Rotordynamic Coefficients in Staggered Labyrinth Seals

Eser, Dursun,Dereli, Yilmaz The Korean Society of Mechanical Engineers 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.5

In this paper, the flow properties of staggered labyrinth seals are investigated. Leakage flowrates and pressure distributions are calculated for this seal. Then the dynamic stiffness and damping coefficients are calculated. The results are compared to the results of the some other papers.

Rotordynamic Coefficients in Staggered Labyrinth Seals

Dursun Eser,Yilmaz Dereli 대한기계학회 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.5

In this paper, the flow properties of staggered labyrinth seals are investigated. Leakage flowrates and pressure distributions are calculated for this seal. Then the dynamic stiffness and damping coefficients are calculated. The results are compared to the results of the some other papers.<br/>

Impact of litter on femur and tibial morphology, bone biomechanics, and leg health parameters in broiler chickens

Khan Komal,Kaya Mehmet,Fidan Evrim Dereli,Kilimci Figen Sevil 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.9

Objective: In this study effects of three types of beddings on broiler leg health and bone biomechanics were evaluated. Methods: A total of 504 male chicks (Ross 308) were randomly placed on three beddings (4 replicates/group; 42 birds/pen), zeolite-added litter (ZL), plastic-grid flooring (PF), and wood shavings (WS). On day 42, chickens were weighed, slaughtered, and samples (bone, muscle, and drumstick) were collected. Bones were subjected to leg health tests, morphometric measurements, biomechanical testing, and ash analysis. Results: Broilers in PF and WS groups showed higher live weight than the ZL group (p<0.001), and the incidence of tibial dyschondroplasia (TD) and varus valgus deformity due to distal bending was significantly higher in PF (p<0.001). Multinomial logistic regression showed that bedding has a significant (p = 0.038) contribution toward the development of TD. Tibial strength (p = 0.040), drumstick width (p = 0.001), and total femur and epiphyseal ash contents (p = 0.044, 0.016) were higher in the ZL group. Chicken live weight was correlated with tibial length and weight (r = 0.762, 0.725). Conclusion: Flooring and the type of bedding material directly affect broiler bone length, strength and leg health. Plastic bedding improves the slaughter weight of chickens on the expense of leg deformities, and zeolite litter improves leg health and bone strength.

Combined Effect of Bearing Stiffness of the Base Isolator and Damping Characteristics of the Viscous Damper on the Nonlinear Response of Buildings

Ahmet Hilmi Deringöl,Esra Mete Güneyisi,Osman Hansu 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.5

Recently, the base isolation system (BIS) has been adopted as mature structural protective system which dissipates the most part of the input energy emerged during any type of seismic excitation. However, BIS can induce large displacement because of having easily movement tendency of the bearing. Therefore, this study proposes a set of BIS incorporated with supplementary damping device to control the nonlinear response of the buildings with low and moderate heights. For this, 5 and 10-storey steel moment resisting frames isolated with lead rubber bearing (LRB) with varying stiff ness properties (i.e. high, moderate, and low) were studied. Afterwards, viscous damper (VD) was designed with three diff erent damping exponents of 0.3, 0.6, and 1.0 so that they were alternatively distributed both in inner and corner bays throughout the building heights. The eff ectiveness of the proposed isolation models with and without VDs were evaluated through the nonlinear time history analyses under diff erent earthquake records. Advantages of the developed isolation systems over both the fi xed base and the base isolated frames were discussed in terms of the storey, bearing, and relative displacements, roof and interstorey drift ratios, absolute acceleration, base shear, and hysteretic curves. It was shown that low-stiff ness-LRB (LLRB) associated with the VD of proper damping exponent and implementation layout signifi cantly mitigated the structural response of the buildings.

Effect of Using High Damping Rubber Bearings for Seismic Isolation of the Buildings

Ahmet Hilmi Deringöl,Esra Mete Güneyisi 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.5

In this study, the use of high damping rubber bearing (HDRB) with various design properties in mitigating the seismic eff ects for steel buildings was investigated. For this, a generalized demand on the analytical model of HDRB was introduced and eighteen diff erent models of HDRB were examined comparatively. These models were created by considering three signifi cant isolation parameters of HDRB such as isolation period T (2, 2.5, and 3 s), eff ective damping ratio β (0.05, 0.10, 0.15), and post-yield stiff ness ratio λ (3 and 6). The benchmark low (3-storey), mid (6-storey), and high-rise (9-storey) steel buildings were equipped with diff erent isolation systems of HDRB and then subjected to a set of earthquake ground motions through nonlinear time history analyses in order to evaluate the actual nonlinear behaviour of the bearings in the base-isolated steel buildings in service. The base-isolated frames were assessed by the variation of the selected structural response parameters such as isolator displacement, relative displacement, inter-storey drift ratio, absolute acceleration, base shear, hysteretic curve, and dissipated energy. The eff ectiveness of the isolation parameters on the nonlinear response of the steel buildings with HDRB under earthquakes was comparatively evaluated to generate alternatively innovative isolation system. It was shown that the seismic performance of the base-isolated structure was remarkably infl uenced by the isolation parameters. The most favourable base isolation model was obtained when the higher value of the isolation period and eff ective damping ratio combined with the low post-yield stiff ness ratio.

Comparison and selection of patient follow‑up systems for covid‑19 pandemic patients

Tamer Eren,Tuğba Danışan,Ayşegül Deringöz,Güler Aksüt 한국의류학회 2022 Fashion and Textiles Vol.9 No.1

People have struggled with many infectious diseases throughout history. Today, the Covid-19 is being fought. One of the most important things for people who have or are at risk of getting Covid-19 is social isolation. Many countries resort to diferent ways to ensure social isolation. For this, remote patient monitoring systems have been developed. In this study, the problem of the selection of Covid-19 remote patient monitoring systems is discussed. Seven Wearable Health Technology (WHT) products were evaluated with a total of 10 criteria, including the important symptoms used in the patient tracking systems. The weights of 10 criteria determined by the Analytical Hierarchy Process (AHP) method were calculated, and these weights were used in the solution of The Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE), and Technique for Order Preference by Similarity to Ideal Solutions (TOPSIS) methods. WHT products were compared. As a result, the most appropriate patient follow-up system was determined. This study generates diferences in terms of evaluating seven diferent products and ten criteria in total with MCDM methods. A more comprehensive evaluation has been made in the literature than the studies in this feld.

Prediction of Drug–Drug Interactions by Using Profile Fingerprint Vectors and Protein Similarities

Selma Dere,Serkan Ayvaz 대한의료정보학회 2020 Healthcare Informatics Research Vol.26 No.1

Objectives: Drug–drug interaction (DDI) is a vital problem that threatens people’s health. However, the prediction of DDIs through in-vivo experiments is not only extremely costly but also difficult as many serious side effects are hard to detect in in-vivo and in-vitro settings. The aim of this study was to assess the effectiveness of similarity-based in-silico computational DDI prediction approaches and to provide a cost effective and scalable solution to predict potential DDIs. Methods: In this study, widely known similarity-based computational DDI prediction methods were utilized to discover novel potential DDIs. More specifically, known interactions, drug targets, adverse effects, and protein similarities of drug pairs were used to construct drug fingerprints for the prediction of DDIs. Results: Using the drug interaction profile, our approach achieved an area under the curve (AUC) of 0.975 in the prediction of a potential DDI. The drug adverse effect profile and protein profile similarity-based methods resulted in AUC values of 0.685 and 0.895, respectively, in the prediction of DDIs. Conclusions: In this study, we developed a computational approach to the prediction of potential drug interactions. The performance of the similarity-based computational methods was comparatively evaluated using a comprehensive real-world DDI dataset. The evaluations showed that the drug interaction profile information is a better predictor of DDIs compared to drug adverse effects and protein similarities among DDI pairs.

Applications of umbral algebra to some special polynomials

R. Dere,Y. Simsek 장전수학회 2012 Advanced Studies in Contemporary Mathematics Vol.22 No.3

In this work, we study on umbral algebra and generating functions for the Hermite type Genocchi polynomials and numbers. We introduce some properties of this algebra and polynomials.

Towards On-device Deep Neural Network Inference and Model Update for Real-time Gesture Classification

Mustapha Deji Dere,Jo Ji-hun,Boreom Lee 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

Deep learning resurgence ushered in the application of pattern recognition algorithms in high-impact research fields with impressive accuracy. In addition, deep neural networks (DNN) have recently been used to classify gestures for rehabilitation device control utilizing raw electromyography data. However, the computational resources required by a convolution neural network (CNN) are a constraint that often limits deployment to embedded devices for real-time inference. An optimized edge adaptive convolutional neural network using a short-time Fourier transform (STFT) spectrogram input was proposed in this study. The models classification accuracy was evaluated offline and on-device for inter-subject accuracy. Furthermore, an adaptive weight update approach was implemented to improve inference model accuracy due to degradation. The proposed model and optimization technique achieved offline accuracy of 92.19 % and 94.29 % for the raw and STFT input, respectively. However, the on-device accuracy for raw and STFT input to the model was 82.26 % and 85.19 %, respectively. On the other hand, the adaptive model update increased the respective accuracy by an average of 7% on-device. Finally, our study demonstrates the deployment of DNN on-device for real-time gesture classification inference.

The Effect of Benzene on the Activity of Adenosine Deaminase in Tissues of Rats

Turhan, Ali,Dere, Egemen Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

Swiss Albino (Rat rattus norvegicus) rats were intraperitoneally injected with a 100 mg $kg^{-1}$ dosage of benzene, a toxic and carcinogenic agent widely used for industrial purposes. Changes in the adenosine deaminase (ADA) activity in the liver, kidney and serum of rats were investigated at 0, 2, 4, 8, 16, 32 and 64 h following injection. Serum physiological was administered to each control group. Enzyme activities were measured spectrophotometrically. Our purpose was to further investigations of some diseases caused by benzene, and present evidence of variations in the activity of ADA enzyme effected by benzene. While benzene caused significant inhibitions in ADA activity in the liver at 16 and 32 h and at 0.05 probability level, no significant inhibition or activation occurred at other test periods (hours). ADA activity did not present any significant variation in the kidneys. It was observed that ADA activity displayed similar patterns in the control groups. Comparisons of ADA activities in the two groups showed a statistically significant decrease between $4^{th}$ and $64^{th}$ hours (p< 0.05), demonstrating a direct correlation between benzene and its effects on ADA enzymes.