The paper addresses the problem of constrained pole placement in discrete-time linear systems. The design conditions are outlined in terms of linear matrix inequalities for the Dstable ellipse region in the complex Z plain. In addition, it is demonstrated that the D-stable circle region formulation is the special case of by this way formulated and solved pole placement problem. The proposed principle is enhanced for discrete-lime linear systems with polytopic uncertainties.
Asma Jahangir, the prominent Pakistani lawyer and human rights activist, who had received several awards for her courageous work, passed away on February 11, 2018. Her untimely death at the age of 66 was mourned by a wide public, not only in Pakistan. The newspaper obituaries particularly highlighted her accomplishments and campaigns on behalf of women, children, religious minorities, poor and disenfranchised communities. The deceased “voice of the voiceless” is probably best known for her advocacy on the rights of the most vulnerable and disempowered sections of society and her uncompromising commitment to democratic principles. However, another aspect of Asma Jahangir’s legacy, her thoughts and insights on political power mechanisms in Pakistan and beyond, has so far been rather neglected. With her long-term experience as a lawyer, an activist, and a UN Special Rapporteur, Asma Jahangir often offered useful reflections on the main causes of human rights abuses in Pakistan and the neighbouring countries. Among other things, she pointed to the detrimental effects of the politics of sectarianization and securitization, and also stressed the ongoing aspiration of a great part of the population in the global South to live a dignified life. On the basis of selected publications, reports, and interviews, this paper will provide a number of Asma Jahangir’s explanations for national, regional, and international shortcomings and structural problems (fragile democracies, undermined rule of law; the influence of militant non-state actors; regional/international interconnections and constraints, etc.) which remain relevant under the current conditions.
The article is a follow-up and an extension to previously published papers by HolzerŻelażewska & Holzer (1997) and Holzer-Żelażewska & Tymicki (2009). Fristly, we have added new cohorts to the cohort analysis based on the individual data from births registration for the years 2009–2015. Secondly, we have extended the scope of the study by taking into account the context of postponement and recuperation to analyses of cohort fertility of Polish women.
The approach applied to the fertility postponement and recuperation on the cohort data refers to the method which was originally proposed by Frejka (2011) and Lesthaeghe (2001) and further developed by Sobotka et al. (Sobotka et al., 2011). This method allows for calculation of fertility postponement and recuperation measures with respect to a benchmark cohort chosen as the one that first experiences an onset of the increase in the mean age of motherhood at first birth.
The results show the remarkable changes in the fertility patterns in Poland. The main driving forces behind the change in fertility patterns in Poland are related to the postponement of first births along with a relatively good recuperation. The magnitude of recuperation for Polish cohorts dropped significantly for second births and was almost non-existent for third and higher births. Therefore, the pattern of fertility in Poland observed till 2015 could be characterized by postponement and recuperation of first births along with a significant decrease in second births with perpetual postponement of third and higher births.
The paper presents kinematic characteristics of the double 4-link coupler system, used in actual powertrain of low-floor trams (NGT6-Kr). The spatial kinematic model of the couplings was formulated assuming ideal joints and rigid members. The constraints equations of the mechanism were solved iteratively and differentiated to obtain the Jacobian matrix. The mobility and singularity analysis of the coupler mechanism was performed on the basis of the Jacobian matrix.
Kinematic characteristics of the single and double coupler system were analyzed for gross angular and linear axle displacements (misalignments), taking the advantage of the fully nonlinear model. The coupling system was evaluated based on criteria describing homokinetics, balancing and clearance demands, and angular displacements in the joints. These criteria were determined for different design parameters like: coupler proportions, platform shift and angle, middle shaft length.