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The Effects of Trunk Movement and Ground Reaction Force during Sit to Stand Using Visual Feedback (시각 되먹임을 이용한 앉은 자세에서 일어서기 시 몸통의 동작과 지면 반발력에 미치는 영향)

  • Yeong-Geon Koh;Tae-Young Oh;Jae-Ho Lee
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.2
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    • pp.207-219
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    • 2023
  • Purpose : This study was conducted to investigate the changes in trunk movement and ground reaction during sit to stand motion using visual feedback. Methods : Fifteen adults (average age: 23.53±1.77 years) participated in this study. An infrared reflective marker was attached to the body each participant for motion analysis, and the participants performed sit to stand motion while wearing a hat attached with a laser pointer, which provided visual feedback. First, the sit to stand action was repeated thrice without obtaining any visual feedback, followed by a three minute break. Next, the laser pointers attached to hats were irradiated on a whiteboard, located at a distance of 5 m in front of the chairs, on which the participants sat; a baseline was set, and the participants performed stand up movements three times under this condition. A visual feedback was provided to the participants to prevent the laser pointers from crossing the set baseline. During each stand-up movement, the position of the reflective marker attached to the subject's body was recorded in real time using an infrared camera for motion analysis. The trunk movement and ground reaction force were extracted through recorded data and analyzed according to the presence or absence of visual feedback. Results : The results indicated that in the presence of a visual feedback during the sit-to-stand movements, the range of motion of the trunk and hip joints decreased, whereas that of the knee and ankle joints increased in the sagittal plane. The rotation angle of the trunk in the horizontal plane decreased. The left and right movement speed of the center of pressure increased, the pressing force decreased, and the forward and backward movement speed of the trunk decreased. Conclusion : The results suggest that the efficiency and stability of the stand up movement of a body increase when a visual feedback is provided.

A Study on the Decomposition of Litter and the Leaching of Mineral Nutrients in the Stands of Pinus rigida on Mt. Gwan-ak and Pseudosasa japonica on Odong-do (관악산의 리기다소나무림과 오동도의 이대림에서 낙엽의 분해와 무기양분의 세탈에 관한 연구)

  • Chang, Nam-Kee;Heui-Baik Kim;Jun-hi Yoo
    • The Korean Journal of Ecology
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    • v.9 no.1
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    • pp.51-58
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    • 1986
  • The decay rates of organic matter were investigated and the leaching rates were determined from the concentration distribution of N,P,K, Ca and Na in the soil profile at Pinus rigida stand on Mt. Gwan-ak and at Pseudosasa japonica stand on Odong-do. In order to determine the leaching rates θo/W wazs substituted with KL in Towner's equation. Decay rates were 0.191 at Pinus stand on Mt. Gwan-ak and 0.234 at Pseudosasa stan don Odong-do. Concentration distributions of N,P, K and Na in soil profiles were corresponed with Towner's model curve. Leaching rates determined from concentration distributions were 0.086, 0.079, 0.041, 0.029, 0.096 on Mt. Gwan-ak and 0.080, 0.056, 0.051, 0.008, 0.028 on Odong-do. The soil of Pseudosasa stand showed on the whole lower leaching rates than that of Pinus stand. The soil of Pseudosasa stand showing higher decay rate and lower leaching rates contained more concentration of each nutrient than that of Pinus stand.

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Rate of Soil Respiration at Black Locust(Robinia pseudo-acacia) Stands in Jinju Area

  • Moon, Hyun-Shik;Jung, Su-Young;Hong, Sung-Cheon
    • The Korean Journal of Ecology
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    • v.24 no.6
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    • pp.371-376
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    • 2001
  • The rate of soil respiration to varying stand ages was studied in four Robinia pseudoacacia stands(18-, 23-, 28- and 35-year old) throughout one year from September 1998 to August 1999. Soil temperatures showed a pronounced seasonal pattern, in contrast to soil moisture. The highest rate of soil respiration was generally found in August when soil temperatures were the highest, and the lowest in January. The daily rate of soil respiration amounted to 5.51($g\;CO_2{\cdot}m^{-2}{\cdot}day^{-1}$) for 18-year old stand, 5.28 for 23-year old stand, 8.29 for 28-year stand, and 2.67 for 35-year old black locust stand, respectively. The $Q_{10}$ values were ranged between 1.63 and 1.66, averaging 1.65 for the R. pseudoaca'cia stands. The results indicate significant correlation between soil temperature and soil respiration for all four stands(r=0.96 to 0.97). Among the study stands, the annual rate of soil respiration was the highest ($3.03kg\;CO_2{\cdot}m^{-2}{\cdot}yr^{-1}$) for 28-year old stand.

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Effect of Task-Oriented Approach on Weight-Bearing Distribution and Muscular Activities of the Paretic Leg During Sit-to-Stand Movement in Chronic Stroke Patients (과제지향적 접근법이 만성 뇌졸중 환자의 일어서기 동작 시 환측다리의 체중지지비율과 근활성도에 미치는 영향)

  • Kim, Won-Ho
    • Physical Therapy Korea
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    • v.18 no.2
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    • pp.18-26
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    • 2011
  • The purpose of this study was to investigate the effects of a task-oriented approach on weight-bearing distribution and muscular activities of the paretic leg during sit-to-stand movement in 18 chronic stroke patients. Both groups were received neurodevelopmental treatment for 30 min/day and then the experimental group ($n_1$=9) followed additional a task-oriented approach (sit-to stand training with controlled environment) and the control group ($n_2$=9) followed a passive range of motion exercise for 15 min/day, five days/week, for four weeks. Weight-bearing distribution and muscular activities of the paretic leg during sit-to-stand movement were measured before and after four weeks of training. There was significantly improved weight-bearing distribution of the paretic leg during sit-to-stand movement in the experimental group compared with that of the control group after four weeks of training (p<.05). But electromyographic activities of the quadriceps and the tibialis anterior of the paretic leg were not significantly different (p>.05). Thus, it is necessary to apply a task-oriented approach to improve the weight-bearing distribution of the paretic leg during sit-to-stand movement in chronic stroke patients.

Aerodynamic Resistance and Eddy Diffusivity above the Plug Stand under Artificial Light (인공광하에서 공정묘 개체군상의 공기역학적 저항 및 확산계수)

  • 김용현;고재풍수
    • Journal of Bio-Environment Control
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    • v.5 no.2
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    • pp.152-159
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    • 1996
  • Experiment was performed in a newly developed wind tunnel with light system to determine the aerodynamic resistance and eddy diffusivity above the plug stand under artificial light. Maximum air temperature appeared near the top of the plug stand under artificial light. Since Richardson number was ranged from -0.07 to +0.01, the atmosphere above the plug stand in wind tunnel was in an unstable or near- neutral stability state. The average aerodynamic resistance at rear region of plug stand was 25 % higher than that at middle region. Eddy diffusivity($K_{M}$) linearly increased with the increasing air current speed. $K_{M}$ at air current speed of 0.9 m.$s^{-1}$ was about two times as many as that at air current speed of 0.3 m.$s^{-1}$. And average $K_{M}$ at the rear region was 15% lower than that at the middle region. These results indicated that the diffusion of heat and mass along the direction of air current inside the plug stand was different. It might cause the lack of uniformity in the growth and quality of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on microclimates and the growth of plug seedlings under artificial light in a semi- closed ecosystem.

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The Effect of the Laptop Computer Stand to Maintain the Good Posture of Neck (랩톱 컴퓨터 스탠드의 목 자세 개선효과 분석)

  • Oh, Imsuk;Lee, Jaehyun;Chee, Youngjoon
    • Journal of Biomedical Engineering Research
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    • v.38 no.6
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    • pp.291-294
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    • 2017
  • It is known that laptop computer stand is helpful to maintain the good posture while using laptop computer on the desk. But the quantitative validation of its effect has not been reported. Using the wearable neck posture tracker, the forward flexion angle of the neck can be measured in daily life. In this study, the forward flexion angles of the neck while using the laptop computer with and without laptop computer stand were compared. From the posture data of 10 subjects for 6 hours, the average of the forward flexion angle was 0.9 degree with laptop computer stand and 16.3 degree without laptop computer stand. As the conclusion, laptop computer stand can decrease the forward flexion angle which is known as forward head posture while using the laptop computer on the desk.

A Development of a LED Stand Using Illuminance Sensor for Efficient Energy Saving (효율적인 에너지 절감을 위한 센서 LED 스탠드 개발)

  • Chun, Sung-Yong;Shin, Ji-Yea;Park, Shin-Won;Yi, Hwa-Cho;Lee, Chan-Su
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.9
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    • pp.1-7
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    • 2012
  • In this paper, we present a new lighting control method considering ambient light in addition to the required lighting illumination for efficient energy saving of a LED stand. We estimate accurate environmental illuminance using a cheap illuminance sensor by modeling measured- and actual-illuminance using quadratic polynomial approximation. The relation between PWM(Pulse Width Modulation) duty ratio and illuminance intensity is modeled by a linear model. Illumination of the LED stand is controlled by estimating the difference of required illumination and the estimated ambient illumination. The developed LED stand has reduced electric energy consumption compared with a conventional manually controlled LED stand with the same lighting source. In addition, human subject evaluation shows that the LED stand, which is applied the proposed method, is more satisfactory than conventional ones since the proposed automatic controlled illumination produce more accurately required lighting and it is convenient.

Performance Analysis of Neural Network on Determining The Optimal Stand Management Regimes (임분의 적정 시업체계분석을 위한 Neural Network 기법의 적용성 검토)

  • Chung, Joo Sang;Roise, Joseph P.
    • Journal of Korean Society of Forest Science
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    • v.84 no.1
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    • pp.63-70
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    • 1995
  • This paper discusses applications of neural network to stand stocking control problems. The scope of this research was to develop a neural network model for finding optimal stand management regimes and examining the performance of the model for field application. Performance was analyzed in consideration of the number of training examples and structural aspects of neural network. Research on network performance was based on extensive optimization studies for pure longleaf pine(Pinus palustris) stands. For experimental purposes. an existing nonlinear even-aged stand optimization model with a whole-stand growth and yield simulator was used to generate data samples required for the performance analysis.

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Effects of Ditching on Seedling Stand in Wet Direct Seeding Rice Culture

  • Back, Nam-Hyun;Kang, Si-Yong;Kim, Sang-Su;Kwon, Tae-Oh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.1
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    • pp.47-52
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    • 2001
  • In order to develop more stable seedling stand method in wet direct rice seeding culture, the effect of making the drainage ditches was studied in both methods of broadcast seeding on floody paddy surface and puddled-soil drill seeding. In a broadcast seeding on floody paddy surface, the ditching after seeding using a tractor or small ditch maker improved the seedling stand, and reduced the floating seedling and herbicide injury by accelerating the drainage. Suitable ditching time was at 2 days after seeding (DAS) for the tractor and at 3 DAS for the ditch maker. In the puddled-soil drill rice seeding culture, the ditching before seeding with a ditch maker at 3 days after draining effectively improved the seedling stand due to quick draining through well formed the seeding furrows. In the puddled-soil drill seeding, seedling stand number showed higher in both ditching plots synchronized with seeding compared with both only draining treatment at 1 DAS without ditching and the flooding plot condition for 6 DAS. And the suitable ditching depth was 6 cm, as considered the ditching status and drained status. These results suggest that the ditching in wet direct rice seeding is an resonable practice for improving the seedling stand through the accelerating drainage of field.

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Case Studies on Application of Injunction to the stand-by Credit Transactions (보증신용장거래에세 지급금지명령의 적용에 관한 분쟁사례연구)

  • Kang Won-Jin;Lee Sang-Hun
    • Journal of Arbitration Studies
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    • v.14 no.1
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    • pp.29-60
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    • 2004
  • Recently stand-by credits are using as surety devices in various global business transactions including sale of goods. Stand-by credits have lots of merits but simultaneously have high possibility of improper demand by the beneficiary due to the characteristics of the documents required. So so-called fraud rule has developed as a solution to the improper demand in letter of credit transactions. And the actual way of the fraud rule is the injunction by the competent court. The purpose of this article is to examine the applicability of the injunction in stand-by credit transactions by means of case studies. For this purpose, the author examined the concept of the injunction, necessity of the injunction in stand-by credit transactions and the cases of injunction granted and injunction denied. Firstly, the courts have legal standard of the application of injunction due to the legislation of the relative articles in the United Nations Convention on Independent Guarantees and Stand-by Letters of Credit and the Uniform Commercial Code. Secondly, the courts have taken a negative attitude granting injunction in order to observe the independence principle. Thirdly, the courts have a tendency to grant injunction when the demand has no conceivable basis and the applicant will suffer irreparable injury without injunction. Finally, like the saying 'prevention is the best cure', the applicant always pays attention with reasonable care before improper demand by the beneficiary.

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