2,968 research outputs found
Resilience of Locally Routed Network Flows: More Capacity is Not Always Better
In this paper, we are concerned with the resilience of locally routed network
flows with finite link capacities. In this setting, an external inflow is
injected to the so-called origin nodes. The total inflow arriving at each node
is routed locally such that none of the outgoing links are overloaded unless
the node receives an inflow greater than its total outgoing capacity. A link
irreversibly fails if it is overloaded or if there is no operational link in
its immediate downstream to carry its flow. For such systems, resilience is
defined as the minimum amount of reduction in the link capacities that would
result in the failure of all the outgoing links of an origin node. We show that
such networks do not necessarily become more resilient as additional capacity
is built in the network. Moreover, when the external inflow does not exceed the
network capacity, selective reductions of capacity at certain links can
actually help averting the cascading failures, without requiring any change in
the local routing policies. This is an attractive feature as it is often easier
in practice to reduce the available capacity of some critical links than to add
physical capacity or to alter routing policies, e.g., when such policies are
determined by social behavior, as in the case of road traffic networks. The
results can thus be used for real-time monitoring of distance-to-failure in
such networks and devising a feasible course of actions to avert systemic
failures.Comment: Accepted to the IEEE Conference on Decision and Control (CDC), 201
A Message Passing Strategy for Decentralized Connectivity Maintenance in Agent Removal
In a multi-agent system, agents coordinate to achieve global tasks through
local communications. Coordination usually requires sufficient information
flow, which is usually depicted by the connectivity of the communication
network. In a networked system, removal of some agents may cause a
disconnection. In order to maintain connectivity in agent removal, one can
design a robust network topology that tolerates a finite number of agent
losses, and/or develop a control strategy that recovers connectivity. This
paper proposes a decentralized control scheme based on a sequence of
replacements, each of which occurs between an agent and one of its immediate
neighbors. The replacements always end with an agent, whose relocation does not
cause a disconnection. We show that such an agent can be reached by a local
rule utilizing only some local information available in agents' immediate
neighborhoods. As such, the proposed message passing strategy guarantees the
connectivity maintenance in arbitrary agent removal. Furthermore, we
significantly improve the optimality of the proposed scheme by incorporating
-criticality (i.e. the criticality of an agent in its
-neighborhood).Comment: 9 pages, 9 figure
Orientasi Madrasah Dan Pengembangan Sumber Daya Manusia
For educational purposes can be achieved, then education should be managed by a professional educational institutions with good management and by staff who have high work motivation. To be able to answer the challenges of the future of the madrasa institution must have a human resources ready to face a future full of risks. Human Resource Management in Islamic educational institutions (Madrasah) toward the quality, is a must in order to improve the quality of education in madrasas. To be able to build a system of Islamic education (madrasah) of quality, the main key is to have skilled human resources (quality). To be able to have a reliable human resources, the madrasas must implement measures or strategies in managing and developing human resources degan good
Islam dalam Konteks Pengembangan Masyarakat Melayu Nelayan Bagian Pertama: Potret Kondisi Sosial Faktual Desa Tameran Bengkalis Riau
Temeran's fishing communities are mostly muslims malay. Tameran village has considerable potential of marine resources, but its people are still poor. The main focus of the study is a comprehensive study of the factual situation and social conditions, population, diversity of ethnic and religious groups, educational profile, system and community structure, management and management. The results of this research can be known that the Tameran villager has human resources with a formal education is still low. The Malay population who work as fishermen in the village of Tameran shares 187 people, consisting of: boat owner 18 people (9,6%), cano owner 42 people (22,5%), owner of pond 3 people (1,6%), As a fisherman laborer there are 80 people (42,8%) and others/working assistant of fisherman 44 people (23,5%). The community structure shows the pattern of "Patron-Client" condensed relationship with the coating system of the community: rich-poor, owner, the worker/worker of the fisherman. While organizational and social institutions are associated with the basic needs of human life
PREVALENCE, INTENSITY AND MANIFESTATION OF COVID-19 FEAR: A CROSS SECTIONAL ANALYSIS
Background: Pandemics are direct antecedent of distinctive physical, psychological, social and financial impacts. A large number of researches are being conducted regarding previous epidemics and pandemics and lot more is currently in progress vis-à-vis COVID-19. The current research is an attempt to explore psychological impacts of COVID-19 specifically to find out the existence, intensity and dynamics of COVID-19 fear in non-clinical educated population.
Subjects and methods: A cross sectional online study was conducted with non-clinical educated Pakistani citizens. Selfstructured questionnaire comprising close and open ended questions was used for data collection from different cities of Pakistan. N=317 participants (men=121, women=196) were the sample for this study. Demographic information was also sought. The age range of sample was 18 to 50+ years. Most of the participants fall in the category of age group 23-28 of sample. All the participants were educated from Intermediate till PhD but majority of participants had 16 years of education. SPSS 22 was used for quantitative data analysis. Qualitative data were analyzed using thematic analysis and content analysis.
Results: Results yield significant age wise and profession wise difference in existence of COVID fear. Nine major themes were extracted regarding nature of fear i.e. Corona Fear, Loss, fear of isolation or quarantine, religion related fear, death, consequences of COVID-19, Under developed country, Psychological component of fear and empathy. Those who denied fear were asked the reasons and six major themes were extracted here i.e Religion, Inevitability of death, Precautions, Belief in self, Myths or misinterpretation of disease and Avoidant approach.
Conclusions: Age and profession significantly influenced fear of COVID-19. Gender-wise exploration of themes yields interesting insights. Participants reflected positivity and empathy in crisis situation
Aiding GPS with Additional Satellite Navigation Services
In modern warfare navigation services are very important. GPS is currently providing service for accurate navigation, except in some areas, especially urban areas, where GPS signals cannot always be tracked by users. In these cases some additional navigation support could be provided by other global navigation satellite systems. If GPS is combined with other navigation systems than the navigation gap will be minor. In this thesis, the effect of combining GPS with other satellite navigation systems, specifically GLONASS, Galileo and Compass, is evaluated in terms of availability and position dilution of precision (PDOP) values. First, satellite constellations are simulated in Satellite Tool Kit (STK) to generate ephemeris data. A street scenario is then established for simulating different elevation mask angles to represent urban and mountainous areas. The performance of the combined system is also evaluated as a function of the uncertainty in the time offset between systems. Combined GPS/GLONASS and GPS/Compass solutions showed little improvement for low elevation mask angles, however they provided some enhancement for higher elevation angles. Combined GPS/Galileo performance was improved for all elevation angles compared to only GPS, GPS/GLONASS, and GPS/Compass. The best results for availability and PDOP were obtained from combining all four systems. Although using satellites from other constellations enhances availability and decreases errors. It also brings dependency on other systems other than GPS. Adding two satellites from only the Galileo constellation to GPS is shown to be a configuration with a good compromise between dependency and performance
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