Vertically coordinated ties are purportedly effective responses to the uncertainties of fast-changing purchasing environments. Building on transaction costs arguments and related work in marketing, the authors analyze vertical coordination as a response to external uncertainty and show that its effectiveness is highly contingent on the magnitude of the safeguarding problem present. Indeed, its ...

In the conventional sliding mode control, a discontinuous switching control signal is applied. It makes the system invariant to parametric uncertainty and external disturbance, but also causes actuator chattering. This paper considers a tracking control of robot manipulators using a dynamic sliding mode control, where a global invariance is achieved and the resulting control signal is chatterin...

BACKGROUND Leukoaraiosis is defined as extracellular space caused mainly by atherosclerotic or demyelinated changes in the brain tissue and is commonly found in the brains of healthy older people. A significant association between leukoaraiosis and traffic crashes was reported in our previous study; however, the reason for this is still unclear. METHOD This paper presents a comprehensive eval...

Most high-performance organic solar cells involve bulk-heterojunctions in order to increase the active donor-acceptor interface area. The power conversion efficiency depends critically on the nano-morphology of the blend and the interface. Spectroscopy of the sub-bandgap region, i.e., below the bulk absorption of the individual components, provides unique opportunities to study interface-relate...

We analyze the nonequilibrium dynamics of single inextensible semiflexible biopolymers as stretching forces are applied at the ends. Based on different (contradicting) heuristic arguments, various scaling laws have been proposed for the propagation speed of the backbone tension which is induced in response to stretching. Here, we employ a newly developed unified theory to systematically substan...

OBJECTIVES The National External Quality Assessment (NEQA) program of Burkina Faso is a proficiency testing program mandatory for all laboratories in the country since 2006. The program runs two cycles per year and covers all areas of laboratories. METHODS All panels were validated by the expert committee before dispatch under optimal storage and transport conditions to participating laborato...

The implementation of Clinical Governance will require a redefinition of duties and accountability as a prerequisite to develop and achieve an overall improvement in clinical care through a culture of assessment and monitoring of quality. External Quality Assessment Schemes (EQAS) are the main tool enabling laboratories to measure the quality of their results; they must carefully assess and mon...

Group structure and cohesion along with their changes over time play an important role in the success of missions where crew members spend prolonged periods of time under conditions of isolation and confinement. Therefore, an objective system for unobtrusive monitoring of crew cohesion and possible individual stress reactions is of high interest. For this purpose, an experimental wireless group...

THIS paper aims at describing, illustrating, and interpreting the ocular lesions associated with onchocerciasis. The literature of onchocerciasis already includes many pictures of the ocular lesions. The paintingst and diagrams in this paper supplement those previously published and are intended to fill gaps in the existing literature. The accompanying text expresses the author's views on the i...

Coherence resonance occurring in semiconductor lasers with optical feedback is studied via the Lang-Kobayashi model with external nonwhite noise in the pumping current. The temporal correlation and the amplitude of the noise have a highly relevant influence in the system, leading to an optimal coherent response for suitable values of both the noise amplitude and correlation time. This phenomeno...