with high spasticity had greater COP velocity, trunk sway velocity, and trunk sway velocity frequency, particularly in the eyes closed condition. These effects were predominantly in the mediolateral direction (vision by group interaction effects p= 0.033, p= 0.037, and p= 0.015 respectively). Main effect of group revealed that individuals with high spasticity had higher mediolateral mean power frequency measures (p= 0.045). Conclusion: Individuals with high spasticity post-stroke demonstrated greater balance control challenges especially in absence of vision. Furthermore, these challenges were specifically noted in the frontal plane

    Enhancement of Secrecy of Block Ciphered Systems by Deliberate Noise

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    This paper considers the problem of end-end security enhancement by resorting to deliberate noise injected in ciphertexts. The main goal is to generate a degraded wiretap channel in application layer over which Wyner-type secrecy encoding is invoked to deliver additional secure information. More specifically, we study secrecy enhancement of DES block cipher working in cipher feedback model (CFB) when adjustable and intentional noise is introduced into encrypted data in application layer. A verification strategy in exhaustive search step of linear attack is designed to allow Eve to mount a successful attack in the noisy environment. Thus, a controllable wiretap channel is created over multiple frames by taking advantage of errors in Eve's cryptanalysis, whose secrecy capacity is found for the case of known channel states at receivers. As a result, additional secure information can be delivered by performing Wyner type secrecy encoding over super-frames ahead of encryption, namely, our proposed secrecy encoding-then-encryption scheme. These secrecy bits could be taken as symmetric keys for upcoming frames. Numerical results indicate that a sufficiently large secrecy rate can be achieved by selective noise addition.Comment: 11 pages, 8 figures, journa

    Application of Optimal Switching Using Adaptive Dynamic Programming in Power Electronics

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    In this dissertation, optimal switching in switched systems using adaptive dynamic programming (ADP) is presented. Two applications in power electronics, namely single-phase inverter control and permanent magnet synchronous motor (PMSM) control are studied using ADP. In both applications, the objective of the control problem is to design an optimal switching controller, which is also relatively robust to parameter uncertainties and disturbances in the system. An inverter is used to convert the direct current (DC) voltage to an alternating current (AC) voltage. The control scheme of the single-phase inverter uses a single function approximator, called critic, to evaluate the optimal cost and determine the optimal switching. After offline training of the critic, which is a function of system states and elapsed time, the resulting optimal weights are used in online control, to get a smooth output AC voltage in a feedback form. Simulations show the desirable performance of this controller with linear and nonlinear load and its relative robustness to parameter uncertainty and disturbances. Furthermore, the proposed controller is upgraded so that the inverter is suitable for single-phase variable frequency drives. Finally, as one of the few studies in the field of adaptive dynamic programming (ADP), the proposed controllers are implemented on a physical prototype to show the performance in practice. The torque control of PMSMs has become an interesting topic recently. A new approach based on ADP is proposed to control the torque, and consequently the speed of a PMSM when an unknown load torque is applied on it. The proposed controller achieves a fast transient response, low ripples and small steady-state error. The control algorithm uses two neural networks, called critic and actor. The former is utilized to evaluate the cost and the latter is used to generate control signals. The training is done once offline and the calculated optimal weights of actor network are used in online control to achieve fast and accurate torque control of PMSMs. This algorithm is compared with field-oriented control (FOC) and direct torque control based on space vector modulation (DTC-SVM). Simulations and experimental results show that the proposed algorithm provides desirable results under both accurate and uncertain modeled dynamics

    Achievable secrecy enchancement through joint encryption and privacy amplification

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    In this dissertation we try to achieve secrecy enhancement in communications by resorting to both cryptographic and information theoretic secrecy tools and metrics. Our objective is to unify tools and measures from cryptography community with techniques and metrics from information theory community that are utilized to provide privacy and confidentiality in communication systems. For this purpose we adopt encryption techniques accompanied with privacy amplification tools in order to achieve secrecy goals that are determined based on information theoretic and cryptographic metrics. Every secrecy scheme relies on a certain advantage for legitimate users over adversaries viewed as an asymmetry in the system to deliver the required security for data transmission. In all of the proposed schemes in this dissertation, we resort to either inherently existing asymmetry in the system or proactively created advantage for legitimate users over a passive eavesdropper to further enhance secrecy of the communications. This advantage is manipulated by means of privacy amplification and encryption tools to achieve secrecy goals for the system evaluated based on information theoretic and cryptographic metrics. In our first work discussed in Chapter 2 and the third work explained in Chapter 4, we rely on a proactively established advantage for legitimate users based on eavesdropper’s lack of knowledge about a shared source of data. Unlike these works that assume an errorfree physical channel, in the second work discussed in Chapter 3 correlated erasure wiretap channel model is considered. This work relies on a passive and internally existing advantage for legitimate users that is built upon statistical and partial independence of eavesdropper’s channel errors from the errors in the main channel. We arrive at this secrecy advantage for legitimate users by exploitation of an authenticated but insecure feedback channel. From the perspective of the utilized tools, the first work discussed in Chapter 2 considers a specific scenario where secrecy enhancement of a particular block cipher called Data Encryption standard (DES) operating in cipher feedback mode (CFB) is studied. This secrecy enhancement is achieved by means of deliberate noise injection and wiretap channel encoding as a technique for privacy amplification against a resource constrained eavesdropper. Compared to the first work, the third work considers a more general framework in terms of both metrics and secrecy tools. This work studies secrecy enhancement of a general cipher based on universal hashing as a privacy amplification technique against an unbounded adversary. In this work, we have achieved the goal of exponential secrecy where information leakage to adversary, that is assessed in terms of mutual information as an information theoretic measure and Eve’s distinguishability as a cryptographic metric, decays at an exponential rate. In the second work generally encrypted data frames are transmitted through Automatic Repeat reQuest (ARQ) protocol to generate a common random source between legitimate users that later on is transformed into information theoretically secure keys for encryption by means of privacy amplification based on universal hashing. Towards the end, future works as an extension of the accomplished research in this dissertation are outlined. Proofs of major theorems and lemmas are presented in the Appendix

    An analysis of population growth in Isfahan City since 1956

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    This thesis mainly analyses the very rapid annual growth (4.5 percent) of population in Isfahan City since 1956, and is divided into nine chapters. In a preliminary analysis of the historical background of population fluctuations throughout the centuries, the unofficial and unreliable estimates of travellers and visitors have been examined. Subsequently, an effort has been made to understand the influence upon population growth of the changing economic characteristics of the city, notably the increasing numbers of factories and workshops and particularly the new steal mill, which have attracted numerous migrants, largely from the rural areas and smaller towns around Isfahan City. The thesis is also concerned with the population composition and structure in Isfahan City, and the way that sex composition, age structure and marital status influence population growth. Consideration is then given to measuring the influence of natural increase on the population growth, particularly the two basic elements of births and deaths in the city and their changes over a period of twenty years. The evolution of families and households in the city has been surveyed, which has revealed an interesting reduction in the number of extended families and the increase in the number of smaller nuclear families. Finally the pattern of areal expansion of the city since the 17th century has been considered, especially to see the relationships between population growth and areal expansion. The main difficulty throughout the study was the lack of reliable census and vital registration data for Iran as a whole and also for Isfahan City. Therefore a wide variety of sources had to be used
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