• Journal of Ecology and Environment
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• 제34권3호
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• pp.259-267
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• 2011

A pollen analytical study of sediment sequences collected from Yongneup moor (sampling point: $38^{\circ}$12'57.4" N, $120^{\circ}$7'30.2" E) was conducted to understand the vegetation history in the mountainous region of the central Korean peninsula. Carbon dating was carried out to measure five successive samples obtained from the bottom at a depth of 180 cm to the surface. The Yongneup moor sediment revealed four main local pollen zones; that is, four past vegetation phases as follows: Local pollen zone I: Quercus-Pinus zone; estimated age, 5,900-4,800 calibrated years (cal) before present (BP); vegetation type, cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone II: Pinus-Abies-Quercus zone; estimated age, 4,800-3,400 cal BP; vegetation type, cool-temperate northern/alti-montane mixed coniferous and deciduous broad-leaved forest. Local pollen zone III: Quercus-Pinus-Abies zone; estimated age, 3,400-400 cal BP; vegetation type: cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone IV: Pinus-Quercus zone; estimated age, 400-present cal BP; vegetation type, cool-temperate central/montane mixed deciduous broad-leaved and coniferous forest. It was confirmed that subalpine coniferous forests had expanded to the mountainous region of the central Korean peninsula during the period from 4,800-3,400 cal BP and thereafter deciduous forests dominated by Q. mongolica were established. Notably, secondary forests dominated by P. densiflora developed in the lower part of the mountainous region of the central Korean peninsula about 400 cal BP due to human interference.

• Child Health Nursing Research
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• 제5권1호
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• pp.59-69
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• 1999

The main purpose of this study is to identify nursing needs of parents who have hospitalized child. Research design is a descriptive survey. The subjects for the study were 79 parents who have hospitalized child at a pediatric ward of one of the general hospital attached to a university in J city. The data was collected by researchers using a structured questionnaire. The questionnaire was Likert type 5 point scale, composed of 5 categories with 61 items. The data was analyzed by SPSS/PC. The results of the study were as follows ; 1) Mean score of nursing needs of subjects were 3.93 at 2nd day of admission and 3.99 at 7th day of admission. 2) Among the categories, the highest nursing need at the End day and 7th day of admission was ‘dilect nursing’, in desending order, ‘facilities and environment’, ‘education and counseling’, ‘nursing assessment’. The lowest nursing need was ‘reference’. 3) Differences between the nursing needs of subjects at 2nd day and 7th day were as follows : (1) By categories, there was a significant difference only in the ‘reference’ categoly(t=2.74, P=.008). (2) By items, there were significant differences in items of ‘to check necessary materials(t=2.31, P=.024)’, ‘to understand family function and family relationship(t=2.12, P=.041)’, ‘to set up study room(t=2.22, P=.030)’, and ‘to mediate parent's meeting group(t=3.89, P=.000)’. The above result indicated that nursing needs of parents with hospitalized child were above average, especially very high in items about disease process, and items directly associated with treatment and nursing care. So, nurses have to focus on information about the patient's state of disease, treatment, test and procedure, and in efficiently giving direct nursing care to implement mure effective care for the hospitalized children and their parents. And some future researche is needed to identify the difference of degree of nursing needs of parents with hospitalized child according to admission duration using a different sample and a longer sampling interval.

• International Journal of Concrete Structures and Materials
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• 제1권1호
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• pp.83-88
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• 2007

This paper discusses a method of measuring transient potential response of a corrosion interface to a small galvanostatic pulse perturbation for a rapid assessment of the corrosion rate of reinforcing steel in concrete structures. Measurements were taken on 100 mm sections of steel bars which were subjected to a wide range of corrosion conditions, from passive steel to actively corroding steel. The duration of the applied galvanostatic pulse was varied between 5s and 180s, and the lateral distance of the point of measurement on the steel bar varied from zero to 400 mm. The result of the electrochemical transient response was investigated using a typical sampling rate of 1 kHz. Analysis of the transient potential response to the applied galvanostatic pulse has enabled the separation of equivalent electronic components so that the components of a series of capacitances and resistances, whose values are dependent on the corrosion condition of the reinforcing steel, could be isolated. The corrosion rate was calculated from a summation of the separate resistive components, which were associated with the corrosion interface, and was compared with the corrosion rate obtained from linear polarization resistance (LPR) method. The results show that the galvanostatic pulse transient technique enables the components of the polarization resistance to be evaluated separately so as to give more reliable corrosion rate values than those obtained from the LPR method. Additionally, this paper shows how the galvanostatic pulse transient response technique can be implemented. An appropriate measurement time for passive and actively corroding reinforcing steel is suggested for the galvanostatic pulse transient response measurements in the field site.

• 한국전자파학회논문지
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• 제7권4호
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• pp.300-309
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• 1996

뇌방전에 의해 방사되는 전계와 자계의 세기는 시변성으로 세기도 대단히 크게 변화하며, 최신의 전자기기에 관련한 전자계 양립성에 대한 과제 중의 하나가 직격뢰뿐만 아니라 근접뢰에 의해 발생하는 과도전압에 대한 효율적이고 경제적인 보호에 관한 것이다. 본 논문에서는 뇌전자계 임펼스파형에 관한 상세한 정보를 얻기 위해서 1995년의 여름에 발생한 뇌방전에 의해 방사된 전계와 자계를 고속전계센서와 루프형 자계센서로 측정한 파형과 이들의 특성을 분석한 결과를 기술 하였다. 전계와 자계의 신호는 12비트의 분해능과 5000포인트의 기억용량을 가지는 기록장치를 이용하여 200 ns 의 시간간격으로 생플링되어 연속적으로 기록하였다. 귀환뇌격시에 방사된 전계와 자계의 파형은 운내방전의 전계와 자계파형과는 매우 달랐다. SOkm이상의 거리 에서 발생한 운내뇌방전에 의해 방사된 자계파형은 전계파형과 거의 일치하였다. 또한 뇌방전에 의해 방사되는 전계와 자계의 주요 주파수 성분은 수 kHz에서 수백 kHz의 범위를 갖는 것으로 나타났다.

• 한국조경학회지
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• 제14권3호
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• pp.3-19
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• 1987

The purpose of this study was to investigate desirable width / height ratio of enclosed space and to offer basic information for the design of enclosed spaces. The data of this study were gathered from the experiment through simulation. Photographic sampling of 7 campus sites located in Kwanak campus of Seoul National University and slides of perspective drawings of enclosed spaces with various D/H ratio (12, 1, 2, 4, 6, 9, 12)were used for simulation. A response format was made using the method of paired comparison and students from various departments were randomly selected for evaluation. In the method of analysis of data Thurstone's equation of Comparative Judgement was used for calculating preference score. A1so non-linear regression analysis was used for finding out relations between preference and D/H ratio. The other method of data analysis were correlation, Chi - test. And the results were summarized as follows. 1. In sketch simulation the ratio of D/H 4 got the highest preference store. This result suggests that desirable D/H ratio of enclosed space is D/H 4. And at the lower range of D/H ratio, as ratio increases, the preference score increases. At the higher range of D/H ratio, however, as ratio increases, the preference score starts to decrease from the cardinal point of D/H 4. 2. In campus photograph simulation preference is influenced by slope, elevation change of floor, trees, lawn area, familiarity, space arrangement, and exterior shape of building besides D/H ratio. 3. The preference virtue was not significantly affected by order effect. This result suggests that order effect can be ignored in the study of visual preference. 4. There are so many factors related to preference that it is difficult to explore those factors without scientific information based on scientific method. We must carry out study for scientific approach of planning and design based on precise, complete simulation technique.

• 한국언론정보학보
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• 제43권
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• pp.81-113
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• 2008

이 연구의 목적은 비판언론학의 질적 연구방법론 적용사례를 분석함으로써 방법론적 성찰을 위한 기초 자료를 제시하는 데 있다. 이를 위해 우선, 비판언론학의 정체성 일부를 형성해온 언론학 패러다임 논쟁을 살펴보고, 이 논의를 기초로 질적 연구의 특성과 전통적 방법론의 유형에 대해 논의하였다. 나아가 한국 비판언론학을 주도해온 한국언론정보학회의 학술지에 게재된 학술논문들을 분석하여 질적 연구방법론 적용사례의 경향들을 분석하였다. 연구문제 해결을 위한 분석범주는 이론적 배경 및 방법론, 표본추출전략, 자료 수집방법, 자료 분석방법 그리고 신뢰성 검증 등 총 다섯 항목으로 구성하였다. 표본논문의 추출기간은 자료검색이 가능한 1998년도의 "한국언론정보학보" 제11권부터 최근 2007년 제40권까지로 설정하였고, 이 기간에 게재된 총 254편의 논문들 중에서 본 연구의 주제에 부합하는 논문들을 수집해 들어갔다. 논문의 수집방법은 키워드 검색기법을 사용하였다. 분석결과, 국내 비판언론학은 질적 연구방법을 적용함에 있어 보다 세부적이고 엄격한 방법론적 논의와 적용이 필요한 것으로 평가된다. 다양한 이론과 방법론을 적용하고 있지만, 방법론을 설계하고 결론을 도출함에 있어 세부적인 분석범주와 항목에 대한 구체적인 논의가 이루어지고 있지 않기 때문이다.

• 한국통신학회논문지
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• 제35권5C호
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• pp.439-444
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• 2010

본 논문에서는 대역확산 워터마킹 시스템을 무선채널 환경에서 부가데이터를 전송하기 위하여 적용할 경우 채널에 의한 영향을 분석하기 위하여 채널용량식을 정보이론적 관점에서 유도하고 분석한다. 부가데이터를 기존의 무선통신 시스템을 통하여 전송하기 위해서는 무선채널을 통과하는 워터마킹 신호가 채널에 의해서 어떻게 영향을 받고, 어느 정도의 데이터를 신뢰할 만한 수준으로 전송가능한지를 판단하는 기준으로서의 채널용량에 관한 연구가 필수적이다. 수치적 결과로부터 대역확산 워터마킹 시스템의 채널용량은 HWR, WNR, PN 길이 및 호스트 시스템의 샘플링 주파수에 의해 결정됨을 알 수 있었다. 또한 적용된 Nakagami-m 페이딩 채널과 Log-normal 새도잉 채널에서 채널 상태 변화에 따른 채널용량의 변화를 확인하였고 다이버시티를 적용했을 경우의 채널용량의 향상 또한 확인하였다. 본 논문에서 다룬 대역확산 워터마킹 시스템의 채널용량의 수식적 결과는 PN 시퀀스를 이용하는 일반적인 대역확산 워터마킹 시스템에 적용할 수 있다.

• 한국융합학회논문지
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• 제11권7호
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• pp.51-57
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• 2020

본 연구는 인간의 주관성 연구를 목적으로 하는 Q방법론을 적용하여 임상실습을 경험한 방사선과 학생의 방사선과 이미지에 대한 주관적 인식 유형과 그 유형의 특성을 살펴보고 이를 근거로 바람직한 방사선사의 이미지를 정립하기 위한 방사선과의 교육프로그램의 기초자료를 제공하고자 수행하였다. 8주동안 첫 임상실습을 경험한 3학년 방사선과 학생 30명을 P표본으로 편의표집 하였으며 33개의 Q표본을 9점 척도의 Q 분포도상에 강제 분포하도록 하였다. 수집된 자료는 QUANL PROGRAM에 의한 주인자분석법으로 처리하였다. 연구결과 아이겐 값(Eigen value)이 1.0이상으로 2개의 유형으로 분류되었다. 제 1유형은"환자중심형", 제 2유형은"조직중심형"이었다. 이 결과는 예비방사선사인 방사선과 학생의 직업가치관 유형별 향후 진로방향의 기초자료로 활용할 수 있다고 생각한다.

• ALGAE
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• 제31권1호
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• pp.33-39
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• 2016

Blooms of macroalgae have grown over the planet in recent decades as a possible result of eutrophication of coastal waters. Visually, a bloom forming can be identified by dominant presence of an organism at the expense of others. In mid-January 2014, a forming bloom of red algae was detected on the beach of Garopaba, Santa Catarina State, Brazil. This aroused the interest of tourists and locals as well as the scientific community. Thus, the objective of this study was to characterize and quantify the photosynthetic floating organisms contributing to this phenomenon. In addition, we qualitatively compared algal composition of the bloom to those deposited in the post-beach area and the adjacent rocky shore community. Five sampling points in random patches of floating material were defined. At each point, five replicates were taken with a cube of 32,768 cm³, resulting in a total of 25 samples. Samples were collected in the inner area enclosed by a PVC quadrate of about 900 cm² from the shore and the specimens found in post-beach zone (wrack). Twenty-four taxa of macroalgae were found in the bloom, with Aglaothamnion uruguayense as the dominance one. Ten taxa were found on shore. Only four taxa were found in the post-beach area. The biomass estimated for A. uruguayense in the floating material was 8.35 tons with an estimated area of 52,770 m² . It is possible that this huge biomass value of the bloom is related to the local nutrient intake, and our results reinforce the necessity of coastal integrative management initiatives.

• 대한기계학회논문집B
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• 제34권7호
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• pp.703-714
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• 2010

본 연구에서는 크리깅 기법을 이용하여 엇갈린 핀휜이 부착된 회전하는 내부냉각유로의 형상 최적화를 수행하였다. 냉각유로 형상의 여러 매개변수 중 핀의 지름과 높이의 비, 핀의 지름과 핀과 핀 사이의 거리의 비를 최적설계를 위한 설계변수로 선택하였다. 열전달 관련 목적함수와 마찰손실 관련 목적함수를 가중계수를 이용하여 선형적으로 결합한 목적함수를 정의하였다. 크리깅 모델을 구축하기 위해 라틴하이퍼큐브 샘플링기법에 의해 생성된 20개 실험점에서 목적함수가 SST난류모델을 사용한 삼차원 레이놀즈평균 나비어-스톡스(RANS) 유동해석법에 의해 계산되었다. 크리깅 기법을 통하여 예측된 목적함수값은 RANS해석을 이용해 계산된 값과 매우 작은 오차 범위 내에서 일치하였으며, 최적설계를 통해 목적함수가 11% 감소하는 결과를 얻었다.