An Econometric Evaluation of A Geopolitical Theory of Oil Price Behavior

WP 2005-27 December 2005Previous work on crude oil price modeling has generally focused on two theoretical approaches, either the optimal control analysis of pricing of a depletable resource, or OPEC as a partial monopolist setting oil prices to maximize net present value. Neither has been wholly satisfactory. We consider a different perspective, a game theory based framework in which political and military factors interact with economic considerations for oil exporters and importers to define a target price zone (TPZ). We analyze several issues in this context: monthly vs. annual average prices, beginning and ending dates for TPZs, degree of stability in several price series (WTI, Brent, etc.), FOB and landed prices, real or nominal prices, OPEC behavior, and effect of the Euro exchange rate on dollar denominated oil prices. We conclude that a TPZ system was in operation from 1986 through 2003 and that OPEC acted as a political cartel exercising market power by controlling production in order to seek to maintain prices within the TPZ. The TPZ worked imperfectly but with a substantial degree of predictability for 18 years. In 2004 and 2005 the TPZ system deteriorated for several reasons, and has not yet been re-established

تقييم أداء بعض المتحكمات في الشبكات المعرفة برمجياً بما يخدم التوسعية والبنية الموزعة

تعتبر الشبكات المعرفة برمجياً Software Defined Networks (SDN) من البنى الشبكية الحديثة والتي تتصف بالمرونة والديناميكية وتوفير الموارد وسهولة الإدارة. تعتبر بنية شبكة SDN كتمثيل لشبكة تم فصل قرارات التحكم فيها عن قرارات التوجيه. يركز هذا البحث على دراسة أداء ثلاث متحكمات رئيسية هي متحكم POX المبرمج بلغة Python، ومتحكم MUL المبرمج بلغة C، ومتحكم OpenDayLight المبرمج بلغة JAVA. تمت عمليات دراسة الأداء لهذه المتحكمات في أربع بنى مختلفة من شبكات SDN، وهي البنية الوحيدة والخطية والشجرية وبنية رابعة قمنا باقتراحها، حيث تركزت عمليات مقارنة الأداء من خلال قياس عاملين هما: الإنتاجية Throughput وزمن الرحلة  Round Trip Time.  تمت عمليات المقارنة باستخدام المحاكي الشبكي Mininet.  بينت النتائج أن  متحكم OpenDayLight يعطي أداءاً أفضل من متحكم POX في جميع البنى المدروسة، و أداءاً أفضل من متحكم MUL في ثلاث من البنى الأربع المدروسة وفق العاملين الذين قمنا بدراستهما وفي البيئات المتنوعة التي تمت الدراسة فيها

Mental wellbeing of frontline health workers post-pandemic: lessons learned and a way forward

ObjectiveTo assess the state of mental wellbeing among medical and dental frontline health workers as the COVID-19 pandemic transitions to an endemic phase and to determine what employer-provided intervention strategies these workers perceive as effective and desirable to improve their mental wellbeing.MethodsAn anonymous online survey distributed to frontline health workers in a hospitalist program of a tertiary care medical center and a university dental school in Minnesota in September 2022. The survey contained validated tools to measure depression severity, levels of perceived stress, and mental health status as well as questions to determine effective strategies to improve emotional wellbeing among these health workers. Data was evaluated on an aggregate level as well as stratified by level (e.g., physician, staff) and field (e.g., medicine, dentistry).ResultsOn average, all groups of health workers suffered from moderate to moderately severe depression, had a much higher perceived stress level than average, and had a fair mental health status. There were no significant differences in depression severity, stress level, or mental health status among physicians, dentists, medical staff, and dental staff. The majority of the respondents perceived adjusted work hours, rewards and incentives, and teamwork as the most effective and desirable strategies to improve their mental wellbeing.ConclusionThe current mental wellbeing of frontline health workers is poor. Many are dissatisfied with healthcare and consider leaving the industry. To improve their employees’ mental wellbeing, healthcare employers might want to consider adjusted work hours, rewards, and teamwork as these intervention strategies are perceived as most effective and desirable by the intended recipients

Evaluating User Interface Management Systems based on Quality Attributes and Unit Operations

Software architecture is an essential early stage in the software design process. In this stage, the architect should give the quality attributes a special consideration because a good level of meeting these attributes can be performed by well-designed architecture. This means that there is a close relationship between quality attributes and software architecture. However, quality attributes can be achieved through the appropriate application of a set of unit operations. A unit operation is a systematic designing operation that can be applied directly to system architecture. Architectural styles (patterns) include high level design decisions that address quality attributes. Many general architectural styles are defined in the literature. For the domain of user interactive systems there are many architectural styles that address some important quality attributes. In many cases, it is essential to evaluate software styles in terms of their achievement of the required quality attributes by analyzing the relationships between these attributes, unit operations, and styles. This evaluation can help and facilitate the process of selecting a specified style. In this paper the authors propose a structured quantitative evaluation method to show a rank of four wellknown user interface management systems (UIMSs) in terms of their supporting a set of six important selected quality attributes

A Framework for Selecting Architectural Tactics Using Fuzzy Measures

Software architects cannot avoid the consideration of quality attributes when designing software architecture. Architectural styles such as Layers and Client-Server are often used by architects to describe the overall structure and behavior of software. Although an architectural style affects the achievement of quality attributes, these quality attributes are directly performed by design decisions called architectural tactics. While the implementation of an architectural tactic supports a specific quality attribute, it often enhances or hurts other quality attributes in the software. In this paper, a framework for selecting the most appropriate architectural tactics according to their best achievement of the required levels of quality attributes when developing transaction processing systems is proposed. The proposed framework is based on fuzzy measures using Choquet Integral approach and takes into account the impact of

ISO9126 BASED SOFTWARE QUALITY EVALUATION USING CHOQUET INTEGRAL

Evaluating software quality is an important and essential issue in the development process because it helps to deliver a competitive software product. A decision of selecting the best software based on quality attributes is a type of multi-criteria decision-making (MCDM) processes where interactions among criteria should be considered. This paper presents and develops quantitative evaluations by considering interactions among criteria in the MCDM problems. The aggregator methods such as Arithmetic Mean (AM) and Weighted Arithmetic Mean (WAM) are introduced, described and compared to Choquet Integral (CI) approach which is a type of fuzzy measure used as a new method for MCDM. The comparisons are shown by evaluating and ranking software alternatives based on six main quality attributes as identified by the ISO 9126-1 standard. The evaluation experiments depend on real data collected from case studies

Adaptive neuro-fuzzy inference system for predicting alpha band power of EEG during muslim prayer (SALAT)

The features of electroencephalographic (EEG) signals include important information about the function of the brain. One of the most common EEG signal features is alpha wave, which is indicative of relaxation or mental inactivity. Until now, the analysis and the feature extraction procedures of these signals have not been well developed. This study presents a new approach based on an adaptive neuro-fuzzy inference system (ANFIS) for extracting and predicting the alpha power band of EEG signals during Muslim prayer (Salat). Proposed models can acquire information related to the alpha power variations during Salat from other physiological parameters such as heart rate variability (HRV) components, heart rate (HR), and respiration rate (RSP). The models were developed by systematically optimizing the initial ANFIS model parameters. Receiver operating characteristic (ROC) curves were performed to evaluate the performance of the optimized ANFIS models. Overall prediction accuracy of the proposed models were achieved of 94.39%, 92.89%, 93.62%, and 94.31% for the alpha power of electrodes positions at O1, O2, P3, and P4, respectively. These models demonstrated many advantages, including e±ciency, accuracy, and simplicity. Thus, ANFIS could be considered as a suitable tool for dealing with complex and nonlinear prediction problems.This research was supported and funded by the Prime Minister's Department, Malaysia (project no. 66-02-03- 0061/H-00000-3703), and University of Malaya, through a postgraduate grant (PS107-2010A)

Effect of Muslim Prayer (Salat) on a Electroencephalography and Its Relationship with Autonomic Nervous System Activity

Objectives: This study investigated the effect of Muslim prayer (salat) on the a relative power (RPa) of electroencephalography (EEG) and autonomic nervous activity and the relationship between them by using spectral analysis of EEG and heart rate variability (HRV). Methods: Thirty healthy Muslim men participated in the study. Their electrocardiograms and EEGs were continuously recorded before, during, and after salat practice with a computer-based data acquisition system (MP150, BIOPAC Systems Inc., Camino Goleta, California). Power spectral analysis was conducted to extract the RPa and HRV components. Results: During salat, a significant increase ( p < .05) was observed in the mean RPa in the occipital and parietal regions and in the normalized unit of high-frequency (nuHF) power of HRV (as a parasympathetic index). Meanwhile, the normalized unit of low-frequency (nuLF) power and LF/HF of HRV (as sympathetic indices) decreased according to HRV analyses. RPa showed a significant positive correlation in the occipital and parietal electrodes with nuHF and significant negative correlations with nuLF and LF/HF. Conclusions: During salat, parasympathetic activity increased and sympathetic activity decreased. Therefore, regular salat practices may help promote relaxation, minimize anxiety, and reduce cardiovascular risk.This research was supported and funded by the Prime Minister’s Department, Malaysia (project no. 66-02-03- 0061/H-00000-3703), and University of Malaya, through a postgraduate grant (PS107-2010A)