Inspecting the Achilles heel: a quantitative analysis of 50 years of family business definitions

Despite numerous attempts by academics from many disciplines and various regional contexts, there is still no agreement on a definition of family business. Subjecting 258 definitions found in work published over the past 50 years (1964–2013) to the bibliometric techniques of consensus and co-word analysis to uncover intellectual structure, we identify the key terms used to underpin the concept of family business and to track the progress made towards consensus on its definition. We find an emergence of definitional key terms by which scholars attempt to clarify the concepts of family and family business, and growing agreement of what criteria should be met in framing a definition. This study contributes to the literature by offering a synthesis of what constitutes a family business, as well as a systematic and quantitative analysis of its evolution over a half century of research. It also shows how bibliometric tools can be used to shed light on fields where definitional ambiguity persists.     

Design and analysis of turnover platform for welding robot北大核心CSCD

A turnover platform for welding robot was designed for the application of welding robot with lower accuracy requirement, which was of low cost and higher position accuracy. In this turnover platform, the pneumatic motor was used as the power output, and the indexing mechanism with high accuracy was the transmission system with high transmitting ratio based on worm and wheel. The position information was acquired by using the photoelectric encoder, and the turnover motion with high accuracy was realized through the closed-loop controller. Simulation results showed that the maximum speed of the welding platform approached 14 r/min, and the platform could meet the requirements of most welding products. Such a turnover platform can offer the application program of the welding robot with low cost for the middle and low level products, and reduce the cost of welding robot and improve welding productivity.     

Design and analysis of longitudinal–flexural hybrid transducer for ultrasonic peen forming

Ultrasonic peen forming (UPF) is an emerging technology that exhibits great superiority in both its flexible operating modes and the deep residual stress that it produces compared with conventional plastic forming methods.Although ultrasonic transducers with longitudinal vibration have been widely studied,they have seldom been incorporated into UPF devices for machining in confined spaces.To meet the requirements of this type of machining,a sandwich-type piezoelectric transducer with coupled lon...     

Modeling of TES X-Ray Microcalorimeters with a Novel Absorber Design

We have successfully modeled our new TES (transition-edge sensor) X-ray microcalorimeters with a novel X-ray absorber design that is suitable for close-packed array with high quantum efficiency. We have determined device parameters that reproduce complex impedance curves and noise spectra throughout the transition. Observed pulse height, decay time and baseline energy resolution were in good agreement with simulated results using the same parameters.      

Performance analysis of open general queuing networks with blocking and feedback

Queuing network models have been extensively used for performance evaluation in many modern manufacturing and communication systems. The phenomenon of feedback reflects many practical situations, e.g. reworking in the production systems. However, existing research on open queuing network with feedback mainly concentrates on the models with infinite buffers or the models with finite buffers but exponentially distributed inter-arrival and service times. Research on open queuing networks with finite buffers, feedback and general inter-arrival and service times has not been reported. In this paper, a Rate Iterative Method embedded with the Generalised Expansion Method, is proposed for modelling this type of queuing network. System performance measures include the mean throughput, work-in-process and sojourn time all calculated by the proposed method. The accuracy and the efficiency of the proposed method are tested by comparing the results with other methods or simulation results from the experiments. Finally, a case study of a practical production system used in the manufacturing industry is studied and illustrates the applications of the proposed method. The results in this paper can be used as a basis for system design analysis and resource planning.     

Performance of TES X-ray Microcalorimeters with a Novel Absorber Design

Superconducting transition-edge sensor (TES) microcalorimeters have demonstrated the Constellation-X requirements for spectral resolution, speed, and pixel size in a close-packed geometry. We will present our recent breakthrough energy resolution with sensors that have all gold and bismuth-gold absorbers. This has been enabled by cantilevered absorbers that make contact to the TES only in regions that are not part of the active thermometer. With this approach, rapid thermalization of the x-ray energy is achieved and interaction between the absorber and TES sensor films is avoided. This design allows us to obtain uniform high performance and is compatible with large-format, high fill-factor arrays. We will discuss this design, the results we have achieved in 8×8 arrays of these pixels, and the dependence of the performance on the geometry of the absorber contact area and on stress within the sensor.      

Design of the Cryogen-Free Cryogenic System for the CUORE Experiment

We present here the final design of the cryogenic system where the CUORE detector will be installed in 2010. It is a large cryogen-free cryostat cooled by pulse tubes and by a high-power dilution refrigerator. To avoid radioactive background, about 15000 kg of lead will be cooled to below 1 K and only few construction materials are acceptable. The detector assembly will have a total mass of about 1500 kg and must be cooled to less than 10 mK in a vibration-free environment. We discuss the adopted technical solutions, the results of the preliminary thermal analysis of the system, and its expected performance.      

Biomimetic Design and Test of Composite Materials

A series of superior properties will make composites the most important structural materials in thenext century.But they are difficult to design owing to the complexity of structure and processing.Biomaterials had been naturally selected and evolved for millions of years,a great variety of their ra-tional composite structures could be taken as our reference in the biomimetic design of compositematerials.There are many difficult problems in the current study on composite materials such as:brittleness of continuous fibers and difficulties in interface design;easy pull-out of short fibers frommatrix causing failure in reinforcing;being less easy in selecting the aspect ratio of whiskers and dif-ficulties in finding the way of toughening composites of ceramic matrices as well as the way of heal-ing inner damages.After describing the distinct composite features,the functional adaptability andself-healing ability of biomaterials,several examples o.f biomimetic design of composite materialshave been listed in this paper:the optimum design of composites simulating bamboo structure;thefine structure of bamboo fibers;the dumb-bell model simulating animal bone;the model on thepull-out of fiber with fractal-tree structure and some tentative works on the healing of inner damagein composite materials The methodology of biomimetic design and its future have been given at theast part of this paper.     

Design and analysis for a delay‐bounded fair queueing algorithm

Abstract

In this paper, we propose a fair resource reservation and scheduling algorithm for delay‐bounded services. User applications initiate the requests by specifying the tolerable delay and priorities. Packets are scheduled according to the requirements negotiated during the resource reservation phase. Instead of tracking the fair utilization before the packet can be served in WFQ, the bandwidth share is monitored after the packet is sent. This approach can significantly reduce the computational complexity resulting from WFQ while maintaining the long‐term fairness. Examples and simulations are illustrated to show the performance difference from WFQ.     

Design parameters of part-ordering devices Design parameters selection and ordering of part-orienting devices†

We study the design problem of part-orienting systems which are often employed in many manufacturing environments to orient parts for assembly or to perform operations. A part-orienting system is composed of a number of orienting devices. The problem of selecting proper design parameters for the devices and of serially ordering them to make up the system is addressed in this paper. The problem is illustrated through a real example. Heuristic algorithms have been developed and computer experiments have been performed to evaluate their relative performances.     

Thermal stability analysis of Cu-11.8 wt%Al milled samples by TEM and HT-XRD

In this work, the thermal stability of two samples of Cu-11.8 wt%Al obtained by different milling processes is analyzed. Several TEM techniques were used and HT-XRD experiments performed to determine the crystal structure and the morphological microstructure of the samples obtained during different heat treatments. The heat treatments were: quenching from 850 °C to room temperature and two consecutive calorimetric runs at 5 °C/min. After the quenching,α₂ is the major phase observed, reaching 95 mass%. The remaining 5 mass% consisted of martensitic phases: one sample had γ′, a hexagonal structure, and the other β₁′, a rhombohedral structure. During the first calorimetric run, the sample containing the γ′ phase exhibited a calorimetric event and the sample containing the β₁′ phase did not. The calorimetric event is attributed to the austenitic transformation γ′ → β₁. The lack of calorimetric event in the sample containing the β₁′ is associated with the inhibition of the transformation β₁′ → β₁ because of the precipitation of the γ₂ phase. Finally, the absence of a calorimetric event in the second run with the first sample is associated with the retransformation to β₁′ instead to γ′ phase during cooling of the first calorimetric run. These studies determined that the first sample is a better candidate than the second sample to produce a shape memory alloy after thermo-mechanical treatments of the milled powders.     

Design and Fabrication Highlights Enabling a 2 mm, 128 Element Bolometer Array for GISMO

The Backshort-Under-Grid (BUG) superconducting bolometer array architecture is intended to be highly versatile, operating over a large range of wavelengths and background conditions. To validate the basic array design and to demonstrate its applicability for future kilopixel arrays, we will demonstrate a 128-element bolometer array optimized for 2 mm wavelength using a new Goddard Space Flight Center instrument, GISMO (Goddard IRAM Superconducting 2-Millimeter Observer). The design considerations unique to GISMO and laboratory experimental results will be discussed.      

Role of Coexistence of Superconductivity and Paramagnetism in Magnetostriction of High-T c Superconductors

Total magnetostriction in the superconducting state for high T _c superconductors has been separated into critical state and paramagnetic components in terms of a H(x) dependent magnetic flux density. We show that the paramagnetic part is χ(2+χ)〈H(x)²〉, where χ is paramagnetic susceptibility. We have reproduced successfully ΔL/L−H _a curves measured by de la Fuente et al. (Phys. C 244:214, [1995]), in which they clearly observed coexistence of superconductivity and paramagnetism, employing the concepts presented in this work.      

Vibration analysis of stepped rectangular plates using the extended Kantorovich method

In this study, vibration behaviors of stepped plates are investigated based on the variational principle of minimum total energy and the extended Kantorovich method. The out-of-plane displacement is represented by a separable function of parameters x and y. A set of governing equations, boundary conditions, and continuity conditions in the form of ordinary differential equations are derived from the energy condition. The natural frequency and out-of-plane displacement function can be determined numerically from the derived equations and conditions. Solutions from the proposed approach are in good agreement with results from past studies and those of the finite element method.     

Comprehensive exploration of urban health by bibliometric analysis: 35 years and 11,299 articles

This paper aims to evaluate the health issues related to urbanization and get an overview of urban health with the bibliometric approach, the powerful tool in quantitatively macroscopic analysis across multiple disciplines. A total of 11,299 articles and 5,579 Medical Subject Headings (MeSH) terms from the year 1978–2012 were retrieved by searching PubMed/MEDLINE using MeSH term “urban health”. The bibliographic information was analyzed to summarize the overall research characteristics. MeSH terms were sorted by their normalized frequency. Top 10 % of the high-frequency MeSH terms were classified into categories (physical environment, health effects, social environment and counter-measures) and analyzed. We investigated the themes and their tendency of the corresponding categories by co-occurrence word (co-word) and regression analysis. We concluded and elaborated nine themes of physical environment, ten themes of health effects, three themes of social environment and four themes of counter-measures in urban health, as well as the main themes in five representative countries (USA, India, China, South Africa and Japan). We present a data-based overview of the issues in urban health, as reference for further researchers.     

Design,analysis and application of high set-up ZVT DC–DC converter with direct power transfer

In this paper, a new snubber cell for soft switched high set-up DC–DC converters is introduced. The main switch is turned on by zero-voltage transition and turned off by zero-voltage switching (ZVS). The main diode is turned on by ZVS and turned off by zero-current switching. Besides, all auxiliary semiconductor devices are soft switched. Any semiconductor device does not expose the additional current or voltage stress. The new snubber transfers some of the circulation energy to the output side when it ensures soft switching for main semiconductor devices. Thus, the current stress of auxiliary switch is significantly reduced. Besides, the total efficiency of converter is high due to the direct power transfer feature of new converter. A theoretical and mathematical analysis of the new converter is presented, and also verified with experimental set-up at 500 W and 100 kHz. Finally, the overall efficiency of new converter is 97.4% at nominal output power.     

Static and dynamic scaling of semiflexible polymer chains—a molecular dynamics simulation study of single chains and melts

A molecular dynamics study of the effect of increasing molecular chain stiffness on the dynamic properties of single linear chains and polymer melts is presented. The chain stiffness is controlled by a bending potential. By means of a normal mode analysis the systematic crossover behavior of coarse-grained linear polymer systems from Rouse modes to bending modes with increasing mode number p is presented systematically for the first time via simulation data. The magnitude and the onset of the region where crossover behavior occurs is investigated in dependence of a systematic variation of the chains’ persistence lengths. For long wavelength modes the well-known p ⁻² behavior is observed which represents the Rouse scaling, whereas for the bending modes one observes a distinct p ⁻⁴ scaling of the mean square mode amplitudes and the relaxation times. Additionally, the effect of this crossover behavior on the monomer dynamics given by their mean square displacements is investigated. The findings are contrasted with previous simulation studies of semiflexible chain behavior and it is shown that those studies—due to too small persistence lengths L _p —were actually limited to the crossover regime where both, Rouse and bending modes contribute to the chain dynamics, and no distinct p ⁻⁴ scaling can be observed. Using an expansion of the monomer position vector, a simple theory of the observed scaling behavior is proposed which allows for deriving analytic expressions that describe the presented simulation data very well.     

Aerodynamic design and analysis of a 10 kW horizontal-axis wind turbine for Tainan,Taiwan

The purpose of the present study is to develop a small-scale horizontal-axis wind turbine (HAWT) suitable for the local wind conditions of Tainan, Taiwan. The wind energy potential was first determined through the Weibull wind speed distribution and then was adapted to the design of the turbine blade. Two numerical approaches were adopted in the design and analysis of the HAWT turbine blades. The blade element momentum theory (BEMT) was used to lay out the shape of the turbine blades (S822 and S823 airfoils). The geometry of the root region of the turbine blade was then modified to facilitate integration with a pitch control system. A mathematical model for the prediction of aerodynamic performance of the S822 and S823 airfoils, in which the lift and drag coefficients are calculated using BEMT equations, was then developed. Finally, computational fluid dynamics (CFD) was used to examine the aerodynamic characteristics of the resulting turbine blades. The resulting aerodynamic performance curves obtained from CFD simulation are in agreement with those obtained using BEMT. It is also observed that separation flow occurred at the turbine blade root at the tip speed ratios of 5 and 7.     

Comparison of multiple prompt γ-ray analysis and prompt γ-ray analysis for the elemental analysis of geological and cosmochemical samples

Multiple prompt γ-ray analysis (MPGA) and conventional neutron-induced prompt γ-ray analysis (PGA) are nondestructive analytical methods for bulk chemical compositions, and their analytical capabilities were compared for elemental analyses of geological and cosmochemical samples. Detection sensitivities of PGA are often restricted by poor signal-to-noise ratios and interferences from different origins. MPGA can substantially reduce the background level, especially for hydrogenous samples, relative to PGA, which opens up a possibility to use lower energy prompt γ-rays of some trace elements. Although it is one of the major constituent elements of rock samples, Mg is hard to be determined by PGA. With MPGA, Mg contents could be determined with reasonable consistency with their corresponding recommended values in geological and cosmochemical samples by carefully selecting suitable coincident prompt γ-ray energy pairs without interference correction. MPGA was applied to a hydrogenous meteorite, Ivuna, which contains H at 2% mass level. MPGA detection limits for most of the elements studied can be reduced up to 1 order of magnitude when compared with PGA detection limits under the present experimental conditions.