• Title/Summary/Keyword: Position measurement

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Development and Evaluation of Wearable Smart Clothing for Combined EMG Devices (웨어러블 근전도 디바이스 결합형 스마트의류 개발 및 성능평가)

  • Sojung Lee;Hyelim Kim;Wonyoung Jeong
    • Fashion & Textile Research Journal
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    • v.25 no.2
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    • pp.210-220
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    • 2023
  • Recently, smart wearable products, including electromyography (EMG) measurement devices and clothing, have been developed to monitor users' exercise levels, muscle activation, and muscle balance more effectively during fitness activities. However, technical and socioeconomic barriers, such as flexibility and durability, still pose challenges in terms of comfort, ease of wear, and wearability of smart clothing, which includes devices and circuits. To address these issues, this study developed a wearable EMG device integrated with clothing to collect valid EMG signals from desired muscles while maintaining comfort, functionality, and ease of wear. After deriving a combined structure that could stably position the wearable device within the clothing, a prototype was manufactured and evaluated for fit, compression, comfort, and exercise comfort test by ten participants (height = 176.2 cm, weight = 76.4 kg, chest circumference = 101.2 cm). The study found that the prototype had smaller circumferences around the chest, waist, and abdomen compared to commercial products, resulting in lower ratings for wearing comfort and ease of wear. However, the prototype received high ratings for fitting, pressure, and the exercise comfort test. Valid signals were obtained when the EMG device was combined to the prototype for the rectus femoris muscle, indicating stable positioning of the device during exercise.

STUDY ON THE RESTORATION MODEL OF JEONGNAM-ILGU, CREATED DURING THE REIGN OF KING SEJONG OF THE JOSEON DYNASTY (조선 세종대에 창제된 정남일구 복원모델 연구)

  • JIWON PARK;BYEONG-HEE MIHN;SANG HYUK KIM;YONG-GI KIM
    • Publications of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.1-12
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    • 2023
  • Numerous Sundials were fabricated during the reign of King Sejong of the Joseon Dynasty. One among them is Jeongnam-Ilgu (the Fixing-South Sundial), where the time can be measured after setting up the suitable meridian line without a compass. We reconstructed the new Jeongnam-Ilgu model based on the records of 'Description of Making the Royal Observatory Ganui (簡儀臺記)' in the Veritable Record of King Sejong. Jeongnam-Ilgu has a summer solstice half-ring under a horizontal ring which is fixed to two pillars in the north and south, and in which a declination ring rotates around the polar axis. In our model, the polar axis matches the altitude of Hanyang (that is Seoul). There are two merits if the model is designed to install the polar axis in the way that enters both the north and south poles and rotates in them: One is that it is possible to fix the polar axis to the declination ring together with the cross-strut. The other is that a twig for hanging weights can be protruded on the North Pole. The declination ring is supposed to be 178 mm in diameter and is carved on the scale of the celestial-circumference degrees on the ring's surface, where a degree scale can be divided into four equal parts through the diagonal lines. In addition, the time's graduation that is drawn on the summer solstice half-ring makes it possible to measure the daytime throughout the year. An observational property of Jeongnam-Ilgu is that a solar image can be obtained using a pin-hole. The position cast by the solar image between hour circles makes a time measurement. We hope our study will contribute to the restoration of Jeongnam-Ilgu.

A Study on Comparison of Response Time using Open API of Daishin Securities Co. and eBestInvestment and Securities Co.

  • Ryu, Gui Yeol
    • International journal of advanced smart convergence
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    • v.11 no.1
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    • pp.11-18
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    • 2022
  • Securities and investment services have and use large data. Investors started to invest through their own analysis methods. There are 22 major securities and investment companies in Korea and only 6 companies support open API. Python is effective for requesting and receiving, analyzing text data from open API. Daishin Securities Co. is the only open API that officially supports Python, and eBest Investment & Securities Co. unofficially supports Python. There are two important differences between CYBOS plus of Daishin Securities Co. and xingAPI of eBest Investment & Securities Co. First, we must log in to CYBOS plus to access the server of Daishin Securities Co. And the python program does not require a logon. However, to receive data using xingAPI, users log on in an individual Python program. Second, CYBOS plus receives data in a Request/Reply method, and zingAPI receives data through events. It can be thought that these points will show a difference in response time. Response time is important to users who use open APIs. Data were measured from August 5, 2021, to February 3, 2022. For each measurement, 15 repeated measurements were taken to obtain 420 measurements. To increase the accuracy of the study, both APIs were measured alternately under same conditions. A paired t-test was performed to test the hypothesis that the null hypothesis is there was no difference in means. The p-value is 0.2961, we do not reject null hypothesis. Therefore, we can see that there is no significant difference between means. From the boxplot, we can see that the distribution of the response time of eBest is more spread out than that of Cybos, and the position of the center is slightly lower. CYBOS plus has no restrictions on Python programming, but xingAPI has some limits because it indirectly supports Python programming. For example, there is a limit to receiving more than one current price.

Measurement of Residual Stress Distribution in the Depth Direction of Annealed Materials of Lapped Bearing Steel Using Weighted Averaging Analysis Method (가중평균 해석법을 이용한 래핑된 베어링강 어닐링재료의 깊이방향에 대한 잔류응력분포 측정)

  • Chang-Suk Han;Chan-Woo Lee
    • Korean Journal of Materials Research
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    • v.33 no.5
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    • pp.205-213
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    • 2023
  • This paper reports the results of an experimental examination using X-rays to test annealing materials for lapped bearing steel (STB2), to confirm the validity of the weighted averaging analysis method. The distribution behavior for the α𝜓-sin2𝜓 diagram and the presence or absence of differences in the peak method, half-value breadth method, and centroid method were investigated. When lapping the annealed bearing steel (STB2) material, a residual stress state with a non-directional steep gradient appeared in the surface layer, and it was found that the weighted averaging analysis method was effective. If there is a steep stress gradient, the sin2𝜓 diagram is curved and the diffraction intensity distribution curve becomes asymmetric, resulting in a difference between the peak method, half-value breadth method, and centroid method. This phenomenon was evident when the stress gradient was more than 2~3 kg/mm2/㎛. In this case, if the position of the diffraction line is determined using the centroid method and the weighted averaging analysis method is applied, the stress value on the surface and the stress gradient under the surface can be obtained more accurately. When the stress gradient becomes a problem, since the curvature of the sin2𝜓 diagram appears clearly in the region of sin2𝜓 > 0.5, it is necessary to increase the inclination angle 𝜓 as much as possible. In the case of a lapping layer, a more accurate value can be obtained by considering 𝜎3 in the weighted averaging analysis method. In an isotropic biaxial residual stress state, the presence or absence of 𝜎3 can be determined as the presence or absence of strain for sin2𝜓≈0.4.

A Study on the Visibility Measurement of CCTV Video for Fire Evacuation Guidance (화재피난유도를 위한 CCTV 영상 가시도 측정에 관한 연구)

  • Yu, Young-Jung;Moon, Sang-Ho;Park, Seong-Ho;Lee, Chul-Gyoo
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.12
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    • pp.947-954
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    • 2017
  • In case of a fire in urban large structures such as super high-rise buildings, evacuation guidance must be provided to the occupants in order to minimize human deaths and injuries. Therefore, it is essential to provide emergency evacuation guidance when a major fire occurs. In order to effectively support evacuation guidance, it is important to identify major items such as fire location, occupant position, escape route, etc. Also, it is important to quickly identify evacuation areas where residents can safely evacuate from a fire. In this paper, we analyze the CCTV video and propose a method of measuring visibility of the evacuation zone from the smoke caused by the fire in order to determine the safety of evacuation area. To do this, we first extract the background video from the smoke video to measure the visibility of the specific area due to smoke. After generating an edge-extracted image for the extracted background video, the degree of visibility is measured by calculating the change in the edge strength due to smoke.

Effect of Cable Tension Changes on Track Irregularity of Railway Ballasted Track on Railway Steel Composite Bridge (케이블 장력변화가 강철도 복합교량 상 자갈궤도의 궤도틀림에 미치는 영향)

  • Jung-Youl Choi;Soo-Jae Lee
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.4
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    • pp.633-638
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    • 2023
  • In this study, the effect of the change in cable tension on the track irregularity of railway ballasted track on a railway steel composite bridge was analyzed. As a result of comparing design and analysis results for cable tension, a difference of less than 3% was found, and analysis modeling was analyzed to reflect the design conditions well. In addition, the adequacy of the analysis modeling was demonstrated by comparing the field measurement results with the analysed cable tension. By considering the change in cable tension as a variable, the track irregularity of the railway steel composite bridge was analyzed. As a result of the analysis, it was analyzed that the total and one-sided cable tension change had a direct effect on the vertical irregularity among the track irregularity items. In addition, it was found that the change in track irregularity occurred in the section close to the cable position. It was analyzed that the change in cable tension had a more direct effect on track irregularity that had a direct correlation with the vertical direction rather than the lateral direction.

Tension Measurement of Stay Cables in Consideration with Image Including Vehicle (차량이 포함된 이미지를 고려한 사장재 케이블의 장력 측정 )

  • Sung-Wan Kim;Dong-Uk Park;Jin-Soo Kim;Seung-Su Park;Jae-Bong Park
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.58-66
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    • 2023
  • In this study, cable tension was measured using the vibration method, and a vision-based system was applied as a sensor to measure the displacement response of a cable in a non-contact method. In the vision-based system, the camera is installed in a location that considers the target structure and the field of view of the camera. However, it can be difficult to recognize the control points required to measure the displacement response of a structure as the target structure and other structures such as vehicles may be included in the image at the intended installation location. In this study, a distorted image including a vehicle shows inaccurate results in image analysis due to the installation position of the vision-based system. Accordingly, the image including the vehicle was eliminated by calculating the similarity between the two images. To verify the validity of the method of estimating the cable tension of cable-stayed bridges using the proposed method, the vibration method was applied to cable-stayed bridges in service to measure the tension.

Effects of Death Anxiety and Perceived End-of-Life Care Competencies on Fear of Terminal Care among Clinical Nurses

  • Heewon Kim;So-Hi Kwon
    • Journal of Hospice and Palliative Care
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    • v.26 no.4
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    • pp.160-170
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    • 2023
  • Purpose: The aim of this study was to examine the effects of death anxiety and perceived end-of-life care competencies on the fear of terminal care among clinical nurses. Methods: This correlational study was conducted from June to July 2021. The study included 149 clinical nurses employed at a tertiary hospital and seven other hospitals. The measurement tools used in this study were the Thanatophobia Scale (Cronbach's α=0.87), the Death Anxiety Scale (Cronbach's α=0.80), and the Scale of End-of-life Care Competencies (Cronbach's α=0.94). These instruments were chosen to assess the levels of fear of terminal care, death-related anxiety, and competencies in end-of-life care. Results: The mean score for fear of terminal care was 3.32±1.32. Differences in fear of terminal care were observed based on the working unit, position, number of patients requiring terminal care, and experience with end-of-life care education. Fear of terminal care was significantly positively correlated with death anxiety and significantly negatively correlated with end-of-life care competencies. In multiple regression analysis, the factors influencing fear of terminal care were attitudes toward end-of-life care competencies (𝛽=-0.39, P<0.001), death anxiety (𝛽=0.24, P<0.001), knowledge of end-of-life care competencies (𝛽=-0.22, P=0.005), and behaviors related to end-of-life care competencies (𝛽=-0.16, P=0.021). These factors explained 64.6% of the total variance (F=25.54, P<0.001). Conclusion: This study suggests that developing nurses' end-of-life care competencies and reducing death anxiety are crucial for managing the fear of terminal care. Therefore, providing end-of-life care education and psychological support programs is important.

Classification of Torso Shapes of Women Aged 35-54 - Based on Measurements Extracted from the 8th Size Korea Scans - (35-54세 여성의 토르소 형태 분류에 관한 연구 - 제8차 Size Korea 인체형상으로부터 추출한 측정값을 이용하여 -)

  • Yu Rui;Eun Joo Ryu;Hwa Kyung Song
    • Fashion & Textile Research Journal
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    • v.25 no.5
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    • pp.603-614
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    • 2023
  • Body shape is the most influential factor in determining the quality of clothing fit. Women's body shape begins to change significantly in their mid-30s; therefore, this study aimed to classify and analyze the torso shapes of women aged 35-54 years. This study selected 200 3D body scans of women from the 8th Size Korea Survey database (2021). Using the Grasshopper algorithm developed in a previous study, 17 landmarks were automatically detected and 57 measurement values were generated. Using principal component analysis, 11 components (overall body size, upper body length, back protrusion, upper body slope, neck position, neck inclination, hip length, bust prominence, abdominal prominence, shoulder slope, and buttock prominence) were extracted. Three torso types were identified using K-means cluster analysis. The three body types were significantly different on nine component scores. Among the three torso types, Type 1 (37.5%) has the longest upper body and the flattest back and hips. Type 2 (31.0%) has the most curved back and forward upper body. Its abdomen is the flattest, and its shoulders are the most sloped. Type 3 (31.5%) has the shortest upper body, the most protruding hips, and the largest overall body size. This paper proposes two discriminant functions for identifying a new person's torso type.

A Study on Adaptive Front-Lighting System based on Diffractive Optical Element (회절 광학 소자 기반 적응형 전조등 시스템 연구)

  • Seong-Uk Shin;Seung-Ho Park;Kyoung-Sun Yoo;Myeong-Jae Noh
    • Advanced Industrial SCIence
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    • v.2 no.4
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    • pp.28-35
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    • 2023
  • In this paper, a diffractive optical element was designed to create lighting patterns that satisfy the requirements of adaptive headlight systems for normal road mode, highway mode, and wet road mode, and this was rendered into a GDSII stream format file.To verify the effectiveness of the light distribution formed by the diffractive optical elements and the realization of white light, simulations based on Field Tracing and Ray Tracing were conducted, confirming the satisfaction of position and luminance requirements at the transformation beam measurement points. Based on this research, it is anticipated that the implementation of adaptive headlights would be possible, enabling the reproduction of luminance contrast and the creation of a simple-structured adaptive headlight system.