Search results

The purpose of this paper is to research the impact of hybrid series‐parallel and parallel‐series system configurations on system performances based on system reliability and to develop a configuration model to meet the requirement of reconfigurable manufacturing system (RMS).

Based on the criterion of system reliability, a RMS configuration model is presented – the hybrid parallel‐series model with waiting system characteristics. The configuration model is evaluated from reliability, productivity, and cost by combining system engineering theory, Boolean algebra methodology with statistical analysis theory. The model reliability has been used to ameliorate by adopting the integrated algorithm based on Shrama and Misra optimization algorithm.

The need for application of this method and model – some constraints must be limited, the hybrid parallel‐series configuration is superior and the integrated algorithm is effective to RMS system configuration.

Cost constraints, equipment weight constraints, and function independency of equipment are main limitations.

The model and method have been used to ameliorate the reconfigurable automobile parts product line in SH automobile motor company of Shanghai. The operation result illustrates the validity of this configuration model and algorithm.

The new RMSs configuration model has been proposed. The new algorithm is proposed to ameliorate and optimize a reconfigurable product line with the integrated algorithm based on Shrama and Misra algorithm. The actual running effect is significant.

Hybrid journal bearing have long been used in machines requiring large load and high speed capacity operating under wide range of temperatures. Different compensating devices are used in for efficient operation of bearings. This paper aims to help in selection of optimum compensating device by evaluating the comparative performance of constant flow valve, capillary compensated and slot entry hybrid journal bearing under the combined influence of thermal effects and micropolar nature of lubricant.

The variation in micropolar parameters and viscosity change due to temperature increase of lubricant are considered in present study. Finite element method is used for combined iterative solution of micropolar Reynolds, energy and conduction equations. Micropolar lubricant is assumed to be governed by two parameters, coupling number and characteristic length. The results in the study are presented for symmetric and asymmetric configurations of hole entry and slot entry non-recessed hybrid journal bearings

The results indicate that constant flow valve compensated hole entry hybrid journal bearing is the highest performing bearing for the given range of micropolar parameters of lubricant in terms of maximum fluid pressure and dynamic coefficients.

The performance variations of various configurations of hybrid journal bearing are presented in a single paper. The reader can get overview of combined effects of micropolar parameters and viscosity decrease due to temperature increase of the lubricant.

This paper aims to describe a novel hybrid inertial measurement unit (IMU) for motion capturing via a new configuration of strategically distributed inertial sensors, and a calibration approach for the accelerometer and gyroscope sensors mounted in a flight vehicle motion tracker built on the inertial navigation system.

The hybrid-IMU is designed with five accelerometers and one auxiliary gyroscope instead of the accelerometer and gyroscope triads in the conventional IMU.

Simulation studies for tracking with both attitude angles and translational movement of a flight vehicle are conducted to illustrate the effectiveness of the proposed method.

The cross-quadratic terms of angular velocity are selected to process the direct measurements of angular velocities of body frame and to avoid the integration of angular acceleration vector compared with gyro-free configuration based on only accelerometers. The inertial sensors are selected from the commercial microelectromechanical system devices to realize its low-cost applications.

The growing literature on complementarities has drawn attention to how the effects of different organizational structures, practices, and institutions are interdependent. Rather than one best way of organizing, complementarities suggest that the effectiveness of one organizational element may be dependent on the presence or absence of another particular element. Consequently, organizational arrangements often display “multiple equilibria” or what is known as equifinality, whereby multiple pathways may lead to the same or similar outcomes. While being a source of theoretical innovation, the configurational nature of complementarities has posed a number of challenges. This chapter reviews the emerging literature on complementarities to identify a series of conceptual challenges related to understanding complementarities as organizational configurations, and examines the methodological challenges in studying how such elements combine to produce joint effects on performance. The chapter argues that new set-theoretic methods using Qualitative Comparative Analysis (QCA) may present a very useful methodological alternative to studying complementarities. The chapter illustrates this potential by re-analyzing past work by Aoki, Jackson, and Miyajima (2007) on relationships between ownership structure, board structure, and employment practices of listed firms in Japan to show evidence of complementarities associated with hybrid configurations that combine market and relational forms of organization.

Design errors in an airport passenger building can be extremely costly. Failure to plan may result in configurations and systems that are inappropriate for the future. The performance of an optimal building configuration depends to a large extent on the kind of technology provided for the transportation of passengers and baggage. Poorly selected technology can undermine the operational efficiency of a good configuration and vice versa. With massive growth in air travel and the scale of modern passenger buildings, more reliance will be placed on transport technology to achieve acceptable walk distances and travel times. Therefore it is critical to consider in the overall design strategy how a particular building configuration and its associated technology will perform under conditions of change. Good design practice dictates that performance be assessed using multiple criteria over a broad range of possible conditions. The difficulty in predicting future conditions makes the selection of a robust system critical to the long‐term success of an airport. This paper examines the various systems available and concludes that different system combinations are appropriate for airports with different levels of passenger throughput.

This study examines the interplay of formal types of control (input, behavior and outcome) exercised on municipally owned corporations (MOCs). It further investigates whether particular informal contingencies (trust and interdependence) predict affiliation to the derived municipal control configurations.

The paper applies an exploratory cluster analysis based on survey data from 243 top-level managers of German MOCs. It then investigates the clustered municipal control configurations using binomial logistic regression.

The exploratory analysis reveals four municipal control configurations: (1) input-dominated control, (2) outcome-dominated control, (3) mixed input/outcome control and (4) “neglect of formal control”. As expected, both of the informal contingencies demonstrate strong predictive power. More precisely, trust increases the likelihood of belonging to the dominant outcome control cluster and interdependence increases the likelihood of belonging to the mixed input/outcome control cluster. Surprisingly, the neglect of formal control cluster is characterized by low trust and low interdependence.

The study sheds light on the widely assumed but understudied interplay of different formal controls in hybrid governance settings. Furthermore, the analysis stresses the importance of trust and interdependence when explaining hybrid control configurations.

Electronic components’ efficiency is the cornerstone of technology progress. The cooling process used for electronic components plays a main role in their performance. Embedded high-conductivity material and provided microchannel heat sink are two common cooling methods. The former is expensive to implement while the latter needs micro-pump, which consumes energy to circulate the flow. The aim of this study is providing a new configuration and method for improving the performance of electronic components.

To manage these challenges and improve the cooling efficiency, a novel method named Hybrid is presented here. Each method's performance has been investigated, and the results are widely compared with others. Considering the micro-pump power, the supply of the microchannel flow and the thermal conductivity ratio (thermal conductivity ratio is defined as the ratio of thermal conductivity of high thermal conductivity material to the thermal conductivity of base solid), the maximum disk temperature of each method was evaluated and compared to others.

The results indicated that the Hybrid method can reduce the maximum disk temperature up to 90 per cent compared to the embedded high thermal conductivity at the same thermal conductivity ratio. Moreover, the Hybrid method further reduces the maximum disk temperature up to 75 per cent compared to the microchannel, at equivalent power consumption.

The information in this research is presented in such a way that designers can choose the desired composition, the limited amount of consumed energy and the high temperature of the component. According to the study of radial-hybrid configuration, the different ratio of microchannel and materials with a high thermal conductivity coefficient in the constant cooling volume was investigated. The goal of the investigation was to decrease the maximum temperature of a plate on constant energy consumption. This aim has been obtained in the radial-hybrid configuration.

A hybrid-electric unmanned aerial vehicle (HE-UAV) model has been developed to address the problem of low endurance of a small electric UAV. Electric-powered UAVs are not capable of achieving a high range and endurance due to the low energy density of its batteries. Alternatively, conventional UAVs (cUAVs) using fuel with an internal combustion engine (ICE) produces more noise and thermal signatures which is undesirable, especially if the air vehicle is required to patrol at low altitudes and remain undetected by ground patrols. This paper aims to investigate the impact of implementing hybrid propulsion technology to improve on the endurance of the UAV (based on a 13.6 kg UAV).

A HE-UAV model is developed to analyze the fuel consumption of the UAV for given mission profiles which were then compared to a cUAV. Although, this UAV size was used as reference case study, it can potentially be used to analyze the fuel consumption of any fixed wing UAV of similar take-off weight. The model was developed in a Matlab-Simulink environment using Simulink built-in functionalities, including all the subsystem of the hybrid powertrain. That is, the ICE, electric motor, battery, DC-DC converter, fuel system and propeller system as well as the aerodynamic system of the UAV. In addition, a ruled-based supervisory controlled strategy was implemented to characterize the split between the two propulsive components (ICE and electric motor) during the UAV mission. Finally, an electrification scheme was implemented to account for the hybridization of the UAV during certain stages of flight. The electrification scheme was then varied by changing the time duration of the UAV during certain stages of flight.

Based on simulation, it was observed a HE-UAV could achieve a fuel saving of 33% compared to the cUAV. A validation study showed a predicted improved fuel consumption of 9.5% for the Aerosonde UAV.

The novelty of this work comes with the implementation of a rule-based supervisory controller to characterize the split between the two propulsive components during the UAV mission. Also, the model was created by considering steady flight during cruise, but not during the climb and descend segment of the mission.

The discussion about public sector performance is still present today, despite the profound research that has already tried to address this subject. Furthermore, theory links negative effects on organizational performance with increased levels of organizational complexity. However, literature thus far did not succeed to put forward a successful theory that explains why and how public organizations became increasingly complex. To answer this question, we argue that increased organizational complexity can be explained by viewing public organizations as the hybrid result of different institutional logics, which are shaped by various management views. However, former research mainly concentrated on the separate study of management views such as traditional public management (TPM), NPM, and post-NPM. Although appealing, research that approaches hybridity from this perspective is fairly limited.

We conducted a literature review in which we studied 80 articles about traditional public management, NPM, and post-NPM.

We found that these management views essentially differ on the base of three fault lines, depending on the level of the organizational culture. These fault lines, according to the management view, together result in nine dimensions. By combing dimensions of the different management views, we argue that a public organization becomes hybrid. Furthermore, in line with findings of contingency theory, we explain the level of hybridity might depend on the level of tight coupling for a given organization. Finally, we developed propositions that explain hybridity as the result of isomorphic forces, organizational change, and organizational resistance to change and that link hybridization with processes of selective coupling.

The value of this chapter lies in its real-life applicability.

A growing response in the development of hybrid composites to conquer the deficiency of neat composites has provoked doing this work. Thermoplastic Polycarbonate material offers better impact toughness with low structural weight. There is a little/no information available over the selected sandwich hybrid composite prepared from woven E-Glass and polycarbonate sheet. The purpose of this paper is to understand the response of the novel hybrid structure under tensile, flexural, interlaminar shear and impact loading conditions.

The hand-layup technique is used for fabricating the hybrid composites in the laminate configuration. The hybrid composites are prepared with a total fiber content of 70 percent weight fractions. The effect of the percentage of reinforcement on mechanical properties is evaluated experimentally as per American society for testing materials standard test methods. The damaged mechanisms of failed samples and fractured surfaces are well analyzed using vision measuring system and scanning electron microscopy.

A decline in densities of hybrid composites up to 22.5 percent is noticed with reference to neat composite. An increase in impact toughness up to 40.73 percent is marked for hybrid laminates owing to the ductile nature of PC. Delamination is identified to be the major mode of failure apart from fiber fracture/pull-out, matrix cracking in all the static loading conditions.

The response of novel hybrid composite reported has been explored for the first time in this paper. The outcome of experimental work revealed that hybridization offered lightweight structures with improved transverse impact toughness as compared to conventional composite.