• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.915-916
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• 2007

There are many equipments for the Short Circuit Test, for example Short Circuit Generator, Induction Motor, Sequence Timer, Exciter, CLR, Back Up Breaker, Making Switch and TRV etc. Especially Back up Breaker and Making Switch are very important equipments to test the short circuit test. A role of a Back up Breaker is to break high-voltage and high-current for short circuit test and a Making Switch should be operated always same speed/time and kept electrical-mechanical characteristics to make the voltage and current of short circuit test. This study introduces to the short circuit test also to kinds, principal movements and compare them of Back up Breaker and Making Switch.

• Journal of Welding and Joining
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• v.13 no.4
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• pp.75-84
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• 1995

In GMA welding of sheet metal, the short circuit metal transfer mdoe is preferred because of its low heat input and capability of bridging the root gap. The molten electrode is transferred to the workpiece during repectitive short circuit in the model. The waveform of welding current or voltage and the frequency of short circuiting are affected by a number of factors including: magnitude of welding current and voltage, root gap, electrode extension, power supply characteristics, and so on. In this study experimental models were proposed, which are able to determine the relationship between the root gap and short circuit frequency and the relationship between the root gap and appropriate welding speed that produces the good quality of back bead without burn through. Using the experimental models, the root gap can be obtained from measuring the short circuit frequency, and then the appropriate weldig speed to the root gap can be determined. Thus a back bead control system was constructed by controlling the welding speed for maintaining the quality of back bead. The developed system has shown the successful capability of back bead control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.894-901
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• 2006

In general, the tension fores of hanger cable in suspension bridges play an important role in evaluating the bridge state. The vibration method, as a conventional one, has been widely applied to estimate the tension fores by using the measured frequencies on hanger cables. However, the vibration method is not applicable to short hanger cables because the frequency of short cables is severely sensitive to the flexural rigidity. Thus, in this study, the tension forces of short hanger cables, of which the length is shorter than 10meters, were estimated through back analysis of the cable frequencies measured from Gwang-An suspension bridge in Korea. Direct approach to rock analysis is adopted using the univariate method among the direct search methods as an optimization technique. The univariate method is able to search the optimal tension forces without regard to the initial ones and has a rapid convergence rate. To verify the feasibility of back analysis, the results from back analysis and vibration method are compared with the design tension forces. From the comparison, it can be inferred that back analysis results are more reasonable agreement with the design tension forces of short hanger cable. Therefore, it is concluded that back analysis applied in this study is an appropriate tool for estimating tension forces of short hanger cables.

• Physical Therapy Korea
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• v.21 no.4
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• pp.56-66
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• 2014

For maintaining adequate psychometric properties when reducing the number of items from an instrument, item level psychometrics is crucial. Strategies such as low item correlation or factor loadings, using classical test theory, have traditionally been advocated. The purpose of this study is to describe the development of a new short form assessing the impact of low back pain on physical activity. Rasch measurement model has been applied to the International Classification of Functioning, Disability and Health Activity Measure (ICF-AM). One hundred and one individuals with low back pain aged 19-89 years (mean age: $48.1{\pm}17.3$) who live in the community were participated in the study. Twenty-seven items of lifting/carrying construct of the ICF-AM were analyzed. Ten items were selected from the construct to create a short form. Item elimination criteria include: 1) high or low mean square (out of the range: .6-1.4 for the fit statistics), 2) similar item calibrations to adjacent items, 3) person separation value, and item-person map for potential gap in person ability continuum. All 10 items of the short form fit to the Rasch model except one item (i.e., carrying toddler on back). Despite its high infit and outfit statistics (1.90/2.17), the item had to be reinstated due to potential gaps at the upper extreme of person ability level. The short form had a slightly better spread of person ability continuum compared to the entire set of item. The created short form separated individuals with low back pain into nearly 4 groups, while the entire set of items separated the individuals into 6 groups. The findings prompted multidimensional models for better explanation of the lifting/carrying domain. The item level psychometrics based on the Rasch model can be useful in developing short forms with rationally retained items.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.139-151
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• 2021

PURPOSE: This study examined the effects of wall-squat with short-foot exercise on pain, dysfunction, and pelvic alignment in chronic low back pain patients. METHODS: Thirty outpatients diagnosed with chronic low back pain and pronated foot were enrolled in this study. The patients were divided randomly into a wall-squat with short-foot exercise group (WS; n = 15) and a normal wall-squat exercise group (NW; n = 15). These groups performed their respective exercises 15 times, for three sets, three times a week over six weeks. The visual analogue scale (VAS) was used to measure the subjects' pain, and the Roland-Morris disability questionnaire (RMDQ) was used to measure the subjects' dysfunction. A navicular drop test (NDT) was used to measure the subjects' arch height. To assess the patients' pelvic alignment, their lordosis, sacral tilt, lumbar width, sacral width, ilium length, and ilium width were measured by X-ray imaging. RESULTS: Both the WS and NW groups exhibited significant decreases in their VAS and RMDQ scores after exercise (p < .05). The WS group exhibited significant increases in their arch height (p < .05). Significant differences in the VAS, sacral tilt, sacral width, and ilium length were observed between the WS and NW groups (p < .05). CONCLUSION: These results suggest that wall-squat exercise is effective in decreasing the level of pain and dysfunction in chronic low back pain patients. In addition, the wall-squat with short-foot exercise is considered more effective in improving the pelvic alignment than without short-foot exercise. This can be an effective method for the non-pharmacological and non-surgical treatment of chronic low back pain

• Physical Therapy Korea
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• v.22 no.3
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• pp.61-70
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• 2015

To develop an effective and efficient measurement system for tracking changes of functional status across two measures, it is essential to integrate information and communicate scores across two measures. The lack of communication between two measures leads to score incompatibility. A potential solution would be the development of a crosswalk table between those measures. Prior to creating a crosswalk table, selecting common items between two measures is critical. By using the Oswestry low back pain disability questionnaire (Oswestry) and a short form measuring disability resulting from low back pain, item level statistics as well as differential item functioning (DIF) using the Rasch measurement were investigated. Eighty-two participants with known group validity were recruited. Based on the application of the Rasch measurement model, item difficulties across the two measures were logically and hierarchically ordered. Ceiling effects for both measures were detected, which were not be able to be effectively measured with the two measures. The DIF analysis across the two measures confirmed that five paired items were found to have DIF and five common items were selected for common items. Although five paired items function differently across the Oswestry and the short form, all items of both measures were well targeted study participants. The common items selected by the Rasch measurement model may be effective when creating a crosswalk table between the Oswestry and the short form.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.2
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• pp.215-231
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• 2023

This study classifies short front long back skirts from the Joseon Dynasty by style type, identifies their formative characteristics based on their external morphological properties and internal composition, and examines their correlation with Korean thought. A literature review and empirical research were conducted for this study. The style of short front long back skirts is classified as inverted "b"-shaped, lower lip, wavy, trapezoid with a raised center hem, or half-circle. As such, this skirt possesses the formative properties of imbalance, variability of shape, intentional three-dimensionality, and confluence. In other words, with an imbalance resulting from the difference in length between the front and back, these skirts are characterized by variability in shape created by intentional three-dimensionality expressed as intentional three-dimensional beauty, the confluence of planes and dimensions, as well as of materials and colors. These properties are correlated with Korean ways of viewing the world. This study contributes to the development of Korean designs.

• Journal of Ocean Engineering and Technology
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• v.16 no.2
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• pp.53-59
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• 2002

This paper shows the experimental results controlling the height of surface and back bead in GMAW by analyzing the unexpected gaps between base metals produced in welding and by controlling welding velocity due to the variation of the gap between base metals in thin-plate welding. The back bead behavior and burn-through in I-type butt joint $CO_2$ welding of thin mild steel are analyzed in the views of short circuit time ratio and short circuit frequency. It is shown through experimental consideration that the short circuit time ratio method is more reasonable than the short circuit frequency method in analyzing the formulation of back bead under changing the gap between base metals. Based on the these results, welding manipulator is designed so as to satisfy the bead height control in real time by measuring the short circuit time ratio. To show the effectiveness of the developed bead formulation control system, the experiment is implemented under two welding conditions such as increasing gap from 0mm to 0.8mm and gradually increasing gap from 0mm to 1.2mm. The experimental results show that the bead formulation can be controlled uniformly in spite of the variation of the gap between base metals.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1054-1062
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• 2011

This study describes the time domain imaging algorithm which can be well applied to short-range UWB(ultra wideband) bistatic radar. In the imaging method of SAR technology, the frequency domain method is well applied to the areas which satisfy far-field condition. However in the near-field environment, the image quality is not good due to phase error. However back-projection method based on time domain is well applied to short-range imaging radar. Meanwhile because its processing time is very long, real time-processing is very difficult. To resolve this problem FFBP(Fast Factorized Back-Projection) was proposed. Using the raw data gathered on field we implemented back-projection and FFBP method. Then image quality and processing time were analyzed using these methods.

• The Journal of Korean Obstetrics and Gynecology
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• v.29 no.3
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• pp.110-120
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• 2016

Objectives: The object of this study is to report a clinical effect of oriental medical treatments with Chuna for acute low back pain during the early stages of pregnancy.Methods: The patient in this case, 31 years-old female was admitted for 1days (20th/June/2016-30th/June/2016) due to the acute low back pain on the 7 weeks of pregnancy. We diagnosed as 挫閃腰痛, 傷筋 (Sprain and strain of lumbar spine) and treated with Chuna therapy and other conservative treatments including acupuncture herbal mixture. And we measured Visual Analog Score (VAS), Oswestry disability index (ODI), McGill pain questionnaire-short form (SF-MPQ).Results: After treatments, Visual Analog Score (VAS), Oswestry disability index (ODI), McGill pain questionnaire-short form (SF-MPQ) were significantly improved in case.Conclusion: Oriental medical treatments with Chuna manual therapy were associated with improvement of acute low back pain during the early stages of pregnancy.