• Title/Summary/Keyword: class A

Search Result 19,743, Processing Time 0.045 seconds

Dynamic Behavior of Reactor Internals under Safe Shutdown Earthquake (안전정기지진하의 원자로내부구조물 거동분석)

  • 김일곤
    • Computational Structural Engineering
    • /
    • v.7 no.3
    • /
    • pp.95-103
    • /
    • 1994
  • The safety related components in the nuclear power plant should be designed to withstand the seismic load. Among these components the integrity of reactor internals under earthquake load is important in stand points of safety and economics, because these are classified to Seismic Class I components. So far the modelling methods of reactor internals have been investigated by many authors. In this paper, the dynamic behaviour of reactor internals of Yong Gwang 1&2 nuclear power plants under SSE(Safe Shutdown Earthquake) load is analyzed by using of the simpled Global Beam Model. For this, as a first step, the characteristic analysis of reactor internal components are performed by using of the finite element code ANSYS. And the Global Beam Model for reactor internals which includes beam elements, nonlinear impact springs which have gaps in upper and lower positions, and hydrodynamical couplings which simulate the fluid-filled cylinders of reactor vessel and core barrel structures is established. And for the exciting external force the response spectrum which is applied to reactor support is converted to the time history input. With this excitation and the model the dynamic behaviour of reactor internals is obtained. As the results, the structural integrity of reactor internal components under seismic excitation is verified and the input for the detailed duel assembly series model could be obtained. And the simplicity and effectiveness of Global Beam Model and the economics of the explicit Runge-Kutta-Gills algorithm in impact problem of high frequency interface components are confirmed.

  • PDF

An Investigation of Insect Pest and Maximum Occurrence Period of Key Pest Insect on Stored Rice Grains (미곡저장해충의 분류동정 및 주요저장해충의 발생최성기 조사 연구 -전남지방중심-)

  • 김규진;김선곤;최현순
    • Korean journal of applied entomology
    • /
    • v.27 no.2
    • /
    • pp.117-124
    • /
    • 1988
  • An Investigation of insect pests in rice stored was carried out in Jeonnam region of Korea. The total of 2 class, 7 orders 16 families and 25 species were recorded in Lepidoptera; 8, Coleoptera; 11, Orthoptera; 1, Thysanura 1, blattaria; 2, Hymenoptera; 1 and mites; 2 spe-cies. The important species among them were Sitotroga cerealella, Ephestia cautella, Paral-ipsa gularis, Poldia, in Lepidoptera, and Sitophilus orzae, Oryzaephilus surianmensis, Cryptolestes ferrugineus, Tribolium castaneum, Tenebroides mauritanicus, Attagenus japonicus, in Coleoptera and Blatella germanica, in Blattaria and Acarus siro Petrobia latens, in mites. The duration of maximum occurrence were the late June to mid July for Sitotroga cerealella, the mod July to early August for Oryzaephilus surianmensis the mid July to August for Tribolium castaneum, the early July to late July for Sitophilus orzae, the mid June to early July for Attagenus japonicus the mid June to late Spetember for Blatella germanica and the late April to late May for Acarus siro and Petrobia latens, respectively in investigation, Blatella germanica(Blattaria) which was no problem in stored rice insect till now was mainly distributed a coastal plain and period of occurrence was long amount of occurrence was great. Rice weevil has 4 generations under natural conditions and the peak of 1st perood time was ranged from middle of jun. to last decade of Jun., 2nd period was from the lats decade of Jul. to first decade of Aug., 3rd period was from middle of Sep. to late Sep., 4th period was middle of Oct. to early Nov.

  • PDF

Plans for Teaching and Learning of Learner-centered Activities in Korean Verse Education (시조교육의 현황과 학습자 활동 중심의 교수$\cdot$학습 모형 - 고등학교 국어 교과서 수록 작품 <시조>를 중심으로 -)

  • Kang Myong-Hye
    • Sijohaknonchong
    • /
    • v.20
    • /
    • pp.141-171
    • /
    • 2004
  • Even though only 3 sijo are in high school textbook. through these 3 sijo each type can be understood in that each represents pyung sijo, sasul sijo, and present sijo. To learn with learner-centered activities, which aim for full knowledge acquisition regarding literary works, as the preparing stage, students can learn what theyll learn by teachers. Sijo are, so to speak, formed with three chapters, and stand for the world that is colorless, scentless, and flavorless. So, the theme can be found with ease. Compared with other genres, sijo can be formed creating background with ease. Moreover, sijo are not too long, so learners can paraphrase it. Sijo that express private experiences with the everyday language can be related to other genres or everyday language. So, sijo are last to present. In the teaching phase, on the gradation of concretion and gradation, writing or presentation activities are presented. After classroom, learners keep a reaction journal. In the phase of concretion and gradation, learners can apprehend that typical differences of the emotions of poetic speakers is from typical differences, even though emotions of poetic speakers of (1)$\cdot$(2)$\cdot$(3) that is each stand for pyung sijo, sasul sijo, and present sijo are roughly summarized loneliness, desolateness, and gloominess. Moreover, these typical differences are from social, political. and cultural settings, namely, the differences of contexts. In this teaching model. learners should prepare for content regarding context and text before the class. Teachers should act as an assistant to help learners pre-understand their subjective experiences and imaginations.

  • PDF

Bronchial Responsiveness in Patients with Mitral Valvular Heart Disease (승모판 심장질환 환자에서 기관지 반응성에 대한 연구)

  • Kim, Ho-Cheol;Kim, Min-Gu;Hwang, Young-Sil
    • Tuberculosis and Respiratory Diseases
    • /
    • v.42 no.5
    • /
    • pp.752-759
    • /
    • 1995
  • Background: Bronchial asthma is characterized by noctunal dyspnea, cough and wheezing because of airway hyperresponsiveness to nonspecific stimuli. These symptoms and signs are also observed in patients with congestive heart failure. Therefore, this is so called "cardiac asthma". There are lots of experimental and clinical datas to suggest that airway dysfunctions occur in acute and chronic congestive heart failure. However, it is still controversial whether bronchial hyperresponsiveness is present in patients with congestive heart failure. To assess whether bronchial hyperresponsiveness is present in patients with congestive heart failure and to demonstrate the relationship between bronchial responsiveness and vascular pressure, we performed methacholine provocation test in 11 patients with mitral valvular heart disease. Methods: All patients were in the New York Heart Association functional class II and treated continuously with digoxin and/or dichlozid and/or angiotensin converting enzyme inhibitor except one patient. All patients were undergone right and left side heart catheterization for hemodynamic measurements. A 20 percent fall of peak expiratory flow rate were considered as positive response to methacholine provocation test. Results: 1) Only one patient who has normal pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index was positive in methacholine provocation test. 2) Their mean pulmonary artery pressure, pulmonary capillary wedge pressure were $21.72{\pm}9.70mmHg$, $15.45{\pm}8.69mmHg$ respectively which were significantly higher. Conclusion: It is speculated that in stable congestive heart failure patients, bronchial responsiveness as assessed by methacholine provocation test may not be increased.

  • PDF

Middle School Home Economics Teachers' Perception and Needs of Self Supervision Related to Home Economics Subject Matter (중학교 가정과교사의 가정교과관련 자기장학에 대한 인식과 자기장학 활성화를 위한 요구)

  • Nam, Yun-Jin;Chae, Jung-Hyun
    • Journal of Korean Home Economics Education Association
    • /
    • v.20 no.1
    • /
    • pp.45-62
    • /
    • 2008
  • The purpose of this study was to investigate middle school home economics(HE) teachers' perception and needs on self supervision related to HE subject matter, Using the methods of survey and interview, 177 samples were collected. For collected surveys, mean value, standard deviation, frequency, percentage analysis were performed by using an SPSS/Win (ver10.1) program. The results of this study were as follows. First, the middle school HE teachers recognized that self supervision related to HE subject matter was absolutely needed to expand the improvement of techniques for teaching instructions and the width of knowledge on the studies on textbook. Second, the middle school HE teachers recognized the necessary parts of self supervision related to HE subject matter as HE teaching-learning methods, the studies on textbook contents, and HE education philosophy in order. Third, the middle school HE teachers recognized that it would be helpful in improving their HE class and expertise in order of field survey, participation in various training programs, utilization of mass media, participation in societies for researches and meetings and information sharing with co-teachers among the types of self supervision. Fourth, the middle school HE teachers needed the reduction in miscellaneous duties, less pressure for time, restoration of teachers' desire, support of physical resources (improvement of various environments such as classrooms and special rooms), economic support and various support programs (expanding the opportunities to participate in training and society and establishment of a database for relevant materials, etc.) to facilitate self supervision. As such, the middle school HE teachers' overall recognition on HE-related self supervision became significantly higher. To enhance the HE-related expertise, however, it would be necessary to conduct concrete and active support for HE education, philosophical area and the studies on textbook contents as well as the teaching-learning methods for HE in which teachers' demand was high. In addition, the HE teachers wanted to have an easy and quick access to various HE-related data; therefore, it would be urgent to summarize scattered relevant data and support the HE teachers more systematically.

  • PDF

Analysis on Distribution Characteristics of Mammals in Relation to Altitude in Juwangsan National Park (주왕산국립공원에 서식하는 포유동물의 고도에 따른 분포 특징의 분석)

  • Chung, Chul-Un
    • Journal of Ecology and Environment
    • /
    • v.29 no.6
    • /
    • pp.511-520
    • /
    • 2006
  • The study analyzed the distribution of mammalia per altitude in Gamebong, the highest trail of Juwangsan National Park and confirmed the inhabitation of 22 different species inhabiting in the park. Starting from 200 m to 800 m above the sea level was segmented into 100 m unit. The result of analysis has shown that the Tamias sibiricus is the dominant specie throughout in all segments. Species confirmed to be inhabiting in all segments of research areas were Mustela sibirica, Caproelus pygargus and squirrel. By analyzing the confirmed Field Sign basing from the observation point, it has shown close relations between types of species and population following the increase in altitude (y=-0.0234 + 25.552, $R^2$=0.9296, $F_{0.05}$(1,4)=7.71, p<0.05). However, the result of analysis targeting nine species inhabiting in at least five out of six 100 m segmented units has shown that only two species, Apodemus sgrarius (y=-0.034X+25.2, $R^2$=0.905, $F_{0.05}$(1, 4)=38.169, p<.0.01) and Sciurus vulgaris (y=-0.0154X+ 12.819, $R^2$=0.781, $F_{0.05}$(1, 4)=14.270, p<0.05) were affected by the altitude. Therefore, it is judged that the distribution of species does not follow the altitude variation but follows the food conditions and the structure of habitat. The result of analysis of Box and Whisker Diagram had shown lowest quartile deviation($Q_U-Q_L$) in Nature Restoration Area that is located in $200{\sim}300m$ above the sea level, where hikers are prohibited from entering. In $500{\sim}600m$ above the sea level segment that has similar food environment and trail, it has shown the widest distribution. Further research is required on this segment for the excretion drops of Prionailurus bengalensis, a Grade II class of endangered species, were found on the trails.

Comparison of Mathematics and Science Teachers' Perception on the Korean Gifted education of Institutes for the Gifted education in the City Office of education and Science High School (시교육청 영재교육원과 과학고 영재교육원 수학, 과학 교사의 영재교육에 대한 인식 비교 연구)

  • Hwang, Jung-Hoon
    • Journal of Gifted/Talented Education
    • /
    • v.20 no.3
    • /
    • pp.809-830
    • /
    • 2010
  • The purposes of this study are to investigate Korean mathematics & science teachers' perception on the special education for the gifted, and to investigate if there are differences on their perception about it among the mathematics & science teachers when their affiliation institutes for the gifted are different. Their affiliation institutes for the gifted education are divided into two groups, which are the city office of education, and science high school. The research problems of this study are as follows. Firstly, are there any differences of their perception according to their affiliation institutes for the gifted education are divided into two groups, which are the city office of education, science high school? Secondly, are there any differences of their perception according to their affiliation institutes for the gifted education are divided into two groups, which are the mathematics teachers, science teachers? For the study, 26 mathematics teachers & 36 science teachers were sampled from the Institutes for the Gifted Education in Busan Metro-city & the Busan Science High School. and then 34-item-questionnaire developed by the author was administered to them. The research results are as follows. Firstly, the question as to participation in special education for the gifted in mathematics & science, the positive answer has been dominant. Teachers who were going to participate in special education for the gifted in mathematics & science have answered affirmatively. Secondly, perception of the organization of a class of the gifted in mathematics & science is very different between the group of institutes for the gifted education in the city office and the group of institutes for the gifted education in the science high school. Thirdly, perception of selection of gifted students for special education for the gifted in mathematics & science is very different between group of the mathematics teachers and group of the science teachers. Fourthly, 46.7% of the total agree with management of the gifted education in the science high school, 46.7% of the total agree with separation of management about mathematics & science.

Contents analyses of teaching·learning research on housing education of home economics for secondary schools (중등학교 주생활교육 교수·학습 개발연구 내용분석)

  • Joo, Hyunjung;Cho, Jaesoon;Choi, Yoori
    • Journal of Korean Home Economics Education Association
    • /
    • v.29 no.3
    • /
    • pp.33-48
    • /
    • 2017
  • The purpose of this research was to analyze the contents of housing teaching learning studies in Home Economics of secondary schools since 2001. The 22 research, drawn from the database 'riss4u', were analyzed in terms of general information of the paper (studied institution & year, implementation & evaluation, subject of study & size) and specific contents of teaching learning plans (theme, curricula & textbooks, methode & # of lessons, resources). The results showed that most studies were reported during the 7th or the 2007 revised curricula period. All, except one doctoral dissertation, were master's theses from a few universities. In all studies, ranging from 2 to 15 lessons, teaching learning plans were implemented and evaluated in the class of the researcher while some were applied in other schools, too. The theme of the teaching learning plans varied but were concentrated on one out of two content elements and two out of six learning elements. The 2007 revised curriculum seems to be an important turning point, not only reinforcing the analyses of the curricular and textbooks in the analyzing stage but also facilitating the use of various methods for the lessons in the developing stage. Practical problem based model was the most frequently adopted, while cooperative learning and ICT served as fundamental although not always mentioned. Various teaching resources such as UCC, reading materials, PPT were developed for the teacher. Activity sheets were the most frequently used for the students, followed by reading materials. Because teaching learning is an essential core of education, teaching learning studies should be more actively conducted and the variety of subject topics, methods and resources should also be obtained by more researchers.

Analysis of Competency of Nursing Teacher in Specialized Vocational High School (특성화고등학교 간호과 교사의 역량 분석)

  • Yoon, In-Kyung;Jang, Myung-Hee;Kwak, Mi-sun;Park, Ji-Young
    • Journal of vocational education research
    • /
    • v.37 no.3
    • /
    • pp.85-111
    • /
    • 2018
  • The purpose of this study is to derive the competence of nursing teacher in Specialized vocational high school. The knowledge, skills, and attitudes required for the nursing teachers were verified and the competency groups and sub-competencies were verified and priorities were suggested. To do this, 23 nursing teachers who were currently working in the Specialized vocational high school were selected as expert panels and the study was conducted using Delphi and Layered Analysis(AHP) technique. The results of this study were as follows. First, the competency group of the nursing teacher in Specialized vocational high school showed teaching and learning methods & techniques, student guidance, curriculum development and operation, school management support, industry-academy cooperation, self-development and professionalism improvement. The total number was 6. Second, the sub-competency is composed of knowledge and skills related to the curriculum, planning and preparation of instruction, instruction operation, guidance of experiment and practice, instruction evaluation, development and utilization of teaching and learning medium, instruction environment, guidance on student education activities outside the curriculum, career guidance, life guidance, class management, guidance of technology and qualification, development of school curriculum, organization and operation of school curriculum, planning and operation of field practice, work planning, school management support, teacher evaluation and personnel management support, leaning support(practice place and equipment), establishment and operation of industry-academia cooperation, strengthening community cooperation, public relations in the school(department), field research for improvement of educational activities, participation in conferences and training, exploration of new knowledge and technology, The total number was 26. The most important of the relative importance was the curriculum development and operation. The subordinate competencies that have a high priority in each competency group were guidance of experiment and practice, guidance of technology and qualification, planning and operation of field practice, leaning support(practice place and equipment), management and work planning, establishment and operation of industry-academia cooperation, exploration of new knowledge and technology. The competency system derived from this study will be applied to the training and evaluation of nursing teachers in the future and can be used as basic data for related research.

Analyzing Self-Introduction Letter of Freshmen at Korea National College of Agricultural and Fisheries by Using Semantic Network Analysis : Based on TF-IDF Analysis (언어네트워크분석을 활용한 한국농수산대학 신입생 자기소개서 분석 - TF-IDF 분석을 기초로 -)

  • Joo, J.S.;Lee, S.Y.;Kim, J.S.;Kim, S.H.;Park, N.B.
    • Journal of Practical Agriculture & Fisheries Research
    • /
    • v.23 no.1
    • /
    • pp.89-104
    • /
    • 2021
  • Based on the TF-IDF weighted value that evaluates the importance of words that play a key role, the semantic network analysis(SNA) was conducted on the self-introduction letter of freshman at Korea National College of Agriculture and Fisheries(KNCAF) in 2020. The top three words calculated by TF-IDF weights were agriculture, mathematics, study (Q. 1), clubs, plants, friends (Q. 2), friends, clubs, opinions, (Q. 3), mushrooms, insects, and fathers (Q. 4). In the relationship between words, the words with high betweenness centrality are reason, high school, attending (Q. 1), garbage, high school, school (Q. 2), importance, misunderstanding, completion (Q.3), processing, feed, and farmhouse (Q. 4). The words with high degree centrality are high school, inquiry, grades (Q. 1), garbage, cleanup, class time (Q. 2), opinion, meetings, volunteer activities (Q.3), processing, space, and practice (Q. 4). The combination of words with high frequency of simultaneous appearances, that is, high correlation, appeared as 'certification - acquisition', 'problem - solution', 'science - life', and 'misunderstanding - concession'. In cluster analysis, the number of clusters obtained by the height of cluster dendrogram was 2(Q.1), 4(Q.2, 4) and 5(Q. 3). At this time, the cohesion in Cluster was high and the heterogeneity between Clusters was clearly shown.