• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.89-100
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• 2021

This study evaluated the degree of interaction between the people and the environment using perceived naturalness measure. The seventh-grade index of Hemeroby was divided into subclasses of land cover according to degrees of human influence. The grade was standardized for each indicator to evaluate the current state of urban parks in Seoul by applying probability density function and weight. User evaluation was conducted on six distinctive parks selected. In the results, three implications were found between spatial evaluation according to the perceived naturalness. First, park users evaluated highly for the spaces such as broad-leaved forest, coniferous forest and mixed forest evaluated highly in the Hemeroby grade index. Park users generally recognized that various types of trees in the area had high naturalness. The density of trees is one of the factors in perceived naturalness. Second, water spaces were highly evaluated for naturalness in the Hemeroby grade index. However, the perceived naturalness of water spaces such as inland wetlands, pond and reservoir evaluated in various ways depending on environmental conditions around the park. Third, perceived naturalness is easily evaluated through vertical landscape elements such as trees rather than horizontal landscapes such as grassland. The perceived naturalness is similar to the naturalness evaluation using land cover. However the study found the perceived naturalness for a specific space was different from the Hemeroby index. Perceived naturalness by the user includes the content that the individual sees, hears, and experiences. Park users are usually structuring naturalness through evaluating the value of urban green spaces based on personal perception. Therefore there is no absolute standard criterion for evaluating the naturalness of urban green spaces. A deeper study is needed that considers user bundles or user groups with conflicting interests on the perceived naturalness in urban parks. These studies will be essential data on the direction of naturalness urban park service should provide.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.202-211
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• 2011

The geometric characteristics of step-pool structures and how they are influenced by channel characteristics were investigated in a steep mountain stream in the Experimental Forests of Kangwon National University in Chuncheon, Gangwon-do. Average values of steps for the study reaches were as follows: step spacing, 4.69 m; step height, 0.47 m; step drop, 0.71 m; step-forming particle sizes, 0.68 m; number, 21steps/ 100 m; the ratio of step spacing to channel width, 0.5; and step steepness, 0.13. Relationships between spacing and height of steps and channel gradient showed a negative- and positive correlation, respectively, whereas all geometric variables of steps manifested poor correlation with channel width. Therefore, step steepness, expressed as the ratio of step height to step spacing, increased as channel gradient increased. The ratio of step steepness to channel gradient representing the criterion of maximum flow resistance was 1.2, indicating the channel bed's stable condition. In particular, the relationship between the ratio of step drop to step height and channel gradient showed a significant negative correlation, suggesting the influence of step-pool geometry in trapping sediment and providing an aquatic habitat. Positive correlations also exist between spacing and drop of steps and step particles. Our findings suggest that the dynamics of step-pool structures may strongly control physical and ecological environments in steep mountain streams, so understanding them is essential for stream management.

• The Journal of Korean Philosophical History
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• no.54
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• pp.153-184
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• 2017

During the Pre-Qin(秦) Dynasty era, there were the records that there had been many calendar systems, such as $g{\check{u}}-li{\grave{u}}-l{\grave{i}}$(古六曆 : six ancient calendar systems). Then, the fact that particularly $zh{\bar{o}}u-l{\grave{i}}$(周曆) and $xi{\grave{a}}-l{\grave{i}}$(夏曆) were mainly discussed among them resulted from a lot of discussions from the differences in the calendar system in "$Ch{\bar{u}}n-qi{\bar{u}}$(春秋)" known to have been written by Confucius from the calendar system in "$X{\acute{i}}ng-xi{\grave{a}}-zh{\bar{i}}-sh{\acute{i}}$(行夏之時 : implement the calendar of Ha dynasty.)" that Confucius mentioned himself to his disciple. $zh{\bar{o}}u-l{\grave{i}}$(周曆) with $d{\bar{o}}ngzh{\grave{i}}-yu{\grave{e}}$(冬至月 : the 11th month of the lunar calendar) as the first month of a year had the system of the lunar calendar, and $xi{\grave{a}}-l{\grave{i}}$(夏曆) called as the calendar of Ha(夏) dynasty had the system of $ji{\acute{e}}-q{\grave{i}}-l{\grave{i}}$(節氣曆 : a kind of the solar calendar that divides one year of 365 days into 24 solar terms) with $y{\acute{i}}n-yu{\grave{e}}$(寅月 :one month from the present Feb 5) as the first month of a year. These two calendars had definite differences in the first months of a year, names of seasons, and the lunar calendar and the solar calendar. The fundamental reason why Confucius recommended the performance of $xi{\grave{a}}-l{\grave{i}}$(夏曆) as a way to run the nation was not that it started from the philosophical view of the universe that among the 'three $zh{\bar{e}}ng$'(三正)' of $ti{\bar{a}}n-zh{\bar{e}}ng$(天正 : the first month of a year with the heaven as the standard), $d{\grave{i}}-zh{\bar{e}}ng$(地正 : the first month of a year with the earth as the standard) and $r{\acute{e}}n-zh{\bar{e}}ng$(人正 : the first month of a year with humans as the standard), but that he wanted to emphasize the importance of practical national economic policies to enhance agricultural productivity. It becomes the criterion that even though Confucius emphasized that politicians should not have moral flaws ideally, with regard to public policies, he wanted to stress politicians' duties based on the reality a lot.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.39-46
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• 2021

The quantitative measurement of interfacial adhesion energy (Gc) of multilayer thin films for Cu interconnects was investigated using a double cantilever beam (DCB) and 4-point bending (4-PB) test. In the case of a sample with Ta diffusion barrier applied, all Gc values measured by the DCB and 4-PB tests were higher than 5 J/㎡, which is the minimum criterion for Cu/low-k integration without delamination. However, in the case of the Ta/Cu sample, measured Gc value of the DCB test was lower than 5 J/㎡. All Gc values measured by the 4-PB test were higher than those of the DCB test. Measured Gc values increase with increasing phase angle, that is, 4-PB test higher than DCB test due to increasing plastic energy dissipation and roughness-related shielding effects, which matches well interfacial fracture mechanics theory. As a result of the 4-PB test, Ta/Cu and Cu/Ta interfaces measured Gc values were higher than 5 J/㎡, suggesting that Ta is considered to be applicable as a diffusion barrier and a capping layer for Cu interconnects. The 4-PB test method is recommended for quantitative adhesion energy measurement of the Cu interconnect interface because the thermal stress due to the difference in coefficient of thermal expansion and the delamination due to chemical mechanical polishing have a large effect of the mixing mode including shear stress.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.167-176
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• 2022

Adaptive optics (AO) systems compensate for atmospheric disturbance, especially phase distortion, by introducing counter-wavefront deformation calculated from real-time wavefront sensing or prediction. Because AO system implementations are time-consuming and costly, it is highly desirable to estimate the system's performance during the development of the AO system or its parts. Among several techniques, we mostly apply statistical analysis, computational simulation, and optical-bench tests. Statistical analysis estimates performance based on the sum of performance variances due to all design parameters, but ignores any correlation between them. Computational simulation models every part of an adaptive optics system, including atmospheric disturbance and a closed loop between wavefront sensor and deformable mirror, as close as possible to reality, but there are still some differences between simulation models and reality. The optical-bench test implements an almost identical AO system on an optical bench, to confirm the predictions of the previous methods. We are currently developing an AO system for a 1.6-m ground telescope using a deformable mirror that was recently developed in South Korea. This paper reports the results of the statistical analysis and computer simulation for the system's design and confirmation. For the analysis, we apply the Strehl ratio as the performance criterion, and the median seeing conditions at the Bohyun observatory in Korea. The statistical analysis predicts a Strehl ratio of 0.31. The simulation method similarly reports a slightly larger value of 0.32. During the study, the simulation method exhibits run-to-run variation due to the random nature of atmospheric disturbance, which converges when the simulation time is longer than 0.9 seconds, i.e., approximately 240 times the critical time constant of the applied atmospheric disturbance.

• Journal of agricultural medicine and community health
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• v.47 no.3
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• pp.181-188
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• 2022

Objectives: The prevalence of diabetes mellitus was approximately 16% in populations of over age 30 years, and deaths from diabetes mellitus became the sixth most prevalent cause of death by disease. To assess the relationship between HbA1c and heavy metal level in blood and urine, targeted residents were evaluated in a vast steel industrial complex. Methods: We selected 414 subjects for analysis after applying the following exclusion criterion: 18 persons with diabetes mellitus. They took part in a questionnaire survey and underwent blood and urinary assessments. HbA1c and lead (Pb) level were measured in blood and, cadmium (Cd), inorganic arsenic (iAs) and mercury (Hg) were evaluated in urine. Two subgroups were divided by HbA1c 6.5%. Each subgroup was divided by 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th and 90th percentile levels of biological exposure index of the heavy metals for logistic regression. Results: Odd ratios have a tendency to increase as they go from the 90th to the 10th percentile of cadmium. However, lead, arsenic and mercury did not have significant relationships with HbA1c. In correction of age, region, gender and smoking history, a higher distribution in the subgroup with cadmium above 0.8318 ㎍/g creatinine (30th percentile) was demonstrated in the subgroup with HbA1c levels above the 6.5%, with an odds ratio of 5.26 (95% C.I. ; 1.44~19.17). Conclusion: This study found a significant correlation between urinary levels of cadmium and HbA1c in correction of several factors. It is meaningful that this outcome may be used as a basis for a study to establish the acceptable limit of urinary cadmium in Korea.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.311-318
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• 2022

We conducted this study to derive the site index, which is a criterion for the planting of Robinia pseudoacacia, a honey plant, and to investigate the diameter distribution change by derived site index. We applied the Chapman-Richards equation model to estimate the site index of the Robinia pseudoacacia stand. The site index was distributed within the range of 16-22 when the base age was 30 years. The fitness index of the site index estimation model was low, but we judged that there was no problem in the application because the residual distribution of the equation had not shifted to one side. We used the Weibull diameter distribution function to determine the diameter distribution of the Robinia pseudoacacia stand by site index. We used the mean diameter and the dominant tree height as independent variables to present the diameter distribution, and our analysis procedure was to estimate and recover the parameters of the Weibull diameter distribution function. We used the mean diameter and the dominant tree height of the Robinia pseudoacacia stand to show distribution by diameter class, and the fitness index for dbh distribution estimation was about 80.5%. As a result of schematizing the diameter distribution by site indices as a 30-year-old, we found that the higher the site index, the more the curve of the diameter distribution moved to the right. This suggests that if the plantation were to be established in a high site index stand, considering the suitable trees on the site, the growth of Robinia pseudoacacia woul d become active, and not onl y the production of wood but al so the production of honey would increase. We therefore anticipate that the site index classification table and curve of this Robinia pseudoacacia stand will become the standard for decision making in the plantation and management of this tree.

• (The) Research of the performance art and culture
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• no.39
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• pp.701-748
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• 2019

Gwanak-yeongsanhoesang, called as Samhyeon-yeongsanhoesang or Pyojeongmanbangjigok, is played by the musical instrumental organization, Samhyeonyukgak or by a large scale wind ensemble added Sogeum and Ajaeng. This study aims to analyze the structure and form of Piri melody which plays major melody of Sangnyeongsan in Gwanak-yeongsanhoesang, and to examine the relationship between Piri melody and Daegeum yeoneum grasping the structure and function of yeoneum. In Sangnyeongsan of Gwanak-yeongsanhoesang, the criterion for grouping the phrases of Piri melody is yeoneum. Especially, Daegeum yeoneum carries out the function of finishing the phrase of Piri playing the major melody by ornamenting or extending it, and presenting the motives or motive elements of the next phrase while Piri rests. The types of a, b, g, and i in the various shapes of the minimum melodic fragment of Piri are important motive elements that constitute a phrase of Piri melody. Especially, main motive a-type (仲→無) contrasts with b type (林→潢) which forms a strong tension by transposing 2 degrees upward. In addition, a-type gradually descends towards the end of music by changing to g-type (仲→林) or to i-type (太→林) which is 3 degrees below, which is related to the gradual descent cadence of Korean traditional music. A phrase of Piri melody of Sangnyeongsan in Gwanak-yeongsanhoesang consists of a combination of the types a, b, g, i, and cadence (x-type), and each phrase is structured in the repeating tension-relaxation. Looking at the structure of Piri phrases by similar types, each phrase has a logical variation structure through the methods such as omission and addition of notes, and crossing of melodies. The shape of the minimum melodic fragment of Daegeum yeoneum can be divided into a back-yeoneum of a~b types and a front-yeoneum of x1~x3. The x-types ornament Jungnyeo (仲), the cadence tone of Piri melody or are simply used as the extending back-yeoneum, and types a and b have the function of a front-yeoneum that prepares the beginning of the next phrase of Piri melody. The combination types of the minimum melodic fragment of Daegeum yeoneum appear mostly as the shape of back-yeoneum + front-yeoneum. In addition, the front-yeoneum of the type a and b appears independently without back-yeoneum, and the x3 type has a shape of the back-yeoneum without the front-yeoneum. Looking at the structure of Daegeum yeoneum by similar types, it can be seen that Daegeum yeoneum is also composed of a variation structure of omission and addition of notes like Piri melody.

• Communications of Mathematical Education
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• v.37 no.2
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• pp.233-256
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• 2023

This study conducted foundational research to derive ways to use ChatGPT in mathematics education by analyzing ChatGPT's responses to questions from the National Assessment of Educational Achievement (NAEA) and the College Scholastic Ability Test (CSAT). ChatGPT, a generative artificial intelligence model, has gained attention in various fields, and there is a growing demand for its use in education as the number of users rapidly increases. To the best of our knowledge, there are very few reported cases of educational studies utilizing ChatGPT. In this study, we analyzed ChatGPT 3.5 responses to questions from the three-year National Assessment of Educational Achievement and the College Scholastic Ability Test, categorizing them based on the percentage of correct answers, the accuracy of the solution process, and types of errors. The correct answer rates for ChatGPT in the National Assessment of Educational Achievement and the College Scholastic Ability Test questions were 37.1% and 15.97%, respectively. The accuracy of ChatGPT's solution process was calculated as 3.44 for the National Assessment of Educational Achievement and 2.49 for the College Scholastic Ability Test. Errors in solving math problems with ChatGPT were classified into procedural and functional errors. Procedural errors referred to mistakes in connecting expressions to the next step or in calculations, while functional errors were related to how ChatGPT recognized, judged, and outputted text. This analysis suggests that relying solely on the percentage of correct answers should not be the criterion for assessing ChatGPT's mathematical performance, but rather a combination of the accuracy of the solution process and types of errors should be considered.

• Analytical Science and Technology
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• v.19 no.3
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• pp.263-271
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• 2006

The levels of total PCBs, Co-PCBs and PCDD/Fs in the transformer insulation oil samples obtained using GC/ECD and HRGC/HRMS were ranged from N.D. to 77.3 ppm, from 0.0863 to 2.49 ppm and from N.D. to 0.00241 ppm, respectively. In terms of WHO-TEQ values, Co-PCBs and PCDD/Fs were ranged from 23.3 to 600 pgTEQ/g and from N.D. to 128 pgTEQ/g, respectively (${\Sigma}Co$-PCBs+PCDD/Fs concentration was calculated 24.4~728 pgTEQ/g). Although, the contribution of PCDD/Fs was below 12% in total TEQ concentration, it is suggested contamination of PCDD/Fs in transformer insulation oils. Among 10 samples, 4 samples showed higher concentration than 2 ppm (specific waste criterion of Korea) and Aroclor 1242, 1248, 1254 and 1260 was detected in samples as a single or mixture of Aroclor. It was shown reliable relationship between concentration of Co-PCBs and those of PCDD/Fs (p<0.003), however, was not shown between production year of transformer and concentration of PCBs. The distribution pattern of Co-PCB congeners showed that the ratios of mono-ortho substituted congeners were higher than non-ortho substituted congeners. Among that, PCB-118 congener was predominant. In addition, the OCDD congener was predominated in PCDD/Fs congeners as above 53%. Moreover, the congener pattern of Co-PCBs was similar to that of Aroclor as well as ambient air, which suggested that PCBs volatilization from transformer insulation oil affected the pattern of Co-PCBs in ambient air.