• Korean Journal of Remote Sensing
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• v.25 no.3
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• pp.271-285
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• 2009

Multi-temporal satellite imagery can be changed into a transform image that emphasizes the changed area only through the application of various change detection techniques. From the transform image, an automated change detection model calculates the optimal threshold value for classifying the changed and unchanged areas. However, the model can cause undesirable results when the histogram of the transform image is unbalanced. This is because the model uses a single threshold value in which the sign is either positive or negative and its value is constant (e.g. -1, 1), regardless of the imbalance between changed pixels. This paper proposes an advanced method that can improve accuracy by applying separate threshold values according to the increased or decreased range of the changed pixels. It applies multiple threshold values based on the cumulative producer's and user's accuracies in the automated binary change detection model, and the analyst can automatically extract more accurate optimal threshold values. Multi-temporal IKONOS satellite imagery for the Daejeon area was used to test the proposed method. A total of 16 transformation results were applied to the two study sites, and optimal threshold values were determined using accuracy assessment curves. The experiment showed that the accuracy of most transform images is improved by applying multiple threshold values. The proposed method is expected to be used in various study fields, such as detection of illegal urban building, detection of the damaged area in a disaster, etc.

• Journal of Acupuncture Research
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• v.40 no.3
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• pp.252-264
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• 2023

Background: The primary aim of this study is to statistically analyze and compare the difference in treatment outcomes based on the frequency and duration of acupotomy treatment for lumbar disk herniation. Methods: The evaluation of efficacy and safety involved using visual analog scale (VAS), numeric rating scale (NRS), Roland Morris disability questionnaire (RMDQ), EuroQol 5-dimention (EQ-5D), and similar parameters. This was achieved through the establishment of a comparable cohort using propensity score matching. Group A comprised 46 patients who underwent 4 sessions of acupotomy treatment for 2 weeks, while Group B consisted of 15 patients who received 6 acupotomy sessions for 3 weeks. Results: For Group A, the average amount of change in VAS values at weeks 4 and 6 was significantly decreased. However, the average amount of change in RMDQ values was not significant. Notably, the average amount of change of EQ-5D values at week 6 increased significantly. As for Group B, the average amount of change of NRS values in weeks 2 and 3 was significantly decreased. Conversely, the average amount of change in RMDQ and EQ-5D values was not significant. In comparing the 2 groups at the final follow-up, the average amount of change in all evaluation values was not significant. Further, no significant interaction effect was observed in the changes over time in all evaluation values between the 2 groups. Conclusion: This study establishes that there was no statistically significant difference in pain reduction, functional impairment, and quality of life improvement between 2 group.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.4
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• pp.405-435
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• 2019

Despite the recent emphasis on value research in mathematics education along with the significance of values from a new perspective, there has been a lack of research on the values perceived by teachers and students in Korea. This paper analyzes how fifth-grade students would perceive the values of a master teacher with expertise in elementary mathematics education after her teaching of mathematics and whether their values on mathematics learning would change. According to the study, the students recognized that the master teacher valued understanding, preview-review, picture, problem, and reason in mathematics learning. Among these, the value of understanding was perceived as the core value. An analysis of the students' values on general mathematics learning and personal mathematics learning showed that preview and review were the most important before and after the master teachers' teaching. An analysis of the changes in the values of students showed the greatest change in the value of understanding. Instead of accepting the values of the master teacher as it were, students actively reconstructed and maintained them. Based on these results, this paper has drawn implications regarding the consideration of students' values in mathematics learning.

• Journal of the Korean Society of Costume
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• v.53 no.8
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• pp.53-63
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• 2003

Under the social conditions that an understanding of a men change socially and men's interests in their appearances are on the increase, this research intends to study and analyze the changes of people's sensibility of values on ads for men's cosmetics, which is said to be performed the social, cultural function reflecting the social consciousness, the value and the idea creating a new one. The documents for the research was sindonga. The documents were analyzed quantitatively in regard of contents of a linguistic expression and a visual expression showing on advertisements for man's cosmetics, a time series analysis. As a result of analyzing the consumption value through headline of an ad, the emotional value took the highest percentage extending whole periods. Beside emotional value, a time series analysis showed that social values appeared to the major themes in the 1970s, and functional values was important themes in 1980s, and the social values and functional values appeared equally during 1990-2002.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.1-1
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• 1995

An attempt was made to study the subdivision of Korea by the annual amount and the annual change pattern of monthly precipitation days(that is one of the important elements of the precipitation characteristics), using the mean values for the years 1961-1990 at the 68 stations. The amplitudes of annual change were normalized and using these values, the principal component analysis was applied to determine the annual change patterns. The results show that they are expressed by the combinations of the three change patterns in almost whole regions of Korea. As a result,the annual change pattern of precipitation days in Korea is classified into 8 types from A to e,in detail, 36 types from A0 to e$\circled2$.And regional division of precipitation days in Korea is divided into 13 regions from I a to IIIC,into detail, 41 regions from I no to IIICl.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.387-402
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• 1995

An attempt was made to study the subdivision of Korea by the annual amount and the annual change pattern of monthly precipitation days(that is one of the important elements of the precipitation characteristics), using the mean values for the years 1961-1990 at the 68 stations. The amplitudes of annual change were normalized and using these values, the principal component analysis was applied to determine the annual change patterns. The results show that they are expressed by the combinations of the three change patterns in almost whole regions of Korea. As a result, the annual change pattern of precipitation days in Korea is classified into 8 types from A to e, in detail, 36 types from A0 to e$\circled2$.And regional division of precipitation days in Korea is divided into 13 regions from I a to IIIC, into detail, 41 regions from I no to IIICl.

• Journal of the Korean Society of Costume
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• v.51 no.3
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• pp.141-153
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• 2001

The Purpose of this research is to compare the feminine modesties expressed in the clothes of women's college students in 1980s and 1990s, and to find out the social cause of the change of modesty by reference data. Korean women's college students in 1980s considered feminine modesty very important in the selection of clothes but students in 1990's had quite different attitudes. The major cause of this change may be due to the fact that the traditional conservative values in clothes were diminished in 1990's. The main cause of different values in 1980s and 1990s is the rapid social change of korean society in this Period. The concrete factors of changes were the change of authoritarian aesthetic values and the Positive orientation to diversity individuality sensibility and sexuality.

• The Journal of Information Systems
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• v.14 no.3
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• pp.117-122
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• 2005

This paper presents a method for detecting scene changes in video sequences, in which the $chi^{2}$-test is modified by imposing weights according to NTSC standard. To automatically determine threshold values for scene change detection, the proposed method utilizes the frame differences that are obtained by the weighted $chi^{2}$-test. In the first step, the mean and the standard deviation of the difference values are calculated, and then, we subtract the mean difference value from each difference value. In the next step, the same process is performed on the remained difference values, mean-subtracted frame differences, until the stopping criterion is satisfied. Finally, the threshold value for scene change detection is determined by the proposed automatic threshold estimation algorithm. The proposed method is tested on various video sources and, in the experimental results, it is shown that the proposed method is reliably estimates the thresholds and detects scene changes.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.736-744
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• 2005

Statement of problem. Initial stability of implant is an important factor for predicting osseointegration. It requires a rapid, non-invasive, user-friendly technique to frequently assess the implant stability and the degree of osseointegration. Purpose. The aim of this study was to evaluate the correlation between the resonance frequency analysis (RFA) and the radiographic method for peri-implant bone change under in vitro conditions. Material and Method. Twenty implants of 3.75 mm in diameter(Neoplant, Neobiotech, Korea) were used. To simulate peri-implant bone change, 2 mm-deep $45^{\circ}$ range horizontal defect and 2 mm-deep $90^{\circ}$ range horizontal defect area were serially prepared perpendicular to the X-ray beam after conventional implant insertion. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of implants and direct digital image was obtained. ISQ values and gray values inside threads were measured before and after peri-implant bone defect preparation. Results. Within a limitation of this study, ISQ value of resonance frequency analysis was changed according to peri-implant bone change (p<0.05) and gray value of radiographic method was changed according to peri-implant bone change (p<0.05). There was no correlation between the ISQ value and the gray value for peri-implant bone change (p>0.05). But, in horizontal defect condition, relatively positive correlation were between ISQ and gray values(r=0.663). Conclusion. This results provided a possibility that peri-implant bone change may be evaluated by both RFA and radiographic method.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.739-747
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• 2021

This study examined the measurement conditions of the texture profile analysis (TPA) experiments that are typically used to measure the physical properties of sausage. As the measurement conditions (compression ratio and cross-head speed) were changed, the significant differences between the values of textural parameters (hardness, adhesiveness, springiness, cohesiveness, chewiness) of samples changed. Furthermore, among the measurement conditions, there was more variation in the significant difference between the value of samples due to a change in the compression ratio than due to a change in the cross-head speed. The highest variation in significant difference was observed between the values of cohesiveness of samples due to changes in measurement conditions, whereas the lowest variation in significant difference was observed between the values of springiness of samples due to change in measurement conditions. Therefore, it is desirable to provide a clear basis for setting specific measurement conditions for TPA test, since significant differences in the values of textural parameters of samples were caused by differences in cross-head speed or compression ratio, not by a difference in samples, when analyzing the cohesiveness of sausage, especially.