• Communications of Mathematical Education
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• v.37 no.1
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• pp.65-84
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• 2023

The method of Lagrange multipliers, one of the most fundamental algorithms for solving equality constrained optimization problems, has been widely used in basic mathematics for artificial intelligence (AI), linear algebra, optimization theory, and control theory. This method is an important tool that connects calculus and linear algebra. It is actively used in artificial intelligence algorithms including principal component analysis (PCA). Therefore, it is desired that instructors motivate students who first encounter this method in college calculus. In this paper, we provide an integrated perspective for instructors to teach the method of Lagrange multipliers effectively. First, we provide visualization materials and Python-based code, helping to understand the principle of this method. Second, we give a full explanation on the relation between Lagrange multiplier and eigenvalues of a matrix. Third, we give the proof of the first-order optimality condition, which is a fundamental of the method of Lagrange multipliers, and briefly introduce the generalized version of it in optimization. Finally, we give an example of PCA analysis on a real data. These materials can be utilized in class for teaching of the method of Lagrange multipliers.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.13-23
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• 2022

In this paper, we propose a detailed component image classification algorithm by fashion item for unstructured data retrieval in the fashion field. Due to the COVID-19 environment, AI-based online shopping malls are increasing recently. However, there is a limit to accurate unstructured data search with existing keyword search and personalized style recommendations based on user surfing behavior. In this study, pre-processing using Mask R-CNN was conducted using images crawled from online shopping sites and then classified components for each fashion item through CNN. We obtain the accuaracy for collar of the shirt's as 93.28%, the pattern of the shirt as 98.10%, the 3 classese fit of the jeans as 91.73%, And, we further obtained one for the 4 classes fit of jeans as 81.59% and the color of the jeans as 93.91%. At the results for the decorated items, we also obtained the accuract of the washing of the jeans as 91.20% and the demage of jeans accuaracy as 92.96%.

• Journal of Platform Technology
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• v.10 no.3
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• pp.60-68
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• 2022

As AI-technology develops, interest in the safety of autonomous driving is increasing. Recently, autonomous vehicles have been increasing, but efforts to solve side effects have been sluggish. In particular, night autonomous vehicles have more problems. This is because the probability of accidents is higher in the night driving environment than in the day environment. There are more factors to consider for self-driving at night. Among these factors, reflection of light or reflected light of lighting may be a fundamental cause of night accidents. Therefore, this study proposes method to reduce accidents and improve safety by reducing reflected light generated by the headlights of opposite vehicles or various surrounding light that appear as an important problem in night autonomous vehicles. Therefore, first, in an image obtained by a sensor of a night autonomous vehicle, illumination reflected light is extracted using reflected light characteristic information, and a color of each pixel using a reflection coefficient is found to reduce a special area generated by geometric characteristics. In addition, we find a new area using only the brightness component of the specular area, define it as Illuminated Reflection Light (IRL), and finally present a method to reduce it. Although the illumination reflection light could not be completely reduce, generally satisfactory results could be obtained. Therefore, it is believed that the proposed study can reduce casualties by solving the problems of night autonomous driving and improving safety.

• Journal of The Korean Association of Information Education
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• v.26 no.6
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• pp.567-577
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• 2022

Interest in AI and SW education is growing as digital literacy is emphasized in the revised elementary school curriculum for 2022. There are numerous restrictions on how pupils can enhance their digital literacy because there are only 34 class hours available for information education in elementary schools. Therefore, other subjects and information education must be blended in order to ensure class hours for AI and SW instruction. In this study, we investigated the impact of S-PUMA reading instruction on the literary imagination and computational thinking of elementary school pupils. To conduct this study, two classes of sixth graders in an elementary school were chosen and split into an experimental group and a control group. Over the course of five sessions, only the experimental group received reading instruction using the S-PUMA teaching approach. It was discovered that reading instruction with the S-PUMA teaching methodology enhanced literary imagination and computational thinking. Further study is required to identify whether the improvement in creative imagination, a component of literary imagination, is a result of the S-PUMA teaching approach or a natural result of the subject matter of the lesson.

• Journal of the Korean Dietetic Association
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• v.4 no.1
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• pp.20-29
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• 1998

The purpose of this study was to investigate the effect of food habits on blood components level(blood glucose, uric acid, hemoglobin, some lipids levels) and health condition in Taejon. The study was conducted with 250 subjects (male 130, female120) who visited in a general hospital from May to June in 1997. Questionaires were used for food habits. The data were analyzed by using $x^2$-test, t-test, ANOVA and multiple range test. Results were summerized s follow : mean of Broca Index were 110.0 $\pm$13.7% in male, 110.6$\pm$16.6% in female. Mean values of systolic blood pressure and diastolic blood pressure were 130.9$\pm$17.6mmHg, 76.2$\pm$12.6mmHg, respectively. The systolic blood pressure was significantly higher in man than woman, Mean serum total cholesterol, LDL-cholesterol, and HDL-cholesterol and triglyceride levels were 202.8$\pm$40.2, 121.1$\pm$35.5, 50.3$\pm$12.9, 157.1$\pm$112.6mg/dl, respectively. Triglyceride level was significantly higher in man than woman. But HDL-cholesterol was significantly lower in man than woman. And also, the value of LPH and AI were higher in man. So Man has more risk of atherogenesis than woman. Mean values of blood sugar, uric acid and hemoglobin was 102.7$\pm$1.36mg/dl and 14.1$\pm$1.56g/dl were higher in man than woman except blood sugar. Food habit of woman were better than it of man. The levels of education and income did not affect to food habit score. The most problem of habits were intake of salty food and lack of exercise. The intake of nutrients were higher as food habit score was higher. Intakes of energy, Ca, vitamin A and vitamin $B^1$ were lower than RDA's of nutrients in bad food habit group. This result did not show that blood components level and health condition were significantly different by food habits. But Broca Index and triglyceride levels were higher in bad food habit group than other groups, but not statistically significant. By this result, it is more needed food habit education to man and young people. The education of food habits will include the real methods of weight control, low intake of salt and exercise to bad food habit group.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.1-20
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• 1986

Physical, chemical and biological surveys on Nakdong River estuary were made from October, 1985 to September, 1986. 1. For all the seasons except summer, the sea surface temperature in northwest area of the line which linked from Seo Island to Jisim Island was I-2$^{\circ}$C lower than in southeast area, but in summer the sea surface temperature in northwest area was I-2$^{\circ}$C higher than in southeast area. On the contrary, bottom temperature of coastal area was 1$^{\circ}$C higher than that of oceanic area except winter. 2. Surface salinity in summer and fall has minimum value of 1. 9%0 and maximum value of 32.9%0. This large variation was caused by the runoff of the Nakdong River. Effect of less saline Nakdong River water in northwest area of the line which linked from Seo Island to Jisim Island was greater than in southeast area. A strong current rip always formed near this line. 3. The yellowish-green colored zone was observed in the Nakdong River estuary throughout the year by influence of river discharge. The characteristics of the water quality in the zone have shown that the water color was grade 7 by the Forel water-color meter, transparency was less than 4 m, and concentration of suspended solids was more than 5 mg/1. This water body was in the state of eutrophication in terms of chlorophyll-a and inorganic nitrogen concentration during summer season. 4. During the study period, total 276 taxa were identified. Most of them were diatoms and dinoflagellates which consisted of 97.5%. The component ratio of the above two groups was 84.4% and 13.1 % respectively. Diatoms were plentiful in December and dinoflagellates in July. Dominant species were Nitzschia seriata in October, Thalassiosira rotula in December, Skeletoncma costatum in April, and Nitzschia longissima in July. 5. A total of 47 zooplankton taxa was identified from the samples collected. Copepods were numerically the most important components of zooplankton communities in the study area. The domir:ant copepod species were Paracalanus parvus, Acartia clausi and Temora turbinata. Noctiluca scintillans was the next important component. The other zooplankton with minor abundance were Cladocera. Sagitta spp., Cnidaria, Mysidacea, Lucifer spp. and Amphipoda. 6. During the study period, fishes from 47 families and 87 species were sampled in th~ study area. The four most abundant fish species were Rep~mucen//'s valencicnnei, Leiognathus n~cha!is, Amblychaeturicllthys hexanema and Sardirel/a zun:zsi. The fish species of the secondary importance in abundance were Cynoglossus joyneri, Sillago sihama, Engra~lis japonicus, Encdrias nebulos'l, Acanthogobius flavimanus, Trichiurus lepturus, LiParis tanai/ai, Cynagloss//'s interruptus, Aj)ogon line:z!us, Thrissz la 1l.'1la!ensis, and Limanda yokohamac.

• Journal of Families and Better Life
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• v.24 no.5 s.83
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• pp.69-87
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• 2006

This article attempts to explore how the women retirees under study were able to continue work until retirement. This study used life histories, especially focusing on daily working lives, and uncovered a number of key issues through in-depth interviews. The main results are as follows: Firstly, the women retirees examined here had been raised as highly educated people, and their strong educational background was a base component for them to have relatively secure careers. Their parents had also supported practically the women retirees during their working lives. In addition, the women retirees had to can out the roles of 'provider' for their original families, procreation families or in-law families, even though they were not given the recognized roles of provider. Secondly, the women retirees had a private infra system to support them with housework and child care. In addition, because they were financially able to employ housemaids, the women retirees did not experience conflicts with their husbands, who took on a neo-traditional sex role. Finally, thanks to relatively good working conditions such as having vacations and being able to come to and leave the office on time, the women retirees were able to continue work until retirement no mean feat in a society which openly practiced gender discrimination.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.252-256
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• 1999

Effects of gamma irradiation on lipid components, antioxidative enzyme activities and ${\alpha}-tocopherol$ in beef (M. Semitendinosus and Longissimus dorsi) were investigated. The lipid components (total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride and phospholipid) and the antioxidative enzyme activities (glutathione sulfur transferase, catalase and total superoxide dismutase) were not significantly changed by gamma irradiation up to 10 kGy (p>0.05). However, the contents of ${\alpha}-tocopherol$ in Longissimus dorsi significantly decreased with irradiation dose (P<0.05).

• The Journal of Advanced Prosthodontics
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• v.12 no.6
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• pp.369-375
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• 2020

PURPOSE. This study evaluated the availability of multi-directionally forged (MDF) titanium (Ti) as a component of removable partial dentures (RPDs). MDF-Ti remarkably improved the mechanical properties of RPDs due to its ultrafine-grained structure. MATERIALS AND METHODS. The wear resistance, plaque adhesion, and machinability of MDF-Ti were tested. As controls, commercially pure (CP) titanium was used for wear, plaque adhesion, and machinability tests. For wear resistance, the volume losses of the titanium teeth before and after wear tests were evaluated. Plaque adhesion was evaluated by the assay of Streptococcus mutans. In the machinability test, samples were cut and ground by a steel fissure bur and carborundum (SiC) point. An unpaired t-test was employed for the analysis of the significant differences between MDF-Ti and the control in the results for each test. RESULTS. Wear resistance and plaque adherence of MDF-Ti similar to those of CP-Ti (P>.05) were indicated. MDF-Ti exhibited significantly larger volume loss than CP-Ti in all conditions except 100/30,000 g/rpm in machinability tests (P<.05). CONCLUSION. Although the wear resistance and plaque adherence of MDF-Ti were comparable to those of controls, MDF-Ti showed better machinability than did CP-Ti. MDF-Ti could be used as a framework material for RPDs.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.145-159
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• 2020

Because of the recent development of information and communication technology, companies are exposed to various media such as blogs, social media, and YouTube. In particular, exposed news affects the company's reputation. So, while positive news can improve corporate value, negative news can lead to financial losses for the company. In this study, we redefine corporate reputation as social responsibility, vision and leadership, financial performance, products and services through existing literature, and conducted an AHP survey with a total of four components to calculate the weight of each factor. As a result of the calculation, the proportion of financial performance was the highest at 0.41, and products and services, vision and leadership, and social responsibility were the lowest. In addition, in order to measure the reputation of a company, it is classified as a component that defines online news using the LDA technique. In addition, through sentiment analysis, an index for each corporate reputation factor was derived, and the reputation index was calculated by combining it with the AHP analysis result, and Spearman ranking correlation analysis was performed to secure the validity of the research results. Therefore, the significance of this study is that the definition and importance of the constituent factors can contribute to the future planning and development direction of the company, and also contribute to the derivation of the corporate reputation index. This study is significant in that a new analysis methodology that applied AHP analysis results to sentiment analysis was suggested.