69 research outputs found
SELECTED ASPECTS OF THE TRAIN TIMETABLE CONSTRUCTION OF PASSENGER TRAINS WITH THE CONSIDERATION OF PLATFORM EDGES AND STABLING TRACKS ALLOCATION PROBLEM
The aim of the article is to present a method concerning the problem of the construction of timetable from the point of view of the assignment of platform edges and stabling tracks. Taking into account these two issues in the method is extremely important from the point of view of the fluency of railway traffic, as well as minimizing railway undertaking costs related to access to the infrastructure offered by the manager in terms of occupying the platform edge above the set time. The paper describes the issues of allocating platform edges and stabling tracks in operating offices, with particular consideration of the costs related to this. The formulation of the problem of the train timetable construction was presented, including the allocation of edges and stabling tracks in a mathematical manner. In the model specified those parts that are relevant to the research problem considered in the article. In addition, the algorithm of the construction method with the use of a block diagram was discussed
The Selected Problems of Public Transport Organization Using Mathematical Tools on the Example of Poland
Public transport plays an increasingly important role in satisfying the transport needs. Travellers’ requirements regarding the quality of services are increasing. In addition to passenger comfort, other parameters are important (timetable and the state of transport infrastructure). Therefore, methods that determine the appropriate organization of public transport for an area should be sought. The purpose of the article is to present the most commonly used optimization methods and tools that have been applied to the chosen problems of organization of public transport mainly in Poland (described in the articles of mainly Polish scientists), but against the background of global research. The article characterizes the functioning of public transport in Poland. The selected problems of public transport functioning, which can be solved by using optimization methods and tools were discussed. The chosen methods that were used to formulate and solve the identified problems were indicated. The effects of this article will form part of the work on the POIR.01.01.01-00-0970/17-00 project "IT system for computer-aided public transport planning" financed by the National Centre for Research and Development
Osteochondrosis dissecans of the knee : evaluation of the evolution of MR morphology during treatment
Background: To assess the evolution of MR morphology of OCD lesions in response to treatment and feasibility of MRI as a control study in patients with treated OCD. Material/Methods: 11 patients (6 women and 5 men, aged 11-24 years, average age 17 years) with lesions affecting 12 knee joints were followed for approximately 24.2 months with repeated clinical examination and MR imaging. All MR studies were performed on a 1.5 Tesla unit. MR arthrography was performed in 3 patients. The evolution of MR morphology of the lesions was assessed with a 5-point scale and correlated with the results of clinical assessment with a modified Lysholm scale. Results: In 10 patients, a good clinical result was achieved. In 7 knee joints of patients from this group, the features of the healing of the OCD lesion were observed in MRI and in 4 knees the morphology of the OCD lesion was stable. In 5 MR examinations, a transient deterioration was observed, which in 4 cases preceded healing and in 1 case stabilization in MR morphology. Conclusions: Transient deterioration may be observed in MR studies prior to the healing of OCD lesions irrespective of the improvement in clinical examination. The follow up of patients with OCD should be based mainly on clinical examination, with MR studies reserved for late control or patients with clinical signs of deterioration
Finansyzacja gospodarki krajów Europy Środkowo-Wschodniej
The blurring boundary between the financial and real economy, as well as the growing autonomy of the financial sector have been observed since the late 1970s. This phenomenon has been referred to in literature as financialization. The article presents several definitions of the financialization process, which occupies an important place in the modern economic world. The paper presents the reasons, sources and effects of financialization, followed by a discussion on the right measures of that process. These measures are then used for an empirical study of the degree of financialization in selected Central and Eastern European countries. The analysis led to the conclusion that the scale of the financialization phenomenon in this part of Europe is relatively small, but not completely uniform in individual countries. The scale of financialization in the Czech Republic, Hungary, Estonia, and Poland should be assessed to be rather similar, while Slovak economy is the most resistant to the financialization process.Obserwowana od końca lat siedemdziesiątych XX w. zacierająca się granica pomiędzy finansową i realną sferą gospodarki oraz dokonująca się autonomizacja sektora finansowego spowodowały zainteresowanie się ekonomistów tematyką, określaną w literaturze pojęciem finansyzacji. W artykule dokonano systematyki definicji finansyzacji, zjawiska odgrywającego istotne znaczenie we współczesnym świecie. Wskazano również jego przesłanki, źródła i skutki, a także omówiono wykorzystywane w badaniach mierniki oceny stopnia finansyzacji gospodarki, co dało podstawę do analizy finansyzacji gospodarek w wybranych krajach Europy Środkowo-Wschodniej. Analiza doprowadziła do sformułowania wniosku, że skala tego zjawiska w tej części Europy jest stosunkowo niewielka. Indywidualny poziom mierników wykorzystywanych do oceny tego zjawiska jest zróżnicowany w poszczególnych krajach. Niemniej jednak po ich zagregowaniu skalę finansyzacji gospodarek Czech, Węgier, Estonii i Polski należy oceniać na zbliżonym poziomie. Najbardziej odporna na zjawisko finansyzacji okazała się gospodarka Słowacji.
Osteoblastoma of the femur in a patient with recurrent paronychia : case report
Background: Osteoblastoma is a rare primary benign bone tumor that has varied radiologic presentation depending on the affected site. In selected cases, differential diagnosis with subacute osteomyelitis is necessary. Case Report: The authors present the case of a 23 year-old male with recurrent paronychia diagnosed with osteoblastoma of the femur. On the basis of CT and MRI findings, osteosarcoma, ABC, enchondroma, chondromyxoid fibroma, and Brodie's abscess were excluded from differential diagnosis, with the last option being the second most probable diagnosis given the coexistence of chronic pyogenic process. Discussion: Plain film findings in osteoblastoma and Brodie's abscess may be strikingly similar with an osteolytic lesion surrounded by prominent sclerosis. The nature of the lesion can be further elucidated by cross-sectional imaging. CT helps to assess the lesion matrix and presence or absence of sequestra or fistulae, while MRI defines the extent of the changes in bone marrow cavity and soft tissues
Gas Chromatographic Analysis of Plant and Insect Surface Compounds: Cuticular Waxes and Terpenoids
The value of ultrasonography in the diagnosis of varicocele
A varicocele is described as pathologically enlarged, tortuous veins of the pampiniform plexus, leading to an increased testicular temperature and adrenal metabolite reflux into the testes. Varicocele can impair spermatogenesis and is considered to be the most common cause of male infertility. Patients may palpate a thickening in the scrotum or complain of dull scrotal or inguinal pain, which increases when standing or during erection. In the case of a sudden onset of varicocele in elderly men, it is necessary to exclude renal tumor and extend diagnostic ultrasound with the assessment of the abdominal cavity. The diagnosis of varicocele is based on medical history and physical examination, which involves palpation and observation of the scrotum at rest and during the Valsalva maneuver. Ultrasound is the imaging method of choice. The width and the number of vessels in the pampiniform plexus as well as the evaluation and measurement of regurgitation during the Valsalva maneuver are typical parameters analyzed during ultrasound assessment. However, diagnostic ultrasound is still a controversial method due to numerous and often divergent classification systems for varicocele assessment as well as its poor correlation with clinical manifestations. As a result of introduction of clear ultrasound criteria as well as the development of elastography and nuclear magnetic resonance, diagnostic imaging can play an important role in assessing the risk of damage to the testicular parenchyma, qualifying patients for surgical treatment and predicting the effects of therapy
A deceptive case of emphysematous cholecystitis complicated with retroperitoneal gangrene and emphysematous pancreatitis : clinical and computed tomography features
Purpose: Emphysematous cholecystitis (EC) is an uncommon, severe variant of acute cholecystitis caused by gasforming bacteria - most often Clostridium perfringens and Escherichia coli. We present a deceptive case of EC associated with retroperitoneal gas gangrene and emphysematous pancreatitis. Case report: An 86-year-old, overweight woman was admitted to the emergency department with non-specific abdominal symptoms. Admission laboratory tests showed elevated diastase levels indicating acute pancreatitis. Computed tomography (CT) demonstrated a substantial amount of gas in the retroperitoneum and peritoneal cavity, which raised a suspicion of duodenal perforation. Primary diagnosis was not confirmed during emergency laparotomy, which revealed a gangrenous gallbladder adjacent to the duodenum and surrounded by purulent fluid. The final diagnosis established after laparotomy and rereading of CT scans was that of emphysematous cholecystitis associated with gangrenous pancreatitis and retroperitoneal gangrene. After surgery, the patient was transferred to the intensive care unit in septic shock. Shortly after, the second laparotomy was undertaken on suspicion of internal bleeding. During surgery, the patient experienced cardiac arrest and died despite immediate resuscitation. Conclusions: Emphysematous cholecystitis may be associated with a spread of infection both to the peritoneal cavity and retroperitoneum and result in a substantial amount of gas in those anatomic compartments. The knowledge of this rare complication may be helpful in establishing a correct diagnosis
Scenario analyses for a sustainable transport system development
The paper presents selected aspects of developing sustainable transport system and provides the essential elements of scenario analysis procedure. The scenario analyse permits a background for setting approaches for the development of transport system. A major step towards reliable scenario analyses is establishing a system of criteria and indicators for evaluating the quality of analyse results. The appropriate system of criteria was proposed as a support for decision maker examining variants of transport system development. Scenario analyses require a tool for traffic distribution into transport network under different scenarios of its development. The large scale and detailed transport systems can be investigated with EMITRANSYS model – a new tool for multivariate distribution of traffic flow with regard to ecological, economic and technological criteria
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