• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.87-90
• /
• 2005

High-efficiency switched-mode circuits such as the class-E amplifier are well-known in the MHz frequency range. The class-E amplifier is a type of switching mode amplifier offering very high efficiency approaching 100%. In this paper of the class-E amplifier by using pHEMT device, the design has been done theoretically and experimentally, with simulation by using the harmonic balance method using circuit simulator. The amplifier using microstrip circuit and the pHEMT demonstrate 66% power-added- efficiency (PAE) at 2.4GHz with 17.6dBm of output power.

• Journal of Nutrition and Health
• /
• 제37권4호
• /
• pp.316-328
• /
• 2004

The objective of this study was to investigate the differences in food intake patterns by the economic status. Data from the 1998 Korean National Health and Nutrition Survey were used. Using the poverty line based on the 1998 Korean minimum cost of living, the subjects (n = 10400) were classified into high class (36.1%), middle class (40.7%) and low class (23.1%). Mean intakes for other food groups except grains, potatoes and vegetables became higher as the eco-nomic levels were going up. By the family size, it was found that intakes of grains and fishes were different (p<0.05). By the economic status, intakes of fruits (p<0.05), meats (p<0.05) and fishes (p<0.01) were different. There were no significant differences in consumed types of food by the economic status. Rice was the most prevalent food in all clas-ses and its intakes increased as the economic status was going down. In the dietary patterns of main food group (GMDVF: Grain, Meats, Dairy, Vegetable and Fruit), the pattern except dairy (11011) revealed the highest proportion in high-middle class while the patterns without dairy and fruit food groups (11010) had the highest proportion in low class. The propor-tions of subjects with the low dietary diversity score (DDS) increased as economic status was going down (p<0.01). The food groups that most people do not consume were the dairy and fruit group. Proportions of people who missed one or more group increased as economic status was going down. The high dietary variety score (DVS) also was linked to a high score on the DDS and high class (p＜0.01). Thus the intakes of the dairy and fruits product should be increased in all classes. The low class especially had worse quality of food intakes pattern than that of the high or middle class. The nutrition policy and education programs need to be established according to the economic status.

• 소음진동
• /
• 제9권6호
• /
• pp.1227-1233
• /
• 1999

Modern technology depends on the reliability of extremely high technology equipments. In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a nanometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. This paper deals with the structural dynamic design in high class semiconductor factory in order to be satisfied more strict vibration criteria for high sensitive equipment.

• 한국컴퓨터정보학회논문지
• /
• 제28권3호
• /
• pp.137-148
• /
• 2023

본 연구의 목적은 잠재프로파일분석(Latent Profile Analysis)을 적용하여 다문화청소년 어머니의 정신건강의 잠재유형을 분류하고 예측변인의 영향력을 분석한 후 잠재유형의 차이가 부모효능감에 어떠한 영향을 미치는가를 규명하기 위함이다. 이를 위해 다문화청소년 패널조사(MAPS) 9차년도(2019년) 패널데이터를 활용하였다. 분석결과, 첫째, 다문화청소년 어머니의 정신건강 유형은 '정신건강 중간 위험형'(class3) > '자아존중감 상위형'(class1) > '정신건강 고 위험형'(class4) > '문화적응과 일상생활 스트레스 상위형'(class2) 순으로 분석되었다. 둘째, '자아존중감 상위형'(class1) 집단과 비교해 다문화청소년 어머니의 가정경제 수준이 낮을수록, 다문화청소년 아버지(남편)의 학력이 중학교졸업 이하일수록, 한국어 수준이 낮을수록, 자녀와의 의사소통 정도가 낮을수록 '정신건강 중간 위험형'(class3) 집단에 속할 승산(Odds)은 높아지는 것으로 분석되었다. 셋째, '정신건강 중간 위험형'(class3) 집단과 '정신건강 고 위험형'(class4) 집단과 비교해 '자아존중감 상위형'(class1) 집단이 부모효능감에 유의미한 정(+)적인 영향을 미치는 것으로 확인되었다.

• 한국조리학회지
• /
• 제22권1호
• /
• pp.19-31
• /
• 2016

In this study, the SCAMPER method which is a creative thinking method is applied in the food and beverage class of a specialized high school NCS study module to enhance creative thinking and investigate the influence on learning motivation of students. For verification, 10 sessions of 50 minutes classes were performed on 1, 2 grade students in H high school located in Gyeonggi-do Yangju City from August to November 2015 subject to 54 subjects in the experiment group and 54 subject in the control group. To look into the influence of the NCS food and beverage practice class using the SCAMPER method on learning motivation, pre post survey investigation was conducted on the students for measurements through surveys to deduct conclusions. As a result, it was verified that the NCS food and beverage practice class using the SCAMPER method had positive influence on the learning motivation of specialized high school students and positive change was also found in the awareness of SCAMPER method using classes and creative activities in the students. In this study, the influence of the NCS food and beverage practice class using the SCAMPER method on learning motivation subject to specialized high school students is investigated to have meaning as data to expand the research range of NCS food and beverage practice education.

• 한국치위생학회지
• /
• 제21권6호
• /
• pp.813-820
• /
• 2021

Objectives: This study was conducted to verify the effectiveness of the VR-applied head and neck anatomy class and to be used as basic data for the development of a teaching method using VR in the basic dental hygiene field. Methods: A convenience sample was extracted from 128 students and graduates who completed the head and neck anatomy class at the department of dental hygiene at a university in Gwangju. From June 1 to July 31, 2021, an online survey was conducted on class attitude and satisfaction, and statistical analysis was performed using frequency analysis and independent sample t-test. Results: Class attitude (3.79), interest (3.64), attention (3.88), learning motivation (3.80), and achievement motivation (3.84) were all high in the head and neck anatomy VR application group (p<0.01). Satisfaction (3.99), relevance of class content (4.06) and class achievement (3.96) were high in the head and neck anatomy VR application group (p<0.01). The suitability of class attitude (3.65) and class content (sub-item of class satisfaction) (4.13) was high in the group with the 4th industrial revolution education experience (p<0.05). Conclusions: The effect of VR application in the head and neck anatomy class was confirmed to increase students' class attitude and satisfaction. In the basic dental hygiene curriculum, it will be necessary to develop and utilize teaching methods related to the 4th industrial revolution and VR application classes.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제44권3호
• /
• pp.435-456
• /
• 2005

This research aims to analyse implementation effects of the Real mathematics Education(RME) in the high school probability and statistics For this aim, two research questions are estabilished as fellows. (1) Is there any improvement of mathematical achievement in the class by RME's lecture than in the class by the mathematics text's lecture ? (2) Is there any improvement of mathematisation level in the class by RME's lecture than in the class by the mathematics text's lecture ? Before answering the above research questions, RME.`s lecture notes and ordinary lecture notes are developed based on the learning principles of the RME and mathematics textbook respectively. Two classes are randomly chosen from a high school located at midium size city and assigned as the experimental group and the control group respectively. The 20 hours of the RME's lecture notes is administerd to the experimental group and the 20 hours of the odinary lecture notes is administerd to the control group. It is shown that the class by RME's lecture is more effective in both of the mathematical achievement and the mathematisation activity than the class by the ordinary lecture. Hence, it is urged from the result of this research that RME's context will be developed and the RME's lecture will be implemented in the other field of high school mathematics.

• Computers and Concrete
• /
• 제8권5호
• /
• pp.583-595
• /
• 2011

This paper studied the cement efficiency factor (k factor) of high calcium Class F fly ash. This k factor represents a unit of fly ash with efficiency equivalent to k unit of cement. The high calcium Class F fly ash was used to replace cement in concrete. The modified Bolomey's law with linear relationship was used for the analysis of the result of compressive strength, cement to water ratio (c/w) and fly ash to water ratio (f/w) by using the multi-linear regression to determine the k factor and other constants in the equations. The results of analysis were compared with the results from other researcher and showed that the k factor of high calcium Class F fly ash depends on the fineness of fly ash, replacement level and curing age. While the amount of CaO content in Class F fly ash not evident. Furthermore, necessary criteria and variables for the determination of the k factor including the use of the k factor in concrete mix design containing fly ash were proposed.

• 한국멀티미디어학회논문지
• /
• 제25권6호
• /
• pp.886-893
• /
• 2022

Outlier detection refers to the task of detecting data that deviate significantly from the normal data distribution. Most outlier detection methods compute an outlier score which indicates the degree to which a data sample deviates from normal. However, setting a threshold for an outlier score to determine if a data sample is outlier or normal is not trivial. In this paper, we propose a binary prediction method for outlier detection based on spectral clustering and one-class SVM ensemble. Given training data consisting of normal data samples, a clustering method is performed to find clusters in the training data, and the ensemble of one-class SVM models trained on each cluster finds the boundaries of the normal data. We show how to obtain a threshold for transforming outlier scores computed from the ensemble of one-class SVM models into binary predictive values. Experimental results with high dimensional text data show that the proposed method can be effectively applied to high dimensional data, especially when the normal training data consists of different shapes and densities of clusters.

• 조명전기설비학회논문지
• /
• 제25권11호
• /
• pp.98-102
• /
• 2011

This paper describes inverse E class frequency multiplier which is lower inductance and peak switching voltage than E class frequency multiplier. The frequency multiplier is designed to generate 5.8[GHz] frequency by doubling the input frequency 2.9[GHz]. The peak switching voltage of designed inverse E class frequency multiplier with 11[V] is lower 4[V] than that of E class frequency multiplier with 15[V]. The inverse E class frequency multiplier has a conversion gain 6[dB] at output power 21[dBm] and maximum 35[%] power efficiency.