• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1053-1055
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• 2016

Background: Polycythemia rubra vera (PV), being a primary polycythemia, is caused by neoplastic proliferation of erythroid, megakaryocytic and granulocytic lineages which result in panmyelosis. PV patients have a somatic acquired mutation in the Janus kinase (JAK2) pathway, rendering cell proliferation independent of the normal regulatory mechanisms that regulate erythropoiesis. The rational of this study was to determine the prevalence of the JAK-2 V617F mutation in Pakistani patients with PV. Materials and Methods: In this cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. Patients were diagnosed based on WHO criteria for PV. All were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR. Results: The mean age was $53.4{\pm}9.31years$ (range 36-72) and the male to female ratio was 2:1. The frequency of JAK2 V617F positivity in our PV patients was found to be 92.3%. Overall 30.7% of patients were asymptomatic and remaining 69.3% presented with symptomatic disease. The mean hemoglobin was $18.1{\pm}1.9g/dl$ with the mean hematocrit of $55.6{\pm}8.3%$. The mean total leukocyte count was $12.8{\pm}7.1{\times}10^9/l$ and the platelet count was $511{\pm}341.9{\times}10^9/l$. A positive correlation of JAK2 V617F mutation was established with high TLC count (P=0.01). No correlation of JAK2 V617F could be established with age or gender (P>0.05). Conclusions: The JAK2 V617F mutation frequency in our PV patients was similar to those reported internationally. Screening for the mutation in all suspected PV cases could be beneficial in differentiating patients with reactive and clonal erythrocytosis.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.166-168
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• 2020

MPEG 비디오 그룹은 MPEG-I 표준의 일부로 포인트 클라우드(Point Cloud) 압축을 위한 비디오 기반 포인트 클라우드 부호화(V-PCC)와 몰입형(immersive) 비디오 압축을 위한 MPEG Immersive Video(MIV) 표준을 개발하고 있다. 최근에는 포인트 클라우드 및 몰입형 비디오와 같은 체적형(volumetric) 비디오를 모두 압축할 수 있도록 V-PCC 와 MIV 를 통합한 V3C(Visual Volumetric Video-based Coding) 표준화를 진행하고 있다. 본 논문에서는 V3C 코덱을 사용한 3DoF+(3 Degree of Freedom plus) 비디오 부호화 방안을 분석한다. 또한 V3C 코덱의 2D 코덱으로 기존 HEVC 대신 VVC 를 사용할 경우의 부호화 성능 향상을 분석한다.

• 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 Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.616-624
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• 2011

The flow characteristics and heat transfer augment on the periodically arranged semi-circular ribs in a rectangular channel for turbulent flow has been investigated numerically. The aspect ratio of the rectangular channel was AR=5, the rib height to hydraulic diameter ratio were 0.07 and rib height to channel height ratio was set as e/H=0.117 for various PR(rib pitch-to-rib height rate) between 8~14, respectively. The SST k-${\omega}$ turbulence model and v2-f turbulence model were used to find out the heat transfer and the flow characteristics of near the wall which are suited to obtain realistic phenomena. The numerical analysis results show turbulent flow characteristics, heat transfer enhancement and friction factor as observed experimentally. The results predict that turbulent kinetic energy(k) is closely relative to the diffusion of recirculation flow. and v2-f turbulence model simulation results have a good agreement with experimental values.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.70-77
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• 1996

Fatigue tests were carried out at high temperature on a Cr-Mo-V steel in order to assess the fatigue life of components used in power plants. The characteristics of high temperature fatigue were divided in terms of cycle-dependent fatigue and time-dependent fatigue, each crack propagation rate was examined with respect to fatigue J-integral range, .DELTA. J$_{f}$and creep J-integral range, .DELTA. J$_{c}$. The fatigue life was evaluated by analysis of J-integral value at the crack tip with a dimensional finite element method. The results obtained from the present study are summarized as follows : The propagation characteristics of high temperature fatigue cracks are determined by .DELTA. J$_{f}$for the PP(tensile plasticity-compressive plasticity deformation) and PC(tensile plasticity - compressive creep deformation) stress waveform types, and by .DELTA. J$_{c}$for the CP(tensile creep- compressive plasticity deformation) stress waveform type. The crack propagation law of high temperature fatigue is obtained by analysis of J-integral value at the crack tip using the finite element method and applied to examine crack propagation behavior. The fatigue life is evaluated using the results of analysis by the finite element method. The predicted life and the actual life are close, within a factor of 2.f 2.f 2.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.6
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• pp.470-477
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• 2004

This study shows the design process of a MR damper for semi-active suspension systems. Damping force characteristics of the designed damper was predicted through the flow analysis and magnetic analysis. The predicted results were compared with the experimental results and the initial design specification was modified according to the results.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.231-237
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• 2011

The purpose of this study is to examine the correlation between the preferred sensation type and speech sounds, especially on $F_0$ and the speech rates. Data for the sensation types and speech sounds were collected from 36 undergraduate and graduate students (17 male, 19 female). Subjects were asked to read a given text (400 syllables), describe a drawing, and give answers to some questions. We measured speakers' $F_0$ and speech rates. The results show that type V (Visual) has the correlation with the speech rates when type D (Digital) was ruled out, and type A (Auditory) has the correlation with the speech rates when type D was included. Furthermore, the analysis of the mean values of V, A, K (Visual, Auditory, Kinethetic) indicates that type V is characterized with faster speech rates and higher $F_0$ in all parts except for interview and the same is true for that of V, A, K, D (Visual, Auditory, Kinethetic, Digital) in all parts. In conclusion, this study proved that the preferred sensation type has the correlation with $F_0$ and speech rates. Based on the results of this study, $F_0$ and speech rates can be used to analyze the sensation types for individualized education as well as consultation. In addition, this study has great significance in that it lays a foundation for the study on the correlation between a preferred sensation type and speech sounds.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.06a
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• pp.145-148
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• 1998

Fluoride({{{{ { CaF}_{2 } }}}}) films exhibited a cubic structure with similar lattice constant to that of Si and have sufficient breakdown electric field as gate dielectric material. Therefore, {{{{ { CaF}_{2 } }}}} are expected to replace conventional insulator such {{{{ { SiO}_{ 2},{Ta}_{2}{O}_{ 2} and{Al}_{2}{O}_{5}. However, {CaF}_{2}}}}} films showed hystereisis properties due to mobile charges in the film. To solve this problem we performed thermal treatment and achieves field. C-v results indicate a reduced hystereisis window of {{{{ }}}}ΔV =0.2v, LOW INTERFACE STATE {{{{{D}_{it}=2.0 TIMES {10}^{11}{cm}^{-1}{eV}^{-1}}}}} in midgap, and good WIS diode properties. We observed a preferential crystallization of(200) plane from XRD analysis. RTA treatment effects on various material properties of {{{{{CaF}_{2}}}}} are presented in this paper.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.481-496
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• 2023

Purpose: The main theme of this study is to derive a profit curve by a cubic cost function for nonlinear CVP analysis. According to the analytical approach to derive a nonlinear profit function in this study, it is possible with only the existing cost structure to calculate the profit maximization and downtime point sales unlike the classical CVP analysis. Furthermore, the profit curve by the mathematical model of this study could serve as a tool to quantify the qualitative evaluation of each stage of the industry life cycle. Methods: This study followed the mathematical approach from the cubic cost function model of microeconomics, and using real data of the Bank of Korea Results: The nonlinear profit function suggested by this study is as follows; ${\pi}(x)=-a\left(x-\frac{f}{1-v}\right)^3+(1-v)x-k$ where $a=\frac{1}{3}v\left(\frac{(1-v)}{f}\right)^2,k=f-a\left(1-\frac{f}{1-v \right)^3$ Conclusion: The process and results of this study would be able to contribute not only in practice of nonlinear CVP analysis required in the management accounting or financial management, but also in cost theory of microeconomics. Also, since the life cycle of all industries in Korea was verified to the growth or mature stage, decision makers should pay careful attention to determining life cycle stages and consider the profit curve by the average variable cost ratio over multi periods.

• Journal of computational fluids engineering
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• v.10 no.4 s.31
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• pp.1-11
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• 2005

A numerical study of the evaluation of turbulence models for thermal striping phenomenon is performed. The turbulence models chosen in the present study are the two-layer model, the shear stress transport (SST) model and the V2-f model. These three models are applied to the analysis of the triple-jet flow with the same velocity but different temperatures. The unsteady Reynolds-averaged Navier-Stokes (URANS) equation method is used together with the SIMPLEC algorithm. The results of the present study show that the temporal oscillation of temperature is predicted by the SST and V2-f models, and the accuracy of the mean velocity, the turbulent shear stress and the mean temperature is a little dependent on the turbulence model used. In addition, it is shown that both the two-layer and SST models have nearly the same capability predicting the thermal striping, and the amplitude of the temperature fluctuation is predicted best by the V2-f model.