Scalable Group Secret Key Generation over Wireless Channels

In this paper, we consider the problem of secret key generation for multiple parties. Multi-user networks usually require a trusted party to efficiently distribute keys to the legitimate users and this process is a weakness against eavesdroppers. With the help of the physical layer security techniques, users can securely decide on a secret key without a trusted party by exploiting the unique properties of the channel. In this context, we develop a physical layer group key generation scheme that is also based on the ideas of the analog function computation studies. We firstly consider the key generation as a function to be computed over the wireless channel and propose two novel methods depending on the users transmission capability (i.e. half-duplex and full-duplex transmissions). Secondly, we exploit the uniqueness of the prime integers in order to enable the simultaneous transmission of the users for key generation. As a result, our approach contributes to the scalability of the existing physical layer key generation algorithms since all users transmit simultaneously rather than using pairwise communications. We prove that our half-duplex network model reduces the required number of communications for group key generation down to a linear scale. Furthermore, the full-duplex network model reduces to a constant scale.Comment: 7 pages, 3 figure, transaction

Prevalence of carpal tunnel syndrome in cases with migraine and tension type headache

Background: Carpal Tunnel Syndrome (CTS) is the most frequent entrapment neuropathy; also Tension Type Headache (TTH) and migraine headache are the most common forms of headaches. The aim of this study is to determine whether there is a relationship between carpal tunnel syndrome and migraine and/or TTH, and if so, to determine the factors causing this relationship.  Methods: This study included 201 patients who were electro-physiologically diagnosed with idiopathic CTS and 100 controls. In addition to being examined for headaches, each patient’s Body Mass Index (BMI) was determined, and each was evaluated with Boston Questionnaire Form (BQF) and a Beck Depression Scale (BDS).  Results: The CTS group had significantly more patients with TTH and migraine headache than did the control group. In addition, the CTS group had a significantly higher frequency of headaches, and significantly higher BDS and BMI than did the controls. There were no significant differences in headache type and frequency of headache between those with mild CTS and those with mild-serious CTS. In addition, the Boston scores of CTS patients with headache were higher than those CTS patients without headache. Further, the monthly income levels of patients with CTS were lower than those of the control group.Conclusion: We found that primary headache is more frequent in CTS patients than in controls. This may be due to somato-autonomic reflexes and other common risk factors that can be seen in both CTS patients and those with headache, including obesity, depression and low level of income.

The investigation of association between IL-1Ra and ACE I/D polymorphisms in carpal tunnel syndrome

WOS: 000423046100052PubMed ID: 28370589BackgroundCarpal tunnel syndrome (CTS) is a common neurologic impairment caused by injury on the median nerve in the wrist, characterized by pain and loss of sensory. CTS usually occurs through three factors, such as a mechanical pressure on median nerve, immunologic changes, and oxidative stress. The aim of this study was to evaluate the influence of interleukin-1 receptor antagonist (IL-1Ra) and angiotensin-converting enzyme (ACE) I/D polymorphisms on the susceptibility of patients to the CTS. MethodsOne hundred fifty-eight patients with CTS and 151 healthy controls were enrolled in this study. Each patient was analyzed according to diseases symptoms, such as gender, a positive Tinel's sign, a positive Phalen maneuver, disease sides, EMG findings, and clinical stage. We applied the polymerase chain reaction (PCR) to determine the polymorphisms of IL-1Ra and ACE I/D. ResultsThe statistically significant relation was not found between IL-1Ra, ACE I/D polymorphisms and CTS (respectively, P>.05; P>.05, OR: 1.51, CI: 0.82-1.61). Additionally, in the result of the statistical analysis compared with gene polymorphisms and clinical characteristics, we did not find any correlation (P>.05). ConclusionsOur findings showed that there are no associations of IL-1Ra and ACE I/D polymorphisms with susceptibility of a person for the development of CTS. So, it means that these polymorphisms do not create a risk for the development of CTS. Further studies with larger populations will be required to confirm these findings in different study populations

Relationship between retinal sensitivity and disease activity in patients with psoriasis vulgaris

OBJECTIVES: Psoriasis is a hyperproliferative chronic inflammatory skin disease of unknown etiology and ocular structures and visual pathways can also be affected during the course of this disease. Subclinical optic neuritis has previously been observed in psoriatic patients in visual evoked potential studies. This trial was designed to evaluate retinal sensitivity in patients with psoriasis vulgaris. METHODS: A total of 40 eyes of 40 patients with chronic plaque-type psoriasis and 40 eyes of 40 age- and sex-matched control subjects were included in this study. The diagnosis of psoriasis was confirmed by skin biopsy. The severity was determined using the Psoriasis Area and Severity Index and the duration of the disease was recorded. After a full ophthalmological examination, including tests for color vision and pupil reactions, the visual field of each subject was assessed using both standard achromatic perimetry and short wavelength automated perimetry. RESULTS: The mean Psoriasis Area and Severity Index was 22.05±6.40′. There were no significant differences in the visual field parameters of subjects versus controls using either method. There were correlations between disease severity and the mean deviations in standard achromatic perimetry and short wavelength automated perimetry and between disease severity and the corrected pattern standard deviation and pattern standard deviation of short wavelength automated perimetry (r = -0.363, r = -0.399, r = 0.515 and r = 0.369, respectively). CONCLUSIONS: Retinal sensitivity appears to be affected by the severity of psoriasis vulgaris

On the performance of NCC-OFDMA with single relay selection

In this paper, we investigate the outage probability of a network coded cooperation (NCC) system in the presence of frequency selective channels with the usage of orthogonal frequency division multiple access (OFDMA) technique. As OFDMA offers a flexible design of bandwidth usage by letting smart subcarrier allocation schemes in the frequency selective channels, combining NCC with OFDMA leads to feasible transmission schemes for efficient resource utilization. A single relay selection (SRS) technique is used to alleviate the complexity of utilizing all relay nodes. This system model is referred to as NCC-OFDMA-SRS. The first approximation of outage probability expressions of the NCC-OFDMA-SRS system is derived, and the results are supported by extensive simulations. In addition, asymptotic outage probability expressions are obtained, showing that the achievable maximum diversity gain results are attained

An Experimental Study of NOMA for Connected Autonomous Vehicles

Connected autonomous vehicles (CAV) constitute an important application of future-oriented traffic management .A vehicular system dominated by fully autonomous vehicles requires a robust and efficient vehicle-to-everything (V2X) infrastructure that will provide sturdy connection of vehicles in both short and long distances for a large number of devices, requiring high spectral efficiency (SE). Power domain non-orthogonal multiple access (PD-NOMA) technique has the potential to provide the required high SE levels. In this paper, a vehicular PD-NOMA testbed is implemented using software defined radio (SDR) nodes. The main concerns and their corresponding solutions arising from the implementation are highlighted. The bit error rates(BER) of vehicles with different channel conditions are measured for mobile and stationary cases. The extent of the estimation errors on the success rate beyond the idealized theoretical analysis view is investigated and the approaches to alleviate these errors are discussed. Finally, our perspective on possible PD-NOMA based CAV deployment scenarios is presented in terms of performance constraints and expectancy along with the overlooked open issues.Comment: 7 Pages, 6 figure

Nerve conduction studies in the early diagnosis of amyotrophic lateral sclerosis and the importance of split-hand phenomenon

Aim: The heterogeneity of the Amyotrophic Lateral Sclerosis (ALS) clinical phenotypes leads to difficulties in early diagnosis. The ‘split hand’ sign is defined as the thenar muscles that are more prominently affected by hypothenar. In this study, the results of the initial nerve conduction study of the patients were compared with those of the controls in order to increase the findings supporting early diagnosis. Material and Method: Seventy-five patients who were diagnosed with ALS in our clinic were included in the study. The initial ENMG findings of the patients were compared with those of 70 healthy controls: Distal motor latency (DML), the compound muscle action potential (CMAP) amplitude, velocity in the motor conduction of median, ulnar, peroneal and tibial nerves; distal latency, amplitude, velocity in sensorial conduction were evaluated. Ulnar/median DML and ulnar/median CMAP amplitude ratios were examined. Results: In ALS group, DMLs of the median, ulnar, peroneal, and tibial nerves were significantly longer, and CMAP amplitudes were significantly smaller than those of the controls. The sensory conductions of the median, ulnar, and sural nerves were not statistically different between the groups. The ulnar/median DML ratio of the patients was lower than the ratio of controls (0.73/0.80;p=0.003); while the ulnar/median CMAP amplitude ratio was greater (1.40/1.11; p=0.002). Conclusion: Prolonged DML and reduced amplitudes were observed in the motor nerve conduction of ALS patients in the early period. The results of the present study also support the presence of split-hand phenomenon even in early period of limb-onset ALS (both upper and lower). These findings suggest that nerve conduction studies and electrophysiologically detected split-hand sign are important clues for the early diagnosis of ALS in case of heterogeneous clinical phenotype

On the decoding failure probability of random network coded cooperation

This paper considers a network of source nodes that transmit data packets to a destination node via relay nodes over erasure channels by using random linear network coding. The probability that the destination node will fail to recover the packets of all source nodes has been bounded and approximated in the literature for the case of relay nodes that randomly assign only nonzero values to the coefficients of linear combinations of data packets. The paper argues for the necessity of giving relay nodes the choice to also assign the zero value to coefficients when arithmetic operations are over finite fields of small size, e.g. GF(2). Alternative probability mass functions for the coefficients are considered, and expressions for the decoding failure probability are re-derived