• East Asian mathematical journal
• /
• v.28 no.4
• /
• pp.383-401
• /
• 2012

The purpose of mathematics education includes two important areas; cognitive area that emphasizes mathematical knowledge and understanding and affective area that stresses mathematical interest and attitude. The purpose of mathematics education is not only in acquiring the contents and knowledge but also rousing up interest and attention toward mathematics. Therefore, effort to accomplish this affective purpose has to be made. Introducing history of mathematics to teaching can be a important method for the students to arouse interest and attention toward mathematics. History of mathematics can help the students who are familiar to only manipulation of the symbols to develop a new way of thinking and mathematical thoughts arousing reflective thinking. According to the survey, although the effect of using mathematics history has been recognized, the mathematics history has neither been developed as teaching materials nor reflected in the courses of study. The purpose of this research is to develop the reading materials into suit for the mathematics curriculum to extract contents of the mathematics valuable in using in elementary mathematics teaching, and to investigate the effect of reading materials using the history of mathematics on learning attitude in elementary school. The way of developing materials in this study is as follows. First, to select the interesting and instructive subject for the elementary students such as the story and life of a mathematician, developmental stages of mathematical theory and calculation currently used and finding the patterns of the rules that requires mathematical thoughts. Second, to classify the selected items according to mathematics curriculum. Third, to reorganize the classified items of the appropriate grade with the reading materials of dialogue pattern in order to draw attention and interest from the students I developed 18 kinds materials in accordance with the above procedure and applied 5 materials among them to one class in 4th grade. Analysing the student's responses, First, using history of mathematics helps the students to arouse interest and confidence on mathematical learning attitude. And the students became better attitude of studying by oneself and attention on class. Second, as know by opinions after lesson, most students have a chance refresh one's thinking of mathematics, want to know the other content of history of mathematics and responded to study hard in mathematics. As a result, the reading materials on the basis of the history of mathematics motivates students for mathematics and helps them become confident in mathematics. If the materials are complemented properly, they will be useful and effective for students and teachers.

• Korean Journal of Environmental Biology
• /
• v.23 no.1
• /
• pp.47-51
• /
• 2005

Three-weeks old Commelina communis was transferred to Hoagland solution (Control, 100 μM Cd/sup 2+/, 100 μM Cd/sup 2+/ + 100 μM ABA, 100 μM Cd/sup 2+/+50 mM KCl) and grown for a week in the solution and then a number of physiological activities were investigated. In cases of Cd/sup 2+/ and Cd/sup 2+/ + ABA treatments, the growth of the plants was inhibited to 71 % and 81 %, respectively, when compared with the control, but there were no significant difference of plant growth between Cd/sup 2+/ and Cd/sup 2+/ + KCl- treated plants. In the treatments of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCl total chlorophyll contents were reduced to 32%, 41% and 29%, respectively. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to 14∼20% and about 23%, respectively, according to the light intensity by Cd/sup 2+/ and Cd/sup 2+/+ABA-treated plants. Water stresses were increased by the treatment of Cd/sup 2+/, Cd/sup 2+/ + ABA and Cd/sup 2+/ + KCI. In Cd/sup 2+/ accumulation experiments Cd/sup 2+/ transport into the plant by ABA was not affected, but the accumulation of Cd/sup 2+/ into the roots was elevated to 13% when compared with the control. Cd/sup 2+/ transport into the root was markedly inhibited to 60% by KCl. Therefore, it could be concluded that ABA did not reduce the toxicities of Cd/sup 2+/, but enhanced Cd/sup 2+/ - induced toxicities and KCl showed no effect on Cd/sup 2+/ - induced toxicities.

• Journal of the Korean Institute of Gas
• /
• v.24 no.4
• /
• pp.84-92
• /
• 2020

Most facilities in chemical plants operate in environments that are outside the range of temperature and pressure that can be encountered on a daily basis, and are vulnerable to aging due to these stresses and environmental conditions. The facilities exposed to these conditions are not only likely to fail due to cumulative damage, but also lead to accidents if maintenance and replacement are not performed.Recommendation guidelines called risk-based inspection are widely used around the world-wide. However, limits exist for facilities that have already elapsed for a certain. As a result of the survey on the aging of Ulsan industrial complex in Korea, which carries out proper inspection, many of the facilities have been used for 20 years. Also, most of the facilities where the accident occurred have been in operation for more than 20 years. Therefore, this study suggested criteria for classifying devices that have exceeded a certain period of use as obsolete facilities. In addition, quantitative risk assessment was conducted. The safety investment method using the cost-benefit analysis method was proposed in order to calculate the loss cost and reduce the risk by expressing the risks of the corresponding aged facility as an Economic index. By utilizing the method of cost-benefit analysis of old facilities using the quantitative risk assessment presented in this study, it can be expected to improve the performance and life of old facilities, improve production efficiency and reliability of the system of facilities, change the recognition of safety management costs, increase employee stability, and reduce loss costs.

• (The)Study of the Eastern Classic
• /
• no.50
• /
• pp.7-28
• /
• 2013

The present study examines some essays by Yi Seol (李?, 1850-1906; pen name Bogam), a government official at the end of the Joseon Dynasty. Written in Classical Chinese, the essays are contained in The Collected Essays of Bogam (Bogam munjib). The study begins with a brief review on the Yeonan Yi Clan to which the official's family belonged, and then on his personal life history. The study goes on to analyze the contents of Yi's essays, which are classified into two themes: 1) his affirmation of the contemporary idea that saw the world as divided into the Chinese and the Barbarians, which justified and reinforced his resistance against Japan; and 2) his views on how to regain social stability. Concerning the former theme, Yi asserts that Joseon should not betray Qing China and should purge his nation of Japanese influence. Naming Japan as the evil enemy of Joseon, Yi expresses his firm resistance against the neighboring nation. As for the latter theme, his essays put forth an array of suggestions on how to disband the Donghak rebels, who emerged at the end of Joseon, and how to restore people displaced in the aftermath of social uprising. Although the suggestions are mostly general ones, he repeatedly stresses the importance of social stability in some of his essays addressed to the king.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.4
• /
• pp.475-481
• /
• 2018

In this study, the safety and effectiveness of ope cutter, developed to prevent frequent accident propeller windingness at sea. First, we calculated the bolt strength of the three types of rope cutting devices used in the experiment and the torsional stresses on the shafting system theoretical equation and the finite element method. As a result, the bolts used in the rope cutter confirmed from the viewpoint of safety life design and fail safe design. Also, safety satisfactory because of the small effect on the shaft system when locking up. Experiments were carried out to cut ropes and fishing nets from the sea using the ships equipped with three types of rope cutters verified to be safe. As a result, ropes of 20 to 50 mm in thickness were generally cut. It was found that the cutting efficiency of a rope cutter attached to shafting decreased when cutting thick ropes.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.175-180
• /
• 2018

In this study, CFRP was manufactured with the laminate angle of $45^{\circ}$. The specimen of TDCB bonded with the adhesive for structure was designed by CATIA and the analysis was progressed by using the finite element analysis program of ANSYS. This study model was designed on the basis of British industry and ISO standard and the configuration factor(m) was established with variable according to the angle of model configuration. As the study result of this paper, the maximum deformations at the specimens with the tapered angles of $4^{\circ}$ and $8^{\circ}$ become most as 12.628 mm and least as 12.352mm respectively. Also, the maximum equivalent stresses at the specimens with the tapered angles of $6^{\circ}$ and $8^{\circ}$ become most as 9210.3 MPa and least as 4800.5 MPa respectively. The damage data of TDCB structure with the laminate angle which was manufactured with CFRP could be secured through this study result. As the damage data of TDCB structure bonded with CFRP obtained on the basis of this study result are utilized, the esthetic sense can be shown by being grafted onto the machine or structure at real life.

• (The)Korea Educational Review
• /
• v.18 no.1
• /
• pp.253-281
• /
• 2012

This qualitative study explores how Mongolian migrant workers, with a marked tendency for family migration, plan and put into practice their child's education and attach meaning to it in relation to the social network they form during their stay in Korea. Specifically, it analyzes in particular ways the social network Mongolian migrant workers form affect their settlement in Korea, the process by which the social network affects their planning of their child's education, and how the education planning and its realization lead to the formation of new social networks. The results show that parents were divided between those who made a deliberate decision in sending their child to the Seoul Mongol School as a part of their plan and those who chose the school due to forced circumstances. While some parents preferred the Seoul Mongol School over regular Korean schools for their child's education and future, others sent their child to the Seoul Mongol School, regardless of their preference, because they did not have access to information about regular Korean schools, were afraid of divulging their illegal status, or were afraid their child would not be able to adjust to the school life in Korean schools. Based on such analysis, this paper stresses the urgency of further research in this area, and suggests direction for future policy measures.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.7
• /
• pp.439-446
• /
• 2020

This study aimed at developing a convergence education program about skin care and social welfare with the purpose of operating liberal arts courses to foster the creativity and character building of university students and the development findings are as follows. The name of the developed course is "beauty treatment welfare and community service" and details were developed for the course overview, goals of the course, textbooks, course management, assignments, and assessment. The lesson goals of this course are character building by fostering creative and outstanding individuals demanded by the society and equipped with the basic knowledge of majors like skin care and social welfare as well as the capability to share and consider through service learning related education for the increase in convergence critical thinking skills and the convergence of skin care and social welfare. The details of the course comprised of introduction about the course, understanding the concept of convergence, understanding the concepts of skin care and social welfare, convergent thinking education and practicum, and education about service learning performance sharing meeting. The service learning is targeted on the socially disadvantaged, such as children and elders, and students can engage in service twice a week with 3 hours for each service session. The assessment is evaluated with midterm (30%), final exam (30%), report (20%), and attendance (20%). This study stresses importance on the development of a convergence education program for skin care and social welfare, which are still undeveloped while convergence education is expanding in university, and with this research as the start, it is anticipated for various approaches to be actively implemented about convergence education in the field of beauty treatment.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.7 no.2
• /
• pp.427-435
• /
• 2017

Most of the domestic city buses are equipped with the pressure vessels subjected to internal pressure applied by compressed natural gas. Pressure vessels subjected to internal pressure are used in various forms and purposes. Fuel is explosive and has flammable high pressure. The damage of the pressure vessel causes many property damage and loss of life. Safe design for pressure vessel is always necessary. Due to these reasons, many studies using finite element analysis have been conducted. In this paper, the stresses of cylindrical vessel and spherical dome were analyzed using ANSYS, a finite element analysis software. In order to verify the validity of the analysis, a model with a perfectly spherical shape of the dome was designed and observed. Based on the ASME standard in used, stress distribution was also analyzed for models designed with compressed natural gas(CNG). The FEM analysis software agreed with the theory when the dome shape was perfectly spherical. The model designed based on the ASME specification theory, stress concentration occurred in the knuckle part.

• Journal of the Korean Society of Food Culture
• /
• v.23 no.3
• /
• pp.318-327
• /
• 2008

This study examined the cultural dietary habits as well as attitudes toward food, within other life pattern elements, of students living in Gwangju City and Chonnam Province, Korea. Questionnaires from 1,000 student respondents were analyzed. The survey consisted of questions regarding physical condition and health status, dietary consciousness, food preference, knowledge of food and nutrition, and dietary culture. The results showed that 1.6% of the students considered their own physical condition to be extremely poor, and 2.7% and 2.1% also considered their father's and mother's physical conditions as extremely poor, respectively. Among the respondents, 18.3% were smokers and consumed an average of 14.8 cigarettes per day. With regard to their dietary habits, the students answered that they preferred to eat meals with friends rather than with family members, fruit was chosen for eating over health food supplements, and there was very little participation or interest in various food and cultural festivals. The female students had a tendency to alleviate mental stresses by eating, while the male students performed more physical activity to deal with stress. The female students also preferred cereal, fruit, fast food, and sweetened foods more than the male students. Between the smokers and non-smokers, significantly more non-smokers chose fruit (p<0.01), ethnic foods (p<0.05), and sweetened foods (p<0.05) as compared to the smokers. Body mass index (BMI) had significant positive correlations with soft drink (p<0.01), health food supplement (p<0.01), and alcoholic beverage (p<0.001) consumption, while BMI was negatively correlated with cereal (p<0.01), fruit (p<0.001), and sweetened food (p<0.01) intake. The health status of students was positively correlated with their father's health status (p<0.01), mother's health status (p<0.001), and BMI (p<0.05), as well as cereal (p<0.001), high protein side dish (p<0.01), fruit (p<0.01), vegetable (p<0.01), and traditional food (p<0.001) intake. The average body weight for female students was approximately 5 kg less than the Korean Nutrition Society's standardized weight, therefore, it is strongly recommended that measures be taken to develop a systematic nutrition education program that would help those students who often unintentionally skip breakfast or go on extreme diets to improve body image.