• Journal of Information Processing Systems
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• 제19권3호
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• pp.310-322
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• 2023

Although the network environment is gradually improving, the virtual nature of the network is still the same fact, which has brought a great influence on the supervision of Weibo network public opinion dissemination. In order to reduce this influence, the user information of Weibo network public opinion dissemination is studied by using Python technology. Specifically, the 2019 "Ethiopian air crash" event was taken as the research subject, the relevant data were collected by using Python technology, and the data from March 10, 2019 to June 20, 2019 were constructed by using the implicit Dirichlet distribution topic model and the naive Bayes classifier. The Weibo network public opinion user identity graph model under the "Ethiopian air crash" on June 20 found that the public opinion users of ordinary netizens accounted for the highest proportion and were easily influenced by media public opinion users. This influence is not limited to ordinary netizens. Public opinion users have an influence on other types of public opinion users. That is to say, in the network public opinion space of the "Ethiopian air crash," media public opinion users play an important role in the dissemination of network public opinion information. This research can lay a foundation for the classification and identification of user identity information types under different public opinion life cycles. Future research can start from the supervision of public opinion and the type of user identity to improve the scientific management and control of user information dissemination through Weibo network public opinion.

• 한국항해학회지
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• 제20권1호
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• pp.81-85
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• 1996

The defects occurred in knitted fabrics have several types due to some trouble sources. In particular, the defects caused by knitting machine troubles give a serious damage to the whole webs. It is, therefore, necessary to discriminate the kind of defects. The method to discriminate the type and size of defects has been proposed, which is used a pair of narrow band eliminating spatial filters. This method is based upon an isotropic signal processing in time domain. This paper is to confirm that the proposed method can be useful in the discrimination of defects, having analyzed in spatial frequency domain.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권1호
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• pp.7-12
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• 2016

사용자 인터페이스는 프로그램 상호 연동의 중요한 요소가 된다. 사용자 인터페이스에서 발생되는 오류는 전체 시스템에 영향을 주게 되고, 그 결과 고객의 만족도가 낮아진다. 따라서 도메인 단계에서 신뢰성 있는 분석을 위하여 사용자 인터페이스의 형태를 분석할 수 있는 방법이 필요하게 된다. 본 논문에서는 이와 같은 문제를 해결하기 위하여 도메인 분석의 신뢰성 향상을 위한 사용자 인터페이스의 추출 방법과 기준을 제시하고자 한다.

• 한국인터넷방송통신학회논문지
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• 제11권3호
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• pp.93-98
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• 2011

본 논문은 마커 기반의 증강현실 시스템을 이용하여 사용자의 지능 개발을 위한 게임형 인지 재활 시스템을 제안한다. 기존의 인지 재활은 타인의 도움을 받거나 키보드나, 마우스 조작을 필요로 하는 불편을 해소 하고자, 마커 카드 제어만을 통해 진행 되는 방식을 적용하였다. 이를 위해 카메라를 통해 얻은 영상의 보정을 위한 영상처리 과정과 마커 검출 및 증강 표현이 가능하도록 하였다. 제시된 완성 모형의 회전을 통해 전체 형태를 확인하고, 멀티 마커의 조합을 통해서 원하는 오브젝트 완성이 가능하며, 대화형 방식으로 처리되어 사용자에게 흥미와 치료에 대한 집중도를 증진할 수 있도록 하였다.

• 대한원격탐사학회지
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• 제34권1호
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• pp.141-150
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• 2018

Crop type classification is essential for supporting agricultural decisions and resource monitoring. Remote sensing techniques, especially using hyperspectral imagery, have been effective in agricultural applications. Hyperspectral imagery acquires contiguous and narrow spectral bands in a wide range. However, large dimensionality results in unreliable estimates of classifiers and high computational burdens. Therefore, reducing the dimensionality of hyperspectral imagery is necessary. In this study, the Random Forest (RF) classifier was utilized for dimensionality reduction as well as classification purpose. RF is an ensemble-learning algorithm created based on the Classification and Regression Tree (CART), which has gained attention due to its high classification accuracy and fast processing speed. The RF performance for crop classification with airborne hyperspectral imagery was assessed. The study area was the cultivated area in Chogye-myeon, Habcheon-gun, Gyeongsangnam-do, South Korea, where the main crops are garlic, onion, and wheat. Parameter optimization was conducted to maximize the classification accuracy. Then, the dimensionality reduction was conducted based on RF variable importance. The result shows that using the selected bands presents an excellent classification accuracy without using whole datasets. Moreover, a majority of selected bands are concentrated on visible (VIS) region, especially region related to chlorophyll content. Therefore, it can be inferred that the phenological status after the mature stage influences red-edge spectral reflectance.

• 소성∙가공
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• 제8권3호
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• pp.241-241
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• 1999

With the aim of assessing the degradation of Zr-2.5Nb pressure tubes operating in the Wolsong unit-1 nuclear power plant, characterization tests are being conducted on irradiated Zr-2.5Nb tubes removed after 10-year operation. The examined tube had been exposed to temperatures ranging from 264 to 306℃ and a neutron fluence of 8.9×$10^{21}$ n/cm²(E>1 MeV) at the maximum. Tensile tests were carried out at temperatures ranging from RT to 300℃. The density of a-type and c-type dislocations was examined on the irradiated Zr-2.5Nb tube using a transmission electron microscope. Neutron irradiation up to 8.9×$10^{21}$ n/cm²(E>1 MeV) yielded an increase in a-type dislocation density of the Zr-2.5Nb pressure tube to 7.5×$10^{14} m^{-2}$, which was highest at the inlet of the tube exposed to the low temperature of 275℃. In contrast, the c-component dislocation density did not change with irradiation, keeping an initial dislocation density of 0.8×$10^{14} m^{-2}$ over the whole length of the tube. As expected, the neutron irradiation increased mechanical strength by about 17-26% in the transverse direction and by 34-39% in the longitudinal direction compared to that of the unirradiated tube at 300℃. The change in the mechanical properties with irradiation is discussed in association with the microstructural change as a function of temperature and neutron fluence.

• 환경위생공학
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• 제17권3호
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• pp.60-66
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• 2002

Iksan city is planning to construct a waste incinerator on the site of about $110,000\textrm{m}^2$ in size that will be selected from a public bid(Oct.~Nov.2002)in the wake of expiration by June 2003 of use for Hamyeol fill-up ground. Science it has usually been difficult to find sites for filling-up or incinerating facilities owing to NIMBY phenomenon, it is badly requested to employ up-to-date technology for processing wastes without environmental pollution. The conflicts between the administrative authorities and community people with regard to construction of incineration facilities, fill-up ground and facilities for waste processing or recycling are not the matters of just today but are increasingly deepening and spreading countrywide. There seems to be no prospect for these conflicts to be amicably settled through dialogues. They rather become a social disease inflicting the whole country like an epidemic. It is therefore believed to be necessary to introduce measures to design and build environment-friendly facilities that may be accepted by residents as not abominable ones but be used as amusing place while they watch the daily operation of them as watchdogs. Iksan city's plan to construct environment-friendly waste incineration facilities of pyrolysis type without chimney has undergone the process of public hearings and explanatory gatherings from every class of Iksan citizens to get consensus but is still delayed due mainly to be the failure of inducing foreign investments. Pyrolysis technology has two advantages ; first, environment-friendly due to less emission of second pollutants ; second, production of by-products highly valuable as resources. It Is known that Germany has recently begun installation and operation of pyrolysis facility urban wastes, an evidence indicating that pyrolysis method will be widely applied to cope with the tightened regulation to preserve environment worldwide.

• 한국진공학회지
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• 제18권5호
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• pp.337-345
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• 2009

패키지 기판의 지름 $100{\mu}m$ 이하 미세 드릴 구멍의 경우 습식 디스미어 공정만으로는 구멍 내부의 스미어를 효과적으로 제거할 수 없다. 본 연구에서는 습식 디스미어 공정의 이전 단계에서 대기압 플라즈마를 처리하여 소수성의 기판 표면을 친수성으로 개질하고자 하였다. 대기압 플라즈마 공정은 리모트 DBD 방식의 전극을 이용하여 패키지 제조 공정에 적합한 인라인 형태의 장비로 구성되었다. 대기압 플라즈마를 처리한 결과 접촉각 기준으로 $71^{\circ}$의 소수성 절연 필름 표면이 $30^{\circ}$ 정도의 친수성 표면으로 개질되었다. 대기압 플라즈마 처리 유무에 따른 습식 디스미어 공정의 특성을 평가하기 위하여 절연 필름의 두께, 드릴 구멍 지름, 표면 조도의 변화를 측정하였는데, 대기압 플라즈마 처리 시 기판 전면에서 공정 특성의 균일도가 향상되는 것을 확인하였다. 또한 대기압 플라즈마 처리 유무에 따른 드릴 구멍의 SEM 사진 분석 결과 대기압 플라즈마 처리 시 구멍 내부의 스미어가 효과적으로 제거됨을 실험적으로 확인하였다.

• Journal of Biosystems Engineering
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• 제15권3호
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• pp.207-218
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• 1990

Grains display characteristics of both elastic bodies and viscous fluids when they are subjected to mechanical treatments in harvesting, handling, and processing. This viscoelastic behavior of grains when mechanically stressed must be fully understood to establish maximum machine efficiency and have a minimum degree of grain damage and the highest quality of the final product. The studies were conducted to examine the effect of the moisture content, the loading rate and the initial deformation on the stress relaxation behavior of whole kernel of rough rice, and develop the rheological model to represent its stress relaxation behavior. The following results were obtained from the study. 1. Moisture content had the greatest influence on the initial portion of the relaxation curve. With elapsing time the lower moisture content resulted in the lower residual stress for the Japonica-type rough rice and vice versa for the Indica-type rough rice. But within the ranges of moisture content tested, the degree of stress relaxation per unit strain on the Indica-type rough rice was a little higher than those on the Japonica-type rough rice. 2. The slower loading rate resulted in less initial stress. The decreasing trend of residual stress for all the samples tested with increasing loading rate was shown. 3. The higher initial deformation for all the samples resulted in less initial stress. The increasing of amount of stress relaxation per unit strain with increase of initial stress indicated that viscoelastic properties of rough rice depended not only upon duration of load applied but also initial stress applied. This means that rough rice is nonlinear viscoelastic material. 4. The compression stress relaxation properties of rough rice kernel can be described by a generalized Maxwell model representing by the Maxwell elements.

• 대한전자공학회논문지TC
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• 제47권11호
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• pp.24-29
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• 2010

선택적 중계 기법은 수신 복잡도가 낮으면서도 선택 다이버시티로 인하여 성능 향상을 도모할 수 있는 협력 통신 시스템의 전송 기법 중 하나이다. 본 논문에서는 이 시스템의 오차 확률을 최소화 할 수 있는 선형 전처리 기술을 다룬다. 전 채널 상태 정보가 모든 단말에서 이용 가능하다는 가정 하에, 수신 신호의 평균 제곱 오차를 최소화하기 위한 송신 및 중계 전처리 필터를 제안한다. 중계 전송을 위한 최적의 송신 및 중계 전처리 필터는 수식적으로 표현하기 어렵고 반복 연산을 요구하므로 이를 단순화한 기법을 적용한다. 게다가, 고정된 신호 대 잡음비의 임계치를 사용하는 기존의 선택적 중계 기법과 달리 직접 경로와 중계 경로에서의 신호 검출 후 최소 신호 대 잡음비를 비교하여 더 큰 값을 갖는 경로를 전송 경로로 선택하는 기법을 소개한다. 모의실험을 통하여 제안한 선택 중계 기법이 기존의 중계 기법 및 선택적 중계 기법보다 우수한 성능을 보임을 확인할 수 있다.