This paper concerns the problem of learning control policies for an unknown linear dynamical system to minimize a quadratic cost function. We present a method, based on convex optimization, that accomplishes this task robustly: i.e., we minimize the worst-case cost, accounting for system uncertainty given the observed data. The method balances exploitation and exploration, exciting the system in such a way so as to reduce uncertainty in the model parameters to which the worst-case cost is most sensitive. Numerical simulations and application to a hardware-in-the-loop servo-mechanism demonstrate the approach, with appreciable performance and robustness gains over alternative methods observed in both.
This article reviews Industry 4.0, its emerging phase, implementation, challenges, benefits, etc. It combines various fields where it has any influence and leaves some changes and where it requires some adaptation. Papers from the last 4 years are taken and analyzed, what is written about this topic in various countries with different backgrounds and economic development. Industry 4.0 affects the production environment by introducing new technologies which require a better-educated workforce so it affects education and requires some changes in curricula and ways of teaching. It brings new challenges and asks for a new approach from management to be able to handle fast and big changes in the business environment and to implement such innovation in production effectively.
The Editors' Network of the European Society of Cardiology (ESC) provides a dynamic forum for editorial discussions and endorses the recommendations of the International Committee of Medical Journal Editors (ICMJE) to improve the scientific quality of biomedical journals. Authorship confers credit and important academic rewards. Recently, however, the ICMJE emphasized that authorship also requires responsibility and accountability. These issues are now covered by the new (fourth) criterion for authorship. Authors should agree to be accountable and ensure that questions regarding the accuracy and integrity of the entire work will be appropriately addressed. This review discusses the implications of this paradigm shift on authorship requirements with the aim of increasing awareness on good scientific and editorial practices.
This paper proposes a control method for multi-input linear systems that provides the closed-loop system dynamics of an arbitrary order having a specified feasible spectrum of poles. By appropriate selection of auxiliary outputs, the system is decoupled into a set of subsystems. The number of these subsystems is equal to the number of control inputs. The desired dynamic of the considered system is achieved using higher order sliding mode, where the sliding mode of appropriate order is realized in each subsystem. The proposed control approach is illustrated by a simulation example.
The aim of this paper is to analyze if the Western Balkan and Eastern Partnership countries converge towards the twenty-eight members of the European Union. The relationships between the selected macroeconomic variables and per capita GDP growth rate are econometrically tested to support this research. The analyzed period is 2004–2017, with two sub-periods: 2004–2008 and 2009–2013. The subdivision is made to test whether the recent financial crisis affected the absolute and conditional convergence process in the analyzed group of countries. The empirical findings support the economic convergence hypothesis. The results show that the recent financial crisis negatively affected the absolute and conditional convergence process, when economic variables are included in the analysis. The negative effects of the crisis on conditional convergence with economic and socio-political variables are not identified. The poorer countries in the analyzed group should do more to attract investment and open their economies, as gross fixed capital formation and economic openness have a positive impact on per capita growth, and keep low inflation or stabilize it, while general government debt and unemployment should be decreased in the examined sample of countries.
Introduction: Venous thromboembolism (VTE) consists of two entities, deep venous thrombosis (DVT), and its complication, pulmonary embolism (PE). The main therapeutic goal is the prevention of this complication. Aim: The aim of the study was to present epidemiological data of patients with the diagnosis of deep venous thrombosis, with regard to the location of thrombosis, the value of fibrinogen and D-dimer in relation to the sex of the patients, the presentation of therapeutic modality, with the presentation of PE and treatment outcomes. Methods: The study has a retrospective and observational feature, covering the period from 2008 to 2017, and included 1154 patients with the diagnosis of deep venous thrombosis as a basic criterion for inclusion. Data on sex, age, diagnosis with thrombosis localization, hospitalization duration, administered therapy, D-dimer and fibrinogen values, pulmonary thromboembolism and mortality were collected. Results: The deep venous thrombosis was mostly located at the lower limbs - in 1079 respondents (93.5%), then at the upper limbs in 65 (5.63%) cases. The left side is more represented (58.9%) than the right (40.3%), which is statistically significant (χ2=40.03, p<0.005), while 0.9% of patients had DVT bilaterally. At the lower limbs is the most common iliac thrombosis, represented in 47% of thrombosis cases at the lower limbs. Subclavian axillary thrombosis has been reported in ¾ cases at the upper limbs. The mean fibrinogen concentration in all respondents is 5.2 mg/L, for men 5.0 mg/L and for women 5.3 mg/L, above the reference values (1.8-3.8 g/L). The mean value of D-dimer was 7.33 mg/L for all respondents, 8.46 mg/L for women and 6.5 mg/L for men, which was high above the reference limit (0.55 mg/L). From baseline, 88 (7.6%) of respondents had proven/high-grade pulmonary thromboembolism as a DVT complication in the observed period. Pearson correlation established a positive correlation between lethal outcome and patient age, r=0.13, p<0.005, followed by a higher incidence of lethal outcome after DVT in older patients. Conclusion: The incidence of venous thromboembolism is approximately equal among the genders, and increases with the age of the patients, especially in men. Fibrinogen and D-dimer values in hospitalized patients are higher than the reference, in both cases more among women. Multidisciplinary approach to patients, in cooperation with angiologists, pulmonologists, cardiologists and nuclear medicine specialists is an imperative. The development of a state-level registry that would follow the incidence of deep venous thrombosis, with reference to risk factors, is imperative and necessary in planning of community health system.
Introduction: Hypertension is significantly contributing to global mortality and morbidity and has been identified as the most important modifiable risk factor for early development of cardiovascular diseases (CVD). Aim: The aim of this study was to investigate the efficacy of different combinations of antihypertensive therapy on blood pressure, arterial stiffness and peripheral resistance in patients with essential hypertension using the brachial oscillometric ambulatory blood pressure monitor. Methods: This study was designed as an observational, prospective, multi centric study conducted in eight primary care centers of the Health Center of Canton Sarajevo during the period of six months. The study included 655 participants, both genders, aged between 30 and 75, who were diagnosed with hypertension according to the ESC/ESH guidelines. Participants were divided into six treatment groups based on the hypertensive drug therapy they were using; lisinopril, losartan or valsartan alone or in combination with hydrochlorothiazide (A, B and C group respectively) or combination of lisinopril, losartan or valsartan with/without hydrochlorothiazide together with amlodipine (D, E and F respectively). The participants were monitored at baseline, after 3 and 6 months (1st and 2nd follow-up). Brachial oscillometric ambulatory blood pressure monitor was used for measuring systolic (SBP), diastolic (DBP), pulse pressure (PP), pulse wave velocity (PWV) and peripheral resistance (PR). Results: SBP, DPB, PP, and PWV significantly decreased from baseline to 2nd follow-up in all treatment groups. The mean reductions in SBP were from -11.7 (95%CI; 9.3- 14.1) to -23.2 (95%CI; 18.3-28.1) mmHg and DBP reductions varied from -5.5 (95%CI; 3.9- 7.1) to -13.4 (95%CI; 7.7-19.1) mmHg. PWV decreased in all treatment groups (from -3.3% to -8.2%). Treatment regiment was not associated with significant differences in SBP, DBP, PP or PWV reductions or their values measured at 2nd follow-up. Peripheral resistance significantly decreased only in group C (p=0.011), group D (p=0.009) and group F (p=0.027). Conclusion: These data suggest that lisinopril/lisinopril + hydrochlorothiazide, losartan/losartan + hydrochlorothiazide and valsartan/valsartan + hydrochlorothiazide alone or in combination with amlodipine are equally effective and well tolerated for the reduction of both systolic and diastolic blood pressure and improve arterial stiffness in patients with essential hypertension.
Introduction: Breast augmentation is one of the most frequently performed aesthetic surgical procedures in the world. The most important preoperative decisions which influence the final appearance of the augmented breast are the breast implant pocket choice and selection of the most appropriate implant. Described pocket locations are subglandular, subfascial, partially retropectoral, totally submuscular and dual plane. Aim: We have introduced a new method of pocket forming for implant placement, which is combination of Tebbett’s dual-plane 2 or 3 and Graf’s subfascial. We named it as dual plane subfascial. Methods: Between January 2016 and April 2018, total of 27 patients were operated using dual plane subfascial breast augmentation. The pinch test in the medial pole less than 2,0 cm and in upper pole less than 2,5 cm are indications for this technique. In our modification, in primary cases a dissected flap in front of muscle is fasciocutaneous (not cutaneous as in Tebbett’s technique). It will be finally located caudally of pectoral muscle and in front of the lower pole of implant. Fasciocutaneous flap in primary cases and two independent levels of soft tissue coverage (fascial and cutaneous) in secondary cases (subglandular to dual plane subfascial conversion) in front of the lower pole of implants provide better coverage than cutaneous flap alone. Results: Hematoma and infection did not occur in any patient in our study. A capsular contracture grade I/II without the need for reoperation occurred in two patients. In one patient with secondary augmentation minimal bottoming out was noticed (before reoperation patient had significant bottoming out deformity). Minimal palpability of implants is recorded in three patients. Conclusion: Dual plane subfascial is a good option in primary breast augmentation with a well set indication especially in the breasts with the upper pinch test less than 25 mm and medial pinch test less than 20 mm. The idea can be followed even in secondary breast augmentation (subglandular to dual plane subfascial conversion). There is additional soft tissue in front of the implant which led to a less implant palpability, especially in thin patient with smaller amount of subcutaneous fat.
Objective The association between the neck circumference (NC) and components of metabolic syndrome in different countries and ethnic groups has been insufficiently investigated. The aim of the present study was to assess the impact of gender on NC values and to determine whether NC correlates with standard anthropometric measures and blood pressure values in Bosnian young adults. Materials and Methods Study participants were recruited by the snowball method. The NC, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured by trained personnel. Differences between the means were assessed by a Student's t-test. Coefficients of correlation were determined by Pearson's test. Results In young men (n=49), the value of NC was 37.71±1.79 cm, while in young women, (n=62) the value of NC was 32.23±1.83 cm (p<0.001). A significant positive correlation in both genders between the NC and BMI (r=0.70, p<0.001 in men; r=0.53,p<0.001 in women), and between the NC and WC (r=0.48, p<0.001 in men; r=0.38, p=0.01 in women), was found. A significant correlation between the NC and SBP (r=0.08, p=0.57), and DBP (r=0.20, p=0.17), in young men was not determined. Likewise, in young women, a significant correlation between the NC and SBP (r=0.08, p=0.54), and DBP (r=0.09, p=0.49), was not observed. Conclusion Our results suggest that the NC measurement can be used as a valid method in obesity assessment in young adults. A lack of association between the NC and blood pressure requires additional investigation.
This paper, on the basis of experimental research of the system in exploitation, identifies the main disadvantages of the existing troubleshooting scenarios for IPTV over xDSL. Also, this paper shows how the process of troubleshooting can be made more efficient in practice, with the already existing test solutions and other possibilities of test devices and xDSL transceivers.
Introduction: Noise represent an unwanted sound that endangers human health in multiple manners and in work setting causes reduction of productivity on one side, and increased waste on the other. Noise pollution occurs when the ear is exposed to the volume of sound that is disturbing, stressful or directly damaging hearing, but also acting on the organism as a whole. Aim: The aim of the article is to examine the vulnerability of workers working on the „press“ machine, and to carry out an analysis and examine the press operator workplace, then perform the noise spread measurement in the press operator work area and compare the current measurements with the permissible levels and analyze the time period of worker exposure, as well as presentation of the effects of noise on productivity and workers health. The aim of the article also includes the proposal for decrease of noise pollution. Methods: A noise analysis at the workplace of workers working on a „press“ machine was performed, which is exposed to a high impulse noise due to which the quality and quantity of production are reduced. For the purpose of calculating the noise level for one working day at the press operator site 1, 2 and 3, it is necessary to analyze the noise level in time. Operators spend most of their working hours at stations 1 and 3 where the measured noise level is Lm1 = 94.7 dB is taken, or at position 3, Lm3 = 97.2 dB. The measured noise level at these locations without the operation of the press is Lm1 = 80.1 dB, or at station 3 is Lm3 = 80.1 dB. Results: It was found that these operators working on the machine in question were exposed to a noise over the limit for more than three years. Their health problems that arise as a result of noise exposure are documented in their health charts. In order to achieve uninterrupted work at the press machine, during the eight hours shift, a noise correction is required to allow the equivalent sound level to fall within one day to the permissible 85 dB. In this regard, we consider the fact that we have known that the press produces a sound level of 110 dB, and that there is a reverberation (reflecting) sound. Given the technical characteristics of the plant, the reduction of the sound intensity of the source itself is not possible, so the suggestions of the technical solution will be based on reduced reflected sounds and to prevent the spread of direct sound to the operator. Conclusion: Workers are exposed to permanent noise during a working day, which produces a number of consequences for the health of the worker, but also the employer and the community. The imperative of the employer is to reduce the number of rejects, increase profitability and to have a positive impact on the health of the individual.
Rudolf Ludwig Carl Virchow (1821-1902) was a German doctor, anthropologist, pathologist, prehistorian, biologist, writer, editor, and politician, known for his advancement of public health (1-4). He is known as “the father of modern pathology” because his work helped to discredit humourism, bringing more science to medicine (1). He is also known as the founder of Social medicine and Veterinary pathology, and to his colleagues, the “Pope of medicine” (2).
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