• Journal of Intelligence and Information Systems
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• v.28 no.3
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• pp.105-117
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• 2022

This study analyzes the effects between stock returns and interest rate spread, difference between long-term and short-term interest rate through the polynomial linear regression analysis. The existing research concentrated on the business forecast through the interest rate spread focusing on the US market. The previous studies verified the interest rate spread based on the leading indicators of business forecast by moderating the period of long-term/short-term interest rates and analyzing the degree of leading. After the 7th reform of composite indices of business indicators in Korea of 2006, the interest rate spread was included in the items of composing the business leading indicators, which is utilized till today. Nevertheless, there are a few research on stock returns of each industry and interest rate spread in domestic stock market. Therefore, this study analyzed the stock returns of each industry and interest rate spread targeting Korean stock market. This study selected the long-term/short-term interest rates with high causality through the regression analysis, and then understood the correlations with each leading period and industry. To overcome the limitation of the simple linear regression analysis, polynomial linear regression analysis is used, which raised explanatory power. As a result, the high causality was verified when using differences between returns of corporate bond(AA-) without guarantee for three years by leading six months and call rate returns as interest rate spread. In addition, analyzing the stock returns of each industry, the relation between the relevant interest rate spread and returns of the automobile industry was the closest. This study is significant in the aspect of verifying the causality of interest rate spread, business forecast, and stock returns in Korea. Even though it could be limited to forecast the stock price by using only the interest rate spread, it would be working as a strong factor when it is properly utilized with other various factors.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.939-951
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• 2022

The most important factor in designing autonomous driving systems is to recognize the exact location of the vehicle within the surrounding environment. To date, various sensors and navigation systems have been used for autonomous driving systems; however, all have limitations. Therefore, the need for high-definition (HD) maps that provide high-precision infrastructure information for safe and convenient autonomous driving is increasing. HD maps are drawn using three-dimensional point cloud data acquired through a mobile mapping system (MMS). However, this process requires manual work due to the large numbers of points and drawing layers, increasing the cost and effort associated with HD mapping. The objective of this study was to improve the efficiency of HD mapping by segmenting semantic information in an MMS point cloud into six classes: roads, curbs, sidewalks, medians, lanes, and other elements. Segmentation was performed using various machine learning techniques including random forest (RF), support vector machine (SVM), k-nearest neighbor (KNN), and gradient-boosting machine (GBM), and 11 variables including geometry, color, intensity, and other road design features. MMS point cloud data for a 130-m section of a five-lane road near Minam Station in Busan, were used to evaluate the segmentation models; the average F1 scores of the models were 95.43% for RF, 92.1% for SVM, 91.05% for GBM, and 82.63% for KNN. The RF model showed the best segmentation performance, with F1 scores of 99.3%, 95.5%, 94.5%, 93.5%, and 90.1% for roads, sidewalks, curbs, medians, and lanes, respectively. The variable importance results of the RF model showed high mean decrease accuracy and mean decrease gini for XY dist. and Z dist. variables related to road design, respectively. Thus, variables related to road design contributed significantly to the segmentation of semantic information. The results of this study demonstrate the applicability of segmentation of MMS point cloud data based on machine learning, and will help to reduce the cost and effort associated with HD mapping.

• Korean small business review
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• v.42 no.3
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• pp.101-121
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• 2020

Marking the 40th anniversary of the founding of The Korean Association of Small Business Studies, this paper was carried out to shed light on the historical trend of 40 years of small and medium business research through the papers published in the Asia Pacific Journal of Small Business and to consider the direction of future small and medium business research. In particular, we will focus on small and medium venture business policies and strategic management aspects of small and medium venture businesses to analyze the contents of published papers related to the subject and contribute to finding implications and future research directions. In order to analyze the research trends of small and medium venture business policies and strategic management sectors of small and medium venture companies covered in the Asia Pacific Journal of Small Business from 1979 to 2019, the analysis was divided by time and item based on research subjects, research methods, researchers, etc., and the primary analysis results are as follows: First, out of a total of 1,056 research papers, research papers on small and medium venture enterprise policy and strategic management showed a ratio of about 14% and 11% of the total research. Second, in terms of research subjects, the proportion of policy research on funds and start-ups and ventures was high in the field of small and medium venture enterprise policy, and the research on internationalization strategy was carried out the most in the area of strategic management. Third, qualitative research was more prominent until the 1980s, but the proportion of quantitative research began to increase after the 1990s, and since then, quantitative research has been carried out more than qualitative research. Fourth, over the past 40 years, Hanyang University, Kyungpook National University, Konkuk University, etc. were the institutions that presented research papers most actively in the areas of small and medium venture business policy and strategic management, and the research institute's participation was somewhat insufficient. The main implications of this study for the continuous development of the Asia Pacific Journal of Small Business are as follows. First, it is necessary to enhance the link between research on policy research and strategic management of small and medium venture companies in terms of research subject matter. Second, more diversity should be pursued in terms of research methods. Third, it is necessary to increase the participation rate of public and private research institutes related to small and medium venture enterprises in academic societies.

• Journal of The Korean Association For Science Education
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• v.41 no.6
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• pp.483-499
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• 2021

The curriculum localization policy is closely related to the decentralization and autonomy policy, which is a direction of the 2022 revised curriculum. In particular, considering the continuously expanding and changing environment and contents in science education, the localization of the science curriculum has the advantage of advancing to expertise through diversity. In this paper, through experts' perception of the science curriculum localization policy, the implications of the curriculum revision were confirmed, focusing on 'MPOE(Metropolitan and Provincial Offices of Education) curriculum arrangement and implementation guidelines(hereinafter referred to as 'guidelines')' and the achievement standards revision of science curriculum. In conclusion, study participants considered that the possibility of expanding the localization of the curriculum was high due to the unique characteristics of science practices. And they recognized the level of localization at the 'district office of education or village'-level between MPOE-level and school-level. When localization reaches the school-level in the future, it was considered necessary to discuss linkage with teacher policies such as teacher's competency, noting that the level of teachers could become the level of localization. In addition, there was a common perception that in order for the science 'guidelines' to be localized, 17 MPOE must be given the authority to autonomously organize some achievement standards in parallel. It was considered that 'restructuring or slimming of achievement standards' should precede localization of achievement standards in connection with this. On the other hand, it was predicted that the curriculum localization policy would enhance the aspect of diversification and autonomy of the science curriculum, and the establishment of achievement standards was directly related to evaluation, so it recognized the need to refine policies such as new description for evaluation clause in future science 'guidelines'. Finally, considering science and characteristics, it was mentioned that it is necessary to specify regional intensive science education policies in the 'guidelines' themselves beyond the localization of teaching materials.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.181-188
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• 2022

This study was conducted to investigate the effects of the metabolic energy levels of Korean native chicken breeder diets on laying performance, egg quality, fertility and hatchability. On the basis of dietary metabolic energy values (2,800, 2,700, and 2,650 kcal/kg), 168 twenty-week-old 'Woorimatdag' breeders (maternal line) were divided into three treatment groups (four replications per treatment with each replicate containing 14 birds) and reared until 32 weeks of age. We found that the body weight of hens increased with age, although there were no significant differences among treatments with respect to body weight or egg weight. Egg production ratio at 20-24 and 24-28 weeks of age tended to be low in birds fed the 2,700 and 2,650 kcal/kg diets, although the differences among treatments were none significant. Feed intakes was significantly decreased as the metabolic energy level reduced (P<0.05). There were no significant differences among treatments with respect to feed conversion ratio or the strength and thickness of eggshell. Similarly, we detected no significant differences among the three metabolic energy levels with regards to fertility, hatchability, or chick weight. In conclusion, our findings indicate that during the initial phase of laying, the metabolic energy level of 'Woorimatdag' breeder diets could be lowered to 2,700 kcal/kg without significantly influencing the laying performance of breeders or egg quality, fertility and hatchability, and chick weight.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.300-310
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• 2022

The objective of this experiment was to investigate the effect of drip irrigation volume on tomatoes (Solanum lycopersicum L.) grown in a greenhouse using perlite medium. Plants were treated by three different irrigation treatment I₀, I₂₅, and I₅₀ (where irrigation volume of I₂₅ and I₅₀ was 25% and 50% higher than I₀, having limited or no leaching). Growth characteristics of plants, yield and water use efficiency were measured. The result showed that plant height, leaf length and leaf width were lowest in the I₀ treated plants. However, these parameters were not statistically significant differences between the plants that were grown in the I₂₅ and I₅₀ treatment. Soluble solids content, acidity and dry matter of 111th, 132nd, and 143rd days harvested tomato were higher in the plants irrigated with lowest volume (I₀) than the higher volume (I₂₅ or I₅₀). In addition, water content was lower in the 111th and 132nd days of harvested tomatoes from the I₀ treatment. The number of big-size tomatoes (>180 g) was significantly higher in the I₂₅ irrigated plants. There was no significant difference in the total number of harvested fruits among the treatments. The average fruit weight and total yield of harvested tomatoes were lowest in the I₀ treated plants. The water consumption of tomato was not significantly different amongst the treatments but water use efficiency was lowest in the I₀ treatment. Principal component analysis revealed that total soluble solid and acidity of tomato showed a positive correlation between each other. These results suggest that I₂₅ was the optimum irrigation treatment for tomato based on its measured growth characteristics, yield and water use efficiency.

• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.220-256
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• 2022

The most important thing for conserving plant diversity in an area is to make an overall inventory of the plant species inhabiting the area. In particular, limestone areas are known for their high plant diversity and distribution of specific plants. Despite that, only a few have been designated as protected areas. This study investigated the vascular plants distributed in Goyangsan Mtn. and Munraesan Mtn., located in limestone areas of the central part of the Korean Peninsula. A field survey was conducted eight times from April to October 2021. As a result, we identified a total of 654 taxa comprising 113 families, 357 genera, 592 species, 15 subspecies, 44 varieties, and 3 formulas. They included four endangered wild plant species: Astilboides tabularis, Eleutherococcus senticosus, Cypripedium macranthos, and Epilobium hirsutum. Endemic plants in Korea were identified as 32 taxa. Floristic target plants were identified as 168 taxa, specifically 5 taxa of grade V, 41 taxa of grade IV, and 36 taxa of grade III. The red data plants included 2 taxa as "Endangered (EN)", 7 taxa as "Vulnerable (VU)", and 7 taxa as "Near threatened (NT)". A total of 41 taxa of naturalized plants were identified, and 4 of them were invasive alien plants. The surveyed vicinity of Goyangsan Mtn. and Munraesan Mtn. showed high plant diversity and contained core habitats for distribution of an endangered wild plant, Astilboides tabularis,in the limestone area. Moreover, both mountains contained a small population of Cotoneaster integerrimus. These findings confirm that the area has conservation values. Therefore, we propose to identify areas with high plant diversity and designate them as special protected areas.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1735-1752
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• 2021

In this study, the Bodhi tree powder is used as an additive to Seolgi rice cake and the research is made how useful the additives are to the Seolgi rice cake. This research would be a good way to develop and distribute the Seolgi rice cake which is added with the powder of Bodhi tree. The results of the study are as follows. 1. The water contents of Bodhi tree was 81.64% with 1.75% of crude protein, 0.81% of crude fat, and 0.56% of crude ash. It was found out that the Bodhi tree has higher contents of polypherol and has the efficacy of anti-oxidation property and has the value as the food stuff. 2. When the Seolgi rice cake is made with the addition of Bodhi tree powder, the value of a and b, sugar, hardness, elasticity, texture and viscosity have risen while the contents of water, L value, pH, stickiness and cohesiveness were lowered. The property test showed that the addition of Bodhi tree to Seolgi rick cake would make all testing items "strong" and the addition of 4% of Bodhi tree in the manufacturing of Seolgi rice cake was most preferred. 3. As for the storage of Seolgi rice cake is concerned, as the period of storage goes by, the value a and b, hardness, elasticity and texture and viscosity have increased while the water contents, L value, stickiness and cohesiveness have reduced. As the period of storage gets longer, the total cell number has increased. But as the more volume of Bodhi tree is added to the rice cake, the total cell number has reduced, thus lengthening the storage period. The rest shows that in producing the Seolgi rice cake, the 4% of addition of Bodhi rice cake is deemed to be the best. It was confirmed that the proper volume of Bodhi powder is proper for the Seolgi rice cake and is also good for decorative and quality characteristics for the rice cake.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.623-634
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• 2022

Due to river maintenance projects such as the creation of hydrophilic areas around rivers and the Four Rivers Project, the flow characteristics of rivers are continuously changing, and the risk of water quality accidents due to the inflow of various pollutants is increasing. In the event of a water quality accident, it is necessary to minimize the effect on the downstream side by predicting the concentration and arrival time of pollutants in consideration of the flow characteristics of the river. In order to track the behavior of these pollutants, it is necessary to calculate the diffusion coefficient and dispersion coefficient for each section of the river. Among them, the dispersion coefficient is used to analyze the diffusion range of soluble pollutants. Existing experimental research cases for tracking the behavior of pollutants require a lot of manpower and cost, and it is difficult to obtain spatially high-resolution data due to limited equipment operation. Recently, research on tracking contaminants using RGB drones has been conducted, but RGB images also have a limitation in that spectral information is limitedly collected. In this study, to supplement the limitations of existing studies, a hyperspectral sensor was mounted on a remote sensing platform using a drone to collect temporally and spatially higher-resolution data than conventional contact measurement. Using the collected spatio-temporal hyperspectral images, the tracer concentration was calculated and the transverse dispersion coefficient was derived. It is expected that by overcoming the limitations of the drone platform through future research and upgrading the dispersion coefficient calculation technology, it will be possible to detect various pollutants leaking into the water system, and to detect changes in various water quality items and river factors.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.253-261
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• 2022

The purpose of this study is to investigate the relationship between transformative leadership, team cohesion, and team performance of Chinese university taekwondo leaders. Specifically, it is to investigate the effect of transformative leadership on team cohesion and team performance and to verify the mediating effect of team cohesion in the relationship between transformative leadership and team performance. In order to achieve the research purpose, a total of 350 people were sampled after setting taekwondo leaders at Chinese universities as a population. The measurement tool used in this study was a questionnaire consisting of 5 items on demographic characteristics, a total of 19 questions on transformational leadership, 10 questions on team cohesion, and 4 questions on team performance. The validity of the questionnaire was verified through exploratory factor analysis, and the reliability was verified through reliability analysis. The reliability Cronbach's α of the questionnaire was found to be α=0.755-0.799 for transformative leadership, α=0.848, and α=0.740 for team performance. As the data processing method, exploratory factor analysis and reliability analysis, one-way analysis (one-way ANOVA), and multiple regression analysis were used using SPSS WIN. The conclusions derived through the above research methods and procedures are as follows. First, the transformative leadership of Taekwondo leaders at Chinese universities influenced team cohesion. Second, the transformative leadership of Taekwondo leaders at Chinese universities influenced team performance. Third, the team cohesiveness of Taekwondo leaders at Chinese universities influenced team performance. Fourth, the transformative leadership of Taekwondo leaders at Chinese universities not only directly affects team performance, but also indirectly affects team cohesion. Therefore, it is believed that Chinese Taekwondo players will help improve their performance by affecting team cohesion and team performance for the best games through the leader's variable leadership.