• 대한수학회지
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• 제46권6호
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• pp.1151-1164
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• 2009

Let E be a reflexive Banach space with a weakly sequentially continuous duality mapping, C be a nonempty closed convex subset of E, f : C $\rightarrow$C a contractive mapping (or a weakly contractive mapping), and T : C $\rightarrow$ C a nonexpansive mapping with the fixed point set F(T) ${\neq}{\emptyset}$. Let {$x_n$} be generated by a new composite iterative scheme: $y_n={\lambda}_nf(x_n)+(1-{\lambda}_n)Tx_n$, $x_{n+1}=(1-{\beta}_n)y_n+{\beta}_nTy_n$, ($n{\geq}0$). It is proved that {$x_n$} converges strongly to a point in F(T), which is a solution of certain variational inequality provided the sequence {$\lambda_n$} $\subset$ (0, 1) satisfies $lim_{n{\rightarrow}{\infty}}{\lambda}_n$ = 0 and $\sum_{n=0}^{\infty}{\lambda}_n={\infty}$, {$\beta_n$} $\subset$ [0, a) for some 0 < a < 1 and the sequence {$x_n$} is asymptotically regular.

• Journal of Power Electronics
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• 제13권5호
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• pp.806-813
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• 2013

This paper aims to compare the performance of three phase induction motor drives using Five Leg Inverter (FLI) and Three Leg Inverter (TLI) configurations. An Indirect Field Oriented Control (IFOC) method using a TLI is well established and incorporated for high performance speed drives in various industries. The FLI dual motor drive system on the other hand shows good workability in the independent control of two induction motor drives simultaneously. In this experiment, the IFOC method is utilized for both drive systems, and Space Vector Pulse Width Modulation (SVPWM) is used to generate pulses for both inverters. For the FLI, the Double Zero Sequence (DZS) Injection technique is used to generate the modulation signal. The complete experiment setup is done by using a DSpace 1103 controller board. The individual motor performances are analyzed using similar schemes, equipment setups and controller parameter values. The results show similar speed performance response capability between the single motor operation using a TLI system and the two motor operation using a FLI system based on the variable speed range either in forward or reverse operation. They also show similar load rejection abilities. However, the single motor with a TLI has a better power quality aspect such as ripple current and total harmonics distortion (THD).

• 산업기술연구
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• 제21권A호
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• pp.167-179
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• 2001

This paper discusses an index-based subsequence matching that supports time warping in large sequence databases. Time warping enables finding sequences with similar patterns even when they are of different lengths. In earlier work, we suggested an efficient method for whole matching under time warping. This method constructs a multidimensional index on a set of feature vectors, which are invariant to time warping, from data sequences. For filtering at feature space, it also applies a lower-bound function, which consistently underestimates the time warping distance as well as satisfies the triangular inequality. In this paper, we incorporate the prefix-querying approach based on sliding windows into the earlier approach. For indexing, we extract a feature vector from every subsequence inside a sliding window and construct a multi-dimensional index using a feature vector as indexing attributes. For query precessing, we perform a series of index searches using the feature vectors of qualifying query prefixes. Our approach provides effective and scalable subsequence matching even with a large volume of a database. We also prove that our approach does not incur false dismissal. To verily the superiority of our method, we perform extensive experiments. The results reseal that our method achieves significant speedup with real-world S&P 500 stock data and with very large synthetic data.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.274-279
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• 2004

Currently, carbon-fiber reinforced plastics(CFRP) are widely used in both space and civil aircraft due to their superior stiffness and strength to weight ratios compared to conventional metallic materials. This paper is to study the effects of curvature and stacking sequence on the penetration characteristics of composite laminated shell. And were performed to investigate the penetration characteristics of composite laminated shells by the oblique impact. They are stacked to [0$_3$/90$_3$]s, [90$_3$/0$_3$]s and [0$_2$/90$_3$/0]s, [90$_2$/0$_3$/90]s their interlaminar number two and fore. They are manufactured to varied curvature radius (R=100, 150, 200mm and $\infty$). When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determining the time for it to pass two ballistics-screen sensor located a known distance apart. In general, the critical penetration energy interface decrease and slope angle on the impact surface increased. [0$_3$/90$_3$]s and [0$_2$/90$_3$]s specimens higher than [90$_3$/0$_3$]s and [90$_2$/0$_3$/90]s specimens.

• 한국CDE학회논문집
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• 제20권4호
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• pp.367-374
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• 2015

Sandwich panels consisting of various materials have widely been applied for mitigating dynamic impacts such as ballistic and blast impacts. Especially, the selection of materials for different core set-ups can directly influence its performance. In this study, we design the sandwich panels for alleviating ballistic and blast impacts by controlling the stacking sequence of core materials and their thicknesses. FEM studies are performed to simulate the dynamic behavior of sandwich panels subjected to ballistic and blast impacts. Delamination between the core layers is also considered in the FEM studies for feasible design. Based on the FEM data, kriging models are generated for approximating design space and quickly predicting the FEM outputs. Finally, design optimizations are implemented to find the optimum stacking sequence of core materials and thicknesses with given impact situations.

• 한국가금학회지
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• 제44권2호
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• pp.103-111
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• 2017

The quail (Coturnix japonica) has been used as a model animal in many research fields and its application is still expanding in other fields. Compared to the chicken, the quail is quicker to reach sexually maturity, has short generation intervals, is easy to handle, requires less space and feed, and is sturdy. In addition, it produces many eggs and the research tools developed for chicken can be applied directly to quail or with some modifications. Due to recent advances in next-generation sequencing, abundant sequence data for the quail genome and transcripts have been generated. These sequence data are valuable sources for studying functional genomics using quail, which is one of the model animal used to investigate gene function and networks. Although there are some obstacles to be removed, the quail is the best optimized model to study the functional genomics of poultry. In many research fields, functional genomics study using the quail model will provide the best opportunity to understand the phenomena and principles of life. We review why, among many other birds, the quail is the best model for studying poultry functional genomics.

• Communications for Statistical Applications and Methods
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• 제18권6호
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• pp.799-808
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• 2011

Let {${\Omega}$, $\mathcal{F}$, P} be a probability space and {$X_n{\mid}n{\geq}1$} be a sequence of random variables defined on it. A finite sequence of random variables {$X_i{\mid}1{\leq}i{\leq}n$} is a conditional associated given $\mathcal{F}$ if for any coordinate-wise nondecreasing functions f and g defined on $R^n$, $Cov^{\mathcal{F}}$ (f($X_1$, ${\ldots}$, $X_n$), g($X_1$, ${\ldots}$, $X_n$)) ${\geq}$ 0 a.s. whenever the conditional covariance exists. We obtain the H$\grave{a}$jek-R$\grave{e}$nyi-type inequality for conditional associated random variables. In addition, we establish the strong law of large numbers, the three series theorem, integrability of supremum, and a strong growth rate for $\mathcal{F}$-associated random variables.

• 한국균학회지
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• 제40권3호
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• pp.174-176
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• 2012

본 연구에서는 아직까지 한국 진균 학술지에 보고되어 있지 않은 6종의 새로운 효모들의 형태학적, 생리학적 특성에 대하여 보고한다. 이들 효모들은 한국의 대전시에 서식하고 있는 야생화들로부터 분리해서 ITS-2 또는 18S rDNA 염기서열의 분자생물학적 분석 방법을 이용 동정하였다. 이들 6종의 새로운 국내 미기록 효모들은 Kuraishia capsulate, Lodderomyces elongisporus, Pseudozyma antarctica, Starmerella bombicola으로 분리되었다.

• 스마트미디어저널
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• 제8권2호
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• pp.74-79
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• 2019

기존의 복합명사 분해 알고리즘은 미등록어 단위명사들이 포함된 복합명사를 분해할 때 미등록어를 분리하기 어려운 문제가 발생한다. 이는 현실적으로 모든 고유명사, 신조어, 외래어 등의 모든 단위 명사를 사전에 등록하는 것은 불가능하다는 한계가 존재하기 때문이다. 이 문제를 해결하기 위하여 복합명사 분해 문제를 태그 열 부착(sequence labeling) 문제로 정의하고 음절 단위 임베딩과 딥러닝 기법을 이용하는 복합명사 분해 방법을 제안한다. 단위명사 사전을 구축하지 않고 미등록 단위명사를 인식하기 위하여 복합명사를 구성하는 각 음절들을 연속적인 벡터 공간에 표현하여 LSTM과 선형체인(linear-chain) CRF를 이용하는 방식으로 복합명사를 단위명사들로 분해한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.2908-2924
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• 2019

Multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is widely applied in wireless communication by virtue of its excellent properties in data transmission rate and transmission accuracy. However, as a major drawback of MIMO-OFDM systems, the high peak-to-average power ratio (PAPR) complicates the design of the power amplifier at the receiver end. Some available PAPR reduction methods such as selective mapping (SLM) suffer from high computational complexity. In this paper, a low-complexity SLM method based on active constellation extension (ACE) and joint space-time selective mapping (AST-SLM) for reducing PAPR in Alamouti STBC MIMO-OFDM systems is proposed. In SLM scheme, two IFFT operations are required for obtaining each transmission sequence pair, and the selected phase vector is transmitted as side information(SI). However, in the proposed AST-SLM method, only a few IFFT operations are required for generating all the transmission sequence pairs. The complexity of AST-SLM is at least 86% less than SLM. In addition, the SI needed in AST-SLM is at least 92.1% less than SLM by using the presented blind detection scheme to estimate SI. We show, analytically and with simulations, that AST-SLM can achieve significant performance of PAPR reduction and close performance of bit error rate (BER) compared to SLM scheme.