scholarly journals Rational quartic spectrahedra

2021 ◽  
Vol 127 (1) ◽  
pp. 79-99
Author(s):  
Martin Helsø ◽  
Kristian Ranestad

Rational quartic spectrahedra in $3$-space are semialgebraic convex subsets in $\mathbb{R} ^3$ of semidefinite, real symmetric $(4 \times 4)$-matrices, whose boundary admits a rational parameterization. The Zariski closure in $\mathbb{C}\mathbb{P} ^3$ of the boundary of a rational spectrahedron is a rational complex symmetroid. We give necessary conditions on the configurations of singularities of the corresponding real symmetroids in $\mathbb{R} \mathbb{P} ^3$ of rational quartic spectrahedra. We provide an almost exhaustive list of examples realizing the configurations, and conjecture that the missing example does not occur.

Author(s):  
Ольга Николаевна Мазеина ◽  
Антон Михайлович Лысухин

В статье рассматриваются актуальные проблемы применения огнестрельного оружия сотрудниками подразделений охраны Федеральной службы исполнения наказаний. Обозначены нормативно-правовые акты, которые наделяют сотрудников правом применять различные меры принуждения к правонарушителям и освещают ситуации, в которых возможно использование и применение огнестрельного оружия. Юридическим основанием возникновения обязанности своевременно и правомерно использовать огнестрельное оружие в целях устранить источники опасности для сотрудников определяется реальная угроза. В статье рассматриваются вопросы, касающиеся особенностей несения службы: сложности, напряженности, экстремальности, динамичности, непредсказуемости оперативной обстановки. При этом акцентируется внимание на готовности сотрудников к качественному несению службы, способности применить оружие в необходимых условиях - условиях реальной угрозы, исходящей от исчерпывающего перечня источников опасности, непосредственно угрожающих жизни и здоровью. Основными проблемами применения огнестрельного оружия сотрудниками подразделений охраны представлены: превышение пределов правомерного применения; необходимость доказывания законности применения оружия в следственных органах и судах; страх применения огнестрельного оружия; неготовность сотрудников к применению оружия в отношении людей; дефицит времени, связанный с принятием решения о применении оружия; профессионально значимые качества сотрудников и др. Предложены меры и мероприятия по повышению надежности и эффективности служебной деятельности, четкого выполнения поставленных задач, правовой защищенности сотрудников, несущих службу с оружием. The article deals with the actual problems of using firearms by employees of security units of the Federal penitentiary service of Russia. The authors of the article indicate the legal acts that give employees the right to apply various coercive measures to offenders and highlight the situations in which the use and use of firearms is possible. The legal basis for the obligation to use firearms in a timely and lawful manner in order to eliminate sources of danger for employees is determined by the real threat. The article deals with issues related to the peculiarities of service: complexity, tension, extremity, dynamism, and unpredictability of the operational situation. At the same time, attention is focused on the readiness of employees for high - quality service, the ability to use weapons in the necessary conditions-conditions of a real threat emanating from an exhaustive list of sources of danger that directly threaten life and health. The main problems with the use of firearms by employees of security units are: exceeding the limits of lawful use; the need to prove the legality of the use of weapons in investigative bodies and courts; fear of the use of firearms; lack of readiness of employees to use weapons against people; lack of time associated with making a decision on the use of weapons; professionally significant qualities of employees, etc.the Authors suggest measures and measures to improve the reliability and efficiency of official activities, clear performance of tasks, legal protection of employees serving with weapons.


2020 ◽  
Vol 5 (1) ◽  
pp. 88-96
Author(s):  
Mary R. T. Kennedy

Purpose The purpose of this clinical focus article is to provide speech-language pathologists with a brief update of the evidence that provides possible explanations for our experiences while coaching college students with traumatic brain injury (TBI). Method The narrative text provides readers with lessons we learned as speech-language pathologists functioning as cognitive coaches to college students with TBI. This is not meant to be an exhaustive list, but rather to consider the recent scientific evidence that will help our understanding of how best to coach these college students. Conclusion Four lessons are described. Lesson 1 focuses on the value of self-reported responses to surveys, questionnaires, and interviews. Lesson 2 addresses the use of immediate/proximal goals as leverage for students to update their sense of self and how their abilities and disabilities may alter their more distal goals. Lesson 3 reminds us that teamwork is necessary to address the complex issues facing these students, which include their developmental stage, the sudden onset of trauma to the brain, and having to navigate going to college with a TBI. Lesson 4 focuses on the need for college students with TBI to learn how to self-advocate with instructors, family, and peers.


Methodology ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 104-112 ◽  
Author(s):  
Rachel Vis-Visschers ◽  
Vivian Meertens

We used the Cognitive Interviewing Reporting Framework (CIRF) to restructure the report of a pretest on a European health survey questionnaire. This pretest was conducted by the Questionnaire Laboratory of Statistics Netherlands, and the original report was written according to a standard Statistics Netherlands format for pretesting reports. This article contains the rewritten report with highlights from the case study. The authors reflect on the process of rewriting and the usefulness of the CIRF. We conclude that expanded use of the CIRF as a reporting format for articles on cognitive pretests would enhance international comparability, completeness, and uniformity of research designs, terminology, and reporting. A limitation of the CIRF is that it does not provide an exhaustive list of items that could be included in a report, but it is more a “minimal standard”: that is a report on how a cognitive pretest was conducted should at least contain a description of the CIRF items.


2000 ◽  
Vol 5 ◽  
pp. 77-89 ◽  
Author(s):  
M. Kazakevičiūtė ◽  
R. Krasauskas

There is reviewed the construction of a rational blending surface between cylinders and cones in some interlocation cases. This surface is constructed as a patch of rolling ball envelope, i.e. as a patch of tangent canal surface of rational-variable radius. This construction defines rational parameterization of a blending surface. The constructed surface is Laguerre invariant.


Author(s):  
František Čapka

AbstractThis study focuses on the process of the gradual shaping of Czech national awareness in Moravia from the beginning of the nineteenth century onwards when the necessary conditions for the development of improved mutual relations between the Czech (Slavic) population in the two Lands of the Czech Crown -Bohemia and Moravia - were slowly being formed. Moravia faced a number of handicaps to the development of a national revival in comparison with Bohemia, the most significant of which was the relatively high degree of Germanisation of the land. A change to the image of Moravia came in the revolutionary years 1848/1849, when Czech national awareness spread to broader sections of society in Moravia. The view of Bohemia held by the Moravians underwent significant change and a period of increasingly intensive political and cultural contact between the two lands arose.


2020 ◽  
Vol 7 (3) ◽  
pp. 89-96
Author(s):  
Dilbar Karshieva ◽  

This article demonstrates the great attention and care paid by the state to the military and their families in our country.Social protection of families of military men consists in creating necessary conditions for family members to develop and demonstrate their abilities in socio-economic, cultural, medical and other spheres.


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