• Title/Summary/Keyword: high frequency material characteristics

Search Result 411, Processing Time 0.029 seconds

Changes in the Usage of Dental Technology CAD/CAM (치과기공 CAD/CAM 사용에 대한 실태변화)

  • Nah, Jung-Sook
    • Journal of Technologic Dentistry
    • /
    • v.37 no.4
    • /
    • pp.271-284
    • /
    • 2015
  • Purpose: The purpose of this study was to examine the usage of CAD/CAM, which is one of dental technologist duties, in an effort to look for any possible changes in the usage of CAD/CAM. It's specifically meant to compare the results of this study with those of Lee Jong-do, Park Kwang-Sig(2011)'s study in March, 2011, to determine if there were any changes over the past four years. The selected variables that were investigated were the ownership of CAD/CAM, awareness of it, the route of acquiring the first information on it, the merits and demerits of its usage, usage experience and educational experience about it. Methods: An online survey was conducted on the dental technologists who worked in urban communities including metropolitan cities to find out the usage of CAD/CAM in 2015 from July 15 to 31, 2015, after existing questionnaire items were modified. The collected data were analyzed by IBM SPSS statistics 22.0, and statistical data on frequency, percentage, mean and standard deviation for each item were obtained. To figure out the characteristics of the subjects and the relationship between their occupational characteristics and the usage of CAD/CAM, crosstabs, independent-samples t-test and one-way ANOVA were utilized. As for the usage of CAD/CAM in 2011, the results of Lee Jong-do, Park Kwang-Sig(2011)'s study were selected, and then a comparative analysis was made. The level of significance was all set at .05. Total 250 questionnaires were distributed to them, and 190(76.0%) were returned. After excluding 23 whose answers were uncertain or seemed to lack reliability, total 167(66.8%) were used in final analysis. Results: As a result of analyzing the usage of CAD/CAM that was one of dental technologist duties, there was a great increase in the ownership of CAD/CAM in their workplaces from 2.4 percent in 2011 to 71.7 percent in 2015, and there was an improvement in awareness about it and the necessity of its usage as well. In 2011, the Internet and mass media were the most common route that they got to know about it. They had a strong tendency to acquire related knowledge through education in 2015, and there were some changes in the products that they used or preferred. In both years, the great merit of CAD/CAM was the simplified manufacturing process of restoration, and it had another great advantages in 2015 such as the improved quality of restoration or improved environments for dental technology. Concerning disadvantages, high price was a big problem in 2011. In 2015, not only price but the burden of material costs, frequent breakdown, poor demand among dental clinics and a lack of CAD/CAM professionals were pointed out a lot. In the future, this researcher intends to make research to seek ways of improving CAD/CAM professionals. Conclusion: There was more awareness of CAD/CAM in 2015 than in 2011 when the changes in awareness of it were analyzed, and the finding suggest the necessity of sustained education and concern.

Usage Status and Environmental Sustainability Guidelines for Building Exterior Materials (건축물 외장재의 사용 현황과 친환경 성능)

  • Park, Jong-Soo;Ko, Hune-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.9
    • /
    • pp.5861-5869
    • /
    • 2014
  • Existing studies of building exterior materials have focused on the colors or textures of cladding, and in terms of a design planning approach, have focused on the use of the environment and equipment and fire safety topics from an engineering perspective. As a result, little research has been done on performance guidelines for exterior materials, specifically according to the building type. Research into eco-friendly cladding materials is also in the rudimentary stage in a practical sense. In this study, the use of exterior materials over the last ten years in domestic construction was analyzed. The usage status of building exterior materials was evaluated quantitatively by frequency analysis, and its environmental performance is proposed through complex (qualitative + quantitative) analysis. The average value of the exterior material type number used for all analyzed buildings was 2.59. Glass, metal, stone, resin, cement, wood, and clay were used in that order with regard to the usage status. The analysis found that five of the materials satisfied the high efficiency and eco-friendly grading in terms of the four characteristics of an eco-friendly exterior. A list of eight eco-friendly elements was also proposed. The eco-friendly elements and characteristics of the exterior materials were derived to provide basic guidelines for domestic construction companies and design offices.

A Study on Classic Fashion Image and Sensible Vocabularies - Focusing on Women of Baby Boom and Y Generations - (클래식 패션 이미지와 감성 어휘 연구 - 베이비붐, Y세대 여성을 중심으로 -)

  • Sang, Yoon-Jin;Yoo, Jung-Min;Park, Minjung;Lee, Inseong
    • Journal of the Korea Fashion and Costume Design Association
    • /
    • v.17 no.3
    • /
    • pp.85-98
    • /
    • 2015
  • Modern fashion shows the trend of various styles and the period focusing on only product functions is changed to the period focusing on consumer's sensibility. Consumers show different sensitivities and preference by individual at the stage cognizing and recognizing the stimulation of given image and the method of objective measurement based on the fashion sensible vocabularies is necessary to measure fashion sensibility. Therefore, this research is significant to examine differences of preference to classic fashion by generation and awareness for sensible vocabularies and suggest methodology of design sensible evaluation research through the quantitative evaluation objectifying subjective sensibility. For the method of research, precedent theses related to classic, concept and characteristics of classic in books and definition and characteristics by generation were examined, the best 3 domestic portal sites were selected and adjective vocabularies and images related to classic were collected from 2010 to 2014. Among the 206 adjectives collected, vocabularies whose average is more than 3.5 were drawn by 5-point Likert scale for fashion expert group. And, among the total 306 images collected, 21 representative images were selected by preliminary investigation of fashion expert group. For the classic images and vocabularies selected, frequency analysis, factor analysis and variance analysis were conducted by SPSS 19.0. The results of analysis are as follows. Preference to classic fashion image by generation was analyzed. As a result, both of two generations selected classic fashion as the most classic one. The images of the next orders were analyzed. As a result, Y generation selected basic classic fashion image which is casual with high activity as a classic one. Baby boom generation selected ancient classic fashion image, so there were differences in preference for classic by generation. As a factor analysis on classic adjective vocabularies, they could be divided into 5 factors such as basic form, attractive form, traditional form, vintage form and active form and they verified that credibility of all measuring variables for classic sensible vocabularies was achieved. Differences of classic sensible vocabularies by classic fashion image and generation were examined. As a result, generation and classic fashion image made a significant effect on five factors. Therefore, there were differences of the awareness on classic fashion images and sensible vocabularies among the generations and this thesis can be a fundamental material which objectifies subjective sensibility and suggests the methodology of new research.

  • PDF

An Analysis of the Questions Presented in Chapters of Pattern Area in Elementary School Mathematics (초등수학의 규칙성 영역 단원에 제시된 발문의 특성 분석)

  • Do, Joowon
    • Education of Primary School Mathematics
    • /
    • v.24 no.4
    • /
    • pp.189-202
    • /
    • 2021
  • The teacher's questions presented in the problem-solving situation stimulate students' mathematical thinking and lead them to find a solution to the given problem situation. In this research, the types and functions of questions presented in chapters of Pattern area of the 2015 revised elementary school mathematics textbooks were compared and analyzed by grade cluster. Through this, it was attempted to obtain implications for teaching and learning in identifying the characteristics of questions and effectively using the questions when teaching Pattern area. As a result of this research, as grade clsuter increased, the number of questions per lesson presented in Pattern area increased. Frequency of the types of questions in textbooks was found to be high in the order of reasoning questions, factual questions, and open questions in common by grade cluster. In chapters of Pattern area, relatively many questions were presented that serve as functions to help guess, invent, and solve problems or to help mathematical reasoning in the process of finding rules. It can be inferred that these types of questions and their functions are related to the learning content by grade cluster and characteristics of grade cluster. Therefore, the results of this research can contribute to providing a reference material for devising questions when teaching Pattern area and further to the development of teaching and learning in Pattern area.

Comparison of the Recent Trend of Chemistry Education Research Based on the Analysis of the Domestic and Foreign Journals (국내외 학술지를 토대로 분석한 화학교육 연구의 최근 동향 비교)

  • Han, Jae-Young;Lee, Sang-Chul
    • Journal of the Korean Chemical Society
    • /
    • v.56 no.2
    • /
    • pp.290-296
    • /
    • 2012
  • This study analyzed the research papers published in three (2 domestic and 1 foreign) journals, in order to understand the recent trend of chemistry education research. We selected Journal of the Korean Chemical Society (JKCS) and Journal of the Korean Association for Science Education (JKASE) as the domestic journals, and Journal of Chemical Education (JCE) as a foreign journal. The papers published from 2000 to 2009 were analyzed. As the result, the chemistry education research theme focused on 'teaching method and education technology', 'learner's characteristics', and 'chemical concept and experiment' in the order of frequency. The research on 'curriculum and textbooks' was performed often in JKCS reflecting Korean social environment. The most researched chemistry education goal was the 'conceptual understanding/change' followed by 'achievement/grade' in JCE and 'experiment/inquiry skill' in JKCS, and 'attitude/interest/motivation' in JKASE. The research subjects were focused to 'middle or high school students' in JKCS, in contrast to the 'university students' in JCE. More concern to the higher education is required in the domestic research. The most frequently used research method was 'survey/ examination' followed by 'experimental research' in JCE and JKASE and 'data/material analysis' in JKCS. We discussed the implication on future chemistry education research.

Stress of the Pediatric Patient′s Parent in the Emergency Department (응급의료센터에 내원한 환아부모의 스트레스)

  • Park In-Sook;Lee Nam-Hyeong
    • Child Health Nursing Research
    • /
    • v.8 no.3
    • /
    • pp.260-271
    • /
    • 2002
  • This study was performed to identify the level of stress recognized by the parents as a support system for their infant patients who were hospitalized in an emergency department, thus to provide the resulting data as the basic material of care intervention for the families of infant patients. This study subjected the parents with infant patients who were hospitalized in emergency department of C University Hospital in Daejeon, and the data was collected from questionnaires for them, dating from Mar. 20, to Jun. 24, 2001 This study used the tool(30 questions) which was originally developed by Ji, Dong-ok (1992) for measuring the stress of families of infant patients in emergency room, and then was modified and complemented by this researcher suitably for infant patients. Collected data was statistically analyzed with frequency, percentage, mean, standard deviation, t-test, ANOVA, by using SPSS WIN10.0 program, and the results were as follows: 1. The stress of parents with infant patients hospitalized in emergency department averaged 3.31 on the basis of 5-point measure, which means that they felt stress beyond means. 2. The factor with high average out of stress factors the parents of infant patients recognized included the followings: 'about the pain of infant patients due to examination(3.91±1.00)'; 'about rare opportunity to be in contact with physician(3.78±1.09)'; 'delay in emergent treatment required for infant patients(3.75±1.31)'; 'delay in the general treatment of infant patients(3.72±1.32)'. Factors of the stress level includes the followings: 'care and medical treatment'(3.46±.72); 'body and diseases'(3.41±.97)'; 'lack of information and supportable resources (3.25±.77)'; and so on. 3. For the stress level according to general characteristics, there were statistically significant differences in the result of the condition of infant patients, medical treatment(P<.01), religion, the procedure of treatment(P<.05). With little preceding studies for infant patients hospitalized in emergency department, this study looked through the level of stress recognized by the parents of infant patients. Based on the comprehension on the parents with infant patients and the knowledge on stress factors recognized by the parents, it is expected that we can seek the methods of care intervention such as explanation of care and treatment procedures, unit policies, continuous interest and emotional supports as well as the provision of information to understand the responses of parents and reduce accompanied stresses.

  • PDF

Petrochemical Study on the Cretaceous Volcanic Rocks in Kyeongsang Basin, Korea: Possibility of Magma Heterogeneity (경상분지 백악기 화산암류에 대한 암석화학적 고찰: 이원성 마그마의 가능성)

  • Sung, Jong Gyu;Kim, Jin Seop;Lee, Joon Dong
    • Economic and Environmental Geology
    • /
    • v.31 no.3
    • /
    • pp.249-264
    • /
    • 1998
  • The Creataceous volcanic rocks distributed in the southeastern part (Kyeongsang basin) of Korea peninsula are composed of basalt, basaltic andesite, andesite, dacite and rhyolite. The variation of major elements show that contents of MgO, CaO, $FeO^T$, $Al_2O_3$, $TiO_2$ and $P_2O_5$ decrease with increasing of $SiO_2$, but $K_2O$ contents are increased slightly, $Na_2O$ widely dispersed. We can show slightly inflection point and low frequency of dacites in range between 63-65 wt.% $SiO_2$, while continuous trend exit in variation diagram. Variation trends in Harker diagrams for the major, minor, trace and REEs suggest that the BAV (basaltic to andesitic volcanics) and DRV (dacitic to rhyolitic volcanics) are not related to a simple crystal fractionation process. In the regime of under 65 wt. % in silica content, fractionation of olivine and clinopyroxene is predominant, while that of plagioclase happens strongly higher than 65 wt.% (e.g., $SiO_2$, vs. Eu and Sr, MgO vs. $Al_2O_3$ and CaO). The latter means low-pressure fractional crystallization for DRV. On the discriminant diagram, DRV are located in more mature environment than BAV. The $(Ce/Sm)_N$ vs. CeN digram shows that these two classes cannot be related to crystal fractionation. If they had been produced by fractionation, although they plotted in a slightly elongate cluster along the same horizontal trend, DRV should lie to the right of these primitive compositions. These diagrams clearly rule out a simple fractionation throughout from BAV to DRV. BAV had been influenced greatly subductiong slab as shown by K/Yb vs. Ta/Yb. We suggest that BAV primitive magma generated higher degree of partial melting than DRV primitive magma. LILE (K, Ba, $Rb{\pm}Th$) enriched characteristics as shown in BAV are inherited from subducting slab fluids and/or higher degree of partial melting of mantle material. However, lower degree of partial melting of mantle relative to BA V and contamination at high-level magma reservoir caused LILE enrichment to DRV.

  • PDF

A Study on Secondary School Girl Students' Life Style, Attitude toward Appearance and Clothing Attitude (중.고등학교 여학생의 라이프스타일, 외모에 대한 태도와 의복태도와의 관련 연구)

  • Lee, Eun-Hee
    • Journal of Korean Home Economics Education Association
    • /
    • v.18 no.4 s.42
    • /
    • pp.85-102
    • /
    • 2006
  • The objectives of this study were to classify of life style of secondary school girl students, to investigate the relationships between life styles, attitude toward appearance and clothing attitude. The method of this study was survey research by using questionnaires. Subjects were 658(middle school students 327, high school students 331) girl students located in Jeollabukdo province. In this statistical analysis, SPSS 11.5 for Windows program was utilized to calculate frequency, mean, cronbach's ${\alpha}$, factor analysis, t-test, Pearson's correlation, multiple regression analysis. The results of this research were as follows: The results of analysing the factors to the response lifestyles, attitude toward appearance and clothing attitude emerged five dimensions(digital orientation, material orientation, positive activity, achievement orientation, frugality), three dimensions(needs conformity value toward appearance), five dimensions(fashion pursuit, gender attractiveness, self-expression, aesthetic, and modesty). High school girls' students showed higher digital orientation and positive activity life styles, attitude toward appearance, clothing attitude except of modesty. Clothing attitude variables except of modesty had positive correlations with lifestyles and attitude toward appearance. However, modesty of clothing had negative correlations with life styles and attitude toward appearance. As a conclusion, secondary school girl students' life styles and attitude toward appearance constituted important characteristics which could affect clothing attitude directly.

  • PDF

Evaluation of Elution Characteristics by Material for Kitchen Utensils - Focusing on the Metallic Kitchen Utensils (유통 주방기구의 재질별 용출 특성 평가 -금속제 주방기구 중심으로-)

  • Kim, Jae-Kwan;Im, Kyung-Sook;Kim, Myung-Gil;Park, Sung-Hee;Seo, Mi-Young;Lee, Yu-Na;Kim, Jung-Sun;Ku, Eun-Jung;Chae, Sun-Young;Park, Yong-Bae;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
    • /
    • v.36 no.1
    • /
    • pp.51-59
    • /
    • 2021
  • In this study we analyzed the elution rates of 11 metals from 82 metallic kitchen utensils purchased in the market. The elution frequency of the 11 types of metals was iron > aluminum > chromium, nickel > zinc > copper > lead > arsenic > antimony > stannum > cadmium. For metallic kitchen utensils, the elution rate of heavy metals was 7.3-93.9%, and the average elution concentration was 0.001-13.473 mg/L. The average elution concentration of heavy metals was ranged between none-detected (N. D.) to 30.473 mg/L for non-coated kitchen utensils and 0.000-10.005 mg/L for coated kitchen utensils. The average elution concentration of metals from domestic kitchen utensils ranged from 0.001-25.145 mg/L, and from 0.000-33.518 mg/L for imported kitchen utensils. In particular, aluminum was found to be high in domestic kitchen utensils while iron was high in imported kitchen utensils. The average elution concentration of heavy metals was N.D.-2.670 mg/L for stainless steel, N.D.- 31.575 mg/L for aluminum, and N.D.-307.737 mg/L for iron. The amount of transition to food after cooking was investigated.

Landslide Susceptibility Mapping Using Deep Neural Network and Convolutional Neural Network (Deep Neural Network와 Convolutional Neural Network 모델을 이용한 산사태 취약성 매핑)

  • Gong, Sung-Hyun;Baek, Won-Kyung;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
    • /
    • v.38 no.6_2
    • /
    • pp.1723-1735
    • /
    • 2022
  • Landslides are one of the most prevalent natural disasters, threating both humans and property. Also landslides can cause damage at the national level, so effective prediction and prevention are essential. Research to produce a landslide susceptibility map with high accuracy is steadily being conducted, and various models have been applied to landslide susceptibility analysis. Pixel-based machine learning models such as frequency ratio models, logistic regression models, ensembles models, and Artificial Neural Networks have been mainly applied. Recent studies have shown that the kernel-based convolutional neural network (CNN) technique is effective and that the spatial characteristics of input data have a significant effect on the accuracy of landslide susceptibility mapping. For this reason, the purpose of this study is to analyze landslide vulnerability using a pixel-based deep neural network model and a patch-based convolutional neural network model. The research area was set up in Gangwon-do, including Inje, Gangneung, and Pyeongchang, where landslides occurred frequently and damaged. Landslide-related factors include slope, curvature, stream power index (SPI), topographic wetness index (TWI), topographic position index (TPI), timber diameter, timber age, lithology, land use, soil depth, soil parent material, lineament density, fault density, normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were used. Landslide-related factors were built into a spatial database through data preprocessing, and landslide susceptibility map was predicted using deep neural network (DNN) and CNN models. The model and landslide susceptibility map were verified through average precision (AP) and root mean square errors (RMSE), and as a result of the verification, the patch-based CNN model showed 3.4% improved performance compared to the pixel-based DNN model. The results of this study can be used to predict landslides and are expected to serve as a scientific basis for establishing land use policies and landslide management policies.