• 제목/요약/키워드: Relative dependence

검색결과 241건 처리시간 0.028초

상대습도계의 온도 의존성과 경년변화의 통계적 분석 (Statistical Analysis on the Temperature Dependence and Long-Term Change of Relative Humidity Sensors)

  • 김종철;최병일;우상봉;양인석
    • 센서학회지
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    • 제21권6호
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    • pp.420-424
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    • 2012
  • We have investigated temperature dependence and long-term change of humidity measurement from 32 relative humidity sensors. The readings of the humidity sensors depended not only the reference humidity, but also temperature of the chamber. Approximately, the temperature dependence of the humidity sensor in average was 0.05 %R.H./$^{\circ}C$ in the temperature range from $5^{\circ}C$ to $55^{\circ}C$. For humidity sensors that have an internal temperature compensation circuit, the resulting temperature dependence was weaker by 20%. It should be also noted that for the humidity sensors used in this work underwent ${\pm}3$ %R.H. change per year for level of confidence of 95%. The users of relative humidity sensors may refer this value as a minimum change when they set the calibration interval of the humidity sensors.

영상의학과에서 사용되는 광자극 형광선량계와 전자식 개인선량계의 방향 의존성 비교 (The comparison of angular dependence for optical stimulated luminescence dosimeter(OSLD) and electronic personal dosimeter(EPD) used in Diagnostic Radiology)

  • 권순무;박정규;김부순
    • 디지털콘텐츠학회 논문지
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    • 제16권3호
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    • pp.463-470
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    • 2015
  • 최근 개인선량계로 사용이 증가하고 있는 수동형 선량계인 OSLD와 능동형 선량계인 EPD의 상대 반응도(relative response), 측정 불확도(uncertainty of measurement)를 계산하여 방향의존성(angular dependence)을 비교, 분석하였다. OSLD는 수평, 수직방향의 $0^{\circ}{\sim}{\pm}90^{\circ}$ 범위에서 평균 상대 반응도는 0.97, 0.95의 작은 변화를 보였고 방향의존성에 대한 불확도는 0.65, 0.62로 전체 불확도에 미치는 영향은 미미한 것으로 판단되었다. EPD는 $0^{\circ}{\sim}{\pm}60^{\circ}$ 범위에서 수평, 수직방향 평균 상대 반응도는 0.94, 0.97로 확인되어 IEC 61526 규정을 만족하였다. 방향의존성에 대한 불확도는 수평, 수직방향에서 0.44, 0.40로 전체 불확도에 미치는 영향은 미미하였다. 그러나 수평방향에서 $+90^{\circ}$, $-90^{\circ}$ 방향의 상대 반응도는 0.60, 0.37이고 수직방향에서 $+90^{\circ}$ 방향의 반응도는 0.06으로 반응도의 큰 변화를 관찰할 수 있었다. OSLD의 방향 의존성은 $0^{\circ}{\sim}{\pm}90^{\circ}$ 범위까지 EPD에 비해 우수하였으며 EPD의 경우 구조적 특징으로 반응도가 급변하는 특정방향이 존재하였다. 따라서 수동형선량계와 보조선량계의 병행사용이 개인피폭선량측정의 정확도를 기할 수 있을 것으로 판단된다.

아시아 국가들 환경오염배출량의 확률수렴성과 환경쿠즈네츠곡선가설 검정 (The Test of Stochastic Convergence of Environment Emission and Environmental Kuznets Curve Hypothesis in Asian Developing Countries)

  • 김지욱
    • 자원ㆍ환경경제연구
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    • 제19권3호
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    • pp.571-595
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    • 2010
  • 본 연구는 1971년~2007년까지 아시아 11개국에 대한 일인당 상대(relative per capita) $CO_2$배출량의 확률적 수렴성(stochastic convergence)을 검정하고 일인당 상대 GDP와의 환경쿠즈네츠곡선(Environmental Kuznets Curve: EKC)가설을 검정하고자 하였다. 본 분석을 위하여 다중의 내생적 구조변화(multiple structural breaks)를 허용하고 횡단면 주체간 의존성(cross-sectional dependence)을 고려하는 Carrion-i-Silvestre et al. (2005)의 패널정상성검정(panel stationarity test)과 Banerjee and Carrion-i-Silvestre (2006)과 Westerlund and Edgerton (2007)의 패널공적분(panel cointegration) 검정 방법 등을 사용하였다. 분석 결과 아시아 국가들에서의 일인당 상대 $CO_2$배출량에서 장기 그룹평균 수준으로 확률적 수렴이 이루어지고 있었고 일인당 상대 GDP와의 사이에 공적분관계가 성립하였지만 EKC 가설의 존재를 발견하지 못하였다. 경제성장 발전에 우선적으로 정책을 집행하고 있는 아시아 국가에서는 오염배출량 감소보다 증가하는 국가들의 영향력이 크게 나타나 EKC 가설이 성립하지 않는 것으로 나타났다.

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Efficient Dynamic Object-Oriented Program Slicing

  • Park, Soon-Hyung;Park, Man-Gon
    • 한국멀티미디어학회논문지
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    • 제6권4호
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    • pp.736-745
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    • 2003
  • Traditional slicing techniques make slices through dependence graphs. They also improve the accuracy of slices. However, traditional slicing techniques require many vertices and edges in order to express a data communication link because they are based on static slicing techniques. Therefore the graph becomes very complicated, and size of the slices is larger. We propose the representation of a dynamic object-oriented program dependence graph so as to process the slicing of object-oriented programs that is composed of related programs in order to process certain jobs. We also propose an efficient slicing algorithm using the relations of relative tables in order to compute dynamic slices of object-oriented programs. Consequently, the efficiency of the proposed efficient dynamic object-oriented program dependence graph technique is also compared with the dependence graph techniques discussed previously As a result, this is certifying that an efficient dynamic object-oriented program dependence graph is more efficient in comparison with the traditional object-oriented dependence graphs and dynamic object-oriented program dependence graph.

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군사용 방사선 계측기 PDR-1K 반응도 평가 : 방향 및 에너지 의존성을 중심으로 (Evaluation for Performance of a Military Radiation Detecter PDR-1K : Focused on Dependence of Angular and Energy)

  • 박원석;최준혁;정도영;김장오;민병인
    • 한국군사과학기술학회지
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    • 제20권2호
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    • pp.300-305
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    • 2017
  • In this paper, we performed a evaluation for angular and energy dependence of military radiation detector PDR-1K. Its measuring range is divided into two section, low and high, and each range has a GM tube separately owing to broad scale. We observed a change in relative angular reactivity within 0.928 ~ 1.188 in low range and within 0.743 ~ 1.000 in high range from $-90^{\circ}$ to $+90^{\circ}$. The evaluation for energy dependence appeared a relative reactivity within 0.892 ~ 1.000 above 83 keV. This means PDR-1K isn't possible to use below 83 keV of radiation energy. It is possible to provide response information to user and to increase reliability of radiation measurement through this paper.

An Investigation on the Frequency Dependence of Soil Electrical Parameters

  • Lee, Bok-Hee;Kim, Ki-Bok
    • 조명전기설비학회논문지
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    • 제29권4호
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    • pp.69-76
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    • 2015
  • This paper presents the results of an investigation into the frequency-dependent electrical parameters for different types of soil as a function of moisture content. The frequency dependence of soil electrical parameters is very important in the design of grounding systems. In fact, the performance of grounding systems is greatly dependent upon various factors such as soil type, particle size, water content, temperature, frequency, and the like. The resistivity and relative permittivity for four different soils were measured and analyzed in the frequency range of 1kHz - 1MHz. Soil resistivity declined as moisture content and frequency increased. In particular, the frequency dependence of soil resistivity was significant as the moisture content was low. In contrast, the relative permittivity of soil dramatically declined at the frequency of 10kHz or below as the moisture content increased, showing the opposite pattern in terms of variation patterns, compared to resistivity.

전기집진장치에서 가스의 물리적인 특성에 따른 포집구역내의 입자포집율 연구 (A Study on the Mass Collection Efficiency in Collector Step of Electrostatic Precipitator by Physical Gas Characterization)

  • 하상안;임경택;신남철
    • 한국환경과학회지
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    • 제7권1호
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    • pp.36-40
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    • 1998
  • This study was carried out to investigate the collection Efficiency of mass in collector step at the different of physical gas characterization. This work has focused on the dependence of the collection efficiency of mass in the collector zone of a two-stage set up field with gas temperature T and the dew point tmeperature. To identify the dependence of the mass collection efficiency on the Bounded plate of the collector zone MP.k by the spectre electric resistance of dust $p_e$. and the relative humidify ${\varphi}$, 20 at- tempts have been made with three different gas temperature ($50{\circ}C, 80{\circ}C, 110{\circ}C$) at different dew point. At the specific electric resistance of dust $p_e$=$10^6{\Omega}m$ which relative humidity corresponds to $\phi$ > 15%, a easy rise of the sounded plate secluded dust mass share was measured atwain. As the result of the higher cohesion imprisonment power due to the adsorbtion of particle, the rinse of the relative humidity developed on the particle surface. Therefore, the collection efficiency of mass was not predominant the high temperature T in the collector zone, neither was the pecific ellectric resistance of dust dependent.

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습도에 따른 다이아몬드성 카본필름의 잔류응력 변화에 대한 연구 (Humidity Dependence of the Residual Stress of Diamond-like Carbon Film)

  • 이영진;김태영;이광렬;양인상
    • 한국진공학회지
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    • 제13권4호
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    • pp.157-163
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    • 2004
  • 라디오파 플라즈마 화학증착법 (radio frequency plasma assisted chemical vapor deposition: r.f.-PACVD) 법으로 증착된 다이아몬드성 카본 (Diamond-like Carbon : DLC) 필름에서 나타나는 습도에 따른 압축 잔류 응력의 변화 거동을 체계적으로 조사하였다. 합성에 사용된 탄화수소 가스의 종류와 -100V에서 -800V 범위의 기판 바이어스 전압의 조절을 통해 폴리머성 필름에서 흑연성 필름까지 광범위한 구조의 DLC 필름을 합성하였다. 상대습도가 10%-90% 범위에서 변화하는 분위기 챔버 내에서 박막의 잔류응력의 변화를 실시간으로 측정하였다 박막의 경도와 잔류응력이 최고 값을 가지는 합성조건에서 얻어진 치밀한 DLC박막에서는 습도에 따른 잔류응력의 변화가 관찰되지 않았다. 그러나, 폴리머상이나 흑연상의 박막에서는 두 경우 모두 습도가 높아짐에 따라 압축 잔류응력이 증가함을 관찰할 수 있었으며, 습도의 변화에 대해 잔류응력이 즉각적으로 변화하였다. 한편, 동일한 습도에서 압축 잔류응력의 증가량은 필름의 두께에 반비례하는 것이 관찰되었다. 이 결과는 물분자가 필름의 구조내로 침투하면서 생기는 변화가 아니라, 박막의 표면에서 일어나는 물분자와의 반응에 의해 필름의 잔류응력이 변할 수 있음을 의미한다.

Alkali Volatilization in TV Screen Glass Melts

  • Kim, Ki-Dong;Hwang, Jong-Hee
    • The Korean Journal of Ceramics
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    • 제6권4호
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    • pp.343-347
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    • 2000
  • The alkali volatilization of TV screen glass melts with various $K_2$O/R$_2$O mole fraction was investigated by dependence of weight loss on time. The melt conductivity was also determined to evaluate relative alkali diffusion in melts. Based on the results of time dependence and compositional dependence of volatilization combining the results of conductivity, the rate determining process of the volatilization was suggested. From the viewpoint of the production and the application of TV glass it was also discussed a correlation between the dependence of properties on $K_2$O/R$_2$O and the present commercial composition.

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제품특성과 구매패턴에 따른 uTradeHub 활용요인 연구 (An Empirical Study on the Factors Affecting the Participation of uTrade Hub in terms of Product Characteristics and Sourcing Patterns -Focused on the uTrade Search Services-)

  • 송선옥
    • 무역상무연구
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    • 제49권
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    • pp.461-490
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    • 2011
  • The purpose of this study is to examine which factors are encouraging SMEs to participate in uTradeHub(focused on the uTrade search service) in terms of product characteristics and sourcing patterns. The three factors encouraging Trade e-Marketplaces are identified in this study. First, internal factors include the support of top management, mature of IT infrastructure. Second, external factors include the pressure of industry, industry competition, dependence of trading partners. Third perception factors are perceived Usefulness, perceived easy of use. The empirical analysis had the following results. First, it reveals that support of top management, mature of IT infrastructure, industry competition have significant influence upon uTrade Search Services. On the other hand, pressure of industry, dependence of trading partners, Perceived relative benefits are not significant variable of the participation in uTrade Search Services. Second, the factors affecting the participation in uTrade Search Services are differentiated in terms of product characteristics and sourcing patterns. And the support of top management, mature of IT infrastructure, Perceived relative benefits are emphasized very important factors affecting the participation of uTrade Search Services in SMEs. The industry competition is recognized as more important factor in horizontal market in which Spot sourcing just like Operating products is trading. On the other hands, the dependence of trading partners are significant factor in vertical market in which Systemic sourcing just like Manufacturing products is trading.

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