Weining Qi, Hongyi Yu, Jinya Yang and Xia Zhang
Abstract‐CEDAR protocol is a distributed routing protocol oriented to Quality of Service (QoS) support in MANET, and bandwidth is the QoS parameter of interest in this protocol…
Abstract
Abstract‐CEDAR protocol is a distributed routing protocol oriented to Quality of Service (QoS) support in MANET, and bandwidth is the QoS parameter of interest in this protocol. However, without energy efficiency consideration, earlier node failure will occur in overloaded nodes in CEDAR, and in turn may lead to network partitioning and reduced network lifetime. The storage and processing overhead of CEDAR is fairly high because too many kinds of control packets are exchanged between nodes and too much state information needs to be maintained by core nodes. The routing algorithm depends fully on the link state information known by core nodes. But the link state information may be imprecise, which will result in route failures. In this paper, we present an improved energy efficient CEDAR protocol, and propose a new efficient method of bandwidth calculation. Simulation results show that the improved CEDAR is efficient in terms of packet delivery ratio, throughput and mean‐square error of energy.
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Much prior literature has discussed bioethics from a Confucian perspective in biomedical research, but little has applied Confucianism in examining ethics in social and behavioral…
Abstract
Purpose
Much prior literature has discussed bioethics from a Confucian perspective in biomedical research, but little has applied Confucianism in examining ethics in social and behavioral research involving human subjects. This paper aims to reexamine the Belmont principles in social and behavioral research from a Confucian perspective to discuss their applicability and limitations and propose implications for revising or extending them potentially in the future.
Design/methodology/approach
A comparison is conducted on bioethics and social and behavioral research ethics. Afterward, a critical analysis is conducted on the Belmont principles of respect for persons, beneficence and justice from a Confucian perspective regarding their application in social and behavioral research.
Findings
From a Confucian perspective, the Belmont principles are necessary but may not be sufficient to cover the width and depth of ethical issues in social and behavioral research, such as those in crowd work-based research. This paper proposes that ethical guidelines for social and behavioral research may need to be updated from the Belmont principles adopting or incorporating certain Confucian ethics.
Originality/value
Social and behavioral research ethics have been relatively marginal compared to the bioethics deliberation in the existing literature. Unlike Beauchamp and Childress’s continued efforts in refining ethical guidelines for biomedical research specifically, little similar work has been done in this area since the Belmont report’s publication in 1979. This paper sheds light on building more refined and specific ethical guidelines to navigate the ever-growing numbers and diversities of nonmedical research topics, methodologies and contexts.
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Jinya Zhang, Yongjiang Li, K. Vafai and Yongxue Zhang
Numerical simulations of a multistage multiphase pump at different operating conditions were performed to study the variational characteristics of flow parameters for each…
Abstract
Purpose
Numerical simulations of a multistage multiphase pump at different operating conditions were performed to study the variational characteristics of flow parameters for each impeller. The simulation results were verified against the experimented results. Because of the compressibility of the gas, inlet volume flow rate qi and inlet flow angle ßi for each impeller decrease gradually from the first to the last stage. The volume flow rate at the entrance of the pump q, rotational speed n and inlet gas volume fraction (IGVF) affect the characteristics of qi and ßi.
Design/methodology/approach
The hydraulic design features of the impellers in the multistage multiphase pump are obtained based on the flow parameter characteristics of the pump. Using the hydraulic setup features, stage-by-stage design of the multistage multiphase pump for a nominal IGVF has been conducted.
Findings
The numerical simulation results show that hydraulic loss in impellers of the optimized pump is substantially reduced. Furthermore, the hydraulic efficiency of the optimized pump increases by 3.29 per cent, which verifies the validation of the method of stage-by-stage design.
Practical implications
Under various operating conditions, qi and ßi decrease gradually from the first to the fifth stage because of the compressibility of the gas. For this characteristic, the fluid behavior varies at each stage of the pump. As such, it is necessary to design impellers stage by stage in a multistage rotodynamic multiphase pump.
Social implications
These results will have substantial effect on various practical operations in the industry. For example, in the development of subsea oilfields, the conventional conveying equipment, which contains liquid-phase pumps, compressors and separators, is replaced by multiphase pumps. Multiphase pumps directly transport the mixture of oil, gas and water from subsea oilwells through a single pipeline, which can simplify equipment usage, decrease backpressure of the wellhead and save capital costs.
Originality/value
Characteristics of a multistage multiphase pump under different operating conditions were investigated along with features of the inlet flow parameters for every impeller at each compression stage. Our simulation results have established that the change in the inlet flow parameters of every impeller is mainly because of the compressibility of the gas. The operational parameters q, n and IGVF all affect the characteristics of qi and ßi. However, the IGVF has the most prominent effect. Lower values of IGVF have an insignificant effect on the gas compressibility. Higher values of IGVF have a significant effect on the gas compressibility. All these characteristics affect the hydraulic design of the impellers for a multistage multiphase pump. In addition, the machining precision should also be considered. Considering all these factors, when IGVF is lower than 10 per cent, all the impellers in the pump can be designed uniformly. When IGVF varies from 10 to 30 per cent, the first two stages should be designed separately, and the latter stages are uniform starting with the second stage. When IGVF varies from 30 to 50 per cent, the first three stages should be designed separately, and the latter stages are going to be similar to the third stage. An additional increase in IGVF results in degeneration of the differential pressure of the pump, which will reduce the compressibility of the gas. As such, it can be deduced that only the first three stages should be designed separately, and the latter stages will be similar to the third stage. In addition, for the pump working under a lower volume flow rate than 25 m3/h, the first three stages should be designed individually while keeping the geometrical structure of the subsequent stages the same as the third stage.
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Qi Wang and Virpi Timonen
Existing research focuses on the pension systems and reforms in China from a macro-level and financial perspective. The expectations of mid-life Chinese people regarding their…
Abstract
Purpose
Existing research focuses on the pension systems and reforms in China from a macro-level and financial perspective. The expectations of mid-life Chinese people regarding their retirement and pensions have been ignored to date, and this research set out to address this lacuna.
Design/methodology/approach
The application of qualitative research methods is relatively novel in Chinese social science. As a grounded theory (GT) study, the research reported here deployed semi-structured interviews to investigate middle-aged Chinese women's and men's perceptions of their pensions and retirement. In total, 36 interviews were conducted, following the constructivist GT method.
Findings
The data point to disparities between the choices and perceptions of individuals on the one hand and the official assumptions underlying the current pension regime on the other hand. Research participants had varying interpretations of the inequality in retirement incomes in China, the main division being between enterprise workers and public-sector employees.
Originality/value
Although there are in principle rigidly fixed retirement ages for men and women in contemporary China, the phenomena of early retirement and working post-retirement are increasing. There are trade-offs between work/retirement and family needs, which influence the choices of middle-aged citizens. Retirement pathways are increasingly individualised, reflecting broader patterns of individualisation and inequality in China.