• Fashion & Textile Research Journal
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• v.4 no.1
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• pp.71-78
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• 2002

The purpose of this study was to classify body types of 800 female junior and high school students based on factor analysis, cluster analysis, and correspondence analysis of 15 photometric measurements of the subjects' lateral body lines. The results are as follows: The skeleton structure, which was represented the back bending by the photometric measurement, was already formed at age of 12 or 13, while the cervical skeleton, the size and inclination of the shoulder, and the degree of the lateral inclination of the upper body and the buttocks continued to grow by the age of 16. A factor analysis of the photometric measurement resulted in the sampling which determined the degree of the back bending, front-bust angle, and lateral view as well as the sampling whose factor represented the cervical inclination. A cluster analysis of the photometric measurement resulted in the four types of classification: Type 1, the straight type comprising 13.3% of the whole population; Type 2, the bent-forward type comprising 39.5%; Type 3, the lean-back type comprising 27.4%; and Type 4, the swayback type comprising 19.1%. Accordingly, the bent-forward type was found to be the dominant type among the four lateral body types.

• Journal of the Korean Geotechnical Society
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• v.21 no.3
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• pp.109-118
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• 2005

It is a very difficult task to estimate engineering properties of the ground when designing underground structures, especially in tunnelling. Therefore, a feed-back system to combine the data measured in construction field with priorly estimated information at the design stage is necessary. In this paper, 3-dimensional back-analysis in tunnelling, to which only relative convergence is applied as input values, is carried out to estimate the optimum geotechnical parameters. For this purpose, the Extended Bayesian Method (EBM), which appropriately combines the objective information with the subjective one, is applied to optimize engineering parameters and 3-dimensional numerical analysis is carried out to predict a trend of relative convergence occurrence. The data measured from two tunnelling sites are used to verify the applicability of the proposed back-analysis technique. from the results of analysis, the proposed back-analysis technique is verified.

• Journal of the Ergonomics Society of Korea
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• v.16 no.3
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• pp.37-48
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• 1997

It is very common for women wear shoes with a high heel. It has been known that the high heel could disfigure the foot shape and cause various joint problems including back pain. However, few quantitative studies have been conducted. Therefore, in this study, the low back muscle has been investigated in order to find fatifue effect due to different heights of the heel. In particular, 0, 4, 6 and 8cm heel and two different shapes of heel have been used for an experiment. Ten healthy female subjects volunteered for the study. Isometric Trunk Exertion Frame(ITEF) and Electromyography were used to measure tha Median Frequency via Spectral analysis. The results indicated that the heel height significantly affected the local muscle fatigue of the back. After post hoc analysis, it was found that a proper heel height ougth to be lower than 5cm not to have severely fatigued back muscle after a casual walk for an hour. Such results could be applies to female industrial workers in order to prevent a cumulative trauma disorder of the back, and also to design a female dress shoes minimizing low back fatigue.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.18-26
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• 2004

Back-gated silicon-on-insulator MOSFET -a threshold-voltage adjustable device-employs a constant back-gate potential to terminate source-drain electric fields and to provide carrier confinement in the channel. This suppresses shortchannel effects of nano-scale and of high drain biases, while allowing a means to threshold voltage control. We report here a theoretical analysis of this geometry to identify its natural length scales, and correlate the theoretical results with experimental device measurements. We also analyze experimental electrical characteristics for misaligned back-gate geometries to evaluate the influence on transport behavior from the device electrostatics due to the structure and position of the back-gate. The backgate structure also operates as a floating-gate nonvolatile memory (NVRAM) when the back-gate is floating. We summarize experimental and theoretical results that show the nano-scale scaling advantages of this structure over the traditional front floating-gate NVRAM.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.310-315
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• 2000

We analyzed thermal stress of the STS VOD ladle by the variation of material property of refractory, and determined the location of back filler using FE analysis. Thermal distribution of refractory of ladle between hot face and back face were decreased by the increasing the thermal conductivity, and thermal stress of refractory were decreased about 2 to 4 times with the decreasing the young's modulus coefficients. Back filler, which is constructed to absorb the thermal expansion of dolomite refractory, has relatively low thermal conductivity. Inner side of refractory of ladle maintained high temperature, but temperature of outer side of ladle decreased low. Consequently, inner expansion and outer contraction were appeared. and thermal stress were increased, so thermal stress by the construction of back filler were increased.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.147-179
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• 2002

The important role of observational method in geotechnical engineering are emphasized together with the direction of future development, concerning successful application of the technique on the site investigation, design and feed back at various construction stages. Case histories on the application of feed back are introduced in order to achieve the most economical and reliable construction for tunnel, rock slope and deep excavations through feed back system at design and construction stages. Also the limitations and advantages of the observational method and the role of feed back system are discussed for construction of tunnel, rock slope and deep excavation in hard ground such as layered ground conditions including weathered, soft and hard rocks.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.131-142
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• 2009

Geosynthetic reinforced soil walls are well recognized alternatives to conventional retaining walls due to many advantages in terms of ease of construction, economy, and aesthetics, among others. In recent years, the use of back-to-back (BTB) geosynthetic reinforced soil walls has been increasing for roadway and railway construction. However, there are insufficient studies concerning the behavior of BTB type geosynthetic reinforced soil walls. In this study a series of finite element analysis were performed for BTB walls with various wall geometry and reinforcement distribution. The results were then analyzed to relate the wall geometry and reinforcement distribution and the performance of BTB walls. Optimum reinforcement pattern was also investigated.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.37-52
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• 2022

Purpose : The purpose of this meta-analysis was to evaluate the effects of electrical stimulation on patients with non-specific low back pain. Methods : Domestic databases were gathered from studies that conducted clinical trials associated with electrical stimulation and its impact on pain of non-specific low back patients. A total of 681 studies were identified, with 12 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, outcome, and study design (PICO-SD). The search outcomes were items associated with low back pain. Cochrane risk of bias 2 (RoB 2) was used to evaluate the quality of 12 randomized controlled trials. Effect sizes (Hedges's g) in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publication bias. Cumulative meta-analysis and sensitivity analysis were conducted to analyze the effect according to the sample size and the consistency of the effect size. Results : The following factors had a large overall effect size (Hedges's g=1.28, 95 % CI=.20~2.36) involving electrical stimulation on non-specific low back pain. The subgroup analysis all showed a statistical difference in the types of study design, electrical stimulation, and assessment tool. No statistically significant difference was found in the meta-regression analysis. Publican bias was found in the data. Conclusion : The findings in this study indicate that electrical stimulation interventions have a positive effect on patients with non-specific low back pain. However, due to the low quality of studies and publication bias, the results of our study should be interpreted cautiously.

• PNF and Movement
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• v.17 no.1
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• pp.157-166
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• 2019

Purpose: This study compares and examines the effects of proprioceptive neuromuscular facilitation (PNF) on patients with chronic low back pain through systematic literature review and meta-analysis. Methods: Domestic literature was searched with combinations of keywords including "proprioceptive neuromuscular facilitation," "PNF," "back pain," and "low back pain" using the Research Information Sharing Service (RISS), Korean Studies Information Service System (KISS), and Korean Medical Database (KMbase). Six studies (n=148) were finally included in the analysis through a selection and exclusion process. The quality of the studies was evaluated using the PEDro scale. Results: According to the meta-analysis results, the low back pains of the PNF group and the contrast group showed a standardized mean difference (SMD) of 2.21 (95% CI: -3.35, -1.07, p=0.01, $I^2=83%$) after intervention. Thus, the PNF group showed a statistically significant decrease in low back pain compared with the control group. In addition, the SMDs of the Oswestry Disability Index (ODI), lung function, and the Roland and Morris Disability Questionnaire (RMDQ) were -1.34 (95% CI: -1.88, -0.79, p<0.01, $I^2=35%$), 1.14 (95% CI: 0.49, 1.79, p=0.01, $I^2=0%$), and -1.59 (95% CI: -2.56, -0.62, p=0.01, $I^2=46%$), respectively. Thus, the PNF group showed statistically significant differences from the control group. Conclusion: At present, there is some limit to obtaining definite results about effect sizes because there are relatively few randomized controlled experiments that analyze the effects of PNF exercise in patients with chronic low back pain. Therefore, continuous efforts should be made to conduct randomized clinical trials and long-term efficacy studies in the future.

• Journal of Preventive Medicine and Public Health
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• v.29 no.2 s.53
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• pp.347-357
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• 1996

Although occupational low back pain accounts for $20\sim40%$ of all occupational illness and injury, there are limited numbers of studies regarding the effectiveness of back school program. The objective of this study was to evaluate the economic benefit of back school program for early return to work of occupational low back pain patients in the current occupational injury compensation and management system. The cost-benefit analysis in this study was conducted to evaluate the relative magnitude of benefit to cost. The total cost was estimated by calculating the value of components in back school program according to governmental budget protocol. The back school program was consisted of three major approaches, pain center, work-hardening program and funcional restoration program and each of components had various facilities and experts. The total amount of cost was estimated as 250,866,220 won per year. The most promising type of back school program were quite intensive (a 3 to 5-week stay in a specialized center), therefore, if we adopted the 5-week stay course, 10 courses could be held in a year. Following to the medical act, 20 patients per doctor could participate in a each course, ie, total 200 patients in a year. As a result, we could estimate the cost of 1,254,331 won a patient. We estimated the benefit by using data of a few local labor offices about average medical treatment beneficiary and off-duty beneficiary of 46 occupational low back pain patients in 1994. Ullman and Larsson (1977) mentioned that the group of chronic low back pain patients who participated in back school program needed less time to recover by 48.4% of beneficiary duration. And in the trying to estimate the benefit, we asked 10 rehabilitation board certificate doctors about reduction proportion of treatment cost by introducing back school program. The answered reduction proportions were in the range of $30\sim45%$, average 39%. As a final result, we could see that the introduction of back school program in treatment of chronic occupational low back pain patients could produce the benefit to cost ratio as 3.90 and 6.28. And we could conclude that the introduction of back school program was beneficial to current occupational injury compensation and management system.