Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant b...Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant benefits to spectral utilization and system capacity. The interference management and access control for open and closed femtocells in two-tier HetNets were focused. The contributions consist of two parts. Firstly, in order to reduce the uplink interference caused by MUEs (macrocell user equipments) at closed femtocells, an incentive mechanism to implement interference mitigation was proposed. It encourages femtoeells that work with closed-subscriber-group (CSG) to allow the interfering MUEs access in but only via uplink, which can reduce the interference significantly and also benefit the marco-tier. The interference issue was then studied in open-subscriber-group (OSG) femtocells from the perspective of handover and mobility prediction. Inbound handover provides an alternative solution for open femtocells when interference turns up, while this accompanies with PCI (physical cell identity) confusion during inbound handover. To reduce the PCI confusion, a dynamic PCI allocation scheme was proposed, by which the high handin femtocells have the dedicated PCI while the others share the reuse PCIs. A Markov chain based mobility prediction algorithm was designed to decide whether the femtoeell status is with high handover requests. Numerical analysis reveals that the UL interference is managed well for the CSG femtocell and the PCI confusion issue is mitigated greatly in OSG femtocell compared to the conventional approaches.展开更多
In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict pla...In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N) model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM(1,N) model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.展开更多
The risk of violence in psychiatric settings implies the assessment of dynamic predictors to adjust nursing interventions. So as to identify the pattern of aggressive behaviors, assess the dynamic predictors of violen...The risk of violence in psychiatric settings implies the assessment of dynamic predictors to adjust nursing interventions. So as to identify the pattern of aggressive behaviors, assess the dynamic predictors of violence in hospitalized patients, and analyze the predictive qualities of the Brcset Violence Checklist (BVC), an exploratory/descriptive study was conducted in psychiatric wards in Coimbra, Portugal. The instruments used were: the staff observation aggression scale-revised (SOAS-R), visual analogue scale (VAS), and the BVC. For the period of a month, 64 patients with a mean age of 29 years, unemployed, and with psychotic disorders were observed. In this group, 13 people displayed 15 aggressive behaviors of moderate severity, which had consequences for nurses; they were triggered by the denial of something through verbal aggression and controlled by non-restrictive measures. The most common predictors of violence were irritability and boisterousness. It was also concluded that the BVC shows good predictive characteristics (sensitivity and specificity) of violence, thus, it may be considered as a useful and effective instrument to assess the risk of violence and, consequently, to adjust nursing interventions to prevent this phenomenon.展开更多
Temperature sensitivity of waxy crude oils makes it difficult to study their flow behaviour in the presence of water especially near their wax appearance temperature (WAT). In this study a method was proposed and im...Temperature sensitivity of waxy crude oils makes it difficult to study their flow behaviour in the presence of water especially near their wax appearance temperature (WAT). In this study a method was proposed and implemented to mitigate such difficulties which was applied in predicting mixture temperatures (Tin) of a typical Malaysian waxy crude oil and water flow in a horizontal pipe. To this end, two analytical models were derived firstly from calorimetry equation which based on developed two correlations for defining crude oil heat capacity actualized from the existed specific heat capacities of crude oils. The models were then applied for a set of experiments to reach the defined three predetermined Tm (26 ℃, 28 ℃ and 30 ℃). The comparison between the predicted mixture temperatures (Tin,1 and Tin,2) from the two models and the experimental results displayed acceptable absolute average errors (0.80% 0.62%, 0.53% for model 1; 0,74%, 0.54%, 0.52% for model 2). Moreover, the average errors for both models are in the range of standard error limits (4-0,75Z) according to ASTM E230. Conclusively, the proposed model showed the ease of obtaining mixture temperatures close to WAT as predetermined with accuracy of ± 0.5 ℃approximately for over 84% of the examined cases. The method is seen as a practical reference point to further study the flow behaviour of waxy crudes in oil-water two-phase flow system near sensitive temperatures.展开更多
This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in capti...This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World(Qingdao, China) showed signifi cant variations of the rates of both the total sounds and sound classes(whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate(3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival(13.08 s/m/d). The high rate was maintained or intensifi ed throughout the food delivery(25.12 s/m/d), and then reduced immediately after the animals were fed(9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.展开更多
基金Project(2012AA01A301-01)supported by the National High-Tech Research and Development Plan of ChinaProjects(61301148,61272061)supported by the National Natural Science Foundation of China+3 种基金Projects(20120161120019,2013016111002)supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProjects(14JJ7023,10JJ5069)supported by the Natural Science Foundation of Hunan Province,ChinaProject(ISN12-05)supported by State Key Laboratory of Integrated Services Networks Open Foundation,ChinaProject(531107040276)supported by the Fundamental Research Funds for the Central Universities,China
文摘Abstract: Two-tier heterogeneous networks (HetNets), where the current cellular networks, i.e., macrocells, are overlapped with a large number of randomly distributed femtocells, can potentially bring significant benefits to spectral utilization and system capacity. The interference management and access control for open and closed femtocells in two-tier HetNets were focused. The contributions consist of two parts. Firstly, in order to reduce the uplink interference caused by MUEs (macrocell user equipments) at closed femtocells, an incentive mechanism to implement interference mitigation was proposed. It encourages femtoeells that work with closed-subscriber-group (CSG) to allow the interfering MUEs access in but only via uplink, which can reduce the interference significantly and also benefit the marco-tier. The interference issue was then studied in open-subscriber-group (OSG) femtocells from the perspective of handover and mobility prediction. Inbound handover provides an alternative solution for open femtocells when interference turns up, while this accompanies with PCI (physical cell identity) confusion during inbound handover. To reduce the PCI confusion, a dynamic PCI allocation scheme was proposed, by which the high handin femtocells have the dedicated PCI while the others share the reuse PCIs. A Markov chain based mobility prediction algorithm was designed to decide whether the femtoeell status is with high handover requests. Numerical analysis reveals that the UL interference is managed well for the CSG femtocell and the PCI confusion issue is mitigated greatly in OSG femtocell compared to the conventional approaches.
基金Supported by the Foundation of State Key Laboratory of Autonomous Underwater Vehicle, Harbin Engineering Universitythe Fundamental Research Funds for the Central Universities (HEUCFL20101113)
文摘In order to minimize the harm caused by the instability of a planing craft, a motion prediction model is essential. This paper analyzed the feasibility of using an MGM(1,N) model in grey system theory to predict planing craft motion and carried out the numerical simulation experiment. According to the characteristics of planing craft motion, a recurrence formula was proposed of the parameter matrix of an MGMfl,N) model. Using this formula, data can be updated in real-time without increasing computational complexity significantly. The results of numerical simulation show that using an MGM(1,N) model to predict planing motion is feasible and useful for prediction. So the method proposed in this study can reflect the planing craft motion mechanism successfully, and has rational and effective functions of forecasting and analyzing trends.
文摘The risk of violence in psychiatric settings implies the assessment of dynamic predictors to adjust nursing interventions. So as to identify the pattern of aggressive behaviors, assess the dynamic predictors of violence in hospitalized patients, and analyze the predictive qualities of the Brcset Violence Checklist (BVC), an exploratory/descriptive study was conducted in psychiatric wards in Coimbra, Portugal. The instruments used were: the staff observation aggression scale-revised (SOAS-R), visual analogue scale (VAS), and the BVC. For the period of a month, 64 patients with a mean age of 29 years, unemployed, and with psychotic disorders were observed. In this group, 13 people displayed 15 aggressive behaviors of moderate severity, which had consequences for nurses; they were triggered by the denial of something through verbal aggression and controlled by non-restrictive measures. The most common predictors of violence were irritability and boisterousness. It was also concluded that the BVC shows good predictive characteristics (sensitivity and specificity) of violence, thus, it may be considered as a useful and effective instrument to assess the risk of violence and, consequently, to adjust nursing interventions to prevent this phenomenon.
基金Supported by the Malaysia's Ministry of Higher Education(FRGS/4F136)the University Teknologi Malaysia(RUG/01H68)
文摘Temperature sensitivity of waxy crude oils makes it difficult to study their flow behaviour in the presence of water especially near their wax appearance temperature (WAT). In this study a method was proposed and implemented to mitigate such difficulties which was applied in predicting mixture temperatures (Tin) of a typical Malaysian waxy crude oil and water flow in a horizontal pipe. To this end, two analytical models were derived firstly from calorimetry equation which based on developed two correlations for defining crude oil heat capacity actualized from the existed specific heat capacities of crude oils. The models were then applied for a set of experiments to reach the defined three predetermined Tm (26 ℃, 28 ℃ and 30 ℃). The comparison between the predicted mixture temperatures (Tin,1 and Tin,2) from the two models and the experimental results displayed acceptable absolute average errors (0.80% 0.62%, 0.53% for model 1; 0,74%, 0.54%, 0.52% for model 2). Moreover, the average errors for both models are in the range of standard error limits (4-0,75Z) according to ASTM E230. Conclusively, the proposed model showed the ease of obtaining mixture temperatures close to WAT as predetermined with accuracy of ± 0.5 ℃approximately for over 84% of the examined cases. The method is seen as a practical reference point to further study the flow behaviour of waxy crudes in oil-water two-phase flow system near sensitive temperatures.
基金Supported by grants from the Institute of Hydrobiology,Chinese Academy of Sciences
文摘This study examines whether a group of captive false killer whales(P seudorca crassidens) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World(Qingdao, China) showed signifi cant variations of the rates of both the total sounds and sound classes(whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate(3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival(13.08 s/m/d). The high rate was maintained or intensifi ed throughout the food delivery(25.12 s/m/d), and then reduced immediately after the animals were fed(9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.