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        검색결과 99

        61.
        2023.06 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the characteristics of Volatile Organic Compounds(VOCs) emission from painting and printing facilities in the Pyeongdong industrial complex in Gwangju. In addition, the objective was to understand the distribution characteristics of VOCs in the ambient air in industrial complexes affected by painting and printing facilities. The painting facility mainly emitted toluene, acetone, butyl acetate, 4-methyl-2-pentanone, ethyl acetate, 1-butanol, methyl ethyl ketone, m,p-xylene, o-xylene, 4-ethyltoluene, ethylbenzene, 3-ethyltoluene, and 1,2,4-trimethylbenzene. The main emission components in printing facilities were methyl ketone, ethyl acetate, acetone, 2-propanol, toluene, heptane, and butyl acetate. Ethyl acetate, toluene, 2-butanone, acetone, butyl acetate, 2-propanol, xylenes, and 4-methyl-2-pentanone were detected in the ambient air of the Pyeongdong industrial complex, consistent with the VOCs emitted by painting and printing facilities. The average concentration of seasonal TVOCs followed an order of winter > fall > spring > summer, whereas the concentrations of daytime and nighttime TVOCs were generally higher at night than those during the day, and the wind speed was greater during the day than it was at night. Based on a factor analysis of VOCs in the ambient air of Pyeongdong industrial complex, it is considered that organic solvents used in coating, printing, and electronics manufacturing facilities, as well as diesel vehicle emissions played a major role.
        62.
        2022.03 KCI 등재 서비스 종료(열람 제한)
        지구/행성 내부의 다양한 지질학적 과정을 이해하기 위해서는 고온-고압 환경에서 지구 내부 구성 물질의 특성을 이해하는 것이 필수적이다. 이러한 고압환경을 생성하기 위하여 사용되는 멀티 앤빌 프레스 (multi-anvil press)는 주로 상부맨틀조건의 극한 상황을 재현하는데 사용된다. 멀티 엔빌프레스의 지질학적 사 용을 위한 필수 보정 과정 중 하나는 압력을 생성하기 위한 프레스의 유압과 실제로 시료에 가해지는 압력 사이의 관계인 압력-부하 보정(pressure-load calibration)이다. 압력-부하 보정은 일반적으로 고온-고압 조건에 서는 결정질 물질의 상전이를 이용해서 이루어지는데, 고온에서의 경우와 달리 저온(상온)의 경우 상전이 과 정이 상대적으로 비효율적이므로 압력-부하 보정의 다른 방법론이 요구된다. 본 연구에서는 파이로프 조성 (Mg3Al2Si3O12)의 비정질(비정질 파이로프)의 상온에서의 압축(cold compression)에 따라 발생하는 영구적인 고 밀도화 현상(permanent densification)과 그 기원이 되는 알루미늄 배위 환경의 변화를 고해상도의 27Al MAS 및 3QMAS NMR 분광분석을 통해 정량화하고, 이로부터 압력에 따른 알루미늄의 배위수 변화를 이용해 14/ 8 HT 조립세트(assembly set)와 1,100톤 멀티 앤빌 프레스에 대한 상온에서의 압력-부하 보정을 수행하였다. 본 연구는 NMR분광분석을 이용하여 압력보정을 수행한 최초의 연구결과이며, 비정질 파이로프의 압축-감압에 따른 원자 단위에서의 비가역적 구조 변화는 섭입대 환경과 같은 저온 고압 환경에서 비정질 물질이 겪는 변 화와 그에 따른 지질학적 현상의 이해고양에 실마리를 제공한다.
        63.
        2022.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        It is suggested that magnetosonic waves (also known as equatorial noise) can scatter radiation belt electrons in the Earth’s magnetosphere. Therefore, it is important to understand the global distribution of these waves between the proton cyclotron frequency and the lower hybrid resonance frequency. In this study, we developed an empirical model for estimating the global distribution of magnetosonic wave amplitudes and wave normal angles. The model is based on the entire mission period (approximately 2012–2019) of observations of Van Allen Probes A and B as a function of the distance from the Earth (denoted by L*), magnetic local time (MLT), magnetic latitude (λ), and geomagnetic activity (denoted by the Kp index). In previous studies the wave distribution inside and outside the plasmasphere were separately investigated and modeled. Our model, on the other hand, identifies the wave distribution along with the ambient plasma environment—defined by the ratio of the plasma frequency (fpe) to the electron cyclotron frequency (fce)—without separately determining the wave distribution according to the plasmapause location. The model results show that, as Kp increases, the dayside wave amplitude in the equatorial region intensifies. It thereby propagates the intense region towards the wider MLT and inward to L* < 4. In contrast, the fpe/fce ratio decreases with increasing Kp for all regions. Nevertheless, the decreasing aspect differs between regions above and below L* = 4. This finding implies that the particle energy and pitch angle that magnetosonic waves can effectively scatter vary depending on the locations and geomagnetic activity. Our model agrees with the statistically observed wave distribution and ambient plasma environment with a coefficient of determination of > 0.9. The model is valid in all MLTs, 2 ≤ L* < 6, |λ| < 20°, and Kp ≤ 6.
        64.
        2020.05 KCI 등재 서비스 종료(열람 제한)
        This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM2.5 and PM10 were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM2.5 and PM10, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM2.5 and from 45.1% to 29.1% in PM10, despite the exclusion of organic matter and elemental carbon.
        65.
        2020.03 KCI 등재 서비스 종료(열람 제한)
        서울시는 국내 광역자치단체 최초로 도시마케팅 개념을 도입하여 ‘I Seoul You’라는 도시 브랜드를 개발하였다. 이 브랜드는 세계에서도 유례를 찾아 보기 힘든 방법으로 브랜드를 개발하였다. 그것은 바로 시민 주도형 브랜드 개발이다. 이는 오픈 소스 비즈니스 전략을 활용한 것으로 관 주도의 일방적 활용이 아닌 시민 자발을 활용하는 것을 말한다. 세계적으로 도시 브랜드를 활성화하여 관광객을 유치하는 나라의 경우, 세계를 상대로 투자 유치를 이끌어 내고 있다. 이는 도시 브랜드가 지닌 힘이다. 서울시도 새롭게 도약하려면 도시 브랜드를 창출 할 필요성이 절실해졌다. 이를 통해 시민 대표와 위원회 위원 간 의견 공유의 기회를 마련하는 취지에 대해서는 동의하나 시민회의에서 위원들의 역할을 명확하게 할 필요가 있다. 따라서 본 연구는 시민주도형 브랜드 개발의 활용사례와 그에 따른 효과를 조사하고 서울시 관광을 활성화하기 위해 시민 참여형 엠비언트 광고를 10가지 제안한다. 시민들의 반응도를 조사해 보았으며 설문조사의 79%이상이 앰비언트광고가 기존 광고보다 긍정적이라는 의견을 보였다. 이에 본 연구를 통해 앰비언트를 적극적으로 활용하여 시민참여형 광고를 활성화 할 필요가 있다고 본다.
        66.
        2019.10 서비스 종료(열람 제한)
        This paper presents the results of the tests on electrical impedance for the steel wire under the effect of ambient temperature and stress level shift. The experiments are carried out in variable temperature conditions ranging from 30 to 60 ℃ and different stress levels ranging from 10% to 70% of yield strength. The results show the relationship between electrical impedance and temperature is a linear correlation at all stress levels.
        67.
        2019.10 서비스 종료(열람 제한)
        본 연구에서는 외기온 영하조건에서 노출시간 변화별 콘크리트의 초기동해 피해를 입는 온도이력을 확인하고, 실험연구결과 –10℃인 외기조건에서 200 mm 두께의 슬래브는 18시간까지는 외기온에 노출되어도 콘크리트의 수화열에 의해 초기동해 피해가 발생하지 않는 것을 알 수 있었다.
        68.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        본 논문은 초음파 검사 및 판독에 사용되는 CRT, LCD 모니터에서 영상검사와 판독 시 적절한 시각화에 대한 최적의 주변 조도 수준을 제안하고자 하였다. 평가자들은 4그룹 20명(Ultra-sonographer 20명(4 groups; ultra-sonographer 1~5 years 5명, ultra-sonographer 6~10 years 5명, ultra-sonographer 11~15 years 5명, ultra-sono grapher 16~20 years 5명)을 대상으로 하였으며, 문항수는 32문항이었다. 평가방법은 10, 25, 100 Lux 3가지 주변광 조도에서 초음파 soft copy 영상을 1문항 당 30초간 영상 평가하였으며, 평가 결과를 6점 척도로 1 점=Normal (Definitely no lesion), 2점=possibly not a lesion, 3점=probably not a lesion, 4점=possibly a lesion, 5 점=probably a lesion, 6점=Definitely a lesion으로 나타내었다. 본 연구에서 주변광에 따른 초음파 영상들에 대한 병변 감지에 사용되는 소프트 카피(soft copy) 영상 판독 ROC분석 결과는 10 Lux에서 높은 민감도, 특이도, 곡선하면적 결과를 나타내었다. 주변광 조도로 10 Lux를 이용한다면 초음파(ultrasound) 소프트 카피(s oft copy) 영상의 병변 탐지에 있어 최적의 효과를 얻을 수 있음을 알 수 있었다. 추후 연구 자료를 기초로 하여 초음파 영상 검사실 및 판독실의 주변광 조명밝기를 설계하면서 기초자료로 제시될 것으로 생각한다.
        69.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        Purpose - Present research aimed at identifying the effects of ambient pride type on judgement difference between existing preference and final preference formed after being exposed to the preference inconsistent information from others representing a conflict between consumer’s own perspective and the others’ perspective. And this study also explored the roles of empathic concerns and motive type in the ambient pride type’s effects on the judgement difference. Research design, data, and methodology - 2(information type: consistent versus inconsistent) × 2(pride type: hubristic versus authentic) between-subjects design was employed. Data for empirical analysis were from 252 undergraduate students who participated in questionnaire survey. To verify hypotheses, Anova and regression analysis were used. Results - First, there was the judgement difference among the experimental groups. The difference was greater at the authentic pride group than at the hubristic pride group. And the difference was greater at the inconsistent information group than at the consistent information group. The interaction effect of pride type and information type was significant. Second, when consumers who had made their preference were exposed to the inconsistent information from other, those of the hubristic pride group showed more defense motive and less empathic concerns than those of the authentic pride group. And there were the mediation roles of the empathic concerns and the interaction roles of the motive type in the effects of pride type on the judgement difference. Third, the self validity did not affect the difference even that become increased by defense motive rather than accuracy motive. Conclusions - This research could advance the information processing theory related to pride type by exploring the effects of the pride type on judgement difference between existing preference and final preference formed by the inconsistent information from others, and by identifying the mediation roles of the empathic concerns and the interaction roles of the motive type in the effects of the pride type. In view of the results from current study, marketers should make efforts of inducing defense motive and developing and communicating the consistent information to persuade consumers under hubristic pride who have the belief that attributes of their brand are better than those of the competitors’ brand, and they also should conduct marketing acts by using the inconsistent information to persuade consumers under authentic pride who have the belief that attributes of the competitors’ brand are better than those of their brand.
        70.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        Background: Small particles increase airway inflammation upon reaching the alveoli. Here, we investigated the protective or therapeutic effects of Salvia plebeia R. Br. (SP_R) extracts on airway inflammation. Methods and Results: To investigate the anti-inflammatory activity of SP_R extracts, we measured their inhibitory effect on the production of reactive oxygen species (ROS) expression of inflammatory mediators, and immune cell infiltration in MH-S alveolar macrophage cells and in the ambient particulate matter (APM)-exposed airway inflammation mice model. The SP_R extracts inhibited the production of ROS and expression of IL-4, IL-10, IL-15, and IL-17A mRNA in APM-stimulated MH-S cells. Oral administration of SP_R extracts suppressed APM-induced inflammatory symptoms, such as high alveolar wall thickness, excess collagen fibers, decreased mRNA expression of chemokines (Ccr9, Ccl5, Ccr3), inflammatory cytokines (IL-15, TNF-α), and IL-4 Th2 cytokine in the lung. The SP_R extracts also inhibited ROS production, granulocyte (CD11b+Gr-1+) infiltration, IL-17A, TNF-α, macrophage inflammatory protein (Mip-2), and chemokine (C-X-C motif) ligand 1 (Cxcl-1) production in the airway. The specific compounds in the SR-R extracts that mediate the anti-inflammatory effects were identified. Conclusions: In this study, SP_R extracts effectively inhibited airway inflammatory responses, such as ROS production and granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines.
        71.
        2017.04 서비스 종료(열람 제한)
        This research aim to investigate the qualitative and quantitative performance of concrete deteriorations using Pulse Square Thermography (PST) technique. An experimental test of ten cases was conducted on a concrete slab specimen under different meteorological conditions. The results showed that the absolute contrast between defective area and sound area decreases with the falling of ambient temperature. Besides, the delamination with identical size but placed at a deeper position indicates lower absolute contrast than the shallow delamination.
        72.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        Concentrations of fine particulate matter (PM2.5) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. PM2.5 mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the PM2.5 constituents' regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven PM2.5 constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the PM2.5 constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to PM2.5 mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.
        73.
        2016.04 서비스 종료(열람 제한)
        High speed railway bridges should be strictly maintained due to its social importance. However, There are many problems to execute loading test for precision safety diagnosis. A numerical experiment with a numerical model which is updated for reflecting characteristics of an existing bridge can be useful for high speed railway bridge maintenance. Moreover, more efficient maintenance can be possible if only ambient vibration is needed for numerical model updating process. In this study, a numerical model updating process is introduced in which only ambient vibration is enough to execute the process. Also, the usability of updated numerical model is verified by comparing measured and analyzed acceleration.
        74.
        2015.07 KCI 등재 서비스 종료(열람 제한)
        In 2013, International Agency for Research on Cancer (IARC) concluded that outdoor air pollution is carcinogenic to humans, with the particulate matter component of air pollution most closely associated with sufficient evidence of increased cancer incidence by exposure to particulate matter component of air pollution. Motor vehicles are one of a major emission sources of fine particle (PM2.5) in urban areas. A large number of epidemiological studies have reported a positive association of morbidity or mortality with distance from the roadside. We conducted this study to assess the association of PM2.5 concentrations measured at roadside hotspots with those at adjacent residential sites using real-time PM2.5 monitors. We conducted real-time PM2.5 measurements for rush hour periods (08:00∼10:00 and 18:00∼20:00) at 9 roadside air monitoring Hotspot sites in metropolitan Seoul over 3 weeks from October 1 to 21, 2013. Simultaneous measurements were conducted in residential sites within a 100 m radius from each roadside air monitoring site. A SidePak AM510 was used for the real-time PM2.5 measurements. Medians of roadside PM2.5 concentrations ranged from 9.8 μg/m3 to 38.3 μg/m3, while corresponding median values at adjacent residential sites ranged from 4.4 μg/m3 to 37.3 μg/m3. PM2.5 concentrations of residential sites were 0.97 times of hotspot roadside sites. Distributions of PM2.5 concentrations in roadside and residential areas were also very similar. Real-time PM2.5 concentrations at residential sites, (100 m adjacent), showed similar levels to those at roadside sites. Increasing the distance between roadside and residential sites, if needed, should be considered to protect urban resident populations from PM2.5 emitted by traffic related sources.
        75.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        소비자는 보다 참신하고 기발한 아이디어의 광고를 원하고 있다. 최근 주변환경을 활용한 앰비언트 광고가 각광을 받고 있는데 이에 주변환경을 활용한 광고에서 나타나는 착시 효과의 요소들을 추출하여 소비자에게 도움이 되는 광고를 제작하는데 도움을 주고자 하였다. 그 결과 겹침의 착시, 반전의 착시, 깊이의 착시, 유사성의 착시로 총 4가지의 요인으로 추출되었다. 첫째 겹침의 착시는 두 가지의 매체가 거리나 시간에 따라 달라 보이는 착시효과며, 다음으로 대비기법으로 하나의 이미지가 두 개의 메시지를 전달하는 착시효과로 지면광고에서 주로 사용되어 단순 기법이라 할 수 있다. 그리고 깊이에 의한 착시로 형태가 다른 형태를 차단하는 두 개의 도형사이에는 공간이 생기고 각기 다른 평면인 것처럼 속이는 착시효과를 말하며, 형태, 지각, 행동의 유사성에 의해 하나의 매체가 두 가지의 메세지를 전달하는 착시효과 가장 광고인들이 선호하는 착시 기법 중 하나라고 할 수 있다. 이 앰비언트 광고 제작시 보다 유용한 자료로 활용되었으면 하는 바램이다.
        76.
        2014.10 서비스 종료(열람 제한)
        This study presents a damage detection method for shear-building structure based on the change of diagonal terms of a modal flexibility matrix. Numerical simulation and experimental validation were conducted on a 5-story shear-building structure. The proposed damage detection method showed accurate and suitable results.
        77.
        2014.10 서비스 종료(열람 제한)
        In this paper, it proceed the fascinating experimental study to use the system identification(SI) for a long time measurement. The aim of the study is to identify the dynamic characteristics using the SI based on ambient vibration(AV) tests for monitoring systems at building structures. White noise, which is naturally occurring for harmonic components, and free vibration tests are employed in obtaining output data. A definite answer of the dynamic characteristics manages to extract from the frequency domain decomposition(FDD) method under the condition of the white noise. The singular value of the following test is used by FDD. These results show the validity of AV test and the usability of FDD in comparison with two tests. The result of the study is to design practical criteria for SI for building structures based on AV tests.
        78.
        2013.10 서비스 종료(열람 제한)
        This study is a result of the dynamic characteristics of tall building located in Haewoondae. In order to analyze the natural frequency and damping ratio of the building, acceleration is measured through wind monitoring system during 6 months.
        79.
        2013.10 서비스 종료(열람 제한)
        Structural damping includes material damping, friction effects at bearing and expansion joints, friction at bolted joints and mechanical damping by damper. There is not analytical basis for estimating the damping ratios. Structural damping ratios can be estimated by measuring forced vibration amplitude of a certain mode but it is almost impossible to vibrate the actual bridges to a certain mode by force. Therefore, RD technique utilizing a lot of ambient vibration data can be a practical method to estimate damping ratio. In this study, the damping ratio is estimated by analyzing the ambient vibration data of three steel cable stayed bridges.
        80.
        2012.07 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 미국 뉴욕주 로체스터시 소재 강합성 데크 트러스 보도교를 대상으로 사용성을 평가하기 위한 상시진동 실험(ambient vibration test)을 수행하였고 이를 해석적 방법에 의한 결과와 비교하였다. 교량전체에 대한 상시진동실험은 수치모델 작성 시 도입되는 여러 가정들에 대한 타당성을 평가하는데 있어서 유용한 방법이며, 교량의 고유진동수나 모드형상과 같이 구조 동력학에서 중요한 구조적인 변수를 결정하는데 있어 중요한 역할을 한다. 본 연구에서는 교량의 수직방향 및 수평방향 진동 특성과 변위를 측정하기 위하여 실제 교량에서 보행자에 의해 발생하는 진동을 입력하중으로 사용하였다. 교량 구조물에 대한 모델링을 위하여 3차원 유한 요소법을 사용하여 해석을 수행하였으며, 이를 통하여 현장실험 결과와의 유효성을 입증하였다.
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