Explicit Reservation Research Articles

Performance of Priority-Based Traffic Coexistence Strategies in 5G mmWave Industrial Deployments

Recently standardized New Radio (NR) technology supports both ultra-reliable low-latency (URLLC) service and conventional enhanced mobile broadband (eMBB) service. Owing to extreme latency and reliability requirements an explicit prioritization needs to be provided to URLLC service when these traffic types are mixed up at the air interface. In this work, we consider simultaneous support of these two services in an industrial environment, where production line equipment utilizes URLLC service for reorganization and synchronous operation while eMBB service is used for remote monitoring. By utilizing the tools of stochastic geometry and queuing theory, we formalize the model with pre-emptive priority service at NR base station (BS) with and without direct device-to-device (D2D) communications. Our numerical results indicate that the priority-based implementation of URLLC and eMBB coexistence allows us to isolate the former traffic efficiently and requires no external control. D2D-aware strategy, where the BS explicitly reserves some resources for direct communications, drastically outperforms those, where no explicit reservation is utilized, as well as the baseline strategy where all the traffic goes through the BS. This strategy can achieve 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−5</sup> of URLLC drop probability when the baseline strategy produces just <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\times 10^{-3}$ </tex-math></inline-formula> , leading to three orders of magnitude reduction in drop probability and without significant impact produced on eMBB session drop probability. The developed model can be utilized to estimate the NR BS density required to support prescribed performance guarantees for all the considered strategies.

Coercive interventions under the new Dutch mental health law: Towards a CRPD-compliant law?

The Netherlands became State Party to the United Nation Convention on the Rights of Persons with Disabilities (CRPD) in 2016, a treaty that holds great promise for promoting and protecting human rights of persons with mental disorders. Yet, the Dutch government also made explicit reservations to the Convention. On 1 January 2020, the Netherlands introduced a new mental health law, the Compulsory Mental Health Care Act (CMHCA), which aims to strengthen the legal status of persons with psychiatric illnesses. To which extent does the new Dutch mental health law comply with the regulations as outlined in the CRPD? In this article, we examine how coercive interventions, specifically the elements of competence, involuntary treatment and involuntary admission are regulated in the domestic legislation and compare them to the CRPD approach. A normative analysis combined with literature review helps to understand the law, reveal the gaps and uncover the barriers that remain. Is there a need to reassess the domestic legal provisions allowing for coercive treatment, and if so, what advancements are required? After all, should the CRPD be strictly adhered to at all times?

The road ahead: should Hong Kong develop five pillars of old age protection?

PurposeThis paper demonstrates that Hong Kong currently provides four pillars of old-age protection: a publicly managed and noncontributory social security system (zero pillar), a funded contribution scheme (the second pillar), voluntary personal savings (the third pillar) and informal support, formal social programs and other individual financial assets (the fourth pillar). This paper aims at evaluating current four pillars of old-age protection and unraveling the deep-seated causes underlying the current old-age protection model by tracing a short history from 1965 onward. This paper aims at making recommendations about the current old-age protection model.Design/methodology/approachThe paper analyzes the current four pillars of old age protection. A comprehensive literature review was conducted covering relevant government reports, academics' journal papers and nongovernmental organizations' reports concerning the development of old age protection system from 1965 to the present.FindingsThe poverty rate of elderly residents was approximately 44.5% between 2009 and 2018, indicating that the four pillars of old-age protection had been unable to alleviate poverty in the aging population. The development of the current four pillars is attributed to a residual welfare system, the effectiveness of which is further dependent on familial dependence or welfare financialization. However, the reliability of familial dependence is affected by the declining coresidence rate and low fertility rate, whereas welfare financialization not only predominately favors financial institutions but also exacerbates income polarization. Therefore, the University of Hong Kong (2014) introduced an additional pillar of noncontributory social pension and assistance, which generated a contentious debate. The Hong Kong Special Administrative Region (HKSAR) government initiated a public engagement exercise on retirement protection in 2015 to assess public opinion on old-age protection. These consultation exercises were met with broad public disappointment because of the explicit reservations imposed by the government on the proposals.Practical implicationsAlthough the government's resistant attitude can be attributed to the residual welfare system, pension reform needs to be urgently implemented at three levels, namely strengthening of each pillar, emphasis on the pillar's interrelatedness and introduction of the first pillar.Originality/valueThe poverty of the elderly population is serious in Hong Kong. It is important to solve the deep-seated problems faced by the current old-age protection model. Hence, it comes a critical time to design a sustainable old-age protection model despite the heated discussion on the establishment of a central provident fund and pension system among officials since 1960s.

Automated Fine-Grained CPU Cap Control in Serverless Computing Platform

Serverless computing has emerged as a new cloud computing execution model that liberates users and application developers from explicitly managing `physical' resources, leaving such a resource management burden to service providers. In this article, we study the problem of resource allocation for multi-tenant serverless computing platforms explicitly taking into account workload fluctuations including sudden surges. In particular, we investigate different root causes of performance degradation in these platforms where tenants (their applications) have different workload characteristics. To this end, we develop a fine-grained CPU cap control solution as a resource manager that dynamically adjusts CPU usage limit (or CPU cap) concerning applications with same/similar performance requirements, i.e., application groups. The adjustment of CPU caps applies primarily to co-located worker processes of serverless computing platforms to minimize resource contention, which is the major source of performance degradation. The actual adjustment decisions are made based on performance metrics (e.g., throttled time and queue length) using a group-aware scheduling algorithm. The extensive experimental results performed in our local cluster confirm that the proposed resource manager can effectively eliminate the burden of explicit reservation of computing capacity, even when fluctuations and sudden surges in the incoming workload exist. We measure the robustness of the proposed resource manager by comparing it with several heuristics which extensively used in practice, including the enhanced version of round robin and the least length queue scheduling policies, under various workload intensities driven by real-world scenarios. Notably, our resource manager outperforms other heuristics by decreasing skewness and average response time up to 44 and 94 percent, respectively, while it does not over-use the CPU resources.

THE OVERVIEW OF METHOD OF BALANCED RESOURSE RESERVATION AND MULTICAST ROUTING IN TELECOMMUNICATION NETWORK

The overview of a mathematical model for multicast routing supporting shared explicit reservation of link resource was presented, which is introduced by linear expressions that responsible for ensuring the connectivity of the calculated multicast routes, as well as the absence of loops in them. The novelty of the model consists in introducing conditions for preventing congestion of communication links when implementing a shared explicit reservation, in which a link resource is allocated to several flows simultaneously, but the list of these flows is strictly defined. The task of routing multicast flows supporting shared explicit reservation of link resource is formulated as an optimization problem of mixed integer linear programming. The use of the proposed model makes it possible to exploit the available link resource more efficiently (on average, from 15 to 25%) by ensuring the consistency of solutions for multicast routing tasks and organizing of the shared explicit reservation.

Prioritizing the protection of climate refugia: designing a climate-ready protected area network

Protected areas are the primary strategy for maintaining natural landscapes and separating biodiversity features from preventable anthropogenic threats. The Convention on Biological Diversity calls for the coverage of at least 17% of land by protected areas, and the strategic prioritization of important biodiversity areas. Using the spatially explicit reserve design software, Marxan, this study combines climate refugia modelled under future climates in the year 2070 and bioregions to identify priority sites for protected area expansion under climate change in the state of New South Wales (NSW), Australia. Priority sites for new protected areas that meet bioregion and climate refugia targets were identified in central-western, northeast and patches of southeast NSW. Seven existing parks, including Kosciuszko National Park, overlapped with regions identified repeatedly as climate refugia under 12 future climate scenarios. The recommendations from this study support policy-makers in prioritizing the protection of biodiversity under a changing and uncertain climate.

Design and Analysis of QoS Routing Framework integrated with OLSR protocol for Multimedia Traffic in Mobile Adhoc Networks

MANETs (Mobile Ad-hoc Networks) is the self organizing wireless structure of mobile hosts. Wireless media is used for communication in MANETs. Considering the developing requirements for multimedia and real-time traffic applications in real world, QoS (Quality-of-Service) support is essential in MANETs. But most of the characteristics of MANETs make QoS support a difficult problem. It is challenging to support QoS routing in MANET due to dynamic behavior and mobility of the hosts. The OLSR (Optimized Link State Routing) protocol can be efficiently used in MANETs to provide QoS routing because of its dynamic MPR (Multi Point Relay) selection criteria and proactive nature. In this paper, a design of QoS routing framework integrated with OLSR protocol is proposed and also analyzed using network simulator. Proposed QoS framework combines a bandwidth estimation algorithm with explicit resource reservation, QoS routing and connection admission control (CAC). OLSR protocol is extended for QoS framework to solve performance issues related to node mobility using cross layer approach. Results after simulation conclude about efficiency of the proposed QoS routing framework.

An assessment of flexibility reserves in stochastic modeling at multiple timescales

Due to recent technological achievements, stochastic optimization, which inherently captures the uncertainty of intermittent resources, is being used to capture the variability and uncertainty of wind and solar resources. However, due to persistent computational limitations, it is not practical to consider all possible variable generation scenarios. As a result, a reduced number of most likely scenarios is usually considered. While this helps reduce the computational burden, it also leaves the system operator vulnerable to some risk. In order to address this issue, this paper aims at providing insight into using an explicit reserve requirement in a stochastic modeling framework in order to provide system operators with greater confidence in stochastic dispatch solutions. This is accomplished by simulating a modified version of the IEEE 118 bus system in a fully stochastic, multi-timescale framework with flexibility reserve requirements. Results show that utilizing a stochastic flexibility reserve requirement within the stochastic modeling framework offers the most reliability benefit.

The role of cultural background in the personalization principle: Five experiments with Czech learners

Composing instructional texts in multimedia learning materials in a conversational style rather than a formal style can facilitate learning. We investigated whether a specific language/cultural background could present a boundary condition for this effect. In four experiments with a Czech sample (N = 278), we replicated a seminal experiment conducted on a US sample (with a short animation on the topic of lightning formation), which demonstrated a large effect size in favor of the instructional texts in the conversational style. In our four experiments, we varied between two types of audiences (a college and a high school audience) and two types of short animations (the original one and a complementary one). Instructional texts in a conversational style brought no overall advantage for the Czech audience (ηp2 = .00; the high school audience: d = 0.48, 0.22; the college audience: d = −0.45, −0.04). Twenty-nine percent of participants who received the conversational instructional texts expressed explicit reservations regarding the style of the language. In the fifth supplementary experiment, Czech participants (N = 138) had to rate preferences on computer tutor’s printed statements. Direct rather than polite statements were preferred. Limited benefits of conversational/polite instructional texts for Czech learners are probably related to the generally more formal approach to education in the Czech Republic compared to the US schooling system. We also failed to find a link between several affective variables and learning outcomes; with the exception of a relationship of generalized positive affect, levels of flow and perceived difficulty to some of the learning outcomes.

Reserves in Stochastic Unit Commitment: An Irish System Case Study

As the level of variable renewable sources integrated into the power system increases, their nature forces a re-evaluation of traditional methodologies for managing uncertainty in power generation. This paper quantifies the interaction among the implicit reserve carried by a rolling planning stochastic unit commitment, deterministic reserve criteria, and the quality of information around wind forecast error, for a fully isolated 2020 Irish system. To perform this, three case studies were run. The first demonstrates that the implicit reserve carried by the stochastic model causes the implicit value of lost load set by the inclusion of explicit reserve requirements to be disproportionately high compared to the deterministic model. The second demonstrates that the relative value of the reserve rules does not have consistent impact between the models. In the final case, it is shown that the forecast error information utilized changes the security behavior of stochastic models. This is of importance, given the frequency at which normal distributions are used to model wind forecast error. Together, these results indicate a need for a holistic solution to reserve provision which considers the implicit nature of stochastic models, and forecast error assumptions when deciding reserve criteria.

Designing a multi-species spatially explicit nature reserve network construction framework based on extinction probability: A case study of Wuyishan city

With the purpose of species’ long-term persistence, nature reserve network construction has been acknowledged as a simple yet effective way to protect species to avoid anthropogenic activities. This study focused on the identification and construction of multi-species spatially explicit reserve networks in nature reserves. A three-step framework was proposed considering both species representation and elimination of the negative impact the anthropogenic barriers impose on species turnover. We detected the subset of anthropogenic barriers responsible for the failure of species’ direct dispersals between fixed representative reserves and then added constructed reserves to remove these influences. The proposed framework was applied to Macaca thibetana and Lophura nycthemera, two sensitive species in Wuyishan. The results showed that when designing a reserve network only for M. thibetana, four representative reserves, one constructed reserve and two migration routes were identified. Taking both M. thibetana and L. nycthemera as targeted species, a reserve network including ten representative reserves, three constructed reserves and fifteen dispersal routes was selected, covering 43.17% of the total area of Wuyishan Nature Reserve. The selection of constructed reserves significantly lowers the extinction probabilities of both M. thibetana and L. nycthemera in either reserve or the whole network. In addition, by comparing the fixed reserve network with current functional zoning of WYS, 83% of the reserve network lay in the core zone, while 11.28% and 5.72% located in the buffer zone and transition zone, respectively. The results suggested that the current core zone in Wuyishan Nature Reserve General Planning should be extended by replanning and restricting the tourism and roads to be out of the constructed reserves and the direct dispersal pathways between constructed reserves and the corresponding reconnected representative reserves. Such a framework is a necessary post-evaluation that can provide an effective way facing multi-species protection and provide guidance to policy decisions.

Automated Fine-Grained CPU Provisioning for Virtual Machines

Ideally, the pay-as-you-go model of Infrastructure as a Service (IaaS) clouds should enable users to rent just enough resources (e.g., CPU or memory bandwidth) to fulfill their service level objectives (SLOs). Achieving this goal is hard on current IaaS offers, which require users to explicitly specify the amount of resources to reserve; this requirement is nontrivial for users, because estimating the amount of resources needed to attain application-level SLOs is often complex, especially when resources are virtualized and the service provider colocates virtual machines (VMs) on host nodes. For this reason, users who deploy VMs subject to SLOs are usually prone to overprovisioning resources, thus resulting in inflated business costs. This article tackles this issue with AutoPro : a runtime system that enhances IaaS clouds with automated and fine-grained resource provisioning based on performance SLOs. Our main contribution with AutoPro is filling the gap between application-level performance SLOs and allocation of a contended resource, without requiring explicit reservations from users. In this article, we focus on CPU bandwidth allocation to throughput-driven, compute-intensive multithreaded applications colocated on a multicore processor; we show that a theoretically sound, yet simple, control strategy can enable automated fine-grained allocation of this contended resource, without the need for offline profiling. Additionally, AutoPro helps service providers optimize infrastructure utilization by provisioning idle resources to best-effort workloads, so as to maximize node-level utilization. Our extensive experimental evaluation confirms that AutoPro is able to automatically determine and enforce allocations to meet performance SLOs while maximizing node-level utilization by supporting batch workloads on a best-effort basis.

Explicit reservation of cache memory in a predictable, preemptive multitasking real-time system

We describe and evaluate explicit reservation of cache memory to reduce the cache-related preemption delay (CRPD) observed when tasks share a cache in a preemptive multitasking hard real-time system. We demonstrate the approach using measurements obtained from a hardware prototype, and present schedulability analyses for systems that share a cache by explicit reservation. These analyses form the basis for a series of experiments to further evaluate the approach. We find that explicit reservation is most useful for larger task sets with high utilization. Some task sets cannot be scheduled with a conventional cache, but are schedulable with explicit reservation.

Extinction Resilience of Island Species: An Amphibian Case and a Predictive Model

Extreme overall divergence and high extinction rates are typical of insular endemics. Thus, detecting and understanding nativeness is critical on islands. Resilience to extinction is explored through a mechanistic approach focusing on midwife toads (Anura: Alytidae: Alytinae), an ancient lineage that includes continental and insular species. All alytines need urgent conservation action, including control of emerging diseases and spatially explicit reserve design aimed at ensuring ecosystem health and connectivity. The only extant insular alytine is additionally affected by an introduced continental predator. This alien species acts as a driver of the prey’s near-extinction and has not elicited any evolutionary response. Both IUCN criteria and EDGE scores show that alytines are top conservation priorities. However, there is a need for also considering phenotypic and ecological uniqueness in the assessment of conservation status and urgency. The reason is that phenotypes render ecosystems functional and insular ones uniquely so. In contrast, phylogenetic relatedness is just a constraint upon, not a motor of, evolutionary novelty. Insular species are indeed particularly susceptible, but can be similarly endangered as continental ones. This paradox may be solved by recognizing the insularity syndrome in any isolated or nearly-insular ecosystem, as a function of evolutionary and dispersal potentials. This predictive model may be useful for island biogeography, invasion biology and conservation planning.

Spatially explicit mortality of California spiny lobster (Panulirus interruptus) across a marine reserve network

SUMMARYStudies of marine reserves typically focus upon differences in the size and abundance of target organisms inside versus outside reserve borders, but they seldom provide spatially explicit measurements of how reserves influence mortality rates. This study investigated mortality rates for female California spiny lobster (Panulirus interruptus) at multiple sites inside and outside of three marine reserves at the Santa Barbara Channel Islands, California, USA. Mean total mortality (Z) of female lobsters was lower at sites inside reserves (Z = 0.22 [± 0.05 SE]) than at sites outside reserves (Z = 0.59 [± 0.02 SE]). Mean mortality at all sites inside reserves, and among sites near reserve centres (where Z = 0.17 [± 0.05 SE]), was similar to estimates of natural mortality for other temperate spiny lobster species. Among sites inside reserves, there was a positive relationship between mortality and proximity to reserve borders, but this relationship was absent among sites outside reserves. Mortality estimates were much more variable among sites inside reserves than at sites in fished areas. This variation is probably due to differential emigration rates from the three reserves, as well as site-specific ecological factors that influence population structure, demonstrating the importance of spatially explicit reserve sampling and understanding how ecological heterogeneity influences fisheries models.

Precongestion notification: new QoS support for differentiated services IP networks

Admission control is a well-known technique to explicitly admit or block new flows in order to keep a network's traffic load at a moderate level and to guarantee QoS for admitted flows. Flow termination is a new flow control function that terminates some admitted flows when the network capacity does not suffice, such as in the case of unexpected failures. Admission control and flow termination are useful to protect QoS for inelastic flows that require a minimum bit rate. Examples are real-time applications like voice and video. Precongestion notification (PCN) provides feedback about load conditions on the path to boundary nodes. They use this information to implement lightweight admission control and flow termination without per-flow state on interior nodes of a domain. These mechanisms are significantly simpler than explicit reservation schemes. In the context of DiffServ, IP, MPLS, and Ethernet networks, we explain the concept of PCN-based admission control and flow termination, present recent standards of the IETF, and discuss benefits and limitations.

Psychiatrists' Use of Shared Decision Making in the Treatment of Schizophrenia: Patient Characteristics and Decision Topics

Psychiatrists' Use of Shared Decision Making in the Treatment of Schizophrenia: Patient Characteristics and Decision Topics

A Reservation-based Extended Transaction Protocol for Coordination of Web Services

Web services can be used to automate business activities that span multiple enterprises over the Internet. Such business activities require a coordination protocol to reach consistent results among the participants in the business activity. In the current state of the art, either classical distributed transactions or extended transactions with compensating transactions are used. However, classical distributed transactions lock data in the databases of different enterprises for unacceptable durations or involve repeated retries, and compensating transactions can lead to inconsistencies in the databases of the different enterprises. In this article, we describe a novel reservation protocol that can be used to coordinate the tasks of a business activity. Instead of resorting to compensating transactions, the reservation protocol employs an explicit reservation phase and an explicit confirmation and cancellation phase. We show how our reservation protocol maps to the Web services coordination specification, and describe our implementation of the reservation protocol. We compare the performance of the reservation protocol with that of the two-phase commit protocol and optimistic two-phase commit protocol. We also compare the probability of inconsistency for the reservation protocol with that for compensating transactions.

A capacity acquisition protocol for channel reservation in CDMA networks

In this paper, a capacity acquisition protocol is proposed for channel reservation in CDMA networks. Under this protocol, a cell is virtually divided into three regions (i.e., inner region, forced handoff region, and active handoff region). A new call in the active handoff region works in soft handoff mode upon its admission, while a new call in the inner and forced handoff regions works in single mode. However, in the forced handoff region, calls working in single mode can be forced into soft handoff mode, when extra capacity is needed by soft handoff calls. As a result, no explicit channel reservation is required before a call enters soft handoff. By adjusting the size of the forced handoff region, the capacity acquisition can adapt to traffic load and guarantee a desired call dropping probability. To evaluate the capacity acquisition protocol, an analytical model is derived and is also validated through computer simulations. Numeric results illustrate that the capacity acquisition protocol significantly reduces the call dropping probability.

Using explicit reservations to arbitrate access to a metropolitan system of slotted interconnected rings combining TDMA and WDMA

A system of slotted interconnected wavelength-division-multiplexing (WDM) rings controlled by a medium access control (MAC) protocol is shown to offer very high utilization within a queuing delay less than a few round-trip times, by means of a very-fast-reacting explicit reservation mechanism. The system can be used to provide interconnectivity in a metropolitan area transferring optical payloads on-the-fly without buffering or converting from the optical domain. All necessary control information is transferred on a dedicated wavelength and is processed in the electrical domain to provide both collision-free packet access at the ring nodes and contention resolution at the hub interconnecting the rings. The end result is a flexible and efficient metropolitan network suitable for bursty data services.