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In this paper, we investigate the effects of in-phase/quadrature-phase imbalance (IQI) on the performance of different modulation schemes under multipath fading channels. In particular, a comprehensive framework for the analysis of coherent and noncoherent modulation with IQI is proposed. Specifically, new moment generating function (MGF) expressions for both point-to-point and multiple antenna systems are derived for the cases of transmitter IQI, receiver IQI, and joint transmitter/receiver IQI. Based on the derived MGFs, new analytical expressions for the corresponding symbol error rate (SER) are derived and are subsequently used to provide deep insights into the effects of IQI on the system performance. It is shown that, while in some cases the SER performance degradation due to IQI is marginal, in other cases, this impairment is more pronounced. Accordingly, IQI compensation is of paramount importance as it can guarantee a reliable communication link. This is particularly important in demanding communication technologies where reduction of latency and complexity are essential. publishedVersion

Traffic crashes are one of the most severe problems that affect communities worldwide. Despite that only 25% of all motor vehicle miles occur at night, about 50% of all traffic fatalities occur dur...

Wireless capsule endoscope (WCE) is a new diagnostic device that can be utilised for evaluating the whole digestive tract if effectively actuated. In this research, a new one degree of freedom (1DOF) actuation system based on a magnetic levitation concept is proposed for the capsule endoscope navigation system. The proposed system is used to move a permanent magnet inserted in WCE body by an arrangement of the current controlled electromagnetic actuator placed on a 3DOF movable frame. The aim of this study is to design a proportional–integral–derivative (PID) controller to suspend the capsule and keep it at a demand test region. DC and AC magnetic field-based positioning systems using the Hall effect sensor and the coil sensor, respectively are used to provide the controller by capsule position feedback. Improvement of the position feedback accuracy based on AC magnetic field using discrete Fourier transform is presented. Realistic simulation design of the system is implemented using Matlab/Simulink environment to validate the PID controller. The navigation scheme is implemented practically utilszing digital signal processor to verify the effectiveness of the controller. Finally, simulation and experimental results of the capsule navigation system are presented to show the performance of the proposed controller.

Precoding is proved to be highly efficient to improve the bit error rate (BER) of orthogonal frequency division multiplexing (OFDM) in frequency-selective fading channels. Nevertheless, most of the work reported in the literature ignores the radio frequency impairments such as carrier frequency offset (CFO), which is known to be of significant impact on OFDM. Consequently, this paper considers the performance evaluation of precoded OFDM (P-OFDM) in the presence of CFO. The performance of the considered P-OFDM is evaluated in terms of the signal-to-interference plus-noise-ratio (SINR) and BER. Various channel models are considered and closed-form analytical expressions are derived for the exact SINR. The obtained analytical results, corroborated by simulation, show that P-OFDM is substantially more sensitive to CFO compared with conventional OFDM. Generally speaking, if the normalized CFO is about 18%, then OFDM will outperform P-OFDM for most practical channel models. It is also interesting to note that the subcarriers in P-OFDM may experience different SINRs, which is not the case for conventional OFDM. The paper also considers the SINR of OFDM after the equalization process. The obtained results show that ignoring the impact of the equalization process results in inflated SINR degradation.

Selective mapping (SLM) and partial transmit sequence (PTS) are attractive schemes for mitigating the high peak power inherent in orthogonal frequency division multiplexing (OFDM) signals. However, the high computational complexity and redundant side information (SI) bits have been identified as the main limitations for such techniques. The high computational complexity is mainly due to the need to perform several inverse fast Fourier transforms (IFFTs), and phase optimization process at the transmitter side. Therefore, this paper presents new SLM and PTS designs using a low complexity T-transform rather than IFFT. The use of the T-transform with SLM achieves a considerable computational complexity and peak-to-average power ratio (PAPR) reduction. Furthermore, we apply the T-transform to PTS and derive two different configurations that compromise the SI requirements and PAPR reduction. All the proposed schemes do not affect the original power spectrum of OFDM signals. The complexity analysis show that the proposed schemes have much lower complexity as compared to conventional schemes. Moreover, simulation results demonstrate that the proposed schemes are resilient to dispersion arising from multipath propagation, which is due to the frequency diversity introduced by the T-transform.

In this work, we studied the tourist and recreational resources - relict, unique landscapes of the specially protected natural area of the Sharyn. The work is the result of many years of field research on landscapes and summer field practice in 2019 in the Sharyn River basin, the study and systematization of published scientific materials. 4 key sections were laid along 2 routes. On this basis, foci of landscape diversity were identified: relic tracts of Sarytugai with Sogdian ash (Fraxinus sogdiana Bunge), tracts Kurtogay, Moyyntugay and Temirlik with relict morphological sculptures. A digital thematic map was created on ArtGIS 10.1. The “passport” of the existing tourist routes and the “passport” of the recreational load of the protected areas Sharyn have been completed. To remove the anthropogenic load on the Sharyn Canyon, it was proposed to develop two more routes: "Small Canyon" and "Temirlik tract." The scientific base of the tourist and recreational potential has been created and the feasibility of further development of international tourism has been substantiated.

Background: An injury to both the primary and permanent teeth and the supporting structures is one of the most common dental problems seen in children. Splinting is usually difficult or impossible to perform in the primary dentition (due to diminutive room size and lack of patient cooperation). Healing must, therefore, occur despite mobility at the fracture line, usually resulting in interposition of connective tissue. In some instances, infection will occur in the coronal pulp. The present study reported a case of trauma to the anterior primary teeth and alveolar bone in a four year old child. The trauma has caused fracture to the crowns and roots of the primary anterior teeth. The following case was managed in a procedure that may provide primary teeth subjected to trauma a better chance than extraction with a better prognosis. Case presentation: a 4 and a half year old child was subjected to trauma in anterior segment of maxilla. Suturing of the torn soft tissue was the first step followed by pulpotomy for the left primary lateral incisor. Fixation of the right primary central and lateral incisors was done by acid etch wire fixation. Both clinical and radiographic follow up was carried out for 6.4 years. Results: healing of the soft tissue was observed after one week and completed after two months. Fixation of the teeth continued for ten months. The fracture lines in the roots remained in position. Clinically there was no sign of any pulpal inflammation or necrosis. Radiographically, no signs of infection to the surrounding tissues could be seen, no resorption in the alveolar bone, external or internal resorption of the root did not happen also. After ten months fixation ended and the wire was removed. At that time there was normal resorption of the roots of the primary incisors in relation with the normal development of the permanent incisors. After 3 years both permanent central incisors erupted in their normal position. After 6.4 years all four permanent incisors erupted into occlusion in their normal position. Conclusion: primary teeth with root fractures and severely mobile coronal fragments can be treated by a conservative approach. The severity of the sequels is directly related to the degree of permanent tooth formation (child’s age), type of dental trauma and extent of the impact. Key words: trauma, primary incisors, fractured crown and root

This paper considers the bit loading problem for communication systems that utilize orthogonal frequency division multiplexing (OFDM) in conjunction with precoding (POFDM) or time-domain interleaving (IOFDM). In particular, we propose a new bit loading algorithm for P/I-OFDM that has substantially higher effective throughput and less computational complexity, when compared to bit loading in conventional OFDM systems. The obtained results show that the effective throughput of P/I-OFDM can be more than fourfold the conventional OFDM while the complexity is less than $1.5\%$ . Moreover, the results show that the peak-to-average power ratio (PAPR) properties of the considered systems are preserved under the adaptation process.

The explosive growth of connected devices poses key challenges on the effective design and deployment of future wireless systems and networks. Nonorthogonal multiple access (NOMA) has been recently proposed as a viable solution to such related challenges because it has been shown to be capable of enabling increased spectral efficiency, massive connectivity, and low latency. NOMA allows multiple users to share the same frequency bands and time slots through power-domain or code-domain multiplexing, while successive interference cancelation (SIC) eliminates the resulting multiuser interference. However, transceiver architectures inevitably suffer from radio-frequency (RF) front-end-associated impairments, such as in-phase (I)/quadrature-phase (Q) imbalances, dc offsets, and power amplifier (PA) nonlinearities. This article addresses the main RF impairments that degrade the performance of communication systems in the context of NOMA-based communication scenarios. In addition, it provides useful insights into the potential opportunities and challenges that are envisioned to enable efficient design and implementation of NOMA in future wireless networks. Extensive computer simulations assuming such impairments reveal that NOMA communication systems experience significant performance degradation compared to conventional orthogonal multiple access (OMA) schemes. Furthermore, the different users in NOMA inevitably experience different levels of degradation, which highlights the importance for accurate modeling and dynamic compensation of the incurred impairments to ensure successful deployment of NOMA in critical applications, such as vehicle-to-vehicle communications.

Background: Trauma to the anterior teeth is a common injury in young children. Themaxillary incisors being the most affected. Although root fractures are rare, theydo occur and were previously and often considered hopeless and were extracted.The time between the injury and the initiation of treatment, level of the fractureline, and stage of root development are some criteria to be considered whenchoosing a treatment approach for a complicated tooth fracture. This case reportdescribes the management of a traumatized immature maxillary central incisorwith Elise class IV fracture with vertical oblique subgingival fracture of the root.Materials and method: Apexification was carried out using biodentine followed byremoval of the fractured segment. A fiber post was cemented in the root canalwith resin cement. The coronal portion of the tooth was restored using anteriorlight cured composite material. The tooth was examined and evaluated after 1week and after 2 months by clinical examination and radiographical evaluation ofroot development.Results: The follow up evaluation revealed clinical and radiographical success.Radiographic view showed continued development in the apex of the root andshowed normal periodontal ligament space and dense lamina dura.Conclusion: Extraction should not be the first choice of treatment for extensivelydamaged young permanent teeth in the anterior region; instead, alternativetreatment modalities must be considered. The traumatized immature tooth wassaved and restored.

This study aimed to investigate the mechanical and electrochemical properties of concrete that uses recycled brick aggregate (RBA) as a substitute for natural coarse aggregate (NCA). The study focusses on the workability, compressive strength and the electrical resistivity of concrete made with RBA. To test the effects of incorporating RBA on the properties of concrete, 6 different mixes were made with increasing incorporation percentages (0%, 20%, 40%, 60%, 80%, 100%). It was found that the negative effect of RBA on the workability of concrete can be negated using additives such as plasticizers. The study also showed that the compressive strength of concrete was reduced from 54 MPa for control specimens to 30 MPa at 100% replacement of RBA (44% reduction). No significant reduction in strength was observed in RBA replacement range between 60 to 100%. Additionally, the study showed that a harsh environment with high chlorideion concentration has no negative impact on the compressive strength of concrete. Finally, the results of the electrical resistivity (ER) test showed that higher RBA% tend to decrease the ER of concrete both immediately and over-time. Overall, the decrease in electrical resistivity resulting from the usage of RBA in the concrete puts the steel reinforcement at high risk of corrosion; therefore, protective measures must be employed when using RBA under severe exterior exposure.

Background: The most common reason for re-making a maxillofacial prosthesis is the degradation of the mechanical properties of the silicone.Aim of this study: To assess some mechanical properties of VST-50F maxillofacial silicone reinforced with a composite of silicon dioxide nanoparticle and polyamide-6 microparticle before and after artificial aging.Material and Method: Preparing 240 samples tested for tear strength, tensile strength and elongation percentage, hardness, and roughness before and after aging. The Silicon dioxide was added in concentrations of 1% by weight and Polyamide-6 in the concentration of 0.25% and 0.5% by weight to the VST-50F RTV maxillofacial silicone. The one-way ANOVA and post hoc tests were used for inferential statistics.Results: The one-way ANOVA showed a highly significant difference between all tested groups. The effect of the addition of composite fillers showed an increase in tear strength, hardness, and surface roughness but a decrease in tensile and percentage of elongation. However, the effect of artificial aging showed increased in tear strength, Percentage of elongation, and surface roughness, but a decrease in tensile strength and hardness.Conclusion: Addition of composite of fillers into the silicone elastomer allowed enhancement of some mechanical properties. The composite of different types of filler reinforcement improves the anti-aging properties of silicone and maintain some of the mechanical properties to enhance the service life.

الملخص: أهداف البحث: للحصول على تصورات الأطباء عن خبراتهم ووعيهم حول الأحكام المؤسسية التي يمكن أن تعزز مشاركة المريض في المملكة العربية السعودية. طرق البحث: في إبريل٢٠١٧، تم عمل استطلاع عبر الإنترنت عن طريق توزيع استبانة عبر نموذج مستند جوجل للأطباء في المملكة العربية السعودية. يحتوي المستند أسئلة حول خبرة ووعي الأطباء للأحكام المؤسسية من الموارد والدعم. النتائج: استجاب للاستطلاع ٣٢٥ طبيبا. وأوضحت النتائج أن ١٨.٥٪ منهم يرون أن مؤسساتهم تسمح بجدولة المواعيد عن طريق الإنترنت، و٨.٩٪ تسمح بالتواصل بين المرضى والأطباء عبر البريد الإلكتروني، و٢٤٪ تسمح لوصول المرضى للسجلات الصحية ونتائج التحاليل عبر الإنترنت، و٥٥.٧٪ تسمح بتوفير البرامج التعليمية متعددة الوسائط، و٧٤.٨٪ تسمح بصنع القرار-المشترك بين الأطباء والمرضى. كما ذكر ٣٤.٥٪ فقط من المستجيبين أن مؤسساتهم تقوم بتوفير زيارات منزلية للمرضى ذوي الخطورة العالية. يرى ستة من ١٠ مستجيبين أن هذه الأحكام سيكون لها تأثير إيجابي ونتيجة لهم وأيضا لمرضاهم. الاستنتاجات: يعي الأطباء ويقيمون الأحكام التي تعزز مشاركة المريض. ولكن العديد من المؤسسات لا تدعم وتمارس هذه الأحكام التي تعزز مشاركة المريض. الأطباء الذكور ذوي الخبرة الأطول من الممارسة وأولئك الذين يشغلون مناصب إدارية عليا هم أكثر من يقدم الدعم، ويقدر أهمية تعزيز مشاركة المريض في ممارستهم. Abstract: Objectives: To survey physicians' perceptions of their experience and awareness of institutional provisions that can potentially foster patient engagement (PE) in KSA. Methods: In April 2017, an online survey was distributed to clinicians in KSA using Google Forms. The instrument contained questions about the physicians' awareness and experience of their institutions' provision of resources and support. Results: Three hundred and twenty-five clinicians responded to the survey The results showed that 18.5% claimed that their institutions allowed online scheduling of appointments; 8.9% reported the institutions permitted contact between patients and physicians through email; 24.0% reported they provided patients with online access to health records and test results; 55.7% claimed they provided educational multimedia programming; and 74.8% confirmed they encouraged joint decision-making between physicians and patients. Only 34.5% of respondents claimed their institutions provided home visits for high-risk patients. Six of 10 respondents thought that such provisions would have positive outcomes for them and for their patients. Conclusions: Clinicians are aware of and value provisions that foster PE. However, several institutions in KSA do not support or have provisions in place to foster PE. Male clinicians with longer durations of practice and those with higher administrative positions are more likely to value the importance of PE and support and use it in their practice. الكلمات المفتاحية: إشراك, المؤسسية, المريض, الأحكام, الدعم, Keywords: Foster, Institutional provision, Patient engagement

The proliferation of mobile Internet and connected devices, offering a variety of services at different levels of performance, represents a major challenge for the fifth generation wireless networks and beyond. This requires a paradigm shift towards the development of key enabling techniques for the next generation wireless networks. In this respect, visible light communication (VLC) has recently emerged as a new communication paradigm that is capable of providing ubiquitous connectivity by complementing radio frequency communications. One of the main challenges of VLC systems, however, is the low modulation bandwidth of the light-emitting-diodes, which is in the megahertz range. This article presents a promising technology, referred to as "optical- non-orthogonal multiple access (O-NOMA)", which is envisioned to address the key challenges in the next generation of wireless networks. We provide a detailed overview and analysis of the state-of-the-art integration of O-NOMA in VLC networks. Furthermore, we provide insights on the potential opportunities and challenges as well as some open research problems that are envisioned to pave the way for the future design and implementation of O-NOMA in VLC systems.

To make concrete a truly green material, viable cement substitutes are available. This experimental investigation is performed to study the effect of using limestone powder (LSP) and styrene butadiene rubber (SBR) latex in the concrete mix. In this work, a concrete with 1:1.8:3 cementitious material:sand:gravel and water/cement ratio w/c of 0.5 is produced. First, LSP is used with 0, 5, 10, 15, and 20% replacements by weight of cements. The fineness of the LSP is measured using sieve No. 200 and showed about 30% pass. Second, and to improve the matrix of concrete due to the dilution effect, four ratios of SBR latex (0, 5, 10, and 15%) are added by weight of cements to the mix for each LSP ratio. Compressive strength at ages of 3, 7, 14, 28, and 90 days is tested for the concrete specimens mixed with LSP only to examine its effect on concrete strength’s development with time, whereas strengths are recorded at the age of 28 days for the other concretes. Three prisms were cast for each ratio and tested at 28 days. The results show general improvements in terms of compressive and flexural strengths.

This study was design to investigate the dimensional stability of heat-activated acrylic resin with different methods of flask cooling (15 minutes rapid cooling, one hour bench cooling, four hours delayed deflasking, and 24 hours delayed deflasking) at different time intervals (immediately, two days, seven days, 30 days) after deflasking.Heat-activated acrylic resin was used to prepare acrylic samples. Then, measurement of the distances where achieved between the centers of selected marks in the acrylic samples. They were measured at different time intervals for different methods of flask cooling.The results showed that the group samples of the four hours and 24 hours of delayed deflasking was insignificantly different from the control and followed by the group of one hour bench cooling. The quenched group was significantly different from the control group.The heat-activated acrylic resin should be kept in the flask for four hours or more after processing to achieve more accurate dentures.

Aim of the study: The aim of this study was to introduce ear lobes as alternative landmarks for the interpupillary line during orientation of the occlusal plane. Also, the other aim was to compare the ear lobes with the pupils of the eyes to verify that they were indifferent as anatomical landmarks.Method: The alternative landmarks, ear lobes, were presented and the method for orienting the occlusal plane with these landmarks was introduced. Digital pictures of 30 subjects, who participated in the study, were analyzed to compare the parallelism of the interpupillary line with the ear lobes.Results: The results of this study showed that the interpupillary line was parallel with the line drawn between both ear lobes for the same subject.Conclusion: The ear lobes were reliable and dependable alternative landmarks for the orientation of the occlusal plane and could be used with less effort than that of the conventional method utilizing the interpupillary line.

Non-orthogonal multiple access (NOMA) has been recently proposed as a viable technology that can potentially improve the spectral efficiency of fifth generation wireless networks and beyond. However, in practical communication scenarios, transceiver architectures inevitably suffer from radio-frequency (RF) front-end related impairments that can lead to degradation of the overall system performance with in-phase/quadrature-phase imbalance (IQI) constituting a major impairment in direct-conversion transceivers. In this paper, we quantify the effects of IQI on the performance of NOMA-based single-carrier (SC) and multi-carrier (MC) systems under multipath fading conditions. This is realized by first deriving analytic expressions for the signal-to-interference-plus-noise ratio and the outage probability of both SC and MC NOMA systems subject to IQI at the transmitter and/or receiver (RX) side. Furthermore, we derive asymptotic diversity orders for all considered impairment scenarios. Capitalizing on these results, we demonstrate that the effects of IQI differ considerably among NOMA users and depend on the underlying systems’ parameters. For example, for a target data rate and power allocation ratio satisfying a given condition, IQI does not affect the asymptotic diversity of SC NOMA systems, whereas the asymptotic diversity of MC NOMA systems, suffering from RX IQI, is always zero. Moreover, it is shown that for both SC and MC NOMA systems, the first sorted user appears more robust to IQI, which indicates that higher order users are more sensitive to the considered impairment.