Verification of Localization via Blockchain Technology on Unmanned Aerial Vehicle Swarm

Verification of the geographic location of a moving device is vital. This verification is important in terms of ensuring that the flying systems moving in the swarm are in orbit and that they are able to task completion and manage their energy efficiency. Cyber-attacks on unmanned aerial vehicles (UAV) in a swarm can affect their position and cause various damages. In order to avoid this challenge, it is necessary to share with each other the positions of UAV in the swarm and to increase their accuracy. In this study, it is aimed to increase position accuracy and data integrity of UAV by using blockchain technology in swarm. Experiments were conducted on a virtual UAV network (UAVNet). Successful results were obtained from this proposed study

The Impact of Futures Trading Over Spot Market Intraday Volatility: Evidence From an Emerging Market, Borsa Istanbul

The objective of this article is to examine the impact of stock index futures on stock markets.  Of particular interest is the evidence for change in overall volatility and liquidity after the introduction of stock index futures. The impact of derivatives trading on price volatility in the underlying spot market return is examined using the exponential GARCH (EGARCH) model which was proposed by Nelson (1991). Our empirical findings support the view that introducing futures trading decreases volatility in the spot market and the speed with which market information is reflected in spot market prices. However, volatility persistence increased in the post-futures period. In the light of these findings it can be said that the speed and nature of information differ between pre-futures period and post-futures period. JEL Classification: G13, G14, G32 Keywords: Futures Markets, Spot Markets, Volatility, GARCH Models, Emerging Markets DOI: 10.7176/RJFA/10-2-0

Tree-Seed Algorithm for Large-Scale Binary Optimization

Population-based swarm or evolutionary computation algorithms in optimization are attracted the interest of the researchers due their simple structure, optimization performance, easy-adaptation. Binary optimization problems can be also solved by using these algorithms. This paper focuses on solving large scale binary optimization problems by using Tree-Seed Algorithm (TSA) proposed for solving continuous optimization problems by imitating relationship between the trees and their seeds in nature. The basic TSA is modified by using xor logic gate for solving binary optimization problems in this study. In order to investigate the performance of the proposed algorithm, the numeric benchmark problems with the different dimensions are considered and obtained results show that the proposed algorithm produces effective and comparable solutions in terms of solution quality.Keywords: binary optimization, tree-seed algorithm, xor-gate, large-scale optimizatio

ARI KOLONİSİ OPTİMİZASYON ALGORİTMASI KULLANARAK ŞOFÖRHAT-ZAMAN ÇİZELGELEME

Bu çalışmadaki şoför-hat-zaman çizelgeleme problemi şehir içi hatlarda çalışan toplu taşıma araçlarının seferlerinin şoförler için çizelgelenmesini kapsar. Genellikle birçok hatta ait birçok sefer aynı istasyondan başlamak suretiyle hattın güzergâhında halka şeklinde icra edilmektedir. Yolcular duraklarda bulunan listeler yardımıyla bekledikleri otobüslerin ne zaman geleceğini tespit ederler. Bu listeler yolcuların gün içindeki yoğunluk durumu düşünülerek hazırlanır ve ayrıca listelerdeki seferleri icra edecek şoförler içinde çizelgelenmesi gerekir. Seferlerin şoförler için çizelgelenmesi hali hâzırda istasyon sorumlusu tarafından yürütülmektedir. Sefer sayısının fazla olması durumunda çözüm uzayı genişlemesi istasyon sorumlusunun olası en iyi çözümleri gözden kaçırmasına neden olur. Bu çalışmada Arı Kolonisi Optimizasyon algoritması hatta ait seferlerin şoförler için çizelgelenmesi amacıyla kullanılmıştır. Sonuçlar hâli hazırda kullanılmakta olan çözüm ile kıyaslanmıştır. Önerilen yöntem ile elde edilen sonuçlar şoför sayısı, dinlenme süresi, yemek molası kriterlerine göre hâli hazırda kullanılan çözümden daha iyidi

Tunable Room Temperature THz Sources Based on Nonlinear Mixing in a Hybrid Optical and THz Micro-Ring Resonator

We propose and systematically investigate a novel tunable, compact room temperature terahertz (THz) source based on difference frequency generation in a hybrid optical and THz micro-ring resonator. We describe detailed design steps of the source capable of generating THz wave in 0.5–10 THz with a tunability resolution of 0.05 THz by using high second order optical susceptibility (x(2)) in crystals and polymers. In order to enhance THz generation compared to bulk nonlinear material, we employ a nonlinear optical micro-ring resonator with high-Q resonant modes for infrared input waves. Another ring oscillator with the same outer radius underneath the nonlinear ring with an insulation of SiO2 layer supports the generated THz with resonant modes and out-couples them into a THz waveguide. The phase matching condition is satisfied by engineering both the optical and THz resonators with appropriate effective indices. We analytically estimate THz output power of the device by using practical values of susceptibility in available crystals and polymers. The proposed source can enable tunable, compact THz emitters, on-chip integrated spectrometers, inspire a broader use of THz sources and motivate many important potential THz applications in different fields

Results of Resection of Giant Pituitary Adenomas through Endoscopic Endonasal Approach

Background/Objective:  A minimally invasive surgical method is in use to create endoscopic transsphenoidal surgery. Because of the intricate dissection of the sellar region, surgical treatment of large pituitary adenomas is challenging. The study focused to determine the frequency of complications after endonasal endoscopic transsphenoidal resection of giant pituitary macroadenomas. Materials and Methods:  A descriptive case series study was conducted at the Neurosurgical Department of Lahore General Hospital, Lahore. A total of 70 patients fulfilling the selection criteria were enrolled. Major vascular injury was noted when there is an injury to the internal carotid artery or cavernous sinus. After discharge, patients were followed-up in OPD for 3 months. After 3 months, patients were evaluated for CSF leak and vision. The presence of complications was recorded. During surgery, operative time was noted. Results:  Mean age of patients was 55.7 ± 6.5 years. 45.71% of patients were male while the remaining 54.29% of patients were female Total of 41.43% of patients had disease < 2 years, whereas the duration of surgery was ? 3 hours in 64.3% of patients. A total 15.71% had complications which included diabetes insipidus (8.57%), infections (5.71%), pituitary dysfunction (4.29%), CSF leak (2.8%) and vascular injury (1.43%). The mortality rate was 1.43%. Conclusion:  The complication rate after endonasal endoscopic transsphenoidal resection of giant pituitary macroadenomas was high. Keywords:  Endonasal Endoscopic, Transsphenoidal Resection, Pituitary Macroadenomas, Complication

Comparison of Cerebrospinal Fluid Leakage in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenoma with and without Sellar Floor Reconstruction

Objectives:  This study aimed to compare CSF leak in endoscopic endonasal TSS of pituitary adenoma with and without reconstruction of the sellar floor with no intraoperative CSF leakage. Materials and Methods:  It was a randomized controlled trial of 116 patients of both genders diagnosed case of pituitary adenoma who underwent endoscopic endonasal TSS over 1 year. The cases were randomized into 2 groups. In Group A endoscopic endonasal TSS and the sellar floor, reconstruction was done while in Group B only endoscopic endonasal transsphenoidal surgery was done without reconstruction. Results:  The patient’s mean age in group A was 40.7 ± 9.56 years, and in group, B was 41.9 ± 10.5 years. The gender distribution, for group A, males and females were 29 each (50%) and in group B, the males were 36 (62%) and females were 22 (38%). There were 52 (89.7%) cases of macroadenoma and 6 (10.3%) cases of microadenoma in each group. On the 1st postoperative day, CSF leakage was noted in 2 (3.4%) patients of group A, and CSF leakage was observed in 2 (3.4%) patients of group B. Results revealed no difference in CSF leakage between both groups. There were minor nasal complications in both groups. Conclusion:  There is an equal chance of success with endoscopic endonasal transsphenoidal surgery (TSS) of pituitary adenoma with and without reconstruction of the sellar floor, concerning post-operative CSF leak, in patients who have no intraoperative CSF leak which enlarges the pool of options for treatment

Effects of Organizational Justice on Organizational Commitment

Organizational justice has been considered as an important contributor for commitment of employees towards their organization. Only two dimensions (Distributive and procedural justice) of organizational justice were focused in this study.  This research study is cross sectional in design. For questionnaires distribution a sample size of 500 employees (subjects) were chosen from three higher education institutions of Khyber Pakhtunkhwa, Pakistan.  Data were analyzed by using arithmetic mean, standard deviation, correlation and regression tools and techniques. Results shown that distributive and procedural justice both have noteworthy and positive effects on the dependent variable (organizational commitment) of the employees. Keywords: Organizational Justice, Distributive justice, procedural justice, organizational commitment JEL Classifications: D23, L

Tau PET and multimodal brain imaging in patients at risk for chronic traumatic encephalopathy.

ObjectiveTo characterize individual and group-level neuroimaging findings in patients at risk for Chronic Traumatic Encephalopathy (CTE).MethodsEleven male patients meeting criteria for Traumatic Encephalopathy Syndrome (TES, median age: 64) underwent neurologic evaluation, 3-Tesla MRI, and PET with [18F]-Flortaucipir (FTP, tau-PET) and [11C]-Pittsburgh compound B (PIB, amyloid-PET). Six patients underwent [18F]-Fluorodeoxyglucose-PET (FDG, glucose metabolism). We assessed imaging findings at the individual patient level, and in group-level comparisons with modality-specific groups of cognitively normal older adults (CN). Tau-PET findings in patients with TES were also compared to a matched group of patients with mild cognitive impairment or dementia due to Alzheimer's disease (AD).ResultsAll patients with TES sustained repetitive head injury participating in impact sports, ten in American football. Three patients met criteria for dementia and eight had mild cognitive impairment. Two patients were amyloid-PET positive and harbored the most severe MRI atrophy, FDG hypometabolism, and FTP-tau PET binding. Among the nine amyloid-negative patients, tau-PET showed either mildly elevated frontotemporal binding, a "dot-like" pattern, or no elevated binding. Medial temporal FTP was mildly elevated in a subset of amyloid-negative patients, but values were considerably lower than in AD. Voxelwise analyses revealed a convergence of imaging abnormalities (higher FTP binding, lower FDG, lower gray matter volumes) in frontotemporal areas in TES compared to controls.ConclusionsMildly elevated tau-PET binding was observed in a subset of amyloid-negative patients at risk for CTE, in a distribution consistent with CTE pathology stages III-IV. FTP-PET may be useful as a biomarker of tau pathology in CTE but is unlikely to be sensitive to early disease stages

Assessing the Relation between Mud Components and Rheology for Loss Circulation Prevention Using Polymeric Gels: A Machine Learning Approach

The traditional way to mitigate loss circulation in drilling operations is to use preventative and curative materials. However, it is difficult to quantify the amount of materials from every possible combination to produce customized rheological properties. In this study, machine learning (ML) is used to develop a framework to identify material composition for loss circulation applications based on the desired rheological characteristics. The relation between the rheological properties and the mud components for polyacrylamide/polyethyleneimine (PAM/PEI)-based mud is assessed experimentally. Four different ML algorithms were implemented to model the rheological data for various mud components at different concentrations and testing conditions. These four algorithms include (a) k-Nearest Neighbor, (b) Random Forest, (c) Gradient Boosting, and (d) AdaBoosting. The Gradient Boosting model showed the highest accuracy (91 and 74% for plastic and apparent viscosity, respectively), which can be further used for hydraulic calculations. Overall, the experimental study presented in this paper, together with the proposed ML-based framework, adds valuable information to the design of PAM/PEI-based mud. The ML models allowed a wide range of rheology assessments for various drilling fluid formulations with a mean accuracy of up to 91%. The case study has shown that with the appropriate combination of materials, reasonable rheological properties could be achieved to prevent loss circulation by managing the equivalent circulating density (ECD).This research was funded by Qatar National Research Fund (a member of Qatar Foundation), grant number NPRP10-0125-170240 and The APC was funded by OU Libraries. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye