• Title/Summary/Keyword: theory theory

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Characteristic of Wave Diffraction and Reflection for Irregular Waves in SWASH Model Around Small Port Structures (소규모 항만 구조물 주변에서 불규칙파에 대한 SWASH 모형의 반사 및 회절)

  • Kwon, Kyong Hwan;Park, Chang Wook;Park, Il Heum;Kim, Jong Hoon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.6
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    • pp.468-477
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    • 2019
  • The numerical model of Boussinesq approximation, which is mainly used for evaluating the port calmness due to the irregular waves, has a limit of applicability of lattice size in ports such as marinas with narrow port openings of around 30m. The SWASH model controls the partial reflection according to the depth, porosity coefficient and structure size when applying the reflected wave incident on the structure and terrain. In this study, the partial reflection evaluation at the front of the structure according to the bottom shape and the shape of the structure are examined. In order to evaluate the reproducibility of the model due to the diffraction waves entering the term, the area of incidence at right angles and inclination of the structure is constructed and compared with the diffraction theory suggested by Goda et al. (1978). The experimental results of the sectional structure reflectances calculated as the depth mean show reflectances similar to the approximate values of the reflectances presented by Stelling and Ahrens (1981). It is considered that the reflected wave is well reproduced according to the control of the reflected wave at the boundary and the shape and topography of the structure. Compared with previous studies to examine the diffraction of the wave incident from the breakwater opening, the wave incidence angle and the shape of the diffraction wave are very similar to the theoretical values, but both oblique and rectangular incidence In the case where the direction concentration is small, the diffraction degree is underestimated in some sections with the crest ratio of 0.5 to 0.6.

Frege's Critiques of Cantor - Mathematical Practices and Applications of Mathematics (프레게의 칸토르 비판 - 수학적 실천과 수학의 적용)

  • Park, Jun-Yong
    • Journal for History of Mathematics
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    • v.22 no.3
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    • pp.1-30
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    • 2009
  • Frege's logicism has been frequently regarded as a development in number theory which succeeded to the so called arithmetization of analysis in the late 19th century. But it is not easy for us to accept this opinion if we carefully examine his actual works on real analysis. So it has been often argued that his logicism was just a philosophical program which had not contact with any contemporary mathematical practices. In this paper I will show that these two opinions are all ill-founded ones which are due to the misunderstanding of the theoretical place of Frege's logicism in the context of contemporary mathematical practices. Firstly, I will carefully examine Cantorian definition of real numbers and Frege's critiques of it. On the basis of this, I will show that Frege's aim was to produce the purely logical definition of ratios of quantities. Secondly, I will consider the mathematical background of Frege's logicism. On the basis of this, I will show that his standpoint in real analysis was much subtler than what we used to expect. On the one hand, unlike Weierstrass and Cantor, Frege wanted to get such real analysis that could be universally applicable. On the other hand, unlike most mathematicians who insisted on the traditional conceptions, he would not depend upon any geometrical considerations in establishing real analysis. Thirdly, I will argue that Frege regarded these two aspects - the independence from geometry and the universal applicability - as those which characterized logic itself and, by logicism, arithmetic itself. And I will show that his conception of real numbers as ratios of quantities stemmed from his methodological maxim according to which the nature of numbers should be explained by the common roles they played in various contexts to which they applied, and that he thought that the universal applicability of numbers could not be adequately explicated without such an explanation.

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Analysis of Slope Stability Considering the Saturation Depth Ratio by Rainfall Infiltration in Unsaturated Soil (불포화토 내 강우침투에 따른 포화깊이비를 고려한 사면안정해석)

  • Chae, Byung-Gon;Park, Kyu-Bo;Park, Hyuck-Jin;Choi, Jung-Hae;Kim, Man-Il
    • The Journal of Engineering Geology
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    • v.22 no.3
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    • pp.343-351
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    • 2012
  • This study proposes a modified equation to calculate the factor of safety for an infinite slope considering the saturation depth ratio as a new variable calculated from rainfall infiltration into unsaturated soil. For the proposed equation, this study introduces the concepts of the saturation depth ratio and subsurface flow depth. Analysis of the factor of safety for an infinite slope is conducted by the sequential calculation of the effective upslope contributing area, subsurface flow depth, and the saturation depth ratio based on quasi-dynamic wetness index theory. The calculation process makes it possible to understand changes in the factor of safety and the infiltration behavior of individual rainfall events. This study analyzes stability changes in an infinite slope, considering the saturation depth ratio of soil, based on the proposed equation and the results of soil column tests performed by Park et al. (2011 a). The analysis results show that changes in the factor of safety are dependent on the saturation depth ratio, which reflects the rainfall infiltration into unsaturated weathered gneiss soil. Under continuous rainfall with intensities of 20 and 50 mm/h, the time taken for the factor of safety to decrease to less than 1.3 was 2.86-5.38 hours and 1.34-2.92 hours, respectively; in the case of repeated rainfall events, the time taken was between 3.27 and 5.61 hours. The results demonstrate that it is possible to understand changes in the factor of safety for an infinite slope dependent on the saturation depth ratio.

Data Mining and Construction of Database Concerning Effects of Vitis Genus (산머루 관련 정보수집 및 데이터베이스의 구축)

  • Kim, Min-A;Jo, Yun-Ju;Shin, Jee-Young;Shin, Min-Kyu;Bae, Hyun-Su;Hong, Moo-Chang;Kim, Yang-Seok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.551-556
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    • 2012
  • The database for the oriental medicine had been existed in documentation in past times and it has been developed to the database type for random accesses in the information society. However, the aspects of the database are not so diversified and the database for the bio herbal material exists in widened type dictionary style. It is a situation that the database which handles the in-depth raw herbal medicines is not sufficient in its quantity and quality. Korean wild grape is a deciduous plant categorized into the Vitaceae and it was found experimentally that it has various medical effects. It is one of the medical materials with higher potentiality of academic study and commercialization recently because it has a bigger possibility to be applied into diverse industrial fields including the medical product for health, food and beauty. We constituted the cooperative system among the Muju cluster business group for Korean mountain wild grapes, Physiology Laboratory in Kyung Hee University Oriental Medicine and Medical Classics Laboratory in Kyung Hee University Oriental Medicine with a view to focusing on such potentiality and a database for Korean wild grapes was made a touchstone for establishing the in-depth database for the single bio medical materials. First of all, the literatures based on the North East Asia in ancient times had been categorized into the classical literature (Korean literature published by government organization, Korean classical literature, Chinese classical literature and classical literature fro Korean and Chinese oriental medicine) and modern literature (Modern literature for oriental medicine, modern literature for domestic and foreign herbal medicine) to cover the eastern and western research records and writings related to Korean wild grapes and the text-mining work has been performed through the cooperation system with the Medical Classics Laboratory in Kyung Hee University Oriental Medicine. First of all, the data for the experiment and theory for Korean wild grape were collected for the Medline database controlled by the Parliament Library of USA to arrange the domestic and foreign theses with topic for Korean wild grapes and the network hyperlink function and down load function were mounted for self-thesis searching function and active view based on the collected data. The thesis searching function provides various auxiliary functions and the searching is available according to the diverse searching/queries such as the name of sub species of Korean wild grape, the logical intersection index for the active ingredients, efficacy and elements. It was constituted for the researchers who design the Korean wild grape study to design of easier experiment. In addition, the data related to the patents for Korean wild grape which were collected from European Patent Office in response to the commercialization possibility and the system available for searching and view was established in the same viewpoint. Perl was used for the query programming and MS-SQL for database establishment and management in the designing of this database. Currently, the data is available for free use and the address is as follows. http://163.180.41.43:8011/index.html

Educational Needs of Elderly Hypertensive or Diabetes Patients and Educators for Education Program Development of Cardiocerebrovascular High-risk Group (심뇌혈관질환 고위험군 교육프로그램개발을 위한 노인 고혈압·당뇨병환자와 교육자의 교육요구도 및 지식수준에 대한 비교분석)

  • Lee, Hye-Jin;Kam, Sin
    • Journal of agricultural medicine and community health
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    • v.35 no.2
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    • pp.177-192
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    • 2010
  • Objectives: This study was conducted to examine the educational needs of elderly hypertensive or diabetes patients and educators for the education program development of cardiocerebrovascular high-risk group in community. Methods: This study was conducted with 60 hypertensive or diabetes patients aged 65 years or above (cardiocerebrovascular high-risk group) who had registered KHyDDI(Korea Hypertension Diabetes Daegu Initiative) Project and attended Hypertension Diabetes Intervention Center Program, and with 44 educators in the center between June and August, 2009. Data were collected using questionnaires including general characteristics, educational objectives, curriculum, contents, and methods. Results: The major findings of this study were as follows: In education methods, cardiocerebrovascular high-risk group and educators both preferred small-grouped(5-9 persons) or individual education, 30min-1 hour, 50%-50% of theory-practice ratio, 3 months of education. In education contents, both groups needed all the suggested contents. Five categories would be suggested for the development of education program. The first category was that there was no significant difference between cardiocerebrovascular high-risk group's needs and knowledge. The second was category of low knowledge level in cardiocerebrovascular high-risk group's knowledge. The repeated education would be necessary for this category. The third was category with large standard deviation in cardiocerebrovascular high-risk group's knowledge. Individual education would be necessary for this category. The fourth category was that there was significant difference between cardiocerebrovascular high-risk group's knowledge and knowledge assessed by educators. The improvement of educator's education skill would be necessary for this category. The fifth category was that there was significant difference between cardiocerebrovascular high-risk group and educator's needs. Conclusions: Small group or individualized and staged education reflecting above cardiocerebrovascular high risk group and educators' needs should be developed for more effective education to prevent and manage the cardiocerebrovascular disease.

Tropospheric Ozone over the Seoul Metropolitan Area Derived from Satellite Observations (MODIS) and Numerical Simulation (위성관측(MODIS)에서 유도된 수도권 지역의 대류권 오존 및 수치실험)

  • Yoo Jung-Moon;Park Yoo-Min;Lee Suk-Jo
    • Journal of the Korean earth science society
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    • v.26 no.3
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    • pp.283-296
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    • 2005
  • The effect of ozone and surface temperature on the ozone band at $9.7{\mu}m$ has been investigated from radiative transfer theory together with observations in order to derive empirical methods for remotely sensing ground-ozone concentration. Simultaneous observations of satellite (MODIS Aqua; ECT 13:30) and ground-ozone at 79 stations have been used over the Seoul Metropolitan Area (SMA; 125.7-127.2 E, 37.2-37.7 N) during four ozone-warning days in the year 2003. Cloud effect on the band in the methods was filtered out based on synoptic observations. Upwelling radiance values at $9.6{\mu}m$ which have been estimated at the given ozone concentration of 327-391 DU depend on surface temperature (Ts) showing $5.52\~5.78Wm^{-2}sr^{-1}\;at\;Ts = 290 K,\;and\;9.00\~9.57Wm^{-2}sr^{-1}$ Ts = 325K. Thus, the partitioned contributions of ozone and temperature to intensity of ozone absorption band are $0.26Wm^{-1}sr^{-1}/64\;DU\;and\;0.31 Wm^{-2}sr^{-1}/35K$, respectively. Here the intensity which has been used to remotely detect ground-ozone concentration from infrared satellite measurement is defined as the difference in brightness temperature between $11{\mu} m\;and\;9.7{\mu}m (i.e.,\; T_{11-9.7})$. The methods in this study have been applied to estimate ground-ozone from MODIS data in cases that there are significant correlations between the band intensity and ground-ozone. The values of estimated ozone significantly correlate (0.49-0.63) with ground observations at a significance level of $1\%$. For the improved methods, further study may be required to use tropospheric ozone rather than ground-ozone, considering the variation stratospheric ozone.

Analysis of the Practical Reasoning Process Presented in Home Economics Textbooks of 2007 Revised Curriculum (2007년 개정 교육과정에 기초한 7학년 가정 교과서에 반영된 실천적 추론 과정의 분석)

  • Lee, Min-Jung;Yoo, Tae-Myung
    • Journal of Korean Home Economics Education Association
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    • v.22 no.4
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    • pp.109-138
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    • 2010
  • This study examined how practical reasoning process is reflected in the 2007 revised home economics textbook of the 7th grade that is being used in schools since 2010. For a textbook analysis of the components of practical reasoning process, 12 published textbooks were all analyzed, and analysis areas were decided by reconstructing the textbook system into introduction, body contents, learning activities, evaluation. Analysis criteria were extracted from the previous literatures. Practical reasoning process was classified into Valued Ends, Context and Background, Alternatives and Means, on sequence, and Action and Reflection. As a result of analyzing categories and problems that practical reasoning process is reflected in the textbook, firstly, here was a category, which Valued Ends was absent in the practical reasoning process. In the relevant category, general problem solving progress and practical reasoning process could not be differentiated, and activity was developed with 'strategies for solution' as objective. Second, there was a category that the practical reasoning process was reflected in body contents. In this category, knowledge, concept, principle, and theory were insufficiently dealt with. Third, there was a category that reflected components of practical reasoning process but was covered with general problem solving process. Fourth, there was a category that described theme of sub-unit and body contents from the different curriculum perspectives. A curriculum perspective works as the foundation of preparing class contents or consistency of methods when developing lessons. Therefore, confusion might occur when a teacher plans a class with this kind of textbook. Fifth, a category that suggested partial components of practical reasoning process was shown the most and this category is difficult to maximize effects of practical reasoning process.

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The Learning Experience of 7th Graders on NOS (Nature of Science) as a Process in Research-Based "Becoming a Scientist" Mentor-mentee Program (중학생의 "과학자 되어보기" 멘토-멘티 프로그램 참여를 통한 과정으로서 과학의 본성 학습 경험)

  • Jung, Chan-Mi;Shin, Dong-Hee
    • Journal of The Korean Association For Science Education
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    • v.35 no.4
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    • pp.629-648
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    • 2015
  • This study is a case study examining how research-based 'authentic' science education program contextually facilitates students' learning on NOS as a process. We developed 'Becoming a Scientist' mentor-mentee program and applied it to six Korean 7th graders for 8 months. A mentor, who is also a researcher, provided scaffolding and coaching, and her mentees were to perform the whole process of science research, including selecting the research subject and questions, planning research design, doing experiments, collecting and analysing data, writing research paper, and experiencing poster presentation at an academic conference. The research questions are 1) What would the students experience at every step of their research process?, and 2) Which perceptions would they construct NOS as a process? Data include classroom observations, interview, mentor's journal, and students' learning products. The results show that the mentees have experienced their views of NOS as a process in various ways such as role of research question and purpose, validity of measured value, researcher's subjectivity in interpreting data, experience of making public and peer review, and significance of academic conference. This study has shown that students' actual experience in scientific research enhanced their views about NOS as process without explicit and reflective approaches. We defined 'authenticity' associated with not only with its similarity to what scientists do but to learner's identity as scientific researcher. Based on the situated learning theory, this study sheds light on the necessity of reconsideration about the meaning of authenticity and embodying authentic context in science education for better NOS learning.

Study on the Developmental Standard of Short Sensory Profile: Application to Korean Children Aged Seven to Nine Years Old (7~9세 아동의 단축감각력 발달적 기준에 관한 일연구)

  • Kim, Mi-Sun;Ji, Seok-Yeon;Keum, Hyo-Jin;Kim, Sung-Hee
    • The Journal of Korean Academy of Sensory Integration
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    • v.7 no.1
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    • pp.37-46
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    • 2009
  • Background : Theory of Sensory Integration (SI) was initially developed with an effort to understand children's behavior by Jean Ayres and has been evolved with extensive research by occupational therapist practitioners and researchers since in the latter of the 20 century. With extension of recognition to SI, various professions begin to refer their clients who are children with sensory integration dysfunction. Upon those referrals, occupational therapists normally use Short Sensory Profile (SSP) to screen and decide whether SI therapeutic intervention is needed or not. Objective : Purpose of this study is (1) to examine any difference between different age groups and genders for children who are seven to nine years old; (2) to compare the score results of those Korean children with the original Standard which is established for American children: and (3) to compare tendency of response for each item between children with- and without SI dysfunction. This study was intended to validate test items of the SSP and determine whether the original standard of SSP is applicable for Korean children. Method : 155 students (81 for male, 74 for female) underwent SI evaluation using the Korean-translated SSP. 52 student (22 for male, 30 for female) were 7 years old, 54 students (32 for male, 22 for female) were 8 years old, 49 students (27for male, 22 for female) were 9 years old. Results : There is no significant difference of SSP score by neither age nor gender. In comparison the average score and sensory integrative disorder with the American Standard, there is significant difference on score of sub-item and total score. For six items, there is no significant difference on the tendency of response between children with- and without SI dysfunction. Conclusions : It is concluded that the original standard is suitable for Korean children aged seven to nine. The six test items that children without SI dysfunction shown similar tendency to respond are questionable to be appropriate as screening test item. It is suggested to proceed to do further item analysis study and extend the study to broad age groups, so develop the most appropriate Standard of SSP for Korean children.

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Food Safety and Nutrition Education Program for Elderly and Assessment of Program Effectiveness Based on Health Belief Model (건강신념모델에 근거한 노인 대상 식품안전·영양교육 프로그램 효과 평가)

  • Choi, Jung-Hwa;Lee, Eun-Sil;Lee, Yoon-Jin;Lee, Hye-Sang;Chang, Hye-Ja;Lee, Kyung-Eun;Yi, Na-Young;Ahn, Yoon;Kwak, Tong-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.9
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    • pp.1366-1374
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    • 2016
  • Most elderly have difficulties in managing food safety and nutrition by themselves. Various nutrition educations for the elderly have been developed, but food safety and nutrition education program and educational tools for the elderly are very limited. The aim of the study was to evaluate a food safety and nutrition education program based on the Health Belief Model (HBM) for the elderly. Education program was implemented for 220 seniors (137 educated group and 83 control group) aged over 65 years at senior welfare community centers. The intervention study was carried out on a weekly basis during each of 5 weeks, and each session lasted about 35 or 40 minutes. The effectiveness of the program was assessed with a questionnaire before and after education. Education program consisted of a 5 week program, and topics were 'Dietary changes for the elderly's healthy life', 'Prevention of food poisoning in everyday life', 'Safe food handling for my health', 'Healthy dietary life to prevent chronic disease', and 'Safety! nutrition! healthy dietary life'. Education program materials such as slides, handouts, videos, leaflet, and booklets were developed. As a result, there were score improvements in knowledge, dietary behaviors, and health belief after intervention in the intervention group, which were higher than those of the control group. In particular, there was a meaningful interrelation between dietary behavior and health belief (r=0.520, P<0.001). This finding suggests that changing beliefs is very important to make desirable dietary behavioral changes. For this reason, we can conclude HBM theory is an effective model to educate nutrition and food safety for the elderly. Furthermore, food safety and nutrition education programs are implemented and delivered continuously at various settings such as a health center or community welfare center, and those will contribute significantly to enhance perception and change their desirable dietary behaviors for the elderly.