91 research outputs found

    Impact of HRM System strength and High performance work practices on Service Performance: Considering Mediating Mechanism

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    The purpose of this paper is on how ability enhancing, motivation focused and opportunity creating high performance work practices and employee’s perception of HRM system strength relate to performance outcome i.e. branch service performance in a Bank’s settings. Furthermore, this paper explores the mediation effect of Line mangers ability, motivation and opportunity to implement human resource practices between the high performance work practices, perception of HRM system strength and service performance. Adopted a quantitative research design. Data collected from a sample of 761 employees across 380 different bank branches in Pakistan. Structural equational modeling technique was used to analyze the data. The result supported both content and process perspectives and the positive impact of ability, motivation and opportunity HR practices and HRM system strength on branch service performance. However, the mediation results indicated the partial acceptance. This study provides an empirical evidence of how high performance work practices and employee’s perception of HRM system strength influence branch performance of bank’s employees in developing nation context. The findings of this paper are expected to encourage researchers to be more thoughtful to the connection between organisational HRM system support and HR practices to improve performance within organisations by emphasizing the alignment between Line manager’s AMO and HPWP practices

    Train Localisation using Wireless Sensor Networks

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    Safety and reliability have always been concerns for railway transportation. Knowing the exact location of a train enables the railway system to react to an unusual situation for the safety of human lives and properties. Generally, the accuracy of localisation systems is related with their deployment and maintenance costs, which can be on the order of millions of dollars a year. Despite a lot of research efforts, existing localisation systems based on different technologies are still limited because most of them either require expensive infrastructure (ultrasound and laser), have high database maintenance, computational costs or accumulate errors (vision), offer limited coverage (GPS-dark regions, Wi-Fi, RFID) or provide low accuracy (audible sound). On the other hand, wireless sensor networks (WSNs) offer the potential for a cheap, reliable and accurate solutions for the train localisation system. This thesis proposes a WSN-based train localisation system, in which train location is estimated based on the information gathered through the communication between the anchor sensors deployed along the track and the gateway sensor installed on the train, such as anchor sensors' geographic coordinates and the Received Signal Strength Indicator (RSSI). In the proposed system, timely anchor-gateway communication implies accurate localisation. How to guarantee effective communication between anchor sensors along the track and the gateway sensor on the train is a challenging problem for WSN-based train localisation. I propose a beacon driven sensors wake-up scheme (BWS) to address this problem. BWS allows each anchor sensor to run an asynchronous duty-cycling protocol to conserve energy and establishes an upper bound on the sleep time in one duty cycle to guarantee their timely wake-up once a train approaches. Simulation results show that the BWS scheme can timely wake up the anchor sensors at a very low energy consumption cost. To design an accurate scheme for train localisation, I conducted on-site experiments in an open field, a railway station and a tunnel, and the results show that RSSI can be used as an estimator for train localisation and its applicability increases with the incorporation of another type of data such as location information of anchor sensors. By combining the advantages of RSSI-based distance estimation and Particle Filtering techniques, I designed a Particle-Filter-based train localisation scheme and propose a novel Weighted RSSI Likelihood Function (WRLF) for particle update. The proposed localisation scheme is evaluated through extensive simulations using the data obtained from the on-site measurements. Simulation results demonstrate that the proposed scheme can achieve significant accuracy, where average localisation error stays under 30 cm at the train speed of 40 m=s, 40% anchor sensors failure rate and sparse deployment. In addition, the proposed train localisation scheme is robust to changes in train speed, the deployment density and reliability of anchor sensors. Anchor sensors are prone to hardware and software deterioration such as battery outage and dislocation. Therefore, in order to reduce the negative impacts of these problems, I designed a novel Consensus-based Anchor sensor Management Scheme (CAMS), in which each anchor sensor performs a self-diagnostics and reports the detected faults in the neighbourhood. CAMS can assist the gateway sensor to exclude the input from the faulty anchor sensors. In CAMS, anchor sensors update each other about their opinions on other neighbours and develops consensus to mark faulty sensors. In addition, CAMS also reports the system information such as signal path loss ratio and allows anchor sensors to re-calibrate and verify their geographic coordinates. CAMS is evaluated through extensive simulations based on real data collected from field experiments. This evaluation also incorporated the simulated node failure model in simulations. Though there are no existing WSN-based train localisation systems available to directly compare our results with, the proposed schemes are evaluated with real datasets, theoretical models and existing work wherever it was possible. Overall, the WSN-based train localisation system enables the use of RSSI, with combination of location coordinates of anchor sensors, as location estimator. Due to low cost of sensor devices, the cost of overall system remains low. Further, with duty-cycling operation, energy of the sensor nodes and system is conserved

    Two-Stage Heat Pump using Oil-Free Turbocompressors - System Design and Simulation

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    The combination of multi-stage heat pump cycles with small-scale oil-free turbocompressor technology running on gas bearings could be a promising way to increase performance in domestic and commercial heat pumps. This paper presents a novel two-stage heat pump system with two heat sources at two different temperature levels using two separate turbocompressors rotating on gas bearings optimized for R134a. The system allows integration of unused heat sources, e.g. solar thermal or waste heat, into heat production with a minimal loss of exergy. The cycle comprises an evaporator for the first heat source, a condenser as heat sink, an open economizer with integrated heat exchanger for the second heat source, and a tube-in-tube suction line heat exchanger (SHX) in the high-pressure for superheating and subcooling. The aim of this study is to evaluate theoretically the performance of this heat pump cycle using a system model programmed in the software EES (Engineering Equations Solver). The simulation assumes steady-state, negligible pressure drops and heat losses, and adiabatic expansion processes. The superheating in the evaporator and the SHX is 5°C, and there is no subcooling in the condenser. The heat exchangers are modeled using effectiveness-NTU models. At the design point, the heating capacity of the condenser is set to 6.5 kW and provides hot water of 55°C. The first heat source is brine of 5°C. The second heat source is water of 30°C and has been designed to provide up to 30% of the total condenser heat capacity. The two turbocompressors are designed specifically to meet the heat pump design point. Presently, one-dimensional (1D) compressor maps are used in the heat pump model. Simulation results show that coefficient of performance (COP) improvements of 20% to 30% are achievable, depending on the source temperature levels of the heat pump cycle and the amount of second heat source added to the system. The COP increases with higher source temperatures, higher second heat source capacity, and lower sink temperature. The pressure ratios are defined by the imposed temperature levels. The mass flow rate of the refrigerant in the first stage is mainly determined by the second heat source capacity, and in the second stage by the heat capacity of the condenser. In future work, this novel heat pump concept will be tested experimentally

    Design of Oil-Free Turbocompressors for a Two-Stage Industrial Heat Pump under Variable Operating Conditions

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    Pair of mechanically driven turbocompressors running on gas lubricated bearings have been designed for a two-stage heat pump application functioning under variable operating conditions. Novelty in the present two-stage heat pump system lies in the application of oil-free turbocompressor technology and the introduction of unused secondary heat from various sources. Managing the operational deviations and the secondary heat during off-design heat pump operation is challenging for the turbocompressors. The turbocompressors can potentially exceed their operating range defined by the surge and choke margins, and the maximum rotational speed limit set by the structural and rotordynamic considerations. A wide operating range is, therefore, a prerequisite design condition for the turbocompressors. The present paper will guide the readers through different stages of the design process of such turbocompressors subjected to various constraints. Moreover, a stochastic evaluation on the influence of variable operating conditions on the heat pump and turbocompressor performance will be detailed

    Application of Gene Expression Programming (GEP) for the prediction of compressive strength of geopolymer concrete

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    For the production of geopolymer concrete (GPC), fly-ash (FA) like waste material has been effectively utilized by various researchers. In this paper, the soft computing techniques known as gene expression programming (GEP) are executed to deliver an empirical equation to estimate the compressive strength of GPC made by employing FA. To build a model, a consistent, extensive and reliable data base is compiled through a detailed review of the published research. The compiled data set is comprised of 298 experimental results. The utmost dominant parameters are counted as explanatory variables, in other words, the extra water added as percent FA (), the percentage of plasticizer (), the initial curing temperature (), the age of the specimen (), the curing duration (), the fine aggregate to total aggregate ratio (), the percentage of total aggregate by volume (), the percent SiO2 solids to water ratio () in sodium silicate (Na2SiO3) solution, the NaOH solution molarity (), the activator or alkali to FA ratio (), the sodium oxide (Na2O) to water ratio () for preparing Na2SiO3 solution, and the Na2SiO3 to NaOH ratio (). A GEP empirical equation is proposed to estimate the of GPC made with FA. The accuracy, generalization, and prediction capability of the proposed model was evaluated by performing parametric analysis, applying statistical checks, and then compared with non-linear and linear regression equations

    Organization Performance Influenced by the BSD and Consultative Management Style

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    The purpose of this study is to investigate the relationship among Balanced Scorecard, consultative management style, participative management style and organization size with organizational performance. All the variables are highly correlated with each other. This is an empirical study and data is collected from 100 respondents of service sector from Azad Kashmir. We used five likert scales to collect data from the respondents and data analyzed through SPSS. The result showed that there is a significant positive correlation among variables. This study also indicates that effective management style is necessary for improving the performance of organization. The result indicates that Balanced Scorecard has significant impact on performance of organization. Organization use BSC to handle the complexity and challenges that management faces during their operations. The collection of data is from small area due to time constraint. In the future comparative study can be done with other organizations for better analysis of results

    Enhanced attention using head-mounted virtual reality

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    Some evidence suggests that experiencing a given scenario using virtual reality (VR) may engage greater attentional resources than experiencing the same scenario on a 2D computer monitor. However, the underlying neural processes associated with these VR-related effects, especially those pertaining to current consumer-friendly head-mounted displays of virtual reality (HMD-VR), remain unclear. Here, two experiments were conducted to compare task performance and EEG-based neural metrics captured during a perceptual discrimination task presented on two different viewing platforms. Forty participants (20–25 years old) completed this task using both an HMD-VR and traditional computer monitor in a within-group, randomized design. Although Experiment I (n = 20) was solely behavioral in design, Experiment II (n = 20) utilized combined EEG recordings to interrogate the neural correlates underlying potential performance differences across platforms. These experiments revealed that (1) there was no significant difference in the amount of arousal measured between platforms and (2) selective attention abilities in HMD-VR environment were enhanced from both a behavioral and neural perspective. These findings suggest that the allocation of attentional resources in HMD-VR may be superior to approaches more typically used to assess these abilities (e.g., desktop/laptop/tablet computers with 2D screens)

    Impact of CSR, Quality of Work Life and Organizational Structure on Employee’s Performance in Pakistan

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    The trends of organizations are changing and demanding satisfied employees rather than dissatisfied employees. This paper provides factors through which employee’s performance can be increased to achieve organizational goals and objectives. To attract the motivated employees and building relations, CSR can perform for society which will change the thoughts of stakeholders. Quality of work life has impact on organization’s effectiveness which is essential for firms to be healthy and productive. Firms should adopt employee oriented policies which satisfies them to achieve organizational objectives. This study also indicates that effective organizational structure is necessary for improving the performance of employees and the organization. The structure is a source of success or failure because it empowers the employee which will increase the sense of responsibility. For the improvement in the organization and removing stress of the employees management must consider the hygiene factors to motivate the employees. The conceptualized work is conducted which is proved through evidence. For further study statistical analysis can be done for confirmation of the hypothesis

    THE AGE DISTRIBUTION AND EFFECTIVENESS OF LOW DOSE TAMSULOSIN IN LOWER URETERIC STONES

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    Objective: To determine the effectiveness of low dose tamsulosin as a medical expulsive therapy in patients with lower ureteric stones. Patients and Methods: The six months randomized control trial was conducted on all patients with either gender, age range 30-60 years and stone size 4-10 mm in the lower 1/3rd of the ureter determined on ultrasound at tertiary care hospital. Group A patients was offered low dose tamsulosin (0.2 mg) one tablet daily in the morning for a maximum of 4 weeks and group B served as control. The final outcome was measured at the end of 4th week of treatment. Patients were instructed to note the time and the date of expulsion of stone. Absence of echoic shadows on lower 1/3rd of ureteric line on ultrasound was taken as effectiveness (expulsion of stone). Results: In control group mean age was 45.52 ±6.70 years whereas in low dose Tamsulin mean age was 46.72 ±6.73 years. Frequency of male was higher in both control and low dose Tamsulin group, i.e. 39 (78%) and 21 (42%) respectively. In control group effectiveness was found 3 (6%) patients whereas in low dose Tamsulin group effectiveness was found in 47 (94%). Conclusion: In our study the effectiveness of low dose tamsulosin as a medical expulsive therapy in patients with lower ureteric stones was higher as compared to control. Keywords: Low dose tamsulosin, Lower ureteric stones, Medical expulsive therap
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