Constant-Factor FPT Approximation for Capacitated k-Median

Capacitated k-median is one of the few outstanding optimization problems for which the existence of a polynomial time constant factor approximation algorithm remains an open problem. In a series of recent papers algorithms producing solutions violating either the number of facilities or the capacity by a multiplicative factor were obtained. However, to produce solutions without violations appears to be hard and potentially requires different algorithmic techniques. Notably, if parameterized by the number of facilities k, the problem is also W[2] hard, making the existence of an exact FPT algorithm unlikely. In this work we provide an FPT-time constant factor approximation algorithm preserving both cardinality and capacity of the facilities. The algorithm runs in time 2^O(k log k) n^O(1) and achieves an approximation ratio of 7+epsilon

Autonom fahrendes Vehikel: Bericht zum Projekt des Lego Mindstorms Seminars

Die n¨achste Generation des Fahrens nach den Elektrofahrzeugen geh¨ort dem autonomen Fahren. So sagte einst: Elon Musk, der Pionier des autonomen Fahrens: ”In 20 Jahren wird sich der Besitz eines Autos, das nicht autonom f¨ahrt, anf¨uhlen wie heute der Besitz eines Pferdes.“ [1] Immer mehr große Automobilunternehmen forschen und investieren in diesem Bereich. Da dieses Thema in der Gesellschaft derzeit heiß diskutiert wird und es immer noch Bedarf in Sachen Forschung und Sicherheit gibt, besch¨aftigt sich dieses Projekt mit dem selbst¨andigen Fahren am Vorbild des ”EZ10“ der Deutschen Bahn. Heutige Entwicklungen, im Bereich autonomes Fahren, zeigen einen neuen Trend auf. Unternehmen setzen darauf die  modernen Autos mit Assistenz-Systemen auszustatten, wie zum Beispiel dem Lenk-Assistenten, um den Straßenverkehr sicherer zu gestalten, gleichzeitig aber auch dem Menschen die Fahrt so angenehm wie m¨oglich zu machen. Des Weiterenkommt die priorisierte Entwicklung der Elektrofahrzeuge f¨ur ein umweltbewusstes Fahren dazu. Mit ”Lego Mindstorms“ wird im folgenden Beitrag ein Einstieg in das breite Spektrum der Elektromobilit¨at beschrieben. Ziel dieses Projektes ist: Grundlagen zu erarbeiten im Rahmen der M¨oglichkeiten von ”Lego NXT“ mit geringer und kosten günstiger Hardware-Ausstattung. Dabei werden wichtige Funktionen des Roboters beschrieben und erkl¨art. Außerdem werden wesentliche Ergebnisse dargestellt und diskutiert. Anschließend wird ein Ausblick ¨uber m¨ogliche Entwicklungen in der Zukunft und Verbesserungen gegeben. Bei dem Lego Mindstorms Projekt wurden zuerst Grundkenntnisse in Matlab vermittelt. Dies  geschah in den ersten drei Tagen. Anschließend wurde eine Idee eines Roboters entwickelt und vor der Seminargruppe vorgestellt in Form eines Kurzvortrages mit Powerpointpr¨asentation. In den darauf folgenden Tagen ist durch  Arbeitsaufteilung ein Roboter gebaut und programmiert wurden. Dabei ist der Roboter durch viele Testl¨aufe optimiert und U¨ berarbeitungen im Quellcode angepasst wurden. Schließlich kam ein funktionsf¨ahiger Roboter heraus, der den Projektleitern und der Seminargruppe pr¨asentiert werden konnte

The level of fundamental qualities of somatic structure and physical fitness of young classical dancers in comparison to their peers practising acrobatic gymnastics – a comparative analysis

Classical (academic) dance, colloquially called ballet, is associated with subtlety and incredible grace of movement. Despite the fact that there has been ages from the creation of ballet, the undoubted beauty and airiness of the forms presented by the dancers make ballet still very popular throughout the world. Ballet is a kind of theatrical show with such fundamental elements as music, choreography and movement. Considering a ballet performance (obviously in a great simplification) and analysing it solely and exclusively within the aforementioned elements, it may be assumed that there is a parallel between the elements of classical dance and an acrobatic routine presented during competitions. Music, choreography and movement are essential in acrobatics as well. The aim of this study is to compare the level of somatic qualities (body height and weight) and the characteristics of fundamental qualities of physical fitness (agility, strength, flexibility, liveliness) of ballet dancers, as well as presenting their results in comparison to dancers’ peers practising acrobatic gymnastics. The results of the analysis indicate that dancers are significantly taller than acrobats also when compared to the standards described in Drozdowski’s „Dzieci Polski Zachodniej”. The adopted assumption of a lower level of general physical fitness of classical dancers in comparison to acrobats has been confirmed. At the same time, in an attempt to measure the flexibility of the body, a statistical difference has been observed within a group of 12-year old girls only

The assessment of changes of the results in the 30-second chair stand and 8-foot up-and-go tests within women over the age of sixty, participating in the gymnastics class. A pilot study

The ageing process leads to irreversible changes within the functioning of the whole human organism. One of the problems which the seniors have to face is sarcopenia, that is a progressive loss of the skeletal muscles mass, which results in the loss of strength. Regularly performed physical exercises may significantly slow down this process and even cause muscle hypertrophy. A 13-week programme of the shaping gymnastic exercises has been drawn up to improve the strength of the lower body muscles. 25 women aged 60–81 took part in this programme. Strength of the lower limbs and dynamic agility have been assessed relying on the 30-second chair stand and 8-foot up-and-go Fullerton tests. The results of the statistical analysis indicate the growth of strength of the lower muscles on average by 24% and the dynamic agility by 6%. The improved muscle persistence has also been observed – at the end of the cycle of research the group has achieved better results in the post-workout attempts than in the pre-workout ones. The shaping gymnastic exercises regularly performed by women over the age of sixty improve the strength of lower limb muscles, dynamic agility and muscle persistence

Role of exercise and tools used in physical activities with the elderly

In recent years there has been an increased interest in forms of activities among older people. Regular physical exercise performed by seniors slow down the aging process, extend the period of physical and mental fitness. Regular physical activity is one way to counteract adverse processes of involution. To prevent involution situations, gymnastic, movement, dance, athletics, swimming, or related to other sports exercise can be used. The study shows the importance of some forms of physical activities for people in old age, and presented examples of exercises and tools used in physical activities with the elderly

ANALYSIS OF VIBRATIONS GENERATED BY THE MULTI-BODY MODEL OF A PLANETARY GEAR

In the paper the dynamic model of an one-stage planetary gear was presented. The model was developed on the basis of a multi-body dynamics method. To conduct dynamic simulations the specialized multi-body dynamics software was used. In the study the tests results for steady state operations of the planetary gear were presented. In the paper the meshing force signals were analyzed. The vibrations generated by the model consist of carrier and gear meshing frequency harmonics. On the spectra the amplitude modulations of the gear meshing frequencies harmonics were observed

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Investigating Risk Factors for Complications after Ileostomy Reversal in Low Anterior Rectal Resection Patients : an Observational Study

: Introduction: Defunctioning ileostomy has been widely used in patients undergoing low anterior rectal resection to reduce the rate of postoperative leakage. It is still not clear whether interval between primary procedure and ileostomy reversal has an impact on treatment outcomes. Methods: In our prospective observational study we reviewed 164 consecutive cases of patients who underwent total mesorectal excision with primary anastomosis. Univariate and multivariate regression models were used to search for risk factors for prolonged length of stay and complications after defunctioning ileostomy reversal. Receiver operating characteristic curves were utilized to set cut-off points for prolonged length of stay and perioperative morbidity. Results: In total, 132 patients were included in the statistical analysis. The median interval between primary procedure and defunctioning ileostomy reversal was 134 (range: 17–754) days, while median length of stay was 5 days (4–6 interquartile range (IQR)). Prolonged length of stay cut-off was established at 6 days. Regression models revealed that interval between primary surgery and stoma closure as well as complications after primary procedure are risk factors for complications after defunctioning ileostomy reversal. Prolonged length of stay has been found to be related primarily to interval between primary surgery and stoma closure. Conclusions: In our study interval between primary surgery and stoma closure along with complication occurrence after primary procedure are risk factors for perioperative morbidity and prolonged length of stay (LOS) after ileostomy reversal. The effort should be made to minimize the interval to ileostomy reversal. However, randomized studies are necessary to avoid the bias which appears in this observational study and confirm our findings