• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.112-118
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• 2023

As technology advances, the need for enhanced preparedness against cyber-attacks becomes an increasingly critical problem. Therefore, it is imperative to consider various circumstances and to prepare for cyber-attack strategic technology. This paper proposes a method to solve network security problems by applying reinforcement learning to cyber-security. In general, traditional static cyber-security methods have difficulty effectively responding to modern dynamic attack patterns. To address this, we implement cyber-attack scenarios such as 'Tiny Alpha' and 'Small Alpha' and evaluate the performance of various reinforcement learning methods using Network Attack Simulator, which is a cyber-attack simulation environment based on the gymnasium (formerly Open AI gym) interface. In addition, we experimented with different RL algorithms such as value-based methods (Q-Learning, Deep-Q-Network, and Double Deep-Q-Network) and policy-based methods (Actor-Critic). As a result, we observed that value-based methods with discrete action spaces consistently outperformed policy-based methods with continuous action spaces, demonstrating a performance difference ranging from a minimum of 20.9% to a maximum of 53.2%. This result shows that the scheme not only suggests opportunities for enhancing cybersecurity strategies, but also indicates potential applications in cyber-security education and system validation across a large number of domains such as military, government, and corporate sectors.

• The Journal of the Acoustical Society of Korea
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• v.29 no.5
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• pp.325-331
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• 2010

Categorical perception has been noted as characteristic properties of linguistic stimuli. In this study, Korean monosyllabic minimal pairs (consonant-vowel-consonant, CVC) were analyzed to understand perception boundaries between clinically confusing words. An efficient scheme has been developed to systematically synthesize temporal transition waveforms (11 steps) from one word to the target word for the pairs of /gom/-/gong/, /non/-/noon/, and /don/-/non/. The corresponding slopes, widths, and non-dominant factors of perception boundaries were analyzed for the total of 40 young normal subjects (20 males and 20 females). Results showed that there were relative pattern differences among confusing monosyllabic minimal pairs under categorical perception. For instance, the vowel difference within CVC pairs led to the lowest boundary performance in this experiment set. Data also indicated the potential application of the overall procedure for evaluating auditory functions and assisting rehabilitation programs.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.2
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• pp.177-197
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• 2007

This study discussed the climbing learning method which studied and practiced by Professor Saito Noboru. This is the learning method which is devised to know not only the relationship of the learning factors but the systemic or structural connection of whole studying contents- affects children's math learning ability through practical class to both the lower and the higher grades. To achieve the purpose of this study, these following issues were set; A. Develop the teaching and learning course of mathematics by applying the climbing learning method. B. Execute the mathematics lesson according to the climbing learning method and analyze the learning achievement. C. Analyze the difference between application of the climbing learning method and that of the learning method by student's level in mathematics. D. Analyze what the climbing learning method gives a shift of the recognition of learning mathematics. In order to accomplish these study issues, we analyzed the text book of math not only for children but also for teachers and developed the teaching and learning course applied the climbing learning method with advice of experts. It was chosen two different homogeneous groups each, third year for lower grade group and fifth year for higher grade group. It was done the experimental group lesson applying the climbing learning method and general lesson for the control group. After then, t-test against independent samples was done depending on the result of the student's assessment(T1, T2). These two groups' students were divided into smaller groups based on result of achievement level regardless of gender. These subgroups were confirmed the difference of learning ability between upper and lower level group. As regarding the result making out grades of faith and attitude for math, t-test was used on independent sample. At the same time, experimental groups were tested using learning attitude with the learning structure chart. Through this study the following results are obtained and the conclusion was drawn. Firstly, although applying the climbing learning method to the lesson does not have significant effect to the lower grade of elementary school student's achievement it has significant influence on the higher grade student's achievement. Second, as a result of analyzing the difference between the climbing learning method and the learning method by student's level in mathematics, it is of no beneficial effect to the lower grade both upper level and lower level. However, it has appreciable effect to the higher grade classes both upper level and low level. Especially, upper level students have higher effect than low level students. Third, climbing learning method does not affect to the faith and attitude of the lower grade students positively, but it has affirmative effect to the higher grade students'. As a result of the survey of the experimental groups which were applied to the climbing loaming method, the lesson by using the learning structure chart proved to be helpful to the both the lower and higher grade. The best advantage of using the learning structure chart, children say, is easily understood whole contents of studying and is useful for review. Furthermore, using the learning structure chart is more efficient compared with previous learning method and is given the successful result to self-directed learning. In conclusion, keeping up with the current of the thought of education, we suggest a scheme as a new teaching method from the constructive learning method which emphasize the self-directed learning.

• Journal of the Korean association of regional geographers
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• v.14 no.3
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• pp.269-278
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• 2008

This research analyzed the effect of lessons with the GIS application as an alternative scheme of teaching and learning of geography in elementary school. Two classes in the third grade at Y elementary school in Andong were selected to conduct lessons on 'The Landscape of My Hometown' from March 6 through June 30, 2006. In the experimental class, the lessons were conducted with the GIS application; while, in a comparative class, the lessons were carried with usual teaching and learning method. To find out the effect of lessons with the GIS application, differences of spatial cognition of students were figured out between groups, and before and after lessons. The difference between the spatial concept development stages and materials on the textbook discouraged students to pursue their learning as well as made them hard to achieve the goals of lessons. The GIS application had been suggested as an alternative teaching and learning method to overcome the difference; however, it has been hard to find any empirical research to verify the effect of the lessons with GIS application in elementary school. The ability of spatial cognition of the third graders at an elementary school was very low as the result of that curricula in the first and second grades dealt with sketch maps as teaching and learning media. The map learning of third grader on the transitional stage would play the critical role to develop the spatial cognition ability in the future. The field study contributing to developing spatial cognition ability would not be conducted at school. It was required to have the alternative learning schemes such as lessons with GIS application. The lessons with GIS application verified effect of GIS application as the alternative method. The GIS application helped students to recognize landmarks, directions and distance effectively as well as reduced the spatial cognition difference among individuals and/or groups.

• The Journal of Engineering Geology
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• v.9 no.2
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• pp.161-176
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• 1999

The objectives of this study are to analyze the changes of geo-surface topography in the Siwha embankment and the Ahsan city area by the image processing of Landsat Thematic Mapper data, and to estimate the reclaimed amount of the exposed tidal flat in the Siwha area using the GIS. False color composite, Tasseled cap, NVDI(normalized difference vegetation index), and supervised classification techniques were used to analyze the distribution of sediments and the aspect of topographical variations caused by artificial human actions. The total amount of the exposed tidal flat was estimated on the basis of the database snch as aerial photography, hydrographic chart, geological map, and scheme drawing in the Siwha area. The possible excavation regions for a seawall were predicted analyzing the supervised classification image of Landsat TM data. Tasseled cap images were used to observe the distribution of sediments. The difference of the NDVI images between spring and summer seasons indicates that deciduous and coniferous forests were distributed over the whole areas. The total fill-volume of the exposed Siwha tidal flat and the fill-volume of the construction planning seawall were calculated as $581,485,354\textrm{m}^3{\;}and{\;}3,387,360\textrm{m}^3$, respectively, from the digital terrain analysis. Daebu Island, Sunkam Island, and the part of Songsan-myeon were chosen as the cut area to make the seawall, and their cut-volumes were estimated as $5,229,576\textrm{m}^3,{\;}79,227,072\textrm{m}^3,{\;}and{\;}47,026,008\textrm{m}^3$, respectively. Therefore, the cut-volume of Daebu Island alone among three areas was sufficient to make the seawall.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.491-507
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• 2000

The purpose of this study was to investigate if there were a significant differences in mandibular position between cephalometric measurements from a centric occlusion tracing compared to those of a acquired centric relation by stabilization splint on malocclusion patient with TMD. 60 malocclusion patients, who had TMD and CO-CR discrepancy beyond normal range, were selected and subdivided into Class I, II, III by Angle's classification and also subdivided into clockwise, straight downward, and counterclockwise group by Jarabak's posterior facial height/anterior facial height ratio. Lateral cephaolmetric radiographs with the mandible in centric occlusion were taken and measured, and for each Patient the stabilization splint with mutually protected occlusal scheme was applied for minimum 3months. After each patient's CO-CR discrepancy was in normal range, lateral cephalometric radiographs were retaken and measured. The comparison of the difference between CO-CR cephalometric measurements in all sample, Class I, II, III groups, and Clockwise, Straight downward, Counterclockwise groups were studied. The finding of this study can be summarized as follows: 1 In all sample, the value of cephalometric measurements was significantly different between CO-CR. The mandible rotated to down and posterior position and the vertical change was greater than the horizontal change (overjet-1.3mm increase, overbite-1.9mm decrease). 2. In Class II malocclusion group, most of the mean difference value between CO-CR is higher than that of the other groups and more measurements was statically significant. 3. In clockwise and counterclockwise group, some of the mean difference value is higher than that of straight downward group and more measurements was statically significant. 4. There ware no measurements that explain centric relation measurements from the type of malocclusion, facial pattern and centric occlusion measurements. Henceforth, it is strongly recommended that stabilization splint therapy for orthodontic treatment on TMD patient should be excuted upon overall facial types prior to orthodontic diagnosis and treatment planning.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.245-254
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• 2006

While orofacial pain or various dental factors are generally considered as the primary cause of unilateral chewing tendency, there exist several studies indicating that dental factors did not affect the preferred chewing side. The aim of this study was to examine difference of occlusal scheme between the subjects with and without chewing side preference. The difference between the chewing and non-chewing sides in the unilateral chewing group was investigated as well. Computerized, T-Scan II system was used for occlusal analysis. 20 subjects for the unilateral chewing group (mean age of $25.25{\pm}2.84$ years) and 20 subjects for the bilateral chewing group (mean age of $27.00{\pm}5.07$ years) were selected by a questionnaire on presence or absence of chewing side preference and those with occlusal problem or pain and/or dysfunction of jaw were excluded. T-Scan recordings were obtained during maximum intercuspation and excursion movement. The number of contact points, relative occlusal force ratio between right and left sides, tooth sliding area and elapsed time throughout the maximum intercuspation were calculated. Elapsed time for excursion was also investigated. The results of this study shows that the unilateral chewing group had the smaller average tooth contact areas compared with those of the bilateral group (p<0.005). In the unilateral chewing group, the contact areas of non-chewing side are smaller than those of chewing side (p<0.005). The contact areas on their preferred sides were not significantly different with those of right or left side of the subjects without chewing side preference. There was no significant difference in the elapsed time during maximum intercuspation and lateral excursion, the sliding areas and relative of right-to-left occlusal force ratio between the two groups. From the results of this study, it is likely that individuals prefer chewing on the side with more contact areas for efficient chewing.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.53-61
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• 2002

Purpose : To determine the optimal scheme of postoperative chemoradiotherapy in rectal cancer by comparing survival, Patterns of failure, toxicities in early and late radiotherapy groups using a Phase III randomized prospective clinical trial. Materials and Methods : From January 1996 to March 1999, 307 patients with curatively resected AJCC stage II and III rectal cancer were assigned randomly to an 'early (151 patients, arm 1)' or a 'late (156 patients, arm II)' and were administered combined chemotherapy (5-FU $375\;mg/m^2/day$, leucovorin $20\;mg/m^2$, IV bolus daily, for 3 days with RT, 5 days without RT, 8 cycles with 4 weeks interval) and radiation therapy (whole pelvis with 45 Gy/25 fractions/5 weeks). Patients of arm I received radiation therapy from day 1 of the first cycle of chemotherapy and those of arm II from day 57 with a third cycle of chemotherapy. The median follow-up period of living patients was 40 months. Results : Of the 307 patients enrolled, fifty patients did not receive scheduled radiation therapy or chemotherapy. The overall survival rate and disease free survival rate at 5 years were $78.3\%\;and\;68.7\%$ in arm I, and $78.4\%\;and\;67.5\%$ in arm II. The local recurrence rate was $6.6\%\;and\;6.4\%$ (p=0.46) in arms I and II, respectively, no significant difference was observed between the distant metastasis rates of the two arms ($23.8\%\;and\;29.5\%$, p=0.16). During radiation therapy, grade 3 diarrhea or more, by the NCI common toxicity criteria, was observed in $63.0\%\;and\;58.2\%$ of the respective arms (p=N.S.), but most were controlled with supportive care. Hematologic toxicity (leukopenia) greater than RTOG grade 2 was found in only $1.3\%\;and\;2.6\%$ of patients in each respective arm. Conclusion : There was no significant difference in survival, patterns of failure or toxicities between the early and late radiation therapy arms. Postoperative adjuvant chemoradiation was found to be a relatively safe treatment but higher compliance is needed.

• Archives of design research
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• v.18 no.4 s.62
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• pp.73-84
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• 2005

The purpose of this study is to analyze the interior color characteristics of elderly housing facilities in Korea. For this purpose, a filed survey was conducted between October 16 and October 25, 2003, visiting 10 elderly housing facilities. A three step analysis of the facilities was involved. First, floor, walls, ceiling, base boards and doors in common spaces were examined for the color scheme using the 'Pantone for Fashion and Home Color Guide' for each room. Measured Pantone numbers were converted to RGB color using 'Chooser 3.0 of Pantone, Inc.' Finally, the conversions were recorded as Munsell numbers. The results are as follows. First, the brightness used in elderly housing facilities ranges from high value to low value while the chroma ranges from the middle chroma to low chroma. The warm colors of Y and YR are mainly used, followed by GY and R. Second, the colors used for elderly housing facilities are found inter-related. For example, the main color in the lobby is also used for corridor and used again in dining room, library, and treatment room. Third, in terms of the color scheme, it is best help the elderly, who generally have lower recognition capability, by highlighting the distinction and attention by using the dearly distinctive accent color for the transition space, edge of the hallways or in front of the door to the units and having different color for each floor. But in most facilities except one or two, this consideration is ignored. Fourth, there is difference in color selection between elderly housing with low and high rental value. Only one facility, the most high priced one, has aggressive color arrangement, and the others show very little consideration of the elderly's needs.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1447-1460
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• 2021

Urbanization increases the amount of impervious surface and artificial heat emission, resulting in urban heat island (UHI) effect. Local climate zones (LCZ) are a classification scheme for urban areas considering urban land cover characteristics and the geometry and structure of buildings, which can be used for analyzing urban heat island effect in detail. This study aimed to examine the UHI effect by urban structure in Suwon and Daegu using the LCZ scheme. First, the LCZ maps were generated using Landsat 8 images and convolutional neural network (CNN) deep learning over the two cities. Then, Surface UHI (SUHI), which indicates the land surface temperature (LST) difference between urban and rural areas, was analyzed by LCZ class. The results showed that the overall accuracies of the CNN models for LCZ classification were relatively high 87.9% and 81.7% for Suwon and Daegu, respectively. In general, Daegu had higher LST for all LCZ classes than Suwon. For both cities, LST tended to increase with increasing building density with relatively low building height. For both cities, the intensity of SUHI was very high in summer regardless of LCZ classes and was also relatively high except for a few classes in spring and fall. In winter the SUHI intensity was low, resulting in negative values for many LCZ classes. This implies that UHI is very strong in summer, and some urban areas often are colder than rural areas in winter. The research findings demonstrated the applicability of the LCZ data for SUHI analysis and can provide a basis for establishing timely strategies to respond urban on-going climate change over urban areas.