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.     

Theoretical investigation of a semiconductor ring laser driven by Chua’s oscillator

The modeling and numerical investigation of the dynamical behavior of a semiconductor ring laser (SRL) driven by Chua’s oscillator are reported. By increasing the coupling strength between the SRL and Chua’s oscillator at a fixed bias current, the SRL exhibits an intermittency route to anti-phase chaos. However, for a fixed value of the coupling strength, we report a period-doubling route to out-of-phase and anti-phase chaos when varying one of the parameters of the Chua’s oscillator are reported. We also demonstrate that a SRL driven by the chaotic output of Chua’s oscillator generates a more complex chaos compared to the one found in a SRL subject to a sinusoidally modulated current. This new way of modulation of semiconductor lasers would not only bring a general benefit in the physical equipment and reduce their cost but could have an impact for some relevant engineering applications.     

Free damped vibrations of a viscoelastic oscillator based on Rabotnov’s model

Free damped vibrations of a linear viscoelastic oscillator based on Rabotnov’s model involving one fractional parameter and several relaxation (retardation) times are investigated. The analytical solution is obtained in the form of two terms, one of which governs the drift of the system’s equilibrium position and is defined by the quasi-static processes of creep occurring in the system, and the other term describes damped vibrations around the equilibrium position and is determined by the systems’s inertia and energy dissipation. The drift is governed by an improper integral taken along two sides of the cut of the complex plane. Damped vibrations are determined by two complex conjugate roots of the characteristic equation, which are located in the left half-plane of the complex plane. The behaviour of the characteristic equation roots as function of the system’s parameters is shown in the complex plane. Dedicated to the bright memory of Academician Yury N. Rabotnov.     

The inverse hockey stick effect: an empirical investigation of the fiscal calendar’s impact on firm inventories

We empirically investigate how manufacturers’ inventory decisions relate to the fiscal calendar. Although optimal firm inventories should depend on demand and supply, we find that the artificial accounting construct of the fiscal year frequently drives inventory dynamics. In an effort to manage earnings and cash flows (CFs) towards the fiscal year-end (FYE), firms significantly reduce their inventories in the fourth fiscal quarter only to increase their inventories in the next fiscal year. Using a sample of 4877 US manufacturing firms for the period 1990–2010, we find that inventories are 3.9–6.0% lower on average in the fourth fiscal quarter. In the analysis, we control for inventory theory-related factors that have been identified in prior literature. Because this pattern is the inverse of that observed for sales, we refer to this phenomenon as the inverse hockey stick effect. The effect holds for all three individual inventory types: raw materials, work in progress and finished goods. We find that inventory reductions in the fourth fiscal quarter are particularly substantial if firms have an incentive to beat CF targets. In contrast to our expectations, we do not find evidence that financial distress links to inventory reductions at the FYE.     

Coarse-Grained Interaction of a Fluid with a Physically-Patterned Solid Surface: Application to Nanodroplet Wetting

We derive coarse-grained potentials to describe the interaction of a physically adsorbed, fluid-phase atom with a solid surface that is patterned with an array of rectangular or cylindrical pillars. The coarse-grained potentials are used in molecular dynamics simulations to probe the wetting of a Lennard-Jones liquid droplet on various patterned solid surfaces. Our results, which indicate that surface patterning can significantly influence wetting, are in agreement with previous studies.     

Thermal Conductivity of a Molecular Crystal with Rotational Degrees of Freedom: Orientational Defect Scattering

Measurements of thermal conductivity of solid methane-deuteromethane solutions at equilibrium vapor pressure in the temperature range 1.2÷20 K are reported. The obtained dependences of thermal conductivity on temperature and concentration can be explained qualitatively assuming that the dominant mechanism of phonon scattering is connected with the interaction of phonons with the rotational motion of the molecules in all of the three orientational phases of the CH₄-CD₄ system. The contribution of the orientational defect scattering to the thermal conductivity is discussed in frame of the model of local changes in the moments of inertia of molecules.      

Measuring Young’s modulus of biological objects in a liquid medium using an atomic force microscope with a special probe

A special probe with a 5-μm-diameter ball fixed at the end is developed for an atomic force microscope (AFM), with the use of which it is possible to obtain more correct values of the Young’s moduli of biological objects in liquid media and eliminate the risk of damaging the sample surface. In particular, the AFM measurements with this probe in situ revealed an increase in the Young’s modulus of rat blood vessel under the action of chlorhexidine.     

Magnetic Forces Relaxation Step Change Characteristics of YBCO Bulk with Mechanical Impact Load over a NdFeB Guideway

Magnetic force relaxation of YBCO bulk above the NdFeB permanent magnet guideway (PMG) with impact load has been investigated. An experimental setup has been built using a single YBCO bulk and a symmetrical center NdFeB PMG. There are two experimental methods: the case of magnetic levitation force relaxation measuring perturbed with impact load in zero-field-cooling (ZFC); and the case of magnetic levitation and guidance force relaxation measuring synchronously perturbed with impact load in field-cooling (FC). The results show that there is magnetic levitation and guidance forces relaxation step change at the time of the impact load. Two times impact loads are applied for each method. The first step change range is much larger than the second one. The Bean critical model and Anderson–Kim theory are used to analyze it.     

Analysis of the possibility of an experimental refinement of boltzmann’s constant by a radiation-calorimetric method

The possibility of refining Boltzmann’s constant by an experimental determination of the value of the Stefan–Boltzmann constant using the resources of adiabatic calorimetry is considered.     

A path-following driver model with longitudinal and lateral control of vehicle’s motion

The use of closed-loop driver models is important for accurate vehicle simulations and in active safety systems evaluation. In this paper we present a combined longitudinal-lateral controller that is regulating the steering angle and throttle/brake levels by previewing the path ahead of the vehicle. The lateral steering controller is using, as input, the heading and position deviation between the vehicle and the road. The controller is using fixed gains with a simple gain scheduling based on the vehicle’s speed. The longitudinal speed controller is using the curvature of the path ahead of the vehicle to determine the appropriate velocity of the vehicle. The longitudinal-lateral controller is tested by driving a double-lane change (ISO 3888-2) and a lap around a racing track.     

Properties of iron under Earth’s core conditions: Molecular dynamics simulation with an embedded-atom method potential

Using an earlier proposed embedded-atom method potential, we have performed molecular dynamics simulations of the thermodynamic, structural, and diffusional properties of iron under Earth’s core conditions (temperatures of up to 5000 K and densities of up to 12.5 g/cm³). The results attest to spontaneous crystallization of liquid iron at certain parameters of state. We have derived equations of state for the liquid and solid phases and have calculated their heat capacities at constant pressure and temperature, thermal expansion coefficients, isothermal and adiabatic bulk moduli, and sound velocities under various conditions. In addition, we have calculated the heat of fusion of iron and the change in its molar volume on melting. The results agree with literature data. The self-diffusion coefficient of iron decreases linearly with increasing density, vanishes at the densities corresponding to the liquid-solid phase boundary, and is a roughly linear function of temperature.     

Towards optimal configuration of a manufacturer’s supply network with demand flexibility

Demand flexibility exhibits the degree to which customers are often willing to compromise on product features or performance levels for budgetary (reflected in price) or schedule (reflected in delivery) reasons. It is essential for a manufacturer to map demand flexibility into the supply side and investigate its impact on supply network configuration to maximise its total profit. This paper is among the first contributions that seek to address the challenge of optimal configuration of a manufacturer’s supply network that consists of raw material suppliers and contract manufacturers, considering demand flexibility and commonality among different product families. A new mixed integer programming model is developed to describe the characteristics of this problem. The objective was to maximise the manufacturer’s total profit subject to various operating constraints of the supply chain. In view of the complexity and non-deterministic polynomial-time (NP)-hard nature of the problem, a hybrid constraint programming and simulated annealing algorithm is proposed to solve the problem optimally. Extensive numerical studies are conducted to validate the effectiveness of the proposed model and the hybrid algorithm.     

Con Colbert’s Portrait: The Lives of a Photograph

The history of photography has generally been conceived of in terms of technical advances, aesthetics, genre or oeuvre. This article proposes that other histories become apparent when materiality is foregrounded. To support this proposition the study focuses primarily on one portrait photograph and its embedded history, which is evident in its shifts in material form. The photograph under consideration is of Cornelius, more familiarly known as Con Colbert, a minor figure in the Irish Rising of 1916. His memory came to exceed the life of a man, and to understand why this was the case it is necessary to focus on the mediated presence of his portrait image in a culture of remembrance. What Colbert’s portrait makes evident is that a photograph is a material object which carries a history in its transferences, display formats and layered meanings. Photographs do things, they have agency, are affective and, in turn, are effected by cultural needs and interpretation. In other words, it is proposed that a history of the photograph is embedded in the exchanges and uses to which it is put which cannot be separated out from choices of material form.     

Mechanical property of magnesium alloy sheet with hardening deterioration at warm temperatures and its application for failure analysis: Part II – failure analysis

The mechanical properties of a thin AZ31B Mg alloy sheet (with the thickness of 0.5 mm) were characterized for its anisotropy, temperature-dependent hardening (including its deterioration) and strain rate sensitivity based on simple tension test data measured at 100 °C, 150 °C, 200 °C, 250 °C, respectively, in Part I. As for anisotropy, simple tension tests were performed along three (rolling, transverse and in-between) directions to calibrate the Hill1948 yield function. As for temperature-dependent hardening, hardening as well as its deterioration (or softening) behavior observed beyond the uniform elongation limit was numerically characterized based on the inverse calibration method, in which strain rate sensitivity was also considered. The mechanical properties were confirmed to properly predict failure by strain localization for all the simple tension tests involved in the characterization procedure. Ultimately, the mechanical properties characterized in Part I were applied in Part II to analyze the failure by strain localization in the cross-shaped cup drawing tests developed as the benchmark problem for the NUMISHEET2011 conference [1]. The results showed that the mechanical properties with hardening deterioration properly predicted failure, while hardening without deterioration (obtained following the common practice) did not, confirming the importance of including the hardening deterioration in tensile property characterization, especially to predict forming failure by strain localization.     

Effective Width of the Free Flange of the Ship’s Wide Beam with an Axis Bend

Strength of Materials - The strain-stress state (SSS) of a free flange of a constant width of the typical ship thin-walled beam with a break of an axis of I-section at elastic deformation is...