• 대한기계학회논문집B
• /
• 제20권2호
• /
• pp.641-648
• /
• 1996

Thermophoretic particle deposition on a circular cylinder in a uniform laminar air flow was numerically investigated using a control volume method based on the generalized non-orthogonal coordinate system. Variation of air properties due to the change of temperature was taken into account. Effects of variable property on the distribution of heat transfer and deposition rates of particle were discussed. A new correlation of thermophoretic particle deposition on a circular cylinder was proposed in the present study.

• 대한수학회보
• /
• 제58권1호
• /
• pp.205-215
• /
• 2021

In [1], Beznosova proved that the bound on the norm of the dyadic paraproduct with b ∈ BMO in the weighted Lebesgue space L2(w) depends linearly on the Ad2 characteristic of the weight w and extrapolated the result to the Lp(w) case. In this paper, we provide the weighted norm estimates of the dyadic paraproduct πb with b ∈ VMO and reduce the dependence of the Ad2 characteristic to 1/2 by using the property that for b ∈ VMO its mean oscillations are vanishing in certain cases. Using this result we also reduce the quadratic bound for the commutators of the Calderón-Zygmund operator [b, T] to 3/2.

• 대한수학회보
• /
• 제58권2호
• /
• pp.419-431
• /
• 2021

In this paper we discuss the classical problem of finding conditions on the entire coefficients A(z) and B(z) guaranteeing that all nontrivial solutions of f" + A(z)f' + B(z)f = 0 are of infinite order. We assume A(z) is an entire function of completely regular growth and B(z) satisfies three different conditions, then we obtain three results respectively. The three conditions are (1) B(z) has a dynamical property with a multiply connected Fatou component, (2) B(z) satisfies T(r, B) ~ log M(r, B) outside a set of finite logarithmic measure, (3) B(z) is extremal for Denjoy's conjecture.

• 디지털융복합연구
• /
• 제2권1호
• /
• pp.93-112
• /
• 2004

A license under UCITA(Uniform Computer Information Transactions Act) which represents the first comprehensive uniform computer information licensing law is not fundamentally rooted in intellectual property law such as patent or copyright law. A license under UCITA is simply a commercial contract, dependent wholly on the parties' ability to enter into a normal, commercial contract, just as a contract of sale or lease is simply and wholly a commercial contract. However, intellectual property rights may be licensed in a contract subject to UCITA. UCITA may not be used to vary or extend informational rights that are intellectual property rights, and expressly recognizes preemption by copyright, patent, or other federal intellectual property law in Section 105(b). Like the law of sales and leases, in general, the right to contract is constrained by principles of unconscionability, good faith and fair dealing, UCITA has an additional restraint, an express power for a court to deny enforcement of a provision in a licensing contract that violates fundamental public policy. This public policy defense is unique in UCITA. An essential purpose of this defense is to give courts some latitude in reconciling commercial licensing law with the principles of intellectual property law. Most intellectual property law is federal, and UCITA expressly recognizes the preemptive effect of that federal law. But the public policy defense gives courts an additional power to consider intellectual property principles purely within the context commercial law.

• Elastomers and Composites
• /
• 제50권3호
• /
• pp.184-188
• /
• 2015

There is a need for light weight and high stiffness characteristics in the building structure as well as aircraft and cars. So fiber reinforced plastic with the addition of reinforcing agent such as glass fiber, carbon fiber, aramid fiber is utilized in this regard. In this study, mechanical strength, flow property and part shrinkage of glass fiber and carbon fiber reinforced PA6 were examined according to reinforcement content such as 10%, 20%, and 30%, and reinforcement type. The mechanical property was measured by a tensile test with specimen fabricated by injection molding and the flow property was measured by spiral test. In addition, we measured the part shrinkage of fiber reinforced PA6 that affects part quality. As glass fiber content increases, mechanical property increased by 75.4 to 182%, and flow property decreased by 18.9 to 39.5%. And part shrinkage decreased by 52.9 to 60.8% in the flow direction, and decreased by 48.2 to 58.1% in the perpendicular to the flow direction. As carbon fiber content increases, mechanical property increased by 180 to 276%, flow property decreased by 26.8 to 42.8%, and part shrinkage decreased by 65.0 to 71.8% and 69.5 to 72.7% in the flow direction and the direction perpendicular to the flow respectively.

• 한국재료학회지
• /
• 제14권9호
• /
• pp.659-663
• /
• 2004

Magnetite was prepared by wet method and oil-based magnetic fluid also was prepared by its magnetite. Ahead of making magnetite, we investigated the variation of physical properties for changing $Fe^{3+}/Fe^{2+}$. Through the variation of the process mixing time, pH, magnetite content, we made magnetic fluid of magnetite. We examined the magnetic and frequency property by a toroidal mold. In result $Fe^{3+}/Fe^{2+}=1.2$, over the minute mixing time property of magnetite, Ms was 61.98 emu/g. Moreover, the B-H loop result indicated that the magnetic fluid followed paramagnetic behavior.

• 한국결정성장학회지
• /
• 제33권5호
• /
• pp.187-190
• /
• 2023

본 연구에서는 ZnO-Na₂O-B₂O₃-SiO₂ 계 유리에 CaO의 첨가에 따른 유리의 열적, 화학적 특성, 표면 제타전위 및 항균특성을 분석하였다. 유리 조성에 따른 열적 특성은 DTA 분석을 통해 확인하였고, 30ZnO-xCaO-20Na₂O-30B₂O₃-(20-x)SiO₂ (x = 0, 2, 4, 6, 8, 10 mol%)계 유리에서 CaO 함량이 증가함에 따라 유리전이온도가 줄어드는 것을 확인하였다. CaO 함량이 늘어날수록 유리 구조가 약화됨에 따라 더 많은 Zn²⁺ 이온이 용출되었고, 알칼리 및 알칼리 토류의 초기 급속한 용출로 인해 유리의 표면 제타전위가 증가함을 확인하였다. 이러한 이유로 유리의 항균활성 또한 급격하게 개선됨을 확인하였으며, 대장균(gram negative)과 황색포도상구균(gram positive) 모두에 대해 99.9 % 항균 활성을 갖는 항균 유리를 개발할 수 있었다.

• Journal of applied mathematics & informatics
• /
• 제27권5_6호
• /
• pp.1493-1499
• /
• 2009

Let $A_1$ and $A_2$ be nonzero complex idempotent and tripotent matrix, respectively. Denote a linear combination of the two matrices by A = $c_1A_1$ + $c_2A_2$, where $c_1,\;c_2$ are nonzero complex scalars. In this paper, under an assumption of $A_1A_2$ = $A_2A_1$, we characterize all situations in which the linear combination is tripotent. A statistical interpretation of this tripotent problem is also pointed out. Moreover, In [2], Baksalary characterized all situations in which the above linear combination is idem-potent by using the property of decomposition of a tripotent matrix, i.e. if $A_2$ is tripotent, then $A_2$ = $B_1-B_2$, where $B^2_i=B_i$, i = 1, 2 and $B_1B_2=B_2B_1=0$. While in this paper, by utilizing a method different from the one used by Baksalary in [2], we prove the theorem 1 in [2] again.

• 한국토양비료학회지
• /
• 제29권1호
• /
• pp.60-66
• /
• 1996

콩 근류균(根瘤菌) B. japonicum의 취락형태(聚落形態)에 따라 항생제반응(抗生劑反應)과 혈청형(血淸型) 및 단백질(蛋白質) 전기영동(電氣泳動) 유형(類型)에 차이가 있을지 여부를 구명(究明)코자 우리나라 남부지방에 분포한 토착근류균(土着根瘤菌)을 대상으로 시험한 결과는 다음과 같았다. 1. 분리(分離)한 B. japonicum 120균주(菌株) 취락형태별(聚落形態別) 분포(分布)는 "Dry"형이 47%, "Wet"형이 41%, "Dry/Wet"형이 12%였다. 2. 항생제(抗生劑) 반응(反應)에 있어서 "Dry"형의 균주(菌株)는 chlorampenicole(200ug/ml)과 kanamycin(20ug/ml)에 대하여. "Wet"형은 erythromycin(100ug/ml)과 nalidixic acid(20ug/ml), spectinomycin sulphate(100ug/ml), streptomycin sulphate(10ug/ml), tetracycline(100ug/ml)에 대하여 각각(各各) 높은 내성(耐性)을 보였다. 3. B. japonicum의 취락형태별(聚落形態別)로는 혈청형(血淸型)의 구분(區分)을 보이지 않았으나, 각 혈청형(血淸型)에 속하는 균주중(菌株中)에는 혈청모균주(血淸母菌株)와 동일한 취락형태(聚落形態)를 가진 것이 많았다. 4. B. japonicum의 혈청학적(血淸學的) 분류결과(分類結果)는 단백질전기영동상(蛋白質電氣泳動上)의 밴드유형과 같았으며 특히, 복잡성(複雜性)에 있어서는 가장 복잡하였던 항생제반응(抗生劑反應) 유형(類型)과 지나치게 단순하였던 취락형태적(聚落形態的) 구분이 중간정도(中間程度)를 나타내어 실용성(實用性)을 보였다. 5. B. japonicum의 취락형태별(聚落形態別) 특성은 항생제반응(抗生劑反應)에서는 특이적(特異的)이었으나 혈청학적(血淸學的) 특성(特性) 및 단백질(蛋白質) 전기영동(電氣泳動) 유형(類型)에서는 다양(多樣)한 경향이었다.

• 대한수학회보
• /
• 제42권2호
• /
• pp.387-396
• /
• 2005

In the setting of the half-plane of the complex plane, we introduce a modified reproducing kernel and we show that for $r>-1/2,\;B^{1,r}-cancellation$ property holds and the Bloch space is the dual space of $B^{1,r}$.