IN HARD ROCK MINE OPERATIONS, THE GRAVITATIONAL SEGREGATION OF ORE PARTICLES WITHIN A STOCKPILE CREATES A HIGH VARIATION OF PARTICLE SIZE. THIS ISSUE HAMPERS PRODUCTIVITY IN THE COMMINUTION PROCESS AND HAS A DIRECT EFFECT ON THE DAILY OUTPUT OF PRODUCED MINERALS FROM THE MINE. DOZER OPERATION CAN BE FACILITATED TO MIX THE STOCKPILE MATERIALS FOR MAINTAINING A MORE HOMOGENEOUS PARTICLE SIZE DISTRIBUTION, HOWEVER THIS CAN LEAD TO POTENTIALLY HAZARDOUS SITUATIONS FOR THE MACHINE AND OPERATOR DUE TO THE DYNAMIC NATURE OF THE STOCKPILE. THE USE OF AUTONOMOUS BULLDOZERS IS A NEW TREND FOR MINE EQUIPMENT OPERATION, IMPROVING THE SAFETY OF DOZER OPERATORS WORKING IN THE STOCKPILE BY REMOVING THEM FROM THE MACHINE ALTOGETHER. THIS PAPER DESCRIBES PATH-PLANNING STRATEGY FOR AUTONOMOUS DOZERS TO OPERATE OVER A STOCKPILE WITHIN A PREDEFINED SAFE REGION. FOR THIS PURPOSE, A STOCKPILE MODEL IS DEVELOPED, WHERE LEVEL AND PARTICLE SIZE PROPERTIES ARE USED TO DESCRIBE THE STOCKPILE IN TERMS OF SECTORS. THIS INFORMATION IS THEN USED TO COMMAND THE OPERATION OF AN AUTONOMOUS DOZER OVER THE STOCKPILE BASED ON CURRENT SAG MILL FEED STATE. SIMULATION RESULTS PREDICT ACCEPTABLE BEHAVIOR, PROVIDED THAT SENSOR INFORMATION PROVIDES ENOUGH ACCURACY TO SPECIFY SAFETY AND PERFORMANCE CONSTRAINS.

THIS PAPER PRESENTS AN APPROACH TO TAKE ADVANTAGE OF REVIEWS WRITTEN IN SPANISH TO GENERATE ASPECT-BASED RECOMMENDATIONS. ALTHOUGH DIVERSE APPROACHES HAVE BEEN PROPOSED AND EVALUATED FOR REVIEWS WRITTEN IN ENGLISH, THERE IS A LACK OF PROPOSALS TO ACCOMPLISH THIS TASK USING REVIEWS IN SPANISH. THE PROPOSED APPROACH USES TEXT MINING TECHNIQUES AND TOOLS TO EXTRACT ITEM ASPECTS AND ESTIMATE USER PREFERENCES FOR EACH OF THEM. THE ESTIMATED PREFERENCES THEN FEED A MULTI-CRITERIA RECOMMENDER SYSTEM, CONSIDERING EACH EXTRACTED ASPECT AS A CRITERION REGARDING USER PREFERENCE. PRELIMINARY RESULTS SHOW THAT, USING ASPECTS EXTRACTED FROM REVIEWS WRITTEN IN SPANISH, IT IS POSSIBLE TO IMPROVE THE QUALITY OF RECOMMENDATIONS GENERATED WITH A TRADITIONAL ALGORITHM. DUE TO THE SIMPLICITY OF THE PROPOSED APPROACH, IT CAN BE EASILY USED BY LOCAL COMPANIES TO INCORPORATE ASPECT-BASED RECOMMENDATIONS.

CLIMATE CHANGE ALONG WITH THE LACK OF AVAILABILITY OF ELECTRICITY IN AGRICULTURAL LANDS HAVE LED TO INCREASED PRODUCTION COSTS FOR FARMERS. THESE FACTORS ARE LEADING FARMERS TO INCORPORATE THE USE OF NEW TECHNOLOGIES IN SEARCH OF MORE SUSTAINABLE SOLUTIONS FOR PRODUCTION. IN THIS CONTEXT, THE USE OF RENEWABLE ENERGY, IN PARTICULAR, PHOTOVOLTAIC SYSTEMS TO PROVIDE OFF-GRID SOLUTIONS FOR AGRICULTURE APPLICATIONS HAS GAINED RELEVANCE. CURRENTLY, SEVERAL PROGRAMS IMPULSED BY THE CHILEAN GOVERNMENT ARE IN PLACE TO INCENTIVE THE USE OF SOLAR ENERGY FOR FARMING APPLICATIONS; HOWEVER, SOME OF THESE INITIATIVES LACK TOOLS THAT MAY ALLOW FARMERS TO VALIDATE AND ASSESS THE EFFICACY OF THE PROPOSED SOLUTIONS. THIS WORK IS FOCUSED ON THE DEVELOPMENT OF A SIMPLE VALIDATION METHOD SUITABLE TO BE USED BY NON-EXPERTS TO ASSESS THE EFFICACY OF SOLAR ENERGY-BASED SOLUTIONS FOR FARMING APPLICATIONS. THE PROPOSED METHODOLOGY CONSIDERS TAKING ADVANTAGE CURRENTLY AVAILABLE TOOLS ALONG WITH COLLECTING AND ANALYZING SIMPLE MEASURES OVER THE INSTALLED GENERATION SYSTEM, IN ORDER TO PROVIDE A REASONABLE ASSESSMENT OF SYSTEM PERFORMANCE. THE PROPOSED METHOD IS ILLUSTRATED ON A REAL INSTALLATION USED TO SUPPLY POWER TO A WATERING SYSTEM FOR BERRIES. BASED ON THE OBTAINED RESULTS, THE DEVELOPED TOOLS SEEM SUITABLE TO BE USED BY NON-EXPERTS TO ASSESS PERFORMANCE AND TO IMPLEMENT SEASONAL PERFORMANCE IMPROVEMENTS.

IN THIS PAPER, A METHOD FOR ESTIMATING SNOW PRESSURE REFLECTION COEFFICIENT BASED ON NON-CONTACT ULTRASOUND EXAMINATION IS DESCRIBED. A CONSTANT FREQUENCY AND AIR-COUPLED ULTRASOUND PULSES WERE USED IN THIS STUDY, WHICH INCORPORATES A PARAMETRIC METHOD FOR REFLECTED ENERGY ESTIMATION. THE EXPERIMENTAL PART WAS CARRIED OUT IN SITU IN THE ANTARCTIC, WHERE THE SNOW PARAMETERS WERE MEASURED ALONG WITH METEOROLOGICAL DATA. THE PROPOSED METHOD REPRESENTS A PROMISING ALTERNATIVE FOR ESTIMATING THE SNOW-WATER EQUIVALENT, SINCE IT USES A PARAMETRIC APPROACH, WHICH DOES NOT REQUIRE MEASUREMENTS OF ABSOLUTE VALUES FOR ACOUSTIC PRESSURE.

THE PROJECTED INCREASE IN ENERGY DEMAND IN CHILE, ALONG WITH THE NEED OF MORE SUSTAINABLE ENERGY SOLUTIONS ARE INCREASING THE USE OF RENEWABLE ENERGIES IN CHILE. AMONG CURRENTLY USED RENEWABLES, SOLAR POWER REPRESENTS ONE OF THE MOST PROMISING OPTIONS, GIVEN THE HIGH IRRADIANCE LEVELS AVAILABLE IN THE ATACAMA DESERT. SOLAR POWER CAN BE IMPLEMENTED AS PHOTOVOLTAIC (PV) AND CONCENTRATING SOLAR POWER (CSP) SYSTEMS, BEING THE FIRST ALTERNATIVE THE MOST POPULAR NOWADAYS. IN ORDER FOR CSP TO BECOME A SUSTAINABLE ALTERNATIVA FOR POWER GENERATION IN CHILE, ECONOMIC AND ENVIRONMENTAL IMPACTS NEED TO BE CONSIDERED. THIS WORK PRESENTS A COMPARATIVE ANALYSIS BETWEEN THE ECONOMIC AND ENVIRONMENTAL IMPACTS OF CSP AND PV SYSTEMS IN CHILE. THE STUDY EMPLOYS THE LEVELIZED COST OF ENERGY AND LIFE-CYCLE ANALYSIS TO EVALUATE HYPOTHETICAL SYSTEMS, UNDER CONDITIONS CURRENTLY AVAILABLE IN THE NORTH OF CHILE. RESULTS OBTAINED SHOW THAT ECONOMIC COST OF PV REMAIN LOWER THAN CSP, HOWEVER CSP CAN ACHIEVE LOWER ENVIRONMENTAL IMPACTS AND SUPPLY POWER CONTINUOUSLY. THESE RESULTS SUGGEST BOTH THE NEED FOR MORE APPLIED STUDIES IN SOLAR PLANTS IN CHILE, ALONG WITH IMPROVED REGULATIONS WHICH CONSIDER LCA ANALYSIS TO TRULY ASSESS THE IMPACTS OF SOLAR POWER AND CHOOSE THE MORE EFFECTIVE AND SUSTAINABLE ENERGY SOLUTIONS. © 2019 IEEE.

CURRENTLY, SEVERAL COUNTRIES ARE SEEKING TO CHANGE THEIR ENERGY MATRICES TOWARDS MORE SUSTAINABLE SOURCES. IN CHILE, ONE OF THE RENEWABLE SOURCES WITH INCREASED PARTICIPATION IS PHOTOVOLTAICS. HOWEVER, PHOTOVOLTAIC ENERGY SOURCES HAVE AN INTRINSIC VARIABILITY, WHICH COMBINED WITH VARIABLE DEMAND IMPOSES A CHALLENGE FOR PROPER DESIGN. CURRENTLY, TOOLS AVAILABLE FOR THE STUDY OF THIS VARIABILITY ARE EITHER COMPLEX OR EXPENSIVE. WITH THE ADVENT OF DIGITALIZATION, THERE IS AN OPPORTUNITY TO INCORPORATE TOOLS BASED ON ARTIFICIAL INTELLIGENCE TO IMPROVE FORECASTING FOR MEDIUM AND LOW POWER INSTALLATIONS. THIS WORK PRESENTS AN APPLICATION OF MACHINE LEARNING TOOLS FOR IRRADIANCE AND POWER CONSUMPTION FORECASTING. THE METHODOLOGY IS INTENDED TO BE IMPLEMENTED AS A LOW COST SOLUTION FOR SMALL SCALE GENERATION. THE RESULTS SHOW THAT IT IS POSSIBLE TO PREDICT IRRADIANCE AND ENERGY CONSUMPTION THROUGH HISTORICAL DATA, CONCLUDING THAT THE METHODOLOGY BASED ON MACHINE LEARNING IS ABLE TO SUPPORT THE DECISION MAKING FOR THE IMPROVEMENT OF PHOTOVOLTAIC SYSTEMS.

ENERGY CONSUMPTION REPRESENTS A HIGH OPERATIONAL COST IN MINING OPERATIONS. ORE SIZE REDUCTION STAGE IS THE MAIN CONSUMER IN THAT PROCESS, WHERE THE SEMIAUTOGENOUS MILL (SAG) IS ONE OF THE MAIN COMPONENTS. THE IMPLEMENTATION OF CONTROL AND AUTOMATION STRATEGIES THAT CAN ACHIEVE PRODUCTION GOALS ALONG WITH ENERGY EFFICIENCY ARE A COMMON GOAL IN CONCENTRATOR PLANTS; HOWEVER, DESIGNING SUCH CONTROLS REQUIRES A PROPER UNDERSTANDING OF PROCESS DYNAMICS WHICH ARE HIGHLY COMPLEX. THIS WORK STUDIES MACHINE LEARNING AND DEEP LEARNING STRATEGIES THAT CAN BE USED TO GENERATE MODELS FOR PREDICTING ENERGY CONSUMPTION, USING KEY PROCESS VARIABLES. IN PARTICULAR, THE APPLICATION OF K-NEAREST NEIGHBORS REGRESSOR (KNN-REG), POLYNOMIAL REGRESSION (PR), SUPPORT VECTOR REGRESSION (SVR) AND LONG-SHORT TERM MEMORY (LSTM) STRATEGIES FOR ENERGY PREDICTION OVER SAG MILL PROCESS DATA IS DEVELOPED IN ORDER TO IDENTIFY CONFIGURATIONS SUITABLE TO BE IMPLEMENTED FOR REAL-TIME PREDICTION INTEGRATED OVER INDUSTRIAL DATA INFRASTRUCTURES. ALL TECHNIQUES ARE COMPARED IN TERMS OF ROOT MEAN SQUARE ERROR (RMSE) WHERE, ALTHOUGH ALL THE MODELS ACHIEVED ACCEPTABLE PERFORMANCE, BEST RESULTS WERE OBTAINED BY A LSTM IMPLEMENTATION WHICH YIELDED AN ERROR OF LESS THAN 4% ASSOCIATED TO ENERGY PREDICTION.

IN THE MINING INDUSTRY, SPECIFICALLY IN THE FLOTATION PROCESS, THERE IS A CHALLENGE ASSOCIATED TO NONINVASIVE, REAL-TIME CONTAMINANT AND IMPURITIES ESTIMATION. ACHIEVING PREDICTIONS ON CONTAMINANT LEVELS HAS A HIGH IMPACT ON QUALITY INSURANCE AND IT CAN HELP TECHNICIANS AND ENGINEERS TO MAKE ADJUSTMENTS IN ADVANCE TO IMPROVE THE QUALITY OF THE FINAL PRODUCT, AND THUS PROFITS. IN THIS PAPER, EXPLORATORY RESEARCH IS PERFORMED ON THE PROBLEM OF SILICA CONCENTRATE ESTIMATION FOR IRON ORE FROTH FLOTATION USING MACHINE LEARNING TECHNIQUES, WITH THE GOAL TO IDENTIFY ALGORITHMS THAT MAY BE SUITABLE FOR INDUSTRY SOFT SENSOR DEVELOPMENT. FOR THIS PURPOSE, A PUBLIC, REAL PROCESS DATASET IS USED AND THREE DIFFERENT MACHINE LEARNING TECHNIQUES ARE IMPLEMENTED: RANDOM FOREST (RF), LONG SHORT-TERM MEMORY (LSTM) AND GATED RECURRENT UNIT (GRU). THE TECHNIQUES WERE IMPLEMENTED, TESTED AND COMPARED IN TERMS OF THEIR ERROR PERCENTAGE, MEAN ABSOLUTE ERROR, MEAN SQUARE ERROR, AND ROOT MEAN SQUARE ERROR. OBTAINED RESULTS SHOW ACCEPTABLE PERFORMANCE FOR LTSM AND GRU IMPLEMENTATIONS, BEING LSTM NETWORK THE OUT-PERFORMER WITH ERRORS BELOW 9%.

IN THIS ABSTRACT WE DESCRIBE A FRAMEWORK FOR COMPUTATIONALLY-AWARE COMPUTING THROUGH SET-VALUED MODEL PREDICTIVE CONTROL. MODEL-PREDICTIVE CONTROL (MPC) CAN ENABLE MULTI-OBJECTIVE OPTIMIZATION IN REAL-TIME, THOUGH IT DEPENDS ON ACCURATE MODELS THROUGH WHICH FUTURE STATE VALUES CAN BE PREDICTED. THIS ABSTRACT IMPROVES UPON EXISTING MPC APPROACHES IN THAT IT CONSIDERS THE STATE TO BE A SET (RATHER THAN A SINGLETON IN THE STATE), ALLOWING THE TRAJECTORIES TO BE GIVEN BY A SEQUENCE OF SETS. THE FRAMEWORK IS BENEFICIAL FOR PHYSICAL SYSTEMS CONTROL WHERE THE UNCERTAINTY IN FUTURE PROJECTION CAN BE ATTRIBUTED TO BOTH MODEL ERROR, AND ENVIRONMENTAL OR SENSOR UNCERTAINTY, THUS PROVIDING GUARANTEES OF PERFORMANCE, ROBUSTLY. WE PROVIDE AN OVERVIEW OF THE FRAMEWORK, AND INCLUDE DISCUSSION FOR ITS ADVANTAGES.

THE IMPORTANCE OF ELECTROMOBILITY, RENEWABLE ENERGIES, VARIABLES POWER MANAGERS, HAVE MAKE POWER CONVERTERS IMPORTANT DEVICES TO BE USED. HOWEVER, THESE DEVICES REQUIRE PROPER CONTROL IN ORDER TO ACHIEVE THE DYNAMIC AND STEADY STATE PERFORMANCE DESIRED FOR CURRENTS AND VOLTAGES. THIS PAPER PROPOSES AN OPTIMAL CURRENT CONTROL WITH A LINEAR-QUADRATIC REGULATOR ON A THREE-PHASE INVERTER. THE CONTROLLER?S PERFORMANCE RELIES ON THE WEIGHTING MATRIXES, WHERE THESE MATRIXES ARE CHOSEN TO ENSURE A SATISFACTORY CURRENT TRACKING, A LIMITED OVERSHOOT AND A GIVEN DYNAMIC. THE DQ0 ROTATING REFERENCE FRAME TRANSFORMATION IS USED TO OBTAIN THE NONLINEAR SPACE-STATE MODEL, WHICH IS THEN LINEARIZED TO APPLY THE LQR CONTROL OVER CONTINUOUS VARIABLES. THE EFFECTIVENESS OF THE CONTROL?S CURRENT ERROR MINIMIZATION IS CONFIRMED THROUGH SIMULATIONS RESULTS.

RENEWABLE ENERGIES HAVE BROUGHT A SOLUTION FOR PERMANENT AND INEXHAUSTIBLE ENERGY MANAGEMENT. THE APPLICATIONS ARE NUMEROUS AND EVERY DAY MORE ACCESSIBLE FOR SMALLER COMPANIES THAT NEED TO REDUCED THEIR ENERGY EXPENSES. THIS PAPER STUDIES AND ANALYSES THE ECONOMIC IMPACT OF SOLAR ENERGY INSTALLATION ON A SMALL FARM CLOSE TO QUILLÓN, CHILE, A LITTLE TOWN WHOSE ECONOMY IS MAINLY BASED ON FRUITS AND VEGETABLES PRODUCTION. THE PROPOSED METHODOLOGY DIVIDES THE ANALYSIS INTO THREE CASES, WHICH DETERMINE THE SELECTION OF THE NUMBER OF PANELS ACCORDING TO (1) SUPPLYING OF THE TOTAL DEMAND IN THE MONTH WITH THE HIGHEST SOLAR IRRADIATION, (2) SUPPLYING OF THE TOTAL DEMAND IN THE MONTH WITH THE LOWEST SOLAR IRRADIATION, AND (3) SUPPLYING THE TOTAL DEMAND WITHOUT HAVING ENERGY EXCESSES INJECTED INTO THE GRID, BUT ONLY PRODUCE FOR SELF-SUPPLYING. ALL THE CASES ARE STUDIED AND THEREFORE THE DECISION MAY FOLLOW THE ECONOMIC ASPECT OF INVESTMENT IN THE SHORT, MIDDLE, AND LONG TERM. THUS, THESE ALTERNATIVES ARE VISIBLE FOR PRODUCERS TO TAKE THE OPTION THAT BEST FITS THEM.

OPINIONS ABOUT ITEM?S ASPECTS IN USER REVIEWS MAY BE A VALUABLE SOURCE OF INFORMATION FOR IMPROVING RECOMMENDER SYSTEMS PERFORMANCE. DESPITE IMPORTANT ADVANCES IN NATURAL LANGUAGE PROCESSING AND MACHINE LEARNING FIELDS THAT ALLOW THE EXTRACTION OF SUCH INFORMATION FROM TEXTS WRITTEN IN ENGLISH, THERE IS STILL WORK TO DO IN THE CASE OF TEXTS IN OTHER LANGUAGES. IN THIS WORK, WE ADAPT KNOWN UNSUPERVISED ASPECT EXTRACTION APPROACHES TO EXTRACT OPINIONS FROM REVIEWS WRITTEN IN SPANISH. OUR RESULTS SHOW THAT THE EXPLOITATION OF ASPECTS EXTRACTED AUTOMATICALLY FROM REVIEWS WRITTEN IN SPANISH ALLOW TO IMPROVE CONSIDERABLY THE TOP-K RECOMMENDATION LISTS GENERATED BY ASPECT-BASED RECOMMENDER SYSTEMS.

GREENHOUSE GASES EMISSIONS (GHG) REDUCTION STRATEGIES HAVE GAINED INTEREST IN THE RECENT DECADE, AS THEY CAN POSITIVELY IMPACT ENVIRONMENTAL AND LIFE QUALITY IN BIG CITIES. TRANSPORTATION IS RESPONSIBLE FOR A GREAT PERCENTAGE OF THESE EMISSIONS, WHICH ARE STRONGLY RELATED TO FUEL CONSUMPTION PROFILES ALONG WITH TRAJECTORY CHARACTERISTICS. AVAILABLE TECHNOLOGIES, SUCH AS GPS TRACKING, GENERATE DATA WHICH CAN BE USED TO BETTER CHARACTERIZE FUEL CONSUMPTION AND GHG EMISSIONS ALONG A TRAJECTORY AND THUS HELP MAKE BETTER PLANNING TOWARDS ENERGY EFFICIENT AND REDUCE EMISSIONS PATHS. THIS WORK SEEKS TO CHARACTERIZE ENERGY CONSUMPTION AND GHG EMISSIONS GENERATED BY HEAVY-DUTY VEHICLES. IMPLEMENTED METHODOLOGY ALLOWS FOR ESTIMATING INSTANTANEOUS POWER DEMAND OF A HAUL TRUCK ALONG WITH FUEL CONSUMPTION AND ASSOCIATED GHG EMISSIONS. GPS DATA PROCESSING IS IMPLEMENTED BY A SERIES OF PROCESSES SUPPORTED BY PYTHON. TRUCK TRAJECTORY INFORMATION IS STORED BY MEANS OF AN AD-HOC DATA STRUCTURE, WHICH CONSISTS OF SPACE-TIME LINEAR SEGMENTS OF EQUAL SIZE THAT CONTAIN THE SPEED AND INSTANTANEOUS ACCELERATION OF THE VEHICLE. IN THIS WAY IT IS POSSIBLE TO ESTIMATE INSTANTANEOUS POWER AT EACH POINT OF THE TRAJECTORY. THE OBTAINED RESULTS INDICATE THAT AREAS WITH HIGHER POWER CONSUMPTION COINCIDE WITH HIGHER SLOPE VARIATION IN THE TRAJECTORY, WHILE AREAS WITH LOWER CONSUMPTION COINCIDE WITH THE AREAS WHERE THE ELEVATION REMAINS CONSTANT, THIS IS REFLECTED IN FUEL CONSUMPTION RATE.

SEVERE CLIMATE CHANGE EFFECTS ALONG WITH THE INCREASING NEED FOR COUNTRIES TO BECOME INDEPENDENT FROM FOSSIL FUELS ARE LEADING COUNTRIES TO SEEK MORE SUSTAINABLE ENERGY SOURCES. THIS IS NOT AN EASY TASK, AS MANY RENEWABLES LACK THE PORTABILITY AND REDUCED VARIABILITY WHICH IS REQUIRED TO PROPERLY SATISFY ENERGY DEMANDS. IN THIS CONTEXT, HYDROGEN TECHNOLOGIES ARE A PROMISING ALTERNATIVE TO WORK TOWARDS THIS GOAL. THIS WORK PRESENTS A BRIEF SUMMARY ON HYDROGEN TECHNOLOGY PROPERTIES, FOCUSING IN PARTICULAR ON THE DESCRIPTION OF HYDROGEN CELLS, THEIR CHARACTERISTICS AND MAIN APPLICATIONS. FINALLY, THE OPERATION OF A PEM CELL IS SIMULATED USING A COMPUTER MODEL, IN ORDER TO ILLUSTRATE HOW THESE TOOLS CAN BE USED TO FURTHER CHARACTERIZE PEM CELL PERFORMANCE WHEN DESIGNING HYDROGEN-BASED SOLUTIONS.

RENEWABLE ENERGIES SOURCES HAVE GROWN REGULARLY IN THE LAST YEAR, BECAUSE THEY HAVE BEEN A SOLUTION NOT ONLY FOR REDUCING THE POWER EXPENSES BUT ALSO TO BE EMPLOYED IN THE REMOTE AREAS AND PLACES, MOREOVER, ALL COMPANIES WILL BE OBLIGATED TO PRODUCE OR BUY CLEAN ENERGY TO REACH CARBON NEUTRAL IN 2025. THUS, THIS PAPER MAKES THE TECHNICAL AND ECONOMICAL ANALYSIS OF INCLUDING SOLAR POWER SYSTEM IN A MAYOR BERRIES AGROINDUSTRY. THE STUDY INCLUDES ALL CONSIDERATIONS THE FARMERS SHOULD CONSIDER FOR SOLAR PANEL INSTALLATION IN ORDER TO NOT ONLY PRODUCE FOR THEMSELVES BUT ALSO SELL THE SURPLUS TO THE GRID. THIS IS IMPORTANT, SINCE DURING WINTER SEASON THE IRRIGATION ENERGY REQUIREMENTS IS MINIMAL COMPARE WITH THE MIDDLE OF THE SUMMER, AND THEREFORE THE TOTAL AMOUNT OF PRODUCED ENERGY SHOULD BE SOLD TO THE GRID IN ORDER TO IMPROVE THE INVESTMENT PAYBACK TIME. THE COMPLETE ANALYSIS IS ILLUSTRATED BASED ON THE ACTUAL NORMATIVE AND TOOLS TO CONFIGURE SOLAR SYSTEMS.

THIS ARTICLE PRESENTS A REVIEW OF THE PREDICTIVE CONTROL TECHNIQUES APPLIED IN A VOLTAGE SOURCE INVERTER TO REGULATE THE DIRECT VOLTAGE (ACTIVE POWER) AND THE REACTIVE POWER INJECTED INTO THE GRID. AS DEADBEAT AND FINITE STATE CONTROL ARE BASED ON THE SYSTEM MODEL, THEY LEAD TO A FASTER RESPONSE AND WITHOUT OVERSHOOT, HOWEVER, THEY ARE NORMALLY USED IN INTERNAL CURRENT CONTROL LOOPS, IN THIS CASE THEIR APPLIED BEHAVIORS ARE PRESENTED AS SUCH, BUT THE APPLICATION OF A DEADBEAT BASED ON THE GENERAL MODEL OF THE STATIC CONVERTER IS ALSO STUDIED, THUS CONTRIBUTING ITS ADVANTAGES TO THE CONTROL OF THE DC VOLTAGE. WHEN IMPLEMENTING THE LATTER, SOME CONSIDERATIONS RELATED TO THE HIGH POWER NECESSARY TO REACH THE REFERENCES -ESPECIALLY IN DIRECT VOLTAGE- IN A FEW CONTROL STEPS, IN ADDITION THE DEVICE IS PROTECTED BY LIMITING THE MAXIMUM POWER DRAINED FROM THE SOURCE. THE MATHEMATICAL DEVELOPMENT IS CARRIED OUT ACCORDING TO THE POWER OF THE CONVERTER, LIMITING IT, BUT TRACKING THE REFERENCES WITH HIGH DYNAMICS. THE SYSTEM IS SUBJECTED TO SIGNIFICANT DISTURBANCES, DEMONSTRATING THEIR ROBUSTNESS TO SUCH EVENTS.

MODEL PREDICTIVE CONTROL (MPC) IS A VALUABLE TOOL TO DEAL WITH SYSTEMS THAT REQUIRE OPTIMAL SOLUTIONS AND CONSTRAINT SATISFACTION. IN THE CASE OF SYSTEMS WITH UNCERTAINTY, THE FORMULATION OF PREDICTIVE CONTROLLERS REQUIRES MODELS WHICH ARE CAPABLE TO CAPTURE SYSTEM DYNAMICS, CONSTRAINTS AND ALSO SYSTEM UNCERTAINTY. IN THIS WORK WE PRESENT A FORMULATION FOR A SETVALUED MODEL PREDICTIVE CONTROL (SVMPC) WHERE UNCERTAINTY IS REPRESENTED IN TERMS OF SETS. THE APPROACH PRESENTED HERE CONSIDERS A MODEL WHERE THE STATE IS SET-VALUED AND DYNAMICS ARE DEFINED BY A SET-VALUED MAP. THE COST FUNCTION ASSOCIATED TO THE PROPOSED MPC ASSOCIATES A REAL-VALUED COST TO EACH SET VALUED (OR TUBE-BASED) TRAJECTORY. FOR THIS FORMULATION, WE STUDY CONDITIONS THAT CAN YIELD THE CONSTRAINED OPTIMAL CONTROL PROBLEM ASSOCIATED TO THE SET-VALUED MPC FORMULATION FEASIBLE AND STABLE, THUS EXTENDING EXISTING STABILITY RESULTS FROM CLASSIC MPC TO A SET-BASED APPROACH. EXAMPLES ILLUSTRATE THE RESULTS ALONG THE PAPER.

DURING THE LAST DECADE, ENGINEERING PROGRAMS IN CHILE HAVE SHIFTED THEIR FOCUS FROM A TRADITIONAL CONTENT-BASED EDUCATION MODEL TO A COMPETENCY-BASED ONE. ALTHOUGH THIS APPROACH HAS BECOME POPULAR AND INTEGRATED INTO ENGINEERING PROGRAMS, ITS EFFECTIVENESS HAS NOT BEEN FULLY VALIDATED. IN PARTICULAR, CURRENTLY THERE ARE NO TOOLS THAT ALLOW VERIFYING COMPLIANCE WITH THE COMPETENCIES DECLARED IN THE PROFESSIONAL AND BACHELOR'S DEGREE PROGRAMS OFFERED BY THE ENGINEERING COLLEGE AT THE UNIVERSIDAD DEL BÍO-BÍO. IN THIS PROJECT, A SURVEY-TYPE INSTRUMENT IS VALIDATED FOR THE EVALUATION OF ACQUIRED GRADUATE COMPETENCIES, DEFINED IN ENGINEERING PROGRAMS AT UNIVERSIDAD DEL BÍO-BÍO. HERE, VALIDATION WAS CARRIED OUT CONSIDERING STUDENTS FROM INDUSTRIAL AND ELECTRICAL CIVIL ENGINEERING PROGRAMS. ONCE THE INSTRUMENT VALIDITY WAS VERIFIED, IT WAS APPLIED TO DETERMINE THE LEVEL OF FULFILLMENT OF THE COMPETENCIES ACQUIRED AT THE BACHELOR OF SCIENCE IN ENGINEERING LEVEL. OBTAINED RESULTS WERE ANALYZED TO IDENTIFY EXISTING GAPS IN THE CURRICULUM WITH RESPECT TO THE SKILLS EXPECTED FROM GRADUATES, THUS DETECTING DIFFERENT DEGREES OF PROGRESS ACHIEVED AND OPPORTUNITIES FOR IMPROVEMENT. THE FINDINGS OF THIS STUDY INDICATE THAT, BOTH SPECIFIC AND GENERIC COMPETENCIES AT THE BACHELOR OF SCIENCE LEVEL ARE WITHIN ACCEPTABLE RANGES, SINCE THEY ACHIEVED SCORES ABOVE 85%.

WIND ENERGY GAINS INTEREST DUE TO THE DIVERSIFICATION AND DECARBONIZATION OF THE ENERGY MATRIX TO LEAVE BEHIND THE USE OF FOSSIL FUELS THAT CONTRIBUTE TO GLOBAL WARMING. OBTAINING ENERGY FROM THE WIND IS COMPLEX, SINCE WIND ENERGY HAS A VARIABILITY THAT STRONGLY AFFECTS THE QUALITY OF THE ENERGY GENERATED, IN ADDITION, THE WIND TURBINE HAS NON-LINEAR CHARACTERISTICS THAT MAKE THE CONTROL STAGE EVEN MORE DIFFICULT. VARIOUS TECHNIQUES ADDRESS THIS ISSUE, AND ACCLIMATIZATION IS REQUIRED. THIS WORK PRESENTS THE PITCH CONTROL DESIGN METHODOLOGY FOR A LARGE CAPACITY WIND TURBINE. LINEARIZED DYNAMICS AND MPC CONTROLLER ARE USED TO MANAGE THE PITCH ANGLE OF THE WIND TURBINE. THE RESULTS ARE VALIDATED WITH REAL DATA FROM SOUTHERN CHILE AND SHOW ACCEPTABLE RESULTS FOR POWER SMOOTHING. THE OBTAINED RESULTS HELP TO UNDERSTAND THE EFFECTS OF CONSTRAINTS ON THE CONTROL STRATEGY AND ITS PERFORMANCE IN PRACTICAL APPLICATIONS, THUS EMPHASIZING THE NEED FOR APPROPRIATE METHODS FOR NONLINEAR SYSTEMS CONTROL.