Search

Virtually all epistemologists agree that truth is a necessary condition for knowledge. Assuming that our three-dimensional world is nested within a higher-dimensional space, I use multidimensional geometry to present a type of case which undermines this fundamental principle of epistemology. I further argue that we would be unlikely to revise our epistemic practices in light of new discoveries even if our world turned out to be substantially different and many of our beliefs turned out to be false.

One common problem with anti-skepticism and skepticism alike is their failure to account for our sometimes conflicting epistemic intuitions. In order to address this problem and provide a new direction for solving the skeptical puzzle, I consider a modified version of the puzzle that is based on knowledge claims about appearances and does not result in a paradox. I conclude that combining the elements of both the original and modified puzzle can potentially guide us towards solutions that can fully explain the conflict of epistemic intuitions.

Autonomous vehicles are expected to take complete control of the driving process, enabling the former drivers to act as passengers only. This could lead to increased sickness as they can be engaged in tasks other than driving. Adopting different sickness mitigation techniques gives us unique types of motion sickness in autonomous vehicles to be studied. In this paper, we report on a study where we explored the possibilities of assessing motion sickness with electrogastrography (EGG), a non-invasive method used to measure the myoelectric activity of the stomach, and its potential usage in autonomous vehicles (AVs). The study was conducted in a high-fidelity driving simulator with a virtual reality (VR) headset. There separate EGG measurements were performed: before, during and after the driving AV simulation video in VR. During the driving, the participants encountered two driving environments: a straight and less dynamic highway road and a highly dynamic and curvy countryside road. The EGG signal was recorded with a proprietary 3-channel recording device and Ag/AgCl cutaneous electrodes. In addition, participants were asked to signalize whenever they felt uncomfortable and nauseated by pressing a special button. After the drive they completed also the Simulator Sickness Questionnaire (SSQ) and reported on their overall subjective perception of sickness symptoms. The EGG results showed a significant increase of the dominant frequency (DF) and the percentage of the high power spectrum density (FSD) as well as a significant decrease of the power spectrum density Crest factor (CF) during the AV simulation. The vast majority of participants reported nausea during more dynamic conditions, accompanied by an increase in the amplitude and the RMS value of EGG. Reported nausea occurred simultaneously with the increase in EGG amplitude. Based on the results, we conclude that EGG could be used for assessment of motion sickness in autonomous vehicles. DF, CF and FSD can be used as overall sickness indicators, while the relative increase in amplitude of EGG signal and duration of that increase can be used as short-term sickness indicators where the driving environment may affect the driver.

We present a combination of fractional order calculus and Savitzky-Golay filter for extraction of both electrogastrogram and pulse rate signal from a mixed signal recorded with high sampling frequency (1 kHz). In order to evaluate the proposed method, we generated semi-synthetic biosignal mixture. In order to assess proposed methods, signal-to-noise ratio was calculated for the resulting extracted signals. Obtained results suggest that there are benefits from the combination of Savitzky-Golay filter and fractional order calculus, compared to the application of separate individual application of those methods. Further examination will be performed on in vivo recorded signals.

The skeptical puzzle consists of three allegedly incompatible claims: S knows that O, S doesn’t know that ~U, and the claim that knowledge is closed under the known entailment. I consider several famous instances of the puzzle and conclude that in all of those cases the presupposition that O entails ~U is false. I also consider two possible ways for trying to make it true and argue that both strategies ultimate fail. I conclude that this result at least completely discredits any solution that denies the principle of epistemic closure. At most, denying that O entails ~U can itself be seen as a novel solution to the puzzle, preferred to any other solution: it accommodates both non-skeptical and skeptical intuitions but does not require us to give up the principle of closure, embrace contextualism or subject-sensitive invariantism, or deny any commonly accepted principle of epistemology or logic.

Surface electrogastrography (EGG) is a non-invasive technique that is used to record myoelectrical activity of the stomach using cutaneous electrodes placed on the abdomen. Gastric motility assessment by EGG is a candidate for standard clinical procedure based on the quantification of parameters characteristic of gastric motility disorders. Despite its noticeable benefits, EGG is not widely implemented in clinical practice. The main reasons are: (1) lack of standardization of electrode placement, (2) time-consuming diagnostic procedures and (3) a complex multi-channel recording setup. We proposed a methodology in which an easy-to-use single-channel EGG, with a less time-consuming protocol (−6). We showed that a less time-consuming recording session with light meal intake could be used for the assessment of gastric myoelectrical activity (GMA).

In the era of technological advances and innovations in transportation technologies, application of driving simulators for the investigation and assessment of the driving process provides a safe and suitable testing environment. Although driving simulators are crucial for further improvements in transportation, it is important to resolve one of their main disadvantages&ndash, simulator sickness. Therefore, suitable methods for the assessment of simulator sickness are required. The main aim of this paper was to present a non-invasive method for assessing simulator sickness by recording gastric myoelectrical activity&ndash, electrogastrography. Open-source hardware for electrogastrography together with recordings obtained in 13 healthy volunteers is presented, and the main aspects of signal processing for artifact cancellation and feature extraction were discussed. Based on the obtained results, it was concluded that slow-wave electrical gastric activity can be recorded during driving simulation by following adequate recommendations and that proposed features could be beneficial in describing non-ordinary electrogastrography signals.

The aim of this study was to investigate possible correlation of specific skeletal or dental class in children and adolescents with clinical signs of temporomandibular dysfunction (TMD) with the severity of internal derangement (ID) of the temporomandibular joint.Based on MRI images, the ID of 232 juvenile temporomandibular joints in 116 patients were retrospectively recorded. The distribution of the ID stages within the skeletal and dental classes was compared by means of the χExcluding the comparison between skeletal Class I (S I) and skeletal Class II (S II; p 0.05), no statistically significant differences in the distribution of the ID stages were found between the skeletal classes (p 0.05). No statistically significant differences were found when comparing the distribution of the ID stages between the dental classes (p 0.05).According to these findings, there is no skeletal or dental class that is related to higher degrees of internal derangement in the TMJs of children and adolescents presenting clinical signs of TMD. Therefore, it is not possible to draw conclusions about the severity of the ID in relation to the dental and skeletal class in symptomatic juvenile TMJs.

The comparison of two methods used to separate electrocardiography and electromyography signals: Empirical Mode Decomposition (EMD) and Fractional Order Calculus (FC) is presented. For quantitative evaluation, crest factor (CF) and signal-to-noise ratio (SNR) values were calculated, where higher CF and SNR values were preferable. Results suggest that FC and EMD performance can be partially assessed by CF indicating better artifact cancellation with EMD approach by 9.72%. For FC and EMD, automatic fractional order application and intrinsic mode function selection were suggested and discussed, respectively. In summary, the results suggested that proposed filtering assessment should be enhanced for more appropriate FC and EMD method's assessment.

The paper presents the computer simulation and the measurement results of the realized strip horn antenna intended for operation at 9–15 GHz range. The antenna is fabricated with 20 mm wide and 1 mm thick aluminum strips. The arms of the horn are 60 mm long while the aperture angle is 60. The excitation is performed through the SMA connector pin which is placed at the quarter wavelength distance from the short-circuited strip.

Numerous studies have been devoted to the causes of craniomandibular dysfunction (CMD). This investigation addressed the effect of class III malocclusion and crossbite on CMD based on a sample of 115 prepubertal and adolescent patients of both sexes. Although class III malocclusion only accounted for 12.2% of the total sample, thus, being the smallest group, the percentage of crossbite (71.4%) among these patients was disproportionately higher than among the other classes. Of the total sample, the prevalence of crossbite was 30.4%. We compared these findings to a large-scale (n=4727) study by Thilander et al. (2002), who reported a strikingly high percentage of class I patients compared to our findings (72.7% versus 27.8%) and a lower percentage of crossbite cases (8.0% versus 30.4%). In accordance with the "orthodontic risk child" concept by Grabowski et al. (2007) and Stahl et al. (2007), we conclude that class III malocclusion and crossbite are keys in the pathogenesis of CMD.

The aim of this paper is to emphasize the necessity of reindustrialization of the Serbian economy. In order to ensure the preservation of the economy in terms of substantially altered external environment, first of all, it is necessary to consolidate the existing state and to ensure the growth of industrial production. This can be achieved by focusing resources primarily on the following industries: petrochemical, agro-industry, automotive industry, textile industry, and building materials industry. However, to ensure long-term sustainability of the Serbian economy, as soon as an acceptable level of growth in industrial production is reached, it will be necessary to enter the next phase - development of the Serbian industry based on knowledge and modern technologies.

Some growth models mark energy consumption as the cause, while others mark it as a consequence of economic growth. Empirical research serve as the grounds to determine these relationships in the conditions of modern energy resource market in the countries characterized by different levels of development and energy intensity. Our goal in this work is to use the hypotheses of various growth models and the findings of different empirical research in defining the role of energy supply in the post-crisis model of development in Serbia. The role of energy will be analyzed in terms of both the responsibility of the policy makers in the field of ensuring the energy security of the country and the investments as one of the economic growth drivers.

The present case report documents the hitherto unusual application of camouflage orthodontics in one of our patients. Our female patient had previously been treated orthodontically alio loco and had also undergone bimaxillary orthognathic surgery. She presented with TMJ complaints, with associated pains. Despite a dental Class I and centrally seated condyles, her discs had prolapsed anteriorly without reduction and she had developed a massive degenerative-inflammatory TMJ disease. Skeletally, she was a Class II case despite previous orthognathic surgery. In addition, there was also an initial suspicion of rheumatic involvement that could not be confirmed. We distalized the entire lower dental arch without bicuspid extraction. Then we advanced the mandible with the Mandibular Anterior Repositioning Appliance (MARA).We discuss exactly how the modified camouflage therapy was structured and how the individual treatment steps took place.

Occasionally, undesirable post-surgical symptoms of temporomandibular disorder (TMD) and pain have been observed. The aim of this paper is to show how often and to which degree TMJ pathologies occur in orthognathic surgery candidates before surgery, making it recommendable to consider these TMJ pathologies during treatment planning. Between 2002 and 2004, Magnetic Resonance Imaging (MRI) of the TMJ were made in 58 randomly chosen orthognathic surgery patients. 69% of the patients were female, 31% were male. Age averaged 31.6 years (16–61 years). Gender and malocclusion (Class I, II and III) were looked at during analysis of the data (n = 58 patients, n = 116 TMJs). MRI scans were made at the beginning of treatment. We wanted to investigate the TMJ condition before surgery. The largest patients group of this study were the female Class II patients (n = 25). Most patients displayed an Angle Class II (53.4%). The Class III patients followed (32.8%). A Class I molar relationship was found in 13.8% of the studied patients. A similar distribution could be observed in the parameters we studied: 1. condyle (position, degeneration), 2. disc (position, degeneration, prolapse and reduction). 76% of the TMJs (66.7%) showed dorsocranial condylar displacement. 26 of the 114 studied condyles (22.8%) were dorsally displaced. 108 of the studied joints (94.7%) showed condylar displacement. In 31 TMJs (28,4%) we found moderate, in 25 joints (22.9%) severe and in 26 joints (23.9%) we observed slight condylar degeneration. Most discs were displaced ventrally (31%). 22 of the studied 113 discs (19.5%) were displaced medially. 93% of the studied discs were not positioned correctly. 58 of the studied discs (58.6%) displayed flattening, in 8 (8%) we observed both flattening and disc adhesions. Two each of the studied TMJs had discs with perforations and adhesions or only perforations. In 57 (50.4%) of the studied discs we observed partial disc prolapse. Disc prolapse was total in 42.5% (n = 48 TMJs) of the TMJs. Eight TMJs (7%) of the 113 TMJs we analyzed showed no disc prolapse. Disc reduction was total in 71 (62.8%) of the studied TMJs. 15% (n = 17 TMJs) showed a partially reduced disc. 25 (22.1%) of the studied joints showed no disc reduction. Apparently, MRI scans of the TMJ are necessary in almost all potential orthognathic surgery patients to achieve optimal surgical results. Female Class II patients recruited the largest patient group among the studied collective. It is this group that deserves the greatest caution before and after surgery (TMJ pathologies!). In patients with jaw discrepancies, a TMJ examination should be made prior to surgery in order to be able to include the condition of the TMJs in the planning of treatment. This examination best includes Magnetic Resonance Imaging (MRI) and Manual Functional Analysis (MFA).

This paper presents electromagnetic simulation software package WIPL-D microwave and design, passive PIN diode limiter for higher RF power in combination of waveguide and print techniques. The Limiter is designed for use at X-range of protection low noise semiconductor amplifiers and includes two spatially separated PIN diodes.

The paper investigates how a pragmatics-based approach may influence Concurrent Engineering (CE) implementation projects. Pragmatics, a field of semiotics, is used as a perspective for analyzing, as an instrument for constructing manufacturing systems and, in this particular research, as an instrument for CE implementation projects. In particular, as a part of the CE implementation methodology, modeling and the effects of different interpretations (as pragmatics aspects) of the assessment of processes’ simultaneity in a manufacturing organization are studied. The underlying thesis is that different interpretations significantly influence the perception of the organization’s reality, which has an impact on the project’s success. As a representation class, the so-called Simultaneity (Concurrency) Matrix (SCM) was used for simultaneity process assessment. The thesis is validated in two manufacturing companies. The results suggest that further improvements of the CE implementation methodologies, when using the pragmatics-based approach, lead to better quality of decisions and provide some assurance for the success of short-time and low-cost CE implementation projects.

Frequently, Angle Class IIs display a retrognathic mandible rather than a prognathic maxilla [McNamara, Connelly & McBride, 19751]. Since the mandible appears to be the primary cause, it is logical to focus on it when treatment options are discussed. Consequently, all major fixed and removable Class II correction appliances attempt to improve mandibular growth and position. Several types are available on the market: Fixed Functionals like the MARA (Mandibular Anterior Repositioning Appliance), the Herbst appliance and William Clark’s Twin Block are, however, by far, more effective than removable appliances in more difficult cases and in cases with lacking or insufficient patient compliance. [O’Brien, Wright, Conboy et al., 20032] The primary difference between Class II/1 and Class II/2 is the angle of upper incisor inclination: In Class II/1s, the upper anteriors are proclined, creating a large sagittal step with the lingual, gingival part of the upper incisors holding the mandible posteriorly. This often causes enormous pressure on the TMJs and thus damage to the structures of the TMJ. In Class II/2s, the bite is usually very deep, and the upper incisors are retroclined, also producing a force vector that is directed distally, toward the TMJs. The bite in Class II/2s is not seldomly extremely deep, and the vertical height of the lower face is often reduced (brachycephalic growth). A great help for optimal diagnostics and treatment planning in orthodontic patients, esp. in patients with TMD (Temporomandibular Disorder) symptoms, has been MRI (Magnetic Resonance Imaging). MFA (Manual Functional Analysis) has recently evolved in the Netherlands and Germany as an important complement to MRI scanning. It covers very well the functional aspects of TMD, because it is a thorough orthopaedic type of musculoskeletal examination. Although dynamic imaging has been developed to diagnose mandibular mobility and disc behaviour, the MFA is also still a valuable adjunct as a diagnostic tool. Combining the very important MRI with MFA, the clinician gains very important knowledge of the condition of the TMJs and if the condyles can be advanced or not. MRI scanning and MFA also are the decisive factors as to the type of manual therapy / physiotherapy that is indicated as complement to mechanical anterior mandibular advancement. The latter is crucial, because without proper manual therapy -, it is much more difficult or even impossible to obtain satisfactory and stable treatment results.

The paper presents simulated and measured results of the UHF RFID antenna realized with dipole matched to a CPS (coplanar stripline) and inductively coupled with small rectangular loop. Such design of the antenna enables easy achieving and controlling high values of the inductive reactance that is necessary for obtaining good matching of antenna to ASIC (Application Specific Integrated Circuit) chip. The antenna is characterized by simple and robust design which results in low-cost realization.

Aim: To draw attention to this relatively common disease, which may cause major visual function impairment, and to present our own experience in the diagnosis, treatment and follow-up of acute retinal necrosis patients. Methods: The manifestation, detection, treatment options and complications of unilateral acute retinal necrosis are illustrated by six case reports. Results: Five patients were immunocompetent, whereas the sixth one suffered from chronic leukemia. In two patients the disease developed in association with herpes zoster, whereas the remaining four showed no signs of herpes disease. Systemic therapy with acyclovir, corticosteroids, salicylates and photocoagulation produced favorable response in five patients. Therapy had to be discontinued in leukemia patient for complications, which resulted in the disease recurrence with retinal detachment and proliferative vitreoretinopathy. Other patients remained stable with preserved visual function and only minor complications. Discussion: In all six patients, the accurate diagnosis was reached relatively late. Obviously, anterior uveitis alone attracted ophthalmologists' attention, and their diagnostic and therapeutic efforts had mostly been focused on anterior uveitis impairment in the visual acuity developed. Appropriate therapy with virostatics, which is necessary in the treatment of this disease, was introduced relatively late, however, all patients responded favorably to this therapy, which also held for the immunocompromised patients administered a half usual dose of acyclovir. Our experience confirmed that virostatic therapy for acute retinal necrosis should be administered for at least 6 weeks. Retinal photocoagulation for prevention of rhegmatogenous retinal detachment appers to be beneficial, as this type of retinal detachment did not develop in these patients. The patient who did not undergo laser photocoagulation of retina did not develop rhegmatogenous retinal detachment but did develop proliferative vitreoretinopathy. Conclusion: Acute retinal necrosis is a relatively common disease affecting visual function, which occurs in both immunocompetent and immunocompromised subjects. The disease with its typical clinical picture and many complications should be taken in consideration on the differential diagnosis of uveitis. Therapy for acute retinal necrosis is complex, long-term and associated with frequent systemic complications that may threaten the patient's general health status.

This paper presents simulated (WIPL-D pro) and measured results of a UHF RFID antenna realized with a dipole matched to a CPS (Coplanar Stripline) and inductively coupled with a small rectangular loop. Such a design enables achieving and controlling high values of the inductive reactance that is necessary for obtaining good match of the antenna to an Application Specific Integrated Circuit (ASIC) chip. The antenna is characterized by a simple and robust design, which results in low-cost realization.