A Reconfiguration Algorithm for the Single-Driven Hexapod-Type Parallel Mechanism

This paper presents a hexapod-type reconfigurable parallel mechanism that operates from a single actuator. The mechanism design allows reproducing diverse output link trajectories without using additional actuators. The paper provides the kinematic analysis where the analytical relationships between the output link coordinates and actuated movement are determined. These relations are used next to develop an original and computationally effective algorithm for the reconfiguration procedure. The algorithm enables selecting mechanism parameters to realize a specific output link trajectory. Several examples demonstrate the implementation of the proposed techniques. CAD simulations on a mechanism virtual prototype verify the correctness of the suggested algorithm.

Manuel Ponce

Manuel María Ponce Cuéllar (b. Fresnillo, Zacatecas, 8 December 1882–d. Mexico City, 24 April 1948) is one of Mexico’s foremost composers and has been widely acknowledged as a pioneer of musical nationalism in his country. His prolific catalogue contains more than 300 compositions. A cultured man, he wrote over 200 essays on musical topics and was the founding editor of three influential music journals: Revista Musical de México (Mexico City, 1919–1920), Gaceta Musical (Paris, 1928–1929), and Cultura Musical (Mexico City, 1936–1937). On occasion, he used the anagrammed pen names Noé Mac Púlmen or Noé Mac Ulpmen. Polyglot and multifaceted, he undertook an array of activities: teacher, lecturer, researcher, editor, music critic, administrator, conductor, pianist, and composer. Ponce studied music in Mexico City, Bologna, Berlin, and in Paris at the École Normale de Musique with Paul Dukas. His eclectic style ranges from baroque, classical, and romantic to impressionistic, neoclassic, and neoromantic. Influences from the music of Spain, Cuba, and especially from Mexico are also found. Ponce first gained transnational exposure as the composer of the song Estrellita (1912). Subsequently, the quality and quantity of his guitar works, including the celebrated Concierto del sur (1940), became one of the single most important contributions to the literature of that instrument. Recent decades have witnessed an increase in scholarly texts on Ponce. Internationally known for his guitar works, that specific output has received widespread attention in editions, articles, and recordings. Fewer texts are to be found concerning the rest of his musical catalogue as well as on his writings. During his lifetime, abundant newspapers closely followed his career. Later, Ponce’s birth and death anniversaries have prompted bursts of publications. The present and future are promising as more performers and scholars around the world are getting drawn to the Mexican composer. Ponce married contralto Clema Maurel in 1917. They had no children. In 1936, Carlos Vázquez became Ponce’s piano student and, with time, one of his closest disciples and ultimately his heir. After Ponce’s demise, Clema, with the assistance of Carlos, worked tirelessly to preserve, edit, and disseminate the composer’s work. Following her passing, Carlos carried on with these endeavors for the rest of his life.

Mathematical model of the process of ultrafiltration concentration of secondary milk raw materials in tubular membrane devices with filtering elements of BTU 05/2 type

For the qualitative application of ultrafiltration processes for the concentration and purification of food solutions, both experimental studies and a mathematical description of the processes of the membrane separation process of solutions from the standpoint of the development of computational mathematical models are required. In this work, by analytical solution of equations, that is, by the method of finite differences, mathematical equations are solved. To obtain the system, the flow continuity equations, convective diffusion equations, Navier-Stokes equations and flow equations with boundary conditions were solved in order to build a mathematical model of the process of ultrafiltration protein concentration in cheese whey in the production of rennet cheeses. As a result of the analytical solution of the equations, a system of mathematical equations was obtained that allows one to construct a profile of changes in the flow rates of the solution along the cross-section of the intermembrane channel and to determine the protein concentration in cheese whey along the length of the tubular ultrafiltration element BTU 05/2 of industrial type. The obtained mathematical model makes it possible to theoretically describe the process of ultrafiltration protein concentration in cheese whey along the entire length of the membrane channel of the tubular element under laminar and transient regimes of solution flow. The resulting system of mathematical equations makes it possible to find the numerical values of the mass flow rate of cheese whey, make it possible to calculate the specific output flow when the transmembrane pressure changes and to calculate the concentration of solutes in the secondary milk raw materials on the left and right ultrafiltration membrane of the intermembrane channel. The adequacy of the developed mathematical model was carried out by comparing the calculated and experimental data on the specific output flow when the transmembrane pressure in the intermembrane channel changes from 0.1 to 0.25 MPa with ultrafiltration concentration of cheese whey. The deviation of the calculated data found by the mathematical model from experimental studies obtained on a semi-industrial tubular ultrafiltration plant BTU 05/2 using semipermeable membranes, in which the active layer is made of fluoroplastic, hemisulphone and polyethersulfone, did not exceed 10%.

Two-stream fusion edge detection network

This thesis introduces a method to combine static and dynamic features in a convolutional neural network (CNN) to produce a motion and object boundary prediction map. This approach provides the CNN with dynamic and static cues and information, thus improving its predictions. The spatial stream of the CNN learns to compute an object boundary prediction map from a single RGB frame, while the temporal stream learns to compute a motion boundary prediction map from the corresponding optical ow map. The streams are then combined through an encoder-decoder architecture, where the decoder learns to fuse the features from both streams to obtain a task specific output. The proposed method yields state-of-the-art results on a motion boundaries benchmark, and systematic improvements in object boundaries benchmarks over methods that solely rely on static features extracted from a single RGB frame.

Two-stream fusion edge detection network

This thesis introduces a method to combine static and dynamic features in a convolutional neural network (CNN) to produce a motion and object boundary prediction map. This approach provides the CNN with dynamic and static cues and information, thus improving its predictions. The spatial stream of the CNN learns to compute an object boundary prediction map from a single RGB frame, while the temporal stream learns to compute a motion boundary prediction map from the corresponding optical ow map. The streams are then combined through an encoder-decoder architecture, where the decoder learns to fuse the features from both streams to obtain a task specific output. The proposed method yields state-of-the-art results on a motion boundaries benchmark, and systematic improvements in object boundaries benchmarks over methods that solely rely on static features extracted from a single RGB frame.

On the Role of GNSS Receivers for Antenna Patterns and Parameter Estimations

<p>The precise processing of data derived by several global navigation satellite systems (GNSS) for global and regional networks relies on high-quality and calibrated equipment. Currently, an intensively discussed question in the IGS antenna working group is the best practice for publishing and distributing calibration values for receiver antennas for different systems and frequencies. There is the question of frequency band specific output of calibration values or system specific output, the magnitude of their differences and their impact the estimation parameters that are not yet assessed. We will address these points in our contribution.</p><p>Several studies performed and evaluated at our calibration facility demonstrate a systematic impact of the receiver and the implemented signal tracking concept. The expected magnitudes in GNSS processing lead to differences on the coordinate domain of a few millimetres on a short and well-controlled baseline for original observations or frequencies. These effects are superimposed and amplified when forming linear combinations of independent signals and frequencies, which, however, are essential for global GNSS processing tasks such as ionosphere-free linear combination in global GNSS networks.  These amplifications are critical as apparent biases in the coordinate and troposphere estimates are introduced with different magnitudes.</p><p>For this reason, we present a quality assessment for different antenna-receiver combinations and provide an in-depth analysis and comparison for the majority of available and existing systems, signals, frequencies and linear combinations. The data were recorded under well-controlled conditions and include GNSS data of more than one week for each of the analysed number of four geodetic and reference station grade antennas. The analysis of the different combinations of antenna-receiver configurations provides metrics for assessing the impact of the receivers on the multi-system GNSS processing and the determination of the geodetic estimates. Consequently, validation with theoretical and expected metrics derived through multiple linear combinations is investigated, with additional focus on coordinate and troposphere estimates. The analysis uses the concepts of relative (baseline processing) and absolute (precise point positioning, PPP) GNSS processing.</p>

ANALYSIS OF KINETIC CHARACTERISTICS OF BAROMEMBRANE AND ELECTROBARMEMBRANE SEPARATION OF AMMONIUM NITRATE SOLUTION

The paper presents a generalized analysis of literature data on the current-voltage, omics characteristics and electrical conductivity of membrane systems. Based on an analysis of the literature, it is noted that electrodialysis is a promising method for the separation of solutions for the production of ammonium nitrate. An analysis of literature revealed that the application of an external constant electric field to the membrane separation of solutions containing charge-transporting components (nitrate ions and ammonium ions) causes the directed transfer of cations and anions through the membranes. The studies revealed that with the baromembrane separation of the studied solutions with increasing transmembrane pressure, the specific output stream increases. This is due to an increase in the driving force of the process. For the OFAM-K anode membrane, with an increase in the current density, with the electrobaromembrane separation of the ammonium nitrate solution, the specific output stream decreases, which is associated with a change in the pH value of the acidified anode permeate. nd for the OPMN-P cathode membrane, the specific output stream increases with a change in the pH of the alkalized cathode permeate. A modified mathematical equation is proposed for theoretical calculation of the specific output stream and the retention coefficient of the OFAM-K and OPMN-P nanofiltration membranes. Experimental studies of membrane systems equipped with the anode OFAM-K and the near-cathode OPMN-P membranes from voltage and transmembrane pressure revealed that for the aqueous solution of ammonium nitrate there are two characteristic periods on the current-voltage, omics characteristics and electrical conductivity of the membrane system (the first period is beyond regime, dissociation of water (H+ and OH-) at the phase boundary with the advent of additional electric current carriers, the second is the degradation of the active layer of a semipermeable membrane). When studying the current-voltage characteristics of a membrane system equipped with an anode OFAM-K and a near-cathode OPMN-P membranes, when separating model and technological solutions, a decrease in the total omics resistance of the system is observed, which is associated with the solution throttling process.

STRUCTURAL CHARACTERISTICS OF MEMBRANES AND KINETIC DEPENDENCES OF ELECTRONANOFILTRATION WASTE WATER TREATMENT OF LATINATING PROCESS

The basic structural characteristics of the membrane and kinetic dependences of the electron-filtration separation of wastewater of the brassing process are investigated. The retention factor and the specific output flow for the near-anode and near-cathode membrane were calculated. The dependences of the retention factor and the specific output flow on the transmembrane pressure and current density are analyzed, and it is noted that the anode membrane as a result of the application of a constant electric potential to the membrane-solution system starts to clog and a sludge layer forms on its surface due to the electrochemical process. A comparison is made of the retention capacity of OPMN-P and OPMN-K membranes for a real spent technological solution after the process of brazing and a model solution containing the same concentrations of copper ions (Cu2+) and zinc (Zn2+) as in real runoff. The structural characteristics of nanofiltration membranes of the type OFAM-K and OPMN-P were studied and analyzed. Changes in the crystalline and amorphous phases of the active layer and the membrane substrate are considered. The change in crystalline parameters in crystallites can be explained only by the structural features of macromolecules of polyamide and their orientation during crystallization. Under the action of transmembrane pressure and transport of water molecules, the polymorphism of the packing of the crystal lattice occurs. The packing density of the amorphous phases of the working membrane decreases, which affects the transport and selective properties of the membrane. In fact, the deformation of an amorphous-crystalline polymer leads to a restructuring of the structure not only in the orientation of the macromolecules of the amorphous, but also the crystalline phases of the membranes. It was also noted that the packing density of the amorphous phases of the working membrane decreases, which affects the transport and selective properties of the membrane.

Ultrafiltration concentration of whey in a pilot plant

Experimental data on the retention coefficient and the output specific flow are obtained. The test solutions were goat and cow's milk whey after obtaining cheese. The description, general view and technological scheme of a pilot installation of a tubular type are given. The studies were carried out on semipermeable tubular type ultrafiltration membranes manufactured by AO "ZAVKOM". Based on the studies, graphical dependences of the retention coefficient on the specific output stream were constructed and analyzed. During the analysis, it was noted that with an increase in the output specific flow of the solvent, the retention coefficient decreases. The reason for this is the boundary layers of fat and protein formed in the near-membrane layers, which prevents the passage of protein molecules through the pores of the membrane. Also during the experiment, it was noted that goat milk serum has a more oily structure and requires prior separation. For the theoretical calculation of the retention coefficient and specific output stream, mathematical expressions are developed and numerical values of the values of empirical coefficients are obtained. The developed mathematical expressions describe the experimental data with good confidence. The obtained experimental and calculated data can be used with great reliability in the calculations of mass-transported flows of substances through semipermeable membranes, as well as in engineering methods for calculating and predicting the effectiveness of the use of membrane processes for the concentration of whey.