• 한국전문물리치료학회지
• /
• 제30권3호
• /
• pp.211-220
• /
• 2023

Background: Smartphone addiction has emerged as a significant social problem. Numerous studies have indicated the association between smartphone use and discomfort in the musculoskeletal system of the upper extremities. Objects: This cross-sectional survey aimed to compare the characteristics of musculoskeletal pain in the neck, trunk, and upper limbs between individuals with smartphone addiction and those without addiction. Methods: We collected a total of 326 healthy individuals' data from China and Korea who had owned and used smartphones for more than 5 years between 20-50s through an online questionnaire consisting of 84 questions in four major sections. The first part contained basic information on the participant's personal characteristics and smartphones. The second part contained questions about smartphone use and posture. The third part was the smartphone addiction. The fourth part was to investigate musculoskeletal pain in various upper body parts. Results: Smartphone addiction has a weak negative correlation with age (r = -0.20, p < 0.01) and a weak positive correlation with the hours of smartphone use (r = 0.376, p < 0.01). Frequent musculoskeletal pain symptoms related to smartphone use were observed in the neck, shoulder, lower back, and wrists. The hours of smartphone use was slightly positively associated with the prevalence of musculoskeletal pain in the shoulder (r = 0.162, p < 0.05) and lower back (r = 0.125, p < 0.05). The prevalence of musculoskeletal pain in the neck (χ² = 3.993, p < 0.05), shoulder (χ² = 6.465, p < 0.05), and wrist (χ² = 4.645, p < 0.05) was significantly higher among females than males. Conclusion: The results suggest that smartphone addiction should be recognized as a dual concern encompassing both physical health and psychosocial aspects. Furthermore, healthcare professionals, including physicians and physical therapists, should consider clients' smartphone usage patterns when assessing and treating with musculoskeletal pain.

• 한국운동역학회지
• /
• 제16권4호
• /
• pp.95-103
• /
• 2006

The purpose of this study was to review the relevant literature about coaching and thereupon, survey the coaching methods used for golf lesson to reinterpret them and thereby, describe in view of kinetics the swing errors committed frequently by amateur golfers and suggest more scientific golf coaching methods. For this purpose, kinetic elements were divided into accuracy and power ones and therewith, the variables affecting such elements were identified. For this study, a total of 60 amateur golfer were sampled, and their swing forms were photographed with two high-speed digital cameras, and the resultant images were analyzed to determine the errors of each form kinetically, which would be analyzed again with the program V1-5000. The kinetic elements could be identified as accuracy, power and accuracy & power. Thus, setup and trajectory were classified into accuracy elements, while differences of inter-joint angles, cocking and delayed hitting. Lastly, timing and axial movement were classified into accuracy & power elements. Three errors were identified in association with setup. The errors related with trajectory elements accounted for most (6) of the 20 errors. Three errors were determined for inter-joint angle differences, and one error was associated with cocking and delayed hitting. Lastly, one error was classified into timing error, while five errors were associated with axial movement. Finally, as a result of arranging the errors into a cross table, it was found that the errors were associated with each other between take-back and back-swing, take-back and follow-through, back-swing and back-swing top, and between back-swing and down-swing. Namely, an error would lead to other error repeatedly. So, it is more effective to identify all the errors for every form and correct them comprehensively rather than single out the errors and correct them one by one.

• The Journal of Korean Physical Therapy
• /
• 제20권4호
• /
• pp.21-28
• /
• 2008

Purpose: We measured the Oswestry Low Back Pain Disability Index (OLBPDI) and related factors in patients with low back pain. Methods: The sample consisted of 50 patients who received physical therapy at the physical therapy units of the Andong Seoul Sintong Clinic, St. Luke Clinic, and Yeongju Seoul Sintong Clinic in Andong and Yeongju city from October, 2007, to February, 2008. The OLBPDI questionnaire was administered by 5 physical therapists as a cross-sectional study. Student's t-test and analysis of variance (ANOVA/Tukey and Scheffe) were used to analyze OLBPDI score differences. We also used nonparametric statistic analysis (Wilcoxon rank sum test, Median test). Pearson correlation analysis (Spearman correlation analysis) was used to analyze the relationship between OLBPDI and the visual analogue scale (VAS). Multiple regression analysis was performed to determine the effects of independent variables on pain scores as defined by the OLBPDI. Results: The average patient age was 37.1 years (range: 18$\sim$78 years old), and time from onset was 21.7 months (1$\sim$180). OLBPD and VAS scores were 12.70 (3.0$\sim$28.0) and 5.14 (1$\sim$8), respectively. OLBPDI scores were 14.4 in patients taking medicine and 11.57 in those who did not. There was a statistically significant relationship between OLBPDI and VAS (r=0.54, p=0.0001; r=0.55, p=0.0001 by Spearman coefficient). Gender ($\beta$=6.14, p=0.0124), age ($\beta$=-2.01, p=0.0324), weight ($\beta$=0.31, p=0.0222), time from onset ($\beta$=1.54, p=0.0044), and VAS score ($\beta$=1.59, p=0.0004) were significantly associated with OLBPD by multiple regression analysis. Conclusion: Variables associated with OLBPD were gender, age, weight, time from onset, and VAS score. Collecting information on the pain index using OLBPDI was acceptable to patients with low back pain. Further research should explore the pain index by using larger sample sizes and longer follow-up periods.

• 패션비즈니스
• /
• 제21권5호
• /
• pp.91-108
• /
• 2017

Interests in 3D virtual clothing technology and its application in online shopping malls are increasing with the advent of the Fourth Industrial Revolution. Most studies on 3D virtual clothing, however, are focused on observing drapes or ease of virtual clothing depending on fabric properties of representative clothing items. Therefore, the purpose of this study is: first, to determine if current input of typical material characteristics in 3D CLO are sufficient to formulate virtual skirts with different front and back silhouettes; second, to determine if subjective appearance evaluation matched physical shape characteristics of those skirts. In this study, appearances of typical cotton, wool, silk, rayon, and polyester skirts with different front and back pattern were compared between actual and virtual clothing depending on fabric materials. Subjective appearance evaluation was conducted by 7 experts regarding similarity between actual and virtual clothing with a 5-point scale. For objective evaluation of the both types of skirt shape, degree of roundness at the cross section, displacement of side seam, position of back waistline, and the number of folds at the skirt back were observed. In the case of cotton and wool, not the subjective appearance evaluation as well as shape characteristics of virtual skirts were well matched to the actual shape of skirts with a few material inputs. However, current material inputs for silk, rayon and polyester were insufficient to cover material differences in formation of virtual skirts with different front and back silhouettes.

• 한국수소및신에너지학회논문집
• /
• 제28권4호
• /
• pp.338-344
• /
• 2017

Polyoxometal molybdophosphoric acid (MoPA) bonded polyether ether ketone (PEEK) composite membrane for water electrolysis has been investigated. The composited membrane, covalently cross linked (CL) sulfonated polyether ether ketone (SPEEK) with a bonded MoPA, was prepared in sulfonation of PEEK, cross linkage reaction with 1,4-diiodobutane, and addition with MoPA. PEEK was covalently cross-linked with 1,4-diiodobutane to improve mechanical strength and was added with MoPA to increase proton conductivity. MoPA should be fixed to back bone of SPEEK to prevent bleeding out. Therefore, the carbonyl group of SPEEK was reduced with NaBH4 and 3-isocyanatepropyltriethoxysilane (ICPTES) was added. The MoPA bonded composite was produced in the reaction of MoPA with 3-mercaptopropyltrimethoxvsilane (MPTMS). In conclusion, MoPA bonded CL-SPEEK composite membrane featured 0.129 S/cm of proton conductivity at $80^{\circ}C$, and 2,156 hours of chemical stability in Fenton test. These properties are better than those of membranes of other SPEEK system.

• 한국재료학회지
• /
• 제22권6호
• /
• pp.303-308
• /
• 2012

This study evaluated the enhancement of microstructural and mechanical properties of a cross rolled Ni-10Cr alloy, comparing with conventionally rolled material. Cold rolling was carried out to 90% thickness reduction and the specimens were subsequently annealed at $700^{\circ}C$ for 30 min to obtain a fully recrystallized microstructure. Cross roll rolling was carried out at a tilted roll mill condition of $5^{\circ}$ from the transverse direction in the RD-TD plane. In order to observe the deformed microstructures of the cold rolled materials, transmission electron microscopy was employed. For annealed materials after rolling, in order to investigate the grain boundary characteristic distributions, an electron back-scattering diffraction technique was applied. Application of cold rolling to the Ni-10Cr alloy contributed to notable grain refinement, and consequently the average grain size was refined from 135 ${\mu}m$ in the initial material to 9.4 and 4.2 ${\mu}m$ in conventionally rolled and cross rolled materials, respectively, thus showing more significantly refined grains in the cross rolled material. This refined grain size led to enhanced mechanical properties such as yield and tensile strengths, with slightly higher values in the cross rolled material. Furthermore, the <111>//ND texture in the CRR material was better developed compared to that of the CR material, which contributed to enhanced mechanical properties and formability.

• Journal of Korean Neurosurgical Society
• /
• 제53권3호
• /
• pp.174-179
• /
• 2013

Objective : Many studies have investigated paraspinal muscle changes after posterior lumbar surgery, including lumbar fusion. However, no study has been performed to investigate back muscle changes after pedicle based dynamic stabilization in patients with degenerative lumbar spinal diseases. In this study, the authors compared back muscle cross sectional area (MCSA) changes after non-fusion pedicle based dynamic stabilization. Methods : Thirty-two consecutive patients who underwent non-fusion pedicle based dynamic stabilization (PDS) at the L4-L5 level between February 2005 and January 2008 were included in this retrospective study. In addition, 11 patients who underwent traditional lumbar fusion (LF) during the same period were enrolled for comparative purposes. Preoperative and postoperative MCSAs of the paraspinal (multifidus+longissimus), psoas, and multifidus muscles were measured using computed tomographic axial sections taken at the L4 lower vertebral body level, which best visualize the paraspinal and psoas muscles. Measurements were made preoperatively and at more than 6 months after surgery. Results : Overall, back muscles showed decreases in MCSAs in the PDS and LF groups, and the multifidus was most affected in both groups, but more so in the LF group. The PDS group showed better back muscle preservation than the LF group for all measured muscles. The multifidus MCSA was significantly more preserved when the PDS-paraspinal-Wiltse approach was used. Conclusion : Pedicle based dynamic stabilization shows better preservation of paraspinal muscles than posterior lumbar fusion. Furthermore, the minimally invasive paraspinal Wiltse approach was found to preserve multifidus muscles better than the conventional posterior midline approach in PDS group.

• 한국산학기술학회논문지
• /
• 제17권7호
• /
• pp.256-262
• /
• 2016

본 연구에서는 자동차 자동변속기의 핵심 부품인 아웃풋 허브 및 리액션 허브의 치형 미성형 구간의 최소화를 위한 배압 냉간 단조 성형 공법에 대한 유한요소해석을 수행하였다. 변위제어해석으로 펀치 하중 및 슬리브 배압력을 도출하였고, 도출된 하중 및 배압력을 이용한 하중제어해석을 수행하여 상호 검증을 하였다. 변위제어해석과 하중제어해석이 유사한 경향을 보였으며, 아웃풋 허브와 리액션 허브의 미성형 구간을 기준 이하로 만족시키기 위한 펀치 하중과 슬리브 배압력을 구하였다. 리액션 허브의 펀치 하중이 아웃풋 허브 보다 큰 이유는 상부 치형 가공 시 리액션 허브의 단면감소율이 아웃풋 허브 보다 크기 때문인 것으로 판단되며, 슬리브 배압력이 아웃풋허브와 리액션 허브에서 차이가 나는 것 또한 슬리브 단면적의 차이에 기인한 것으로 판단된다. 본 연구에서 제시한 배압 냉간 단조 성형 해석 과정과 결과를 적용한 실제 치형 가공의 미성형 구간 결과와 비교하여 검증 평가하였으며, 치형 제품의 품질 개선 및 생산성 향상을 위해 요구되는 성형가공 조건을 도출하는데 유용하게 활용될 수 있을 것이다.

• Journal of Plant Biotechnology
• /
• 제31권4호
• /
• pp.261-266
• /
• 2004

Agrobacterium을 이용하여 도입된 유전자의 세대진전, 교잡 등에 따른 유전적 안정성을 확인코자, 형질 전환으로부터 얻어진 bar 유전자가 도입된 형질전환 식물체들을 상호 교배, 여교배, T$_4$ 세대까지의 자식의 반복 등에 의해 유전적 안정성을 검토하였다. 조합이나 계통에 따라서는 일부 멘델식 분리를 따르지 않고 제초제 Basta에 대한 저항성이 사라지거나 저항성개체보다 감수성개체가 기대치보다 많은 등의 경우가 있었으나, 대부분 멘델식 분리를 따르고 있어 세대진전, 교배 등에 의해서도 유전적 안정성이 높게 유지됨을 확인할 수 있었다.

• 한국임상보건과학회지
• /
• 제1권2호
• /
• pp.21-29
• /
• 2013

Purpose. This study was to investigate that the adjustment of Chiropractic pelvis method have effect on body balance and improvement people who has some problem in their daily life. Methods. With 20 students of experiment group and 20 students of compare group who has cervical syndrome, experiment group has adjustment of chiropractic pelvis 2 times a week for 4 weeks, the other group who didn't take any action. Results. As a result, center of body of experiment group wasn't improved relations between left and right statistically. But the relations between front and back of center of body increased statistically, cross analysis relations between short leg and center of body increased statistically. Conclusions. As a conclusion, experiment group with the front of center of body was improved 12.88% average of center of body. Experiment group with back of center of body was improved 13.84% average of center of body. This result come to the conclusion that chiropractic pelvis adjustment help the front and back of body balance.