본 연구에서는 모드 I의 변동진폭하중 하에서 평판의 두께관통 균열성장을 예측하고 예측결과를 실험을 통해 검증하였 다. 균열성장 모델을 위해 과하중으로 인한 균열가속과 지연효과를 고려하는 Huang의 모델식을 이용하였다. 실험적 검증 을 위해 Al6016-T6 평판 균열을 제작하여 변동하중을 부여하고 균열길이를 일정 주기로 육안 측정하였다. 측정데이터로부 터 모델 변수를 추정하기 위해 베이지안 접근법에 기반한 파티클 필터 방법을 이용하였고, 이를 통해 위험크기까지의 미래 거동 및 잔존수명을 확률적으로 예측하였으며, 이를 실제 실험한 결과와 비교하였다. 그 결과 변동하중에 의한 균열지연이 잘 예측됨을 확인하였고, 측정 데이터가 증가할수록 예측된 중앙값(median)이 실제와 점점 더 일치하였다.

이 연구는 조합하중을 받는 변단면 변화곡선 보의 기하 비선형 수치해석 방법에 관한 연구이다. 보의 좌단은 회전지점이 고 우단은 마찰이 없는 활동(滑動)지점으로 지지되어 있어 하중이 작용하면 보의 축방향 길이가 증가하여 평형상태를 이룬 다. 조합하중은 회전지점에 작용하는 모멘트 하중과 집중하중을 고려하였다. 보의 단면은 휨 강성이 부재축을 따라 함수적 으로 변화하는 변단면으로 선택하였다. 이러한 보의 비선형 거동을 지배하는 연립 미분방정식을 Bernoulli-Euler 보 이론으 로 유도하였다. 이 미분방정식을 반복법으로 수치해석하여 보의 정확탄성곡선을 산정하였다. 이 연구의 이론을 검증하기 위하여 실험실 규모의 실험을 실행하였다.

In the region of the open cluster M48 (NGC 2548), time-series BV CCD images were taken for 22 nights from February 28 in 2008 to March 17 in 2011. From this observation, we found 10 new variable stars. They include five eclipsing binaries, an RR Lyrae, two δ Scuti, and two semi-periodic and/or slow irregular type variable stars. We fail to find the member stars of the open cluster among the 10 variable stars.

In accordance with increase of the leisure time due to the recent economical development of the people, since the interest on the cultural performance becomes high, the construction of various performance hall is on increasing in domestic. However, in case of the multi-purpose hall constructed in domestic, because the various genres performances are performed in the one space without any special variable equipment, those of many problems have been raised that unable to satisfy the acoustic capability suitable to the purpose of performance. In case of the performance place such as the multipurpose hall, it is the requiring real situation that the variable typed system-equipped performance hall which able to adjust the acoustic characteristics suitable to each performances. Accordingly, this study has ever predicted the optimized acoustic performance through computer simulation before-opening the hall, also has ever evaluated the acoustic performance through the actual survey after-opening the hall. It is considered that such study result could be utilized as the most useful material when construction the similar multipurpose hall equipped with the variable typed system, hereafter.

Variable precision rough set models have been successfully applied to problems whose domains are discrete values. However, there are many situations where discrete data is not available. When it comes to the problems with interval values, no variable prec

This paper proposes a variable sampling interval multivariate T² control chart with sampling at fixed times, where samples are taken at specified equally spaced fixed time points and additional samples are allowed between these fixed times when indicated

풍하중에 의해 발생된 진동을 저감함으로써 구조물의 내풍성능을 개선하기 위하여 동조질량감쇠기가 많이 사용되어 왔으며, 초고층 초장대 구조물과 같이 매우 큰 주기를 가지는 구조물에도 그 적용방안이 확대되고 있다. 구조물이 가지는 초장주기 특성에 의해 TMD의 거동 또한 초장주기 특성을 보유하게 되고 구조물 진동변위의 수 배에 이르는 질량 이송거리가 요구된다. TMD의 이송거리가 매우 커짐에 따라 TMD 설치공간을 초과할 뿐만 아니라 TMD를 구성하는 스프링, 가이드 레일과 같은 부품의 제조가 불가능하게 될 수 있다. 본 연구에서는 구조물의 제어성능을 유지하면서 이송거리(stroke)를 효과적으로 줄일 수 있는 새로운 타입의 TMD를 제안하고 이들이 구조물의 진동제어성능에 미치는 영향을 평가하였다. 제안하는 TMD는 이송거리에 따라 마찰력이 조정되는 장치로써 이송거리가 증가함에 따라 마찰력을 인위적으로 조절하여 최대 이송거리를 줄이는 시스템으로 이러한 변동마찰에 따른 구조물의 제어성능, 이송거리 저감을 초장주기 독립주탑을 대상으로 수치해석을 수행하엿다. 해석결과 본 연구에서 제안된 변동마찰형 TMD는 기존의 선형 TMD에 비해 이송거리를 크게 줄이면서 진동저감효과는 유사한 것으로 나타났다.

In the region of the intermediate open cluster M35 (NGC 2168), the time-series of V CCD images was taken for 12 nights from December 18, 2007 to September 25, 2010. From this observation, we detected 22 variable stars including 15 new ones. They are 6 δ Scuti, a Cepheid, an RR Lyrae, 9 eclipsing binaries and 5 semi-long periodic and/or slow irregular type variable stars. For the V photometry of the δ2 Scuti stars, the multi-frequency analysis was performed using the Discrete Fourier Transform and the linear least-square fitting.

The purposes of this study are to segment women consumers on the basis of clothing shopping orientation and to investigate clothing purchasing behaviors of each segmented group by age variable for development of effective fashion marketing strategies to meet very changeable modern consumers' needs. The research methodology is survey and subjects were 650 women aged from 20s to 60s. The questionnaire consist of measurement items for clothing shopping orientation, clothing purchasing behaviors and subjects' demographic attributions. The data were analyzed by Cronbach's α, factor analysis, cluster analysis, χ2 test, ANOVA and Duncan's multiple range test, using SPSS program. The results are as follows. First, 5 factors were emerged on clothing shopping orientation. Second, women consumers are segmented into 4 types(conspicuous, convenient, pleasurable, and unconcerned type) by clothing shopping orientation. Third, each consumer type divided by age variable showed some important differences on demographic characteristics and various clothing purchasing behaviors. Therefore, the results of this study support that clothing shopping orientation can be useful as one of the effective differentiated variables to segment women consumer market and age variable has important mediate effects on the differences of clothing purchasing behaviors by clothing shopping orientation type.

선박의 충돌회피동작의 전 단계로서 위험영역을 설정하고, 이 영역을 기준으로 위험영역과 안전영역을 경계지우기 위한 많은 연구가 이루어져 왔다. 본 연구는 가변 위험영역을 설정하기 위하여 시간의 함수로서 주어진 접근 파라미터 분석을 통하여 적절한 충돌회피 동작을 위 한 필요한 목적함수를 제시하는데 목적이 있다. 종래의 연구방법들이 가질 수 있는 DCPA 및 TCPA에 기반을 둔 위험영역의 설정 및 충돌회피 의 설정법이 가질 수 있는 문제점의 보완은 실 환경에 적용 가능한 충돌회피 알고리즘 개발의 토대를 이룬다. 단순한 DCPA 및 TCPA에 따른 충돌회피 동작의 판단은 주어진 항해상황에 적정하지 못 할 수 있다.

Next to Paper I (Jeon 2009a), time-series BV CCD images of the open cluster M38 were taken for 4 nights on December, 2009. The observations have been carried out for total 27 nights. In addition to the 20 variable stars in the Paper I, the discovery of 44 new variable stars has been presented in this paper: 6δ Scuti stars, 2γ Doradus stars, 18 eclipsing binaries and 18 semi-long periodic and/or slow irregular type variable stars. For the V photometry of the δ Scuti and γ Doradus stars, multi-frequency analysis was performed using the Discrete Fourier Transform and linear least-square fitting. The period search for the eclipsing binaries and the semi-long periodic and/or slow irregular type variable stars was performed by phase fitting method. As a result, the periods for 23 variable stars among the 44 ones were defined.

Two kinds of oxide-dispersion-strengthened (ODS) 316L stainless steel were manufactured using a wet mixing process(wet) and a mechanical alloying method (MA). An MA 316L ODS was prepared by a mixing of metal powder and a mechanical alloying process. A wet 316L ODS was manufactured by a wet mixing with 316L stainless steel powder. A solution of yttrium nitrate was dried after being in the wet 316L ODS alloy. The results showed that carbon and oxygen were effectively reduced during the degassing process before the hydroisostatic process (HIP) in both alloys. It appeared that the effect of HIP treatment on increase in impact energy was pronounced in the MA 316L ODS alloy. The MA 316L ODS alloy showed a higher yield strength and a smaller elongation, when compared to the wet 316L ODS alloy. This seemed to be attributed to the enhancement of bonding between oxide and matrix particles from HIP and to the presence of a finer oxide of about 20 nm from the MA process in the MA 316L ODS alloy.

From the short-period variability survey (SPVS) in Bohyunsan Optical Astronomy Observatory, I obtained time-series BV CCD images in the region of the young open cluster M29 (NGC 6913) for 15 nights from May 30, 2008 to September 17, 2009. I observed 48 variable stars including 45 new ones. They consisted of 5 δ Scuti, a Cepheid, 16 eclipsing binaries and 24 semi-long periodic and/or slow irregular type variable stars including β Cephei and LPB type stars. For the rest two ones, the type of variability was not defined. I also checked the variability of the 26 known variable stars listed in the GCVS. Only three ones among 26 known variable stars confirmed variability.

From the short-period variability survey (SPVS) in Bohyunsan Optical Astronomy Observatory, we obtained time-series BV CCD images in the region of an open cluster M38 (NGC 1912) for 23 nights from February 1, 2007 to December 7, 2008. We found 18 δ Scuti stars and 2 γ Doradus stars. Among them, only 3 δ Scuti stars were known ones. From the color-magnitude diagram (CMD) of M38, most of them have been located in the instability strip. The two γ Doradus stars have been located within γ Doradus strip of M38. But, only four δ Scuti stars were located within radius 10' from the center of M38. To confirm of their membership for M38, we need more study, such as, proper motion by spectroscopic observation.

This article reports the spectral behavior of CH Cygni, using data obtained in October 2005 and June 2006. In these epochs, CH Cygni showed emission lines of H I, Fe II, [Fe II], [O III], [N II], [Ne III] and [S II]. Many of these lines were more enhanced since 2004. The underlying M-type spectrum was removed to get the intrinsic emission profile, and the resulting profiles were deconvoluted into several Gaussian components. Also, the radial velocities for all the lines that appeared in these spectra of CH Cygni were measured. The resultant lines were compared with each other and with those obtained in 2004; the findings are explained in terms of an accretion disk and jets.