Damped perturbations in stellar systems: Genuine modes and Landau-damped waves

This research was stimulated by the recent studies of damping solutions in dynamically stable spherical stellar systems. Using the simplest model of the homogeneous stellar medium, we discuss nontrivial features of stellar systems. Taking them into account will make it possible to correctly interpret the results obtained earlier and will help to set up decisive numerical experiments in the future. In particular, we compare the initial value problem versus the eigenvalue problem. It turns out that in the unstable regime, the Landau-damped waves can be represented as a superposition of van Kampen modes plus a discrete damped mode, usually ignored in the stability study. This mode is a solution complex conjugate to the unstable Jeans mode. In contrast, the Landau-damped waves are not genuine modes: in modes, eigenfunctions depend on time as exp ( − iωt), while the waves do not have eigenfunctions on the real v-axis at all. However, ‘eigenfunctions’ on the complex v-contours do exist. Deviations from the Landau damping are common and can be due to singularities or cut-off of the initial perturbation above some fixed value in the velocity space.

Parfit on the Irrelevance of Deontological Distinctions

This chapter concerns Derek Parfit’s discussion in his On What Matters, volume 3 of the irrelevance of deontological distinctions. Parfit begins by expressing his concern that morality will be undermined because practical reason, which tells us all things considered what to do, will often conflict with what we consider to be morally right. Unlike Sidgwick, Parfit does not begin by identifying morality with a part of impartial practical reason but rather with what he considers common sense deontology. Also, unlike Sidgwick, he thinks it is clear that sometimes self-interest (which provides some reason even impartially considered) is overridden by (other) impartial practical reasons (e.g., there is decisive reason to give one’s penny to save millions of other people). This chapter first considers how Parfit thinks one’s practical reason should reconcile concerns about self-sacrifice, pursuing the greater good, and morality. It then considers his use of case-based reasoning to undermine moral principles embodying such distinctions as harming versus not aiding, harming as a mere means versus as a side effect, and redirecting threats (as in the Trolley Problem) versus starting new ones.

GAMBARAN WORK-LIFE BALANCE PADA JAKSA WANITA YANG TELAH BERKELUARGA

Married women who are working will encounter double roles. Participants in this study involve married female prosecutors having a family and children. Based on the initial interview with the participants, the prosecutors has a long responsibility starts from the investigation process with the police department, witness interrogation, case analysis and making the lawsuit, until the process of transferring the lawsuit to the court and convincing the judge with the lawsuit. Finally, the prosecutors also take an action in executing the criminals. They sometimes confront with the system problem versus their conscience which causes job stress and it influences on their family or they are on the conflict situation. However, there is also an enhancement situation; the job gives a positive advantage to the participants. The purpose of this study is to get the description of work-life balance on married female prosecutors having a family. The method used in this study is qualitative with the phenomenology approach of collecting data is by interview. There are 5 main themes in this study, such as job, family, experience of work-life balance, strategy and balance achievement. The result of this study shows that having double roles or experience of work-life balance, both participants experience similar conflict dynamics and enhancement orexperience ofwork-life balance. Both participants also make a perception that theyhave been in balance so far. They keep trying to be professional in working and also to spare their time be with their family. Keywords: Work-Life Balance, Conflict, Enhancement, Female Prosecutors, Married

Robust Waveform Design of Ultrasound Arrays for Medical Imaging

Sound speed is an effective parameter in designing an optimal beamformer. In conventional ultrasound imaging systems, the beamformer is designed assuming a fixed value of speed, whereas the speed in a tissue is not known precisely and also may fluctuate by a great value. The errors in estimating sound speed may lead to a severe degradation in the reconstructed image, as mainlobe width and sidelobe level of the beampattern are sensitive to the speed variations. In this paper, we consider the design of a transmit beamformer, which is robust to the speed variations. The problem is formulated as a convex optimization problem versus the covariance matrix of the excitation waveforms to obtain a beampattern with predefined mainlobe width and a minimum sidelobe level for all possible variations of speed. Then, by eigen-analysis of the obtained covariance matrix, a set of nonidentical single-carrier short-pulses for the excitation waveforms were designed. Various simulations indicate that the proposed method can yield a robust beampattern whose mainlobe width and sidelobe level almost remain constant by 10% speed variations. In contrast, the beampatterns obtained by nonrobust methods suffer extensive changes.

Coping and adjustment in caregivers: A systematic review

This systematic review assessed coping and adjustment in caregivers of all ages to provide a synthesis of existing literature in the context of methodological approaches and underlying theory. Four databases were searched. Reference lists, citations and experts were consulted. In total, 27 studies (13 quantitative and 14 qualitative) were included. Coping factors associated with adjustment (problem- versus emotion-focussed coping and cognitive strategies) and psychosocial factors associated with physiological adjustment (trait anxiety, coping style and social support) were identified. Results raised methodological issues. Future research requires physiological adjustment measures and longitudinal assessment of the long-term impact of childhood caregiving. Findings inform future caregiver research and interventions.

Reading Strategies in Persian and English Languages and Their Influence on English Reading Comprehension Ability

<p>The purpose of the present study is to investigate the relationship between successful readers’ strategies in Persian and English languages, and the impact of instruction of such strategies on English reading comprehension ability. The present study relies on Casanave’s (1998) expanded view of schema theory, the strategy schema, Goodman’s (1971) language transfer or linguistic independent hypothesis and Clarke’s idea of short-circuit or language ceiling hypothesis in ESL or EFL. This study also aims at finding an answer to the question of reading problem versus language problem, first raised by Alderson (1984, pp. 1-27) and then followed by Carrell (1991, pp. 159-179).</p>