• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
• /
• pp.241-242
• /
• 2008

The Velocity Autocorrelation Function (VAF) of the sodium ions is calculated for a range of temperature from 250K to 1000K and converted into the linear ac-conductivity and ac-susceptibility response via Fourier transformation. A peak is found in the conductivity around $6\times10^{12}$ Hz that has some of the character of a Poley absorption. Here it is shown to be due to an harmonically coupled site vibrations of the sodium atoms, which extend only over a limited range. At frequencies below the peak the conductivity tends towards a constant i.e. dc value corresponding to a constant flow of ions through the simulation cell. At high temperatures the conductivity due to this ion transport process behaves like a metal with an insulator to metal transition occurring around a specific temperature.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.2299-2300
• /
• 2008

The Velocity Autocorrelation Function (VAF) of the sodium ions is calculated for a range of temperature from 250K to 1000K and converted into the linear ac-conductivity and ac-susceptibility response via Fourier transformation. A peak is found in the conductivity around $6{\times}10^{12}$ Hz that has some of the character of a Poley absorption. Here it is shown to be due to an harmonically coupled site vibrations of the sodium atoms, which extend only over a limited range. At frequencies below the peak the conductivity tends towards a constant i.e. dc value corresponding to a constant flow of ions through the simulation cell. At high temperatures the conductivity due to this ion transport process behaves like a metal with an insulator to metal transition occurring around a specific temperature.

• 조명전기설비학회논문지
• /
• 제20권10호
• /
• pp.27-34
• /
• 2006

본 논문은 드라이브의 간적벡터제어에서 ANN을 이용하여 유도전동기의 회전자 저항을 온라인 추정하기 위한 새로운 기법을 제시한다. 약전파 알고리즘은 신경회로망의 학습을 위해 사용된다. 신경회로망의 실제 상태값과 유도전동기의 요구값 사이의 오차는 신경회로망 모델의 하중값 조절을 위하여 역전파 하여 실제값이 요구값을 추정하도록 한다. 드라이브의 회전자 저항, 토크, 자속응답 성능등 이러한 추정기의 성능은 고유값으로부터 회전자 저항을 연구하게 된다. 회전자 저항은 유도전동기 드라이브의 벡터제어에서 제시된 ANN을 사용하여 추정한다.

• 한국전자파학회논문지
• /
• 제25권1호
• /
• pp.108-113
• /
• 2014

본 논문에서는 Q-band용 도파관의 내부 돌기가 전송 특성에 미치는 영향을 검토하였다. 도파관 내부의 그린함수를 고유 모드 함수 전개법으로 구하고, 돌기가 내장된 도파관의 내부 임피던스로부터 반사계수 표현식을 도출하였으며, 도파관 내의 내부 돌기가 반사계수에 미치는 영향을 검토하였다. 이론 해석의 타당성을 검증하기 위해 반사계수를 측정하고 이론치와 비교하였다.

• PNF and Movement
• /
• 제14권1호
• /
• pp.59-65
• /
• 2016

Purpose: The purpose of this study was to review articles in order to establish optimal contraction intensity and duration in the performance of relaxation techniques for maximal increase in range of motion. Methods: The Cochrane, EBSCO, Embase, Medline, ProQuest, PubMed, ScienceDirect, and Scopus databases were used to search articles from 1990 to January 2016. The search terms were "contract relax," "hold relax," "muscle energy technique (MET)," and "proprioceptive neuromuscular facilitation (PNF) stretching." Only experimental human studies (randomized controlled trials) that compared the effects of varying intensity and duration of isometric contraction were included. Non-English language and unpublished studies were excluded. Results: A total of 2,156 articles were initially identified, with only five eventually meeting the inclusion and exclusion criteria. Three studies compared the effects of varying intensity in isometric contraction and two studies compared the effects of varying duration in isometric contraction with regard to range of motion (ROM). Two articles suggested that submaximal voluntary isometric contraction was more effective than maximum voluntary isometric contraction (MVIC) in the improvement of ROM. One article showed that a longer contraction time led to greater increases in ROM. Conclusion: Submaximal voluntary isometric contraction was recommended during contract-relax exercises in healthy people. Lack of evidence makes it difficult to suggest the optimal duration of isometric contraction during relaxation techniques. For future research, high-quality evidence will be needed to establish the optimal contraction intensity for maximum improvement of ROM.

• 한국건축시공학회지
• /
• 제7권3호
• /
• pp.75-82
• /
• 2007

A vibration in the building occurs by influences of the facility equipment and the structural system. As the building recently becomes higher and bigger, the vibration in the floor slab is issued. Specially, the vibration with $4{\sim}8Hz$ frequency is harder to control than any other range of frequency. This vibration easily affects human sensibility and often makes the resonance phenomenon by corresponding with the floor slab's natural frequency when people and heavy equipments move. Moreover, the permission regulations for the vibration of the building are established by building's purposes. However, it is not subdivided in detail and sometimes ambiguous to each client. Even though the vibration could cause negative influences in a research building, there is not the vibration criterion for a research building. Therefore, it is necessary to set up its own vibration criterion with the client before building and to keep checking this vibration criterion under the construction. This study proposes the reasonable control methods and the vibration criterion for floor slab's vibration which are adapted to the R4-project. The R4-project is a research building and a high-rise building also. Accordingly, this study could help to the next similar project in the design and the construction phase.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2003년도 춘계 학술발표대회
• /
• pp.74-78
• /
• 2003

작물은 환경의 영향, 특히 기상조건과는 밀접한 관계가 있으며, 많은 학자들이 기상과 작물의 생육에 대한 연구결과를 보고하였다. (Kwon 등, 1989, 1993, 1994, cho등, 1979, 1984, Lee,등, 1982, Park등, 1975 ; Won등, 1983). 본 실험에서는 여수 지역의 고추수량과 기상과의 관계에 대한 기초 자료뿐만 아니라 1991년부터 2000년 까지의 기상 환경과 고추의 수량관계를 분석한 결과는 다음과 같다. 1. 월별 기상요인중 5월의 평균기온이 25.0%로 가장 높았고, 최고기온이 7.1%, 최저기온이 8.8%로 각각 높았으며, 8월의 평균기온이 6.6%, 최고기온이 6,2%, 최저기온이 6,9%로 각각 비교적으로 낮아서 변이가 적었다. 2. 생육 및 수량형질의 변이 계수에서 수량은 13.57%로 매우 높아 품종고유의 유전특성의 지배를 적게 받는 반면, 경장은 9.55%로 높아서 어느정도 환경요인에 영향을 받는 것으로 나타났다. 3. 기상요인과 수량 및 수량구성형질 간에서는 5월의 최고기온과 초장, 과장, 과경, 수량간에는 정의상관으로 유의성이 높았으며, 고추의 개화수정기간인 8월의 강수량과 초장, 과장, 수량간에는 부의 상관으로 유의성이 나타나 초기생육기인 5월의 높은기온과 개화기간인 8월의 적은 강수량이 높은 수량을 올릴수 있었다. 4. 수량과 수량형질 간에는 모두 정의상관으로 높게 유의성을 나타내었었다.

• 한국전자파학회논문지
• /
• 제24권7호
• /
• pp.722-729
• /
• 2013

본 논문에서는 밀리미터파 대역에서 저손실 전송 선로로 많이 사용되고 있는 구형 도파관의 단면 치수 변화가 전송 특성에 미치는 영향을 검토하였다. 도파관 내부의 그린 함수를 고유 모드 함수 전개법으로 구하고, 도파관 내부에 포스트를 설치한 구조의 내부 임피던스로부터 반사 계수 표현식을 도출하였으며, 도파관의 단면 치수 변화가 반사 계수에 미치는 영향을 검토하였다. 이론 해석의 타당성을 검증하기 위해 반사 계수를 측정하고, 이론치와 비교하였다.

• PNF and Movement
• /
• 제11권2호
• /
• pp.21-29
• /
• 2013

Purpose : The study was to evaluate the weight distribution, balance and gait function of stroke patients wearing lateral wedged insole to the shoe of the affected side. Methods : 27 patients with stroke (15 men, 12 women) participated in this study. Participants performed weight distribution, dynamic balance and gait ability with or without wedged insole on affected side in a random order. The balancia was used to evaluate the weight distribution. Deviation from the center line was analyzed by Dartfish during sit to stand to evaluate dynamic balance. The functional walk ability evaluated by 10 m walking velocity. Results : The asymmetry index of weight bearing improved significantly with wedged insole of affected side(p<.05). During sit to stand, center of gravity significantly moved from non-affected side to more mid line of body(p<.05). Improvement were shown in walking speed after wearing the wedged insole(p<.05). Conclusion : Wedged insole applied on affected side have a beneficial effect on weight distribution, dynamic balance and walking speed with stroke.

• PNF and Movement
• /
• 제9권4호
• /
• pp.23-31
• /
• 2011

Purpose : The aim of this study was to investigate the correlations between body compositions and bone mineral density in young women and postmenopausal women with low bone mineral density. Methods : Eleven young women (age, $25.85{\pm}1.96yrs$; height, $160.28{\pm}2.16cm$; weight, $56.89{\pm}9.66kg$) and ten postmenopausal women (age, $25.85{\pm}1.96yrs$; height, $160.28{\pm}2.16cm$; weight, $56.89{\pm}9.66kg$) with low bone density on femur neck were participated in this study. All subjects performed the measure of body composition and BMD on lumbar body and femur neck. Results : The results were as follows. Percent body fat, waist-hip ratio and body mass index(BMI) were significantly increased in postmenopausal women. BMD in lumbar body and femur neck were significantly decreased in postmenopausal women. There were negative strong correlation between BMD of the femur and age in young women. There were negative strong correlation between BMD of the femur and age or the years of menopause in postmenopausal women. There were positive strong correlation between BMD of the femur and BMD of lumbar body. Conclusion : Percent body fat and BMI were more increased in young women than in postmenopausal women. And there were negative strong correlation between BMD and age or the years of menopause in postmenopausal women.