• Proceedings of the Korean Society for Language and Information Conference
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• 1995.02a
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• pp.121-126
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• 1995

A new method for Chinese word segmentation named Conditional F'||'&'||'BMM (Forward and Backward Maximal Matching) which incorporates both bigram statistics (ie., mutual infonllation and difference of t-test between Chinese characters) and linguistic rules for ambiguity resolution is proposed in this paper The key characteristics of this model are the use of: (i) statistics which can be automatically derived from any raw corpus, (ii) a rule base for disambiguation with consistency and controlled size to be built up in a systematic way.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.29-33
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• 2005

We have developed an optical pickup head for blu-ray disc. We have adopted a liquid crystal panel to compensate thickness difference of cover layer. By disposing DVD/CD compatible objective inside the BD objective in disc radial direction, we could realize a backward compatibility. Furthermore we have inserted a polarization diffractive optical element to reduce the influence from the other layer in BD dual layer.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.4
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• pp.342-348
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• 2003

Ultrasonic backscattering profiles of the Zr plates(with a thickness of 1.32mm) with/without Be-Zr alloy layer(with a thickness of $100{\mu}m$) were measured at various incidence positions to evaluate the characteristics of Be diffusion layer. Four principal subprofiles were observed in the backward ultrasound radiated from leaky Lamb waves. The angles and the intensities of the subprofile peaks decreased by the stiffening effect of Be layer. Generation and change of the subprofiles were explained by the acoustical property, collective group velocity and leaky factor difference of the plates under consideration. Backward radiation subprofiles turned out to be an useful method for evaluating thin diffusion layers on plates.

• Journal of the Korean Regional Science Association
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• v.31 no.4
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• pp.71-90
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• 2015

This article aims to explore the performance evaluation framework for assessing the contribution of national research and development(R&D) program to productivity growth. The key idea starts with the development of methodology for evaluating the returns to R&D. The method of this study is based on the comparison of productivity growth between different periods, not cross-sectional approach with one period. In this context, backward effect and forward effect are operationally defined as a measurement for contributions of R&D in this paper. The analysis results gives that the backward effect of R&D is greater than the forward effect, while the difference was especially evident with the case of sales variable, not operating profit variable.

• Journal of The Korean Association For Science Education
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• v.8 no.1
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• pp.43-55
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• 1988

This study intended to find the differences between expert's and novice's thinking processes when they solve physics problems. Five physics professors and twenty sophomore students in a physics department were participated in the study. The researcher investigated their thinking processes in solving three physics problems on NEWTON's law of motion. The researcher accepted so called "Thinking Aloud" method. The thinking processes were recorded and transfered into protocols. The protocols were analysised by problem solving process coding system which was developed by the researcher on the basis of Larkin's problem solving process model. The results were as follows: (1) There was no difference of time required in solving physics problem of low difficulty between expert and novices; but, it takes 1.5 times longer for novices than experts in solving physics problems which difficulties are high and average. (2) Novices used working forward strategy and working backward strategy at the similiar rate in solving physics problems which difficulties were average and low. while Novices mo mostly used working backward strategy in solving physic problems which difficulty was high. Experts mostly used working forward strategy in solving physics problems whose difficulties was average and low, however experts used working forward strategy and working backward strategy at the similiar rate in solving physics problem which difficulty was high. (3) Novices usually wrote only a few information on the diagram of figure they drawn, on the other hand experts usually wrote almost all the information which are necessary for solving the problems. (4) Experts spent much time in understand the problem and evaluation stage than novices did, however experts spent less time in plan stage than novices did. (5) Physics problems are solved in sequence of understanding the problem, plan, carrying out the plan, and evaluation steps regardless of problem difficulty.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.25-33
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• 2018

Piping is one of the most frequently occurring collapse type of a levee, and is often caused by roofing (backward erosion piping) at the ground-structure interface. Roofing is generally evaluated using creep ratio. However, creep ratio does not take into account the characteristics of the ground-structure interface. In this study, the roofing risk was investigated by using model test and numerical analysis considering the ground-structure interface characteristics. In the model test, it was confirmed that the piping potential decreased as the interface roughness increased, and this was applied to the numerical analysis. Existing numerical methods can not adequately simulate the particle behavior at the ground-structure interface because only the water level difference is considered. In this paper, particle behavior at the interface was investigated by performing seepage analysis and then, carrying out particle analysis technique simulating the boundary condition of the ground-structure interface. Analysis results have shown that the roofing resistance decreases as the ground-structure interface roughness decreases.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.2
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• pp.235-246
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• 2011

Purpose: The aim of this study is to compare and assess the effects of lumbar stabilization exercise on the balance ability of young college studets with low back pain after having performed spinal stabilization exercise by using 3-dimensional air-balance system and gym ball. Methods: The subjects of this study were 34 low back patients in their early twenties. They were divided into two groups: 3-dimensional lumbar stabilization exercise group(N=17) and gym ball lumbar stabilization exercise group(N=17). The period of the intervention was for five weeks. VAS(Visual Analogue Scale) for pain test, ODI(Oswestry Disability Index) for ADL limitation test, Tetrax system for static balance test, and Air-balance system 3D for dynamic balance test were used as evaluation tools for this study. Results: Pain showed significant decrease in both groups after having performed the experiment, but ADL limitation of the groups did not show any remarkable difference between before and after the experiment. Dynamic balance ability in the 8-directional angle comparison test significantly increased in all directions except for the backward, left-backward, and right-backward directions. As for dynamic balance ability in the 8-directional postural test, 3D exercise group showed statistically significant reduction in every direction while gym ball exercise group did not(p<.05). However, when it comes to static balance ability in the weight distribution and stability test, there was not significantly change between pre and post test in both groups. Conclusion: This study shows 3-dimensional lumbar stabilization exercise is more effective in the lumbar stabilization of coordinated movement than gym ball exercise, which may imply that 3D air-balance system can be used for the therapeutic treatment of body imbalance for patients with low back pain.

• Korean Journal of Biological Psychiatry
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• v.17 no.2
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• pp.70-78
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• 2010

Objectives : This study investigated the differences of working memory among the subtypes of ADHD. Methods : Eighty-one children and adolescents with ADHD and thirty normal controls were recruited. Children with any cognitive disorders and low intelligence were excluded. In order to evaluate the verbal and visuospatial working memory, Digit span and Finger windows tasks were measured, respectively. Performances on these measures between children with ADHD and controls were compared. Further, performances among the groups of ADHD predominantly inattentive(ADHD-IA)(n=40), predominantly hyperactive-impulsive(ADHD-HI)(n= 10), and combined type(ADHD-C)(n=31), were compared. Results : Scores of Finger windows forward task were lower in the ADHD group as compared to the control group, whereas, the Digit span forward showed no difference. Both scores of Digit span backward and Finger windows backward task were lower in the ADHD group than the controls. Children with ADHD-IA performed poorer than children with ADHD-C on the Finger windows backward task. Conclusion : The results of this study showed that children with ADHD have deficits in spatial short-term memory and verbal and visuospatial working memory when compared to normal children. The deficits were evident in children with ADHD-IA subtype and in particular, performance on the visuospatial working memory task in this group was poorer than the ADHD-C group.

• PNF and Movement
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• v.7 no.4
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• pp.31-36
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• 2009

Many daily activities require people to complete a motor task while walking. Substantial gait decrements during simultaneous attention to a variety of cognitive tasks have been shown by a group of severely injured neurological patients of mixed etiology. And previous studies have shown that the attentional load of a walking-associated task increased with its level of difficulty. The purpose of this study was to analyze subjects' gait changes are affected by the effects of arithmetic task difficulty and performance level. Participants performed a walking task alone, three different Arithmetic tasks while seated, and among them, two kinds of the simillar Arithmetic tasks in combination with walking. Reaction time and accuracy were recorded for two of the Arithmetic tasks. The mean values of the gait were measured using a Timed Up and Go test among 11 with post-stroke patients while walking with and without forward counting (WFC) and backward counting(WBC).There was significant Arithmetic Task Difficulty level between the 10-forward counting task condition(FC) and the 10-backward counting task condition(BC)(p=0.008). The mean values of T.U.G time were significantly higher under backward counting dual-task condition than during a simple walking task(p=0.009) and WFC(p=0.009). The change in T.U.G time during WFC was higher when compared with the change during a simple walking, but there was no significant difference (p=0.246). This study suggesting that a high interference could be linked with a high level of difficulty, whereas adaptive task enabled participants to perfectly share their attention between two concurrent tasks. Future research should determine whether dual task training can reduce gait decrements in dual task situations in people after stroke. And the dual-task-based exercise program is feasible and beneficial for improving walking ability in subjects with stroke.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.135-144
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• 2021

Purpose : The purpose of this study was to investigate the effect of 2 weeks of backward walking exercise (BWE) on cervical angle and gait parameters in college students with forward head posture. Methods : Fifteen subjects participated in the experiment. All the participants had a craniovertebral angle (CVA) of 55 degrees or less. The purpose of the study was explained to all the subjects prior to participation, and volunteered to take part in the study. A camera capable of taking pictures of the lateral plane was installed at a distance of 1.5 meters from each subject. Images of forward head posture were obtained before and after performing the BWE, and the CVA and craniorotational angle (CRA) were compared pre- versus post exercise. Foot pressure and gait parameters (step length of left and right, stride length, stance of left and right, swing of left and right, step time of left and right, and stride time) were measured using a rehabilitation treadmill. The subjects performed the BWE for 2 weeks. The exercise program consisted of a 5-minute warm-up exercise, 20-minute main exercise, and 5-minute cool-down exercise. In the main exercise, the treadmill speed was set to 2.4 km/h in the first week and 3.4 km/h in the second week. A paired t test was used to compare the CVA and CRA and gait parameters before and after the exercise. Results : Comparison of the CVA and CRA before and after the BWE revealed a significant difference post exercise, with a marked improvement in forward head posture after the exercise (p<.05). Conclusion : Based on the results of this study, the BWE is considered to be an effective exercise for the forward head posture. Also, additional research is needed to shed light on the impact of the BWE on gait parameters.