• Title/Summary/Keyword: Three way measurement

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Analysis of Stability on Single-leg Standing by Wearing a Head Mounted Display

  • Woo, Byung Hoon
    • Korean Journal of Applied Biomechanics
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    • v.27 no.2
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    • pp.149-155
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    • 2017
  • Objective: The purpose of this study was to investigate the effects of three visual conditions (eyes opened, eyes closed, and wearing of a head mounted display [HMD]) on single-leg standing through kinematics and kinetic analysis. Method: Twelve college students (age: $24.5{\pm}2.6years$, height: $175.0{\pm}6.4cm$, weight: $69.2{\pm}5.1kg$) participated in this study. The study method adopted three-dimensional analysis with six cameras and ground reaction force measurement with one force plate. The analysis variables were coefficient of variation (CV) of the center of body mass, head movement, ground reaction force, and center of pressure, which were analyzed using one-way analysis of variance with repeated measures according to visual conditions. Results: In most cases, the results of this study showed that the CV was significantly higher in the order of HMD wearing, eyes closed, and eyes opened conditions. Conclusion: Our results indicated that body sway was the largest in the HMD wearing condition, and the risk of falling was high owing to the low stability.

Visualization of Ocean Environments through VRML (VRML을 이용한 해역환경 가시화 연구)

  • Kim, Jong-Kyu;Park, Sang-Woo;Kim, Jong-Hwa
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.3
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    • pp.427-433
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    • 2005
  • The study of Web GUI(Graphic User Information) system for Virtual Reality System is mainly performed on effective methodology which transform real world data to computing world data. MGIS(Marine Geographic Information System) has its own target on reliable data service by acquisition of geometric information using accurate measurement and graphical visualization. This type of raw data visualization can be built without software tools, yet is incredibly useful for interpreting and communicating data. Even simple visualizations can aid in the interpretation of complex 3D relationships that are frequently encountered in the geosciences. The Virtual Reality Modeling Language provides an easy way for geoscientists to construct complex visualizations that can be viewed with free software. This study propose a three dimensional Web GUI system using MGIS-based three dimensional data models and virtual imaging system. Finally, we design a Web GUI system integrating above data models.

Comparative Study of Radiation Exposure using Entrance Skin Dose Calculation Technique in Diagnostic X-Ray Radiography (입사 표면 선량 계산에 따른 진단용 X-선 촬영시 피폭선량 비교 연구)

  • Han, Jae-Bok;Choi, Nam-Gil;Sung, Ho-Jin
    • The Journal of the Korea Contents Association
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    • v.11 no.12
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    • pp.357-363
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    • 2011
  • The aim of this study is to compare radiation dose in diagnostic X-ray radiography and calculated by different mathematical equation. The result of ESDs direct measurement and that calculated by Mori NDD-M shows the biggest difference. On the other hand, equation by Edmonds shows the lowest difference of ESDs. Also, Rectification due to the difference between direct dose measurement and calculation method commutated three-phase, single phase and inverter type, show less difference in the drive way. In conclusion, this study can be helpful for expecting radiation dose-exposure and control exposure parameters for the diagnostic x-ray radiography.

The Measurement Model for the Evaluation of Information Systems Service : The Case of Chinese SI Company (정보시스템 서비스 평가를 위한 측정모형의 개발 및 실증적 검증 : 중국 SI 기업 사례)

  • Lee, Sang-Jae;Lim, Gyoo-Gun
    • Journal of Information Technology Services
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    • v.10 no.2
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    • pp.141-162
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    • 2011
  • The controls of Information Systems (IS) have been an more critical issue controls as the sophistication and integration of IS is more proceeded. ITGI (The Information Technology Governance Institute) of ISACA (Information Systems Audit and Control Association) has suggested COBIT (Control Objectives for Information and related Technology) and this has been widely recognized the evaluation model of IS controls. In COBIT, IS was evaluated in terms of process, information quality, and IT resources. This study used COBIT in order to suggest and empirically test an evaluation model of IS service. The data was collated from one major Chinese SI (Systems Integration) company in four domains of processes : planning and organization, acquisition and implementation, delivery and support, and monitoring. Seven factors are extracted using an exploratory factor analysis as follows : Overall IT planning process, technological assessment process in IT planning of IT, cost-benefit assessment process in IT planning, implementation process, support process, monitoring process, post-implementation evaluation process. The results of confirmatory analysis of three alternative measurement models indicated that the measurement model with one inherent or conceptual variable has greater model fitness than the other models. This study suggests the logical and general way to test and apply COBIT in evaluating IS services.

Evaluation of the Model Accuracy according to Three Types of Dental Scanner (세 가지 방식의 스캐너 종류에 따른 모형 정확도 평가)

  • Lee, Jae-Jun;Park, Jin-Young;Bae, So-Yeon;Jeon, Jin-Hun;Kim, Ji-Hwan;Kim, Woong-Chul
    • Journal of dental hygiene science
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    • v.15 no.2
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    • pp.226-231
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    • 2015
  • The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.

Intra- and inter-rater reliability of muscle thickness measurement of the tibialis anterior using different inward pressures

  • Lee, Seong-Joo;Lim, Ji Young;Lee, Chang-Hyung;Park, Dae-Sung
    • Physical Therapy Rehabilitation Science
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    • v.8 no.4
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    • pp.218-224
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    • 2019
  • Objective: This reliability study examined the effects of applying varying induced inward pressures using a transducer placed at 0° neutral ankle position (NEU) and 15° ankle dorsiflexion (DF) on tibialis anterior (TA) muscle thickness using a custom-made device with a force indicator during rehabilitative ultrasound imaging. Design: Cross-sectional study. Methods: Twenty-four healthy subjects were recruited in this study. Two examiners measured the muscle thickness of the TA at 0° NEU and 15° DF in 3 conditions of inward pressures (1.0 N, 2.0 N, and 4.0 N) using a custom-made holder. The muscle thickness was measured three times for each of the conditions arranged in random order. For intra- and inter-rater reliability, the intraclass correlation coefficients (ICCs) with 95% confidence intervals, standard error of measurement, minimal detectable change, and coefficient of variation were analyzed. One-way repeated measures analysis of variance was conducted for investigating changes of TA muscle thickness according to the inward pressures of the transducers. Results: The intra-rater reliability of TA muscle thickness measurement was excellent (ICC3,1: 0.92-0.96) for all conditions (at both ankle joint angles per varying inward pressure). Likewise, the inter-rater reliability of TA muscle thickness measurement was excellent (ICC2,1: 0.89-0.97) under same conditions. The mean of TA thickness showed the trend of decreasing significantly with increased inward pressures at all ankle joint angles (p<0.05). Conclusions: Use of this custom-made device with a force indicator is useful to accomplish the high intra- and inter-rater reliability of TA muscle thickness measurement at both ankle joint angles in reducing the measurement error.

The Effects of Object Size and Reaching Distance on Upper Extremity Movement (물체 크기와 뻗기 거리가 상지 움직임에 미치는 영향)

  • Bae, Su-Young;Kim, Tae-Hoon
    • The Journal of Korean society of community based occupational therapy
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    • v.10 no.1
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    • pp.51-61
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    • 2020
  • Objectives : The purpose of this study is to investigate the effect of object size and reaching distance on kinematic factors of the upper limb while performing arm reaching for normal subjects. Methods : The subjects of this study were 30 university students who were in D university in Busan, and the measuring tool was CMS-70P(Zebris Medizintechnik Gmbh, Germany), a three-dimensional motion analyzer. The task had six conditions. The average velocity of motion, average acceleration, maximum velocity, and the velocity definite number of movements were measured according to changes in object size(2cm, 10cm) and reaching distance(15%, 37.5%, 60%) when they performed arm reaching. The general characteristics of the subject were technical statistics. One-way ANOVA measurement was used to compare variables when the arm reaching task was performed from two object sizes to three reaching distance, and the post-test was conducted with Tukey test. In addition, an independent t-test was used to analyze the kinematic differences according to the two object sizes at three reaching distances. A two-way ANOVA measurement (3×2 Two-way ANOVA measurement) was performed to identify the interaction of the reaching distance(15%, 37.5%, 60%) and the object size(2cm, 10cm). The statistical significance level α was set to .05. Results : When the size of the object increased, the velocity and maximum velocity also increased, but the definite number of velocity decreased. When the reaching distance increased, the velocity and maximum velocity increased, whereas the definite number of velocity decreased. Conclusion : The clinical significance of this study could be utilized as the baseline data for grading object size and reaching distances when the reaching training is implemented for patients whose central nervous system was damaged.

Development of Wireless ECG Clothing for Dogs with Improved Signal Detection (신호 감지성이 향상된 반려견용 무선 심전도 측정 의복 개발)

  • Kim, Soyoung;Lee, Okkyung;Kwon, Eunsun;Lee, Yejin;Min, Seungnam;Lee, Heeran
    • Journal of the Korean Society of Clothing and Textiles
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    • v.46 no.5
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    • pp.760-771
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    • 2022
  • This study sought to develop clothing for a companion animal that can provide stable ECG measurements. A pattern for the smart clothing of a companion dog was manufactured using the replica method to select a location and method that best suited the stable measurement of ECG and improved the clothing's fitness. The smart clothing was developed as the following three types: strap type, top type, and combined top and vest type with a detachable wireless ECG monitor. The detection abilities of these were observed using the PQRST rate taken after ECG measurements while the three companion dogs were tested while resting and moving. The results revealed that apart from using an electrode, applying a gel pad is the most effective way to achieve stable ECG measurements, and the central chest region is more reliable than the left armpit for providing steady readings. The combined top and vest type showed the highest average ECG PQRST detection number, meaning that the ECG signal measurement was steady. These results may contribute to the measurement of ECG in smartwear for U-Healthcare to measure other biometric data of a companion dog.

Reverse engineering technique on the evaluation of impression accuracy in angulated implants (경사진 임플란트에서 임플란트 인상의 정확도 평가를 위한 역공학 기법)

  • Jung, Hong-Taek;Lee, Ki-Sun;Song, So-Yeon;Park, Jin-Hong;Lee, Jeong-Yol
    • The Journal of Korean Academy of Prosthodontics
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    • v.59 no.3
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    • pp.261-270
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    • 2021
  • Purpose. The aim of this study was (1) to compare the reverse engineering technique with other existing measurement methods and (2) to analyze the effect of implant angulations and impression coping types on implant impression accuracy with reverse engineering technique. Materials and methods. Three different master models were fabricated and the distance between the two implant center points in parallel master model was measured with different three methods; digital caliper measurement (Group DC), optical measuring (Group OM), and reverse engineering technique (Group RE). The 90 experimental models were fabricated with three types of impression copings for the three different implant angulation and the angular and distance error rate were calculated. One-way ANOVA was used for comparison among the evaluation methods (P < .05). The error rates of experimental groups were analyzed by two-way ANOVA (P < .05). Results. While there was significant difference between Group DC and RE (P < .05), Group OM had no significant difference compared with other groups (P > .05). The standard deviations in reverse engineering were much lower than those of digital caliper and optical measurement. Hybrid groups had no significant difference from the pick-up groups in distance error rates (P > .05). Conclusion. The reverse engineering technique demonstrated its potential as an evaluation technique of 3D accuracy of impression techniques.

The Effect of Action Observation Training with Acoustic Stimulation on Balance and Gait in Stroke Patients

  • Kim, Young-Mi;Lee, Ho-Jeong;Lee, Jong-Su
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.4
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    • pp.13-21
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    • 2021
  • PURPOSE: This study examined the effects of action observational training with acoustic stimulation (AOTA) on the balance and gait ability in stroke patients. METHODS: Forty-five chronic stroke patients were divided into three groups. The AOTA group (n = 15) received training via a video that showed a normal gait with the sound of footsteps. The action observation training (AOT) group (n = 15) received AOT without acoustic stimulation. The control group (n = 15) received physical training. Each intervention was applied once per day, three times per week for six weeks. The participants in the AOTA and AOT groups had five minutes of AOT. The participants in the all group had 20 minutes of physical training. All participants were measured using the Berg Balance Scale, the Timed Up and Go Test, the Functional Reaching Test, 10 Meter Walk Test, six Minute Walk Test, and Dynamic Gait Index. The collected data were analyzed using SPSS version 20.0 for Windows. The between- and within-group comparisons were analyzed using the one-way analysis of variance (ANOVA) test and a paired t-test, respectively. For all statistical analyses, the significance level was set to .05. RESULTS: The one-way ANOVA test identified significant differences among the measurement results of the three groups (p < .05). Post hoc analyses indicated the AOTA group to undergo more significant balance and gait changes than the control group (p < .05). CONCLUSION: The gait and balance abilities could be improved effectively for patients with stroke when action observation training and acoustic stimulation were applied simultaneously.