• Title/Summary/Keyword: stiff

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Improvement of Track Tracking Performance Using Deep Learning-based LSTM Model (딥러닝 기반 LSTM 모형을 이용한 항적 추적성능 향상에 관한 연구)

  • Hwang, Jin-Ha;Lee, Jong-Min
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.05a
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    • pp.189-192
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    • 2021
  • This study applies a deep learning-based long short-term memory(LSTM) model to track tracking technology. In the case of existing track tracking technology, the weight of constant velocity, constant acceleration, stiff turn, and circular(3D) flight is automatically changed when tracking track in real time using LMIPDA based on Kalman filter according to flight characteristics of an aircraft such as constant velocity, constant acceleration, stiff turn, and circular(3D) flight. In this process, it is necessary to improve performance of changing flight characteristic weight, because changing flight characteristics such as stiff turn flight during constant velocity flight could incur the loss of track and decreasing of the tracking performance. This study is for improving track tracking performance by predicting the change of flight characteristics in advance and changing flight characteristic weigh rapidly. To get this result, this study makes deep learning-based Long Short-Term Memory(LSTM) model study the plot and target of simulator applied with radar error model, and compares the flight tracking results of using Kalman filter with those of deep learning-based Long Short-Term memory(LSTM) model.

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The Open Surgical Treatment for Stiff Elbow (주관절 구축의 관혈적 치료)

  • Lee, Ji-Ho;Ra, In-Hoo;Jeon, In-Ho
    • Clinics in Shoulder and Elbow
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    • v.13 no.2
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    • pp.293-298
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    • 2010
  • Purpose: Since an injured elbow joint can disturb the activity of daily life by limiting motion, especially if the motion is restricted over 40 degree of flexion contracture and under 105 degree of further flexion, it is imperative to select the best method and the timing of treatment of the elbow stiffness. Therefore this review will discuss open surgical techniques for stiff elbows based on the literature. Materials and Methods: It is important to take sufficient clinical examination of the patient, including history taking. And, a surgeon should select appropriate procedure after accurately understanding about the status and cause of the stiff elbow with radiographic methods. Surgical methods include arthroscopic release open release, distraction arthroplasty, total elbow replacement and there are four approachs in the open release - anterior approach, medial "over the top" approach, limited lateral approach: column procedure, posterior extensile approach-. Results and Conclusion: Although at present the arthroscopic technique is emphasized for the treatment of elbow stiffness, a surgeon should know conventional open techniques.

Pathophysiology of Stiff Elbow (주관절 강직의 병태 생리)

  • Song, Hyun-Seok;Yoon, Hyung-Moon
    • Clinics in Shoulder and Elbow
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    • v.13 no.2
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    • pp.286-292
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    • 2010
  • Purpose: Stability of joints and maintenance of range of motion are needed for optimum function. The most common complaint about the elbow joint is joint stiffness. Recent articles have reported good outcomes in the treatment of stiff elbow joints. However, deciding which procedure to use is always difficult. Materials and Methods: Morrey et al. reported that the functional range of motion of the elbow joint is $30-130^{\circ}$ of flexion-extension and $50^{\circ}C$ of supination and pronation. About 90% of daily activities are done using this range of motion. Stiff elbow joints can be classified according to the traumatic events that caused the problem or the location of the main pathology. Intraarticular pathology includes severe articular mismatch, intraarticular adhesions, loss of articular cartilage, mechanical blockade by osteophytes, loose bodies, and hypertrophied synovium. Extraarticular pathology includes severe capsular adhesion due to the trauma or to dislocation, contracture of the collateral ligaments or muscles, bony bridge. Results and Conclusions: The main pathology underlying the loss of extension is the fibrous contracture of the anterior capsule. In this pathology, an anterior capsulectomy would be helpful. The main pathology underlying the loss of flexion is the contracture of the posterior band of medial collateral ligament.

A study on the properties of commercial nonwoven fabrics (시판 부직포의 물성에 관한 연구)

  • Soon Song Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.11 no.1
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    • pp.79-85
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    • 1987
  • The purpose of this study was to help the consumer about the care of nonwoven fabrics by investigation of the properties such as launderability. shrinkage, color fastness and strenth. Materials used were two types, soft and stiff, of commercial nonwoven fabrics. Deter-gents used were neutral detergents, synthetic detergents and dry cleaning solutions(perch-toro-ethylene) The results of this study were summerized as follows; 1. Laundering of nonwoven fabrics in low temperature is more ideal as morphological changes by laundering in high temperature were more prominent than that in low temperature. 2. Ironing of nonwoven fabrics wants more attention on environmental temperature as the rate of shrinkage in high temperature was higher than that in low temperature. Neutral detergents are more desirable as the rate of shrinkage of nonwoven fabrics by laundering with synthetic detergents was more prominent than that with neutral deter-gents. The rate of shringkage of nonwoven fabrics was not affected by dry cleanining. 3. Special care is wanted in order to prevent color transfer from non woven fabrics to polyester or wool during dry cleaning or laundering as the color fastness test show that color changes of nonwoven fabrics were not affected, but that color stain was increased on polyester or wool. 4. The strength was affected by composition of fibers and types of nonwoven fabrics, soft or stiff.

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Efficient Analysis of Building Structures with a Rigid Floor System (주상복합건물의 효율적인 지진해석)

  • 황현식;이동근
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.1
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    • pp.79-88
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    • 1997
  • Very stiff floor system in a residential-commercial building causes some problems in the numerical analysis procedure due to significant difference in stiffness with adjacent elements. Static analysis of structure with a stiff transfer-floor can be performed approximately in two steps for upper and lower parts for the structure. However, it is impossible to perform dynamic analysis in two steps with separate models. An efficient method for dynamic analysis of a structure with a right floor system is proposd in this study. The matrix condensation technique is employed to reduce the degree of freedom for upper and lower parts of the structure and a beam elements with rigid bodies at both ends are introduce to model the rigid floor system. Efficiency and accuracy of the proposed method are verified through analysis of several example structures.

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Ratio of Torsion (ROT): An index for assessing the global induced torsion in plan irregular buildings

  • Stathi, Chrysanthi G.;Bakas, Nikolaos P.;Lagaros, Nikos D.;Papadrakakis, Manolis
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.145-171
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    • 2015
  • Due to earthquakes, many structures suffered extensive damages that were attributed to the torsional effect caused by mass, stiffness or strength eccentricity. Due to this type of asymmetry torsional moments are generated that are imposed by means of additional shear forces developed at the vertical resisting structural elements of the buildings. Although the torsional effect on the response of reinforced concrete buildings was the subject of extensive research over the last decades, a quantitative index measuring the amplification of the shear forces developed at the vertical resisting elements due to lateral-torsional coupling valid for both elastic and elastoplastic response states is still missing. In this study a reliable index capable of assessing the torsional effect is proposed. The performance of the proposed index is evaluated and its correlation with structural response quantities like displacements, interstorey drift, base torque, shear forces and upper diaphragm's rotation is presented. Torsionally stiff, mass eccentric single-story and multistory structures, subjected to bidirectional excitation, are considered and nonlinear dynamic analyses are performed using natural records selected for three hazard levels. It was found that the proposed index provides reliable prediction of the magnitude of torsional effect for all test examples considered.

The effect of structural variability and local site conditions on building fragility functions

  • Sisi, Aida Azari;Erberik, Murat A.;Askan, Aysegul
    • Earthquakes and Structures
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    • v.14 no.4
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    • pp.285-295
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    • 2018
  • In this study, the effect of local site conditions (site class and site amplifications) and structural variability are investigated on fragility functions of typical building structures. The study area is chosen as Eastern Turkey. The fragility functions are developed using site-specific uniform hazard spectrum (UHS). The site-specific UHS is obtained based on simulated ground motions. The implementation of ground motion simulation into seismic hazard assessment has the advantage of investigating detailed local site effects. The typical residential buildings in Erzincan are represented by equivalent single degree of freedom systems (ESDOFs). Predictive equations are accomplished for structural seismic demands of ESDOFs to derive fragility functions in a straightforward manner. To study the sensitivity of fragility curves to site class, two sites on soft and stiff soil are taken into account. Two alternative site amplification functions known as generic and theoretical site amplifications are examined for these two sites. The reinforced concrete frames located on soft soil display larger fragilities than those on stiff soil. Theoretical site amplification mostly leads to larger fragilities than generic site amplification more evidently for reinforced concrete buildings. Additionally, structural variability of ESDOFs is generally observed to increase the fragility especially for rigid structural models.

Simulation of a Diffusion Flame in Turbulent Mixing Layer by the Flame Hole Dynamics Model with Level-Set Method (Level-Set 방법이 적용된 Flame Hole Dynamics 모델을 통한 난류 혼합층 확산화염 모사)

  • Kim, Jun-Hong;Chung, S.H.;Ahn, K.Y.;Kim, J.S.
    • 한국연소학회:학술대회논문집
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    • 2004.06a
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    • pp.102-111
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    • 2004
  • Partial quenching structure of turbulent diffusion flames in a turbulent mixing layer is investigated by the method of flame hole dynamics to develope a prediction model for the turbulent lift off. The present study is specifically aimed to remedy the problem of the stiff transition of the conditioned partial burning probability across the crossover condition by adopting level-set method which describes propagating or retreating flame front with specified propagation speed. In light of the level-set simulations with two model problems for the propagation speed, the stabilizing conditions for a turbulent lifted flame are suggested. The flame hole dynamics combined with level-set method yields a temporally evolving turbulent extinction process and its partial quenching characteristics is compared with the results of the previous model employing the flame-hole random walk mapping. The probability to encounter reacting' state, conditioned with scalar dissipation rate, demonstrated that the conditional probability has a rather gradual transition across the crossover scalar dissipation rate in contrast to the stiff transition of resulted from the flame-hole random walk mapping and could be attributed to the finite response of the flame edge propagation.

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