• Journal of Power Electronics
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• 제10권5호
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• pp.485-490
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• 2010

Sensorless control methods are generally used in motor control for home-appliances because of the material cost and manufactureing standard restrictions. The current model-based control algorithm is mainly used for PMSM sensorless control in the home-appliance industry. In this control method, the rotor position is estimated by using the d-axis and q-axis current errors between the real system and a motor model of the position estimator. As a result, the accuracy of the motor model parameters are critical in this control method. A mismatch of the PMSM parameters affects the speed and torque in low speed, steadystate responses. Rotor position errors are mainly caused by a mismatch of the stator resistance. In this paper, a stator resistance compensation algorithm is proposed to improve sensorless control performance. This algorithm is easy to implement and does not require a modification of the motor model or any special interruptions of the controller. The effectiveness of the proposed algorithm is verified through experimental results.

• 대한가정학회지
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• 제49권10호
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• pp.49-56
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• 2011

The purpose of this study is to research the difference between the size suggested by brand uniforms and the size suitable for high school girls. We compared and analyzed the size system of brand uniforms after researching the wearing conditions of uniforms of 4 brands (A, B, C, D) in order to establish a size system of brand uniforms that fits different body types of teenagers. First, we conduct research on the actual condition of brand uniforms worn by high school girls, and investigate unsatisfactory factors and problems. Second, we actually measure the uniform size of each brand and analyze measurement differences between each brand. Our results show each brand uniform has different size specifications and the importance of appropriate size specification is greater as students select uniform based on design and brand awareness rather than body size. Compared with the average body size the skirt and especially the blouse is much smaller with no extra room compared with standard size 85 blouses and size 71 skirts. Therefore, the adjustment of size specification is needed in brand school uniforms. However, a larger scale investigation is needed as this study was conducted with a limited sample size.

• 대한가정학회지
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• 제28권4호
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• pp.41-50
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• 1990

Soy protein was isolated from Korean soy bean 'Chang ryub' and chemically modified with succinic anhydride. Functionality of the soy protein isolate(SPI), succinylated SPI(SPPI), and PP590(commercial) at various pH were investigated. The mechanical and sensory properties of soy bean curds made from several mixing ratio of succinylated soy bean milk were observed. The solubility of SPI significantly increased with succinylation. The solubility of PP590 was lower than that of SSPI. The solubility of SPPI increased significantly in 0.03M CaCl2 solution. The emulsifying activity of SSPI increased. On the range of pH above pI the emulsifying activity of PP590 was higher than that of SPI. There was no difference in emulsion stability among the groups. The foam expansion capacity of SPPI increased at higher pH than pI but the foam stability decreased significantly above pH 9. Mechanical texture profile analysis revealed the modified soy bean curds had the lower hardniss, chewiness and cohesiveness with increased modification. The mechanical characteristics of modified soy bean curds revealed generalized Maxwell Model of 7-elements or 5-elements. In sensory evaluation, the hardness, the springiness and acceptability of modified soy bean curds were lower significantly than those of control soy bean curd.

• 대한가정학회지
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• 제36권10호
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• pp.35-48
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• 1998

The Korean family is changing. The growth in dual-earner households has been the 'revolution' of the century, implying inevitable modification of the role division in marriage toward greater symmetry of responsibility for breadwinning and homemaking. So, the purpose of this study is to understand husbands' housework and to investigate the change of the husbands' housework. This means to investigate how the husband is related to housework. For these research purpose, 60 dual-earner couples were deeply interviewed. The major discussions of this study can be summarized as follows: There are four types of housework in men's work, the type of refusal, the type of avoidance, the type of inevitability, and the type of participation. These types are taken order to understand change in housework is women's work. Men in the type of avoidance in household work is 25%, they have a tendency to avoid housework with making any excuses. People in the type of inevitability is 20%. These men are compelled to work in household owing to circumstances beyond control. 13% of couples is type of participation. These have a new idea of housework. They don't get the gender role division. They can become a good husband. and eventually solve conflicts and problems in couples.

• Current Optics and Photonics
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• 제1권2호
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• pp.90-94
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• 2017

Visible light identification (VLID) is a user identification system for a door lock application using smartphone that adopts visible light communication (VLC) technology with the objective of high security, small form factor, and cost effectiveness. The user is verified by the identification application program of a smartphone via fingerprint recognition or password entry. If the authentication succeeds, the corresponding encoded visible light signals are transmitted by a light emitting diode (LED) camera flash. Then, only a small size and low cost photodiode as an outdoor interface converts the light signal to the digital data along with a comparator, and runs the authentication process, and releases the lock. VLID can utilize powerful state-of-the-art hardware and software of smartphones. Furthermore, the door lock system is allowed to be easily upgraded with advanced technologies without its modification and replacement. It can be upgraded by just update the software of smartphone application or replacing the smartphone with the latest one. Additionally, wireless connection between a smartphone and a smart home hub is established automatically via Bluetooth for updating the password and controlling the home devices. In this paper, we demonstrate a prototype VLID door lock system that is built up with LEGO blocks, a photodiode, a comparator circuit, Bluetooth module, and FPGA board.

• 대한가정학회지
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• 제30권1호
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• pp.267-282
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• 1992

This study investigated (1) present modes of parent education in the kindergartens, (2) mother's level of and need for knowledge about child development, child rearing and related areas, and (3) the variables that related to mothers' needs in these areas. The subjects of this study were 80 teachers and 674 mothers of 21 kindergartens in Seoul. The instruments were two questionnaires on a 4-point scale. The questionnair for mothers was composed of 86 items, and that for teachers was of 14 items. The data were analyzed with frequency, percentage, mean, standard deviation and multiple regression. The results showed that (1) The most common type of parent education was techer-parent conference and newsletter. The contents and methods of parent education was mainly decided by the directors in consulation with teachers. (2) Among the six general areas, mothers had most knowledge abut modification of child behavior, but their most felt needs was knowledge about child development (3) Need assessment based on item analysis revealed, in descending order, felt needs for knowledge about creative development, observation techniques, social developement, saftey and first-aid, and ways to stimulate educational motivation. (4) The variables that predicted mothers' felt needs were the birth order of the child, mother's experience in parent education, family cohesion, adaptability and communication.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권1호
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• pp.13-20
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• 2022

Purpose: Hydrogen-methane breath tests are used to diagnose carbohydrate malabsorption and small intestinal bacterial overgrowth. The COVID-19 pandemic has driven the modification of procedures as breath tests are potentially aerosol-generating procedures. We assessed the effect of delayed analysis of breath samples, facilitating the at-home performance of breath testing. Methods: Children provided two breath samples at every step of the lactose breath test. The samples were brought back to the clinic, and one set of samples was analyzed immediately. The second set was stored at room temperature and analyzed 1-4 days later. Results: Out of the 73 "double" lactose breath tests performed at home, 33 (45.8%) were positive. The second samples were analyzed 20 to 117 hours after the first samples (41.7±24.3 hours). There was no significant difference in the hydrogen concentration between the first and second sets (Z=0.49, p=0.62). This was not the case for methane, which had a significantly higher concentration in the second breath samples (Z=7.6). Conclusion: Expired hydrogen levels remain stable in plastic syringes if preserved at room temperature for several days. On the other hand, the delayed analysis of methane appeared to be less reliable. Further research is needed to examine the impact of delayed analysis on methane and hydrogen concentrations.

• 한국수학교육학회지시리즈A:수학교육
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• 제50권3호
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• pp.285-308
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• 2011

The objective of this study is to review how researches on mathematics education are being conducted currently in Korea and overseas and to examine the current state of domestic researches on mathematics education from a broader view. Although many efforts have been made to understand trends in researches on mathematics education, there have been few in depth studies on research trends in overseas or for comparison between domestic and overseas trends. Thus, this study classified and analyzed 181 domestic articles between 2005 and 2009 in the journals and and 201 overseas articles in the journals and according to year, research area, research contents, school level, research method, and key words using the PME classification system with some modification. Through these analysis, we examined research trends on secondary mathematics education in Korea and overseas. The research findings are as follows. First, 'teaching learning process' was a spotlight area both at home and overseas, and 'realistic mathematics' and 'social cultural subjects' were not covered much either at home or overseas. 'Mathematical communication' occupied a very small portion in Korea but was a highly interesting area in overseas research. Second, research contents of interest were different between Korea and overseas. Research on general area was the mainstream. But geometry and statistics were mainly studied in Korea and algebra and analysis in overseas. Third, research related to middle school was twice more than that related to high school in Korea, But, research related to middle school was the same as high school in overseas. Fourth, qualitative research was the absolute majority both at home and overseas, and philosophical didactical analysis was used only in Korea. Fifth, the order of key words were problem solving - teacher - curriculum - creativity - textbook in Korea, but teacher - teaching - semiotic - affective factor - proo f- problem solving - technology in overseas.

• 대한가정학회지
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• 제37권3호
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• pp.175-191
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• 1999

The purpose of this study was to investigate the eating behavior and life habits of kindergarten children 5 to 7 years old in Chuncheon area. This study was conducted in December, 1996. Anthropometric indices(height, weight, skinfold thickness, mid-arm circumference) were measured and body mass index(BMI), Rohrer index, arm fat area were calculated to estimate children’s body fatness. Also the eating behavior and life habits were determined tv using questionnaire method. The results were as follows: Body fat rate of the children was almost normal according to Rohrer index and BMI. There was significant difference in birth weight between male and female. The problems of the eating behavior were frequent skipping breakfast and eating-out. The rate of the children who took snacks 2 times a day was 46.9％. Most children tended to take sweet snacks such as ice-cream, chocolates, cookies, and they tended to prefer meats and fishes to vegetables. The rate of breast feeding was 28.3％ and the rate of weaning foods prepared at home was 61.1%. Many children preferred indoor activities such as watching TV, toy furniture play, building block to outdoor activities such as roller-skating, cycling, jogging in their spare time. The rate of the children who took exercise regularly was 15％. Children tended to eat kimbap, fried chicken, ramyeon more frequently in various instant foods. The intake rates of fruit juice and barly tea were relatively high and children's favorite fruits were watermelon and mandarin orange. From this results, skipping breakfast, frequent eating-out and the monotony of food preference appears to cause imbalance in nutrient intakes of the children and to have bad influence on children’s health. Accodgingiy, the comprehensive nutrition education and proper modification program should be needed for the children and their parents to correct the eating behavior and life habits. The reasonable exercise programs are needed to motivate outdoor activities of the children, and the importance of breast feeding and weaning foods should be emphasized to lactating women and pregnant women.

• 대한지역사회영양학회지
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• 제23권4호
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• pp.318-332
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• 2018

본 연구에서는 12주 동안 성인 여성 중 체지방률 40% 이상 또는 BMI 30 이상인 여성을 대상으로 37차시의 비만관리 프로그램일환으로 영양교육과 운동중재를 병행 실시하여 대상자의 식습관 및 운동 습관 조사, 신체성분과 식이섭취와 생화학적 지표에 미치는 효과를 살펴보고자 하였다. 1. 조사대상자의 평균 연령은 44.8세였으며 참여자의 55%가 폐경이었다. 2. 체중조절 관심도 변화에서 체중 조절 방법은 식사조절과 운동이 프로그램 참여 전 34.4%에서 프로그램 후 37.5%로 증가하였다(p<0.01). 3. 신체활동 변화에서 중등도 신체활동을 10분 이상 한날은 프로그램 참여 전 3.20일에서 프로그램 후 4.25일로 증가하고, 스트레칭 등 유연성 운동을 한 날은 프로그램 참여 전 2.60일에서 프로그램 참여 후 3.85일로 유의적으로 증가하였다(p<0.01). 4. 바른 식습관 점수 변화는 프로그램 참여 전 4.15점에서 프로그램 참여 후 7.10점으로 유의적(p<0.001)으로 증가하였다. 5. 에너지 및 다량 영양소 섭취는 프로그램 전후간 차이는 없었으나 식이섬유(p<0.01), 철, 칼륨, 비타민A, 비타민 $B_6$, 나이아신의 섭취는 프로그램 참여 전에 비해 프로그램 참여 후에 유의적으로 증가하였다(p<0.05). 6. 혈압과 혈액 생화학적 특성 지표인 TC, 공복혈당 및 TG는 프로그램 참여 전후 간 유의적인 차이는 없었다. 7. 영양교육과 운동 프로그램 종료 후 체중, 체지방률, 복부둘레 및 내방지방 수치는 유의적으로 감소하였으며, 근육양과 신체발달 점수는 유의적으로 증가하였다(p<0.001). 이상의 결과를 볼 때, 중등도 비만여성에서 12주간 영양교육과 운동 중재 프로그램 실시는 식사의 질을 향상시키고 바림직한 식습관의 변화를 유도하였으며 비만도는 감소하면서 근육양이 증가하여 요요현상이 없이 비만관리 프로그램 교육 내용이 긍정적인 영향을 미쳤으며, 향후 장기적인 비만의 지속관리와 체계적인 연구가 계속되어야 할 것으로 사료된다.