Linear Optimization in Uncertain Environment: Sensitivity of the Solution to the Belief Degree

Uncertainty theory has been initiated in 2007 by Liu, as an axiomatically developed notion, which considers the uncertainty on data as a belief degree on the domain expert’s opinion. Uncertain linear optimization is devised to model linear programs in an uncertain environment. In this paper, we investigate the relation between uncertain linear optimization and parametric programming. It is denoted that the problem can be converted to parametric linear optimization problem, at which belief degrees play the role of parameters, and parametric linear optimization with its rich literature provides insightful interpretations. In a point of view, a strictly complementary optimal solution of problem is known for the belief degree [Formula: see text], as well as the associated optimal partition. One may be interested in knowing the region of belief degrees (parameters) where this optimal partition remains invariant for all parameter values (belief degrees) in this region. We consider the linear optimization problem with uncertain rim data, i.e., the right-hand side and the objective function data. The known results in the literature are translated to the language of uncertainty theory, and managerial interpretations are provided. The methodology is illustrated via concrete examples.

Soft Robotics in Body Assistance: An Intelligent Rehabilitation Device with Soft Continuum Actuation

In an effort to improve rehabilitation devices, the applications of soft robotics technologies to prosthetics and physical therapy was explored, particularly due to the benefits of the inherent properties of soft materials. A conceptual design for a soft robotics device prototype is proposed to assist with physical therapy for wrist tendonitis and arthritis, carpal tunnel syndrome, fractures and sprains, and compromised motor skills due to chronic stroke. The device assists in four motions that are commonly performed in wrist therapy: flexion, extension, and rotation (clockwise and counterclockwise) using soft pneumatic actuators to guide movements. The distinct directions were achieved by varying the lateral and radial strain limiting layers. The device uses embodied intelligence to make the device dynamically adaptable in real time, allowing for a customizable recovery process. A detailed model of the device was developed and the viability of the design was assessed using a suite of state-of-the-art simulation tools and limited hardware prototyping. Simulations were performed through integration of Rhinoceros 3D, Grasshopper 3D, Firefly, an Arduino microcontroller, biosensors, Python scripting, and visual parametric programming. Pressure and materials were simulated and tested in Simulia Abaqus and Autodesk Fusion 360. Several parametric variations were tried using simulations and the predictions revealed that rubber silicone at a pressure of 10 kiloPascals is the optimal choice.

Impact of Feeding Pattern on the Structure and the Economic Performance of Dairy Cow Sector

In dairy farms, the feeding cost, which includes the expenses for purchased feed but also the expenses for feed production, constitutes a very large part of production cost (more than 60%), which indicates the economic importance of the feeding strategy. This study discerns three different feeding strategies: landless farms only purchasing feed from markets (“Purchasing”), farms for which home-grown feeds stand for more than 10% of feeding costs (“Producing”) and farms with less than 10% home-grown feeds (“Multi-purpose”). Based on technical and economic data from 47 dairy cow farms in Greece, alternative scenarios of development of the dairy sector are determined taking into account the dependence on on-farm feed production. Through a parametric programming model, the study provides insights regarding the optimal structure of the system under different scenarios (changing availability of variable capital, changes in milk prices). The results indicate that “Purchasing” farms are the preferred option when variable capital is abundant and milk prices are satisfactory, while “Producing” are the ones surviving with milk prices significantly lower than the actual ones in Greece and European Union. “Multi-purpose” farms perform worse than the other two and are sidelined in both scenarios, as they do not seem to be able to specialize in the dairy enterprise or in crop production and thus to minimize costs.

Method to Investigate Multi-Axis Release Action of Ski Safety Bindings: A New Approach for Testing in Research and Development

The authors developed and elaborated on a new method to release ski bindings by utilizing an industrial robot to simulate release movement showing a spatial repeatability of ± 0.06 mm. The parametric programming of the release parameters gave free control while executing repeatable release tests. A series of different motion patterns were performed, on the one hand, to test the applicability of the setup to the simulation of motion patterns and, on the other, to check for the impact of the ski deformations like ski deflections within the range of −5 mm to −85 mm, on the safety bindings' release forces. As certain falling mechanisms are related to knee injury, which is the most common severe injury in alpine skiing, this testing method can be used to develop related displacement movements in future. This movements do not necessarily accord with the directional release mechanics of safety ski bindings. The authors specify the developed testing apparatus as device for force measurements in 3D with an accuracy of ± 0.5% in boot-sole-plane. The intention behind this development is to enable faster, more versatile and adaptive testing procedures in R&D.

Generating NURBS cladding and structures with parametric programming and BIM

The process of designing and building curvilinear architectures is still challenging. The use of multiple applications with distinctive design paradigms are unlikely to disappear. The interoperability used here was not only the conventional one. It was also ‘live’, in ‘real time’, with two of the applications involved opened and running simultaneously. A design workflow based on the use of form-forming applications connected via parametric programming to building information modeling, BIM, was proposed. The main objective was to facilitate designing and building curvilinear architectures and their supporting structures using simultaneously two different design paradigms. The tools needed in our research can be summarized as follows: NURBS Lofting for surface creation, contouring for modular slicing and structural axis grid definition, sweeping along axes for surface creation of the curved beams of I profile and paneling for the subdivision of curved surfaces into planar fractions. Parametric programming was used to automate sweeping along axes to generating curved I-beams and paneling to subdivide the NURBS surfaces into planar fractions. To the best of our knowledge, our major contribution resides in defining a workflow and developing new algorithms for facilitating designing NURBS surfaces and corresponding supporting structures through ‘live’ interoperability among different applications.