Mehatronički sustav automatkog mjenjača s dvostrukom spojkom i mehaničkim aktuatorom

U ovom radu se opisuje automatski mjenjač s dvostrukom spojkom koji ostvaruje kontinuirani prijenos snage poput planetarnog automatskog mjenjača, te istovremeno ima visok stupanj korisnosti poput ručnog mjenjača. Prvo je opisana kinematska struktura i princip rada automatskog mjenjača s dvostrukom spojkom. Zatim su detaljnije opisani elementi mjenjača relevantni za njegovu regulaciju. Neki dijelovi mjenjača su opisani pomoću dijelova konvencionalnog ručnog mjenjača te su napomenute razlike. Nakon toga se daje pregled metoda upravljanja u situacijama kod pokretanja vozila, rada o odabranom stupnju prijenosa te izmjeni stupnja prijenosa. Na kraju su opisane metode regulacije kojima postižemo željena stanja

Einsteinova sinkronizacija i konvencionalnost istovremenosti

Unatoč naslovu koji pokriva iznimno opširno područje, članak se usredotočuje na blisko pitanje da li Specijalna teorija relativnosti (STR) nužno zagovara ukidanje ontološke razlike između prošlih i budućih događaja, između prošlosti i budućnosti općenito. Izraženo žargonom koji uvodi Stein: jesmo li u okviru STR prinuđeni birati isključivo između ‘solipsizma’ i ‘determinizma’? Posebice će biti riječi o ulozi koju konvencionalnost istovremenosti u STR ima u pokušaju odgovora na ovo pitanje. Standardni argumenti pozivaju se na relativnost istovremenosti, tvrdnju da STR negira postojanje univerzalne ‘sadašnjosti’ koja razgraničava ‘prošlost’ i ‘budućnost’, kako bi pokazali da nema ontološke razlike između prošlosti i budućnosti, da su obje jednako određene/zbiljne (determinizam). Pritom se prešutno prelazi preko činjenice da je za uspostavu ontoloških tvrdnji vezanih uz relativnost istovremenosti potrebno prvo riješiti pitanje konvencionalnosti istovremenosti u okviru STR. U članku će se nastojati pokazati da promatranjem pitanja konvencionalnosti istovremenosti iz perspektive ‘čisto filozofskog’ Dummettovog određenja razlike između prošlosti i budućnosti možemo u okviru STR pokušati razviti shvaćanje razlikovanja prošlosti i budućnosti mimo (nepoželjne) stroge ontološke dihotomije ‘solipsizam’/‘determinizam’, ukoliko kriterij koji postavlja STR shvatimo kao epistemički, a ne kao ontološki. (IN ENGLISH: Despite a broad-range title the paper settles for the related issue of whether the Special Theory of Relativity (STR) necessarily advocates the demise of an ontological difference between past and future events, between past and future in general. In the jargon of H. Stein: are we forced, within the framework of the STR, to choose only between ‘solipsism’ and ‘determinism’ exclusively? A special emphasis is placed on the role that the conventionality of simultaneity plays in the STR with regards to this question. The standard arguments rely on the relativity of simultaneity, the claim that the STR negates the existence of a universal ‘present’ that divides the ‘past’ and the ‘future’, so as to conclude that there is no ontological difference between past and future events, that both are equally determined/real (‘determinism’). This often neglects the fact that to establish the ontological claims related to relativity of simultaneity, one must first resolve the issues of conventionality of simultaneity within the STR. The paper will aim to show that by addressing the issue of conventionality from Dummett’s ‘purely philosophical’ determination of the difference between the past and the future, we develop an understanding of the said difference, within the framework of the STR, beyond the (unwanted) strict ontological dichotomy of ‘solipsism/determinism’, given that the criterion that is provided by the STR is understood as epistemic and not ontological.

THE SYNCHRONIZATION OF HOTEL RESERVATION PROCESS THROUGH RATE AND REVENUE MANAGEMENT USING INFORMATION AND COMMUNICATION TECHNOLOGY

Cilj ove doktorske disertacije je teorijski i empirijski prikazati kako je optimizacija hotelske cjenovne politike i politike upravljanja prihodima, kroz strategije upravljanja hotelskom prodajom, postao vrlo kompleksan zadatak. Odabir jasne strategije pozicioniranja cijena uz razvoj tehnologije u vidu hotelskih softverskih rješenja kao i online kanala prodaje u potpunosti determiniraju poslovnu politiku u vidu kreiranja cijena s obzirom na popunjenost kapaciteta. Svrha ove doktorske disertacije očituje se u postavljanju koncepta ‒ vlastitog modela kojim bi se, kako na znanstvenoj tako i na praktičnoj razini, riješila problematika nedovoljne sinkroniziranosti online kanala prodaje s hotelskim softverima. Uz ponuđeni model sinkronizacije online plasmana cijena i rezervacijskih procesa u realnom vremenu među najznačajnijim doprinosima u ovom doktorskom radu ističu se: a) istraživanje koje je autorica provela, a koje uključuje najveće hotelske lance u Hrvatskoj i to kroz 130 hotela te koje jasno prikazuje stanje informacijsko-komunikacijske opremljenosti hotela; b) rezultati t-testa koji prikazuju statistički značajne razlike za sve promatrane tvrdnje unutar subsegmenta individualnoga kanala u usporedbi stranih i domaćih brendova; c) dokazivanje hotelijerima kao stručnjacima, ali i znanstvenoj javnosti koliko je nužno stalno pratiti nove zahtjeve modernoga hotelskog poslovanja kroz razvoj informacijsko-komunikacijske tehnologije kako bi se održala konkurentnost na tržištu. U ovoj doktorskoj disertaciji, u detaljnom istraživanju u kontekstu primjene ICT u online prodaji kapaciteta predloženi su koraci koje hotelijeri trebaju sagledati kroz učinkovitost uporabe tehnoloških rješenja u nastojanju da se poveća prihod po slobodnoj sobi (Revenue Per Available Room – RevPAR) kako bi se utjecalo na razinu isplativosti. Odabir poslovnih strategija na kojima se temelji cijeli proces koncipiranja i postavljanja modela sinkroniziranosti rezervacijskih procesa i procesa plasmana cijena predstavljaju gorući problem hotelijera u vidu sinkroniziranosti kapaciteta objekata u realnom vremenuThe main purpose of this doctoral thesis is to theoretically and empirically show that optimization of hotel rate policy and Revenue Management through hotel sales strategies has become a very complex task. Choosing a clear positioning strategy along with technology development in the form of hotel software solutions as well as online sales channels completely determine business policy in terms of rate mapping according to rooms availability. The use of information and communication technology in hotel business has fundamentally changed how modern hotel business works. The influence of the Internet has completely upgraded the former concept of sales and marketing, business organization as well as booking processes which have become completely dependent on online guests who take over the reservations of former travel agencies. Distribution channels are now reduced to online and offline sales channels. Today, everything is happening right now, and the synchronization of booking processes through cost and revenue management using information and communication technology has become the biggest challenge for hotel owners, as managing rate policies and real-time pricing enable more efficient business performance. As contemporary world trends show that steady growth in online sales has become reality, one of the goals was to prove that investment in online businessis one of the most important formulas for successful hotel business in Croatia (both in the Adriatic or continental Croatia) and in the world. As the crown of this doctoral thesis, the author offered a business model that in real-time allows a synchronized process of rate distribution with reservation processes. The synchronization of the rate distribution processes with reservation processes depend on a large number of stochastic dynamic variables that need to be considered and matched in real time, which is not yet feasible with the use of existing software solutions. Also, the scientific contribution is reflected in a comprehensive research on the aspects of the modernization of sales strategies and information and communication technology conducted by the author, in which 130 hotels in Croatia participated and whose results represent the real state of the ICT development of the Croatian hotel industry. In terms of exponential growth of online sales in total hotel sales, investing in information and communication technology and the use of online sales channels are necessary not only for more successful business but also for survival of the hotel in today's market share. This doctoral thesis aims to highlight the importance of applying and modernizing the latest software solutions in hotel industry. Sales strategies have a direct impact on the forecasts and each change in rates must take into account the impact that this change will have on the forecasts. When planning a strategy for setting a rate policy or revenue management action plans, every responsible person must know when the guests start to book rooms and how this year's booking behaves in relation to the same period last year, or what is this year's result of the booking compared to planned, budgeted figures. In order to deeply analyze the current booking and observe the "black dates" it is necessary to observe and analyze the default period by days. Most commonly, data are analyzed by the hotel by sales channel, by months. It is necessary to always keep an eye on setting up a right rate strategy, especially for an online channel, where hotels should look at the impact of rate competition. BAR (Best Available Rate) rate strategy is part of revenue management that is useful in hotel sales strategies as it guarantees that the guest is offered the lowest rate for each night of stay distributed on the Internet. It is important to understand the perception of the guest according to BAR strategy because the rate policy can be changed several times a day, and the customer always gets the same service for different rate. Therefore, managers need to think about guest perceptions to better manage their rates and at the end to keep revenue at satisfactory levels. Revenue Managers should not offer excessive rate disproportion to ensure that guests have a positive opinion of rates and rate policy, as the rate setting strategy may have a large rate difference for the same service or room, depending on available capacity for the same day. Hotels should pay attention to the implementation of the BAR rate strategy both on their own and on the web sites of all OTA partners with whom they have contracted not to endanger busines with the partners they are committed to by rate parity contracts. The simplest explanation of rate parity is to maintain consistent rates for the same room across all online distribution channels, regardless of the amount of commissions. Each OTA partner requires rate parity and violation of this contractual policy may result in the hotel being penalized if there is a lower rate somewhere on the Internet. Through new technologies, such as social media (Facebook, Twitter, Instagram, blogs and reviews ...), guests have the ability to share information, search for a destination by rating and leave comments on the quality of the service at the destination or individual hotel. Therefore, today's guests have cards in their hands because of negative comments on social networks which may well harm the reputation of the hotel. All IT specialists as well as hotel staff aim to reduce their manual entry, either from reservation processes or rate changes online, focusing on real-time changes. It is important for the hotel's staff to have updated rates, the exact status of the capacity up to the room types. This connection is called ARI (Availability, Rates, and Inventory). If the ARI connection is not well set up and synchronized to the maximum as current technology allows, there is a risk of overbookings as well as rate parity violations. Online trends consist of last minute reservations. Regardless of all the Revenue Management tools used by hotels today, the insecurity of the bookings,regardless of online sales growth, has never been higher because OTA partners dictate rules where cancellation policies are reduced to 24 hours before guest arrival, reservations are no longer guaranteed with credit cards. In the past, weather forecast did not affect the bookings as rooms were not booked last minute and cancelation policies were very strict. Bad weather forecasts result in massive cancelations and that is why it is important to try to strengthen the allotment, group and MICE sales channels to reduce the risks. Revenue Management Software Solutions are systems that help Revenue Management departments make decisions based on detailed cost, competition, ARI analysis and tips to get the best possible business results. One of the goals of the doctoral dissertation was to prove to hospitality experts as well as to the scientific public that it is necessary to constantly monitor market demands and to evaluate which investments must be made in order to maintain market competitiveness and, if possible, improve one. The main goal of this doctoral thesis is to create authors concept - model, which would solve the problem of insufficient synchronization of online hotel sales channels with hotel property management systems on a scientific and practical level. The synchronization of hotel reservation process through rate and revenue management model consists of five modules that allow a two-way connection, communication from the hotel to the guest and vice versa, a smooth flow from ARI connection on one side; and guest’s reservations confirmation on the other side. With the offered model of online rate distribution and reservation process synchronization in real time, the most significant scientific contributions to this doctoral thesis are: a) the research carried out by the author, which includes the largest hotel chains in Croatia, through 130 hotels, which clearly shows the state of information and communication technology of the hotel; b) T-test results showing statistically significant differences for all observed claims within the subsegment of the individual sales channel compared to foreign and domestic brands; c) Proving to hoteliers as experts as well as to the scientific public that it is necessary to keep up to date with the new requirements of a modern hotel business trends through the development of information and communication technology in order to maintain market competitiveness. In a detailed research in the context of ICT application in the online rate distribution, the author has suggested steps that hoteliers should look through when implementing or using technology solutions in the effort to increase Revenue per Available Room (RevPAR) to influence the level of profitability. Choosing business strategies based on the entire process of designing and setting up a synchronized model of hotel reservation processes and rate distribution is a huge challenge for hotel owners in terms of synchronizing Property Management Systems and online rate distribution in real-time

Nizovi aktivnih antena s transformatorom impedancije i tranzistorskim oscilatorom spregnuti u ravninama E i H

A patch antenna integrated with a transistor oscillator and a line impedance transformer has been used as a building element for two-element power combining arrays. Arrays coupled in E and H planes have been theoretically and experimentally investigated. The inter-element distance in the arrays has been optimized to obtain in-phase operation and mutual injection locking. High EIRP and excellent power combining efficiency are measured. The measured spectra are clean and stable. Electronic beam scanning is demonstrated. The co-polarization and cross-polarization radiation patterns are measured for the case of broadside radiation and scanned positions of the main beam. The cross-polarization levels are low.Mikrotrakasta patch antena unutar koje je ugrađen tranzistorski oscilator i linijski transformator impedancije osnovni je element antenskih nizova za prostorno slaganje snage koji su prikazani u ovom radu. Projektirani su i pokusima ispitani antenski nizovi od dva elementa. Elementi su jednom spregnuti u ravnini E, a drugi puta u ravnini H. Udaljenost između elemenata antenskih nizova je optimizirana tako da bi se postigao željeni koeficijent sprege i međusobna sinkronizacija. Mjerenjima je utvrđena visoka razina zračene snage i iznimno dobra djelotvornost prostornog slaganja snage. Pokusima je potvrđen stabilan rad oba antenska niza i izmjeren je čist spektar. Prikazana je i mogućnost elektroničkog zakretanja glavnog snopa zračenja. Izmjereni su dijagrami zračenja osnovne i križne polarizacije za oba niza u slučaju zračenja okomito na os niza kao i u oba zakrenuta položaja glavnog snopa zračenja. Mjerenja su pokazala niske razine križne polarizacije

Sinkronizacija estrusa visokomliječnih krava

This study was conducted to compare a recent method for oestrus synchronization in lactating dairy cows using PGF2α (P), GnRH (G) and estradiol cypionate (ECP). Four treatments were performed on sixty dairy cows. In treatment 1-PP (twice prostaglandin), cows received two injections of PGF2α on days 0 and 11 (n=14). In treatment 2-PGP (prostaglandingonadotropin- prostaglandin), cows were injected twice with PGF2α, on days 0 and 11 and 100 ug of GnRH on day 3 after the 1st injection (n=14). In treatment 3-PGPE-0 (prostaglandin-gonadotropin-prostaglandin-estradiol-0), cows were treated with PGP and 1 mg of ECP at the same time of 2nd PGF2α injection (n=16). In treatment 4-PGPE-1 (prostaglandin-gonadotropinprostaglandin- estradiol-1), cows were treated with PGP and 1 mg of ECP one day after 2nd PGF2α injection (n=16). The cows were examined rectally and ultrasonographically. Every cow was blood sampled at selected intervals for progesterone and estradiol assay and inseminated at oestrus. After 1st PGF2α injection, a higher percentage of ovulated cows observed with PGP than PP treated cows (64.3 % vs 50 %; P<0.05). The GnRH-treated cows tended to have a larger mature follicle present at 2nd PGF2α injection (71.4 %) than none treated ones (50 %). Two days after 2nd PGF2α injection, cows treated with PGP had a higher peak preovulatory concentrations of estradiol compared to PP treated cows (3.2 ± 0.48 vs 2.6 ± 0.45 pg/mL). Additionally, cows treated with ECP (PGPE-0 and PGPE-1) had a higher peak preovulatory concentrations of estradiol (6.3 ± 0.43 and 6.99 ± 0.63 pg/mL; P<0.01); and a higher percentage ovulation (75.0 % and 87.5 %) than the other treated groups (PP or PGP). Submission rates (number of inseminated/total X 100), differed statistically across treatments, especially those treated with ECP, as well as the conception and pregnancy rates observed were higher with the ECP treated cows than the other treatments. In conclusion, PGP protocol seemed to produce more mature follicles and ovulated cows. The combination of ECP and PGP (PGPE-1) enhanced oestrus and increased ovulation, thus it is potentially a new method to routinely synchronize oestrus and ovulation in dairy cows.Istraživanje je provedeno kako bismo usporedili najnovije metode sinkronizacije estrusa krava u laktaciji koristeći PGF2α (P), GnRH (G) i estradiol cipionat (ECP). Koristili smo četiri tretmana na 60 mliječnih krava. U prvom tretmanu - PP (dva puta prostaglandin), kravama je dvaput injiciran PGF2α, nulti i jedanaesti dan (n = 14). U drugom tretmanu -PGP (prostaglandin-gonadotropin-prostaglandin), kravama je dvaput injiciran PGF2α, nulti i jedanaesti dan i 100 ug GnRH treći dan nakon prve injekcije (n = 14). U trećem tretmanu - PGPE-0 (prostaglandin - gonadotropinprostaglandin - estradiol-0), krave su tretirane kao u PGP, uz 1 mg ECP u vrijeme druge injekcije PGF2α (n = 16). U četvrtom tretmanu - PGPE-1 (prostaglandin - gonadotropin - prostaglandin - estradiol-1), krave su tretirane kao u PGP, uz 1 mg ECP jedan dan poslije druge injekcije PGF2α (n = 16). Krave su pregledane rektalno i pomoću ultrazvuka. Svakoj kravi uziman je uzorak krvi u određenim razmacima, za istraživanje koncentracije progesterona i estradiola te su osjemenjene u estrusu. Nakon prve injekcije PGF2α utvrdili smo veći postotak krava s ovulacijom kod PGP u odnosu na PP tretman (64,3 %, odnosno 50 %; P<0,05). Kod krava tretiranih s GnRH češće su utvrđeni veći zreli folikuli prilikom druge aplikacije PGF2α (71,4 %) u usporedbi s netretiranim (50 %). Dva dana poslije druge aplikacije PGF2α, kod krava tretiranih s PGP utvrđena je veća preovulatorna koncentracija estradiola u usporedbi s kravama u PP protokolu (3,2 ± 0,48, odnosno 2,6 ± 0,45 pg/mL). Također, kod krava tretiranih s ECP (PGPE-0 i PGPE-1) utvrđena je veća preovulatorna koncentracija estradiola (6,3 ± 0,43 i 6,99 ± 0,63 pg/mL; P<0,01) i veći postotak ovulacija (75,0 % i 87,5 %) u odnosu na skupine s drugim tretmanima (PP ili PGP). Postotak osjemenjenih krava (broj osjemenjenih/ukupan broj krava x 100), statistički je bio značajno različit između protokola, pogotovo kod krava tretiranih s ECP, kao i razlike za postotak koncepcije i gravidnosti, koje su bile veće kod krava tretiranih s ECP u odnosu na ostale tretmane. Možemo zaključiti da je PGP protokol za posljedicu imao više dozrelih folikula i više krava s ovulacijom. Kombinacija ECP i PGP (PGPE-1) poboljšala je pojavu estrusa i ovulacija te je to potencijalno nova metoda za rutinsku sinkronizaciju estrusa i ovulacije kod mliječnih krava

Sistematizacija gubitaka u proizvodnim procesima

Svrha ovog završnog rada je ukazati na važnost gubitaka (škart, čekanje, nepotrebni transport, previše informacija, zastoja i drugi) u proizvodnim procesima u poduzećima te ih objasniti i sistematizirati. Metodu koju sam pobliže objasnio te primjenio na jednom primjeru (procjena i sistematizacija informacijskih gubitaka u razvoju proizvoda) jest lean (vitka) proizvodnja. Metoda je posebno efikasna na uočavanju i eliminiranju gubitaka u proizvodnim procesima. Na temelju dobivenih rezultata zaključak primjenjene metode (lean proizvodnje) jest kako se eliminacijom gubitaka unaprijeđuje kvaliteta, smanjuje se vrijeme čekanja kao i ukupni troškovi. Cjelokupni zaključak glasi kako sistematizacijom gubitaka određujemo kritična mjesta tj. uska grla proizvodnje te ih je nužno otkloniti kako bi proces doveli do optimuma

Inhaled Medication in Obstructive Pulmonary Disease – Can we Accomplish More?

Inhalacijski lijekovi temelj su učinkovitog liječenja astme i kronične opstruktivne plućne bolesti. Inhalacijska primjena lijeka s pomoću različitih inhalera omogućuje izravnu dopremu lijeka u dišne putove, na mjesto njihova djelovanja, što im omogućuje brz učinak uz manju dozu lijeka i manje sustavnih nuspojava. Uporaba inhalera često je kompromitirana pogreškama pri njihovoj primjeni, koje mogu uzrokovati izostanak plućne depozicije lijeka, u konačnici, značajno lošiji tijek bolesti i nepotreban trošak. Ovaj tekst sažima temeljne postavke primjene inhalacijskih lijekova, navodi značaj pogrešaka pri inhaliranju, ističe važnost trajne edukacije bolesnika, u čemu središnju ulogu ima educiran i motiviran liječnik.Inhaled medication is the basis for effective treatment of asthma and chronic obstructive pulmonary disease. Inhalation using various inhalers enables direct release of the drug into the airways, with in situ action that allows for rapid effect with lower drug dose and fewer overall side effects. The use of inhalers is often compromised by usage errors, which may lead to an absence of pulmonary drug deposition, and ultimately to a notably graver course of the disease and unnecessary costs. This work summarizes the basic postulates of the use of inhaled medication, critical inhaler errors, and the importance of continuous education of patients, in which an educated and motivated physician plays a central role

INFLUENCE OF SEED PRIMING ON GERMINATION OF MARIGOLD (CALENDULA OFFICINALIS L.) IN STRESS CONDITIONS

Neven (Calendula officinalis L.) je poznat po svojim ljekovitim svojstvima kao i primjeni u medicinskoj, kemijskoj, kozmetičkoj i prehrambenoj industriji. Prilagođen je umjerenoj klimi te mu je optimalna temperatura klijanja 20 °C. Klijanje sjemena i rani rast sadnica su najosjetljiviji stadiji na abiotske stresove, kao što su nepovoljna temperatura i suša, a predsjetveni tretmani sjemena pozitivno utječu na svojstva klijavosti ili kvalitetu sjemena i sadnica u stresnim uvjetima. S obzirom da se sjetva nevena obavlja čim se uspostave minimalni uvjeti, a tada temperature i količine oborina mogu biti znatno niže od optimalnih, cilj ovog istraživanja bio je utvrditi utjecaj predtretmana na svojstva klijavosti sjemena nevena u uvjetima niskih temperatura i suše (-0,8 MPa PEG 6000). Laboratorijskim pokusom istražen je utjecaj temperature (14 °C, 18 °C i 22 °C) na klijavost sjemena nevena uz predtretmane dH2O i GA3 (250 ppm) u trajanju od 24 h. Netretirano sjeme je predstavljalo kontrolu. Utvrđeno je da sjeme nevena ne klije u uvjetima suše bez obzira na predsjetveni tretman i na temperaturu pri kojoj je klijalo. Ni temperatura niti predtretman sjemena ne utječu značajno na broj proklijalih sjemenki nevena, ali utječu na brzinu klijanja.Marigold (Calendula officinalis L.) is known for its medicinal properties and is used in the medical, chemical, cosmetic, and food industries. It is adapted to a temperate climate and its optimum germination temperature is 20 °C. Seed germination and early seed ling growth are the most sensitive to abiotic stresses such as unfavourable temperatures and drought, while seed priming has a positive effect on germination properties of seed and seed ling quality under stressful conditions. Since sowing of marigolds is done as soon as the minimum conditions are established, when temperature sand precipitation canbes ignificantly lower than optimal, the aim of this study was to determine the impact of seed priming on the germination properties of marigold seeds under low temperature and drought (-0.8 MPa PEG 6000). The effect of temperature (14 °C, 18 °C, and 22 °C) on germination of marigold seeds with treatments containing dH2O and GA3 (250 ppm) for 24 h was studied under laboratory conditions. Untreated seed represented control. Marigold seeds did not germinate under drought conditions, regard less of seed priming treatments and temperatures. It was also found that neither temperature nor seed priming significantly affected the number of germinated marigold seeds, but did affect the germination rate