Flexible Scheduling and Control of Bandwidth and In-transit Services for End-to-End Application Workflows

Author(s):  
Mehmet Fatih Aktas ◽  
Georgiana Haldeman ◽  
Manish Parashar
2017 ◽  
Vol 7 (3) ◽  
pp. 174
Author(s):  
AmirNezam Barati ◽  
Ali Babayee Mehr ◽  
Mohsen Sharifi

Combating against corruption is one of the most important factors for establishing Good Governance. Corruption is a social, political and economic phenomenon that defect the democratic institutions and stop establishing good governance. This study using analytical – descriptive, analyses the role of civil society in combat corruption with glance to I.R.IFindings of this study show that the role of special civil societies has remarkable efficiency and effectiveness in combat corruption. In challenging corruption different actor such as government, private sector and specialized civil society have function, but the role of civil societies is more effective than others.In relating to the I.R.I actions against corruption, the country enacted different laws such as the law of access to information, the Law of United Nations Convention against Corruption and this process will send a clear message that the country is determined to prevent and control corruption. In pathology of corruption in I.R of Iran the concentration on fighting against corruption, is concentrated on "The Staff of Combat against Economic Corruption" and civil society don’t have effective or remarkable role to fight against this abnormality and this Staff is most important centers to harmonize the actions against corruption. Finally, the most important causes of corruption in every developing Nations in Transit such as Iran are big government and interference of Government in economy, the weakly embedded rule of law, the ineffective and inefficient of government policy, lack of accountability and institutional transparency.


2021 ◽  
Author(s):  
◽  
Caleb Gordon

<p>In measurement and control systems there is often a need to synchronise distributed clocks. Traditionally, synchronisation has been achieved using a dedicated medium to convey time information, typically using the IRIG-B serial protocol. The precision time protocol (IEEE 1588) has been designed as an improvement to current methods of synchronisation within a distributed network of devices. IEEE 1588 is a message based protocol that can be implemented across packet based networks including, but not limited to, Ethernet. Standard Ethernet switches introduce a variable delay to packets that inhibits path delay measurements. Transparent switches have been introduced to measure and adjust for packet delay, thus removing the negative effects that these variations cause.  This thesis describes the hardware and firmware design of an IEEE 1588 transparent end-to-end Ethernet switch for Tekron International Ltd based in Lower Hutt, New Zealand. This switch has the ability to monitor all Ethernet traffic, identify IEEE 1588 timing packets, measure the delay that these packets experience while passing through the switch, and account for this delay by adjusting a time-interval field of the packet as it is leaving the switch. This process takes place at the operational speed of the port, and without introducing significant delay. Time-interval measurements can be made using a high-precision timestamp unit with a resolution of 1 ns. The total jitter introduced by this measurement process is just 4.5 ns through a single switch.</p>


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bowen Hou ◽  
Shuzhi Zhao ◽  
Huasheng Liu ◽  
Jin Li

Traditional transit systems are susceptible to unexpected costs and delays due to unforeseen events, such as vehicle breakdowns. The randomness of these events gives the appearance of an imbalance in the number of operating vehicles and of unreliable transit services. Therefore, this paper proposes the queueing theory as a means to characterize the state of any given transit system considering the risk of vehicle breakdowns. In addition, the proposed method is used to create an optimized model for reserve fleet sizes in transit systems, in order to ensure the reliability of the transit system and minimize the total cost of any transit system exposed to the risks of vehicle breakdowns. The optimization is conducted based on the two main characteristics of all bus systems, namely, operator costs and user costs, in both normal and disruptive situations. In addition, the situations in our optimization are generated in scenarios that have a certain degree of probability of experiencing delays. This paper formulates such an optimization model, presents the formulation solution method, and proves the validity of the proposed method.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiongfei Lai ◽  
Jing Teng ◽  
Paul Schonfeld ◽  
Lu Ling

Providing convenient transit services at reasonable cost is important for transit agencies. Timed transfers that schedule vehicles from various routes to arrive at some transfer stations simultaneously (or nearly so) can significantly reduce wait times in transit networks, while stochastic passenger flows and complex operating environments may reduce this improvement. Although transit priority methods have been applied in some high-density cities, operating delays may cause priority failures. This paper proposes a resilient schedule coordination method for a bus transit corridor, which analyzes link travel time, passenger loading delay, and priority signal intersection delay. It maximizes resilience based on realistic passenger flow volume, whether or not transit priority is provided. The data accuracy and result validity are improved with automatically collected data from multiple bus routes in a corridor. The Yan’an Road transit corridor in Shanghai is used as a case study. The results show that the proposed method can increase the system resilience by balancing operation cost and passenger-based cost. It also provides a guideline for realistic bus schedule coordination.


2018 ◽  
Vol 7 (S1) ◽  
pp. 123-129
Author(s):  
K. Kavitha

A Mobile Ad hoc NETwork (MANET) is a collection of wireless nodes communicating with each other in the absence of any infrastructure. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet. In this paper, we compare the performance of On-Demand Multicast Routing Protocol (ODMRP), Adaptive demand driven Multicast Routing Protocol (ADMR) With Efficient Geographic Multicast Routing Protocol (EGMP) under different mobility models such as Random Way Point Model, Manhattan Model and Random Drunken Model. Using these models, performance metrics such as Packet Delivery Ratio, End-to-End Delay and Control Overhead are evaluated. ODMRP dynamically builds the route and manages the group membership. In ADMR, Multicast routing state is dynamically established and maintained only for active groups and only in nodes located between multicast senders and receivers. ADMR detects the high mobility without the use of GPS or other positioning system. EGMP supports a zone-based scheme to efficiently handle the two-tier membership management, and takes advantage of the membership management structure to efficiently track the locations of all the group members. The simulation result shows that the throughput of ADMR is higher than that of ODMRP and EGMP at high mobility and EGMP is high at low mobility. End to end delay and control overhead of EGMP is higher than that of ODMRP and ADMR.


Author(s):  
Zhong-Ren Peng ◽  
Sarah Hawks ◽  
Kate West

Many U.S. transit agencies have been using planning support software to assist in daily planning, operation, and customer services. However, the literature is not clear about the extent to which transit agencies are using planning support software programs for daily activities. To determine the state of the practice in the use of planning support software in the U.S. transit agencies, a survey was conducted. The survey found that the use of planning support software confirms the general trend in the use of information technology: that is, its use is directly related to the size of the transit agencies. Larger transit agencies tend to use more planning support software, while small agencies do not use that much. Probably one of the most important findings is that many smaller transit agencies consider the purchase and use of planning support software in transit planning, operation, and marketing as unnecessary, especially given the difficulties in obtaining funding, training staff, and hiring and retaining technical support personnel. However, those difficulties are mainly caused by constraints in budgeting and technical staffing issues rather than the undesirability of or the unproved or unrealized benefits related to the use of planning support.


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