Controlling a supplier’s subcontracting decisions through contractual enforcement or economic incentives

Suppliers often subcontract part of their workload to other suppliers, and manufacturers might suffer severe consequences if they do not anticipate their suppliers’ incentives to subcontract. In this paper, we study the case where a manufacturer outsources two tasks to a top-tier supplier. The manufacturer must decide whether it should design a contract that enforces that the different tasks are completed by the appropriate suppliers, and when it is preferable to use economic incentives to manipulate the top-tier supplier’s subcontracting behaviour. We find that when the cost difference between suppliers of different tiers is small and the correlation between the risks associated with the two tasks is minimal, the manufacturer can benefit from designing a contract that ensures the preferred subcontracting behaviour, if the cost of enforcing such a contract is not too high. However, when such enforcement cost is substantial, the manufacturer might be better off manipulating the top-tier supplier’s economic incentives.     

A flexible costing system for flexible manufacturing systems using activity based costing

Flexible manufacturing systems (FMSs) are designed to integrate the flexibility of job shops and the efficiency of mass production systems. Product costing methods have to adapt to this new technological environment. On one hand, the high production overhead cost of these systems requires a special attention to overhead allocation. On the other hand, the constantly changing setup configuration and production plans require a constant recalculation of overhead allocation and an a priori estimation of the expected production cost. This paper introduces the concept of flexible costing in FMSs, and proposes a method that modifies the overhead allocation based on the results of the production plan and on the simulated performance of the process. This approach is illustrated with some numerical examples.     

A heuristic based on Vogel's approximation method for sequencing mixed-model assembly lines

Sequencing mixed-model assembly lines is a well researched topic in the literature. However, many methods that have been developed to solve this problem fail to cope with either the large size or the specific characteristics of real-life problems. In this paper, a heuristic is proposed that is derived from Vogel's approximation method for transportation planning. The heuristic is able to handle large and supposedly difficult problem instances. Sophisticated test scenarios considering real-life aspects were generated to evaluate the performance of the heuristic for realistic problem instances. It is shown that the proposed heuristic significantly outperforms priority rule-based methods and requires only reasonable computational effort.     

Effect of glass fillers in Cu2ZnNb2O8 ceramics for advanced microwave applications

The effect of glass addition on sintering temperature and microwave dielectric properties of Cu₂ZnNb₂O₈ (CZN) is investigated for possible low temperature co-fired ceramic (LTCC) application. The CZN ceramic was prepared by the solid-state ceramic route. The phase formation, microstructure and elemental composition of the ceramics were studied using X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy and Energy Dispersive Analysis. The CZN sintered at 975 °C/4 h has ?_r = 15.2, tan δ = 0.0007 (at 5.1 GHz) and τ_f of −98 ppm °C⁻¹ and CTE = 1.9 ppm °C⁻¹. The addition of LBS and LMZBS glasses lowered the sintering temperature of CZN to below the melting point of silver. The 1 wt% LBS added CZN sintered at 935 °C/4 h had ?_r = 14.7, tan δ = 0.001 (at 5.1 GHz), τ_f = −19 ppm °C⁻¹ and CTE = −0.6 ppm °C⁻¹. The addition of 0.7 wt% LMZBS to CZN and sintered at 935 °C/4 h had ?_r = 14.8, tan δ = 0.002 (at 5.1 GHz), τ_f = −39 ppm °C⁻¹ and CTE = −0.9 ppm °C⁻¹.     

Overview: Status of the Microwave-Based Automotive Catalyst State Diagnosis

The oxygen loading degree in TWCs, the amount of stored ammonia in SCR catalysts, the NO_x loading degree in LNTs, or the soot loading of DPFs play a key role in automotive exhaust gas aftertreatment. Today’s methods determine the catalyst state indirectly. They utilize gas sensors installed up- or downstream of the catalysts and the catalyst state is inferred from the sensor signals. This overview reports on the status of an alternative approach based on the interaction of electromagnetic microwaves with the catalyst material. Since the catalyst state is strongly correlated with the electrical properties of the catalyst material itself, this concept shows a great potential.     

Measuring motion with kinematically redundant accelerometer arrays: Theory,simulation and implementation

This work presents two schemes of measuring the linear and angular kinematics of a rigid body using a kinematically redundant array of triple-axis accelerometers with potential applications in biomechanics. A novel angular velocity estimation algorithm is proposed and evaluated that can compensate for angular velocity errors using measurements of the direction of gravity. Analysis and discussion of optimal sensor array characteristics are provided. A damped 2 axis pendulum was used to excite all 6 DoF of the a suspended accelerometer array through determined complex motion and is the basis of both simulation and experimental studies. The relationship between accuracy and sensor redundancy is investigated for arrays of up to 100 triple axis (300 accelerometer axes) accelerometers in simulation and 10 equivalent sensors (30 accelerometer axes) in the laboratory test rig. The paper also reports on the sensor calibration techniques and hardware implementation.     

Towards robotic assistants in nursing homes: Challenges and results

This paper describes a mobile robotic assistant, developed to assist elderly individuals with mild cognitive and physical impairments, as well as support nurses in their daily activities. We present three software modules relevant to ensure successful human–robot interaction: an automated reminder system; a people tracking and detection system; and finally a high-level robot controller that performs planning under uncertainty by incorporating knowledge from low-level modules, and selecting appropriate courses of actions. During the course of experiments conducted in an assisted living facility, the robot successfully demonstrated that it could autonomously provide reminders and guidance for elderly residents.     

Electrodeposited and selenized (CuInSe2) (CIS) thin films for photovoltaic applications

In the present communication, the authors report results on the characterization of electrodeposited and selenized (CuInSe₂) (CIS) thin films. The selenization process was carried out using a technique called chemical vapor transport by gas (CVTG). The precursors as well as selenized films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron microprobe analysis (EPMA). The film stoichiometry improved after selenization at 550°C. The films were formed with a mixed composition of the binary as well as the ternary phases.     

Synthesis and study of properties of new oligoesters based on soybean oil as potential poly(vinyl chloride) plasticizers

New compounds as potential poly(vinyl chloride) plasticizers based on soybean oil and oligoesters of adipic acid and different glycols by one-pot transesterification are synthesized. In the first step of the plasticizer synthesis oligoesters of adipic acid and diethylene glycol, triethylene glycol, or dipropylene glycol are synthesized, and then in situ in the second step, a defined amount of soybean oil is introduced. By degradation of soybean oil with oligoesters, and transesterification reaction, different compounds are obtained. Their physicochemical properties are determined by NMR, SEC, DSC, TGA, and volatility analyses. The properties of synthesized plasticizers are compared with commercial products: monomeric (DEHP) and aliphatic oligoster of adipic acid and 1,3-butanediol (H-1).