• Journal of Acupuncture Research
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• v.31 no.2
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• pp.99-109
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• 2014

Objectives : The purpose of this study was to analysis the relationship between hours of smartphone use and neck pain in university students. Methods : A survey of 2,353 university students was conducted in Gyeonggi province and Incheon city using a self report questionnaire from April 1 to 11 2013. The questionnaire of questions regarding the hours of using smartphone, mainly used function in participant's smartphone and neck discomfort degree. Neck disability index(NDI) was used to evaluate degree of pain. The collected data were analyzed with the t-test and Kendall's tau test using the SPSS 21.0 program and R 3.1.0, respectively. Results : 1. Almost all of the survey participants(99.07 %) were smartphone users. 66.97 % of them answered that they use their smartphone daily more than 2 hours and 48.18 % of them answered that they use their smartphone 10 to 30 minutes everytime they use it. 2. The overall distribution of NDI scores was 'no disability(0~4 score, 62.92 %)', 'mild disability(5~14 score, 32.85 %)', 'moderate disability(15~24 score, 1.19 %)'. As a result of t-test, we found that the average NDI score for female students was significantly higher than the average NDI score for male students(p<0.05). 3. The Kendall's tau test revealed that total time spent daily using smartphones has a strong positive correlation with 'pain intensity', 'lifting', 'reading' 'headache', 'concentration', and 'driving'(p<0.05) in NDI. Also, time duration of one time smartphone usage has a strong positive correlation with 'pain intensity', 'lifting', 'reading', 'headache', 'concentration', 'work', and 'recreation'(p<0.05). 4. The Kendall's tau test revealed that total NDI scores have a significantly strong positive correlation with both of total time spent daily using smartphones(p<0.05) and time duration for one time smartphone usage(p<0.05). This results imply that long-time use of smartphone has a strong relationship with neck pain. Conclusions : The results of the study would be a good starting point for future studies to reduce the risks of chronic neck pain caused by smartphone usage.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.77-84
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• 2004

A robust optimal control design is proposed in this study for rigid robotic systems under the unknown loads and the other uncertainties. The uncertainties are reflected in the performance index, where the uncertainties are bounded for the quadratic square of the states with a positive definite weighting matrix. An iterative algorithm is presented for the determination of the weighting matrix required for necessary robustness. Computer simulations have been done for a weight-lifting operation of a two-link manipulator and the simulation results shows that the proposed algorithm is very effective for a robust control of robotic systems.

• Journal of the Korean Mathematical Society
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• v.49 no.2
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• pp.293-314
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• 2012

We prove that the Siegel modular form of D'Hoker and Phong that gives the chiral superstring measure in degree two is a lift. This gives a fast algorithm for computing its Fourier coefficients. We prove a general lifting from Jacobi cusp forms of half integral index t/2 over the theta group ${\Gamma}_1$(1, 2) to Siegel modular cusp forms over certain subgroups ${\Gamma}^{para}$(t; 1, 2) of paramodular groups. The theta group lift given here is a modification of the Gritsenko lift.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1995.11a
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• pp.126-138
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• 1995

In order to study the gas interchangeability, a series of tests and analysis were conducted regarding to natural gas and gas mixture. Natural gas was selected as a reference and NG-LPG/Air mixture as a substitute gas. The major interest was placed on the determination of interchangeability limits for different mixing conditions. The parameters of Wobbe Index and Combustion Potential were employed in estimating the gas interchangeability, The limits obtained by analysis(AGA, WEAVER, KNOY, GILB) were compared with experimental results. The results estimated showed that the mixing limits of LPG/Air in proper conditions were found to vary with analysis and AGA is considered to be the most appropriate one.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.876-881
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• 2003

This study focused on to design and toanalysis of a myoelectronic hand. We considered a low frequency factor in human life and to quantify low frequency which a human body responded to using a 1-axis ant a 3-axis accelerometer. The dynamic myoelectronic hand are important for tasks such a continuous prosthetic control and a EMG signal recognition, which have not been successfully mastered by the most neural approached To control myoelectronic hand, classifying myoelectronic patterns are also important. Experimental results of FEM are 110㎫ on Thumb, 200㎫ on Index finger, 220㎫ on Middle finger 260㎫ on Ring finger and 270㎫ on Little finger. Experimental results of accelerometer are 1.4-0.4(m/s2) ,(5-20(〔Hz〕) in Feeding activity and 0.4-0(m/s2) (0-10〔Hz〕) in Lifting activity. Considering these facts, we suggest a new type myoelectronic hand.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.679-690
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• 2017

The purpose of this study was to investigate the relationship between neck posture and range of motion and neck disability index(NDI) in young adults with reduced cervical lordosis. This study selected 34 young adults with cervical lordosis reduced (Cobb's angle less than 35 degrees). The assessor measured neck flexion, extension, left lateral flexion, right lateral flexion, left rotation, right rotation and forward displacements of all subjects using cervical of range motion instrument, Then, the NDI was evaluated. After all assessments, degree for cervical lordosis was divided into two groups: bottom group(severe cervical lordosis) and top group(mild cervical lordosis). The bottom group was significantly higher in Cobb's angle, extension, left lateral flexion, right lateral flexion, left rotation, right rotation and forward displacement compared to the top group (p<.05). There was no significant difference between the two groups in flexion, NDI(p >.05). In comparison of subscale of NDI, top group was significantly higher in pain, lifting, and headache than bottom group (p <.05). In correlation analysis, Cobb's angle showed significant positive correlation with flexion, extension, left lateral flexion, right lateral flexion, left rotation and right rotation(p<.05), and showed significant negative correlation with forward displacement, NDI(p<.05). Cobb's angle showed a significant negative correlation with pain, lifting, and headache of subscale of NDI(p<.05). The findings of this study potentially suggest that neck posture may affect the cervical range of motion and pain.

• Asian Spine Journal
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• v.12 no.6
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• pp.1106-1116
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• 2018

Study Design: Prospective observational study. Purpose: To evaluate the disability domains relevant to Indian patients with low backache and propose a modified disability questionnaire for such patients. Overview of Literature: The Oswestry Disability Index (ODI) is a self-reported measurement tool that measures both pain and functional status and is used for evaluating disability caused by lower backache. Although ODI remains a good tool for disability assessment, from the Indian perspective questions related to weight lifting and sexual activity of ODI are questioned in some of the earlier studies. Activities of daily living in Indian patients vary substantially from those in other populations and include activities like bending forwards, sitting in floor and squatting which are not represented in the ODI. Methods: In this prospective observational study, a seven-step approach was used for the development of a questionnaire. Thirty patients were interviewed to identify the most challenging issue they faced while performing their daily activities (by free listing) and understand how important the questionnaire items were in terms of the standard ODI. Thus, a comprehensive disability questionnaire comprising 14 questions was developed and administered to 88 patients. Both qualitative (interviews) and quantitative methods (to establish the validity, reliability, and correlation with the Visual Analog Scale [VAS] and Rolland Morris disability questionnaire) were used to identify the 10 questions that best addressed the disability domains relevant to Indian patients. Results: According to free listing, four new questions pertaining to bending forward, sitting on the floor, walking on uneven surfaces, and work-related disabilities were included. In the second phase, wherein the questionnaire with 14 items was used, 56.8% patients did not answer the questions related to sexual activity, whereas 23.8% did not answer those related to walking on uneven surfaces. The modified questionnaire demonstrated good internal consistency (Cronbach's alpha=0.892) and correlation with the Rolland Morris questionnaire (Cronbach's alpha=0.850, p>0.05), as well as with the VAS score for disability (Cronbach's alpha=0.712, p>0.05) and pain (Cronbach's alpha=0.625, p>0.05). Conclusions: A modified disability questionnaire that was designed by adding two questions related to bending forward and work status and removing questions related to sexual activity and weight lifting or traveling (depending on the occupation) can help evaluate disability caused by back pain in Indian population.

• The Korea Journal of Herbology
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• v.28 no.2
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• pp.75-82
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• 2013

Objective : This study was to evaluate the effectiveness of the prescription Dokhwalkigisaengtangagambang(DGG) and Gamisayuktanggagambang(GSG), which has been utilized in the treatment of joint disease, for improving low back and knee joint pain. Methods : In the patients for the clinical studies, control group was 28 cases, experimental group was 41 cases. All subjects had low back pain and knee pain. The experimental group was treated with DGG or GSG, the control group was treated with 17 prescriptions. VAS (Visual Analag Scale), WOMAC (Western Ontario and McMasters Universties Osteoarthritis Index) and ODI (Oswestry Low back pain Disability index) measured before and after the prescription administration. Results : In the difference of VAS score, the experimental group (p <0.001) and the control group (p <0.001) were decreased significantly before and after the administration of prescription, and in the comparisons between the experimental group and the control group, experimental group was decreased significantly compared to the control group(p = 0.008). In the WOMAC score, there was no significant difference between the experimental group and the control group. In the difference of ODI items score, lifting (p = 0.020) and sleeping (p = 0.028) index were decreased significantly before and after the administration of prescription. Conclusion : The results indicated that the prescription DGG and GSG can reduce knee pain and low back pain. This study will be helpful for improving joint disease.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.35-43
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• 2006

Reproduction and organ structure of the pale chub, Zacco platypus in Isa stream were investigated by means of histological methods. The results of the study confirmed reproductive abnormality and histopathological features in the pale chub. The gonadosomatic index (GSI) of the fish showed two peak in April and August. In summer season, GSI of the male was about two times of the female's GSI. Monthly variation of the gonadal development was very irregular. From the histological analysis of the organ structure, epidermal atrophy, necrosis and hyperplasia of pigment cell were observed in the skin. Epithelial layer lifting and clubbing of the lamella and bifurcation of the filament were observed in the gill. Also histological changes as congestion, cytoplasmic degeneration of hepatic cell, degeneration of bile duct, glomerular dilatation, degeneration of renal tubule and pycnosis of interstitial cell were identified in the liver and kidney, respectively.

• Safety and Health at Work
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• v.8 no.4
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• pp.356-363
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• 2017

Background: The aim of this study was to investigate which physical and psychosocial work demands were associated with excellent work ability in individuals with neck pain, and to investigate age and sex differences in these associations. Methods: The study sample was obtained from the Statistics Sweden cross-sectional Work Environment survey and consisted of workers who reported neck pain after work (N = 3,212). Results: The findings showed an association between excellent work ability and self-reported low exposure to lifting, twisted work posture, working with hands in shoulder level or higher, and leaning forward without support and combination of exposures containing these work demands. Low exposure to seated work and high demands showed a reversed association. The associations were present mainly among older workers and were generally stronger for men than for women. Conclusion: This study indicates that a lower level of physically demanding work is an important element to maintain excellent work ability, especially for the older worker with neck pain.