• 제목/요약/키워드: MIS 5a

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$Ta_2O_5/Al/SiO_2/P-Si$ MIS형(形) 태양전지(太陽電池)의 제작(製作)과 특성(特性) (Fabrication and Characteristics of $Ta_2O_5/Al/SiO_2/p-Si$ MIS Solar Cells)

  • 노경석;손연규
    • 태양에너지
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    • 제6권2호
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    • pp.70-75
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    • 1986
  • The fabrication procedure and characteristics of $Ta_2O_5/Al/SiO_2/p-Si$ MIS solar cells forming a fine grating pattern of aluminum evaporated on to p-type silicon crystal are discribed. The proper temperature for oxide growing of these cells was found to be about $450^{\circ}C$ for 20 minutes with oxygen flow. The conversion efficiency increased about 3% after $750{\AA}$ thickness of tantalium silica film spin on anti-reflective coating. The best results showed that $V_{oc}=0.545V,\;J_{sc}=34mA$ and F.F = 0.65, which represent that the conversion efficiency is 12%.

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로스해 Iselin Bank에서 규조를 이용한 고해양 환경변화 해석 (Analysis of Changes in Paleoenvironment using Diatoms from Iselin Bank in the Ross Sea)

  • 박영숙;김성한;이재일;유규철;이민경
    • 한국지구과학회지
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    • 제42권6호
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    • pp.677-687
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    • 2021
  • 로스해의 Iselin Bank 인근에서 채취한 RS15-GC41코어로부터 규조를 분석한 결과 총 24속 35종의 규조를 감정하였으며, 규조 개체수 농도는 0.2-28.6×106/g 범위에 해당하였다. 규조 군집 조성에 의해 4개의 규조 군집대를 설정하였으며 규조 군집의 변화는 거의 10만년을 주기로 변화 하였다. Marine Isotope Stages 1-11 시기에 RS15-GC41이 퇴적되는 동안 간빙기(Interglacial)에는 open ocean을 지시하는 Rhizosolenia styliformis, Fragilariopsis kerguelensis와 Thalassionema nitzschioides등이 풍부하게 산출되며, 빙기(Glacial)에는 sea-ice종인 Actinocyclus actinocyclus의 산출이 풍부하게 나타난다. MIS 7, 9와 11의 간빙기 동안 MIS 1, 3과 5 시기보다 sea-ice의 분포가 더 넓고 지속 기간이 더 오래 계속되었음을 알 수 있다. Paralia sulcata는 이 시기(MIS 7, 9와 11) 동안 해류에 의한 ice-rafted debris의 유입과 함께 연안지역으로부터 재이동 되었음을 뒷받침 해 준다.

$Al/Al_2O_3/Si$(100) Solar Cell 제작 및 특성 평가

  • 민관홍;유정재;연제민;찬타솜바스 시사바이;정상현;김광호
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.313.2-313.2
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    • 2013
  • 본 연구에서는 기존에 연구된 Solar Cell 보다 구조 및 제작이 단순한 $Al/Al_2O_3/Si$(100) Solar cell을 제작하여 평가하였다. 기판으로는 p-type Si(100), 0.5~2 ${\Omega}{\cdot}cm$을 사용하여 chemical cleaning 후 ALD(Atom Layer Deposition)법으로 Al2O3 터널링 절연막을 증착하였으며, 박막의 두께를 1~10 nm로 변화시켜 MIS 커패시터의 터널링 효과를 평가하였다. MIS 커패시터의 전기적 특성평가를 위해 누설전류 밀도-전계 특성은 pA meter/DC Voltage source를 사용하였고, 커패시턴스-전압특성, D-factor 특성은 precision LCR meter를 사용하였다. $Al/Al_2O_3/Si$(100) Solar cell의 특성평가를 위해 300~1100nm 파장영역에 따른 양자 효율을 평가하기 위해 Quantum Efficiency system (QE)을 사용하였고, Stanard Test Conditions 100 $mW/cm^2$, AM1.5, $25^{\circ}C$ 조건의 Voc, Isc, Jsc, FF (Fill Factor) 및 Efficiency(%)를 평가하기 위해 Solar simulator를 이용하였다.

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부산 다대포 지역 해안 단구 제1면의 구정선 고도와 형성 시기 (The Elevation of Paleo-shoreline and Formation Age of the 1st Marine Terrace in Dadaepo, Busan, South Korea)

  • 신재열;홍영민;홍성찬
    • 한국지형학회지
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    • 제26권4호
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    • pp.67-79
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    • 2019
  • This study documents the level of paleo-shoreline and the timing of formation of the lowest marine terrace (1st terrace) distributed in Dadaepo, Busan, South Korea. In the study area, the elevation of paleo-shoreline of the 1st terrace is clearly identified as 5 meters above mean high tide based on the elevation of wave-cut platforms and the elevation of boundary between marine and terrestial sediments. This is well consistent with the fact that are found along the Southern coast of the Korean Peninsula including Daepo-dong, Sacheon-si. The timing of formation of the 1st terrace in Dadaepo is confirmed to have been deposited around 70,000~80,000 years BP (MIS 5a) according to OSL and IRSL dating ages. However, because the formation age of the 1st terrace in Sacheon-si Daepo-dong (Southerm coast) and Pohang-si Umok-ri (Eastern coast) previously identified as about 90,000~100,000 years BP (MIS 5c), further discussion of what is needed. Possibly, it can be interpreted that the sub-interglacial (MIS 5a and 5c) sea-level records during the last interglacial period are likely to be selective on land depending on regions.

전남 완도군 신지면 일대의 고해안퇴적층과 최종간빙기 고해수면 증거 (The Evidence for the High Sea Level of MIS 5e and the Paleo-coastal Sediments from Sinji-myen, Wando-gun, Jeollanam-do, Korea)

  • 신원정;이재호;변종민;김종연
    • 한국지형학회지
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    • 제26권1호
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    • pp.59-78
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    • 2019
  • The physical and chemical characteristics of more than 5 m sandy deposits behind the beach in Sinji-do Island are investigated and its burial ages are estimated using Optically Stimulated Luminescence. By the estimated burial ages of the sandy deposits, this section is divided into four sub-units: Unit I (6.2 ka), Unit II (23.2 ka), Unit III (115.9 ka), and Unit IV (115.9 to 127.5 ka). It can be proposed that the Unit I of a coarse sand deposited during the Holocene Climatic Optimum. Unit II, supposed to be the aeolian sediments, formed during the Last Glacial Maximum (LGM). It can be supposed that the study area was not affected by the marine processes during the LGM, directly. Unit III is more consolidated deposits of coarse silt to fine sand and deposited during the Last Interglacial Period. Unit IV mainly consist of beach gravels with sandy matrix deposited during the Marine Isotope Stage 5e (MIS 5e), and thus indicates that the sea level of the southwest sea had risen 3 to 5 m above present sea level during the MIS 5e.

국내 MIS 연구에서 구조방정식모형 활용에 관한 메타분석 (A Meta Analysis of Using Structural Equation Model on the Korean MIS Research)

  • 김종기;전진환
    • Asia pacific journal of information systems
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    • 제19권4호
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    • pp.47-75
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    • 2009
  • Recently, researches on Management Information Systems (MIS) have laid out theoretical foundation and academic paradigms by introducing diverse theories, themes, and methodologies. Especially, academic paradigms of MIS encourage a user-friendly approach by developing the technologies from the users' perspectives, which reflects the existence of strong causal relationships between information systems and user's behavior. As in other areas in social science the use of structural equation modeling (SEM) has rapidly increased in recent years especially in the MIS area. The SEM technique is important because it provides powerful ways to address key IS research problems. It also has a unique ability to simultaneously examine a series of casual relationships while analyzing multiple independent and dependent variables all at the same time. In spite of providing many benefits to the MIS researchers, there are some potential pitfalls with the analytical technique. The research objective of this study is to provide some guidelines for an appropriate use of SEM based on the assessment of current practice of using SEM in the MIS research. This study focuses on several statistical issues related to the use of SEM in the MIS research. Selected articles are assessed in three parts through the meta analysis. The first part is related to the initial specification of theoretical model of interest. The second is about data screening prior to model estimation and testing. And the last part concerns estimation and testing of theoretical models based on empirical data. This study reviewed the use of SEM in 164 empirical research articles published in four major MIS journals in Korea (APJIS, ISR, JIS and JITAM) from 1991 to 2007. APJIS, ISR, JIS and JITAM accounted for 73, 17, 58, and 16 of the total number of applications, respectively. The number of published applications has been increased over time. LISREL was the most frequently used SEM software among MIS researchers (97 studies (59.15%)), followed by AMOS (45 studies (27.44%)). In the first part, regarding issues related to the initial specification of theoretical model of interest, all of the studies have used cross-sectional data. The studies that use cross-sectional data may be able to better explain their structural model as a set of relationships. Most of SEM studies, meanwhile, have employed. confirmatory-type analysis (146 articles (89%)). For the model specification issue about model formulation, 159 (96.9%) of the studies were the full structural equation model. For only 5 researches, SEM was used for the measurement model with a set of observed variables. The average sample size for all models was 365.41, with some models retaining a sample as small as 50 and as large as 500. The second part of the issue is related to data screening prior to model estimation and testing. Data screening is important for researchers particularly in defining how they deal with missing values. Overall, discussion of data screening was reported in 118 (71.95%) of the studies while there was no study discussing evidence of multivariate normality for the models. On the third part, issues related to the estimation and testing of theoretical models on empirical data, assessing model fit is one of most important issues because it provides adequate statistical power for research models. There were multiple fit indices used in the SEM applications. The test was reported in the most of studies (146 (89%)), whereas normed-test was reported less frequently (65 studies (39.64%)). It is important that normed- of 3 or lower is required for adequate model fit. The most popular model fit indices were GFI (109 (66.46%)), AGFI (84 (51.22%)), NFI (44 (47.56%)), RMR (42 (25.61%)), CFI (59 (35.98%)), RMSEA (62 (37.80)), and NNFI (48 (29.27%)). Regarding the test of construct validity, convergent validity has been examined in 109 studies (66.46%) and discriminant validity in 98 (59.76%). 81 studies (49.39%) have reported the average variance extracted (AVE). However, there was little discussion of direct (47 (28.66%)), indirect, and total effect in the SEM models. Based on these findings, we suggest general guidelines for the use of SEM and propose some recommendations on concerning issues of latent variables models, raw data, sample size, data screening, reporting parameter estimated, model fit statistics, multivariate normality, confirmatory factor analysis, reliabilities and the decomposition of effects.

실내모형시험을 통한 OPC와 친환경 MIS 그라우트의 지반 침투성능 분석 (Analysis of Permeation Efficiency in Soil for OPC and Non-Pollution MIS Grouts by Laboratory Model Test)

  • 안정호;임희대;최동남;송영수
    • 자원환경지질
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    • 제45권3호
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    • pp.307-315
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    • 2012
  • 본 연구에서는 보통 포틀랜드 시멘트 OPC(Ordinary Portland Cement)와 MIS(Micro-Injection Process System) 공법에서 사용하고 있는 마이크로 시멘트의 지반 침투성능을 평가하기 위해 실내모형시험을 수행하였다. 이를 위해 그라우트 주입을 일정한 방법으로 재현할 수 있는 가압침투주입장치를 제작하였으며 공시체 제작방법을 마련하였다. 물시멘트비를 5:1에서 1:1까지 변화하여 주입시험을 수행한 결과 물시멘트비가 증가함에 따라 침투성능이 선형적으로 증가하였으며 주입성능을 비교하면 상대적으로 비표면적이 큰 MIS가 OPC보다 동일한 배합비에서 침투성능이 우수한 것으로 나타났다. 특히 물시멘트비가 2:1~1:1의 부배합에서 OPC의 침투성능이 매우 낮은 것으로 관찰되었다. 또한 침투량과 주입시간과의 관계곡선을 hyperbolic으로 모델링하여 예측치를 산정하고 이를 측정치와 비교한 결과 그라우트 성능평가에 대한 hyperbolic 모델의 잠재력이 검증되었다.

Effects of the Misspecification of Cointegrating Ranks in Seasonal Models

  • Seong, Byeong-Chan;Cho, Sin-Sup;Ahn, Sung-K.;Hwang, S.Y.
    • 응용통계연구
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    • 제21권5호
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    • pp.783-789
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    • 2008
  • We investigate the effects of the misspecification of cointegrating(CI) ranks at other frequencies on the inference of seasonal models at the frequency of interest; our study includes tests for CI ranks and estimation of CI vectors. Earlier studies focused mostly on a single frequency corresponding to one seasonal root at a time, ignoring possible cointegration at the remaining frequencies. We investigate the effects of the mis-specification, especially in finite samples, by adopting Gaussian reduced rank(GRR) estimation by Ahn and Reinsel (1994) that considers cointegration at all frequencies of seasonal unit roots simultaneously. It is observed that the identification of the seasonal CI rank at the frequency of interest is sensitive to the mis-prespecification of the CI ranks at other frequencies, mainly when the CI ranks at the remaining frequencies are underspecified.

산화알루미늄 박막의 두께 및 열처리 온도에 따른 Al2O3/GaN MIS 구조의 전기적 특성 변화 (Change in Electrical Properties of Al2O3/GaN MIS Structures according to the Thickness of Al2O3 Thin Film and Annealing Temperature)

  • 곽노원;이우석;김가람;김현준;김광호
    • 한국전기전자재료학회논문지
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    • 제22권6호
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    • pp.470-475
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    • 2009
  • We deposited $Al_2O_3$ thin films on GaN by remote plasma atomic layer deposition (RPALD) technique, trimethylaluminum(TMA) and oxygen were used as precursors, at fixed process condition, the number of cycle were changed. Growth rate per cycle was $1.2\;{\AA}$/cycle. and Growth rate was in proportion to a number of cycle, the GaN MIS capacitors that $Al_2O_3$ thin film were deposited above 12 nm, have excellent electrical properties, a low electrical leakage current density(${\sim}10^{-10}\;A/cm^2$ at 1.5 MV), but below 12 nm, we can see the degradation of the leakage current density. After post deposition annealing, Dielectric constant was estimated by 1 MHz high-frequency C-V method, it was varied with the anealing temperature from 6.9 at no post anealed to 7.6 at $800^{\circ}C$, and we can see a improvement of the leakage current density and breakdown voltage by post deposition anealing below $700^{\circ}C$, but, after anealed at $800^{\circ}C$, we can see the degradation of the leakage current density and breakdown voltage.

감지막으로 Ta2O5를 이용한 정전용량형 수소 가스센서 (Capacitive-type Hydrogen Gas Sensor Using Ta2O5 as Sensitive Layer)

  • 최제훈;김성진
    • 한국전기전자재료학회논문지
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    • 제26권12호
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    • pp.882-887
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    • 2013
  • We investigated a SiC-based hydrogen gas sensor with metal-insulator-semiconductor (MIS) structure for high temperature process monitoring and leak detection applications. The sensor was fabricated by Pd/$Ta_2O_5$/SiC structure, and a thin tantalum oxide ($Ta_2O_5$) layer was exploited with the purpose of sensitivity improvement, because tantalum oxide has good stability at high temperature as well as high permeability for hydrogen gas. In the experiment, dependence of I-V characteristics and capacitance response properties on hydrogen gas concentrations from 0 to 2,000 ppm was analyzed at room temperature to $500^{\circ}C$. As the result, our sensor exploiting a $Ta_2O_5$ dielectric layer showed possibilities with regard to use in hydrogen gas sensors for high-temperature applications.