Automation a conveyor belt furnace for annealing metals in a protective atmosphere

Abstract The paper presents the revitalization of a conveyor belt furnace for annealing metal, which included the design and implementation of a control system based on a programmable logic controller. The goal of the revitalization of the furnace is its modernization through the digital transformation of technological process variables as a new form of data availability in the context of Industry 4.0. The application of a modern control system ensures optimal control of the technological process and thus significantly extends the useful life of the machine

Control System Design for a Centrifuge Motion Simulator Based on a Dynamic Model

This paper presents a dynamic model-based design of a control system and an approach toward a drive selection of a centrifuge motion simulator (CMS). The objective of the presented method is to achieve the desired performance while taking into account the complexity of the control system and the overall device cost An estimation of a dynamic interaction of the interconnected CMS links motions is performed using the suitable inverse dynamics simulation. An algorithm based on the approximate inverse dynamics model is used within the drive selection method. The model of the actuator's mechanical subsystem includes the effective inertia (inertia reflected on the rotor shaft) calculated from the inverse dynamics model. A centralized control strategy based on a computed torque method is considered and compared to traditional decentralized motion controllers To obtain an accurate comparison of the suggested control methods through a realistic simulation, structural natural frequencies of the manipulator links are considered, and the actuator capabilities are taken into account The control system design and simulation methods and the drive selection strategies, presented here for the CMS, are applicable within the general robot manipulator's domain

RESEARCH ON RISKS SOURCES AND DRIVERS IN ROAD CONSTRUCTION PROJECTS

U specijalističkom radu istraživani su izvori i pokretači rizika na projektima cestogradnje. U projektima se javljaju određeni rizični događaji koji na dobar, a češće na loš način, utječu na uspjeh projekta. Uspjeh projekta znači da je projekt dovršen u ugovorenom roku, u okviru ugovorenih troškova i da je postignuta ugovorena kvaliteta radova. Da bi se smanjili negativni utjecaji na organizacijske procese, neophodno je posvetiti se, posebno na projektima velike ugovorene vrijednosti, upravljanju rizicima koje podrazumijeva aktivnosti praćenja i kontrole vjerojatnosti nastanka rizika i utjecaja različitih događaja na projektne aktivnosti. Identifikacija, analiza i vrednovanje rizika zahtijevaju poznavanje metoda za analizu rizika. U ovome radu primijenit će se kvalitativna analiza, koja koristi podatke kojima se iskazuje i procjenjuje mogućnost gubitka (štete) ili dobiti nastale pojavom rizičnog događaja. Plan istraživanja, odnosno analize izvora rizika i pokretača rizika, proveden je na bazi od 42 projekta cestogradnje koji su izvedeni u periodu od 2012. do 2017. godine. U ovom radu je analiziran i odnos projektnih rizika i elemenata kompetencije upravljanja projektima prema Hrvatskom nacionalnom vodiču za temeljne sposobnosti upravljanja projektima.Specialist thesis has explored the sources and drivers of risks in road construction projects. There are always some risky events that affect the success of a project in a good, and more often, a bad way. The success of a project means that the project is completed within the agreed time and cost frame and that the contracted quality of the works has been achieved. In order to reduce the negative impacts on organizational processes, it is necessary to devote, in particular in projects of high contract value, risk management that implies the activities of monitoring and controlling the likelihood of risk generation and the impact of different events on project activities. Identification, analysis and risk assessment require knowledge of risk analysis methods. In this paper, a qualitative analysis will be used, which uses the data that estimate the possibility of loss (damage) or profit appeared when a risky event appeared. The research plan, apropos the analysis of risk sources and risk drivers, was carried out on the basis of 42 road construction projects which were conducted in the period from 2012 to 2017. In this paper is also an analysis of the relationship between project risks and elements of project management competence according to the NCB

COMPUTED TORQUE CONTROL FOR A SPATIAL DISORIENTATION TRAINER

A development of a robot control system is a highly complex task due to nonlinear dynamic coupling between the robot links. Advanced robot control strategies often entail difficulties in implementation, and prospective benefits of their application need to be analyzed using simulation techniques. Computed torque control (CTC) is a feedforward control method used for tracking of robot’s time-varying trajectories in the presence of varying loads. For the implementation of CTC, the inverse dynamics model of the robot manipulator has to be developed. In this paper, the addition of CTC compensator to the feedback controller is considered for a Spatial disorientation trainer (SDT). This pilot training system is modeled as a 4DoF robot manipulator with revolute joints. For the designed mechanical structure, chosen actuators and considered motion of the SDT, CTC-based control system performance is compared with the traditional speed PI controller using the realistic simulation model. The simulation results, which showed significant improvement in the trajectory tracking for the designed SDT, can be used for the control system design purpose as well as within mechanical design verification

Verificación de conceptos básicos de la teoría de lealtad en el marco de relación dueño-mascota

Glavni je cilj ovog istraživanja bio provjeriti primjenjivost osnovnih koncepata teorije privrženosti u području veza ljudi i njihovih kućnih ljubimaca, odnosno definirati osnovna obilježja spomenutog odnosa u kontekstu privrženosti. Privrženost je u odnosu vlasnik-kućni ljubimac interpretirana u kontekstu bliskih odnosa u okviru obiteljske, romantične i prijateljske domene. U istraživanju je sudjelovalo 219 vlasnika kućnih ljubimaca (pasa), koji su osobno kontaktirani te su pristali popuniti upitnik. Mjerni su instrumenti zastupljeni u primijenjenom upitniku Upitnik karakteristika i funkcija privrženosti, Modificirani Brennanov Inventar iskustava u bliskim vezama i Upitnik privrženosti prema kućnim ljubimcima. U odnosu je s kućnim ljubimcem izražena funkcija separacijske anksioznosti pred sigurnim utočištem kao indikatorom realizacije privrženog ponašanja. Vlasnici pasa percipiraju odnos s romantičnim partnerom kao onaj u kojem je najsnažniji doživljaj sigurnog utočišta, dok je isti najmanje izražen upravo u odnosu s kućnim ljubimcem. Razlike u doživljaju separacijske anksioznosti među odnosima nešto su manje izražene iako prisutne i podržavaju vodeći status partnerskog odnosa. Utvrđen je nizak stupanj konzistencije među dimenzijama privrženosti u odnosima s ljudima i odnosu sa psom kao kućnim ljubimcem. Pojedinci koji su skloniji izbjegavati bliskost i odbijati intimnost vjerojatnije će i realizirati manje privrženih ponašanja u specifičnim odnosima (vrijedi za sve ispitivane vrste odnosa). Istraživanje je pridonijelo definiranju karakteristika odnosa vlasnik-kućni ljubimac jer se njime zahvaća pretpostavljena uloga koju privrženost igra u takvom odnosu. Općenito, rezultati upućuju na zaključak prema kojem odnos s kućnim ljubimcem te odnosi u preostale tri bliske interpersonalne domene dijele u određenoj mjeri zajedničku osnovu, u smislu kvalitete privrženosti, u teorijski očekivanom smjeru. Može se zaključiti da odnos s kućnim ljubimcem imitira blizak interpersonalni odnos.The main purpose of this research was to test the applicability of the basic concepts of the attachment theory in the field of relationship between humans and their pets, i.e. to define the basic features of the aforementioned relationship in the context of attachment. The relationship between the owner and the pet is interpreted in the context of close relationships within a family, romantic and friendly domain. The survey included 219 dog owners, who were personally contacted and who agreed to fill in the questionnaire. The measuring instruments used in the questionnaire were as follows: Attachment Features and Functions Questionnaire, Modified Experiences in Close Relationships Inventory, Attachment to pets questionnaire. In a relationship with a pet, the function of separation anxiety before a safe haven is shown as an indicator of the attached behaviour. A relationship with a romantic partner is perceived by the dog owners as the one with the most powerful experience of a safe haven, while a relationship with a pet is perceived as the least powerful. Differences in the experience of separation anxiety between relationships are somewhat less evident, although they are present and support the leading status of a relationship with a romantic partner. A low degree of consistency among the dimensions of attachment in a relationship with humans and a relationship with a pet has been established. Individuals who are more inclined to avoid closeness and refuse intimacy are more likely to establish fewer attached behaviours in specific relationships (applies to all investigated types of relationships). The research has contributed to defining the characteristics of the relationship between the owner and the pet since it includes the presumed role of the attachment in such a relationship. Generally, the results point towards the conclusion in the theoretically expected direction, which is that the relationship with the pet relates to the remaining three close interpersonal domains in terms of quality of attachment. It can be concluded that the relationship with the pet imitates a close interpersonal relationship.El objetivo principal de este trabajo fue verificar la aplicabilidad de conceptos básicos de la teoría de lealtad en relaciones dueño-mascota, o sea, definir las características básicas de dicha relación en el contexto de lealtad. La lealtad en relación dueño-mascota se ha interpretado en el contexto de relaciones cercanas del dominio familiar, romántico y amistoso. En la investigación participaron 219 dueños de mascotas (perros) contactados personalmente y que aceptaron rellenar el cuestionario. Los instrumentos de medición fueron los siguientes: el Cuestionario de Características y Funciones de Lealtad, el Inventario de Experiencias en Relaciones Cercanas de Brennan modificado y el Cuestionario de Lealtad a las Mascotas. En la relación con la mascota está acentuada la función de ansiedad por separación del refugio seguro como indicador de realización del comportamiento leal. Los dueños del perro perciben la relación con su pareja romántica como la relación que ofrece la sensación más fuerte de refugio seguro, mientras que la misma sensación está menos percibida en la relación con su mascota. Las diferencias en la sensación de ansiedad por separación entre las relaciones están menos expresadas, aunque presentes y apoyando el estatus líder que tiene la relación con la pareja. Se ha determinado un nivel bajo de consistencia entre las dimensiones de lealtad en relaciones con la gente y en relación con el perro como mascota.  Es más probable que las personas que tienden a evitar la cercanía y rechazar la intimidad, que realicen menos comportamientos leales en relaciones específicas (vale para todo tipo de relaciones investigadas). La investigación ha contribuido a definir las características de la relación dueño-mascota ya que cubre también el supuesto papel que la lealtad tiene en este tipo de relaciones. En general, los resultados llevan a la conclusión que la relación con la mascota y las relaciones en otros tres dominios cercanos interpersonales en cierta medida comparten la base, en el sentido de la calidad de lealtad, en la dirección teoréticamente esperada. Se puede concluir que la relación con la mascota imita la relación cercana interpersonal

Provjera osnovnih koncepata teorije privrženosti u okviru odnosa vlasnik-kućni ljubimac

Glavni je cilj ovog istraživanja bio provjeriti primjenjivost osnovnih koncepata teorije privrženosti u području veza ljudi i njihovih kućnih ljubimaca, odnosno definirati osnovna obilježja spomenutog odnosa u kontekstu privrženosti. Privrženost je u odnosu vlasnik-kućni ljubimac interpretirana u kontekstu bliskih odnosa u okviru obiteljske, romantične i prijateljske domene. U istraživanju je sudjelovalo 219 vlasnika kućnih ljubimaca (pasa), koji su osobno kontaktirani te su pristali popuniti upitnik. Mjerni su instrumenti zastupljeni u primijenjenom upitniku Upitnik karakteristika i funkcija privrženosti, Modificirani Brennanov Inventar iskustava u bliskim vezama i Upitnik privrženosti prema kućnim ljubimcima. U odnosu je s kućnim ljubimcem izražena funkcija separacijske anksioznosti pred sigurnim utočištem kao indikatorom realizacije privrženog ponašanja. Vlasnici pasa percipiraju odnos s romantičnim partnerom kao onaj u kojem je najsnažniji doživljaj sigurnog utočišta, dok je isti najmanje izražen upravo u odnosu s kućnim ljubimcem. Razlike u doživljaju separacijske anksioznosti među odnosima nešto su manje izražene iako prisutne i podržavaju vodeći status partnerskog odnosa. Utvrđen je nizak stupanj konzistencije među dimenzijama privrženosti u odnosima s ljudima i odnosu sa psom kao kućnim ljubimcem. Pojedinci koji su skloniji izbjegavati bliskost i odbijati intimnost vjerojatnije će i realizirati manje privrženih ponašanja u specifičnim odnosima (vrijedi za sve ispitivane vrste odnosa). Istraživanje je pridonijelo definiranju karakteristika odnosa vlasnik-kućni ljubimac jer se njime zahvaća pretpostavljena uloga koju privrženost igra u takvom odnosu. Općenito, rezultati upućuju na zaključak prema kojem odnos s kućnim ljubimcem te odnosi u preostale tri bliske interpersonalne domene dijele u određenoj mjeri zajedničku osnovu, u smislu kvalitete privrženosti, u teorijski očekivanom smjeru. Može se zaključiti da odnos s kućnim ljubimcem imitira blizak interpersonalni odnos.</p

Computed torque control for a spatial disorientation trainer

A development of a robot control system is a highly complex task due to nonlinear dynamic coupling between the robot links. Advanced robot control strategies often entail difficulties in implementation, and prospective benefits of their application need to be analyzed using simulation techniques. Computed torque control (CTC) is a feed-forward control method used for tracking of robot's time-varying trajectories in the presence of varying loads. For the implementation of CTC, the inverse dynamics model of the robot manipulator has to be developed. In this paper, the addition of CTC compensator to the feedback controller is considered for a Spatial disorientation trainer (SDT). This pilot training system is modeled as a 4DoF robot manipulator with revolute joints. For the designed mechanical structure, chosen actuators and considered motion of the SDT, CTC-based control system performance is compared with the traditional speed PI controller using the realistic simulation model. The simulation results, which showed significant improvement in the trajectory tracking for the designed SDT, can be used for the control system design purpose as well as within mechanical design verification

Quality of close relations in dog owners and aspects of attachment to the pet

Odnos između vlasnika i njihovih kućnih ljubimaca nema eksplicitno definiranu svrhu, ipak čini se da poprima obilježja obostranog afektivnog odnosa. Ovo je posebice istaknuto kada je riječ o psima kao kućnim ljubimcima, koji osim što su najpopularnija vrsta ljubimaca, ujedno su i vrsta za koju se čovjek snažno emocionalno veže. Istraživanja pokazuju kako u nekim slučajevima kućni ljubimci zamjenjuju manjak veza privrženosti s ljudima, dok u drugima proširuju raspon veza i socijalnih kontakata koji doprinose općem životnom zadovoljstvu te pružaju osjećaj ugode i potpore u težim trenucima. Cilj ovog istraživanja bio je pokušati utvrditi razlikuju li se dvije skupine vlasnika pasa u nekim odrednicama kvalitete bliskih interpersonalnih odnosa uzevši pritom u obzir aspekte privrženosti koje ostvaruju u odnosu sa svojim ljubimcem. Rezultati potvrđuju očekivanja; uzorak vlasnika pasa do kojeg se došlo tehnikom tzv. snježne grude realizira kvalitetnije bliske interpersonalne odnose i iskazuje veće životno zadovoljstvo, dok tzv. samoregrutirani uzorak vlasnika pasa slabije funkcionira u odnosima sa značajnim drugima, a uz to su i manje zadovoljni životom. Nadalje, skupina vlasnika pasa koja je lošija na interpersonalnom planu, privrženija je svom ljubimcu. Njihova motivacija za socijalnim kontaktom istaknuta je u potrebi za pažnjom i samouzdizanjem koje proizlazi iz te pažnje, što upućuje na moguće faktore unutar ličnosti koji bi mogli biti važni za interpersonalno funkcioniranje.Pet ownership does not have an explicitly defined purpose, still it seems to be a mutual affective relation. This is emphasized when it comes to dogs as pets. Dogs are the most popular pet species and people express that they form strong emotional bonds with dogs. Research shows that sometimes pets compensate the lack of human attachment bonds, while in other cases they expand the range of relations and social contacts that contribute to general life satisfaction and give support in stressful moments. The aim of this research was to determine if two samples of dog owners differ in some aspects of quality of close interpersonal relations, considering certain aspects of attachment to their pet dogs. Results confirm the expectations; the sample of dog owners recruited by the snow ball technique reports higher quality of close interpersonal relations as well as higher life satisfaction, while the self-recruited sample of dog owners has weaker quality of relations with significant others and they are less satisfied with their life. Furthermore, the sample of dog owners who form weaker interpersonal bonds are more attached to their pet. Their affiliative motivation is distinguished by the need for attention and following self-praise which points to possible personality factors as relevant for interpersonal functioning

Social Relations, Emotional Relatedness to a Pet and Life Satisfaction in Dog Owners

Istraživanja sustavno potvrđuju tzv. pozitivan efekt ljubimaca na zdravlje i psihofizičku dobrobit njihovih vlasnika. Pritom bi struktura i subjektivni doživljaj socijalne okoline vlasnika mogli biti važni za sam proces razvoja emocionalne bliskosti s ljubimcem. Također, čini se da kvaliteta interpersonalnih odnosa uvjetuje i način na koji će se odnos s ljubimcem odraziti na vlasnikovu dobrobit. Cilj ovog istraživanja stoga je bio provjeriti snagu i smjer povezanosti afektivne vezanosti za ljubimca i životnoga zadovoljstva kod vlasnika ljubimaca, uz kontrolu efekata varijabli socijalne okoline, te analizirati njihove moguće moderirajuće efekte. U istraživanju je sudjelovalo 219 vlasnika pasa koji su ispunili formu upitnika papir-olovka. Uz opće sociodemografske informacije i kratku procjenu socijalne podrške, prikupljeni su i podaci o doživljaju usamljenosti, životnom zadovoljstvu i afektivnoj bliskosti s ljubimcem. Rezultati su pokazali kako je afektivna vezanost za ljubimca pozitivan prediktor zadovoljstva životom kod vlasnika pasa, i to pod uvjetima kada se efekti kvalitete socijalne okoline drže pod kontrolom. Socijalna usamljenost djeluje kao moderator odnosa afektivne vezanosti za ljubimca i životnoga zadovoljstva. Podatke o kvaliteti interpersonalnih odnosa nužno je uključiti u istraživanja implikacija odnosa vlasnik – kućni ljubimac.Empirical findings systematically confirm the positive pet effect on health and psychophysical well-being of pet owners. At the same time, the structure and subjective quality of the owner\u27s social milieu could be important for the development of an emotional bond with a pet. Also, it seems that the quality of interpersonal relations determines the way in which the relationship with a pet is reflected on the owner\u27s well-being. The aim of this research was to investigate the strength and direction of the relation between emotional relatedness to a pet and life satisfaction in pet owners, while controling for effects of variables indicating the owner\u27s social milieu, and also to analyze their possible moderating effects. There were 219 dog owners who completed a paper-pencil questionnaire form. The following data was collected: general sociodemographic information and short estimation of social support, the experience of loneliness, life satisfaction and emotional relatedness to a pet. Emotional relatedness to a pet is a positive predictor of life satisfaction in dog owners, even when effects of the quality of social milieu are controled. Social loneliness is a moderator of the relation between emotional closeness to a pet dog and life satisfaction. Data on interpersonal relations quality are necessary in the research of pet ownership implications