• 산업경영시스템학회지
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• 제46권3호
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• pp.59-68
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• 2023

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

• 터널과지하공간
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• 제33권5호
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• pp.425-434
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• 2023

TBM 디스크 커터의 마모량을 실시간 계측하기 위해서는 센서를 이용해 계측을 자동화하는 것뿐만 아니라, 계측된 데이터를 후방의 정보처리시스템에 안정적으로 전송하는 것도 중요하다. 본 연구에서는 TBM 커터헤드에 설치된 센서로부터 챔버 후방에 설치된 수신기로 데이터를 무선 전송할 때 저전력 블루투스(Bluetooth Low Energy, BLE) 기술의 활용 가능성을 검토하였다. 실험실 모사 실험을 통해 송신기의 신호강도, 송신기와 수신기 사이의 거리, 챔버 공간에 채워진 물질의 종류에 따라 변화하는 수신기의 신호 수신 강도(Received Signal Strength Index, RSSI)의 특성을 분석하였다. 송신기의 신호강도를 0 dBm 이상으로 설정하면 실험에서 고려한 모든 이격거리 조건과 챔버의 상태 조건에서 데이터를 무선 전송할 수 있었다.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.63-71
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• 2007

The conversion efficiency, durability and pressure drop of the automotive exhaust catalysts are dependent on the flow distribution within the substrate. Conventional porous medium approaches assuming monolith resistance based on the one-dimensional laminar flow for simulating the flow through the automotive exhaust catalysts over-predict the flow uniformity in the monolith. In this study, additional pressure loss is also considered by accounting for entrance effects due to the oblique flow incident on the front face of monolith as a consequence of flow separation and recirculation within the diffuser. The incorporation of an additional pressure loss improves the predictions for the maximum flow velocity within the substrate. An numerical study has also been conducted for the three-dimensional unsteady incompressible non-reacting flow inside various dual-monolith catalytic converters for the rapid acceleration/deceleration driving.

• 환경영향평가
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• 제21권5호
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• pp.781-787
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• 2012

The purpose of this study was to analyze the landscape changes at Su-ji and Gi-heung in Young-in city using FRAGSTATS Model. Landscape Indices obtained by this model can explain the structural change of urban green zone and fragmentation resulting from development. As results of this study, Gi-heung showed worse quality of landscape in 2007, comparing 2000. However, in Su-ji, there were several better landscape indices in the same 2007/2000 comparison, even though the little shrinking of green zone and separation of core area. It could assume that the reason was caused by conservation policy of urban green zone. This study could provide the useful methods for finding the problems and searching the alternatives considering the development of urban green zone.

• 한국콘텐츠학회논문지
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• 제7권8호
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• pp.1-12
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• 2007

본 논문은 스테레오 사운드에서 합쳐지기 이전의 개별적인 사운드를 분리해내는 기법을 제안한다. 기존의 Degenerate Unmixing Estimation Technique (DUET) 알고리즘의 W-Disjoint Orthogonal 가정에 기반을 두고 있으며, Windowed-Fourier 변환을 사용하여 시간-주파수 영역에서 주요 프로세스를 수행한다. 제안된 방식은 패닝 인덱스의 거리차이에 따라 가중치를 준 마스크를 사용하는 기법과 양쪽 채널의 성분을 비교하여 바이너리 기반의 마스크를 사용하는 방식이다. 전자는 부드러운 분리 특성을 보여주며, 후자는 높은 분리 특성을 보여주었다. 마지막에 실험을 통해 기존의 방식과 제안된 방식을 비교함으로써, 제안된 방식이 기존 방식 보다 좋은 성능을 가지고 있음을 알아볼 것이다.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.1-8
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• 2006

많은 연구자들이 자동 염색체 핵형 분류와 해석을 연구하고 있다. 현미경상의 이미지를 개개의 염색체로 자동 분류하기 위해서는 이미지 전처리 핵형 분류기 구현 등의 세부 절차가 필요하다. 이미지 전처리에서는 개개의 염색체 분리, 잡음 제거, 특징 파라미터 추출을 진행한다. 추출된 형태학적 특징 파라미터는 동원체 지수, 상대 길이비, 상대 면적비이다. 본 논문에서는 인간 염색체 핵형 분류를 위하여 퍼지 분류기가 사용되어졌다. 추출된 형태학적 특징 파라미터가 퍼지 분류기의 입력 파라미터로 사용되었다. 우리는 개개의 염색체 그룹에 대한 최적 퍼지 분류기를 위하여 멤버쉽 함수를 선택하는 것을 연구하였다.

• 아동학회지
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• 제6권1호
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• pp.75-92
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• 1985

The purpose of this study was to investigate the relationship between the psychological/physical home environment, and children's moral judgement and moral behaviors. The subjects for this study were a normal group of 58 children and a delinquent group of 54 children. The normal children were selected from elementary and middle schools in Taegu city, and the delinquent children were from two juvenile prisons in the Taegu area. Children's moral judgement scores were measured by levels of moral judgement as conceptualized by Kohlberg. The major findings of this study were that: 1) There were significant differences between the normal and delinquent groups on democratic conduct, permissive attitude, degree of intimacy between parent and child, and materialism orientation. 2) There were significant differences between the normal and delinquent group on life or death of real parent, living with parents, separation, bereavement or divorce, mother's age, father's educational level, and father's occupational level. 3) There were significant differences between the normal and delinquent group on children's moral judgement scales. 4) Father's educational level was the best index for predicting psychological and physical home environment variables and differences between normal and delinquent children on level of moral judgement.

• 천문학회보
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• 제35권1호
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• pp.69.1-69.1
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• 2010

IC 443 is famous for its interaction with nearby molecular clouds and intense H2 emission lines in infrared. Therefore, it has been studied extensively for the understanding of molecular shocks. We observed H2 mission lines toward the shock-cloud interaction regions of IC 443, known as clumps B, C, and G. The observations were performed with the InfraRed Camera (IRC) onboard a satellite AKARI over 2.5-5.0 um, where previous space observations, e.g. Infrared Space Observatory (ISO) and Spitzer, do not cover. Our AKARI observations provide spectra of sequential pure-rotational and ro-vibrational H2 emission lines. For the clumps C and G, combining with previous mid-infrared observational results, we found that the H2 level populations show a significant separation between v=0 and v=1 levels; v=1 levels are under-populated than v=0 levels, therefore, the population cannot be described by two temperature LTE model, as many people have analyzed for the shocked H2 gas. We also applied the thermal admixture model, dN(H2; T)~T^(-b) dT, with varying ortho-to-para ratios according to the temperature, to describe the level population, and obtained plausible ranges of the H2 gas density and power-law index b.

• 가정∙방문간호학회지
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• 제24권1호
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• pp.34-43
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• 2017

Purpose: The purpose of this study was to provide basic data to develop a Fall Prevention Education Program by comparing and analyzing fall experiences and the factors that influence elderly people with dementia suffering falls. Methods: The participants were 302 patients with dementia aged 60 years or older with nursing records of hospitalization in three nursing homes located in a metropolitan area. The SPSS/Win 21.0 package was used to analyze the collected data. A logistic regression analysis was performed to identify the influence factors related to fall experiences. Results: For men, fall experiences were more frequent given the following factors: overweight; high fall risk tendency; aged 90 and above; married; dementia duration period of 5 to 9 years; and taking medication for dementia. For women, the factors included age range of 80 to 89; overweight; obese; both low and high fall risk tendency; separation by death; and having spent less than 1 year in nursing homes. Conclusion: We anticipate positive results in fall prevention education programs for the elderly with dementia if the results of this study are used as basic data, and interventions are customized to consider the sex and the relevant influence factors as to fall experiences.

• Steel and Composite Structures
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• 제28권3호
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• pp.331-347
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• 2018

In this paper history of stresses, strains, radial and circumferential displacements of a functionally graded thick-walled hollow cylinder due to creep phenomenon is investigated. The cylinder is subjected to an arbitrary non-axisymmetric two dimensional thermo-mechanical loading and uniform magnetic field along axial direction. Using equilibrium, strain-displacements and stress-strain relations, the governing differential equations of the problem containing creep strains are derived in terms of radial and circumferential displacements. Since the displacements are varying with time due to creep phenomenon, an analytical solution is not available for these equations. Thus, a semi-analytical procedure based on separation of variables and Fourier series together with a numerical procedure is employed. The numerical results indicate that the non-axisymmetric loading and the material grading index have significant effect on stress redistributions. Moreover, by proper selection of material for any combination of non-axisymmetric loading, one can arrive suitable response for the cylinder to achieve optimal design. With some simplifications, the results are validated with the existing literature.