• Title/Summary/Keyword: experimental techniques

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Common Sites, Etiology, and Solutions of Persistent Septal Deviation in Revision Septoplasty

  • Jin, Hong Ryul;Kim, Dae Woo;Jung, Hahn Jin
    • Clinical and Experimental Otorhinolaryngology
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    • v.11 no.4
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    • pp.288-292
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    • 2018
  • Objectives. To investigate the common causes of persistent septal deviation in revision septoplasty and to report the surgical techniques and results to correct them. Methods. A total of 100 consecutive patients (86 males) who had revision septoplasty due to persistent septal deviation from 2008 and 2014 were included in the study. Their mean age was 35.6 years and the mean follow-up duration was 9.1 months. Presenting symptoms, sites of persistent septal deviation, techniques used to correct the deviation, and surgical results were reviewed. Results. The mean interval between primary and revision surgery was 6.2 years. Forty-eight patients received revision septoplasty and 52 received revision septoplasty combined with rhinoplasty. Nasal obstruction was the most presenting symptom in almost all patients. The most common site of persistent septal deviation was middle septum (58%) followed by caudal septum (31%). Correcting techniques included further chondrotomy and excision of deviated portion in 76% and caudal batten graft in 39%. Rhinoscopic and endoscopic exams showed straight septum in 97% and 92 patients had subjective symptom improvement postoperatively. Conclusion. Middle septum and caudal septum were common sites of persistent deviation. Proper chondrotomy with excision of deviated middle septum and correction of the caudal deviation with batten graft are key maneuvers to treat persistent deviation.

Performance Analysis of Interpolation in Demosaicing Techniques for Single Sensor Digital Camera (단일 센서 디지털 카메라를 위한 디모자이킹 기술에서의 보간법 성능 분석)

  • Synn, Sojung;Yoo, Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.215-218
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    • 2009
  • In this paper, we analyze the performance of interpolation in demosaicing techniques for single sensor digital camera. We choose BI(bilinear interpolation), ACPI(adaptive color plane interpolation), ECI(effective color interpolation), Ideal ACPI, and EECI(Enhanced effective color interpolation) in the literature of demosacing techniques since they provide low-complexity and substantial image quality. We survey the algorithms and simulate them. To evaluate the methods in terms of objective image quality and complexity, 24 Kodak images will be used in this experiment. Experimental results show that the ECI method is better than others in terms of image quality versus complexity.

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An Analysis of Privacy and Accuracy for Privacy-Preserving Techniques by Matrix-based Randomization (행렬 기반 랜덤화를 적용한 프라이버시 보호 기술의 안전성 및 정확성 분석)

  • Kang, Ju-Sung;An, A-Ron;Hong, Do-Won
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.4
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    • pp.53-68
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    • 2008
  • We study on the practical privacy-preserving techniques by matrix-based randomization approach. We clearly examine the relationship between the two parameters associated with the measure of privacy breach and the condition number of matrix in order to achieve the optimal transition matrix. We propose a simple formula for efficiently calculating the inverse of transition matrix which are needed in the re-construction process of random substitution algorithm, and deduce some useful connections among standard error and another parameters by obtaining condition numbers according to norms of matrix and the expectation and variance of the transformed data. Moreover we give some experimental results about our theoretical expressions by implementing random substitution algorithm.

Experimental and Numerical Study on the Mitigation of High Explosive Blast using Shear Thickening based Shock-Absorbing Materials (전단농화유체기반의 충격완화물질을 이용한 고폭속 폭약의 폭발파 저감에 관한 실험 및 수치해석적 연구)

  • Younghun Ko
    • Explosives and Blasting
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    • v.41 no.3
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    • pp.1-12
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    • 2023
  • A basic assessment of techniques to mitigate the risk of blast shock waves from proximity explosions was conducted. Common existing techniques include using mitigant materials to form barriers around the explosive or in the direction of propagation of the shock wave. Various explosive energy dissipation mechanisms have been proposed, and research on blast shock wave mitigation utilizing impedance differences has drawn considerable interest. In this study, shear thickening fluid (STF) was applied as a blast mitigation material to evaluate the effectiveness of STF mitigation material on explosion shock wave mitigation through explosion experiments and numerical analysis. As a result, the effectiveness of the STF mitigant material in reducing the explosion shock pressure was verified.

A Novel Broadband Channel Estimation Technique Based on Dual-Module QGAN

  • Li Ting;Zhang Jinbiao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.5
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    • pp.1369-1389
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    • 2024
  • In the era of 6G, the rapid increase in communication data volume poses higher demands on traditional channel estimation techniques and those based on deep learning, especially when processing large-scale data as their computational load and real-time performance often fail to meet practical requirements. To overcome this bottleneck, this paper introduces quantum computing techniques, exploring for the first time the application of Quantum Generative Adversarial Networks (QGAN) to broadband channel estimation challenges. Although generative adversarial technology has been applied to channel estimation, obtaining instantaneous channel information remains a significant challenge. To address the issue of instantaneous channel estimation, this paper proposes an innovative QGAN with a dual-module design in the generator. The adversarial loss function and the Mean Squared Error (MSE) loss function are separately applied for the parameter updates of these two modules, facilitating the learning of statistical channel information and the generation of instantaneous channel details. Experimental results demonstrate the efficiency and accuracy of the proposed dual-module QGAN technique in channel estimation on the Pennylane quantum computing simulation platform. This research opens a new direction for physical layer techniques in wireless communication and offers expanded possibilities for the future development of wireless communication technologies.

Grid Discretization Study for the Efficient Aerodynamic Analysis of the Very Light Aircraft (VLA) Configuration

  • Sitio, Moses;Kim, Sangho;Lee, Jaewoo
    • International Journal of Aeronautical and Space Sciences
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    • v.14 no.2
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    • pp.122-132
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    • 2013
  • In this research the development of unstructured grid discretization solution techniques is presented. The purpose is to describe such a conservative discretization scheme applied for experimental validation work. The objective of this paper is to better establish the effects of mesh generation techniques on velocity fields and particle deposition patterns to determine the optimal aerodynamic characteristics. In order to achieve the objective, the mesh surface discretization approaches used the VLA prototype manufacturing tolerance zone of the outer surface. There were 3 schemes for this discretization study implementation. They are solver validation, grid convergence study and surface tolerance study. A solver validation work was implemented for the simple 2D and 3D model to get the optimum solver for the VLA model. A grid convergence study was also conducted with a different growth factor and cell spacing, the amount of mesh can be controlled. With several amount of mesh we can get the converged amount of mesh compared to experimental data. The density around surface model can be calculated by controlling the number of element in every important and sensitive surface area of the model. The solver validation work result provided the optimum solver to employ in the VLA model analysis calculation. The convergence study approach result indicated that the aerodynamic trend characteristic was captured smooth enough compared with the experimental data. During the surface tolerance scheme, it could catch the aerodynamics data of the experiment data. The discretization studies made the validation work more efficient way to achieve the purpose of this paper.

Comparison of various structural damage tracking techniques based on experimental data

  • Huang, Hongwei;Yang, Jann N.;Zhou, Li
    • Smart Structures and Systems
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    • v.6 no.9
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    • pp.1057-1077
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    • 2010
  • An early detection of structural damages is critical for the decision making of repair and replacement maintenance in order to guarantee a specified structural reliability. Consequently, the structural damage detection, based on vibration data measured from the structural health monitoring (SHM) system, has received considerable attention recently. The traditional time-domain analysis techniques, such as the least square estimation (LSE) method and the extended Kalman filter (EKF) approach, require that all the external excitations (inputs) be available, which may not be the case for some SHM systems. Recently, these two approaches have been extended to cover the general case where some of the external excitations (inputs) are not measured, referred to as the adaptive LSE with unknown inputs (ALSE-UI) and the adaptive EKF with unknown inputs (AEKF-UI). Also, new analysis methods, referred to as the adaptive sequential non-linear least-square estimation with unknown inputs and unknown outputs (ASNLSE-UI-UO) and the adaptive quadratic sum-squares error with unknown inputs (AQSSE-UI), have been proposed for the damage tracking of structures when some of the acceleration responses are not measured and the external excitations are not available. In this paper, these newly proposed analysis methods will be compared in terms of accuracy, convergence and efficiency, for damage identification of structures based on experimental data obtained through a series of laboratory tests using a scaled 3-story building model with white noise excitations. The capability of the ALSE-UI, AEKF-UI, ASNLSE-UI-UO and AQSSE-UI approaches in tracking the structural damages will be demonstrated and compared.

Passive 3D motion optical data in shaking table tests of a SRG-reinforced masonry wall

  • De Canio, Gerardo;de Felice, Gianmarco;De Santis, Stefano;Giocoli, Alessandro;Mongelli, Marialuisa;Paolacci, Fabrizio;Roselli, Ivan
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.53-71
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    • 2016
  • Unconventional computer vision and image processing techniques offer significant advantages for experimental applications to shaking table testing, as they allow the overcoming of most typical problems of traditional sensors, such as encumbrance, limitations in the number of devices, range restrictions and risk of damage of the instruments in case of specimen failure. In this study, a 3D motion optical system was applied to analyze shake table tests carried out, up to failure, on a natural-scale masonry structure retrofitted with steel reinforced grout (SRG). The system makes use of wireless passive spherical retro-reflecting markers positioned on several points of the specimen, whose spatial displacements are recorded by near-infrared digital cameras. Analyses in the time domain allowed the monitoring of the deformations of the wall and of crack development through a displacement data processing (DDP) procedure implemented ad hoc. Fundamental frequencies and modal shapes were calculated in the frequency domain through an integrated methodology of experimental/operational modal analysis (EMA/OMA) techniques with 3D finite element analysis (FEA). Meaningful information on the structural response (e.g., displacements, damage development, and dynamic properties) were obtained, profitably integrating the results from conventional measurements. Furthermore, the comparison between 3D motion system and traditional instruments (i.e., displacement transducers and accelerometers) permitted a mutual validation of both experimental data and measurement methods.

Studies on Computer Optimization Techniques for Hydrophilic Vehicle Compositions

  • Lee, Chi-Ho;Shin, Young-Hee
    • Archives of Pharmacal Research
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    • v.11 no.3
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    • pp.185-196
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    • 1988
  • The inflence of hydrophilic vehicles on percutaneous absorption rate of griseofulvin was studied using intact skin of full thickness of hairless rat. The in vitro absorption rates were used as the characteristics for deciding the optimum formula of ointment vehicles. The optimum formula of vehicle compositions for maximum absorption rate was obtained from the polynomial regression equation and the two graphical techniques, contour graph and partial derivative graph. It was composed of sodium lauryl sulfate (1.65 W /W%), white petrolatum (16.5 W /W%), propylene glycol (12.0 W /W%), and stearyl alcohol (19.6W /W%). The experimental value obtained from the optimum formula and the prediction value were 33.99 and 33.87 ${\mu}g/\sqrt{min}$, respectively. From these results, it was believed that optimum formula for semisolid dosage forms could be obtained from the application of the optimization technique used in this study.

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Preventive dentistry for children (소아 예방치과)

  • Kim, Jin Bom
    • Clinical and Experimental Pediatrics
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    • v.51 no.2
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    • pp.129-133
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    • 2008
  • Dental caries is the first disease to cause the pathological extraction of teeth in children. The complete prevention of dental caries is not achieved by toothbrushing alone. The use of fluoride and pit and fissure sealant is regarded as key tools to prevent dental caries. Fluoride-containing tablets or multi-vitamins and community water fluoridation can be used as systemic application techniques. Professional fluoride application, fluoride iontophoresis on teeth, fluoride mouth rinsing and fluoride-containing toothpaste can be used as local application techniques. Pit and fissure sealant is mainly used to prevent dental caries on occlusal surfaces of premolars and molars. Sweeteners not to occur dental caries has been developed to substitute sucrose. Dental erosion increases according to the high consumption of acidic soft drink or beverages. The appropriate use of fluoride and pit and fissure sealant are recommended to prevent dental caries effectively and the education is required to reduce the consumption of acidic soft drinks or beverages to decrease dental erosion.