• Title/Summary/Keyword: Mass bias

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Fabrications and Characteristics of Infrared Sensor for Passenger Conditional Detection in Vehicle (차량 내 탑승자 상태 인식용 적외선 센서의 제조 및 특성)

  • Lee, Sung-Hyun;Nam, Tae-Woon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.3
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    • pp.222-229
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    • 2009
  • A noble infrared sensor was studied for passenger conditional detection in vehicle, This research relates to uncooled infrared sensors for detecting the presence, type and temperature of occupants in vehicle. It sense that the occupants purpose to control the smart airbag for safety in the case of adult or child and to control the automatic air conditioning for convenience. This paper described the design and the fabrication of microbolometers which were composed of 2 by 8 elements using the surface micromachining technology. The characteristics of the array were investigated in the spectral region of $8{\sim}12{\mu}m$. The fabricated detectors exhibited the thermal mass of $7.05{\times}10^{-9}\;J/K$, the thermal conductance of $1.03{\times}10^{-6}\;W/K$, the thermal time constant of 6.8 ms, the responsivity of $2.96{\times}10^4\;V/W$ and the detectivity of $1.01{\times}10^9\;cmHz^{1/2}/W$, at the chopper frequency of 10 Hz and the bias current of $4.4{\mu}A$. We could successfully detect the human body condition in the divided zone. As a results, we concluded that microbolometer optimized in this research could be useful for the application of passenger conditional detection in vehicle.

SVM을 이용한 지구에 영향을 미치는 Halo CME 예보

  • Choe, Seong-Hwan;Mun, Yong-Jae;Park, Yeong-Deuk
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.61.1-61.1
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    • 2013
  • In this study we apply Support Vector Machine (SVM) to the prediction of geo-effective halo coronal mass ejections (CMEs). The SVM, which is one of machine learning algorithms, is used for the purpose of classification and regression analysis. We use halo and partial halo CMEs from January 1996 to April 2010 in the SOHO/LASCO CME Catalog for training and prediction. And we also use their associated X-ray flare classes to identify front-side halo CMEs (stronger than B1 class), and the Dst index to determine geo-effective halo CMEs (stronger than -50 nT). The combinations of the speed and the angular width of CMEs, and their associated X-ray classes are used for input features of the SVM. We make an attempt to find the best model by using cross-validation which is processed by changing kernel functions of the SVM and their parameters. As a result we obtain statistical parameters for the best model by using the speed of CME and its associated X-ray flare class as input features of the SVM: Accuracy=0.66, PODy=0.76, PODn=0.49, FAR=0.72, Bias=1.06, CSI=0.59, TSS=0.25. The performance of the statistical parameters by applying the SVM is much better than those from the simple classifications based on constant classifiers.

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Missing Type I AGNs in the local universe

  • Kim, Ji Gang;Kim, Jae Hyuk;Lee, Seung Eon;Park, Daeseong;Woo, Jong-Hak;Kwon, HongJin
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.83.2-83.2
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    • 2012
  • Type I AGNs are classified by the presence of broad emission lines while Type II AGNs show narrow emission lines only. All-sky surveys such as SDSS provide large AGN samples for statistical studies. However, the AGN samples suffer selection bias due to the incomplete selection criteria. To investigate the missing Type I AGNs in optical spectroscopic surveys, we start with a sample of SDSS Type II AGNs at 0.02 < z < 0.05, using the MPA-JHU SDSS DR7 catalog. We search for the hidden broad $H{\alpha}$ component with both visual inspection and the multi-component spectral decomposition method. Out of 1383 Type II AGNs, we find a total of 62 missing Type I AGNs (~4.5%). The sample has mean black hole mass, log $(M_{BH}/M_{SUN))=6.48{\pm}0.53$, and luminosity, log $(L_{H{\alpha}}/ergs^{-1})=40.52{\pm}0.33$, with Eddington ratio, log $(L_{bol}/L_{Edd})=-1.51{\pm}0.41$. We will describe the sample and present the $M_{BH}-{\sigma}_*$, and $M_{BH}-M_*$ relations of the sample in the context of the BH-galaxy coevolution.

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Fabrications and Characteristics of Infrared Sensor Composed of λ/4 Absorbing Structure for the Application of NDIR CO2 Gas Sensor (λ/4 흡수층 구조를 갖는 NDIR 이산화탄소 가스센서용 적외선 센서의 제조 및 특성)

  • Lee, Sung-Hyun;Nam, Tae-Woon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.11
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    • pp.1005-1009
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    • 2008
  • A noble infrared $\lambda/4$ absorbing structure using metal reflector was studied for uncooled infrared sensors. This paper described the design and the fabrication of IR uncooled detectors which were composed of 21 by 21 elements using the surface micromachining technology. The characteristics of the array were investigated in the spectral region of 4.26 ${\mu}m$. The fabricated detectors exhibited the thermal mass of $9.75\times10^{-9}$ J/K, the thermal conductance of $1.31\times10^{-6}$ W/K, the thermal time constant of 7.4 ms, the responsivity of $1.07\times10^5$ V/W and the detectivity of $1.04\times10^9$ $cmHz^{1/2}/W$, at the chopper frequency of 10 Hz and the bias current of 9.22${\mu}A$. Finally the absorptance efficiency of $\lambda/4$ absorbing structure was about 23.2 % higher than that of absence absorbing structure.

IDENTIFICATION OF POSSIBLE MERCURY SOURCES AND ESTIMATION OF MERCURY WET DEPOSITION FLUX IN LAKE ONTARIO FROM LAKE ONTARIO ATMOSPHERIC DEPOSITION STUDY (LOADS)

  • Han, Young-Ji
    • Environmental Engineering Research
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    • v.10 no.6
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    • pp.306-315
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    • 2005
  • Total gas phase mercury (TGM) concentrations and event wet-only precipitation for Hg were collected for nine months (from April, 2002 to Dec., 2002) at Sterling, NY on the shoreline of Lake Ontario. TGM concentrations measured in this study ($3.02{\pm}2.14\;ng/m^3$) were in somewhat high range compared to other background sites. Using simplified quantitative transport bias analysis (SQTBA) possible sources affecting high Hg concentration in Sterling was identified, and they are coal-fired power plants located in southern NY and Pennsylvania. Wet deposition measured at Mercury Deposition Network (MDN) sites including Pt. Petre and Egbert, ON were compared with data obtained at the Sterling to estimate the total mercury wet deposition flux to Lake Ontario. The wet deposition flux was calculated to be the highest at the Sterling site ($7.94\;{\mu}g/m^2$ from April, 2002 to Dec. 2002) and the lowest at the Egbert ($3.92\;{\mu}g/m^2$), due to the both the difference in precipitation depth and Hg concentration in the precipitation. The deposition measured at the Sterling site is similar to Lake Michigan deposition of $6-14\;{\mu}g/m^2$ (converted for ninth months) measured for Lake Michigan Mass Balance Study (LMMBS).

Analysis of Impact of Climate Change on River Flows in an Agricultural Watershed Using a Semi-distributed Watershed Model STREAM (준분포형 유역모델 STREAM을 이용한 기후변화가 농업유역의 하천유량에 미치는 영향 분석)

  • Jeong, Euisang;Cho, Hong-Lae
    • Journal of Korean Society on Water Environment
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    • v.35 no.2
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    • pp.131-144
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    • 2019
  • Climate Change affects the hydrological cycle in agricultural watersheds through rising air temperature and changing rainfall patterns. Agricultural watersheds in Korea are characterized by extensive paddy fields and intensive water use, a resource that is under stress from the changing climate. This study analyzed the effects of climate change on river flows for Geum Cheon and Eun-San Choen watershed using STREAM, a semi-distributed watershed model. In order to evaluate the performance and improve the reliability of the model, calibration and validation of the model was done for one flow observation point and three reservoir water storage ratio points. Climate change scenarios were based on RCP data provided by the Korea Meteorological Administration (KMA) and bias corrections were done using the Quantile Mapping method to minimize the uncertainties in the results produced by the climate model to the local scale. Because of water mass-balance, evapotranspiration tended to increase steadily with an increase in air temperature, while the increase in RCP 8.5 scenario resulted in higher RCP 4.5 scenario. The increase in evapotranspiration led to a decrease in the river flow, particularly the decrease in the surface runoff. In the paddy agricultural watershed, irrigation water demand is expected to increase despite an increase in rainfall owing to the high evapotranspiration rates occasioned by climate change.

Comparison of the Democratic Concepts of the People in Mainland China and Taiwan: Support and Understanding

  • Wu, Hsin-Che;Xiao, Long
    • Asian Journal for Public Opinion Research
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    • v.9 no.1
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    • pp.3-24
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    • 2021
  • Through an empirical comparative analysis, we found that people in mainland China and Taiwan demonstrate strong similarities in their support for democracy, based on democratic suitability, efficiency, preference, and priority. There are also differences in beliefs about democratic values. Compared to people in mainland China, the Taiwanese have a deeper and more widely shared belief in the principles of participation and pluralism, while the differences between their beliefs in the principles of equality, freedom, and checks and balances are narrow. Furthermore, people in mainland China and Taiwan have a strong similarity in their understanding of democracy, that is, they all present a mixed democratic understanding based on substantive bias. Overall, although the differences between mainland China and Taiwan's democratic practices are reflected in the level of value identification from the perspective of democratic support and democratic understanding, the popular democratic political culture in mainland China and Taiwan still has a relatively broad consensus. Thus, the integration and development of cross-strait relations not only has an increasingly profound social and economic foundation but also considerable consensus and mass support on the political and cultural level.

Application of GMDH model for predicting the fundamental period of regular RC infilled frames

  • Tran, Viet-Linh;Kim, Seung-Eock
    • Steel and Composite Structures
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    • v.42 no.1
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    • pp.123-137
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    • 2022
  • The fundamental period (FP) is one of the most critical parameters for the seismic design of structures. In the reinforced concrete (RC) infilled frame, the infill walls significantly affect the FP because they change the stiffness and mass of the structure. Although several formulas have been proposed for estimating the FP of the RC infilled frame, they are often associated with high bias and variance. In this study, an efficient soft computing model, namely the group method of data handling (GMDH), is proposed to predict the FP of regular RC infilled frames. For this purpose, 4026 data sets are obtained from the open literature, and the quality of the database is examined and evaluated in detail. Based on the cleaning database, several GMDH models are constructed and the best prediction model, which considers the height of the building, the span length, the opening percentage, and the infill wall stiffness as the input variables for predicting the FP of regular RC infilled frames, is chosen. The performance of the proposed GMDH model is further underscored through comparison of its FP predictions with those of existing design codes and empirical models. The accuracy of the proposed GMDH model is proven to be superior to others. Finally, explicit formulas and a graphical user-friendly interface (GUI) tool are developed to apply the GMDH model for practical use. They can provide a rapid prediction and design for the FP of regular RC infilled frames.

The Improved Method for Precise Determination of Pu Isotope Ratio using MC-ICP-MS (다중검출기유도결합플라즈마질량분석기를 이용한 Pu 동위원소비 정밀 분석법)

  • Yim, Seong-A;Han, Eun-Mi;Chae, Jung-Seok;Yun, Ju-Young
    • Journal of Radiation Protection and Research
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    • v.35 no.3
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    • pp.117-123
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    • 2010
  • Plutonium is by far the most important of the transuranic elements which have been released into the environment due to radio-toxicity and long term radiation effects on humans. And Pu isotope ratio ($^{240}Pu/^{239}Pu$) is of great interest because this ratio is used as a fingerprint for different sources. Mass spectrometry has been used as an useful atom counting technique with several advantages over decay counting techniques for the determination of Pu isotopes. It enables a determination of Pu isotope ratio in the environmental samples with a low detection limit and a short determination time. An ICP-MS is the representative mass spectrometry for Pu determination. In this study, the precision of $^{240}Pu/^{239}Pu$ isotope ratio was improved by using 4 multiple ion counters of MC-ICP-MS. The detection limit of $^{239}Pu$ and $^{240}Pu$ were $0.10\;fg\;ml^{-1}$ ($0.24\;{\mu}Bq\;ml^{-1}$), $0.12\;fg\;ml^{-1}$ ($0.97\;{\mu}Bq\;ml^{-1}$), respectively. The relative standard deviation of $^{240}Pu/^{239}Pu$ isotope ratio was less than 1 % in trace level. The various reference materials (seawater, soil and sediment) were analyzed to verify this method and their analytical results were in good agreement with the certified (or recommended value) value.

Covert Cohabitation of News and Advertisement: News Frame Towards Advertisers of the Media (뉴스와 광고의 은밀한 동거: 광고주에 대한 언론의 뉴스구성)

  • Lim, Bong-Soo;Lee, Wan-Soo;Lee, Min-Kyu
    • Korean journal of communication and information
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    • v.66
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    • pp.133-158
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    • 2014
  • This research followed the major South Korean newspapers, Chosun, JoongAng, HanKyoreh and KyungHyang newspapers to study their relationship with advertisement - on how they use advertisement to what degree and which views they take, also looking into the quantity of advertisement. The results of analysis is as thus: first, the more advertised companies tended to have more news reports about them overall. Also, advertised companies were usually shown in positive light rather than a negative one. The most notable constructive commonality found in the positively advertised companies were that they were not usually introduced upfront through the title of the news article (or within the body of the article) but rather mentioned within the media frame. The reasons for this pattern in advertising is to make bias towards JoongAng which is obvious for pro companies, especially for the Chosun which is known for being neutral in most company matters even for the HanKyoreh, KyungHyang known for their usual negative attitude towards private companies.

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