• East Asian mathematical journal
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• 제38권1호
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• pp.1-12
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• 2022

Let R be a ring with an endomorphism σ and a σ-derivation δ. R is called (σ, δ)-Baer (resp. (σ, δ)-quasi-Baer, (σ, δ)-p.q.-Baer, (σ, δ)-p.p.) if the right annihilator of every right (σ, δ)-set (resp., (σ, δ)-ideal, principal (σ, δ)-ideal, (σ, δ)-element) of R is generated by an idempotent of R. In this paper, for a given Ore extension A = R[x; σ, δ] of R, the following properties are investigated: If R is a σ-rigid ring in which σ and δ commute, then (1) R is (σ, δ)-Baer if and only if R is (σ, δ)-quasi-Baer if and only if A is (${\bar{\sigma}},\;{\bar{\delta}}$)-Baer if and only if A is (${\bar{\sigma}},\;{\bar{\delta}}$)-quasi-Baer; (2) R is (σ, δ)-p.p. if and only if R is (σ, δ)-p.q.-Baer if and only if A is (${\bar{\sigma}},\;{\bar{\delta}}$)-p.p. if and only if A is (${\bar{\sigma}},\;{\bar{\delta}}$)-p.q.-Baer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4451-4456
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• 2016

Background: In this study, we examined epidemiological aspects of dynamic changes in incidences of laryngeal cancer in male and female populations in Kazakhstan. Materials and Methods: Primary data were for registered patients with malignant laryngeal tumors in the whole country during the period of 1999-2014. Evaluation of changes in laryngeal cancer incidence in the population of Kazakhstan was performed using component analysis. Results: It was determined that the number of patients with laryngeal cancer in the whole country is decreasing although with conflicting impacts of different factors. Despite population growth (all - ${\Delta}_P=+66.1%$, men - ${\Delta}_P=+70.9%$ and women - ${\Delta}_P=+46.4%$), and aging (all - ${\Delta}_A=+45.1%$, men - ${\Delta}_A=+54.3$ and women - ${\Delta}_A=+22.2$), the reduction in risk of developing the disease (all - ${\Delta}_R=-165.6%$, men - ${\Delta}_R=-170.9%$ and women - ${\Delta}_R=-141.0%$) was overwhelming. Conclusions: This investigation was the first epidemiological study of dynamics of laryngeal cancer by component analysis in population of Kazakhstan. Implementation of the results of the study is recommended in management of anti-cancer activities for laryngeal cancer.

• 대한화학회지
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• 제12권2호
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• pp.61-64
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• 1968

Compressibility and expansibility of activation, ${\Delta}K^{\neq}\;and\;{\Delta}E^{\neq},$ are defined with the use of general principles that an activation parameter is the difference in partial molar quantities of the parameter for the transition and initial state. Two related parameters, (${\partial}{\Delta}H^{\neq}/{\partial}P)_{\gamma}\;and\;{\Delta}W^{\neq}(=P{\Delta}V^{\neq}),$ are also derived. Simpler interpretation of the existing kinetic data are possible with these activation parameters, while other derivations lead to complicated expressions of no practical significance.

• 대한화학회지
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• 제7권3호
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• pp.211-215
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• 1963

Inter-relationship between the Hammett equation and the linear enthalpy-entropy effect has been discussed by deriving a new set of equations; ${\Delta}{\Delata}H^{\neq}=a{\sigma}+b{\Delta}{\Delta}S^{\neq}$ and ${\Delta}{\Delta}F^{\neq}=a{sigma}+(b-T){\Delta}{\Delta}S^{\neq}$ where a = -1.36p. Theoretical analysis show that the Hammett, Leffler and Brown equations are special limited forms of these general equations. A necessary and sufficient test of substituent effect can thus be provided by the plot of $({\Delta}{\Delta}H^{\neq}-a{\sigma)$ versus ${\Delta}{\Delta}S^{\neq}$.

• 한국산업보건학회지
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• 제6권1호
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• pp.77-87
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• 1996

다량의 연을 사용하는 제조업 중에서 7개의 축전지 제조업, 3개의 폐전지 제련공장, 그리고 2개의 연분 및 광명단을 제조 또는 사용하는 사업장 총 11개 대상 사업장에서 정기 보건관리시 혈중 Zinc Protoporphyrin 농도를 고려하여 생산직 남자 근로자 234명을 선정, 혈액에서 혈중연, 혈중 ZPP, 혈색소 등을 측정하고 소변에서 ${\delta}$-ALA 배설량을 비색법과 HPLC법으로 분석하여 그 차이점을 확인하고 연노출 지표들과의 관련성을 조사하여 연중독 판정기준의 새로운 기준을 마련하기 위하여 본 연구를 시도한 바 결과는 다음과 같다. 1. 비색법과 HPLC법에 의한 요중 ${\delta}$-ALA 배설량은 높은 상관성이 있으나 비색법이 HPLC법 보다 2 mg/L 정도 높게 측정되었다(r = 0.989, 회귀식 ; HALA = - 0.8194 + 0.8110 ${\times}$ CALA) 2. 요중 ${\delta}$-ALA 배설량은 두 방법 모두 혈중연 및 혈중 ZPP 농도와의 상관계수가 각각 0.46, 0.37 이상이었으며, ${\delta}$-ALA 배설량을 대수변환하였을 때는 상관계수가 0.63, 0.57로 높아졌으며 통계적으로도 유의하였다. 3. 혈중 ZPP를 독립변수로, 비색법과 HPLC법에 의한 요중 ${\delta}$-ALA 배설량을 종속변수로 한 단순회귀방정식은 다음과 같다. CALA = 2.0421 + 0.0341 ${\times}$ ZPP $R^2=0.1385$ p = 0.0001 HALA = 0.8006 + 0.0280 ZPP $R^2=0.1389$ p = 0.001 4. 혈중연을 독립변수로, 비색법과 HPLC법에 의한 요중 ${\delta}$-ALA 배설량을 종속변수로 한 단순 회귀 방정식은 다음과 같다. CALA = - 0.4134 + 0.1545 ${\times}$ PbB $R^2=0.2085$ p = 0.0001 HALA = - 1.2893 + 0.1287 ${\times}$ PbB $R^2=0.2154$ p = 0.0001 5. 비색법과 HPLC법에 의한 요중 ${\delta}$-ALA 배설량을 대수변환하였을 때 혈중연 및 혈중 ZPP를 독립변수로 하는 회귀식은 다음과 같다. logHALA = 0.3078 + 0.0060 ${\times}$ ZPP $R^2=0.3329$ p = 0.0001 logCALA = 1.0189 + 0.0044 ${\times}$ ZPP $R^2=0.3290$ p = 0.0001 logHALA = - 0.0221 + 0.0246 ${\times}$ PbB $R^2=0.4046$ p = 0.0001 logCALA = 0.7662 + 0.0184 ${\times}$ PbB $R^2=0.4108$ p = 0.0001 6. 요중 ${\delta}$-ALA 배설량에 대한 연중독 주의한계의 cut-off point를 5 mg/L로 하였을 경우 혈중연과 혈중 ZPP의 주의한계에 대한 비색법의 누적 빈도가 HPLC법 보다 높았으며, 따라서 HPLC법의 cut-off point를 3 mg/L로 하였을 때 비색법과 좋은 일치도를 보였고 연노출지표들과 량-반응 관계를 나타내었다. 이상의 결과로 연중독 판정기준의 주의한계와 선별한계의 개정이 필요하나 남자 근로자들만의 연구이므로 여자 근로자에 관한 연구가 추가로 필요하다고 생각된다.

• 한국지반공학회논문집
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• 제22권8호
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• pp.77-88
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• 2006

본 연구에서는 말뚝-지반의 상호작용을 고려한 Pile-Bent 구조물의 수평하중 해석기법을 제안하였다. 특히, 수평하중이 작용하는 Pile-Bent 구조물의 특성을 고려한 재료의 항복거동과 기하학적 비선형 거동인 $P-{\Delta}$ 효과를 해석기법에 도입하였다. 개발한 해석기법상의 현장타설 말뚝은 보-기둥 모델을 적용하였으며 지반은 비선형 하중전이 함수를 이용하였다. 본 연구결과, 강하부 일체형인 Pile-Bent 구조물의 경우 해석방법(재료의 탄성 또는 비탄성)에 따라 수평변위의 차가 크게 발생하였다. 재료의 항복거동만 고려할 경우 최대 휨 모멘트($M_{max}$)는 지표 아래의 약 3.5D(D는 말뚝직경) 깊이에서 발생되었으며, 재료의 항복거동과 $P-{\Delta}$ 효과를 모두 고려할 경우 $M_{max}$의 지점이 다소 상승하여 지표 아래 약 1.5D 깊이에서 발생하였다. 세장비에 따른 재료의 항복 및 $P-{\Delta}$ 효과는 단주일 경우에는 재료의 항복거동이, 장주일 경우에는 $P-{\Delta}$ 효과에 의한 기하학적 비선형 거동이 수평변위의 주요 영향인자임을 확인하였다.

• 대한수학회보
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• 제52권2호
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• pp.581-591
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• 2015

Let $\mathcal{A}$ be a factor von Neumann algebra with dimension greater than 1. We prove that if a linear map ${\delta}:\mathcal{A}{\rightarrow}\mathcal{A}$ satisfies $${\delta}([[a,b],c])=[[{\delta}(a),b],c]+[[a,{\delta}(b),c]+[[a,b],{\delta}(c)]$$ for any $a,b,c{\in}\mathcal{A}$ with ab = 0 (resp. ab = P, where P is a fixed nontrivial projection of $\mathcal{A}$), then there exist an operator $T{\in}\mathcal{A}$ and a linear map $f:\mathcal{A}{\rightarrow}\mathbb{C}I$ vanishing at every second commutator [[a, b], c] with ab = 0 (resp. ab = P) such that ${\delta}(a)=aT-Ta+f(a)$ for any $a{\in}\mathcal{A}$.

• 대한수학회지
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• 제53권4호
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• pp.929-967
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• 2016

Let p(t, x) be the fundamental solution to the problem $${\partial}^{\alpha}_tu=-(-{\Delta})^{\beta}u,\;{\alpha}{\in}(0,2),\;{\beta}{\in}(0,{\infty})$$. If ${\alpha},{\beta}{\in}(0,1)$, then the kernel p(t, x) becomes the transition density of a Levy process delayed by an inverse subordinator. In this paper we provide the asymptotic behaviors and sharp upper bounds of p(t, x) and its space and time fractional derivatives $$D^n_x(-{\Delta}_x)^{\gamma}D^{\sigma}_tI^{\delta}_tp(t,x),\;{\forall}n{\in}{\mathbb{Z}}_+,\;{\gamma}{\in}[0,{\beta}],\;{\sigma},{\delta}{\in}[0,{\infty})$$, where $D^n_x$ x is a partial derivative of order n with respect to x, $(-{\Delta}_x)^{\gamma}$ is a fractional Laplace operator and $D^{\sigma}_t$ and $I^{\delta}_t$ are Riemann-Liouville fractional derivative and integral respectively.

• 대한한방내과학회지
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• 제19권1호
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• pp.157-167
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• 1998

Background and Purpose : Cerebrovascular reactivity(CVR) can be estimated by measuring the change of cerebral blood flow that occurs during vasostimulation. To estimate the cerebrovascular reactivity, we investigated the change of flow velocity of the middle cerebral artery(MCA) during hyperventilation and hypoventilation with the transcranial doppler. So we studied whether the CVR measured by this method could show a significant difference between the normal and the cerebral infarction subjects and whether the CVR may decrease with age in normal subjects. Methods : Using transcranial doppler, we measured the mean velocity(Vm), the pulsatility index(P.I.) at the resting state, the end of breath-holding and the end of hyperventilation in 36 normal and 10 cerebral infarction subjects, so we calculated the percentile change of mean velocity(%${\Delta}$Vm) and P.I.(%${\Delta}$P.I.) after the vasostimulation. We estimated the change of Vm, P.I., %${\Delta}$Vm and %${\Delta}$P.I. by the age group and compared those parameters between the age-matched normal control and cerebral infarction subjects. Results : The Vm in MCA significantly decreased with age(p<0.05), but there was no significant difference in Vm and P.I. between normal and cerebral infarction subjects. The %${\Delta}$Vm and %${\Delta}$P.I. in response to hyperventilation significantly decreased with age in MCA and there was significant difference in $%{\Delta}Vm$ of MCA after breath-holding between the normal and cerebral infarction subjects. Conclusion : The breath-holding and hyperventilation tests could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied in the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.541-544
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• 1998

A SiGe p-channel MESFET using $\delta-doped$ layers is designed and the considerable enhancement of the current driving capability of the device is observed from the result of simulation. The channel consists of double $\delta-doped$ layers separated by a low-doped spacer which consists of Si and SiGe. A quantum well is formed in the valence band of the Si/SiGe heterojunction and much more holes are accumulated in the SiGe spacer than those in the Si spacer. The saturation current is enhanced by the contribution of the holes inthe spacer. Among the design parameters that affect the performance of the device, the thickness of the SiGe layer and the Ge composition are studied. The thickness of $0~300\AA$ and the Ge composition of 0~30% are investigated, and the saturation current is observed to be increased by 45% compared with a double $\delta-doped$ Si p-channel MESFET.