• Title/Summary/Keyword: Degree of Freedom

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Interaction Design Study of Virtual Reality Safety Education Contents (가상현실 안전교육 콘텐츠의 인터랙션 디자인 연구)

  • Chang, Hyo-Jin;Chang, Sun-Hee
    • The Journal of the Korea Contents Association
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    • v.21 no.9
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    • pp.75-87
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    • 2021
  • The purpose of this study is to derive the characteristics of interaction design for each stage of content composition so that it can be referred to in the planning and production of virtual reality safety education contents. It was confirmed that each of the following interaction design features was found in the three configuration steps: acquisition of situation response procedure knowledge, accident situation experiential learning, and content confirmation and evaluation. First, it was revealed that the quality of experience was controlled by increasing the fidelity of behaviors and reducing general and repetitive behaviors in order to emphasize the educational content-related experiences in the learner experience stage. Second, in order for learners to easily recognize main interaction objects in order to acquire information on safe behavior procedures in unfamiliar environments, use of spatial UI or signifiers using arrows or symbols, posts that specifically instruct actions, and multisensory signals Therefore, it was found to be important to emphasize essential actions in a way that lowers the degree of freedom of user experience, and the proportion of non-realistic interactions for cognitive interactions was found to increase. Lastly, in the confirmation and evaluation stage of the experience, it is important to use the meta UI to alleviate negative experiences such as physical damage after experiencing a safety accident situation,

The Effects of Preferred Job Type of University Students on the Confirmation Bias and Job Anxiety (대학생의 선호직업유형이 확증편향과 취업불안에 미치는 영향)

  • Roh, Seon-Hee;Kim, Ki-Seung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.190-199
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    • 2019
  • This quantitative study analyzed the influence of college students' preferred type of occupation on a confirmation bias and job anxiety during the process of making a career decision. The questionnaires were distributed to university students in Seoul and the metropolitan area for 500 weeks from July 10 2017 to August 8, 2017. Among them, 482 valid samples of data were analyzed by data coding and data cleaning usin SPSS 18.0 statistics and the AMOS 18.0 program. The main results of this study are that the type of business preference for an affirmative bias has a positive (+) direct influence (${\beta}=.374$) and the type of freedom has a positive direct influence (${\beta}=.326$) and a negative direct influence (${\beta}=-.274$). In the case of job anxiety, the influence of job type is more increased. The confirmation bias shows that the business type and freestyle type find cause in effort or achievement motive, while rect type is recognized as social environment and structural problem. In conclusion, there is a difference in the degree of confirmation bias and job insecurity. This study shows that college students' preferred occupation types can help them to understand the bias and anxiety that they have in preparing for the job and help to reduce job anxiety, and these findings are expected to be useful for career guidance.

Evaluation of Human Demonstration Augmented Deep Reinforcement Learning Policy Optimization Methods Using Object Manipulation with an Anthropomorphic Robot Hand (휴먼형 로봇 손의 사물 조작 수행을 이용한 인간 행동 복제 강화학습 정책 최적화 방법 성능 평가)

  • Park, Na Hyeon;Oh, Ji Heon;Ryu, Ga Hyun;Anazco, Edwin Valarezo;Lopez, Patricio Rivera;Won, Da Seul;Jeong, Jin Gyun;Chang, Yun Jung;Kim, Tae-Seong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.11a
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    • pp.858-861
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    • 2020
  • 로봇이 사람과 같이 다양하고 복잡한 사물 조작을 하기 위해서 휴먼형 로봇손의 사물 파지 작업이 필수적이다. 자유도 (Degree of Freedom, DoF)가 높은 휴먼형(anthropomorphic) 로봇손을 학습시키기 위하여 사람 데모(human demonstration)가 결합된 강화학습 최적화 방법이 제안되었다. 본 연구에서는 강화학습 최적화 방법에 사람 데모가 결합된 Demonstration Augmented Natural Policy Gradient(DA-NPG)와 NPG 의 성능 비교를 통하여 행동 복제의 효율성을 확인하고, DA-NPG, DA-Trust Region Policy Optimization (DA-TRPO), DA-Proximal Policy Optimization (DA-PPO)의 최적화 방법의 성능 평가를 위하여 6 종의 물체에 대한 휴먼형 로봇손의 사물 조작 작업을 수행한다. 그 결과, DA-NPG 와 NPG를 비교한 결과를 통해 휴먼형 로봇손의 사물 조작 강화학습에 행동 복제가 효율적임을 증명하였다. 또한, DA-NPG 는 DA-TRPO 와 유사한 성능을 보이면서 모든 물체에 대한 사물 파지에 성공하여 가장 안정적이었다. 반면, DA-TRPO 와 DA-PPO 는 사물 조작에 실패한 물체가 존재하여 불안정한 성능을 보였다. 본 연구에서 제안하는 방법은 향후 실제 휴먼형 로봇에 적용하여 휴먼형 로봇 손의 사물조작 지능 개발에 유용할 것으로 전망된다.

Examining Impact of Weather Factors on Apple Yield (사과생산량에 영향을 미치는 기상요인 분석)

  • Kim, Mi Ri;Kim, Seung Gyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.274-284
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    • 2014
  • Crops and varieties are mostly affected by temperature, the amount of precipitation, and duration of sunshine. This study aims to identify the weather factors that directly influence to apple yield among the series of daily measured weather variables during growing seasons. In order to identify them, 1) a priori natural scientific knowledge with respect to the growth stage of apples and 2) pure statistical approaches to minimize bias due to the subject selection of variables are considered. Each result estimated by the Panel regression using fixed/random effect models is evaluated through suitability (i.e., Akaike information criterion and Bayesian information criterion) and predictability (i.e., mean absolute error, root mean square error, mean absolute percentage). The Panel data of apple yield and weather factors are collected from fifteen major producing areas of apples from 2006 to 2013 in Korea for the case study. The result shows that variable selection using factor analysis, which is one of the statistical approaches applied in the analysis, increases predictability and suitability most. It may imply that all the weather factors are important to predict apple yield if statistical problems, such as multicollinearity and lower degree of freedom due to too many explanatory variables used in the regression, can be controlled effectively. This may be because whole growth stages, such as germination, florescence, fruit setting, fatting, ripening, coloring, and harvesting, are affected by weather.

Comparison of ISO-GUM and Monte Carlo Method for Evaluation of Measurement Uncertainty (몬테카를로 방법과 ISO-GUM 방법의 불확도 평가 결과 비교)

  • Ha, Young-Cheol;Her, Jae-Young;Lee, Seung-Jun;Lee, Kang-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.7
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    • pp.647-656
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    • 2014
  • To supplement the ISO-GUM method for the evaluation of measurement uncertainty, a simulation program using the Monte Carlo method (MCM) was developed, and the MCM and GUM methods were compared. The results are as follows: (1) Even under a non-normal probability distribution of the measurand, MCM provides an accurate coverage interval; (2) Even if a probability distribution that emerged from combining a few non-normal distributions looks as normal, there are cases in which the actual distribution is not normal and the non-normality can be determined by the probability distribution of the combined variance; and (3) If type-A standard uncertainties are involved in the evaluation of measurement uncertainty, GUM generally offers an under-valued coverage interval. However, this problem can be solved by the Bayesian evaluation of type-A standard uncertainty. In this case, the effective degree of freedom for the combined variance is not required in the evaluation of expanded uncertainty, and the appropriate coverage factor for 95% level of confidence was determined to be 1.96.

Design of Vision-based Interaction Tool for 3D Interaction in Desktop Environment (데스크탑 환경에서의 3차원 상호작용을 위한 비전기반 인터랙션 도구의 설계)

  • Choi, Yoo-Joo;Rhee, Seon-Min;You, Hyo-Sun;Roh, Young-Sub
    • The KIPS Transactions:PartB
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    • v.15B no.5
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    • pp.421-434
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    • 2008
  • As computer graphics, virtual reality and augmented reality technologies have been developed, in many application areas based on those techniques, interaction for 3D space is required such as selection and manipulation of an 3D object. In this paper, we propose a framework for a vision-based 3D interaction which enables to simulate functions of an expensive 3D mouse for a desktop environment. The proposed framework includes a specially manufactured interaction device using three-color LEDs. By recognizing position and color of the LED from video sequences, various events of the mouse and 6 DOF interactions are supported. Since the proposed device is more intuitive and easier than an existing 3D mouse which is expensive and requires skilled manipulation, it can be used without additional learning or training. In this paper, we explain methods for making a pointing device using three-color LEDs which is one of the components of the proposed framework, calculating 3D position and orientation of the pointer and analyzing color of the LED from video sequences. We verify accuracy and usefulness of the proposed device by showing a measurement result of an error of the 3D position and orientation.

Effect of the Nonlinearity of the Soft Soil on the Elastic and Inelastic Seismic Response Spectra (연약지반의 비선형성이 탄성 및 비탄성 지진응답스펙트럼에 미치는 영향)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.4 s.44
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    • pp.11-18
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    • 2005
  • Inelastic seismic analysis is necessary for the seismic design due to the nonlinear behavior of a structure-soil system, and the importance of the performance based design considering the soil-structure interaction is recognized for the reasonable seismic design. In this study, elastic and inelastic seismic response analyses of a single degree of freedom system on the soft soil layer were peformed considering the nonlinearity of the soil for the 11 weak or moderate, and 5 strong earthquakes scaled to the nominal peak acceleration of 0.075g, 0.15g, 0.2g and 0.3g. Seismic response analyses for the structure-soil system were peformed in one step applying the earthquake motions to the bedrock In the frequency domain, using a pseudo 3-D dynamic analysis software. Study results indicate that it is necessary to consider the nonlinear soil-structure interaction effects and to perform the performance based seismic design for the various soil layers rather than to follow the routine procedures specified in the seismic design codes. Nonlinearity of the soft soil excited with the weak earthquakes also affected significantly to the elastic and inelastic responses due to the nonlinear soil amplification of the earthquake motions, and it was pronounced especially for the elastic ones.

Effects of Nonlinear Motions due to Abutment-Soil Interaction upon Seismic Responses of Multi-Span Simply Supported Bridges (비선형 교대운동이 교량구조물의 지진응답에 미치는 영향분석)

  • 김상효;마호성;이상우;경규혁
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.6
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    • pp.17-24
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    • 2002
  • Dynamic behaviors of a bridge system with several simple spans are evaluated to examine the effects of nonlinear abutment motions upon the seismic responses of the bridge. The idealized mechanical model for the whole bridge system is developed by adopting the multi-degree-of-freedom system, which can consider various influential components. To compare the results, both linear and nonlinear abutment-backfill models are prepared. The linear system has the constant abutment stiffness, and the nonlinear system has the nonlinear stiffness considering the abutment stiffness degradation due to the abutment-soil interaction. From simulation results, the nonlinear abutment motion is found to have an important influence upon the global bridge motions. Maximum relative distances between adjacent vibration units are found to be larger than those found from the linear system. In particular, maximum relative distances at the location with the highest possibility of unseating failure are increased up to about 30% in the nonlinear system. The effects of nonlinear behavior of an abutment on the bridge seismic behaviors are also increased as the number of span increase. Therefore, it can be concluded that the abutment-soil interaction should be considered in the seismic analysis of the bridge system.

Generation of Floor Response Spectra including Equipment-Structure Interaction in Frequency Domain (진동수 영역에서 기기-구조물 상호작용을 고려한 층응답스펙트럼의 작성)

  • Choi, Dong-Ho;Lee, Sang-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.6 s.46
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    • pp.13-19
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    • 2005
  • Floor response spectra for dynamic response of subsystem such as equipment, or piping in nuclear power plants are usually generated without considering dynamic interaction between main structure and subsystem. This study describes the analytic method in which equipment response spectra can be obtained through dynamic analysis considering equipment-structure Interaction(ESI). In this method, dynamic response of the equipment by this method is based on a dynamic substructure method in which the equipment-structure system is partitioned into the single-degree-ol-freedom system(SDOF) representing the equipment and the equipment support impedance representing the dynamic charactenstics of the structure ai the equipment support. A family of equipment response spectra is developed by applying this method to calculate the maximum responses of a family of SDOF equipment systems with wide banded equipment frequency, damping ratio, and mass. The method is validated by comparing the floor response spectrum from this method with the floor response spectrum generated from the rigorous analysis including equipments on the containment building of a prototypical nuclear power plant. in order to Investigate ESI effect in the response of equipment, response values from the method and the conventional approach without considering ESI are compared for the equipment having the mass less than 1% of the total structural mass. Response spectra from the method showed lower spectral amplitudes than those of the conventional floor response spectra around controlling frequencies.

An Atlas Generation Method with Tiny Blocks Removal for Efficient 3DoF+ Video Coding (효율적인 3DoF+ 비디오 부호화를 위한 작은 블록 제거를 통한 아틀라스 생성 기법)

  • Lim, Sung-Gyun;Kim, Hyun-Ho;Kim, Jae-Gon
    • Journal of Broadcast Engineering
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    • v.25 no.5
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    • pp.665-671
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    • 2020
  • MPEG-I is actively working on standardization on the coding of immersive video which provides up to 6 degree of freedom (6DoF) in terms of viewpoint. 3DoF+ video, which provides motion parallax to omnidirectional view of 360 video, renders a view at any desired viewpoint using multiple view videos acquisitioned in a limited 3D space covered with upper body motion at a fixed position. The MPEG-I visual group is developing a test model called TMIV (Test Model for Immersive Video) in the process of development of the standard for 3DoF+ video coding. In the TMIV, the redundancy between a set of input view videos is removed, and several atlases are generated by packing patches including the remaining texture and depth regions into frames as compact as possible, and coded. This paper presents an atlas generation method that removes small-sized blocks in the atlas for more efficient 3DoF+ video coding. The proposed method shows a performance improvement of BD-rate bit savings of 0.7% and 1.4%, respectively, in natural and graphic sequences compared to TMIV.