• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권2호
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• pp.81-89
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• 1999

This study estimates the correlation dimensions of the land-sea breeze phenomenon, that has a clear diurnal cycle, in order to gain a more detailed understanding of this phenomenon. The data adopted include north-south wind velocity component(v) and temperature(T) time series that were observed at Kimhae Airport and Inje University over a period of 5 days, from the 4th to the 8th of August, 1994. The embedding phase space of the time series were reconstructed from 2 to 14 dimensions, and the correlation dimensions of the attractors were then estimated. The results show that the land-sea breeze phenomenon exhibits a deterministic chaos with non-integer correlation dimension values between 2 and 3. Accordingly, 3 is the minimum number of independent variables required to model the dynamics of the landsea breeze phenomenon in the Kimhae area. Since the saturated embedding dimension, when the correlation dimension remains unchanged, is larger for the wind velocity v-component than for temperature, this indicates that wind velocity is susceptible to topology.

• 한국정보통신학회논문지
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• 제8권3호
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• pp.541-546
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• 2004

시공간 부호(Space-Time Coding)는 송신부에서 전송신호를 시간영역과 공간영역으로 확장하여 전송하는 기법으로 다이버시티 이득과 부호화 이득을 동시에 얻을 수 있다. 본 논문에서는 SPW(Signal Processing Worksystem) 시뮬레이션 플랫포옴을 이용하여 고속 무선랜 관련 표준안인 IEEE 802.11a 시스템을 기초로 한 연접부호 시공간 OFDM 시스템의 성능 개선을 분석하였다. IEEE 802.11a에 포함된 구속장의 길이가 7인 콘볼루션 부호 대신에, 시공간 블록 부호를 이용한 시스템과 콘볼루션 부호와 시공간 블록 부호를 연접한 시스템을 SPW 시뮬레이션 플랫포옴에서 각각 구현하여 그 성능을 비교하였다. SPW 시뮬레이션 결과에 의하면 데이터율 6Mbps에서 두 부호를 연접한 시스템의 성능이 콘볼루션 부호기를 적용한 IEEE 802.11a 시스템보다 약 5dB 이상 우수한 성능을 보였고 데이터을 12Mbps에서는 6dB 이상의 성능 개선을 얻을 수 있었다.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.25-32
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• 2013

We statistically investigated the properties of low-latitude Pi2 pulsations using Bohyun (BOH, Mlat = $29.8^{\circ}$, L = 1.35) ground magnetometer data in 2008. For this 1-year interval, 582 Pi2 events were identified when BOH was in the nightside from 1800 to 0600 local times. We found the following Pi2 characteristics. (1) The occurrence distribution of Pi2s is relatively constant in local times. (2) The Pi2 frequency varies in local times. That is, Pi2 pulsations in postmidnight sector had higher frequency than in premidnight sector. (3) Pi2 power in premidnight sector is stronger than in postmidnight sector. (4) Pi2 frequency has positive correlation with solar wind speed and AE index. (5) Pi2 power has not a clear correlation with solar wind parameters. This indicates that Pi2 power is not controlled by external sources. (6) It is found that the most probable-time between Pi2 onsets is ${\Delta}t$ ~ 37.5 min: This is interpreted to be the period between Pi2 pulsations when they occur cyclically. We suggest that ${\Delta}t$ ~ 37.5 min is the occurrence rate of reconnection of open field lines in the tail lobe.

• 전기학회논문지P
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• 제58권4호
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• pp.511-515
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• 2009

For detecting of the faulty insulator, Correlation Propagation Neural Networks(CPNN) has been proposed. Faulty insulator is reduced the rate of insulation extremely, and taken the results dirty and injured. It is necessary to detect the faulty insulator and exchange the new one. And thus, we have designed the CPNN to be detected that insulators by the real time computation method through the inter-node diffusion. In the network, a node corresponds to a state in the quantized input space. Each node is composed of a processing unit and fixed weights from its neighbor nodes as well as its input terminal. Information propagates among neighbor nodes laterally and inter-node interpolation is achieved. 1-D CPNN hardware has been implemented with general purpose. Experiments with static and dynamic signals have been done upon the CPNN hardware. Through the results of simulation experiments, we define the ability of real-time detecting the faulty insulators.

• 통합자연과학논문집
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• 제5권2호
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• pp.120-126
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• 2012

This paper describes the algorithm that lowers the dimension, maintains the gesture recognition and significantly reduces the eigenspace configuration time by combining the higher correlation feature information and Principle Component Analysis. Since the suggested method doesn't require a lot of computation than the method using existing geometric information or stereo image, the fact that it is very suitable for building the real-time system has been proved through the experiment. In addition, since the existing point to point method which is a simple distance calculation has many errors, in this paper to improve recognition rate the recognition error could be reduced by using several successive input images as a unit of recognition with K-Nearest Neighbor which is the improved Class to Class method.

• Journal of Astronomy and Space Sciences
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• 제26권3호
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• pp.287-294
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• 2009

In helioseismology it is normally assumed that p-mode oscillations are excited in a statistically independent fashion. Unfortunately, however, this issue is not clearly settled down in that two experiments exist, which apparently look in discrepancy. That is, Appourchaux et al. (2000) looked at bin-to-bin correlation and found no evidence that the assumption is invalid. On the other hand, Roth (2001) reported that p-mode pairs with nearby frequencies tend to be anti-correlated, possibly by a mode-coupling effect. This work is motivated by an idea that one may test if there exists an excess of anticorrelated power variations of pairs of solar p-modes. We have analyzed a 72-day MDI spherical-harmonic time series to examine temporal variations of p-mode power and their correlation. The power variation is computed by a running-window method after the previous study by Roth (2001), and then distribution function of power correlation between mode pairs is produced. We have confirmed Roth's result that there is an excess of anti-correlated p-mode pairs with nearby frequencies. On the other hand, the amount of excess was somewhat smaller than the previous study. Moreover, the distribution function does not exhibit significant change when we paired modes with non-nearby frequencies, implying that the excess is not due to mode coupling. We conclude that the origin of this excess of anticorrelations may not be a solar physical process, by pointing out the possibility of statistical bias playing the central role in producing the excess.

• 융합신호처리학회논문지
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• 제17권2호
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• pp.53-60
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• 2016

본 논문에서는 대전상관기의 전체 성능을 달성하기 위해 새로운 방식의 상관자료 수집장치의 구축과 시험결과에 대해 소개한다. 최근 한국우주전파관측망(Korean VLBI Network, KVN)의 최대 관측규격인 8Gbps 속도의 관측이 수행되고 있으며, 대전상관기를 이용한 상관처리도 요구되고 있기 때문에 노후 장치를 대체하여 최대 상관처리 속도에 대응하기 위한 새로운 상관자료 수집장치의 도입이 필요하게 되었다. 대전상관기의 최대 상관결과 출력속도는 25.6ms 적분시간에 대해 초당 1.4GB/sec이다. 기존에 도입한 상관자료 수집장치는 대전상관기의 최대 상관출력 속도에 대응하지 못해 출력속도를 1/4로 제한하여 활용되었다. 즉, 대전상관기의 입력포트 4개 중에 관측속도 1Gbps에만 대응하도록 3개의 입력은 제한하였다. 이번에 도입한 장치는 스토리지 시스템에서 활용되고 있는 여러 최신의 기술 중에서 Gluster 파일 시스템을 사용하고 있으며, 대전상관기의 최대 출력속도인 1.4GB/sec를 만족하는 시험에서 광 출력 4개에 대해 각각 350MB/sec, 총 1.4GB/sec의 결과를 얻었다.

• 한국실내디자인학회논문집
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• 제24권3호
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• pp.156-164
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• 2015

Nursing Homes do not have a defined standard in the space area nor does it have a detailed standard facility requirement by law. This can possibly lead to the deterioration of the facility and the system. This directly affects the medical treatment space area within the nursing home. The medical treatment area provides medical treatment to seniors and this is where the seniors get most of their daily services. Therefore, this is research is about the study of the space area of the medical center and the ratio trend of the space area for the medical treatment facility located in senior nursing homes. Ten facilities have been selected in this study to analyze the correlation factors between space area and its trends. The analysis performed includes the conditions relating to the area and what affects the center. We have followed up with a proposal for improvement of the facility and area configuration for the medical treatment facility. Based on the analysis, the following conclusion can be made: First, the senior welfare centers are mostly used as a residence purpose followed a temporary stay of residence facility for the seniors. Second, research indicates that the bigger the facility, nursing and public functions took a larger portion of the space area compared to other services within the senior welfare centers. Third, the study shows the management space area took up about 1%~6% of the entire medical center within the nursing home which is a narrow space area because of the integrated management. Fourth, analysis based on the trend in the time-series indicate after the adoption of the system, there is a continued decline in the space area of nursing, management and public areas. Lastly, since before and after 2008, the space area composition of the nursing facility shows a continuous decline in our study. We can safely conclude that the revised senior welfare act's construction plan has an effect in the facility and is effectively working to meet its requirement. Therefore, the revision of the law is required to reflect the social needs of the residents.

• Steel and Composite Structures
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• 제20권2호
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• pp.399-412
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• 2016

This paper evaluates the seismic response of three dimensional steel space buildings using the spread plastic hinge approach. A numerical study was carried out in which a sample steel space building was selected for pushover analysis and incremental nonlinear dynamic time history analysis. For the nonlinear analysis, three earthquake acceleration records were selected to ensure compatibility with the design spectrum defined in the Turkish Earthquake Code. The interstorey drift, capacity curve, maximum responses and dynamic pushover curves of the building were obtained. The analysis results were compared and good correlation was obtained between the idealized dynamic analyses envelopes with and static pushover curves for the selected building. As a result to more accurately account response of steel buildings, dynamic pushover envelopes can be obtained and compared with static pushover curve of the building.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권1호
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• pp.88-88
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• 2004

We demonstrate that the flux levels of post-storm relativistic electrons are well correlated with the amount of electrons of the energy about 100 keV injected during substorms, while the power of ULF is more or less related to the spectral hardening of these seed electrons. Hence, the existence of ULF alone during the storm time does not necessarily cause flux increase of relativistic electrons as storms do not always generate sufficient amount of seed electrons of this energy range. (omitted)