Artículos científicos

THE OBJECTIVE OF THIS STUDY WAS TO FIND AN EFFICIENT METHOD THAT ALLOWS TIME AND YIELD INCREASE VOLUME USE AND UTILITY OF THE SAWMILLS THAT PROCESS LOGS PRUNED PINUS RADIATA, LINKING EXTERNAL INFORMATION PROVIDED BY A SCANNER INDUSTRY AND SIMULATION OF CYLINDRICAL DEFECTIVE CORE (CDC) IN THE CONSTITUTION OF A THREE-DIMENSIONAL LOG, WHERE THE OPTIMAL CUTTING PATTERN WAS ESTABLISHED BY MEANS OF A DYNAMIC PROGRAMMING ALGORITHM. SAWING WAS SIMULATED ON A SAMPLE OF 30 LOGS OBTAINED RANDOMLY INDUSTRIAL PROCESS OF SCANNING. THE RESULTS WERE COMPARED WITH THOSE OBTAINED BY A HEURISTIC DEVELOPED BY A COMPANY. DYNAMIC PROGRAMMING ALGORITHM ACHIEVED A YIELD OF THE RAW MATERIAL OF 64% AND AN AVERAGE RELATIVE NET UTILITY OF 11 US$/LOG WAS OBTAINED.

IN THIS WORK WE EXAMINE TRAPEZOIDAL CENTRAL CONFIGURATIONS IN THE PLANAR FOUR-VORTEX PROBLEM. MORE SPECIFICALLY, WE CONSIDER THE CONVEX CENTRAL CONFIGURATIONS IN WHICH THE CONVEX QUADRILATERAL HAS TWO PARALLEL SIDES. WITH ANALYTICAL ARGUMENTS WE CLASSIFY ALL POSSIBLE ARRANGEMENTS. ADDITIONALLY, WE PROVE THE UNIQUENESS OF THE TRAPEZOIDAL CENTRAL CONFIGURATION FOR GIVING FOUR VORTICITIES WITH THE SAME SIGN.

TO EVALUATE THE IMMUNE RESPONSE TO THE SARS-COV-2 VACCINES IN ADULTS WITH IMMUNE-MEDIATED RHEUMATIC DISEASES (IMRDS) IN COMPARISON TO HEALTHY INDIVIDUALS, OBSERVED 1-20 WEEKS FOLLOWING THE FOURTH VACCINE DOSE. ADDITIONALLY, TO EVALUATE THE IMPACT OF IMMUNOSUPPRESSIVE THERAPIES, VACCINATION SCHEDULES, THE TIME INTERVAL BETWEEN VACCINATION AND SAMPLE COLLECTION ON THE VACCINE?S IMMUNE RESPONSE. PERFORMING A COMPARISON BETWEEN THE VARIANTS, WUHAN VS OMICRON, WE NOTICED THAT THERE WERE SIGNIFICANT DIFFERENCES (P

MANY REPORTERS HAVE HIGHLIGHTED THAT LOCATION-BASED SERVICES (LBS) HAVE OPENED SEVERAL QUESTIONS CONCERNING PRIVACY. WHEN A CLIENT RELEASES HER LOCATION TO A LBS, SHE COULD PUT HERSELF IN DANGER. TO MITIGATE THIS ISSUE, RESEARCHERS HAVE PROPOSED SEVERAL LOCATION CLOAKING TECHNIQUES. HOWEVER, THESE SOLUTIONS HAVE SEVERAL DRAWBACKS. MOST OF THEM ARE BASED ON AN ANONYMIZER AND THEY DO NOT ADDRESS THE SCALABILITY ISSUES FACED BY THE SERVER WHEN A HIGH DEMAND FOR LOCATION PRIVACY PROTECTION IS REQUESTED. ALSO, THEY DO NOT CONSIDER THE POTENTIAL NEGATIVE IMPACT ON THE LBS WHEN POSTERIORI PROCESSING OF MANY LOCATIONCLOAKED QUERIES (LCQ). THIS PAPER CONSIDERS THE PROBLEMS OF EFFICIENT CONSTRUCTION OF LOCATION CLOAKING AREAS WHEN A TRUSTED ANONYMIZER NEEDS TO PROVIDE LOCATION PRIVACY PROTECTION FOR HETEROGENEOUS LBS CLIENTS AND TO LIMIT THE COST OF PROCESSING MANY LCQS AT THE LBS. OUR KEY GOAL IS TO BUILD SHARED CLOAKING REGIONS FOR LBS USERS LOCATED NEARBY EACH OTHER AND HAVING SIMILAR PRIVACY CONCERNS. WE PROPOSE SEVERAL BATCHING APPROACHES FOR BUILDING PROPER CLOAKING REGIONS. THROUGHOUT EXTENSIVE SIMULATIONS, WE WILL SHOW OUR APPROACH CAN BALANCE BOTH THE ANONYMIZER WORKLOAD AND LBS WORKLOAD.

TURING MACHINES HAVE BEEN STUDIED AS DYNAMICAL SYSTEMS FOR MORE THAN TWO DECADES, FIRST FORMALIZED BY KURKA, PROPOSING A TOPOLOGICAL DYNAMICAL SYSTEM NAMED TURING MACHINE WITH MOVING TAPE (TMT). IT WAS CONJECTURED THAT EVERY TMT HAS AT LEAST ONE PERIODIC POINT. NOWADAYS, THERE ARE SEVERAL EXAMPLES OF APERIODIC TURING MACHINES, DISPROVING KURKA?S CONJECTURE. MOREOVER, ONE OF THESE MACHINES, NAMED SMART, HAS OTHER INTERESTING PROPERTIES LIKE REVERSIBILITY, COMPLETENESS, APERIODICITY, TOPOLOGICAL MINIMALITY, AMONG OTHERS. THIS MACHINE HAS FOUR STATES AND WORKS OVER AN ALPHABET OF THREE SYMBOLS. IN THIS RESEARCH, WE STUDY THE DYNAMICAL PROPERTIES OF BINSMART, A 2-SYMBOLS RECONSTRUCTION OF THE MAIN DYNAMIC OF SMART MACHINE. THIS MACHINE RESULTS TO BE APERIODIC, TOPOLOGICALLY MINIMAL (THEREFORE TRANSITIVE) BUT NOT TIME-SYMMETRIC, AS IT IS NOT A DIRECT TRANSLATION OF THE ORIGINAL MACHINE. WE ALSO PROVE THAT ITS T-SHIFT IS A PRIMITIVE SUBSTITUTION.

THE HIERARCHICAL NETWORK DESIGN PROBLEM CONSISTS OF LOCATING A MINIMUM COST BI-LEVEL NETWORK ON A GRAPH. THE HIGHER LEVEL SUB-NETWORK IS A PATH VISITING TWO OR MORE NODES. THE LOWER LEVEL SUB-NETWORK IS A FOREST CONNECTING THE REMAINING NODES TO THE PATH. WE OPTIMALLY SOLVE THE PROBLEM USING AN AD HOC BRANCH AND CUT PROCEDURE. RELAXED VERSIONS OF A BASE MODEL ARE SOLVED USING AN OPTIMIZATION PACKAGE AND, IF BINARY VARIABLES HAVE FRACTIONAL VALUES OR IF SOME OF THE RELAXED CONSTRAINTS ARE VIOLATED IN THE SOLUTION, CUTTING PLANES ARE ADDED. ONCE NO MORE CUTS CAN BE ADDED, BRANCH AND BOUND IS USED. THE METHOD FOR FINDING VALID CUTTING PLANES IS PRESENTED. FINALLY, WE USE DIFFERENT AVAILABLE TEST INSTANCES TO COMPARE THE PROCEDURE WITH THE BEST KNOWN PUBLISHED OPTIMAL PROCEDURE, WITH GOOD RESULTS. IN NONE OF THE INSTANCES WE NEEDED TO APPLY BRANCH AND BOUND, BUT ONLY THE CUTTING PLANES.

IN THIS WORK, WE STUDY THE C0-NONCONFORMING VEM FOR THE FOURTH-ORDER EIGENVALUE PROBLEMS MODELING THE VIBRATION AND BUCKLING PROBLEMS OF THIN PLATES WITH CLAMPED BOUNDARY CONDITIONS ON GENERAL SHAPED POLYGONAL DOMAIN, POSSIBLY EVEN NONCONVEX DOMAIN. BY EMPLOYING THE ENRICHING OPERATOR, WE HAVE DERIVED THE CONVERGENCE ANALYSIS IN DISCRETE H2 SEMINORM, AND H1, L2 NORMS FOR BOTH PROBLEMS. WE USE THE BABUSKA-OSBORN SPECTRAL THEORY (BABUSKA AND OSBORN, 1991), TO SHOW THAT THE INTRODUCED SCHEMES PROVIDE WELL APPROXIMATION OF THE SPECTRUM AND PROVE OPTIMAL ORDER OF RATE OF CONVERGENCE FOR EIGENFUNCTIONS AND DOUBLE ORDER OF RATE OF CONVERGENCE FOR EIGENVALUES. FINALLY, NUMERICAL RESULTS ARE PRESENTED TO SHOW THE GOOD PERFORMANCE OF THE METHOD ON DIFFERENT POLYGONAL MESHES.(C) 2022 ELSEVIER B.V. ALL RIGHTS RESERVED.

IN THIS PRESENT PAPER, WE PROPOSE AND ANALYZE A -CONFORMING VIRTUAL ELEMENT METHOD TO SOLVE THE SO-CALLED ONE-LAYER STATIONARY QUASI-GEOSTROPHIC EQUATIONS (QGE) WITH APPLICATIONS IN THE LARGE SCALE WIND-DRIVEN OCEAN CIRCULATION, FORMULATED IN TERMS OF THE STREAM-FUNCTION. THIS PROBLEM CORRESPONDS TO A NONLINEAR FOURTH ORDER PARTIAL DIFFERENTIAL EQUATION. THE VIRTUAL SPACE AND THE DISCRETE SCHEME ARE BUILT IN A STRAIGHTFORWARD WAY DUE TO THE FLEXIBILITY OF THE VIRTUAL APPROACH. UNDER THE ASSUMPTION OF SMALL DATA, WE PROVE WELL-POSEDNESS OF THE DISCRETE PROBLEM BY USING A FIXED-POINT STRATEGY AND UNDER STANDARD ASSUMPTIONS ON THE COMPUTATIONAL DOMAIN, WE ESTABLISH ERROR ESTIMATES IN -NORM FOR THE STREAM-FUNCTION. FINALLY, WE REPORT FOUR NUMERICAL EXPERIMENTS THAT ILLUSTRATE THE BEHAVIOR OF THE PROPOSED SCHEME AND CONFIRM OUR THEORETICAL RESULTS ON DIFFERENT FAMILIES OF POLYGONAL MESHES.

IN THIS STUDY, WE PRESENT AND ANALYZE A VIRTUAL ELEMENT DISCRETIZATION FOR A NONSELFADJOINT FOURTH-ORDER EIGENVALUE PROBLEM DERIVED FROM THE TRANSMISSION EIGENVALUE PROBLEM. USING SUITABLE PROJECTION OPERATORS, THE SESQUILINEAR FORMS ARE DISCRETIZED BY ONLY USING THE PROPOSED DEGREES OF FREEDOM ASSOCIATED WITH THE VIRTUAL SPACES. UNDER STANDARD ASSUMPTIONS ON THE POLYGONAL MESHES, WE SHOW THAT THE RESULTING SCHEME PROVIDES A CORRECT APPROXIMATION OF THE SPECTRUM AND PROVE AN OPTIMAL-ORDER ERROR ESTIMATE FOR THE EIGENFUNCTIONS AND A DOUBLE ORDER FOR THE EIGENVALUES. FINALLY, WE PRESENT SOME NUMERICAL EXPERIMENTS ILLUSTRATING THE BEHAVIOR OF THE VIRTUAL SCHEME ON DIFFERENT FAMILIES OF MESHES.

IN THIS PAPER, WE PROPOSE AND ANALYZE A C1-VIRTUAL ELEMENT METHOD OF HIGH ORDER TO SOLVE THE BRINKMAN PROBLEM FORMULATED IN TERMS OF THE STREAM FUNCTION. THE VELOCITY IS OBTAINED AS A SIMPLE POST-PROCESS FROM STREAM FUNCTION AND A NOVEL STRATEGY IS WRITTEN TO RECOVER THE FLUID PRESSURE. WE ESTABLISH OPTIMAL A PRIORI ERROR ESTIMATES FOR THE STREAM FUNCTION, VELOCITY AND PRESSURE WITH CONSTANTS INDEPENDENT OF THE VISCOSITY. FINALLY, WE REPORT SOME NUMERICAL TEST ILLUSTRATING THE BEHAVIOR OF THE VIRTUAL SCHEME AND SUPPORTING OUR THEORETICAL RESULTS ON DIFFERENT FAMILIES OF POLYGONAL MESHES.

IN THIS PAPER, WE PROPOSE A NEW CLASS OF NON-GAUSSIAN RANDOM FIELDS NAMED TWO-PIECE RANDOM FIELDS. THE PROPOSED CLASS ALLOWS TO GENERATE RANDOM FIELDS THAT HAVE FLEXIBLE MARGINAL DISTRIBUTIONS, POSSIBLY SKEWED AND/OR HEAVY-TAILED AND, AS A CONSEQUENCE, HAS A WIDE RANGE OF APPLICATIONS. WE STUDY THE SECOND-ORDER PROPERTIES OF THIS CLASS AND PROVIDE ANALYTICAL EXPRESSIONS FOR THE BIVARIATE DISTRIBUTION AND THE ASSOCIATED CORRELATION FUNCTIONS. WE EXEMPLIFY OUR GENERAL CONSTRUCTION BY STUDYING TWO EXAMPLES: TWO-PIECE GAUSSIAN AND TWO-PIECE TUKEY-H RANDOM FIELDS. AN INTERESTING FEATURE OF THE PROPOSED CLASS IS THAT IT OFFERS A SPECIFIC TYPE OF DEPENDENCE THAT CAN BE USEFUL WHEN MODELING DATA DISPLAYING SPATIAL OUTLIERS, A PROPERTY THAT HAS BEEN SOMEWHAT IGNORED FROM MODELING VIEWPOINT IN THE LITERATURE FOR SPATIAL POINT REFERENCED DATA. SINCE THE LIKELIHOOD FUNCTION INVOLVES ANALYTICALLY INTRACTABLE INTEGRALS, WE ADOPT THE WEIGHTED PAIRWISE LIKELIHOOD AS A METHOD OF ESTIMATION. THE EFFECTIVENESS OF OUR METHODOLOGY IS ILLUSTRATED WITH SIMULATION EXPERIMENTS AS WELL AS WITH THE ANALYSIS OF A GEOREFERENCED DATASET OF MEAN TEMPERATURES IN MIDDLE EAST.

MULTILEVEL INVERTERS ARE THE ALTERNATIVE FOR MEDIUM VOLTAGE APPLICATIONS. WITHIN THIS TYPE OF INVERTERS ARE THE ASYMMETRIC INVERTERS, WHICH HAVE DIFFERENT VALUES IN THEIR DC VOLTAGES. THE DC VOLTAGE RATIOS CAN BE OF THE TRINARY OR BINARY TYPE, THE FIRST BEING THE MOST DOCUMENTED, WITH WHICH AN AC VOLTAGE OF 3 N = 27 LEVELS IS OBTAINED, USING N = 3 INVERTERS IN CASCADE AND NLM MODULATION, WHICH GENERATES A FLOW OF POWER FROM THE LOAD TO THE INVERTERS (REGENERATION). IN THIS PAPER WE ANALYZE TWO TYPES OF NON-REGENERATIVE SINGLEPHASE ASYMMETRIC INVERTERS, OF 15 AND 27 LEVELS, WHERE THEIR QUALITY OF OUTPUT VOLTAGE WAVEFORM (THD) AND EFFICIENCY ARE ANALYZED. THE LATTER WILL BE FOCUSED ON THE COMMUTATION AND CONDUCTION LOSSES IN THE SEMICONDUCTORS. IN SUCH A WAY TO BE ABLE TO MAKE A CHOICE OF THE INVERTER CONSIDERING THESE TWO INDICES. FINALLY TO CHECK WHAT IS PROPOSED, SIMULATION RESULTS ARE SHOWN.

THE INCREASING USE OF STAINLESS STEEL IN CONSTRUCTION HAS LED TO THE NEED OF DEVELOPINGRESISTANCE MODELS FOR STRUCTURAL ELEMENTS MADE OF THIS MATERIAL. UNLIKE CARBON STEELS, STAINLESS STEEL ALLOYS EXHIBIT STRESS-STRAIN CURVES WITH A PRONOUNCED STRAIN HARDENING CAPACITY AND REASONABLE DUCTILITY THAT SHOULD BE CONSIDERED IN THE DESIGN. THIS DIFFERENCE IN BEHAVIOR MAKES THE FORMULATIONS USED FOR CARBON STEEL CONSERVATIVE WHEN DESIGNING WITH STAINLESS STEEL. THEREFORE, THIS PAPER PRESENTS A COMPARATIVE ANALYSIS OFRESISTANCE MODELS FOR SLENDER AUSTENITIC STAINLESS-STEELBEAMS SUBJECT TO CONCENTRATED LOADS. FIRST, THE FAILURE MECHANISMS OF STAINLESS-STEELBEAMS ARE PRESENTED USING A NONLINEAR FINITE ELEMENT MODEL. FROM THIS VALIDATED NUMERICAL MODEL, A DATABASE OBTAINED FROM A PARAMETRIC ANALYSIS THAT COVERS A WIDE RANGE OF GEOMETRIES IS PRESENTED. SUBSEQUENTLY, THIS DATABASE IS USED TO PERFORM A COMPARISON BETWEEN VARIOUS RESISTANCE MODELS AVAILABLE IN THE LITERATURE. THESE MODELS CORRESPOND TO BOTH INTERNATIONAL DESIGN CODES AND MODELS OBTAINED THROUGH MACHINE LEARNING. FINALLY, THE NUMERICAL RESULTS SHOW CONSIDERABLE IMPROVEMENT IN THE PREDICTED ULTIMATE RESISTANCES FOR SLENDER STAINLESS STEEL PLATE GIRDERS SUBJECTED TO PATCH LOADING.

IN PREVIOUS WORK, IT WAS PROPOSED TO USE MULTILEVEL CURRENT SOURCE CONVERTERS TO INCREASE THE CURRENT CAPACITY AS WELL AS IMPROVE THE HARMONIC PROFILE OF MEDIUM VOLTAGE AND HIGH CURRENT DRIVES. RECENT PUBLICATIONS SUGGEST THAT BOTH (A) ITS INTRINSIC BOOSTER CHARACTERISTICS AND (B) ITS EASY WAY TO HANDLE INDEPENDENT DC SOURCES OPERATING IN PARALLEL MAKE THIS TOPOLOGY AN ATTRACTIVE ALTERNATIVE FOR THE DIRECT CONNECTION OF PHOTOVOLTAIC PLANTS TO THE GRID. FURTHERMORE, STAGGERED OPTIMIZED PATTERNS WERE PROPOSED TOGETHER TO MODULAR TOPOLOGIES REGARDING THE IMPROVEMENT ON HARMONIC PROFILE OF INJECTED CURRENTS TO THE GRIDS. ONE OF THESE TECHNIQUES ARE THE STAGGERED SELECTIVE HARMONIC ELIMINATION. AN ALTERNATIVE IS THE STRAIGHTFORWARD OPTIMIZATION FOR REDUCE THE ERROR AMONG A TIME-BASED REFERENCE AND THE MODULATED CURRENT PATTERN. THIS WORK PRESENTS A COMPARISON BETWEEN THREE OPTIMIZED PATTERNS FOR THE OPERATION OF STAGGERED PATTERNS IN CURRENT SOURCE CONVERTERS, FOR BOTH SYMMETRIC AND ASYMMETRIC CASES. THEORETICAL RESULTS THAT ARE VALIDATED BY SIMULATION ARE PRESENTED.

NANOINDENTATION IS A POWERFUL TOOL FOR HARDNESS TESTING ON A VERY SMALL SCALE. SINCE THE TECHNIQUE WAS FIRST INTRODUCED FOR STUDYING WOOD CELL WALL MECHANICS, IT HAS BEEN INTEGRATED AS AN IMPORTANT TOOL FOR MEASURING THE MODULUS OF ELASTICITY AND HARDNESS OF WOOD CELL WALLS. IN THIS STUDY, HARDNESS MEASURED WITH NANOINDENTATION (NANOHARDNESS) WAS COMPARED WITH HARDNESS MEASURED BY THE STANDARD BRINELL TEST METHOD (BRINELL HARDNESS) ON JACK PINE (PINUS BANKSIANA LAMB.) WOOD. NANOINDENTATION WAS PERFORMED ON BOTH THE S2 LAYER OF THE SECONDARY CELL WALL AND THE MIDDLE LAMELLA (ML) OF EARLY- AND LATEWOOD FIBERS. FOUR ANNUAL GROWTH RINGS WERE STUDIED. THE INFLUENCE OF GROWTH RING AND INITIAL SPACING ON BOTH MEASUREMENTS WAS ANALYZED. THE RELATIONSHIP BETWEEN BRINELL HARDNESS, NANOINDENTATION MEASUREMENTS, AND AVERAGE RING DENSITY WAS ALSO STUDIED. RESULTS SUGGEST THAT BRINELL- AND NANOHARDNESS ARE CONTROLLED BY DIFFERENT MECHANISMS AND FACTORS. THE LOCATION OF NANOHARDNESS MEASUREMENTS (I.E., S2 LAYER OR ML) ALSO INFLUENCED HARDNESS DIFFERENTLY. IT WAS CONCLUDED THAT NANOMEASUREMENTS ARE NOT AN EXACT REPRESENTATION OF WOOD MECHANICAL PROPERTIES CONDUCTED AT THE MACRO LEVEL BECAUSE OF THE HIERARCHICAL STRUCTURE OF WOOD. THE EFFECT OF OTHER FACTORS SUCH AS MOISTURE OR WOOD EXTRACTIVE CONTENT MAY ALSO NEED CONSIDERATION.

THE PERFORMANCE OF SAWMILLS IS STRONGLY DEPENDENT ON HOW LOGS ARE SAWN INTO LUMBER IN ORDER TO SATISFY THE CUSTOMER DEMANDS. TO DO THIS, SAWMILL MANAGERS HAVE TO DECIDE WHICH CUTTING PATTERNS HAVE TO BE APPLIED TO LOGS OF DIFFERENT DIMENSIONS. OPTIMIZATION MODELS HAVE BEEN PROPOSED TO ASSIST DECISION MAKERS IN THIS PROCESS, BUT ONLY THE PROFIT MAXIMIZATION AND THE COST MINIMIZATION OF THE DECISIONS HAVE BEEN CONSIDERED AS THE MODELS OBJECTIVE. IN THIS PAPER, A LINEAR OPTIMIZATION MODEL WAS FORMULATED TO ADDRESS LUMBER PRODUCTION PLANNING AND APPLIED TO A REAL PROBLEM. THE CURRENT DECISIONS AT SAWMILLS WERE COMPARED WITH FIVE DIFFERENT OBJECTIVE FUNCTIONS: THE TWO PREVIOUSLY MENTIONED PLUS WASTE MINIMIZATION, LOG NUMBER MINIMIZATION AND PRODUCTION TIME MINIMIZATION. ONLY PROFIT MAXIMIZATION AND WASTE MINIMIZATION MODELS REPORTED POSITIVE ECONOMIC RETURNS. ALTHOUGH THE CURRENT DECISION AT SAWMILLS ALSO REPORTED A POSITIVE ECONOMIC RETURN, THE SAME ECONOMIC RESULT WAS OBTAINED WITH SIGNIFICANTLY FEWER RESOURCES USING THE WASTE MINIMIZATION MODEL. THE EFFECTS OF THE DIFFERENT OBJECTIVES ON THE PRODUCTION INDICATORS WERE DISCUSSED.

WE FIRST ESTABLISH SUFFICIENT CONDITIONS ENSURING STRONG DUALITY FOR CONE CONSTRAINED NONCONVEX OPTIMIZATION PROBLEMS UNDER A GENERALIZED SLATER-TYPE CONDITION. SUCH CONDITIONS ALLOW US TO COVER SITUATIONS WHERE RECENT RESULTS CANNOT BE APPLIED. AFTERWARDS, WE PROVIDE A NEW COMPLETE CHARACTERIZATION OF STRONG DUALITY FOR A PROBLEM WITH A SINGLE CONSTRAINT: SHOWING, IN PARTICULAR, THAT STRONG DUALITY STILL HOLDS WITHOUT THE STANDARD SLATER CONDITION. THIS YIELDS LAGRANGE MULTIPLIERS CHARACTERIZATIONS OF GLOBAL OPTIMALITY IN CASE OF (NOT NECESSARILY CONVEX) QUADRATIC HOMOGENEOUS FUNCTIONS AFTER APPLYING A GENERALIZED JOINT-RANGE CONVEXITY RESULT. FURTHERMORE, A RESULT WHICH REDUCES A CONSTRAINED MINIMIZATION PROBLEM INTO ONE WITH A SINGLE CONSTRAINT UNDER GENERALIZED CONVEXITY ASSUMPTIONS, IS ALSO PRESENTED.

THE EFFECTS OF PARTIAL SHADING OR DUST ACCUMULATION ON THE PANELS OF PHOTOVOLTAIC SYSTEMS CONNECTED TO THE GRID CAN GENERATE A CONSIDERABLE REDUCTION IN ENERGY PERFORMANCE, BEING NECESSARY TO PROVIDE THE APPROPRIATE VOLTAGE TO THE GRID REGARDLESS OF THE IRRADIANCE LEVEL. THIS PAPER ADDRESSES THIS PROBLEM AND PRESENTS A COMPREHENSIVE CONTROL STRATEGY AND ITS IMPLEMENTATION FOR A GRID-CONNECTED MICROINVERTER COMPOSED OF A PUSH?PULL CONVERTER FOLLOWED BY AN H-BRIDGE INVERTER. IN THE PUSH?PULL CONVERTER, A HYBRID MPPT ALGORITHM AND A PI CONTROL ENABLE WORK IN THE MPP OF THE PV PANEL. IN THE H-BRIDGE INVERTER, A CASCADE CONTROL CONSISTING OF A PI CONTROL AND A PREDICTIVE CONTROL ALLOWS THE CONNECTION TO THE GRID. A PROOF-OF-CONCEPT PROTOTYPE IS IMPLEMENTED IN ORDER TO VALIDATE THE PROPOSAL. EXPERIMENTAL TESTS WERE PERFORMED BY CONNECTING THE MICROINVERTER TO A PV PANEL AND A PROGRAMMABLE PHOTOVOLTAIC PANEL EMULATOR TO CHECK THE MPPT PERFORMANCE. FURTHERMORE, PARTIAL SHADING CONDITIONS WERE SIMULATED ON THE DC SOURCE TO CHECK IF THE GLOBAL MAXIMUM POWER POINT IS REACHED. EXPERIMENTAL RESULTS DEMONSTRATE THE FEASIBILITY OF THE TOPOLOGY AND THE CONTROL APPROACH, OBTAINING MPPT PERFORMANCE IN THE TOPOLOGY ABOVE 99% AT DIFFERENT POWER AND VOLTAGE LEVELS ON THE MPPT, EVEN IN THE PRESENCE OF PARTIAL SHADING CONDITIONS.

THE CONSTRUCTION INDUSTRY IS CURRENTLY TECHNOLOGICALLY CHALLENGED TO INCORPORATE NEW DEVELOPMENTS FOR ENHANCING THE PROCESS, SUCH AS THE USE OF 3D PRINTING FOR COMPLEX BUILDING STRUCTURES, WHICH IS THE AIM OF THIS BRIEF. TO DO SO, WE SHOW A SYSTEMATIC STUDY REGARDING THE USABILITY AND PERFORMANCE OF MOBILE MANIPULATORS AS DISPLACEABLE 3D PRINTING MACHINERY IN CONSTRUCTION SITES, WITH EMPHASIS ON THE THREE MAIN DIFFERENT EXISTING MOBILE PLATFORMS: THE CAR-LIKE, THE UNICYCLE AND THE OMNIDIRECTIONAL (MECANUM WHEELED), WITH AN UR5 MANIPULATOR ON THEM. TO EVALUATE ITS PERFORMANCE, WE PROPOSE THE PRINTING OF THE FOLLOWING BUILDING ELEMENTS: HELICAL, SQUARE, CIRCULAR AND MESH, WITH DIFFERENT SIZES. AS METRICS, WE CONSIDER THE TOTAL CONTROL EFFORT OBSERVED IN THE ROBOTS AND THE TOTAL TRACKING ERROR ASSOCIATED WITH THE ENERGY CONSUMED IN THE ACTIVITY TO GET A MORE SUSTAINABLE PROCESS. IN ADDITION, TO FURTHER TEST OUR WORK, WE CONSTRAINED THE ROBOT WORKSPACE THUS RESEMBLING REAL LIFE CONSTRUCTION SITES. IN GENERAL, THE STATISTICAL RESULTS SHOW THAT THE OMNIDIRECTIONAL PLATFORM PRESENTS THE BEST RESULTS ?LOWEST TRACKING ERROR AND LOWEST CONTROL EFFORT? FOR CIRCULAR, HELICOIDAL AND MESH BUILDING ELEMENTS; AND CAR-LIKE PLATFORM SHOWS THE BEST RESULTS FOR SQUARE-LIKE BUILDING ELEMENT. THEN, AN INNOVATIVE PERFORMANCE ANALYSIS IS ACHIEVED FOR THE PRINTING OF BUILDING ELEMENTS, WITH A CONTRIBUTION TO THE REDUCTION OF ENERGY CONSUMPTION.