• Journal of applied mathematics & informatics
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• 제33권1_2호
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• pp.229-234
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• 2015

In the setting of semidefinite linear complementarity problems on $S^n$, we focus on the Stein Transformation $S_A(X):=X-AXA^T$ for $A{\in}R^{n{\times}n}$ that is positive semidefinite preserving (i.e., $S_A(S^n_+){\subseteq}S^n_+$) and show that such transformation is strictly monotone if and only if it is nondegenerate. We also show that a positive semidefinite preserving $S_A$ has the Ultra-GUS property if and only if $1{\not\in}{\sigma}(A){\sigma}(A)$.

• 호남수학학술지
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• 제31권4호
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• pp.591-599
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• 2009

For given ${\alpha},{\omega}\;{\in}\;{\mathbb{R}}$ and ${\beta}$ > 1, let $T_{{\beta},{\alpha},{\omega}}$ be the skew-product transformation on the torus, [0, 1) ${\times}$ [0, 1) defined by (x, y) ${\longmapsto}\;({\beta}x,y+{\alpha}x+{\omega})$ (mod 1). In this paper, we give a criterion of ergodicity and weakly mixing for the transformation $T_{{\beta},{\alpha},{\omega}}$ when the natural extension of the given ${\beta}$-transformation can be viewed as a generalized baker's transformation, i.e., they flatten and stretch and then cut and stack a two-dimensional domain. This is a generalization of theorems in [10].

• Archives of Pharmacal Research
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• 제25권6호
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• pp.747-758
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• 2002

The skin displays a highly active metabolism of polyunsaturated fatty acids (PUFA). Dietary deficiency of linoleic acid (LA), an 18-carbon (n-6) PUFA, results in characteristic scaly skin disorder and excessive epidermal water loss. Although arachidonic acid (AA), a 20-carbon (n6) PUFA, is metabolized via cyclooxygenase pathway into predominantly prostaglandin $E_2(PGE_2)$ and $PGF_{2{\alpha}}$, the metabolism of AA via the 15-lipoxygenase (15-LOX) pathway, which is very active in skin epidermis and catalyzes the transformation of M into predominantly 15S-hydroxyeicosatetraenoic acid (15S-HETE). Additionally, the 15-LOX also metabolizes the 18-carbon LA into 13S-hydroxyoctadecadienoic acid (13S-HODE), respectively. Interestingly, 15-LOX catalyzes the transformation of $dihomo-{\gamma}-linolenic$ acid (DGLA), derived from dietary gamma-linolenic acid, to 15S-hydroxyeicosatrienoic acid (15S-HETrE). These monohydroxy fatty acids are incorporated into the membrane inositol phospholipids which undergo hydrolytic cleavage to yield substituted-diacylglycerols such as 13S-HODE-DAG from 13S-HODE and 15S-HETrE-DAG from 15S-HETrE. These substituted-monohydroxy fatty acids seemingly exert anti-inflammatory/antiproliferative effects via the modulation of selective protein kinase C as well as on the upstream/down-stream nuclear MAP-kinase/AP-1/apoptotic signaling events.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2005년도 e-Biz World Conference 2005
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• pp.143-148
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• 2005

The purpose of this paper is to analyze pricing strategies between conventional offline retailers and Internet retailers and discuss which strategy is more profitable when a bricks-and-mortar firm transforms into a clicks-and-mortar firm.

• 한국광학회지
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• 제14권4호
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• pp.473-479
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• 2003

본 연구는 스캔된 이미지의 원본색이 모니터에 그대로 디스플레이 될 수 있게 하는 것을 목적으로 한다. 색보정 과정은 스캐너의 색 특성 묘사를 통한 원본색의 XYZ 추정, 기준 광원의 차이를 고려한 XYZ 변환, XYZ와 RGB간의 색공간 변환으로 구성된다. 특히, XYZ 추정에 있어서 스캐너에 입사되는 빛의 세기와 출력신호간의 비선형적 관계를 두 구간으로 나누어 묘사함으로써 그 정확도를 높였다 EPSON Expression 1680 스캐너를 대상으로 실시한 결과, 228가지 기준색의 기준값과 추정값의 평균 색차는 1.47 $\Delta$ $E_{UV}$ * 이었으며, 36가지의 유채색과 22가지의 무채색으로 구성된 시험색의 평균 색차가 각각 1.51 $\Delta$ $E_{UV}$ * 와 0.90 $\Delta$ $E_{UV}$ * 이었다. 또한 시험색 36가지에 대해 기준값과 추정값으로 부터 산출된 sRGB 모니터 입력신호를 동일 모니터에 디스플레이한 결과, 두 이미지의 색이 동일하게 보였다. sRGB 모니터 입력신호를 동일 모니터에 디스플레이한 결과, 두 이미지의 색이 동일하게 보였다.

• 한국전자거래학회지
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• 제26권4호
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• pp.119-131
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• 2021

플랫폼 비즈니스의 급속한 성장과 함께 디지털 트랜스포메이션은 기업의 가장 중요한 화두로 부상하였으며, 기업에게 있어 더 이상 선택사항이 아닌 생존을 위한 필수전략이 되었다. 많은 기존 기업들은 디지털화를 위하여 필사의 노력을 하고 있다. 관련된 많은 연구들이 있었지만, 아직 대부분 사례 분석들을 통한 개념적 모델 수준의 연구들에 머물고 있다. 본 연구의 목적은 디지털 트랜스포메이션의 기반이 되는 플랫폼 비즈니스 모델을 중심으로 트랜스포메이션을 통해 획득할 효익의 근간이 되는 데이터의 통합 및 증가되는 네트워크 효과의 효익을 학술적, 체계적으로 분석해 보고자 하는 것이다. 플랫폼 기반 변화는 내부의 효율성 강화와 외부적 확장으로 구분할 수 있다. 내부적으로는 기업의 내부 데이터가 결합되고 다시 의사결정 및 실행과 결합되도록 하는 데이터 구조 개선 및 조직의 개선이 필요할 것이며, 외부적으로는 플랫폼 비즈니스 모델 기반 사업 구현으로 보다 많은 소비자의 외부 데이터를 결합, 활용하는 구조를 세워 신사업 개척, 소비자 행동 예측을 위한 가치를 높여야 할 것이다. 디지털 트랜스포메이션이 성숙되지 않은 상황에서, IT인프라가 가장 구조적으로 앞서 있는 금융산업은 가장 먼저 산업적으로 이상을 실현할 수 있는 산업으로 기대되고 있다. 외부 데이터 결합 사업을 위하여 금융 기업들은 다양한 시도들을 하고 있으며, 좋은 결실을 맺는다면 타 산업의 전환성숙에도 공헌할 수 있을 것으로 기대된다. 정책적으로는 정부의 마이데이터 사업 실시에 있어 국가 차원의 데이터 구조, 거래 체계에 대한 논의가 빨리 진행되어야 할 필요성을 제기하였다.

• 열처리공학회지
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• 제13권4호
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• pp.265-271
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• 2000

The microstructural change and transformation characteristics with cooling rate i.e. wheel speed were investigated in 82.8wt%Cu-12.8wt%Al-4.3wt%Ni SMA ribbons fabricated by melt-spinning. The thickness and width of ribbon were decreased with increasing wheel speed, while the uniformity of it was improved. At same wheel speed, the grain size of the contact surface of ribbon was smaller than that of free surface. The mean grain size was decreased with increasing wheel speed, resulted in obtaining grains with $3{\mu}m$ in mean diameter in the wheel speed of 30 m/s. However, micro-voids and cracks at grain boundary could be observed at higher wheel speed. $M_s$ and $A_s$ temperatures were decreased, and $M_s{\sim}M_f$ and $A_s{\sim}A_f$ temperature ranges were broadened with increasing wheel speed. All the ribbons were retained the ordered $D0_3$ due to rapid cooling, the volume fraction of it was increased with increasing wheel speed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.411-414
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• 2005

It is reported that $\varepsilon$ (HCP) and $\gamma$ (FCC) phases of a Fe-17Mn alloy transform to $\alpha'$ phase, which has BCC structure, under a deformation condition. In this study, we investigated the effect of strain-induced-transformed $\alpha'$ phase on sliding wear of the Fe-17Mn alloy that originally had e and y phases. Wear tests of the materials were carried out using a pin-on-disk wear tester at various loads of 0.5N-50N under a constant sliding speed condition of 0.38m/s against glass $(83\%\;SiO_2)$ beads. The sliding distance and radius were loom and 9 mm, respectively. Wear rate of the Fe-17Mn alloy was calculated by dividing the weight loss, measured to the accuracy of $10^{-5}g$ by the measured specific gravity and sliding distance. Worn surface and wear debris of the specimens were examined using an SEM and XRD. During the wear, $\alpha'$ phase of BCC structure was formed by strain-induced transformation when the applied wear load exceeded critical values. The $\alpha'$ phase formed by the strain induced transformation increased the wear rate of the Fe-17Mn alloy.

• Journal of applied mathematics & informatics
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• 제26권3_4호
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• pp.605-614
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• 2008

In this paper, we find the matrix representation of multi-degree reduction by $L_{\infty}$ of $B{\acute{e}}zier$ curves with constraints of endpoints continuity. Using the basis transformation between Chebyshev polynomials and Bernstein polynomials we can derive the matrix representation of multi-degree reduction of $B{\acute{e}}zier$ with respect to $L_{\infty}$ norm.

• 한국주거학회논문집
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• 제9권1호
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• pp.11-19
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• 1998

A transitional trend of architectural elements which would happen naturally in a building may be a cue to the changes of the times. In this respect, this study is to investigate the transformation of types of windows and doors with the full-openable bay size in Korean Buddhist Temples and search for transitional process on types of windows and doors according to the flow of the times. As the results of this study, the following conclusion could be obtained. 1. The type of bunhap(connected door frame) Deul E-Yul-Gae doors + Deul E-Yul-Gas (life up) single windows would be changed from windows of a bay just beside a on the transition that the whole would be altered into the same type. 2. The type of Bunhap (connected door frame)Deul E-Yul-Gae doors + Bunhap (connected door frame) Deul E-Yul-Gae doors would be changed into Bunhap swinging doors that the whole of windows and doors could be opend very easily. 3. The type of Bunhap swinging doors + Bunhap swinging doors would be seen in the transition that windows and doors would be altered separately due to the exchange from window and doors of one of a middle bay or a bay just beside a middle bay to swinging doors and etc.