• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.52.3-52.3
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• 2021

Timing analysis에서 pulsar 또는 magnetar의 pulsation 측정은 background 또는 주변의 다른 source의 영향으로 매우 세밀하게 측정을 진행해야 할 수 있다. 하지만 gamma-ray 영역에서는 instrument의 낮은 imaging resolution으로 인해 likeihood 분석법을 사용하며, pulsation측정의 sensitivity를 향상시키기 위해 weighted H-test를 적용하고 있다. weighted H-test는 Instrument의 responses와 source, background의 radiational properties를 이용하여 각 photon의 probability를 계산하고 이를 weight하여 pulsation detection의 sensitivity를 향상시키는 방법으로 이번 연구를 통해 이를 X-ray에서 적용할 수 있도록 확장하였다. 이번 발표에서는 X-ray 데이터 중 상대적으로 낮은 imaging resolution을 갖는 XMM-Newton data에 weighted H-test를 적용하여 기존의 H-test와의 차이를 비교해보고, weighted H-test가 갖는 이점에 대하여 논의하고자 한다.

• Korean Journal of Cognitive Science
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• v.15 no.4
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• pp.21-30
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• 2004

Additive color mixture of two different background colors appeared in the afterimage of a gray circle centered on an isoluminant bichromatic background (red/green, blue/green, or blue/yellow background). The chromatic mixture still appeared in the afterimage of a gray circle on a bichromatic background at different luminance levels, and also appeared in a large test field. The saturation of the induced color was observed to increase as the overall luminance of adaptation background stimulus increase of the size of test field decreases. It was found that the chromatic mixture does not appear with a chromatic or achromatic boundary inserted on the center of the test field. The boundary seems to prevent the induced color on each side of test field from spreading to the other side so that the induced color does not appear mixed but divided into two different colors. Without a boundary on the test stimulus, the color information induced in the afterimage seems to be too weak to create a subjective boundary between the two colors and consequently propagate inward appearing mixed.

• English Language & Literature Teaching
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• v.9 no.2
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• pp.213-241
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• 2003

As an attempt to characterize the English test section of CSAT (College Scholastic Ability Test) and to get some suggestions, this study raised the research questions, as 'What are the main factors that affect students' English test scores in CSAT, and how big influences do they have?' It has been hypothesized that among main factors are the L1 competence, represented by the Korean test scores in CSAT, background knowledge or intelligence, represented by the "total" scores in CSAT, and the two types of L2 knowledge (vocabulary and grammar on one hand and prosody m the other hand), measured by the test devised specially for this study. The individual effect of the L2 vocabulary and grammar (one kind of L2 knowledge) was 70%, that of background knowledge or intelligence 61%, that of the L1 competence 50%, and that of the L2 prosody knowledge (the other kind of L2 knowledge) 32%. According to the stepwise regression, the whole effect of these four factors was 74%. The findings suggest that first, although CSAT is based on the top-down model of comprehension, the bottom-up model of learning should be more emphasized in our English class. Also, since background knowledge or intelligence is the second most influential factor, the top-down model of learning that helps students learn to understand by activating their various schemata must also be very effective.

• Nuclear Engineering and Technology
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• v.25 no.3
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• pp.361-370
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• 1993

Low power physics tests should be peformed for the domestic pressurized light water reactors (PWRs) after refueling. The tests are peformed to ensure that operating characteristics of the core are consistent with predictions and that the core can be operated as designed. But in some low power physics tests, slow but steady reactivity increasing phenomena were noticed after step reactivity insertion by the control rod movement. These reactivity increasing phenomena are due to the low flux level and the gamma background because an uncompensated ion chamber (UIC) is used as the ex-core neutron detector. The gamma background may affect the results or the lour power physics tests. The aims or this paper are to analyze the grounds of such phenomena, to simulate a reference bank worth measurement test and to present a resolution quantitatively. In this study, the gamma background level was estimated by numerically solving the point kinetics equations accounting the gamma background effect. The reactivity computer check test was simulated to verify the model. Also, an appropriate neutron flux level was determined by simulating the reference bank worth measurement test. The determined neutron flux level is approximately 0.3 of the nuclear heating flux. This level is about 3 times as high as the current test upper limit specified in the test procedure. Then, the findings from this work were successfully applied to Kori unit 4 cycle 7 and Yonggwang unit 1 cycle 7 physics tests.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.10
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• pp.104-111
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• 1997

It is known as a difficult problem to recognize text-background mixed documents. In this paper a new string extraction algorithm, using mathematical morphology for the document consisting of text and overlapped periodic background pattern, is proposed. The algorithm consists of pattern periodicity feature extraction and background removal. The extracted pattern periodicity feature is used to determine the shape of structuring elements for morphological pre- and post-processing to remove background. The effectiveness of the proposed algorithm over the existing one is also verified through the experiments with various test documents.

• The Korean Nurse
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• v.24 no.2 s.130
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• pp.54-71
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• 1985

This Study was done in order to identify the relationship between personality traits and home background. As a tool for this purpose, a test for home background diagnosis and personality traits was used with 222 students of a junior nursing college. The s

• Communications for Statistical Applications and Methods
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• v.9 no.3
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• pp.765-774
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• 2002

Suppose one is given a vector X of a finite set of quantities $X_i$ which are independent Poisson random variables. A null hypothesis $H_0$ about E(X) is to be tested against an alternative hypothesis $H_1$. A quantity $\sum\limits_{i}w_ix_i$ is to be computed and used for the test. The optimal values of $W_i$ are calculated for three cases: (1) signal to noise ratio is used in the test, (2) normal approximations with unequal variances to the Poisson distributions are used in the test, and (3) the Poisson distribution itself is used. The above three cases are considered to the situations that are without background noise and with background noise. A comparison is made of the optimal values of $W_i$ in the three cases for both situations.

• Korean Journal of Culture and Social Issue
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• v.20 no.4
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• pp.347-364
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• 2014

The present study was conducted to investigate how emotional expression change, test delay, and background influence on face recognition. In experiment 1, participants were presented with negative faces at study phase and administered for standard old-new recognition test including targets of negative and neutral expression for the same faces. In experiment 2, participants were studied negative faces and tested by old-new face recognition test with targets of negative and positive faces. In experiment 3, participants were presented with neutral faces at study phase and had to identify the same faces with no regard for negative and neutral expression at face recognition test. In all three experiments, participants were assigned into either immediate test or delay test, and target faces were presented in both white and black background. Results of experiments 1 and 2 indicated higher rates for negative faces than neutral or positive faces. Facial expression consistency enhanced face recognition memory. In experiment 3, the superiority of facial expression consistency were demonstrated by higher rates for neutral faces at recognition test. If facial expressions were consistent across encoding and retrieval, memory performance on face recognition were enhanced in all three experiments. And the effect of facial expression change have different effects on background conditions. The findings suggest that facial expression change make face identification hard, and time and background also affect on face recognition.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.293-294
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• 2009

The spectral responsivity of solar cells has been measured under high background irradiance using an LED-based differential spectral responsivity Comparator (DSR-C). The comparator developed is fully automated and has some advantages: It does not need a chopper to modulate the light. Unlike the conventional method, it does not require a monochromator to select wavelength. It covers a wavelength range up to 1200 nm. The wavelength range of the comparator is limited by the spectral power distribution of the LEDs and the spectral responsivity of the standard detector. An active temperature control was utilized to meet the specified standard conditions of solar cell test. This work shows the effect of different levels of background irradiance on the spectral responsivity and the importance of same background irradiance for solar cell test as specified by the corresponding standard.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.17-24
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• 2015

In this paper, we propose a method to solve ghosting problem. To generate adaptive background, using an exponentially decreasing number of frames, may improve object detection performance. To extract moving objects from the background by using a differential image, detection error may be caused by object rotations or environmental changes. A ghosting problem can be issue-driven when there are outdoor environmental changes and moving objects. We studied that a differential image by adaptive background may reduce the ghosting problem. In experimental results, we test that our method can solve the ghosting problem.