• 대한전자공학회논문지TC
• /
• 제38권1호
• /
• pp.34-42
• /
• 2001

편파기 특성을 갖는 새로운 주파수 선택반사기의 새로운 주기적 배열 구조를 제시하였다. 배열 구조는 평면 유전체 슬랩의 양면에 도체 다이폴을 주기적으로 배열하고 윗면의 다이폴과 아래면의 다이폴은 서로 대략 $90^{\circ}$ 정도로 직교되며 유전체 두께는 유전율을 고려한 주파수 파장의 1/8정도이다. 산란 해석으로는 파수 영역 이미턴스방법과 모멘트 방법이 사용되었다. 제시한 새로운 주파수 선택반사기의 편파 변환 기능을 확인하기 위해 설계/제작하여 반사 손실과 투과 손실을 측정하였다. 측정 결과는 이론치와 매우 일치되었으며 반사시 선형 편파인 입사파가 원형 편파로 변환됨을 확인하였다.

• 충청수학회지
• /
• 제19권2호
• /
• pp.141-151
• /
• 2006

We investigate the multiplicity of $2{\pi}$-periodic solutions of the nonlinear Hamiltonian system with almost polynomial and exponential potentials, $\dot{z}=J(G^{\prime}(z)+h(t))$, where $z:R{\rightarrow}R^{2n}$, $\dot{z}=\frac{dz}{dt}$, $J=\(\array{0&-I\\I&o}\)$, I is the identity matrix on $R^n$, $H:R^{2n}{\rightarrow}R$, and $H_z$ is the gradient of H. We look for the weak solutions $z=(p,q){\in}E$ of the nonlinear Hamiltonian system.

• 폴리머
• /
• 제34권4호
• /
• pp.289-293
• /
• 2010

비스트리에톡시시릴에탄(bis(triethoxy silyl) ethane)을 전구체로 도데실 트리메틸암모늄 브로마이드(dodecyl trimethyl ammonium bromide), 세틸 트리메틸암모늄 브로마이드(cetyl trimethyl ammonium bromide), 그리고 옥타데실 트리메틸암모늄 브로마이드(octadecyl trimethyl ammonium bromide)를 구조유도체로 사용하여 주기적인 메조포러스 유기실리카(periodic mesoporous organosilicas)(PMO)를 합성하였다. 합성된 PMO의 경우 구조유도 체로서 사용한 계면활성제의 알킬기가 증가할수록 PMO의 표면적과 기공부피가 감소하였으나 기공의 직경에는 영향 이 없었다. 그리고 합성된 PMO에 폴리에틸렌을 삽입한 결과 사용한 구조유도체의 알킬기의 크기에 따라서 폴리에 틸렌의 삽입과정에 많은 영향이 있었으나, 폴리(에틸렌 옥사이드)의 경우 합성된 PMO의 특성에 영향이 거의 없음을 XRD와 DSC로 확인하였다. 또한, 고분자의 열안정성을 확인한 결과 PMO에 삽입된 고분자의 열분해 온도가 증가함 을 알 수 있었다.

• 충청수학회지
• /
• 제25권4호
• /
• pp.753-762
• /
• 2012

We study the BS-stability and the $\rho$-stability for functional difference equations with infinite delay as a discretization of Murakami and Yoshizawa's results [6] for functional differential equation with infinite delay.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
• /
• pp.699-706
• /
• 2001

Waterproofing materials should be expected to last the life of the structure. An approximate life cycle cost should be to compare different materials based on initial and periodic repair / maintenance costs. Waterproofing applicators like materials that are easy to set up and clean up. The designer should choose a material that can be applied in almost all conditions. Design Professionals should specify independent inspection on critical jobs or in all cases where the budget permits. The basic causes of defection occurred during construction should be minimized.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제3권2호
• /
• pp.123-129
• /
• 1996

In this paper, we investigate the properties of various limit sets. In particular, we study the relationship between the recurrent set and special $\gamma$-limit set. And also we show that if $\chi$ is not almost periodic, then $\chi$ is special a-limit.

• 충청수학회지
• /
• 제26권1호
• /
• pp.197-211
• /
• 2013

We study some stability properties in discrete Volterra equations by employing to change Yoshizawa's results in [13] for the nonlinear equations into results for the nonlinear discrete Volterra equations with unbounded delay.

• 대한간호학회지
• /
• 제23권2호
• /
• pp.207-223
• /
• 1993

Inpatients are mostly occupied in bed with restricted activity, nearly all patient populations are at risk for the occurrence of skeletal muscle atrophy due to decreased level of activity. Restriction of mobility is far greater in pediatric patients compared with adult patients since almost all the activities of daily living is performed by parents or caregivers. It could be assumed that pediatric patients are more vulnerable to skeletal muscle atrophy than adult patients, however, there have been no attempts to reduce the atrophy of developing muscle. Therefore it is important to determine the effect of exercise in developing muscle during decreased activity. The purpose of this study was to determine the effect of periodic weight support during hindlimb suspension on the mass and cross-sectional area of Type I and II fibers in developing soleus(Type I ) muscle. To examine the effectiveness of periodic weight support activity in maintaining mass and fiber size. the hindlimb of young female Wistar rats was suspended(HS) and half of these rats walked on a treadmill for 45min / day(15min every 4h) at 5m / min at a 15 grade(HS-WS). After 7days of hindlimb suspension, soleus wet weight was 28. 57% smaller and relative soleus weight was 28. 21% smaller in comparison with con-trol rats (p〈0.05) Soleus wet weight and relative soleus weight increased by 67.72% and 71.43% each with periodic weight support activity during hindlimb suspension (p〈0.01, p〈0.005), moreover soleus wet weight and relative soleus weight of the HS -WS rats were greater than those of the control group. No change was observed in fiber type percentage of the developing soleus muscle after 1 week of hindlimb suspension plus weight support activity. Type I and II fiber cross-sectional areas of the developing soleus muscle were 50.45% and 43.39% lower in the HS group than in the control group (p〈0.0001), type I and II fiber cross-sectional areas of the developing soleus were 24.49% and 29.93% greater in the HS - WS group than in the HS rats (p〈0.0001), whereas Type I and II fiber cross-sectional areas of HS - WS group were less than those of the control group, The results suggest that periodic weight support activity can ameliorate developing soleus muscle atrophy induced by hindlimb suspension, even in type II fibers that would not have been expected to be recruited by this type of neuromuscular demand. Clinical experimental study is needed to deter-mine the effect of periodic weight bearing exercise on developing atrophied leg muscle based on these results.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권3호
• /
• pp.897-900
• /
• 2012

Cervical cancer resulting from prior infection with human papillomavirus (HPV) is a significant public health threat against young Japanese women. A national immunization plan to vaccinate 13~16 year old female students against HPV infection has been started in Japan since 2010, and may reach almost full coverage by the end of 2012. Older age females who may already be sexually active are not targeted by this plan but should follow safer sex practices as well as periodic screening of the cervix cytology to reduce their risk of developing cervical cancer. HPV vaccination alone does not offer full protection either, because only some HPV types are covered by the vaccines and the long-term efficacy of the vaccines has not been determined yet. Therefore, we did a survey at an international university in Japan to study the knowledge and attitude of female college students towards prevention of cervical cancer, to examine the age when they start sexual activity and other related attributes that may influence the risk of cervical cancer. We discuss the results of our survey and what they imply for the possible impact of an HPV immunization plan on the risk of cervical cancer in Japan, and conclude by an emphasis on the need to increase awareness among Japanese female adolescents and to enhance the cervical screening rates among older females who are already sexually active.

• 대기
• /
• 제21권2호
• /
• pp.143-149
• /
• 2011

A new multi-timescale analysis method, Ensemble Empirical Mode Decomposition (EEMD), is used to diagnose the variation of the MJO activity determined by 850hPa and 200hPa zonal winds from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis data for the 56-yr period from 1950 to 2005. The results show that MJO activity can be decomposed into 9 quasi-periodic oscillations and a trend. With each level of contribution of the quasi-periodic oscillation discussed, the bi-seasonal oscillation, the interannual oscillation and the trend of the MJO activity are the most prominent features. The trend increases almost linearly, so that prior to around 1978 the activity of the MJO is lower than that during the latter part. This may be related to the tropical sea surface temperature(SST). It is speculated that the interdecadal change in the MJO activity appeared in around 1978 is related to the warmer SST in the equatorial warm pool, especially over the Indian Ocean.