• Atmosphere
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• v.24 no.2
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• Transactions of Materials Processing
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• v.21 no.3
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• pp.160-163
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• 2012

In this paper, a new approach to finite element analysis for tube swaging is presented. An analysis model is developed with emphasis on the pusher that imposes back pressure in order to keep the workpiece from slipping along the die-workpiece interface especially when tapered dies are used. A rigid-plastic finite element method is employed. The approach is to simulate the tube swaging process and the results are compared quantitatively with predictions, showing close agreement with each other.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.173-191
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• 2002

The purpose of this study was defined efficient throw motion pattern to obtain the quantitative data and to achieve successful bowling through kinetic - kinematic variables on the throw motion. Subject of group composed of three groups : Higher bowlers who are two representative bowlers with 200 average points and one pro-bowler. Middle bowlers who are three common persons with 170 average points. Lower bowler who are three common persons with 150 average points. Motion analysis on throw motion in three groups respectively has been made through three-dimension cinematography using DLT method. Two high-speed video camera at operating 180 frame per secondary. One-way ANOVA has been used to define variable relations. Analyzed result and conclusion are the following : The displacement of back of the hand must have wider difference of each right-left displacement to increase the spin of the ball. In high bowlers group, difference between the front-rear position of back of the hand in case of success and that in case of failure in follow throw is 0.17m. That is to say, momentum in case of success come to increase greatly, compared with that in case of failure. To increase the spin of the ball, the potential difference should be narrower in follow through. In case of the high bowlers, the velocity of the front-rear direction of the back of the hand has been the fastest both in release and follow through, compared with those in other groups, which has contributed to increasing the spin force of the ball. The orders in the resultant velocity of the back of the hand has shown the this : the finger tip$\rightarrow$the back of the hand$\rightarrow$wrist.These orders made the proximal segment support the distal segment. The distal segment has provided the condition to accelerate the velocity. In case of failure, the suddenly increased velocity has caused the failure in the follow through. Acutely flexing the angle of the back of the hand has contributed to lifting to increase the spin of the ball.

• Journal of Korean Physical Therapy Science
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• v.29 no.2
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• pp.38-47
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• 2022

Background: The purpose of this study was to investigate the effect of the combined application of manipulation and stabilization exercises on pain and spinal curvature in patients with chronic back pain. Design: Randomized controlled trial Methods: The research subjects included 24 women in their 40s and 50s who have chronic back pain. The sample was evenly divided into an experimental group, which received the combined application of manipulation and stabilization exercises, and a control group, which received stabilization exercises only. The 30-minute intervention was applied five times a week for eight weeks. A bivariate repeated measures analysis of variances was conducted to identify the differences between the two groups before the experiment, after the fourth week, and at the end of the eight-week experiment. The level of statistical significance was set at.05. This analysis examined the within-group changes and the between-group changes using a paired t-test and an independent t-test, respectively. Results: Changes in pain differed significantly depending on the time of the measurement, the interaction between the time of the measurement and each group, and between the two groups (p<.05). Changes in the curvature of the bones of the neck, the bones of the back, and the lumbar vertebrae differed significantly depending on the time of the measurement and the interaction between the time of the measurement and each group (p<.05). Conclusion: The combined application of manipulation and stabilization exercises demonstrated a positive effect on changes in pain and spinal curvature, and the method is expected to be a useful intervention for reducing pain and improving spinal curvature in patients with back pain.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.503-512
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• 1990

In this study, a penalty method effective for the case that has no snap-back phenomenon, is proposed and an adaptive method which choose the penalty method or Riks' type method, is suggested for the case of snap-back problem. And for the case that loads are applied to one or more points of a structure, the Riks' method is applied in general, but under certain condition choice of new incremental load parameter is suggested to accelerate the convergence rate. Finally, for the case that displacements of a structure are controlled at one or more points Riks' type method is proposed. In this case, the proposed method is applied in general but under certain condition it is recommended to choose other incremental displacement parameter to eliminate probable divergence. Five examples are analysed and compared with the result of published literature.

• Journal of Acupuncture Research
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• v.39 no.3
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• pp.170-181
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• 2022

This review evaluated the efficacy of electroacupuncture (EA) for chronic fatigue syndrome. Randomized controlled trials (RCTs) using EA as an intervention for patients with chronic fatigue syndrome were identified in 6 databases (PUBMED, EMBASE, CNKI, J-STAGE, KMBASE, OASIS). Fatigue indicators were used as the primary outcome measures. The quality-of-life index, efficiency rate, and level of pain were used as secondary outcome measures. There were 408 patients from seven RCTs included in this study. Meta-analysis showed that EA was significantly associated with fatigue relief compared with the control group (n = 141 SMD = -1.55, 95% CI; -2.58 - -0.52, p = 0.003, I² = 92%). In addition, EA had a statistically significant improvement in quality of life compared with the control group (n = 176, SMD = -2.29, 95% CI; -3.68 - -0.90, p = 0.001, I² = 96%). One study reported ten cases of bleeding, however, no serious adverse events were reported in any of the included studies. This review determined that EA may have a greater clinical effect than the control group for fatigue relief and improved quality of life. However, there were several risks of bias identified. Not all of the RCTs accurately reported the research method, all studies were conducted in 1 country (China), and the number of studies included were small.

• Fashion & Textile Research Journal
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• v.2 no.4
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• pp.353-359
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• 2000

The purpose of this study was to develop the jacket pattern drafting method for Korean middle-aged women. The study was composed as follows : 1. Body measurement and statistical analysis : Two hundreds and forty four middle-aged women between the ages of forty five and fifty nine were measured on 52 items. 2. Development of new jacket pattern drafting method : Measurement items necessary to draft new jacket pattern were back waist length, bust girth, waist girth, hip girth, back interscye breadth, front interscye breadth, neck base girth, nipple length, nipple to nipple breadth, 1/2 posterior shoulder length and sleeve length. Basic jackets constructed from the experimental patterns were examined through the fitting test. 3. Evaluation of the new pattern drafting method : The sensory evaluations for appearance and comfort were applied to evaluate the new jacket pattern by comparing it with one of the conventional jacket patterns (Lee Hyung-Suk's). According to the result of sensory evaluation, the new jacket pattern was more positive.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.620-623
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• 2000

A very simple control approach using neural network for the robust position control of a Permanent Magnet Synchronous Motor(PMSM) is presented The linear quadratic controller plus feedforward neural network is employed to obtain the robust PMSM system approximately linearized using field-orientation method for an AC servo. The neural network is trained in on-line phases and this neural network is composed by a fedforward recall and error back-propagation training. Since the total number of nodes are only eight this system can be easily realized by the general microprocessor. During the normal operation the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. And the state space analysis is performed to obtain the state feedback gains systematically. IN addition the robustness is also obtained without affecting overall system response. This method is realized by a floating-point Digital Singal Processor DS1102 Board (TMS320C31) The basic DSP software is used to write C program which is compiled by using ANSI-C style function prototypes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.11
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• pp.1931-1942
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• 1997

A new load/displacement parameter method is developed for the cases that loads are applied to one or more points, and displacements of a structure are controlled at one or more points sinultaneously. The procedure exploits a generalized Riks method, which utilizes load/displacement parameters as scaling factors in order to analyze the post-buckling phenomena including snap-through or snap-back. A convergence characteristic is improved by employing new relaxation factors in incremental displacement parameter, particularly at the region where exhibits severe numerical instability. The improved performance is illustrated by means of numerical example.

• Structural Engineering and Mechanics
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• v.19 no.2
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• pp.153-172
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• 2005

A new load/displacement parameter method is proposed for the simultaneous control of applied loads and structural displacements at one or more points. The procedure is based on a generalized Riks' method, which utilizes load/displacement parameters as scaling factors to analyze post-buckling phenomena including snap-through or snap-back. The convergence characteristics are improved by employing new relaxation factors through an incremental displacement parameter, particularly in a region that exhibits severe numerical instability. The improved performance is illustrated by means of a numerical example.