• 한국수학교육학회지시리즈E:수학교육논문집
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• 제24권1호
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• pp.49-65
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• 2010

본 연구는 함수의 개념정의와 개념이미지 형성을 위한 다양한 표상에서 정의역을 고려한 지도-학습을 권고하고자 함에 있다. 중학교 1학년 및 2학년의 수학 교과서에서 함수나 일차함수 개념을 도입하거나 이들 함수의 활용을 학습하는 데 탐구형 문제나 현실적 모델을 가져오고 이 모델로부터 표를 만들기도 하고 함수관계식을 찾게 한 다음 그래프를 그리게 하는 일련의 표상과 표상의 번역과정을 연습한다. 본 연구는 이러한 표상활동에서 일어나는 모델의 적절성과 표현의 적절성을 표상의 동치성과 정의역에 초점을 두어 논한다. 특히 일차함수의 활용에서 교과서에 제시된 휴대폰 요금문제나 저축문제 등에서 일차함수의 식과 그래프로 모델링하는 과정에 나타난 문제점을 비판적으로 검토하고 정의역의 중요성을 지적한다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제12권1호
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• pp.41-53
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• 2008

Polynomials are one of most important and widely used numerical tools in dealing with a smooth function on a bounded domain and trigonometric functions work for smooth periodic functions. However, they are not the best choice if a function has a bounded support in space and in frequency domain. The Prolate Spheroidal wave function (PSWF) of order zero has been known as a best candidate as a basis for band-limited functions. In this paper, we review some basic properties of PSWFs defined as eigenfunctions of bounded Fourier transformation. We also propose numerical inversion schemes based on PSWF and present some numerical examples to show their feasibilities as signal processing tools.

• 대한전기학회논문지
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• 제31권8호
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• pp.33-38
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• 1982

This paper deals with the simplification of the transfer function in a frequency domain, viz. the integral of the squared errors between the original and the simplified model is minimized and the latter is estimated by the Walsh function. It tries to minimize the errors between the frequency responses of the two functions. This method is compared with the existing method by means of a numercal example. The frequency response of this simplified model approximates closely to that of the original model. The proposed method is simpler in analysis and easier in implementation than the existing methods. Though the Walsh function can be easily generated with the discrete values, it has errors because its zero crossings are not continuous. This method aims at the reduction of the errors in the real parts and the imaginary parts of the two functions by dividing into the more sub-intervals, and selecting the reduced-order model according to the response of the model. As a result, it can be applied for the simplification of higher order functions into lower order functions and for the design of control systems.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.169-170
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• 2009

We present a quantification protocol to get the alignment factors of a custom-made spectrometer and the nonlinear fitting function between the measured CCD pixel domain and the wavelength domain to apply the spectral-domain optical coherence tomography using fiber Bragg gratings. We have used 4 different center wavelength gratings with a narrow spectral bandwidth (<0.05 nm) and the same reflectivity (>92 %) to calibrate and align the custom-made spectrometer.

• Journal of applied mathematics & informatics
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• 제36권5_6호
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• pp.349-358
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• 2018

In this article, we discuss the domain of attraction of HIV-1 system by using the moment theory. First, the asymptotic stabilities of the equilibrium point of the system are given, and then we introduce how to use the moment method to estimate domain of attraction. Finally, one simulation shows the effectiveness of moment method.

• 한국자기공명학회논문지
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• 제12권1호
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• pp.1-13
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• 2008

Acetyl-CoA carboxylase (ACC) catalyzes the first step in fatty acid biosynthesis: the synthesis of malonyl-CoA from acetyl-CoA. As essential regulators of fatty acid biosynthesis and metabolism, ACCs are regarded as therapeutic targets for the treatment of metabolic diseases such as obesity, In ACC, the biotinoyl domain performs a critical function by transferring an activated carboxyl group from the biotin carboxylase domain to the carboxyl transferase domain, followed by carboxyl transfer to malonyl-CoA. Despite the intensive research on this enzyme, only the bacterial and yeast ACC structures are currently available, To explore the mechanism of ACC holoenzyme function, we determined the structure of the biotinoyl domain of human ACC2 and analyze its characteristics using NMR spectroscopy. The 3D structure of the hACC2 biotinoyl domain has a similar folding topology to the previously determined domains from E. coli and P. Shermanii, however, the 'thumb' structure is absent in the hACC2 biotinoyl domain. Observations of the NMR signals upon the biotinylation indicate that the biotin group of hACC2 does not affect the structure of the biotinoyl domain, while the biotin group for E. coli ACC interacts directly with the thumb residues that are not present in the hACC2 structure. These results imply that, in the E. coli ACC reaction, the biotin moiety carrying the carboxyl group from BC to CT can pause at the thumb of the BCCP domain. The human biotinoyl domain, however, lacks the thumb structure and does not have additional non-covalent interactions with the biotin moiety; thus, the flexible motion of the biotinylated lysine residue must underlie the "swinging arm" motion. This study provides insight into the mechanism of ACC holoenzyme function and supports the "swinging arm" model in human ACCs.

• 대한의생명과학회지
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• 제20권2호
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• pp.49-55
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• 2014

RalBP1 is an ATP-dependent non-ABC transporter, responsible for the major transport function in many cells including many cancer cell lines, causing efflux of glutathione-electrophile conjugates of both endogenous metabolites and environmental toxins. RalBP1 is expressed in most human tissues, and is over-expressed in non-small cell lung cancer cell lines and in many other tumor types. Blockade of RalBP1 by various approaches has been shown to increase sensitivity to radiation and chemotherapeutic drugs, leading to cell apoptosis. In xenograft tumor models in mice, RalBP1 blockade or depletion results in complete and sustained regression across many cancer cell types including lung cancer cells. In addition to its transport function, RalBP1 has many other cellular and physiological functions, based on its domain structure which includes a unique Ral-binding domain and a RhoGAP catalytic domain, as well as docking sites for multiple signaling proteins. Additionally, RalBP1 is also important for stromal cell function in tumors, as it was recently shown to be required for efficient endothelial cell function and angiogenesis in solid tumors. In this review, we discuss the cellular and physiological functions of RalBP1 in normal and lung cancer cells.

• 대한한의학회지
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• 제22권4호
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• pp.131-141
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• 2001

Objectives : Asthma is a chronic inflammatory disorder in which the airway smooth muscle undergoes exaggerated constriction and is abnormally responsive to external stimuli and clinically manifests dyspnea, cough, and wheezing. Recently in Korea, the number of asthma patients has tended to increase as air pollution increases and new allergens appear. This study aimed to identify the therapeutic effects of Sochongryong-tang, which has been used on asthmatic patients in Oriental Medicine for a long time. Methods : We studied 10 asthmatic patients who had visited the Division of Respiratory System, Department of Internal Medicine of Kyunghee Oriental Medical Center from February 1, 2001 to June 30, 2001, which examined the patients by the pulmonary function test (PFT) and Quality of Life Questionnaire for adult Korean Asthmatics (QLQAKA) before and after taking Sochongryong-tang for two weeks. The data was analyzed using paired t-test. Results : After treatment with Sochongryong-tang for two weeks, FEV 1.0 showed a significant increase of 14.2%, FVC a significant increase of 9.3% and PEFR a significant increase of 16.2% in results of patients examined asthmatic by PFT. In the results of QLQAKA, the mean of scores increased significantly over 0.5 points in total score, symptom domain, emotion domain, and environmental domain. Conclusions : This study shows that Sochongryong-tang has the effect of improvements of pulmonary function and quality of life in asthmatic patients.

• 한국철도학회논문집
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• 제14권6호
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• pp.495-500
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• 2011

철도차량의 승차감은 승객이 느끼는 감정이므로 물리적인 진동의 크기뿐만 아니라 인간의 감응도(느낌)도 고려하여야 하며, 이러한 진동에 대한 인간의 감응도를 나타낸 것이 주파수 보정곡선이다. 주파수 보정곡선은 라플라스 변환형태의 전달함수이기 때문에 이 전달함수를 직접 사용하여 시간 영역에서의 승차감의 평가가 불가능하다. 이를 해결하기 위해서 본 논문에서는 라플라스 변환형태의 전달함수를 시간 영역에서 사용할 수 있는 전달함수로 변환하는 방법을 제시하고 다양한 예제를 통해 이 방법에 대한 타당성을 입증하였다.

• 음성과학
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• 제9권2호
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• pp.13-23
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• 2002

This study examines the effect of laryngeal consonants of Korean on prosodic domain-initial strengthening. Keating, Cho, Fougeron & Hsu (1999), Fougeron & Keating (1996), and Hsu & Jun (1998) found that consonants at the beginnings of larger phrases are more constricted than consonants at the beginnings of smaller phrases. Korean laryngeal consonants pose a counter-example to the general pattern of domain-initial strengthening since tense and aspirated consonants are longer word-medially than word-initially. Previous work on domain-initial strengthening focused on domain-initial consonants at different prosodic domains. This study shows that acoustic cues that are not domain-edge also function to demarcate prosodic structure when the domain-initial consonant is laryngeal: VOT for an aspirated consonant and duration of V2 for a tense consonant.