• Title/Summary/Keyword: Variable-focus

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Development of 3D scanner using structured light module based on variable focus lens

  • Kim, Kyu-Ha;Lee, Sang-Hyun
    • International Journal of Advanced Culture Technology
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    • v.8 no.3
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    • pp.260-268
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    • 2020
  • Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

New Gel-type Biomimetic Variable-focus Lens System (새로운 겔형 생체모방 가변초점 렌즈 시스템)

  • Seo, Jeong-Ho;Son, Hyung-Min;Lee, Yun-Jung
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.11
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    • pp.1082-1088
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    • 2010
  • In this paper, we propose a new gel-type biomimetic variable-focus lens system. The miniaturization of conventional lens system is limited due to the use of a set of glass lenses for adjusting the focal length. Biologically inspired by the focus adjustment mechanism of the human eye, a gel-type single lens system with variable-focus is presented. The proposed system consists of a gel-type lens, mechanical parts such as body, rotation ring, and winding-type SMA actuator. In addition, the proposed system is designed to operate with a simple and miniaturized mechanical structure using a new attachment and driving mechanism. The focusing performance of the proposed system is verified through a series of experiments and measurements of the shape of the lens using tomography.

Contrastive Focus and Variable Case Marking: A Comparison between Subjects and Objects

  • Lee, Han-Jung
    • Language and Information
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    • v.13 no.2
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    • pp.1-27
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    • 2009
  • This paper examines the (a)symmetries in the realization of focused subjects and objects in Korean. Through rating experiments, we demonstrate that native speakers' judgments of acceptability of sentences containing case-marked or case-ellipsed subjects and objects are sensitive to the contrastiveness strength and the discourse accessibility of focused arguments. However, our experiments also show that focused subjects exhibit stronger preference for explicit case marking over case ellipsis and that contrastiveness strength and discourse accessibility have weaker influence on the case marking and ellipsis of focused subjects compared to focused objects. We propose an account of variable case marking that is capable of subsuming both the similarities and differences between focused subjects and objects under the universal theory of markedness. In particular, it is shown that the similarities between focused subjects and objects are predicted by the proposed account based on the contrastiveness strength and the discourse accessibility of focused arguments and that the differences between focused subjects and objects follow naturally from the relative markedness of focus as subjects.

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Robust Variable Selection in Classification Tree

  • Jang Jeong Yee;Jeong Kwang Mo
    • Proceedings of the Korean Statistical Society Conference
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    • 2001.11a
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    • pp.89-94
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    • 2001
  • In this study we focus on variable selection in decision tree growing structure. Some of the splitting rules and variable selection algorithms are discussed. We propose a competitive variable selection method based on Kruskal-Wallis test, which is a nonparametric version of ANOVA F-test. Through a Monte Carlo study we note that CART has serious bias in variable selection towards categorical variables having many values, and also QUEST using F-test is not so powerful to select informative variables under heavy tailed distributions.

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A Study on the Effect of the Security Guard Emotional Disharmony to Job Performance (경비원 감정부조화가 직무성과에 미치는 영향)

  • Kim, Tae-Hyun;Ryu, Seong-Min
    • Asia-Pacific Journal of Business
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    • v.10 no.3
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    • pp.125-142
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    • 2019
  • The study wanted to verify the effect of emotional sub-compression, a negative variable of emotional labor, on job performance, on security personnel working at private security companies, and further to verify how the impact on emotional sub-compression can affect job performance through the first draft of regulation. Empirical analysis through the study model showed that emotional edema was not a significant effect, but a negative effect on job performance, and that it did not affect the control focus itself. This revealed that emotional harmony has been shown to have a negative impact on performance due to the present state and conflicting situations in one's emotions, which means that emotional harmony does not affect negative or positive effects depending on a person's attributes. It also showed that the temperamental control focus on job performance had a positive impact on employees with an improvement focus and had a negative impact on employees with a preventive focus, and that a temperamental control focus between emotional dissonance and job performance had an effect. This indicated that job performance was affected by a temperamental control focus and that employees with an improvement focus had a positive effect and had a positive effect on performance. The implications of the study in this study are that it can have target differentiation in the areas where the study was conducted on guard workers, a social issue related to the study of emotional labor, and it can be meaningful that the study of emotional labor had a control focus and measured both positive and negative tendencies. It is also believed that there will be contributions to the verification of differences in performance resulting from employee propensity and by linking it with a variable called emotional instability. However, the data collected have the limitations of the subject and region, and the emphasis on cross-sectional analysis and the representative of the various emotions to verify the negative effects of emotional labor, and the problem of securing reliability related to the adjustment focus verification are the limitations of the research.

Optimal Shape Design of Dielectric Micro Lens Using FDTD and Topology Optimization

  • Chung, Young-Seek;Lee, Byung-Je;Kim, Sung-Chul
    • Journal of the Optical Society of Korea
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    • v.13 no.2
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    • pp.286-293
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    • 2009
  • In this paper, we present an optimal shape design method for a dielectric microlens which is used to focus an incoming infrared plane wave in wideband, by exploiting the finite difference time domain (FDTD) technique and the topology optimization technique. Topology optimization is a scheme to search an optimal shape by adjusting the material properties, which are design variables, within the design space. And by introducing the adjoint variable method, we can effectively calculate a derivative of the objective function with respect to the design variable. To verify the proposed method, a shape design problem of a dielectric microlens is tested when illuminated by a transverse electric (TE)-polarized infrared plane wave. In this problem, the design variable is the dielectric constant within the design space of a dielectric microlens. The design objective is to maximally focus the incoming magnetic field at a specific point in wideband.

Focus Types and Gradients in Korean Case Ellipsis

  • Lee, Han-Jung
    • Language and Information
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    • v.12 no.2
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    • pp.1-20
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    • 2008
  • This paper examines the effects of focus types on case ellipsis in Korean. A number of previous studies have suggested that accusative case markers in Korean and Japanese cannot be dropped when the object they mark is contrastively focused (Masunaga, 1988; Yatabe, 1999; Ko, 2000; Lee, 2002). Using experimental evidence, we argue against the view that case ellipsis in Korean is sensitive to the distinction between contrastive vs. non-contrastive focus. An alternative analysis is proposed which accounts for the phenomenon of variable case marking in terms of the interaction between the contrastive strength and the discourse accessibility of focused object NPs. By viewing patterns of case ellipsis as the result of balancing between these two forces, such an analysis can correctly predict the gradient pattern of case ellipsis shown by the three types of focused objects tested in the experiment (contrastive replacing focus, contrastive selecting focus and non-contrastive, informational focus), while at the same time offering an explanation for why subtypes of focus exert distinct influences on case ellipsis.

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Effects of Different Types of Attentional Focus on Dart Throwing Mechanics (주의 집중 방법이 다트 던지기 역학에 미치는 영향)

  • Kim, Hye-Ree;Kong, Se-Jin;Kim, Soo-Yeon;Lee, Ki-Kwang
    • Korean Journal of Applied Biomechanics
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    • v.23 no.4
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    • pp.327-333
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    • 2013
  • The purpose of this study was to investigate the effects of different types of attentional focus(internal focus vs. external focus) on the dart throwing mechanics. Seven expert dart throwing athletes were assigned to an internal focus group and other seven athletes were assigned to an external focus group. Each group was asked to throw dart either under verbal instruction or without instruction. During dart throwing, accuracy(radial error), consistency(bivariate variable error), dart velocity, acceleration, elbow joint ROM, elbow joint angular velocity, EMD(electromechanical delay), iEMG of biceps brachii and triceps brachii, and CI(coactivation index) were collected and analyzed. Nither instruction type nor instruction itself affected in accuracy and consistency. However, in dart velocity and acceleration, there was an interaction between instruction and attentional focus types. Velocity and acceleration increased in the internal condition, where as they decreased in the external condition. The ROM of elbow joint did not affected by instruction and attention type. However, similar to dart velocity and acceleration, angular velocity increased in internal focus group, while it decreased in external focus group. EMG showed no difference with any condition. In conclusion, internal focus is better than external focus for dart throwing.

Analysis of the Heuristic Theory and the Prospect Theory for Smartphones: Focusing on Framing, Endowment Effect and Regulatory Focus Theory (스마트폰을 대상으로 한 휴리스틱 및 프로스펙트 효과 분석: 프레이밍, 보유효과 및 조절초점 이론을 중심으로)

  • Kim, Soon-Hong
    • Journal of Distribution Science
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    • v.14 no.12
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    • pp.99-105
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    • 2016
  • Purpose - In the present study, it has become the most important necessity in our daily lives that consumers' psychological factors affect the use of smartphones, and it has been analyzed through behavioral economic approaches. In this respect, the present study is intended to apply the heuristic theory and the prospect theory among behavioral economics theories to examine how psychological factors affect consumers' product selection. Research design, data, and methodology - In the present study, using smartphone repurchase as a dependent variable, whether regulatory focus effects have interaction effects on behavioral economic theories and behavioral economic effects such as possession (ownership) effects, framing effects, and brand recollection. As an analysis method, questionnaire surveys conducted with university students in Incheon were examined through Two-Way ANOVAs using the SPSS23 package. Results - The analysis from the results are as follows. Using smartphone repurchase as a dependent variable, the main effects and interaction effects on two variables; satisfaction difference with product functions and positive framing variable were statistically significant. Using repurchase as a dependent variable was statistically significant, there was no interaction effect between the two variables; satisfaction difference with product functions and the difference of brands in possession. Using smartphone repurchase as a dependent variable, interaction effects on two variables; satisfaction difference with product functions and the lengths of product possession periods were not statistically significant. The results from the analyses of interaction effects of brand recollection and brands type were statistically significant in possession using repurchase as a dependent variable. The results from the analyses of the main effect of the brands type were statistically significant in possession using repurchase as a dependent variable. Conclusions - The implication of the present study is that it suggests the factors that became important for customers' smartphone purchase following the change in the meaning of smartphones from practical products in the past to hedonic products. Limitations of the present study are first, the study subjects are limited to students and the number of copies in questionnaires is only approximately 130, which is insufficient, so that the present study is not sufficient as a study for entire smartphone users.

A Study on the Effects of Perceived Parenting Attitudes on Regulatory Focus Among College Students: Mediating the Effects of Ego-Resiliency (대학생이 지각한 부모양육태도가 조절초점에 미치는 영향: 자아탄력성의 매개효과)

  • Cho, Gyeong Suk
    • Korean Journal of Child Studies
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    • v.37 no.5
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    • pp.19-31
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    • 2016
  • Objective: The purpose of this study was to test the mediating effects of ego-resilience on relationship between perceived parenting attitudes and regulatory focus among college students. Methods: In this study, 256 college students were surveyed. The collected data were put through correlation analysis using PASW Statistics 18.0. In addition, 3-stage multiple regression analyses and the Sobel test were used to test any mediating effects. Results: The findings show that the diversity of concerns and interests, emotion control, and positive future orientation, the subfactors of ego-resiliency, all have partial mediating effects on the relationship between father's care and promotion focus. Only positive future orientation had partial mediating effects on the relationship between mother's care and promotion focus. Conclusion: Father's care turned out to be an independent variable to explain better the mediating effects of ego-resiliency on relations between parenting attitudes and regulatory focus, which implies the influence and importance of father's care on college students.