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        검색결과 357

        42.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Subway trains with air cleaners have been newly deployed in the Seoul Metro system. The purpose of this study was to determine differences regarding in-cabin particulate matter with respect to concentrations less than 10 um (PM10) and 2.5 um (PM2.5) through the operation of air cleaners in subway trains. One subway train newly installed with in-cabin air cleaners on Seoul Metro Line number 2 was chosen monitoring in 2020. In-cabin air cleaners were turned-on at both front and back areas while those in the middle area were turned-off while the train was running. In-cabin PM10 and PM2.5 concentrations were measured in each area using a real-time aerosol monitor. Average in-cabin PM10 concentrations were statistically significantly lower (by 15%) in areas with air cleaners turned-on (43.8±12.1 μg/m3) compared to those areas where the air cleaners were turned-off (51.4±15.0 μg/m3). Average incabin PM2.5 concentrations were significantly lower (by 14%) in areas with air cleaners turned on (33.7±12.2 μg/m3) compared to those areas where air cleaners were turned-off (39.2± 14.4 μg/m3). In-cabin PM10 and PM2.5 concentrations ratios were similar regardless of area with air cleaners turned-on or turned-off. The in-cabin PM10 and PM2.5 concentrations were not associated with commute time. Use of air cleaners in subway trains effected reductions in in-cabin PM10 and PM2.5 concentrations.
        4,000원
        43.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 코로나-19(COVID-19)로 인해 원격근무의 중요성이 강조되고 있는 상황에서 본 연구는 원격근무 상황에서 자기효능감의 역할에 대해 살펴보았다. Bandura(1986)의 자기효능감에 영향을 주는 4대 요인과 Staples et al.(1999)의 가상조직 기반에서의 자기효능감의 선행요인에 관한 연구를 활용하여 연구모형을 설정하였으며, 자기효능감의 선행 변수로는 원격근무에 대한 직접경험, 상사의 원격근무 관찰 경험, IT 변화 두려움, 상사의 코칭을 설정하였다. 또한, 상사의 코칭을 통한 언어적 설득이 자기효능감에 영향을 주는 과정에서 상사 신뢰의 조절효과에 대하여 검증을 하고자 하였다. 본 연구의 목적을 달성하기 위하여 원격근무 경험이 있는 근로자 463명의 설문응답 결과를 분석 자료로 활용하였다. 연구 결과는 원격근무에 대한 직접경험과 상사의 코칭을 통한 언어적 설득은 자기효능감을 높이는 정(+)의 영향을, IT 변화 두려움은 자기효능감을 낮추는 부(-)의 영향을 미치는 것을 확인하였다. 그리고 상사 신뢰가 높은 집단은 상사 신뢰가 낮은 집단에 비하여 상사의 코칭이 자기효능감에 미치는 효과가 더 강한 것으로 확인되었다. 본 연구는 4차 산업 환경과 코로나-19의 시대적 상황을 반영한 원격근무와 자기효능감에 대한 연구를 통하여 원격근무에 대한 직접 경험이 자기효능감에 영향을 주는 주요한 변수임을 확인하였다.
        6,700원
        44.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chinese Idioms are important as a Part of Chinese Vocabulary, Korean learners who use Chinese as a second language understand and grasp the usage of the Chinese-Korean idiom,It will also play a significant role in learning Chinese for Korean learners. A Comparative Study on Chinese and Korean idiom of same patterns of synonyms provides many conveniences and references for Korean Chinese learners, Nevertheless, there are differences in Chinese and Korean of syntactic, semantic and pragmatic functions of idiom of same patterns of synonyms. Therefore, Korean Chinese learners may have some troubles learning and using Chinese idioms. Dissertation takes between Chinese and Korean idiom of same patterns of synonyms from the new HSK level six Vocabulary Outline and two sets of the new HSK level six official test paper as the research subject, make Research and Analysis on Chinese and Korean synonym idioms differences between using frequency and usage of idioms in Chinese and Korean databases, in addition, make a comparative study between Chinese and Korean of syntactic and pragmatic functions of idiom of same patterns of synonyms, both Chinese and Korean idiom of same patterns of synonyms of the meanings are similar, however there are still many differences.
        5,200원
        45.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        화석 연료를 사용할 때, 불완전 연소는 필연적으로 발생하는 문제이다. 이러한 관점에서 연소 후 기체 분리는 불완전 연소 기체의 재활용 가능성을 시사한다. 이와 관련하여 본 연구에서는 일산화탄소 기체 분리용 촉진수송 고분자 분리막을 제조하였다. 이를 위해 poly(vinyl alcohol) (PVA) 주사슬 기반으로 acrylic acid (AA) 단량체를 자유 라디칼 중합법으로 PVA-g-PAA 공중합체를 제조하였다. 본 공중합체를 일산화탄소 활용에 적용하는 사례는 처음이며, 제조한 공중합체는 AgBF4 염과 HBF4를 혼합하여 기체 분리막에 적용하였다. 공중합체 합성 결과는 FT-IR을 통해 분석하였으며, 공중합체와 AgBF4, HBF4의 상호작용은 TEM를 통해 분석하였다. 염의 첨가를 통해 일산화탄소 기체의 촉진수송 채널을 형성하였으며 이를 통해 일산화탄소 분리막 분야에 촉진수송 및 그래프팅 방법이라는 새로운 접근법을 제시하였다.
        4,000원
        52.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Based on corpus linguistics, synchronic and diachronic linguistics, lexicology, pragmatics, sociolinguistics and other theoretical knowledge, this paper makes a dynamic and in-depth study of the “Gou” popular neologisms. Under the guidance of corpus linguistics, this paper makes a statistical analysis of the word family of “Gou”, summarizes the growth of the number of members of the word group, the high frequency use of the word family, the syllable structure of the members of the word family, etc., and shows the changing characteristics of the word group in various aspects. Using the methods of etymology investigation and dynamic tracking, this paper analyzes that the word family of “dog” is a process in which many new words of “xxgou” type are derived from the original use of “single dog”, and gradually expand to 128 members. Under the guidance of lexicology theory, by means of semantic analysis, this paper sums up four referential meanings of "Gou" from the referential meaning of [+ animal] to [+ human], and then, through generalization, it derives four referential meanings of [+ identity], [+ profession / profession / field], [+ state], [+ stress / tension], [+ preference], [+ behavior / thing], [+ aversion], [+ behavior / thing]. Under the guidance of pragmatics theory, this paper explores the word family of “Gou” and summarizes the characteristics of the morpheme “Gou” of the family of words with the characteristics of quasi affixation, trisyllabic structure of words and single part of speech of members of the word group.
        4,500원
        53.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, actual odor conditions were investigated in restaurants, livestock facilities, and major odor discharge facilities around daily life, and an odor modeling program was performed to find ways to improve odors in odor discharge facilities. The odor modeling results of restaurants around daily life showed that the complex odor concentration of large restaurants, which are close to residential areas, is higher than the acceptable complex odor standard at the receiving point. It was judged that a plan to increase the height of the restaurant odor outlets and a plan to reduce the amount of odor discharge was necessary. As a result of modeling the life odor of livestock housing facilities, when the distance from the housing facility is far away, the actual emission concentration is much lower than the acceptable emission concentration at the receiving point. It was judged that such facilities need to be reviewed for ways to reduce the emission of odorous substances, such as sealing the livestock housing facilities or improving the livestock environment. The main odor emission business sites that show complex odor concentration as 1,000 times or greater than the outlet odor emission standard were businesses associated with surfactant preparation, compounded feed manufacturing, textile dyeing processing, and waste disposal. Due to the separation distance and high exhaust gas flow rate, it was found that odor reduction measures are necessary. In this study, it was possible to present the allowable odor emission concentration at the discharge facilities such as restaurants, livestock houses, and industrial emission facilities by performing the process of verifying the discharge concentration of the actual discharge facility and the result of living odor modeling. It is believed that suitable odor management and prevention facilities can be operated.
        4,200원
        55.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        과수농가에서 수행되는 수확작업은 노동부하가 큰 주요작업으로 수확된 과실의 적재 및 운반작업에 소모되는 노동력이 크다. 본 연구에서는 과수농가를 대상으로 수확된 열매의 적재 및 운반작업에 사용 가능한 간이형 보행 동력운반차를 개발하였다. 과수 농민들의 요구조건을 고려하여 동력운반차의 이동속도 및 적재 용량을 선정하였다. 이에 따라, 동력운반차의 주요 구성요소를 선정하고 동력전달경로를 분석하였다. 또한, 개발된 동력운반차의 성능시험을 수행하였으며 상용 소프트웨어를 활용하여 구조해석을 수행하였다. 설계된 간이형 보행 동력운반차는 전·후진이 가능하고 이동속도는 최대 1 m/s이며, 최대적재용량은 500 kg이다. 본 연구에서 개발된 간이형 보행 동력운반차를 활용하면 농민들의 작업효율을 높이고 신체적인 부담을 경감시킬 수 있을 것으로 판단된다.
        4,000원
        57.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        MDPS control has been a difficult problem for the past two decades. Though there are many ways to control steering feeling, the MDPS control logic is still being upgraded or developed for steering feel improvement. A new point of view in MDPS is proposed by evolution logic, which is a new driver friendly improvement based on the analysis of driver’s driving pattern. As a result of the application of evolution logic, this paper shows that drivers behaviour effecting factors among MDPS parameters will efficiently lead to customers’ satisfaction.
        4,000원
        58.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 주요 수계 중 만경강, 섬진강, 남해권 수계, 탐진강, 영산강, 동진강과 연결된 농수로 어류의 종 조성과 어류 길드 특성, 군집 특성을 분석하였다. 2017년 9월부터 2018년 8월까지 4회에 걸쳐 현지 조사를 시행한 결과, 어류는 농수로에서 6목 11과 53종 3,633개체가 출현하였고 본류에서 9목 15과 57종 7,108개체가 출현했다. 농수로의 우점종과 아우점종은 칼납자루 (Tanakia koreensis)와 납자루 (T. lanceolata)로 나타났으며, 납자루아과의 어종이 우점하는 지점이 10지점 중 6지점으로 나타났다. 이는 담수성 이매패류의 서식에 기인한다고 사료된다. 그리고 환경부 지정 멸종위기 야생생물 I급 임실납자루 (T. somjinensis)가 섬진강 수계의 농수로에서 출현했고, 멸종위기 야생생물 II급 큰줄납자루 (Acheilognathus majusculus)와 꺽저기 (Coreoperca kawamebari)가 각각 섬진강 수계, 섬진강과 탐진강 수계의 농수로에서 출현했다. 지점별로 어류 길드 분석 결과, 대체로 농수로가 본류보다 낮은 민감종의 비율을 나타냈다. 군집 분석 결과 하상 구조가 복잡하게 나타난 지점에서 비교적 안정적인 군집을 보였으며, 환경적 변수에 따른 분석 결과 하상 구조가 복잡한 농수로 그룹이 높은 다양도 지수와 낮은 우점도 지수를 나타냈다. 결과적으로 본 연구는 농수로의 어류 서식 특성을 나타내고, 향후 연구와 관리의 필요성을 제시했다.
        4,600원
        59.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, real-time monitoring of air quality using a real-time mobile monitoring system was conducted to identify the emission characteristics and current status of air pollutants and odorous substances that are mainly generated in domestic dyeing industrial areas and to trace the pollutant sources. The concentration of toluene in the industrial area was detected up to 926.4 ppb, which was 3 to 4 times higher than that of other industrial areas. The concentration of methylethylketone was 124.7 ppb and the concentration of dichloromethane was 129.5 ppb. Acrolein concentration was highest at E point at 521.6 ppb, methanol concentration was highest at D point at 208.8 ppb, and acetone concentration was highest at M and N points at 549.3 ppb. The most frequently detected concentration of pollutants in the air quality monitoring results in the industrial area was, in descending order, toluene > methanol > acrolein > dichloromethane > acetone, which was similar to the chemical emissions used in the industrial area by the Pollutant Release and Transfer Register data. The concentration of odorous substances measured in real time was compared with the concentration of minimum detection, and the concentration of hydrogen sulfide was about 10 times higher than the concentration of minimum detection at A point, which was judged to be the main odorous cause of A point. In the future, if the real-time mobile measurement system is constructed to automatically connect wind direction/wind speed, PRTR (Pollutant Release and Transfer Register) data and SEMS (Stack Emission Management System) data, etc., it was judged that more accurate monitoring could be performed.
        4,000원
        60.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Reliability analysis of the components frequently starts with the data that manufacturer provides. If enough failure data are collected from the field operations, the reliability should be recomputed and updated on the basis of the field failure data. However, when the failure time record for a component contains only a few observations, all statistical methodologies are limited. In this case, where the failure records for multiple number of identical components are available, a valid alternative is combining all the data from each component into one data set with enough sample size and utilizing the useful information in the censored data. The ROK Navy has been operating multiple Patrol Killer Guided missiles (PKGs) for several years. The Korea Multi-Function Control Console (KMFCC) is one of key components in PKG combat system. The maintenance record for the KMFCC contains less than ten failure observations and a censored datum. This paper proposes a Bayesian approach with a Dirichlet mixture model to estimate failure time density for KMFCC. Trends test for each component record indicated that null hypothesis, that failure occurrence is renewal process, is not rejected. Since the KMFCCs have been functioning under different operating environment, the failure time distribution may be a composition of a number of unknown distributions, i.e. a mixture distribution, rather than a single distribution. The Dirichlet mixture model was coded as probabilistic programming in Python using PyMC3. Then Markov Chain Monte Carlo (MCMC) sampling technique employed in PyMC3 probabilistically estimated the parameters’ posterior distribution through the Dirichlet mixture model. The simulation results revealed that the mixture models provide superior fits to the combined data set over single models.
        4,000원
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