186 research outputs found

    AN INVESTIGATION OF SECURITY CHALLENGES IN COGNITIVE RADIO NETWORKS

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    The recent advances in wireless communication have led to the problem of growing spectrum scarcity. The available wireless spectrum has become scarcer due to increasing spectrum demand for new wireless applications. The large portion of the allocated spectrum is sporadically used leading to underutilization of significant amount of spectrum. To improve the spectrum efficiency, the idea of cognitive radio technology was introduced. This concept of cognitive radio provides a promising solution for the spectrum scarcity issues in wireless networks. Meanwhile, the security issues of cognitive radio have received more attentions recently since the inherent properties of CR networks would pose new challenges to wireless communications. In this MS thesis, general concepts of security threats to the cognitive radio networks are briefly reviewed. Performances for primary user emulation attacks are studied from Neyman-Pearson criterion point of view. A novel system model with different configurations of the primary users has been proposed and studied. Our experimental results demonstrate the statistical characteristics of the probability of false alarm and miss detection in the proposed system. I will make performance comparison with others’ research in the future. Adviser: Yaoqing Yan

    AN INVESTIGATION OF SECURITY CHALLENGES IN COGNITIVE RADIO NETWORKS

    Get PDF
    The recent advances in wireless communication have led to the problem of growing spectrum scarcity. The available wireless spectrum has become scarcer due to increasing spectrum demand for new wireless applications. The large portion of the allocated spectrum is sporadically used leading to underutilization of significant amount of spectrum. To improve the spectrum efficiency, the idea of cognitive radio technology was introduced. This concept of cognitive radio provides a promising solution for the spectrum scarcity issues in wireless networks. Meanwhile, the security issues of cognitive radio have received more attentions recently since the inherent properties of CR networks would pose new challenges to wireless communications. In this MS thesis, general concepts of security threats to the cognitive radio networks are briefly reviewed. Performances for primary user emulation attacks are studied from Neyman-Pearson criterion point of view. A novel system model with different configurations of the primary users has been proposed and studied. Our experimental results demonstrate the statistical characteristics of the probability of false alarm and miss detection in the proposed system. I will make performance comparison with others’ research in the future. Adviser: Yaoqing Yan

    Malignant nodular hidradenoma-inguinal region clinically masquerading as squamous cell carcinoma: a case report

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    Malignant Nodular hidradenoma is an extremely rare aggressive tumour originating from eccrine sweat glands with an incidence of <.001%. So far less than 80 cases have been reported in the literature. It’s known for its local recurrence (50%) and metastasis (60%) and hence early diagnosis and radical treatment is mandatory. But differentiating it from its benign counterparts and other skin tumour mimics is challenging, due to its histopathological similarity & lack of diagnostic immunomarkers. Authors report a case of 65-year-old female who presented with a short 4-month history of rapidly growing ulceroproliferative growth in the right inguinal region with bilateral inguinal node enlargement, associated with pain and discharge. Wedge biopsy of left inguinal lymph node showed malignant cutaneous adnexal tumour deposits, which after excision was typed as malignant nodular hidradenoma. It was confirmed with immunohistochemistry. Patient presented with recurrence 8 months after excision

    Fluxes of heat and momentum over sea surface during the passage of Δ depression in the north Bay of Bengal

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    Tims variation of surface Fluxes of heat, moisture and momentum over a sea station (20:N89E) in the norm Bay of Bengal Mas been computed bv srofiie method lor the Period IK;:-, 25th Angus; 1990 using meteorological data of MOSTBL EX-90 from OR Y Sayarkniyii. The fluxes showed synoptic and uiurnal variations nnich ars rrarked during oppression (20th-21st August) comparée to their variation prior to and after tais period. Variations of heal and water vapour fluxes were in phase. Nigh- time fluxes are ralati.eiy high ccmpared to day time. Average ir.orner.tam transfer during depressor. two io three times large. Variations in Bowen ratio wers relatively large during day time. During depression, it varied between 0-2 in day lime and about 00 A., nignt and in the undisturbed period between 0-1 jnd 0-2 during day time and 0-2 and 025 at nigh:. The study shows that the assumption of the exchange coefficients normaiiy used ir. estimating the Ruxes by the buk Lu-rodyr.umic method is not appropriate because Cy/C- C and CH/C14

    A clinico-pathological study of lichenoid tissue reactions/interface dermatitis

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    Background: Lichenoid tissue reaction/Interface dermatitis (LTR/ID) refers to a number of clinically diverse, poorly understood and relatively uncommon inflammatory skin diseases. This study was done to understand the histopathological features of lichenoid tissue reactions in skin biopsies and to assess the concordance and disparity between the clinical and histopathological diagnosis of variants of the same.Methods: It was a 3œ years study from January 2014 to June 2017 in the department of Pathology, KIMS, Hubballi. The present study included skin biopsies of clinically diagnosed and suspected cases and histologically diagnosed cases of LTRs. Skin biopsies received were routinely paraffin processed and H&E stained to study the microscopic features.Results: Out of 166 skin biopsies studied, 148 were histologically confirmed as LTR with majority being of lichen planus (LP) (91.22%). Classical lichen planus was the most common variant of lichen planus among lichen planus cases. Male:female ratio was 1.2:1. Clinico-pathological concordance was seen in 88.55% of the cases.Conclusions: Though definite diagnosis can be made on histopathological examination, size of specimen, site of biopsy, nature and depth of biopsy, quality of sections, treatment history and inter-observer variation (both clinically and histologically) should be kept in mind which may lead to clinicopathological discordance

    Parachordoma: a rare recurring case at a rare site

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    Parachordoma is an uncommon tumor of soft tissue and the orign is not clear. This soft tissue tumor resembles chordomas as well as extraskeletal myxoid chondrosarcomas and has only recently been fully characterized. Although it is considered a benign lesion, its behavior tends to be locally aggressive, with reports of a recurrence rate of up to 20% and of several cases of metastasis. In this article, we report a case of parachordoma in the neck with recurrence that we met in clinical works

    Preconception nutrition intervention improved birth length and reduced stunting and wasting in newborns in south Asia: The women first randomized controlled trial

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    South Asia has \u3e50% of the global burden of low birth weight (LBW). The objective was to determine the extent to which maternal nutrition interventions commenced before conception or in the 1st trimester improved fetal growth in this region. This was a secondary analysis of combined newborn anthropometric data for the South Asian sites (India and Pakistan) in the Women First Preconception Maternal Nutrition Trial. Participants were 972 newborn of mothers who were poor, rural, unselected on basis of nutritional status, and had been randomized to receive a daily lipid-based micronutrient supplement commencing ≄3 months prior to conception (Arm 1), in the 1st trimester (Arm 2), or not at all (Arm 3). An additional protein-energy supplement was provided if BMI/m2 or gestational weight gain was less than guidelines. Gestational age was established in the 1st trimester and newborn anthropometry obtaine

    Duration of third stage labour and postpartum blood loss: a secondary analysis of the WHO CHAMPION trial data

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    Background: Obstetric haemorrhage continues to be a leading cause of maternal mortality, contributing to more than a quarter of the 2,443,000 maternal deaths reported between 2003 and 2009. During this period, about 70% of the haemorrhagic deaths occurred postpartum. In addition to other identifiable risk factors for greater postpartum blood loss, the duration of the third stage of labour (TSL) seems to be important, as literature shows that a longer TSL can be associated with more blood loss. To better describe the association between the duration of TSL and postpartum blood loss in women receiving active management of third stage of labour (AMTSL), this secondary analysis of the WHO CHAMPION trial data has been conducted. Methods: This was a secondary analysis of the WHO CHAMPION trial conducted in twenty-three sites in ten countries. We studied the association between the TSL duration and blood loss in the sub cohort of women from the CHAMPION trial (all of whom received AMTSL), with TSL upto 60 min and no interventions for postpartum haemorrhage. We used a general linear model to fit blood loss as a function of TSL duration on the log scale, arm and center, using a normal distribution and the log link function. We showed this association separately for oxytocin and for Heat stable (HS) carbetocin. Results: For the 10,040 women analysed, blood loss rose steeply with third stage duration in the first 10 min, but more slowly after 10 min. This trend was observed for both Oxytocin and HS carbetocin and the difference in the trends for both drugs was not statistically significant (p-value = 0.2070). Conclusions: There was a positive association between postpartum blood loss and TSL duration with either uterotonic. Blood loss rose steeply with TSL duration until 10 min, and more slowly after 10 min.Fil: Chikkamath, Sumangala B.. S. Nijalingappa Medical College; IndiaFil: Katageri, Geetanjali M.. S. Nijalingappa Medical College; IndiaFil: Mallapur, Ashalata A.. S. Nijalingappa Medical College; IndiaFil: Vernekar, Sunil S.. Jawaharlal Nehru Medical College Belgaum; IndiaFil: Somannavar, Manjunath S.. Jawaharlal Nehru Medical College Belgaum; IndiaFil: Piaggio, Gilda. No especifĂ­ca;Fil: Carroli, Guillermo. Centro Rosarino de Estudios Perinatales; ArgentinaFil: de Carvalho, JosĂ© Ferreira. No especifĂ­ca;Fil: Althabe, Fernando. Organizacion Mundial de la Salud; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂ­a y Salud PĂșblica. Instituto de Efectividad ClĂ­nica y Sanitaria. Centro de Investigaciones en EpidemiologĂ­a y Salud PĂșblica; ArgentinaFil: Hofmeyr, G. Justus. University of Botswana; Estados Unidos. University of the Witwatersrand; SudĂĄfricaFil: Widmer, Mariana. Organizacion Mundial de la Salud; ArgentinaFil: Gulmezoglu, Ahmet Metin. No especifĂ­ca;Fil: Goudar, Shivaprasad S.. Jawaharlal Nehru Medical College Belgaum; Indi
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