Experimental verification of auto carrier car strength calculation

U radu je dat proračun i eksperimentalna analiza naponskog stanja noseće strukture vagona za prevoz automobila. Proračunom je obuhvaćena statička i dinamička analiza noseće strukture, kao i određivanje torzione krutosti primenom metode konačnih elemenata. Analiza čvrstoće noseće strukture je obuhvatila i opterećenje pod dejstvom bočne sile nastale usled ubrzanja od 0,1 g. Analizirana je četvrtina vagona sa bočnim vratima, kao najslabiji deo strukture. Ispitivanjem je obuhvaćena noseća struktura vagona koja se sastoji od postolja, bočnih stranica i dve pokretne platforme, bez čeonih i bočnih vrata kao i krova. Naponi su mereni pomoću mernih traka na 120 mernih mesta, od kojih su pojedina omogućavala merenje napona u sva tri pravca. Rezultati merenja pokazuju da su naponi u svim slučajevima opterećenja značajno ispod dozvoljenih. Zaostali naponi su bili u dozvoljenim granicama. Ugibi noseće strukture su bili veoma mali i nisu prešli 0,6 ‰ rastojanja osa svornjaka, što je značajno ispod dozvoljene vrednosti.In this paper a calculation method and experimental analyses of auto carrier car bearing structure strength are shown. The calculation includes both the static and dynamic analyses of the bearing structure; also the determination of the car body torsion rigidity calculation has been performed with the programming package based on Finite Element Method. The analyses of the bearing structure strength for the load case due to the car lateral inertia forces at lateral acceleration of 0,1.g has also been included. The calculation covered one quarter of the wagon with two doors as the weaker ones. The object tested was the auto carrier car composed of the underframes, sidewalls and two mobile upper platforms without side and front doors and without roof. Stresses were measured by the strain-gauge method on 120 measuring points. Some of them were connected to form strain gauges in three directions thus enabling the estimation of principal stresses. The measuring results show that the stress conditions in all load cases are remarkably under the allowable stresses. The residual stresses were in acceptable limits. Bearing structure deflections were very small and did not exceed 0,6‰ from the centre pin distance, which is well below allowable value

Izolirano desnostrano srčano zatajenje u bolesnice s hipertireozom

Hyperthyroidism has many characteristic manifestations of various organ systems. Cardiovascular effects are frequent in these patients. A less known complication of hyperthyroidism is reversible rightsided heart failure and pulmonary hypertension. In the patient presented, the symptoms of atrial fibrillation and right-sided heart failure were the first manifestations of hyperthyroidism. Doppler echocardiography confirmed pulmonary hypertension. Other secondary reasons for pulmonary hypertension were excluded. Graves\u27 disease was the only reasonable choice. The treatment of hyperthyroidism resulted in conversion in sinus rhythm, withdrawal of symptoms and signs of right-sided heart failure, and normalization of pulmonary artery pressure.Hipertireoza dovodi do mnogo karakterističnih manifestacija na različitim organskim sustavima. Promjene na kardiovaskularnom sustavu često se susreću kod ovih bolesnika. Manje poznata komplikacija hipertireoze je reverzibilno zatajenje desnog srca i plućna hipertenzija. Prikazuje se bolesnica kod koje je prvi znak hipertireoze bila atrijska fibrilacija i zatajenje desnog srca. Doplerovim ehokardiografskim pregledom potvrđena je i plućna hipertenzija. Drugi mogući razlozi plućne hipertenzije su isključeni, tako da je Gravesova bolest ostala kao jedino moguće objašnjenje. Liječenje hipertireoze je rezultiralo konverzijom u sinusni ritam, povlačenjem simptoma desnostranog zatajenja srca i normalizacijom plućnog arterijskog tlaka

Experimental verification of auto carrier car strength calculation

U radu je dat proračun i eksperimentalna analiza naponskog stanja noseće strukture vagona za prevoz automobila. Proračunom je obuhvaćena statička i dinamička analiza noseće strukture, kao i određivanje torzione krutosti primenom metode konačnih elemenata. Analiza čvrstoće noseće strukture je obuhvatila i opterećenje pod dejstvom bočne sile nastale usled ubrzanja od 0,1 g. Analizirana je četvrtina vagona sa bočnim vratima, kao najslabiji deo strukture. Ispitivanjem je obuhvaćena noseća struktura vagona koja se sastoji od postolja, bočnih stranica i dve pokretne platforme, bez čeonih i bočnih vrata kao i krova. Naponi su mereni pomoću mernih traka na 120 mernih mesta, od kojih su pojedina omogućavala merenje napona u sva tri pravca. Rezultati merenja pokazuju da su naponi u svim slučajevima opterećenja značajno ispod dozvoljenih. Zaostali naponi su bili u dozvoljenim granicama. Ugibi noseće strukture su bili veoma mali i nisu prešli 0,6 ‰ rastojanja osa svornjaka, što je značajno ispod dozvoljene vrednosti.In this paper a calculation method and experimental analyses of auto carrier car bearing structure strength are shown. The calculation includes both the static and dynamic analyses of the bearing structure; also the determination of the car body torsion rigidity calculation has been performed with the programming package based on Finite Element Method. The analyses of the bearing structure strength for the load case due to the car lateral inertia forces at lateral acceleration of 0,1.g has also been included. The calculation covered one quarter of the wagon with two doors as the weaker ones. The object tested was the auto carrier car composed of the underframes, sidewalls and two mobile upper platforms without side and front doors and without roof. Stresses were measured by the strain-gauge method on 120 measuring points. Some of them were connected to form strain gauges in three directions thus enabling the estimation of principal stresses. The measuring results show that the stress conditions in all load cases are remarkably under the allowable stresses. The residual stresses were in acceptable limits. Bearing structure deflections were very small and did not exceed 0,6‰ from the centre pin distance, which is well below allowable value

Da li je opadanje neminovno? - nekoliko argumenata protiv

In the article, the authors challenge the main arguments regarding the inevitability of decline of the American power pointed out by the declinists. By citing the eight arguments against declinists' case, the aim is to show that in international relations there is no absolute certainty that something will happen that way most people expect, especially when assessing one's strength. Conventional wisdom often fails in front of the unpredictability of events and the determinism in international relations does not have it easy as in some other areas of human activity.U ovom radu autori dovode u pitanje glavne argumente deklinista u pogledu neminovnosti opadanja američke moći. Navodeći osam argumenata protiv deklinističkih učenja, cilj rada je da se pokaže da u međunarodnim odnosima, pogotovo u pogledu procene nečije moći ne postoji apsolutna sigurnost da će se nešto desiti onako kako to najveći broj ljudi očekuje. Konvencionalne mudrosti često znaju da pokleknu pred nepredvidivostima dešavanja a determinizam u međunarodnim odnosima ima mnogo teže uslove za život nego što je to slučaj u nekim drugim oblastima ljudskog delovanja

Od Sputnjika do Lenova - šest talasa američkog deklinizma posle Drugog svetskog rata

In this paper, the authors examine different waves of American declinism, since the Second World War. In the first part of the paper, he gives a description of the first five waves of American declinism, from the mid-fifties in the last century, and by the end of the Cold War. In the second part, he presents the latest phase of American decline, and displays similarities and differences between the present and past moments.U ovom radu autori propituju različite talase američkog deklinizma, od Drugog svetskog rata na ovamo. U prvom delu rada dat je opis prvih pet talasa američkog deklinizma, od sredine pedesetih godina prošlog veka, pa do kraja Hladnog rata. U drugom delu rada prikazana je najnovija faza američkog opadanja, kao i sličnosti i razlike između današnjeg trenutka i momenata kroz koje su Sjedinjene Američke Države već prošle

Uzburkanost u globalnoj politici - od međudržavnog poretka do globalnog društva

International order, almost unchanged during first three centuries of its existence, has been founded on the balance of power, diplomacy, alliances international law, and after a certain amount of time, on international organizations as its key factors and subjects. Within such order, sovereign and independent states in circumstances of non-existence of basic power that is, in the circumstances of anarchy but not chaos, do acknowledge and accept joint standards of behavior and activities. It is possible to talk about political, diplomatic, legal, economical and military side of a certain international order: since the notion 'international system' is most often used as a synonym for the notion 'order', it is necessary to point out that the 'order', in contrast to the 'system' implies also certain adopted rules of behavior and joint values. as its characteristic trait, alongside with international activities. Each order is system at the same time. On the other hand, there is a question whether, and to what extent, there are relations reflecting social and international order within a certain system. The international order among the states, in particular in last couple of decades, has been infiltrated deeply into the width of global society in statu nascendi, gaining an amorphous shape along the way - there are at least two orders existing and fighting for gaining advantage - one is an order with the states as main subjects, relying on the power balance; the polar power order (not excluding hegemonic and imperial structure of power) and various models of collective security on one side, and on the other side, there is a world order with individuals as its main subjects, that is founded on ideas, norms, values and institutions supporting them; the order of human security and human rights; the rich network of global management being based on new relation toward former dominance of political aspect over economical and environmental one.Gotovo neizmenjen u prva tri veka postojanja, međunarodni poredak se temeljio na ravnoteži snaga, diplomatiji, savezima, međunarodnom pravu i, nešto kasnije međunarodnim organizacijama kao svojim ključnim činiocima i subjektima. U jednom takvom poretku, suverene i nezavisne države u uslovima nepostojanja središnje vlasti - anarhije ali ne i haosa - ipak prihvataju i priznaju zajedničke standarde ponašanja i međudejstva. Može se govoriti o političkoj diplomatskoj, pravnoj, ekonomskoj i vojnoj strani određenog međunarodnog poretka - budući da se kao sinonim poretku najčešće upotrebljava pojam međunarodni sistem, neophodno je kazati da poredak za razliku od sistema podrazumeva kao svoju posebnost, pored postojanja međudejstva država, još i usvojena pravila ponašanja i zajedničke vrednosti. Svaki poredak je istovremeno i sistem; s druge strane, osnovano je pitanje da li, i koliko, u određenom sistemu ima odnosa koji odlikuju društveni i međunarodni poredak. Međunarodni poredak država, posebno u nekoliko poslednjih decenija, sve dublje uranja u širine globalnog društva in statu nascendi dobijajući pri tome amorfan oblik: uporedo postoje i bore se za pretežnost najmanje dva poretka poredak čiji su glavni subjekti države i koji je oslonjen na ravnotežu snaga polaran raspored moći (ne isključujući pri tome i hegemonsku i imperijalnu strukturu moći) i različite oblike kolektivne bezbednosti na jednoj strani kao i svetski poredak sa pojedincima kao glavnim subjektima utemeljen u idejama, normama, vrednostima i institucijama koje ih pridržavaju, poredak ljudske bezbednosti i ljudskih prava, guste mreže globalnog SPM broj 4/2008 godina XV, sveska 22. str. 11-30. 30 upravljanja koji počiva na novom odnosu do tada preovlađujućeg političkog nad ekonomskim i okolinskim, na drugoj strani

Još jedanput o 'Četiri velike debate' - crtice iz istorije nauke o međunarodnim odnosima

Although majority of researchers think that there is a high level of consensus among scientists regarding history of this scientific discipline and its developmental phases, paradoxically enough, there is one problem with that fact itself. It is increasingly becoming evident that on one side there is a gap between a myth created by repeating one and the same thesis for decades, and real history on the other side, with its open issues and contradictions. Despite the belief that some thesis regarding creation and development of 'the field of international relations' have become generally accepted, a number of the scientists re-writing history of this scientific discipline has been constantly increasing, equally in terms of the broad background of international relations and the stances of certain states. In this case not only the search for the truth is the propellant for the researching efforts, but very often it is easy to recognize within these attempts also motivation to confirm or disaffirm the stances in current ongoing debates, through various elucidations of the processes or the stances of some well-known theoreticians and active participants in international politics. It is also important to underline that frequent and uncritical connecting of the stances of various coryphaeus of political theory and philosophy has often inflicted harm to positive contributions of theoreticians of international relations. Certainly it is difficult to deny any connection or foundations of modern theory of international relations whatsoever in the stances of one Tukidides, Plato, Aristotle or medieval and early modern political theoreticians such as Thomas Hobbes, Macchiavelli, Boden... However, unquestionable value of their contemplative sphere would not be significantly acknowledged without taking into account the background of the activities of numerous historians, philosophers or theologists. Not to mention some light research of ancient history, even some distortion of certain stances for purpose of winning the points in current ongoing debates.Iako većina istraživača smatra da postoji visok stepen saglasnosti kad je reč o istoriji discipline i njenim razvojnim fazama, paradoksalno upravo u toj činjenici leži problem. Sve je vidljiviji, naime, jaz između onoga što je višedecenijskim ponavljanjem postalo gotovo mit s jedne, i stvarne istorije sa svim njenim otvorenim pitanjima i protivrečnostima, s druge strane. Uprkos verovanju kako su stvari povodom nastanka i razvoja 'oblasti međunarodnih odnosa' opštepoznate, broj onih koji iznova pišu istoriju discipline neprestano raste; podjednako sa nivoa ukupnih međunarodnih odnosa i iz uglova pojedinih država. Nije u svakom od ovih slučajeva samo traganje za istinom pokretač istraživačkih napora: neretko se u takvim pokušajima lako raspoznaje i interes da određenim tumačenjima procesa i stavova istaknutih teoretičara i praktičara međunarodne politike budu potvrđena ili opovrgnuta stanovišta u aktuelnim raspravama. Važno je ovde reći i to da je prečesto i nekritičko dovođenje u vezu stavova korifeja političke teorije i filozofije često išlo na štetu doprinosa koji su pružali upravo teoretičari samih međunarodnih odnosa. Teško je, razume se, poricati bilo kakvu vezu i utemeljenost savremene teorije međunarodnih odnosa u stavovima jednog Tukidida, Platona, Aristotela ili novovekovnih veličina u oblasti političke teorije kao što su Hobs, Makijaveli, Boden,... ipak, bez uzimanja u obzir okolnosti u kojima su delovali brojni istoričari, filozofi ili teolozi, nesumnjiva vrednost njihovih misaonih dometa neće danas imati veliku saznajnu težinu. Da i ne govorimo o olakom posezanju u daleku istoriju, čak i iskrivljavanju pojedinih stavova kako bi što bolje poslužili svrsi tekućih nadgornjavanja

An application of a hybrid intelligent system for diagnosing primary headaches

[Abstract] (1) Background: Modern medicine generates a great deal of information that stored in medical databases. Simultaneously, extracting useful knowledge and making scientific decisions for diagnosis and treatment of diseases becomes increasingly necessary. Headache disorders are the most prevalent of all the neurological conditions. Headaches have not only medical but also great socioeconomic significance. The aim of this research is to develop an intelligent system for diagnosing primary headache disorders. (2) Methods: This research applied various mathematical, statistical and artificial intelligence techniques, among which the most important are: Calinski-Harabasz index, Analytical Hierarchy Process, and Weighted Fuzzy C-means Clustering Algorithm. These methods, techniques and methodologies are used to create a hybrid intelligent system for diagnosing primary headache disorders. The proposed intelligent diagnostic system is tested with original real-world data set with different metrics. (3) Results: First at all, nine of 20 attributes – features from International Headache Society (IHS) criteria are selected, and then only five most important attributes from IHS criteria are selected. The calculation result based on the Calinski–Harabasz index value (178) for the optimal number of clusters is three, and they present three classes of headaches: (i) migraine, (ii) tension-type headaches (TTHs), and (iii) other primary headaches (OPHs). The proposed hybrid intelligent system shows the following quality metrics: Accuracy 75%; Precision 67% for migraine, 74% for TTHs, 86% for OPHs, and Average Precision 77%; Recall 86% for migraine, 73% for TTHs, 67% for OPHs, Average Recall 75%; F1 score 75% for migraine, 74% for TTHs, 75% for OPHs, and Average F1 score 75%. (4) Conclusions: The hybrid intelligent system presents qualitative and respectable experimental results. The implementation of existing diagnostics systems and the development of new diagnostics systems in medicine is necessary in order to help physicians make quality diagnosis and decide the best treatments for the patients.Ministerio de Ciencia e Innovación; MINECO-TIN2017-84804-RGobierno del Principado de Asturias; FCGRUPIN-IDI/2018/000226Serbia. Ministry of Education, Science and Technological Development; 451-03-68/2020-14/20015

Experimental and numerical determination of tube collision energy absorbers characteristics

Razvoj apsorbera energije sudara je jedna od neophodnih mera pasivne zaštite putničkih vagona. Uloga pasivne zaštite je da posledice sudara svede na najmanju moguću meru. Apsorber razvijan u ovom radu sastoji se od čeličnih bešavnih cevi u kvalitetu P235T1 i konusne čaure napravljene od čelika za poboljšanje u kvalitetu C45E. Tokom sudara provlačenjem cevi kroz konusnu čauru dolazi do redukcije - smanjenja prečnika cevi pri čemu se troši energija. U radu su analizirani rezultati dobijeni numeričkim simulacijama i dinamičkim ispitivanjima cevnih apsorbera kinetičke energije sudara putničkih vagona. Glavni cilj rada je uspostavljanje korelacije rezultata dobijenih numeričkim simulacijama i eksperimentalnim istraživanjima. Korišćenjem karakterističnih parametara dobijenih tokom kvazi-statičkih, dinamičkih ispitivanja i numeričkih simulacija, definisane su vrednosti ključnih parametara koje se mogu koristiti za buduća ispitivanja cevnih apsorbera ovog tipa pri brzinama većim od 20 km/h. Numeričke simulacije se mogu koristiti u fazi razvoja apsorpcionih elemenata dok je za konačnu ocenu prototipa neophodno uraditi dinamička ispitivanja.Development of collision energy absorbers is one of the necessary measures for passive safety of passenger coaches. The purpose of passive safety is to minimize the collision consequences for passengers. The collision absorber developed in this work consisted of a low carbon seamless steel tube and conical bush fabricated from quench and tempered carbon steel. During collision, the seamless tube is compressed into a bush with a reduced diameter. In this paper, the analysis of results is obtained by numerical simulations and dynamic investigation of tube absorbers of kinetic collision energy of passenger coaches. The research focuses on correlations between numerical and dynamic test results. Using the characteristic parameters obtained by the dynamic tests and numerical simulations, values for key numerical parameters have been defined, which can be used for further investigations of tube shrinking absorber. Numerical simulations should be used in the developing phase of a prototype, while for the final verification it is necessary to do dynamic (impact) test

Experimental and numerical determination of tube collision energy absorbers characteristics

Razvoj apsorbera energije sudara je jedna od neophodnih mera pasivne zaštite putničkih vagona. Uloga pasivne zaštite je da posledice sudara svede na najmanju moguću meru. Apsorber razvijan u ovom radu sastoji se od čeličnih bešavnih cevi u kvalitetu P235T1 i konusne čaure napravljene od čelika za poboljšanje u kvalitetu C45E. Tokom sudara provlačenjem cevi kroz konusnu čauru dolazi do redukcije - smanjenja prečnika cevi pri čemu se troši energija. U radu su analizirani rezultati dobijeni numeričkim simulacijama i dinamičkim ispitivanjima cevnih apsorbera kinetičke energije sudara putničkih vagona. Glavni cilj rada je uspostavljanje korelacije rezultata dobijenih numeričkim simulacijama i eksperimentalnim istraživanjima. Korišćenjem karakterističnih parametara dobijenih tokom kvazi-statičkih, dinamičkih ispitivanja i numeričkih simulacija, definisane su vrednosti ključnih parametara koje se mogu koristiti za buduća ispitivanja cevnih apsorbera ovog tipa pri brzinama većim od 20 km/h. Numeričke simulacije se mogu koristiti u fazi razvoja apsorpcionih elemenata dok je za konačnu ocenu prototipa neophodno uraditi dinamička ispitivanja.Development of collision energy absorbers is one of the necessary measures for passive safety of passenger coaches. The purpose of passive safety is to minimize the collision consequences for passengers. The collision absorber developed in this work consisted of a low carbon seamless steel tube and conical bush fabricated from quench and tempered carbon steel. During collision, the seamless tube is compressed into a bush with a reduced diameter. In this paper, the analysis of results is obtained by numerical simulations and dynamic investigation of tube absorbers of kinetic collision energy of passenger coaches. The research focuses on correlations between numerical and dynamic test results. Using the characteristic parameters obtained by the dynamic tests and numerical simulations, values for key numerical parameters have been defined, which can be used for further investigations of tube shrinking absorber. Numerical simulations should be used in the developing phase of a prototype, while for the final verification it is necessary to do dynamic (impact) test