Resource allocation for transmit hybrid beamforming in decoupled millimeter wave multiuser-MIMO downlink

This paper presents a study on joint radio resource allocation and hybrid precoding in multicarrier massive multiple-input multiple-output communications for 5G cellular networks. In this paper, we present the resource allocation algorithm to maximize the proportional fairness (PF) spectral efficiency under the per subchannel power and the beamforming rank constraints. Two heuristic algorithms are designed. The proportional fairness hybrid beamforming algorithm provides the transmit precoder with a proportional fair spectral efficiency among users for the desired number of radio-frequency (RF) chains. Then, we transform the number of RF chains or rank constrained optimization problem into convex semidefinite programming (SDP) problem, which can be solved by standard techniques. Inspired by the formulated convex SDP problem, a low-complexity, two-step, PF-relaxed optimization algorithm has been provided for the formulated convex optimization problem. Simulation results show that the proposed suboptimal solution to the relaxed optimization problem is near-optimal for the signal-to-noise ratio SNR <= 10 dB and has a performance gap not greater than 2.33 b/s/Hz within the SNR range 0-25 dB. It also outperforms the maximum throughput and PF-based hybrid beamforming schemes for sum spectral efficiency, individual spectral efficiency, and fairness index

For Want of Resources: Reimagining the State's Obligation to Use 'Maximum Available Resources' for the Progressive Realisation of Economic, Social and Cultural Rights

This thesis provides insights into, additional commentary on and analysis of the fundamental role of resources in advancing Economic, Social and Cultural Rights (ESC rights). Its objective is to expand the policy space within which States can operate to fulfil their obligations related to these rights. It addresses a number of central questions about the resource dimension of ESC rights policy, including interpretation of the concept of ‘maximum available resources’ in the context of the International Covenant on Economic, Social and Cultural Rights (ICESCR). By applying a cross-disciplinary approach, the thesis investigates legal, economic and public policy dimensions of resource mobilisation, allocation and governance that are essential in advancing progressive realisation of ESC rights. This thesis proposes that the obligation to take steps to the ‘maximum available resources’ for the progressive realisation of ESC rights can be made more meaningful by adopting a broader interpretation of the concept of resources and by taking active steps to maximise the quality and quantity of resources available through public sector revenue, international assistance and co-operation and private sector investment, all of which can be enhanced through institutional mechanisms and processes of allocation and governance. This proposition is supported by an in-depth qualitative analysis of relevant ESC rights literature, interpretive works of the ESCR Committee and Special Rapporteurs, periodic reports of States, institutional documents and case studies, which provide evidence on the current understanding and application of the concept of resources in this context. Based on analysis of multiple sources of evidence on State practice, this thesis presents a cross-disciplinary model of the nature, scope and policy dimensions of resources for ESC rights and suggests how concerted State policy efforts can optimise their impact on the realisation of ESC rights

Sensitivity analysis approach for robust probabilistic risk assessment

The main objective of this investigation is to develop a robust and simplified Probabilistic Risk Assessment (PRA) approach specifically oriented to produce results for risk management decisions of high technology systems. The techniques are based on defining a set of three Significant Indices which quantify the importance of each component, and hence develop a ranking of the components, both with respect to the mean and variance, in the fault tree/event tree structure. The variations in the Top Event probability distribution upon the variations in the component input probability distributions are also evaluated, as well as the first and second moments of the Top event;A method is devised to analyze the sensitivity of the component-ranking upon the basic event probability distribution model. If the new set of Significance Indices, developed as a result of the sensitivity analysis, do not warrant a substantial change in the ranking of the components, then the PRA results are defined here as robust. An important feature of the Significance Indices, and hence the robustness of the PRA results, is the convenience of finding the mean and variance of the Top event due to single or multiple variations in the mean and variance of one or more basic events in the system model

The Taylor Rule and the Macroeconomic Performance in Pakistan

A widely agreed proposition in modern economics is that policy rules have greater advantage over discretion in improving economic performance. Simple monetary policy instrument rules are feasible options for developing countries lacking the pre-requisites for more sophisticated targeting rules. Notwithstanding the focus of modern literature on the issue, the State Bank of Pakistan (SBP) has never declared itself to be following any type of rule. Surprisingly, this topic has remained out of research focus (among the academia and the practitioners) in Pakistan. This is the first attempt to deal with a rulebased monetary policy strategy in the case of the SBP. We have estimated the Taylor rule and simulated the economy using this rule as a monetary policy strategy. Our results indicate that the SBP has not been following the Taylor rule. In fact, the actual policy can be taken as an extreme deviation from it. On the other hand, counterfactual simulation confirms that macroeconomic performance can be improved, in terms of stability in inflation and output, when a simple Taylor rule is adopted. In this regard the parameter values (especially the inflation target) in the rule must be set according to the conditions of the economy under consideration rather than by relying on the ones suggested by the Taylor rule.Taylor Rule, Macroeconomic Performance, Counterfactual Simulation

The Taylor Rule and the Macroeconomic Performance in Pakistan

A widely agreed proposition in modern economics is that policy rules have greater advantage over discretion in improving economic performance. Simple monetary policy instrument rules are feasible options for developing countries lacking the pre-requisites for more sophisticated targeting rules. Notwithstanding the focus of modern literature on the issue, the State Bank of Pakistan (SBP) has never declared itself to be following any type of rule. Surprisingly, this topic has remained out of research focus (among the academia and the practitioners) in Pakistan. This is the first attempt to deal with a rule-based monetary policy strategy in the case of the SBP. We have estimated the Taylor rule and simulated the economy using this rule as a monetary policy strategy. Our results indicate that the SBP has not been following the Taylor rule. In fact, the actual policy can be taken as an extreme deviation from it. On the other hand, counterfactual simulation confirms that macroeconomic performance can be improved, in terms of stability in inflation and output, when a simple Taylor rule is adopted. In this regard the parameter values (especially the inflation target) in the rule must be set according to the conditions of the economy under consideration rather than by relying on the ones suggested by the Taylor rule.Taylor Rule, Macroeconomic Performance, Counterfactual Simulation

Management of the Primary Tumor in Metastatic Colorectal Cancer

Background Systemic therapy is the mainstay of treatment for stage IV colorectal cancer (CRC) and provides meaningful survival benefit. Currently, there is very low quality evidence available regarding benefit of primary tumor resection in patients with metastatic CRC. In spite of uncertain survival benefit, high rates of surgical resection have been reported in patients with unresectable metastatic disease. There is a lack of randomized clinical trial to address this important question in patients with stage IV CRC. Although several observational studies have suggested potential survival benefit of primary tumor resection, lack of randomization and failure to control important prognostic variables such as performance status, are major critiques to the findings of the observational studies. We have undertaken this large population-based cohort study to determine the survival benefit of primary tumor resection in stage IV CRC by minimizing various biases reported in the literature. Hypothesis We hypothesized that primary tumor resection in patients with stage IV CRC improves survival independent of chemotherapy and other known prognostic variables. Objectives To systematically review the published literature and synthesize the data in relation to primary tumor resection in stage IV CRC. To compare survival of patients with stage IV CRC who underwent primary tumor resection with the patients who did not have surgery and to determine the prognostic importance of surgery of the primary tumor in stage IV CRC. To determine survival advantage of primary tumor resection in patients with stage IV CRC and minimally symptomatic or asymptomatic primary tumor. To determine survival advantage of primary tumor resection in patients with stage IV CRC during the period of modern chemotherapy. Methods The study was conducted in two phases. During the first phase, a systematic review of published literature was performed using the Medline, EMBASE and CENTRAL databases. Studies were selected by using pre-specified eligibility criteria with restriction to publication dates from 1980 onward, English language, and human studies. Articles that met the inclusion criteria were assessed for quality by using the Ottawa-Newcastle score & GRADE. Data was collected and synthesized as per the PRISMA guideline. In the second phase, population-based retrospective cohort studies were performed. The study population was comprised of patients with stage IV CRC diagnosed during the period of January 1992 to December 2010 in the province of Saskatchewan, Canada. The prognostic significance of primary tumor resection was initially evaluated in patients’ cohort with stage IV CRC diagnosed during 1992-2005 period. The results were validated in a second patients cohort diagnosed during 2006-2010. Survival was calculated using the Kaplan-Meier method. Survival distributions of different groups were compared by the log-rank tests. Cox proportional multivariate regression analyses were performed to determine survival benefit of primary tumor resection by controlling the other prognostic variables. Results Systematic review: Of total of 3379 reports, 15 retrospective observational studies were selected. Of total 12456 patients, 8620 (69%) underwent primary tumor resection. Median overall survival of the resection group was 15.2 months (range: 10-30.7) compared with 11.4 months (range: 3-22) in the non-resection group. Hazard ratio (HR) for survival was 0.69 (95% CI: 0.61-0.79), which favors surgical resection. Mean postoperative mortality and nonfatal complications rates were 4.9% (95% CI: 0-9.7) and 25.9% (95% CI: 20.1-31.6), respectively. Cohort Studies: A total 1378 eligible patients were identified during the period of 1992-2005. Nine hundred and forty-four (68.5%) underwent primary tumor resection. Among 1378 patients, 42.3% received chemotherapy. Cox proportional analyses revealed that use of chemotherapy (HR 0.47, 95% CI: 0.41-0.54), primary tumor resection (HR 0.49, 95% CI: 0.41-0.58), second-line chemotherapy (0.47, 95% CI: 0.45-0.64), and metastasectomy (HR 0.54, 95% CI: 0.45-0.64) were correlated with superior survival. In a subcohort of 834 patients with asymptomatic or minimally symptomatic disease, primary tumor resection was correlated with better survival (HR 0.47; 0.39-0.57). Test for interaction between ≥1 metastatic sites and surgery was significant suggesting a larger benefit of surgery in patients with stage IVa disease. These findings were validated in a cohort of 569 patients with stage IV CRC diagnosed during the period of 2006-2010. Fifty seven percent patients received chemotherapy and 91.4% received modern chemotherapy. Median overall survival of patients who received all active agents and underwent primary tumor resection was 39 months (95% CI: 25.1-52.9). In multivariate analysis, primary tumor resection, hazard ratio (HR):0.44 (95% CI: 0.35-0.56), was correlated with superior survival. Conclusions Our study supports primary tumor resection in patients with stage IV CRC. It correlates with better survival independent of known prognostic variables such as chemotherapy, metastasectomy, performance status and comorbid illness. In a subgroup of asymptomatic or minimally symptomatic patients or who were treated with modern chemotherapy and biologics, primary tumor resection was correlated with better survival