• East Asian mathematical journal
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• v.30 no.3
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• pp.355-360
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• 2014

Let D be a finite digraph with the vertex set V (D) and the arc set A(D). A function f : $V(D){\rightarrow}\{-1,\;1\}$ defined on the vertices of a digraph D is called a bad function if $f(N^-(v)){\leq}1$ for every v in D. The weight of a bad function is $f(V(D))=\sum\limits_{v{\in}V(D)}f(v)$. The maximum weight of a bad function of D is the the negative decision number ${\beta}_D(D)$ of D. Wang [4] studied several sharp upper bounds of this number for an undirected graph. In this paper, we study sharp upper bounds of the negative decision number ${\beta}_D(D)$ of for a digraph D.

• Kyungpook Mathematical Journal
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• v.57 no.4
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• pp.667-676
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• 2017

We study the positive $C^1$ function z = f(x, y) defined on the plane ${\mathbb{R}}^2$. For a rectangular domain $[a,b]{\times}[c,d]{\subset}{\mathbb{R}}^2$, we consider the volume V and the surface area S of the graph of z = f(x, y) over the domain. We also denote by (${\bar{x}}_V,\;{\bar{y}}_V,\;{\bar{z}}_V$) and (${\bar{x}}_S,\;{\bar{y}}_S,\;{\bar{z}}_S$) the geometric centroid of the volume under the graph of z = f(x, y) and the centroid of the graph itself defined on the rectangular domain, respectively. In this paper, first we show that among nonconstant $C^2$ functions with isolated singularities, S = kV, $k{\in}{\mathbb{R}}$ characterizes the family of catenary rotation surfaces f(x, y) = k cosh(r/k), $r={\mid}(x,y){\mid}$. Next, we show that one of $({\bar{x}}_S,\;{\bar{y}}_S)=({\bar{x}}_V,\;{\bar{y}}_V)$, $({\bar{x}}_S,\;{\bar{z}}_S)=({\bar{x}}_V,\;2{\bar{z}}_V)$ and $({\bar{y}}_S,\;{\bar{z}}_S)=({\bar{y}}_V,\;2{\bar{z}}_V)$ characterizes the family of catenary rotation surfaces among nonconstant $C^2$ functions with isolated singularities.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7889-7892
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• 2015

Background: Primary idiopathic myelofibrosis (PMF) is a clonal Ph-chromosome negative myeloproliferative neoplasm characterized by dysregulated kinase signaling and release of abnormal cytokines. In the recent past, following JAK2 V617F mutation invention, important revolution has been made in the molecular diagnostic biology of this disease. The rational of this study was to determine the mutational status of JAK2 V617F in Pakistan patients with PMF. Materials and Methods: In this cross sectional study, 20 patients with PMF were enrolled from January 2011 to December 2014. Diagnosis was based on WHO criteria for PMF. All patients were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by allele specific PCR. Results: The mean age was $57.9{\pm}16.5years$. The male to female ratio was 3:1. The frequency of JAK2 V617F positivity in our PMF patients was found to be 55%. Positive correlations of JAK2 V617F mutation were established with high TLC count, raised LDH and marked splenomegaly (P<0.05). No correlation of JAK2 V617F could be established with age and gender (P>0.05). Conclusions: The JAK2 V617F mutation frequency in our PMF patients was similar to those reported previously. In our hands JAK2 V617F mutated patients expressed an aggressive disease phenotype. Screening for the mutation in all suspected PMF cases could be beneficial in differentiating patients with reactive and clonal marrow fibrosis.

• Communications of the Korean Mathematical Society
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• v.9 no.4
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• pp.837-846
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• 1994

Let A denote a unital normed algebra over a field K = R or C and let e be the identity of A. Given $a \in A$ and $x \in A$ with $\Vert x \Vert = 1$, let $$ V(A, a, x) = {f(ax) : f \in A', f(x) = 1 = \Vert f \Vert}. $$ Then the (Bonsall and Duncan) numerical range of an element $a \in A$ is defined by $$ V(a) = \cup{V(A, a, x) : x \in A, \Vert x \Vert = 1}, $$ where A' denotes the dual of A. In [2], $V(a) = {f(a) : f \in A', f(e) = 1 = \Vert f \Vert}$.

• Journal of IKEEE
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• v.28 no.1
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• pp.110-115
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• 2024

This paper analyzed the V_th (Threshold Voltage) variations in 3D NAND Flash memory with tapered O/N/O (Oxide/Nitride/Oxide) structure and O/N/F (Oxide/Nitride/Ferroelectric) structure, where the blocking oxide is replaced by ferroelectric material. With a tapering angle of 0°, the O/N/F structure exhibits lower resistance compared to the O/N/O structure, resulting in reduced V_th variations in both the upper and lower regions of the WL (Word Line). Tapered 3D NAND Flash memory shows a decrease in channel area and an increase in channel resistance as it moves from the upper to the lower WL. Consequently, as the tapering angle increases, the V_th decreases in the upper WL and increases in the lower WL. The tapered O/N/F structure, influenced by V_fe proportional to the channel radius, leads to a greater reduction in V_th in the upper WL compared to the O/N/O structure. Additionally, the lower WL in the O/N/F structure experiences a greater increase in V_th compared to the O/N/O structure, resulting in larger V_th variations with increasing tapering angles.

• Journal of computational fluids engineering
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• v.8 no.2
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• pp.1-7
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• 2003

The V2F turbulence model, which has shown very good performance in several test cases at low speeds, has been applied to supersonic ramp flow with 20. corner angle at the free stream Mach number of 2.79. The flow is known to manifest strong shock wave/turbulent boundary layer interactions. As a comparative study, low-Reynolds k-ε models are also considered. While the V2F model predicts wall-pressure distribution well, it relatively predicts larger separation bubble and higher skin-friction after the reattachment than the experimental data. Although the ellpticity of f equation is the characteristics of incompressible flows, the converged solutions are acquired in the compressible flow with shock waves. The effect of the realizability constraints used in the model is also examined. In contrast to the result of impinging jet flows, the realizability bounds proposed by Durbin deterioate the overall solutions of the supersonic ramp flow.

• Bulletin of the Korean Mathematical Society
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• v.55 no.3
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• pp.921-935
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• 2018

In this study we determine the structure of m-adic residue codes over the non-chain ring $F_q[v]/(v^2-v)$ and present some promising examples of such codes that have optimal parameters with respect to Griesmer Bound. Further, we show that the generators of m-adic residue codes serve as a natural and suitable application for generating reversible DNA codes via a special automorphism and sets over $F_{4^{2k}}[v]/(v^2-v)$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.133-140
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• 2002

To evaluate the anti metastatic effect of Antivascular-first(AntiV-F), we investigated cytotoxic effect on B16-F10 and HMCB. gene expression of MMP-9 and nm23-H1, and survival. After treating with AntiV-F, AntlV-F promoted cytotoxic effect on B16-F10 and HMCB as its density, compared with Control. AntiV-F inhibited gene expression of MMP-9 in the L+14 and HMCB cell line compared with Control. On the other hand AntiV-F increases gene expression of nm23-H1 and survival about 30% compared with Control. These results suggest that AntiV-F has effects on anti-metastasis can be used for treatment of cancer patients and preventing recurrence.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.48-58
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• 1998

For the purpose of designing novel capacitance pressure sensor, several effects on sensitivity such as parasitic capacitance effects, temperature/thermal drift and leakage current have to be eleiminated. This paper proposed the experimental studies on frequency compensation method by electronic circuit technique, C-V converting method with switched capacitor and C-F converting method with schmitt trigger circuit. The third interface circuit by frequency compensation method is composed to eliminate the drift and leakage component by comparision sensing frequency with reference frequency. The signal transmission is realized by digital signal to minimize the influence of noise and high resolution is obtained by means of increasing the number of digital bits. In the fabricated high performance C-V interface, the offset voltage was not appeared, and in case of voltage source, 4.0V, feed back capacitance, 10㎊, the pressure, 0~10 ㎪, the sensitivity of C-V converter is 28 ㎷/㎪.V, the temperature drift characteristic, 0.051 %F.S./$^{\circ}C$ and C-F converter shows -6.6 Hz/pa, 0.078 %F.S./$^{\circ}C$ respectively, relatively good ones.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.466-469
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• 2001

In this paper, closed loop V/f control of induction motor has been implemented by the estimated speed. Closed loop V/f control improve the performance of induction motor drive system at low speed compared to open loop V/f control. However, closed loop V/f control need speed sensor. By using the estimated speed, closed loop V/f control is possible without speed sensor. Rotor speed is calculated from the difference between synchronous frequency and slip angular frequency. 3-phase voltage reference is obtained from synchronous frequency. And the PWM technique using space vector PWM is applied in this scheme. In the space vector PWM, effective time of 3-phase voltage reference is used to simplify the calculation of effective voltage time. This scheme is simple to implement and one chip microprocessor was used in experimental system.