• 제목/요약/키워드: Biases

검색결과 583건 처리시간 0.036초

Geolocation Error Analysis of KOMPSAT-5 SAR Imagery Using Monte-Carlo Simulation Method

  • Choi, Yoon Jo;Hong, Seung Hwan;Sohn, Hong Gyoo
    • 한국측량학회지
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    • 제37권2호
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    • pp.71-79
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    • 2019
  • Geolocation accuracy is one of the important factors in utilizing all weather available SAR satellite imagery. In this study, an error budget analysis was performed on key variables affecting on geolocation accuracy by generating KOMPSAT-5 simulation data. To perform the analysis, a Range-Doppler model was applied as a geometric model of the SAR imagery. The results show that the geolocation errors in satellite position and velocity are linearly related to the biases in the azimuth and range direction. With 0.03cm/s satellite velocity biases, the simulated errors were up to 0.054 pixels and 0.0047 pixels in the azimuth and range direction, and it implies that the geolocation accuracy is sensitive in the azimuth direction. Moreover, while the clock drift causes a geolocation error in the azimuth direction, a signal delay causes in the range direction. Monte-Carlo simulation analysis was performed to analyze the influence of multiple geometric error sources, and the simulated error was up to 3.02 pixels in the azimuth direction.

Behavioral Investor Types and Financial Market Players in Oman

  • SHA, Nadia;ISMAIL, Mohammed Yousoof
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.285-294
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    • 2021
  • The most basic forces of stock market are supply and demand, which increases or decreases on the basis of information. The crucial point is that investor's perception is depending on the availability of information at a particular time. But it is very difficult to understand what they take from a piece of information, and the decision varies from person to person; hence, it is important to understand the behavior of investors in the stock market. In this context, this study is focusing on behavioral investor-type diagnosis testing among financial market players (FMPs) in Oman. The study conducted a review of behavioral types among stock market investors, and attempted to assess the influence of age and gender factors on investor bias. It classifies investor type biases according to the gender and age of respondents. This study employs primary data with a structured questionnaire distributed to an equal number of male and female stock market investors in Muscat Securities Market. The study used sample t-test, one-way ANOVA, CATPCA and ALSCAL to identify the significant difference among age, gender and experience of the respondents. The present study found that all of the investors are influenced by different cognitive biases and, moreover, it depends on investor's gender.

Stock Selection Model in the Formation of an Optimal and Adaptable Portfolio in the Indonesian Capital Market

  • SETIADI, Hendri;ACHSANI, Noer Azam;MANURUNG, Adler Haymans;IRAWAN, Tony
    • The Journal of Asian Finance, Economics and Business
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    • 제9권9호
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    • pp.351-360
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    • 2022
  • This study aims to determine the factors that can influence investors in selecting stocks in the Indonesian capital market to establish an optimal portfolio, and find phenomena that occurred during the COVID-19 pandemic so that buying interest / the number of investors increased in the Indonesian capital market. This study collection technique uses primary data obtained from the survey questionnaire and secondary data which is market data, stock price movement data sourced from the Indonesia Stock Exchange, Indonesian Central Securities Depository, and Bank Indonesia, as well as empirical literature on behavior finance, investment decision, and interest in buying stock. The method used in this research is the survey questionnaire analysis with the SEM (statistical approach). The results of the analysis using SEM show that investor behavior influences the stock-buying interest, investor behavior, and the stock-buying interest influences investor decision-making. However, risk management does not influence investor-decision making. This occurs when the investigator's psychological capacity produces more decision information by decreasing all potential biases, allowing the best stock selection model to be selected. When the investigator's psychological capacity creates more decision information by reducing biases, the optimum stock selection model can be chosen.

Does Gender Influence Investment Choice? A Psychosomatic Study of GCC Entrepreneurs

  • KHAN, Mohammed Abdul Imran;JAMIL, Syed Ahsan;KHAN, Shahebaz Sarfaraz;ALI, Meer Mazhar
    • The Journal of Asian Finance, Economics and Business
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    • 제9권4호
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    • pp.299-306
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    • 2022
  • Entrepreneurs with behavioral finance biases are more likely to make irrational or financially detrimental decisions. Understanding financial behavior biases can assist in making sound financial decisions. Behavioral finance is a new topic that can assist researchers in better understanding investor behavior and preferences while purchasing and selling stocks. Using measures such as independent t-tests and average Likert five-point scale scores, this study seeks to determine how entrepreneurs make investment decisions and whether gender makes a difference. The study is empirical, and data from 1000 entrepreneurs were collected through convenience sampling. The study's main findings show that there are numerous factors to consider while investing in stocks, including family planning, children's education, investment security, and recurring income. Both men and women attempt to invest in many asset classes, but certain investments are extremely risky, while others are low risk. As a result, investors should assess risk based on their age and experience rather than their gender; this indicates that an investment in venture capital has nothing to do with gender but everything to do with the investor's age.

Multigroup cross-sections generated using Monte-Carlo method with flux-moment homogenization technique for fast reactor analysis

  • Yiwei Wu;Qufei Song;Kuaiyuan Feng;Jean-Francois Vidal;Hanyang Gu;Hui Guo
    • Nuclear Engineering and Technology
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    • 제55권7호
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    • pp.2474-2482
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    • 2023
  • The development of fast reactors with complex designs and operation status requires more accurate and effective simulation. The Monte-Carlo method can generate multi-group cross-sections in arbitrary geometry without approximation on resonances treatment and leads to good results in combination with diffusion codes. However, in previous studies, the coupling of Monte-Carlo generated multi-group cross-sections (MC-MGXS) and transport solvers has shown relatively large biases in fast reactor problems. In this paper, the main contribution to the biases is proved to be the neglect of the angle-dependence of the total cross-sections. The flux-moment homogenization technique (MHT) is proposed to take into account this dependence. In this method, the angular dependence is attributed to the transfer cross-sections, keeping an independent form for the total sections. For the MET-1000 benchmark, the multi-group transport simulation results with MC-MGXS generated with MHT are improved by 700 pcm and an additional 120 pcm with higher order scattering. The factors that cause the residual bias are discussed. The core power distribution bias is also significantly reduced when MHT is used. It proves that the MCMGXS with MHT can be applicable with transport solvers in fast reactor analysis.

GOCI-II Level 1B 분할영상 간의 복사 편차에 대한 초기 분석 (A Preliminary Analysis on the Radiometric Difference Across the Level 1B Slot Images of GOCI-II)

  • 김원국;임태홍;안재현;최종국
    • 대한원격탐사학회지
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    • 제37권5_2호
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    • pp.1269-1279
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    • 2021
  • 최근 성공적으로 발사되어 운영되고 있는 천리안 해양위성 2호(GOCI-II)는 3×4로 배열되어 있는 총 12장의 Level 1B분할영상을 통해 Local Area전체를 관측할 수 있다. 이 때 분할영상 간의 복사휘도의 차이가 발생하면 분할영상의 경계에서 불연속선이 나타나게 되는데, 그 불연속선은 2차 산출물에서 더 도드라지게 나타나는 경향이 있어 사용 전에 분할영상 간 복사휘도의 차이에 대한 면밀한 분석 및 교정이 필요하다. 본 연구는 분할영상 간에 존재하는 중첩 영역을 이용하여 복사휘도의 상대적인 편의를 추정하고자 한다. 신뢰도 높은 통계 여러 날의 영상을 대량으로 분석해야 얻을 수 있겠지만, 본 초기 연구에서는 우선 한 시각에 촬영된 12개의 Level 1B 영상에 대한 통계를 도출함으로써 복사휘도 편차의 특성에 대해 이해하고 분산도 및 편의에 대한 전반적인 거동에 대한 분석을 수행한다. 사용 영상으로는 한반도 주변이 비교적 구름이 없는 날이었던 2021년 2월 21일 UTC03시 영상을 이용하였고, 신뢰도 높은 통계치 도출을 위하여 해양화소 만을 추출하여 사용하였다. 분석 결과는 밴드 1(380 nm)을 제외한 모든 밴드에서 0~1% 크기의 상대 편의가 나타남을 확인하였고, 밴드 1은 1~2% 가량의 보다 큰 편의를 보였다. 남북 방향으로 배열된 분할영상 쌍의 밴드 1의 경우를 제외하면, 동서, 남북 배열된 방향에 관계없이 모든 밴드에서 편의의 방향은 태양고도의 변화가 유발하는 편의의 방향과 반대로 나타났다.

Impact of Gamma Irradiation Effects on IGBT and Design Parameter Considerations

  • Lho, Young-Hwan
    • ETRI Journal
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    • 제31권5호
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    • pp.604-606
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    • 2009
  • The primary dose effects on an insulated gate bipolar transistor (IGBT) irradiated with a $^{60}Co$ gamma-ray source are found in both of the components of the threshold shifting due to oxide charge trapping in the MOS and the reduction of current gain in the bipolar transistor. In this letter, the IGBT macro-model incorporating irradiation is implemented, and the electrical characteristics are analyzed by SPICE simulation and experiments. In addition, the collector current characteristics as a function of gate emitter voltage, VGE, are compared with the model considering the radiation damage of different doses under positive biases.

퍼지신경망에 의한 퍼지 회귀분석: 품질 평가 문제에의 응용

  • 권기택
    • 한국정보시스템학회:학술대회논문집
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    • 한국정보시스템학회 1996년도 추계학술발표회 발표논문집
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    • pp.211-216
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    • 1996
  • This paper propose a fuzzy regression method using fuzzy neural networks when a membership value is attached to each input-output pair. First, an architecture o fuzzy neural networks with fuzzy weights and fuzzy biases is shown. Next, a cost function is defined using the fuzzy output from the fuzzy neural network and the corresponding target output with a membership value. A learning algorithm is derived from the cost function. The derived learning algorithm trains the fuzzy neural network so 솜 t the level set of the fuzzy output includes the target output. Last, the proposed method is applied to the quality evaluation problem of injection molding

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Rabi pedestal shifts를 이용한 원자시계의 주파수 편이 계산 (Estimation of the frequency biases in an atomic clock by measuring Rabi Pedestal shifts)

  • 박영호;오차환;김필수;김중복;권택용;이호성
    • 한국광학회:학술대회논문집
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    • 한국광학회 2002년도 하계학술발표회
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    • pp.18-19
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    • 2002
  • 1950년 Norman Ramsy는 시간적으로 분리된 두 진동 자장을 사용한 마이크로파 전이 방법을 개발했다 이 방법을 사용할 경우 그림1과 같이 넓은 선폭을 가지는 공진선 ("Rabi pedestal") 위에 좁은 선폭의 분광 신호("Ramsey fringe")를 얻을 수 있다. 램지 방법은 정밀한 분광 측정에 많이 사용되고 있으며, 특히 원자 시계를 구현하기 위한 기본 기술이 되고 있다. (중략)

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