518 research outputs found
Movement generation and trip distribution for freight demand modelling applied to city logistics
The
quantification of the freight movements disaggregated by supply chain occurring in each traffic
zone for the urban delivery of goods and that of the corresponding Origin
-
Destination trip tables is
essential to evaluate the effects of any city logistic poli
cy in terms of vehicle congestion and polluting
emissions through the assignment of truck flows on the road network.
In this paper we propose two innovative demand models: the first one for movement generation, the
second one for trip distribution. The mov
ement generation is addressed through an extension of the
category index model, which takes into account the hierarchy in the classification system of the economic
activities, thus avoiding
aggregating
the many existing classification codes into pre
-
specif
ied groups. The
trip distribution is addressed through an adaptation of the gravity model, which takes into account that
deliveries are organized in tours.
This approach has been successfully applied to the case of Emilia
-
Romagna Region in Italy, where an
extensive campaign of surveys has permitted to calibrate both models for several towns and cities with
various dimensions and vocations
UPDATED MODIFICATIONS ABOUT SPIN BIOREACTOR
This paper carries out the implementation of a Raspberry-controlled bioreactor. The previously proposed model was analyzed and assembled to determine its effectiveness and solutions to the problems that emerged during construction were highlighted. The realization of the project is possible, as now some elements can be replaced. Overall, these modifications on this miniature rotary bioreactor make the apparatus exceptionally easy to build following designated guidelines. This updated device is susceptible to various experiments of varying lengths without having to worry about possible malfunctions such as unexpected events or hardware and software problems
Microfluidic Live-Imaging Technology to Perform Research Activities in 3D Models
Morphological dissimilarity and its evolution over time are one of the most unexpected variations found when comparing cell cultures in 2D and 3D. Monolayer cells appear to flatten in the lower part of the plate, adhering to and spreading in the horizontal plane while not extending vertically. Consequently, cells developed in two dimensions have a forced apex-basal polarity. Co-cultivation and crosstalking between multiple cell types, which control development and formation in the in vivo counterpart, are possible in 3D cultures. With or without a scaffold matrix, 3D model culture may exhibit more in vivo-like morphology and physiology. 3D cultures mimic relevant physiological cellular processes, transforming them into one-of-a- kind drug screening platforms. The structures and dynamics of regulatory networks, which are increasingly studied with live-imaging microscopy, must be considered to help and guarantee the functional maintenance of a 3D structure. However, commercially available technologies that can be used for current laboratory needs are minimal, despite the need to make it easier to acquire cellular kinetics with high spatial and temporal resolution, in order to improve visual efficiency and, as a result, experimentation performance. The CELLviewer is a newly developed multi-technology instrument that integrates and synchronizes the work of various scientific disciplines. The aim of this study is to test the device using two different models: a single Jurkat cell and an MCF-7 1 spheroid. The two models are loaded into the microfluidic cartridge for each experiment after they have been grown and captured in time-lapse for a total of 4 hours. The samples used are tracked under the operation of the optics after adaptive autofocus, while slipping inside the cartridge chamber and the 3D rotation was successfully obtained experimentally. The MitoGreen dye, a fluorescence marker selectively permeable to live cells, was then used to determine cell viability. To measure the model diameter, construct fluorescence intensity graphs along a straight line passing through the cell, and visualize the spatial fluorescence intensity distribution in 3D, Image J software was used
TSpack: a unified tabu search code for multi-dimensional bin packing problems
We present a computer code that implements a general Tabu Search technique for the solution of two- and three-dimensional bin packing problems, as well as virtually any of their variants requiring the minimization of the number of bins. The user is only requested to provide a procedure that gives an approximate solution to the actual variant to be solve
Models and bounds for two-dimensional level packing problems
We consider two-dimensional bin packing and strip packing problems where the items have to be packed by levels. We introduce new mathematical models involving a polynomial number of variables and constraints, and show that their LP relaxations dominate the standard area relaxations. We then propose new (combinatorial) bounds that can be computed in O(nlog n) time. We show that they dominate the other bounds, and establish their absolute worst-case behavior. The quality of models and bounds is evaluated through extensive computational experiment
- …