Miracle-dz/UniFAR-FTUs huggingface dataset:
Performance of 1-D and 2-D OCDMA systems in presence of atmospheric turbulence and various weather conditions

In this study, the authors compare the performance of one-dimensional (1D) and two-dimensional (2D) optical code division multiple access (OCDMA) systems in presence of turbulence and various weather conditions. Lognormal fading model is used for analysis of weak turbulence and gamma–gamma model for moderate and strong turbulence. It is observed that presence of moderate and strong turbulence may lead to a complete link failure in 2D OCDMA system depending upon the number of users and turbulence level. The various weather conditions considered are very clear air, light fog and thick fog. The results show that the performance degradation due to thick fog is more than the light fog and very clear air in all turbulence regimes.
Optimization of neutral shift in cell-fault treatment for cascaded H-bridge inverter

To improve the output performance of cascaded H-bridge multilevel inverter under faulty conditions, this paper presents an optimized method suitable for harmonic cancellation while the faulty inverter are operated with neutral shift. With some parameters adjusted according to the fault type, the line to line voltages of the cell-fault inverter are increased than traditional control method, while keeping balanced and less distorted; the reliability of the system is then enhanced. The experimental results verify the validity of the proposed method.
Reception of Environmental Sounds Through Cochlear Implants

Objective: The objective of this study was to measure the performance of persons with cochlear implants on a test of environmental-sound reception. Design: The reception of environmental sounds was studied using a test employing closed sets of 10 sounds in each of four different settings (General Home, Kitchen, Office, and Outside). The participants in the study were 11 subjects with cochlear implants. Identification testing was conducted under each of the four closed sets of stimuli using a one-interval, 10-alternative, forced-choice procedure. The data were summarized in terms of overall percent correct identification scores and information transfer (IT) in bits. Confusion patterns were described using a hierarchical-clustering analysis. In addition, individual performance on the environmental-sound task was related to the ability to recognize isolated words through the cochlear implant alone. Results: Levels of performance were similar across the four stimulus sets. Mean scores across subjects ranged from 45.3% correct (and IT of 1.5 bits) to 93.8% correct (and IT of 3.1 bits). Performance on the environmental-sound identification test was roughly related to NU-6 word recognition ability. Specifically, those subjects with word scores greater than 34% correct performed at levels of 80 to 94% on environmental-sound recognition, whereas subjects with word scores less than 34% had greater difficulty on the task. Results of the hierarchical clustering analysis, conducted on two groups of subjects (a high-performing [HP] group and a low-performing [LP] group), indicated that confusions were confined to three or four specific stimuli for the HP subjects and that larger clusters of confused stimuli were observed in the data of the LP group. Signals with distinct temporal-envelope characteristics were easily perceived by all subjects, and confused items tended to share similar overall durations and temporal envelopes. Conclusions: Temporal-envelope cues appear to play a large role in the identification of environmental sounds through cochlear implants. The finer distinctions made by the HP group compared with the LP group may be related to a better ability both to resolve temporal differences and to use gross spectral cues. These findings are qualitatively consistent with patterns of confusions observed in the reception of speech segments through cochlear implants.
Diagnostic Testing with Maple T.A.

At the University of Amsterdam we use the Maple T.A. system for diagnostic testing of incoming mathematics and science students. Purpose of the tests is to identify students at risk of failing their mathematics and science courses in the first year and to provide students insight in their starting level of mathematical knowledge and skills. In this paper we describe our experiences with Maple T.A.
Forms of cannabis and cocaine: A twin study

Cannabis and cocaine are illicit psychoactive substances that have fallen under intense scrutiny by epidemiologists and behavioral geneticists. However, most analyses have used a composite variable to represent the use of these two drugs. For example, the composite variable of cannabis use often includes use of marijuana or hashish. Similarly, cocaine use involves different preparations (crack vs. cocaine hydrochloride) and varying routes of administration (intranasal insufflation vs. smoking). While there is some epidemiological evidence for the difference in addictive potentials between crack and intranasal cocaine, genetically informative studies have not examined the relationship between the forms of cannabis or cocaine. We used data from male and female same‐sex twin pairs to examine the extent of genetic, shared environmental, and unique environmental overlap between (i) marijuana and hashish for cannabis use and (ii) intranasal and crack cocaine for cocaine use. Bivariate Cholesky models were fit using the structural equation modeling software Mx. Our results indicate that for both drugs, the individual drug forms show a complete overlap of genetic factors and a substantial overlap of shared environmental influences. While marijuana and hashish share a moderate proportion of their unique environment, crack and intranasal cocaine only show a modest overlap of unique environmental factors, adding some evidence for form‐specific environmental factors. In conclusion, there is substantial overlap of familial factors between forms of a single drug and preference is primarily determined by unique environmental influences. These findings also reinforce the validity of composite variables in epidemiological and genetic research. © 2004 Wiley‐Liss, Inc.
White cell accumulation in dependent legs of patients with venous hypertension: a possible mechanism for trophic changes in the skin

The mechanism by which chronic venous insufficiency and venous hypertension are associated with ulceration of the legs is not yet understood. To investigate this mechanism further accumulation of white cells in the dependent legs of normal volunteers, patients awaiting surgery for simple varicose veins, and patients with chronic venous insufficiency was studied. About 24% fewer white cells than in normal subjects left the dependent foot of patients with venous hypertension, and this trapping of white cells, was reversed when the foot was raised; similar changes were not observed in normal subjects or patients with varicose veins. The trophic skin changes typically seen in patients with venous hypertension may be aggravated by damage caused by the repeated accumulation of white cells in the microcirculation.
1 REACTION MECHANISM OF SUPEROXIDE GENERATION DURING UBIQUINOL OXIDATION BY THE CYTOCHROME bc 1 COMPLEX *

REACTION MECHANISM OF SUPEROXIDE GENERATION DURING UBIQUINOL OXIDATION BY THE CYTOCHROME bc1 COMPLEX * Ying Yin , Shaoqing Yang , Linda Yu and Chang-An Yu 1 From the Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma, 74078 Running Title: Generation of Superoxide Address correspondence to: Chang-An Yu, Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078. Tel: 405-744-6198; Fax: 405-744-7799; E-mail: cayuq@okstate.edu
Resource Allocation in Relay Enhanced Broadband Wireless Access Networks

The use of relay nodes to improve the performance of BWA networks has been the subject of intense research activities in recent years. Relay enhanced BWA networks are anticipated to support multimedia traffic (i.e., voice, video, and data traffic). In order to guarantee service to network users, efficient resource distribution is imperative. Wireless multihop networks are characterized by two inherent dynamic characteristics: 1) the existence of wireless interference and 2) mobility of user nodes. Both mobility and interference greatly influence the ability of users to obtain the necessary resources for service. In this dissertation we conduct a comprehensive research study on the topic of resource allocation in the presence of interference and mobility. Specifically, this dissertation investigates the impact interference and mobility have on various aspects of resource allocation, ranging from fairness to spectrum utilization. We study four important resource allocation algorithms for relay enhanced BWA networks. The problems and our research achievements are briefly outlined as follows. First, we propose an interference aware rate adaptive subcarrier and power allocation algorithm using maximum multicommodity flow optimization. We consider the impact of the wireless interference constraints using Signal to Interference Noise Ratio (SINR). We exploit spatial reuse to allocate subcarriers in the network and show that an intelligent reuse of resources can improve throughput while mitigating the impact of interference. We provide a sub-optimal heuristic to solve the rate adaptive resource allocation problem. We demonstrate that aggressive spatial reuse and fine tuned-interference modeling garner advantages in terms of throughput, end-to-end delay and power distribution. Second, we investigate the benefits of decoupled optimization of interference aware routing and scheduling using SINR and spatial reuse to improve the overall achievable throughput. We model the routing optimization problem as a linear program using maximum concurrent flows. We develop an optimization formulation to schedule the link traffic such that interference is mitigated and time slots are reused appropriately based on
Identifying key success factors in upstream sector of oil and gas industry in Iran

In today’s global economy, to remain competitive, firms often concentrate and excel at only a few factors as primary determinants of success, known as key success factors (KSF). KSF are specific to industry, sector of an industry, and geography. As such, scope of our study is about identifying KSF of the upstream sector of oil and gas industry due to global attentions to limited natural resources and importance of efficiency in the oil and gas value chain. Furthermore, we considered the case of Iran as one of the oil and gas suppliers in the Middle East. In this research, we employed a hybrid approach to identify KSF. Specifically, we tried to identify KSF based upon perception of managers and experts in the industry at the same time that we investigated the competencies of successful firms in the industry. Among other findings, results indicate that top three KSF are: competency of human resources, sufficiency of financial resources and adequacy of technological capabilities. The results of this study have been also contrasted to the findings of other research work. Findings of this explorative study provide a basis to propose some hypothesis, which could be subject of the further research. Key words: Key success factors, oil and gas industry, theoretical framework, comparative analysis.
On the robust control of robot manipulators including actuator dynamics

A simple robust nonlinear control law that incorporates the manipulator dynamics as well as dynamics of actuators is developed in this paper. The inertial parameters of the manipulator and the electrical parameters of the actuators are considered to be of uncertain values. In contrast to the known methods, the presented design procedure is based on less restrictive assumptions regarding to the characteristic of uncertainties. We just propose that unknown parameters are bounded, that is evidently true for any robotic system. Exponential stability of the developed controller is proved by the Lyapunov method. <<ETX>>
A novel non-TOPO route for the synthesis of colloidal CdSe quantum dots with high luminescence and stability

In this work, the synthesis of high quality CdSe Quantum Dots (QD's) with different ligands (Trioctylphosphine oxide (TOPO)/oleic Acid) has been reported. Oleic acid appears to be excellent replacement for TOPO in this reaction as stable CdSe nanocrystals with a narrow size distribution tunable over a broad range of sizes were obtained. This synthesis of high quality CdSe QD's with oleic acid as the capping-ligand without using conventional non-coordinating solvent octadecene has been reported for the first time. The use of safer, cheaper and easily available oleic acid as compared to expensive, hazardous and toxic TOPO is a step towards the development of green chemistry.
Viscoelasticity imaging using ultrasound: parameters and error analysis

Techniques are being developed to image viscoelastic features of soft tissues from time-varying strain. A compress-hold-release stress stimulus commonly used in creep-recovery measurements is applied to samples to form images of elastic strain and strain retardance times. While the intended application is diagnostic breast imaging, results in gelatin hydrogels are presented to demonstrate the techniques. The spatiotemporal behaviour of gelatin is described by linear viscoelastic theory formulated for polymeric solids. Measured creep responses of polymers are frequently modelled as sums of exponentials whose time constants describe the delay or retardation of the full strain response. We found the spectrum of retardation times τ to be continuous and bimodal, where the amplitude at each τ represents the relative number of molecular bonds with a given strength and conformation. Such spectra indicate that the molecular weight of the polymer fibres between bonding points is large. Imaging parameters are found by summarizing these complex spectral distributions at each location in the medium with a second-order Voigt rheological model. This simplification reduces the dimensionality of the data for selecting imaging parameters while preserving essential information on how the creeping deformation describes fluid flow and collagen matrix restructuring in the medium. The focus of this paper is on imaging parameter estimation from ultrasonic echo data, and how jitter from hand-held force applicators used for clinical applications propagate through the imaging chain to generate image noise.
A Variable Structure MRAC for a Class of MIMO

A Variable Structure Model Reference Adaptive Controller using state variables is proposed for a class of multi input– multi output systems. Adaptation law is of variable structure type and switching functions is designed based on stability requirements. Global exponential stability is proved based on Lyapunov criterion. Transient behavior is analyzed using sliding mode control and shows perfect model following at a finite time. Keywords—Adaptive control, Model reference, Variable structure, MIMO system.
Effects of four maintenance programs on the long-term management of obesity.

This study evaluated the effectiveness of four posttreatment programs designed to enhance the long-term maintenance of weight loss. Mildly and moderately obese adults (N = 123) were randomly assigned to one of the following five conditions: (a) behavior therapy only; (b) behavior therapy plus a posttreatment therapist-contact maintenance program; (c) behavior therapy plus posttreatment therapist contact plus a social influence maintenance program; (d) behavior therapy plus posttreatment therapist contact plus an aerobic exercise maintenance program; or (e) behavior therapy plus posttreatment therapist contact plus both the aerobic exercise and social influence maintenance programs. All posttreatment programs were conducted in 26 biweekly sessions during the year following behavioral treatment for obesity. At an 18-month follow-up evaluation, all four conditions that combined behavior therapy with a posttreatment maintenance program yielded significantly greater long-term weight losses than behavior therapy alone.
Suicide and occupation: the impact of socio-economic, demographic and psychiatric differences

ABSTRACT Background To explore the risk of suicide associated with occupation while evaluating the impact of socio-economic, demographic and psychiatric differences. Method A nested case–control study with 3195 suicides and 63 900 matched controls. Information on causes of death, occupation, psychiatric admission, marital status and socio-economic factors was obtained from routine registers. Results Across the 55 occupations investigated, the risk of suicide ranged from 2·73 [95% confidence interval (CI) 1·77–4·22] among doctors to 0·44 (95% CI 0·27–0·72) among architects and engineers compared with primary school teachers. With the exception of doctors and nurses, most of the excess risk of suicide associated with particular occupations is explained by the social and economic characteristics of people in those occupations. Much, but not all, of the excess risk in doctors and nurses is due to their increased use of self-poisoning, a method for which they have the knowledge to use effectively. Occupation has little association with suicide among people who suffer from a psychiatric illness, except for doctors, where the excess risk is 3·62 (p=0·007). Conclusions Most of the considerable variation in suicide risk across occupations is explained by socio-economic factors, except for doctors and nurses. Apart from in doctors, the risk of suicide has little association with occupation among people who suffer from a psychiatric illness. Restriction of access to lethal means is an important strategy in suicide prevention.
Inverse dynamics and feedforward controllers for high precision position/force tracking of flexible joint robots

SUMMARY A nonlinear feedback control based on inverse dynamics is proposed for robots with flexible joints during constrained motion task execution. Based on constrained system formalism, the presented control scheme achieves simultaneous, independent control of both position and contact force at the robot end-effector. The method can be directly applied to robot control, or it can be used as the basis for developing other advanced control strategies. In this paper, a. feedforward controller is considered. Issues related to the practical application of the full inverse dynamics and feedforward control algorithms, such as evaluation of feedback variables, the use of predictors to eliminate the time delay of digital control, and the design of robust controllers, are discussed. The results of extensive numerical simulation are used to show the effectiveness of the proposed controllers and to compare their performances. It is shown that it is possible to achieve high precision tracking if the appropriate predictors are used to eliminate the effect of computational delay of the digital controller. Applying a straightforward approach for robustness of the proposed controllers has additionally improved the trajectory tracking accuracy.
Ankara Üniversitesi Eğitim Bilimleri Fakültesi programlarının değerlendirilmesi

Bu calismada, Egitim Bilimleri Fakultesinin programlari; amaclar, kapsam, surecler yonunden incelenmistir. “Program Gelistirmede-Seminer ve uygulama” dersinin somestir plâni cercevesinde yurutulen bu calisma, ayni zamanda, yaparak ve yasayarak ogrenmenin universite duzeyde uygulanmasina bir ornek katmistir.
A geometric interpretation of the permutation $p$-value and its application in eQTL studies

Permutation $p$-values have been widely used to assess the significance of linkage or association in genetic studies. However, the application in large-scale studies is hindered by a heavy computational burden. We propose a geometric interpretation of permutation $p$-values, and based on this geometric interpretation, we develop an efficient permutation $p$-value estimation method in the context of regression with binary predictors. An application to a study of gene expression quantitative trait loci (eQTL) shows that our method provides reliable estimates of permutation $p$-values while requiring less than 5% of the computational time compared with direct permutations. In fact, our method takes a constant time to estimate permutation $p$-values, no matter how small the $p$-value. Our method enables a study of the relationship between nominal $p$-values and permutation $p$-values in a wide range, and provides a geometric perspective on the effective number of independent tests.
p 53 as a Specific Prognostic Factor in Triple-negative Breast Cancer

Objective: A recent suggestion is that the predictive value of a single biomarker may rely on the genetic background on the tumor and that different breast cancer subgroups may have different predictive markers of response to chemotherapy. The prognostic value of p53 in the outcome of adjuvant anthracycline-containing chemotherapy was evaluated according to molecular subclasses defined using the expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Methods: Subjects were patients (n 1⁄4 135) with invasive ductal carcinoma treated with adjuvant anthracycline-based chemotherapy between 1994 and 2000 in our hospital. Clinicopathological features were reviewed by retrospective examination of medical records. Results: Overall survival rate was not independently predictive by p53 status (P 1⁄4 0.182). However, in triple-negative cases, there was statistically significant survival difference (P 1⁄4 0.034) and no statistically significant difference (P 1⁄4 0.783) in non-triple-negative cases by p53 status. In the Cox proportional hazard analysis, p53 was also strongly predictive for relapse-free survival (P 1⁄4 0.013) and overall survival (P 1⁄4 0.049) in triple-negative patients. Conclusions: p53 status could be a specific prognostic factor in triple-negative breast cancer patients treated by adjuvant anthracycline-based regimen. When p53 is positive in triple-negative breast cancer, we could expect poor survival, prompting aggressive or alternative treatment.
Covalent bond changes as a driving force in enzyme catalysis.

A procedure is developed for assessing covalent and noncovalent aspects of the acylation of alpha-chymotrypsin (alpha-Ct) by the substrate trifluoroethyl furoate (S) to form furoyl-chymotrypsin (F-Ct) and trifluoroethanol (P1). The free energy change (-4.31 kcal/mol) for the acylation at pH 7, alpha-Ct+S <--> F-Ct+P1, contains contributions from covalent bond changes as well as noncovalent changes. The noncovalent changes are considered to be manifested in the structures of alpha-Ct and F-Ct, and a noncovalent free energy difference between alpha-Ct and F-Ct has been evaluated from the difference in unfolding free energy changes for these proteins. The unfolding free energy changes demonstrate that F-Ct is 1.6 kcal/mol less stable than alpha-Ct at pH7. Thus, despite an overall favorable free energy change for acyl-enzyme formation (-4.31 kcal/mol), covalent linkage of the furoyl moiety to the active site is thermodynamically destabilizing to the enzyme. The consequence of this unfavorable effect of the furoyl moiety on the noncovalent free energy is that "binding" of the covalently linked furoyl moiety cannot be the driving force for acylation. The source of free energy driving acylation is the covalent bond-breaking and bond-making involved in transesterification of the furoyl group to the enzyme. Since the (noncovalent) Michaelis complex between alpha-Ct and substrate is significantly more stable (thermodynamically) than F-Ct, a substantial amount of noncovalent free energy must be given up on forming F-Ct. The destabilization residing in F-Ct is consistent with the possibility that energy transduction occurs when the Michaelis complex is converted to F-Ct and that destabilization is relieved on reaching the next activated complex.