• Title/Summary/Keyword: Relative convergence

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Comparison of Relative Accommodation, Accommodative Facility, and Addition Based on Occupation of Initial Presbyopia (직업에 따른 초기 노안의 상대조절력, 조절용이성, 가입도 비교)

  • Kim, Hyun-Mok;Son, Jeong-Sik;Lee, Won-Jin;Lee, Jae Yoon;Cho, Hyun Gug
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.4
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    • pp.59-63
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    • 2009
  • Purpose: This study was designed to compare the relative accommodation, the accommodative facility, and the addition whose 40's initial presbyopia divided into five occupations (driver, official worker, housewife, field worker, teacher). Methods: We measured the values of near point convergence (NPC), positive relative accommodation (PRA), negative relative accommodation (NRA), accommodative facility, and addition. Results: Official worker group had lower PRA, higher NRA, and lower accommodative facility compared with them of the other groups. The average of addition was as follows: official worker > driver > field worker > housewife > teacher. Conclusions: Because the difference of working environment based on occupation affects the accommodative functions and addition, it is important to consider the patient's occupation when opticians measure the addition for near vision of initial presbyopia.

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A Study on the Strength and Stiffness of Multi-Stage Cubic Truss Unit Structures (복합 입체형 정육면체 트러스 단위구조체의 강도 및 강성에 대한 해석 연구)

  • Choi, Jeongho
    • Journal of the Korea Convergence Society
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    • v.10 no.4
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    • pp.139-145
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    • 2019
  • This paper investigated the strength and stiffness of composite truss unit structures. The model used is a core-filled model combining the Kagome model and the cube truss model. The material properties used for the analysis are 304 stainless steel with elastic modulus of 193 GPa and yield stress of 215 MPa. The theoretical equation is derived from the relative elasticity relation of Gibson - Ashby ratio, the analysis was performed using Deform 3D, a commercial tool. In conclusion, the relative elasticity for this unit model correlates with 1.25 times the relative density and constant coefficient, elasticity is inversely proportional to pore size. The relative compressive strength has a correlation with relative density of 1.25 times. Proof of this is a real experiment, the derived theoretical relationship should further consider mechanical behavior such as bending and buckling. In the future, it is hoped that the research on the elasticity and the stress according to the structure of the three-dimensional space will be continued.

The study of binocular function of college students (대학생들의 시기능에 대한 연구)

  • Cho, Young-Rae;Park, Hyun-Ju;Seo, Ji-Keun;Seong, Jeong-Sub;Kim, Jae-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.10 no.2
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    • pp.103-110
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    • 2005
  • Binocular vision had a short history in Korea. As there were many near works in these days, the needs about comparative study have been increased. There was related to both refractive error and binocular anomalies, but it is difficult to applying for binocular vision expected findings in itself due to the fact that Korean differ from foreigner. Objects were 100 adults in 18-36 years old ages, The test was Von Gaefe method and used aparatus was phoropter(Shinnippon VT10)and visual chart(Shinnippon CT30). According to interview results was that symptom in near works were headaches 28.0%, blinking 27.3%, red eye 25.1%, eyepain 15.6%, watering 15.3%, itch 12.2%, photophobia 8.5% and eye strain 7.4%. A people who have above ${\pm}0.50$ D refractive error in total objectives (100-male 45/female 55) were classified into ametropia. There was a results such as emmetropia (12.0%), ametropia(88.0%), exophoria(32.0%), esophoria(12.0%). Far negative relative convergence were that in case of high 43.0%, in case of low 7.0%. Far positive relative convergence were that in case of high 15.0%, in case of low 38.0%. Near phoria was exophoria(32.0%), esophoria(12.0%). Near negative relative convergence were that in case of high 23.0%, in case of low 38.0%. Far positive relative convergence were that in case of high 29.0%, in case of low 23.0%. Near negative relative accommodation were that in case of high 10.0%, in case of low 14,0%, Far positive relative convergence were that in case of high 69.0%, in case of low 12.0%. Results were different from expected findings, and especially positive relative accommodation was very high, However, We suggest that the expected findings in Korea for several subjects must study in binocular function.

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The prediction of vapor-liquid equilibrium data for 2-methyl-2-propanol-2-butanone system at low pressure (저압하에서 2-methyl-2-propanol-2-butanone계의 기액평형치의 추산)

  • Shim, Hong-Seub;Rhew, Jong-Ha
    • Journal of the Korean Society of Industry Convergence
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    • v.7 no.1
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    • pp.97-105
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    • 2004
  • The Vapor-liquid equilibrium data for the binary system of 2-methyl-2-propanol-2-butanone are measured at subatmospheric pressure of 100, 200, 300, 400, 500, 600, 700 and 760 torr. This study shows that the relations between logarithmic values of relative valatility(log ${\alpha}$)and liquid phase composition(${\chi}$) in the above binary systems are expressed as a linear function. When the linear relationships of between logarithmic values of relative volatilities and liquid phase compositions in the binary systems of various pressure intersect at a point, this empirical equation can be applied to the systems of this kind. From these relations the vapor-liquid equilibrium data are estimated and compared with the measured values to be in a good agreement with in accuracy ${\pm}0.0021$ for the various pressure.

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Parking Space Detection based on Camera and LIDAR Sensor Fusion (카메라와 라이다 센서 융합에 기반한 개선된 주차 공간 검출 시스템)

  • Park, Kyujin;Im, Gyubeom;Kim, Minsung;Park, Jaeheung
    • The Journal of Korea Robotics Society
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    • v.14 no.3
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    • pp.170-178
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    • 2019
  • This paper proposes a parking space detection method for autonomous parking by using the Around View Monitor (AVM) image and Light Detection and Ranging (LIDAR) sensor fusion. This method consists of removing obstacles except for the parking line, detecting the parking line, and template matching method to detect the parking space location information in the parking lot. In order to remove the obstacles, we correct and converge LIDAR information considering the distortion phenomenon in AVM image. Based on the assumption that the obstacles are removed, the line filter that reflects the thickness of the parking line and the improved radon transformation are applied to detect the parking line clearly. The parking space location information is detected by applying template matching with the modified parking space template and the detected parking lines are used to return location information of parking space. Finally, we propose a novel parking space detection system that returns relative distance and relative angle from the current vehicle to the parking space.

Effect of skeletal muscle of adolescents on physical strength, physique, and motor coordination

  • KIM, Jun-Su;LEE, Tae-Gyung;KIM, Young-Chul
    • The Korean Journal of Food & Health Convergence
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    • v.8 no.2
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    • pp.15-27
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    • 2022
  • This study aims to analyze the relative importance of bone age and chronological age in physique according to gender and to identify the relative importance of bone age, chronological age, and physique in physical fitness and motor coordination according to gender in order to alleviate the imbalance between physique and physical fitness in children. A total of 666 children(346 males, 320 females) between the ages of 11-14 were enrolled as subjects, and the skeletal maturation The skeletal maturation were measured by taking hand-wrist. Physical fitness were measured through a total of 4 components: muscular strength. The results of this study. First, physique variables for both males and females aged 11-14 were found to be more significant predictors of bone age than chronological age. Second, for physical fitness in males, in the order of %fat, body water, waist-hip ratio, weight, fat-free mass, and chronological age were more significant predictor variables; and in females, in the order of %fat, fat-free mass, height, chronological age, weight, bone age, fat mass, and body water were more significant predictor variables. For bone age and chronological age in physical fitness, bone age in males and chronological age in females found to be the more representative variables respectively.

Numerical Study on Improvement of Storage Environment of Igloo-Shaped Magazine Using Forced Ventilation (강제환기를 적용한 이글루형 탄약고 저장환경 개선에 관한 수치적 연구)

  • Yoon, Hae-Deun;Kim, Seong Hoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.1
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    • pp.99-106
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    • 2021
  • This study explores the improvement of storage environment of igloo-shaped magazine using forced ventilation. Conjugate heat transfer analysis of forced convection and conduction are performed to calculate the flow, temperature, and relative humidity field in igloo-shaped magazine. Through the conjugate heat transfer analysis, the effects of inlet vent, volume flow rates of jet, and jet angles on the condensation and relative humidity are numerically investigated. The area of condensation in igloo-shaped magazine and relative humidity at the surface of ammunitions are then calculated.

Structural Convergence Improvement Schemes on Adaptive Control Redesigning a Lyapunov's Function (Lyapunov 함수를 재설계한 적응제어외의 구조적 수렴향상 방법에 대한 연구)

  • Kang, Hoon
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.1
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    • pp.1-9
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    • 1989
  • The convergence analysis of adavtive control schemes has been studied over the past decades, but the importance of structure to fast conversgece of adaptive control systems is still a controversial issue. This paper deals with the relative improvement of the exponential rate of convergence in adaptive error models. The Lyapunov's direct method is applied to adaptive control systems in order to improve the convergence rate by modifying the feedback structure of the error systems. Some simulation examples are illustrated to show fast convergence and robustness of these schemes.

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Highly Efficient Video Codec for Entertainment-Quality

  • Jeong, Se-Yoon;Lim, Sung-Chang;Lee, Ha-Hyun;Kim, Jong-Ho;Choi, Jin-Soo;Choi, Hae-Chul
    • ETRI Journal
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    • v.33 no.2
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    • pp.145-154
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    • 2011
  • We present a novel video codec for supporting entertainment-quality video. It has new coding tools such as an intra prediction with offset, integer sine transform, and enhanced block-based adaptive loop filter. These tools are used adaptively in the processing of intra prediction, transform, and loop filtering. In our experiments, the proposed codec achieved an average reduction of 13.35% in BD-rate relative to H.264/AVC for 720p sequences.

Convergence rates of the TE EFIE scattering solutions from a PEC cylinder (PEC 원통을 TE EFIE 방법으로 산란 해석한 결과의 수렴율)

  • Hong, Chinsoo;Bae, HyungChul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.7189-7195
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    • 2015
  • The method of moments (MoM) is implemented to simulate scattering from a PEC (perfectly electric conductor) cylinder in the TE(transversw electric) EFIE (Electric Field Integral Equation) approach. The procedure expresses the singularity integral and the hypersingularity integral in terms of an analytic function and employs a singularity isolation process coupled with numerical technique along the discretized segment to evaluate the self terms. It is known that, in the MoM technique, the choice of base functions and test functions is very important for the accuracy and convergence of the numerical analysis. Thus, in this paper, three conditions, obtained from the combination of basis functions and test functions, are adopted to get the induced currents on the PEC surface. These currents are compared to the analytical one in the relative rms current error to get the condition that shows fast convergence rate. The fast order of convergence of the current error, 2.528, is obtained under the combination of pulse basis function/delta test function.