• 한국생활과학회지
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• 제16권4호
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• pp.877-884
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• 2007

Today the number of economically independent women are increasing in Korea, they have a tendency to pay more attention to their appearance in their social life. Female university students show a high tendency of that kind, especially when they prepare for their job interviews. They purchase beauty products, visit beauty salons and skin care centers to improve their looks. Above all, their interest in nail art is amazingly increasing for maintaining their self-image. This study thus aims at surveying the relationship between college woman's life style and their interest in nail care, by analysing life styles of college women pursuing up-to-date style. The results show that an 'egoistic' type has a high interest in and a high frequency of using a nail care center, and 'egoistic' type's demand for the nail service is equal to or quite higher than 'appearance-oriented' type's. That means that the 'egoistic' type seems to pay much attention to how they look, because they think their neat appearance help to accomplish their ego.

• 대한지역사회영양학회지
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• 제23권5호
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• pp.397-410
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• 2018

Objectives: An association between dietary patterns and mental health in children has been suggested in a series of studies, yet detailed analyses of dietary patterns and their effects on ADHD (attention deficit hyperactivity disorder) are limited. Methods: We included 4569 children who had dietary intake data as part of the CHEER (Children's Health and Environmental Research) study conducted nationwide from 2005 to 2010. We assessed ADHD (Attention Deficit Hyperactivity Disorder) by the DuPaul's ADHD Rating Scales and dietary intake by a semi-quantitative food frequency questionnaire. Using intake data, we constructed five dietary patterns: "Plant foods & fish," "Sweets," "Meat & fish," "Fruits & dairy products," and "Wheat based." Results: The overall proportion of ADHD was 12.3%. Boys (17.8%) showed a higher rate of ADHD than girls (6.5%). The total intake of calories (85 kcal) and plant fat (2g) in the ADHD group was significantly higher than that of the normal group. ADHD was significantly negatively associated with dietary habits such as having breakfast and meal frequency, and positively associated with eating speed, unbalanced diet, overeating, and rice consumption. Regarding dietary patterns, the "Sweets" category was relevant to high ADHD risk (OR 1.59, 95% CI: 1.18, 2.15 for Q5 vs. Q1) in a linear relationship. An inverse, non-linear association was found between "Fruits & dairy products" and ADHD (OR 0.55, 95% CI: 0.39, 0.76 for Q4 vs. Q1). Conclusions: Our study confirms both positive and negative associations between diet and ADHD in elementary school age children. Moreover, linear or nonlinear associations between diet and ADHD draw attention to the possible threshold role of nutrients. Further studies may consider characteristics of diet in more detail to develop better intervention or management in terms of diet and health.

• 한국재료학회지
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• 제24권2호
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• pp.67-72
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• 2014

Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties, including high strength, high hardness, excellent ductility and toughness. In this study, nanopowders of $Al_2O_3$, MgO and $TiO_2$ were prepared as starting materials by high energy ball milling for the simultaneous synthesis and sintering of the nanostructured compound $Mg_4Al_2Ti_9O_{25}$ by high-frequency induction heating process. The highly dense nanostructured $Mg_4Al_2Ti_9O_{25}$ compound was produced within one minute by the simultaneous application of 80MPa pressure and induced current. The sintering behavior, grain size and mechanical properties of the $Mg_4Al_2Ti_9O_{25}$ compound were evaluated.

• 정신신체의학
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• 제25권1호
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• pp.63-72
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• 2017

연구목적 본 연구는 주의력결핍 과잉행동장애(attention-deficit/hyperactivity disorder, ADHD) 환자들을 대상으로 다양한 실행기능과 정량화 뇌파간의 상관성을 알아보고자 하였다. 방법 31명의 소아청소년 ADHD 환자를 대상으로 정량화 뇌파를 측정하였다. 종합주의력검사(Comprehensive Attention Test, CAT), 스트룹 색-단어 추론 검사(Color-Word Inference Test, CWIT), 선추적 검사(Trail Making Test, TMT), 카드분류검사(Card Sorting Test, CST)가 시행되었고 한국어판 주의력결핍 과잉행동장애 평정척도(Korean version of the ADHD Rating Scale, K-ARS)가 측정되었다. 결과 CAT 검사 점수와 알파, 베타 파워가 양적 상관이 있는 반면, 델타 파워와는 부적 상관이 있었다. CWIT 검사에서는 감소된 델타 파워와 증가된 베타 파워가 높은 수행수준과 관련 있었다. 높은 TMT 검사 점수는 증가된 알파 대역 파워와 관련이 있었으며, CST 검사에서 델타 파워는 높은 수행수준과 부적 상관이 있는 반면 알파, 하이 감마파의 파워와는 양적 상관을 보였다. K-ARS 점수는 알파 파워와 부적 상관을 보였다. 결론 정량화 뇌파는 ADHD 환자들의 실행기능과 상관성을 보이며 신경생리학적 지표로서의 유용성이 시사된다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권3호
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• pp.103-107
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• 2004

Recently, greater attention has been paid to the high-speed generator for its many merits, such as ease of installation, high efficiency and high power density. However, due to their high fundamental frequency, careful consideration needs to be given to both electromagnetic and mechanical design issues. This paper deals with the comparison of two types of permanent magnet high-speed machines. Specifically, the effect of the permanent magnet magnetization pattern on the rotor losses is investigated. On the basis of analytical field analysis and the 2-D finite element method, this paper predicts the flux harmonics and rotor losses under the no-load condition. It is shown that the Halbach magnetization is superior to parallel magnetization in terms of producing rotor losses.

• 동아시아식생활학회지
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• 제17권5호
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• pp.615-625
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• 2007

This study investigated the overall conditions related to family meals, including perceptions, attitudes, and behaviors, among middle and high school students. The data were collected from 773 male and female students attending middle and high schools in Seoul and Kyunggi-Do from March to May 2006, using pre-tested self-administered questionnaires. The results are as follows: 78.9% of the subjects lived with their parents and siblings, and 75.7% regarded family meals as meals eaten with all family members living together in a household. As for the frequency of family meals, 40.1% of the middle school subjects answered that they ate with their family 'more than once per day' and 20.8% answered '1 or 2 time per a week'. However 21.0% of the high school students had family meals 'more than once per day', and 31.7% had family meals '1 or 2 times per a week', showing a significant difference between the groups(p<0.001). When the degree of satisfaction with life was evaluated using a Likert scale(strongly satisfied 5 point, strongly unsatisfied 1 point), the middle school students showed a significantly higher level of satisfaction than the high school students towards daily life, health, nutritive conditions, and family care. feelings, attitudes, and behaviors toward family meals were also evaluated(strongly agree 5 point, strongly disagree 1 point), and the results showed that the subjects had positive psychological feelings, with significant differences based on the frequency of family meals. Likewise, the groups who ate frequent family meals scored higher on aspects related to having positive attitudes and behaviors toward the family meal, implying that eating family meals is associated with promoting friendship, psychological stability, and positive thinking in adolescents. These findings suggest that attention needs to he directed toward increasing the frequency of family meals and creating a positive family meal environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1479-1481
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• 1996

The Purpose of this paper is to produce air core inductor and measure its electrical properties for high frequency. Especially we focused attention on the effect of geometrical parameters such as coil width, distance between coils, turn number. In addition, the influence of film morphology at inductor was investigated. Increase of coil width and decrease of turn number resulted in promotion of electric properties.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.7-13
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• 2020

We describes V2X technology, a connectivity-based recognition technology that is attracting attention as a key technology for implementing autonomous driving technology, and autonomous communication modules that implement ADAS technology, a sensor-based recognition technology. It also explains the trends in V2X technology standardization centered on IEEE 802.11p, which is a WAVE technology standard based on Wi-Fi/DSRC. Finally, we will discuss the market growth trend of V2X communication modules in the United States, the leading V2X technology module, and the development of technology development trends of major domestic and international companies that are leading the global technology market related to V2X communication modules. V2X and ADAS technologies will be the biggest influence on automotive purchasing decisions. In recent years, V2I mandates have been promoted beyond V2V, mainly in developed countries such as the United States. The related industry needs to focus on the development of information transmission network technology that can support high frequency high efficiency(transmission rate) and sophisticated positioning accuracy beyond conventional vehicle communication.

• 한국재료학회지
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• 제28권6호
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• pp.343-348
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• 2018

Recently, the properties of nanostructured materials as advanced engineering materials have received great attention. These properties include fracture toughness and a high degree of hardness. To hinder grain growth during sintering, it is necessary to fabricate nanostructured materials. In this respect, a high-frequency induction-heated sintering method has been presented as an effective technique for making nanostructured materials at a lower temperature in a very short heating period. Nanopowders of W and $Al_2O_3$ are synthesized from $WO_3$ and Al powders during high-energy ball milling. Highly dense nanostructured $W-Al_2O_3$ composites are made within three minutes by high-frequency induction-heated sintering method and materials are evaluated in terms of hardness, fracture toughness, and microstructure. The hardness and fracture toughness of the composite are $1364kg/mm^2$ and $7.1MPa{\cdot}m^{1/2}$, respectively. Fracture toughness of nanostructured $W-Al_2O_3$ is higher than that of monolithic $Al_2O_3$. The hardness of this composite is higher than that of monolithic W.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.1-6
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• 2001

In this article, the fundamental concept, characteristics and application potentials of coreless printed-circuit-board (PCB) transformers are described. Coreless PCB transformers do not have the limitations associated with magnetic cores, such as the frequency limitation, magnetic saturation and core losses. In addition, they eliminate the manual winding process and its associated problems, including labor cost, reliability problems and difficulties in ensuring transformer quality in the manufacturing process. The parameters of the printed windings can be precisely controlled in modern PCB technology. Because of the drastic reduction in the vertical dimension, coreless PCB transformers can achieve high power density and are suitable for applications in which stringent height requirements for the circuits have to be met. A transformer's power density of $24W/cm^2$ has been reported in a power conversion application. When used in an isolation amplifier application, coreless PCB transformers tested so far enable the amplifier to achieve a remarkable linear frequency range of 1MHz, which is almost eight times higher than the frequency range of 120kHz in existing Integrated-Circuit products. PCB materials offer extremely high isolation voltage, typically from 15kV to 40kV, which is higher than many other isolation means such as optocouplers. It is envisaged that coreless PCB transformers can replace traditional core-based transformers in some industrial applications. Their application potentials deserve more attention and exploration.