• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.180-187
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• 2004

The miniaturization technologies are perceived as potential key technologies of the future. They will bring about completely different ways in which people and machines interact with the physical world. However, at the present time, the primary technologies used fur miniaturization are dependent on the microelectronic fabrication techniques. The principal shortcomings associated with such techniques are related to the inability of to produce arbitrary three-dimensional features not only in electronics but also in a wide range of metallic materials. In this paper, a ultramicro-stereolithography system assisted with a femto-second laser was developed to fabricate the arbitrary three-dimensional nano/micro-scaled features. In the developed process, a femto-second laser is projected according to CAD data on a photosensitive monomer resin, it induces polymerization of the liquid resin. After the polymerization, a droplet of ethanol is dropped to remove the liquid resin and then the polymerized nano-scaled features only remain. By a newly developed process, miniature devices for an extremely wide range of applications would become a technologically feasible reality. Some of nano/micro-scaled features as examples were fabricated to prove the usefulness of this study at the fundamental stage.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.582-590
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• 2020

This paper aims to analyze and introduce the primary English curriculum of North Korea reformulated according to the New Educational Program. Sources for analysis are the 4th and 5th primary school English syllabus based on the New Educational Program, explanations of the New Educational Program appeared in People's Education and Kim, Jeong-Il's selected writings. The analytical sources are classified into characteristics, objectives, contents, methods and evaluation. The findings are as follows: The primary English education aims to reach to the basis of middle school English by learning English alphabets and basic English expressions. 4th graders learn basic oral English such as pronunciation, stress and intonation for the first semester and learn English alphabets and their sounds for the second semester. 5th graders learn familiar topics in English and repeatedly practice the important components of English such as pronunciation, vocabulary and grammar. The method is to maintain students' interests in English and encourage students to use classroom English. Also, structural practice is an important part of the method. Evaluation is primarily process-oriented and must motivate students to excel in English rather than fail in English.

• Journal of Digital Convergence
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• v.18 no.8
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• pp.133-149
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• 2020

The purpose of this study was to investigate the effect of perceived risk on continuous usage intention of Internet primary banks and to verify moderating effects of acceptance factors affecting customers' acceptance of Internet primary banks on the relationship between perceived risk and continuous usage intention. The study aims to find ways to cope with perceived risk and strategic measures of intention in order to increase the intention to continuous usage intention of Internet primary banks. For the analysis, interaction effect were conducted among a total of 457 surveys. As a results, First, perceived risks, acceptance factors and continuous usage intention of the customers of Internet primary banks were significantly correlated. Second, the types of perceived risks which have a significant effect on continued usage intention of Internet primary banks were found to be perceived financial and functional risks. Third, respect to moderating effects of moderator variables, usefulness was found to have a significant moderating effect on the relationship between perceived security risk and continuous usage intention. In addition, ease of use was shown to have a significant moderating effect on the relationship between each type of perceived risks and continuous usage intention. This study attempted to explore and seek strategies to reduce perceived risks and strategic plans for acceptance factors to increase continuous usage intention of Internet primary banks.

• Korean Journal of Comparative Education
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• v.27 no.4
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• pp.73-96
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• 2017

This study aims to investigate the primary teachers' perception of social emotional learning (SEL) in Malawi. To achieve this purpose, total 78 questionnaires were gathered from 9 primary schools in rural area. The data was analyzed with independent-samples t-test, correlation analysis, and multiple regression analysis. The results of this study are follows. First, the sub-factors of the Malawian primary teachers' perception of SEL shows that Comfort is 4.10, Commitment is 4.59, and Culture is 3.78. Second, there was a significant difference in the Malawian primary teachers' perception by age, years of teaching, and participation to in-service training about SEL among the individual characteristics. Third, the Malawian primary teachers' degree of implementation of SEL in school was 4.01, and there was a significant difference by years of teaching. Forth, among the sub-factors of teachers' perception of SEL, Comfort had a positive effect on the degree of implementation of SEL. This result implied that the reason why Malawian primary teachers had difficulty in implementing SEL in the school might be not a lack of individual competence but feel uncomfortable with implementation. Therefore, in order to implement SEL in the Malawi school, it is necessary to support teachers so they have confidence and comfort psychologically.

• Journal of the Korean Society of Earth Science Education
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• v.14 no.3
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• pp.236-247
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• 2021

This study is to investigate the effect of pre-primary teachers' gender and earth science completion while attending high school on the diversity of concepts, the level of conceptual understanding, and misconceptions about seasonal changes. This study was conducted with 71 pre-primary teachers. The conclusion of this study is as follows. First, the area of concepts used by pre-primary teachers to explain seasonal changes showed a greater difference depending on whether or not they completed earth science while attending high school, rather than depending on gender. Second, although there was no significant gender difference in the conceptual level of pre-primary teachers for seasonal change, the group who completed earth science while attending high school had a statistically significantly higher level of conceptual understanding than the group that did not complete it. Third, the ratio of misconceptions related to seasonal change of pre-primary teachers by gender was not significant, but the group who did not complete earth science while attending high school had a statistically significantly higher percentage of misconceptions than the group that completed it. As a result of the above examination, it is judged that the area of concepts, the level of conceptual understanding, and the misconceptions about seasonal changes of pre-primary teachers are more affected by the completion of earth science courses during high school than by gender differences.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.249-262
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• 2022

This study was conducted on the alternative concept of elementary school pre-service teachers to seasonal changes. From May 2021 to June 2022, it was conducted with 60 pre-primary teachers at P National University of Education. The conclusion of this study is as follows. First, pre-primary teachers explained the cause of seasonal changes, and out of 60 pre-primary teachers, only 22 (36%) had scientific concepts, and the remaining 38 (64%) students had alternative concepts. Second, in explaining how the inclination of the Earth's axis of rotation is related to seasonal changes, only 16 (27%) of the 60 pre-primary teachers had a scientific concept, and the remaining 44 (73%) had alternative concepts. Third, pre-primary teachers explained the relationship between the change in the solar altitude and the seasonal change. Among 60 pre-primary teachers, 12 (20%) had a scientific concept, and the remaining 48 (80%) had alternative concepts. Fourth, looking at the comprehensive types of alternative concepts for seasonal changes, the aS-bS-cS type, which is classified as a type that explains the causes of seasonal changes using scientific concepts as a whole, was 8(13%) out of 60 pre-primary teachers. and the remaining 52 (87%) had at least one alternative concept to explain seasonal changes.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.519-525
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• 2010

Ectopic eruption means the eruption of the tooth in an abnormal position due to multiple factors, which found most frequently in maxillary fist permanent molars, mandibular lateral incisors and maxillary permanent canines. Ectopic eruption of the maxillary first permanent molar occurs when the molar erupts with a more mesial angulation than normal, and locks itself in an atypical resorption on the distobuccal root of the second primary molar. The maxillary first permanent molar plays important roles for mastication and occlusion, so ectopically erupted maxillary first permanent molars should be relocated into proper position. Treatment options are separation by insertion of the brass wire or elastic rings, preparation of distal aspect of the maxillary second primary molar, using fixed or removable appliance with finger spring, and placement of space maintainer or space regainer after extraction of the maxillary second primary molar. We report three cases treated of ectopically erupted maxillary first permanent molar by re-setting of stainless steel crowns, placement of brass wire and using active plate. We could find out distal movement of maxillary first permanent molars into proper position and normal occlusion.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.696-706
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• 2003

The purpose of this study was to clarify the palatal forms through palatal curvatures of right to left, anterior to posterior direction, and difference of right and left palatal volumes in the primary and permanent dentition. Samples were consisted of normal occlusion of both dentition(50 males and 50 females each). Their upper plaster casts were used, measuring points were decided, through 3-dimensional laser scanning(3-D Laser Scanner, DS4060, LDI, U.S.A.), and fitting standard horizontal plane were made for measuring the height and sectioned volumes of palate. The results were as follows: 1. Palatal volume and height were greater at the right side of the palate in the primary and permanent dentition of male and female, but there was no significance. 2. Palatal height was greater in male compared to female, especially, there was significant difference at intercuspid, inter-second premolar area in the permanent dentition(P<0.05). 3. To the height of A-P direction of mid-palatal area, the highest point was 20mm in the primary dentition, 30mm in the permanent dentition from interdental papilla of central incisors. 4. Palatal height of inter-cuspid and inter-second premolar became shallow and broad, high and broad each, compared to inter-deciduous canine and inter-second deciduous molar.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.417-420
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• 2017

Hookworm infections are rare causes of acute gastrointestinal bleeding. We report a middle aged man with primary nephrotic syndrome and pulmonary embolism. During the treatment with steroids and anticoagulants, the patient presented acute massive hemorrhage of the gastrointestinal tract. The results of gastroscopy showed red worms in the duodenum. Colonoscopy and CT angiogram of abdomen were unremarkable. Capsule endoscopy revealed fresh blood and multiple hookworms in the jejunum and ileum. Hookworms caused the acute intestinal bleeding. The patient responded well to albendazole. Hematochezia was markedly ameliorated after eliminating the parasites. Hence, hookworm infection should be considered in the differential diagnosis of a patient with obscure gastrointestinal bleeding. Capsule endoscopy may offer a better means of diagnosis for intestinal hookworm infections.

• Tuberculosis and Respiratory Diseases
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• v.38 no.1
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• pp.34-44
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• 1991

Restoration of skin reactivity to 1 TU of tuberculin (RT23) by repeated tests at 10 days interval has been investigated in the BCG vaccinated or unvaccinated primary school children. The results obtained are as follows. 1) Tuberculin reactors showing 6 mm or larger induration to the first tests were 20.0% in the first grade school children and 33.3% in the sixth grade children. Six millimeter or larger reaction than that of the first reaction was found in 14.9% of the first grade children and in 34.6% of the sixth grade children. 2) Six millimeter or larger reactors were 10.8% of the first grade children without BCG scar against both first and second tests and 11.8% of the sixth grade children on first tests and 10.6% on second tests. There was none or very few, if any, in number of 6 mm or larger difference between the first and second tests among children without BCG scar. In addition, there was no children shown 6 mm or larger second reaction than that of the first reaction and thus those reactors seemed to be natural infection. 3) From questionaire survey, parents of 73.3% of the first grade children and of 72.7% of the sixth grade children were aware of BCG vaccination of their children, while parents of 15.1% and 24.6% of the first and sixth grade children did not know their children's vaccination history even if children possessed BCG scar. 4) Of the first grade children whose parents remembered their BCG vaccination, 65.6% were vaccinated within 4 weeks after birth and 25.5% between 4 weeks and one year. Six millimeter or larger reaction on the first tests was observed in 20.2% of the former group and 15.9% of the latter group, however reactors on the second tests were 32.1% and 31.9% respectively. BCG scar was not observed in 13.9% of children. 5) The majority of children (87.3%) were vaccinated in the skin of deltoid area and some (7.7%) at buttock or other areas. Children received first vaccination at the health centers were 68.5% and 30.3% at hospitals. More than 5 mm reaction was found in 18.7% of the former children and in 15.0% of the latter children. From this study restoration of tuberculin reactivity by repeated tests was found very common among the vaccinated children and thus it should be taken into account for the vaccination policy if it is performed after tuberculin testing.