• Journal of the Korean Mathematical Society
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• v.41 no.5
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• pp.883-894
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• 2004

We discuss in this paper the strong convergence for weighted sums of negative associated (in abbreviation: NA) arrays. Meanwhile, the central limit theorem for weighted sums of NA variables and linear process based on NA variables is also considered. As corollary, we get the results on iid of Li et al. ([10]) in NA setting.

• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.467-478
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• 1999

This paper deals with the problem of change-point estimation where there is one level change in location with iid errors. A change-point estimator using rank average is proposed with the proof of its consistency. A comparison study of various change-point estimators is done by simulation on the mean the proportion and the variance when the errors are from the normal and the double exponential distributions.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.213-214
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• 2008

In this paper, we analyze the performance of a cooperative communication wireless network over independent and identically distributed (IID) Nakagami-m fading channels. A simple transmission scheme is considered where the relay is operating in amplify-forward (AF) mode. A closed-form expression for symbol error rate (SER) is obtained using the moment generating function (MGF) of the total signal to noise ratio (SNR) of the transmitted signal with binary phase shift keying (BPSK).

• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.51-65
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• 2011

In the present paper sufficient conditions, in terms of hyper-geometric inequalities, are found so that the Hohlov operator preserves a certain subclass of close-to-convex functions (denoted by $R^{\tau}$ (A, B)) and transforms the classes consisting of k-uniformly convex functions, k-starlike functions and univalent starlike functions into $\cal{R}^{\tau}$ (A, B).

• Journal of the Korean Statistical Society
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• v.28 no.2
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• pp.151-165
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• 1999

This paper considers the trimmed least squares estimator of the autoregression parameter in the unstable AR(1) model: X\ulcorner=ØX\ulcorner+$\varepsilon$\ulcorner, where $\varepsilon$\ulcorner are iid random variables with mean 0 and variance $\sigma$$^2$> 0, and Ø is the real number with │Ø│=1. The trimmed least squares estimator for Ø is defined in analogy of that of Welsh(1987). The limiting distribution of the trimmed least squares estimator is derived under certain regularity conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.10
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• pp.825-831
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• 2017

Radar clutter in real environment is in general heterogeneous and especially nonstationary if radar geometry is of non-sidelooking monostatic structure or bistatic structure. These clutter properties lead to the insufficient number of secondary data of IID(Independent identically distributed) property, conclusively deteriorate clutter suppression performance. In this paper, we propose a clutter suppression algorithm that estimates the clutter signal belonging to cull under test via calculation using only prior information, rather than using the secondary data. Through analyzing the angle-Doppler spectrum of the clutter signal, we show the estimation of the clutter signal using prior information only is possible and present the derivation of a clutter suppression algorithm through eigen-value analysis. Finally, we show the performance of the proposed algorithm by simulation.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.39-49
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• 1999

The space of IID([ndependently, Identically Distributed) textures was built with axes of mean luminance and contrast, and studied on what kind of mechanisms were required to mediate texture segregation in this space. The conjecture was tested that one of these mechanisms is sensitive to the differences between the means of textures to be discriminated, whereas the other is sensitive to the differences between variances. The probability of discrimination was measured for various pairs of textures in the lID space The data were well fit by a model in which discrimination depends on two mechanisms whose responses are combined by probability summation. The conjecture was rejected that two mechanisms respectively tuned to mean and variance of texture function in segregation. Discrimination within space is mediated by 2 independent channels however: the 2 independent channels are not exactly tuned to texture mean and variance. One m mechanism was primarily sensitive to texture mean, whereas the other was sensitive to b both texture mean and variance.

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.243-248
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• 2017

Background: To evaluate the versatility and reach of modified nasolabial flap used in reconstruction of defects created in and around the oral cavity. Methods: A total number of 20 cases were selected. Out of which 13 were males and 7 females. The age of these patients ranged from 24-63 years. 29 modified nasolabial flaps were raised in twenty patients. Based on clinical and histopathological examination, out of 20 patients, 14 patients were diagnosed with oral submucous fibrosis, 3 with verrucous carcinoma, 1 with squamous papilloma, 1 with oro-antral fistula and 1 with traumatic loss of lower lip. Results: Minimum preoperative interincisal distance (IID) was 0 mm and maximum was 15 mm with mean of $6.00{\pm}4.76mm$ in patients with oral submucous fibrosis and 12 months postoperatively minimum IID was 16 mm and maximum was 41 mm with mean of $28.00{\pm}8.96mm$. In one case, dehiscence (3.4%) was noted on the anterior tip for which tip revision was done. Bulky appearance of the flap intraorally was observed in 2 cases (6.9%). Five (17.2%) among the 29 flaps had visible scar at the donor site postoperatively up to 3 months. Conclusion: Numerous reconstructive techniques have been employed in the reconstruction of small to intermediate sized defects of oral cavity. Modified nasolabial flap is a versatile flap which has robust vascularity and can be successfully used with minimal complications. It can be rotated intraorally to extend from the soft palate to the lip. Thus, it can be used efficiently to treat the small defects of the oral cavity as well as recreating lost lip structure.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.27-40
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• 2022

Medical AI, which has lately made significant advances, is playing a vital role, such as assisting clinicians with diagnosis and decision-making. The field of chest X-rays, in particular, is attracting a lot of attention since it is important for accessibility and identification of chest diseases, as well as the current COVID-19 pandemic. However, despite the vast amount of data, there remains a limit to developing an effective AI model due to a lack of labeled data. A research that used federated learning on chest X-ray data to lessen this difficulty has emerged, although it still has the following limitations. 1) It does not consider the problems that may occur in the Non-IID environment. 2) Even in the federated learning environment, there is still a shortage of labeled data of clients. We propose a method to solve the above problems by using the self-supervised learning model as a global model of federated learning. To that aim, we investigate a self-supervised learning methods suited for federated learning using chest X-ray data and demonstrate the benefits of adopting the self-supervised learning model for federated learning.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.307-309
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• 1999

입체음향이란 음원의 위치에 따라 두 귀에 입력되는 신호를 제어함으로써 시각정보 없이 음상의 위치를 파악할 수 있는 음이다. 헤드폰을 이용하면 음장이 머리 내에 위치하게 됨으로써 거리를 파악하는 것이 매우 힘들다. 본 논문에서는 모노음을 이용하여, 2채널 헤드폰에서 재생할 수 있는 3차원 음을 만들기 위하여 Interaural Time Difference(ITD)와 Interaural Intensity Difference(IID)를 이용한 머리 전달함수(Head Related Transfer Function:HRTF)를 만든 결과와 측정 HRTF 자료인 KEMAR Data를 이용한 결과를 비교하였으며, 거리 효과를 효과적으로 구현하기 위하여 잔향효과를 추가하여 음장을 머리밖으로 꺼냄으로써, 보다 향상된 3차원 음상 제어 시스템을 제안하고 실험하였다.