• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.20-26
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• 2000

In this work, the degradation of g$_{m}$ , f$_{T}$ and f$_{max}$ of RF-CMOS devices have been characterized at elevated temperature. Since MOS transistors in RF applications are usually in saturation region, a simple empirical model for temperature dependence of g$_{m}$ at any measurement bias has been suggested. Because f$_{T}$ and f$_{max}$ of CMOS devices are proportional to g$_{m}$, the temperature dependence of f$_{T}$ and f$_{max}$ could be obtained from the temperature dependence of g$_{m}$. It was found that the degradation of f$_{T}$ and f$_{max}$ at elevated temperature was due to the degradation of g$_{m}$. From the correlation between DC and RF performances of CMOS devices, we can predict the enhanced f$_{T}$ and f$_{max}$ performances at low temperature.

• Journal of the Korean Statistical Society
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• v.21 no.2
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• pp.153-166
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• 1992

Consider an unknown regression function f of the response Y on a d-dimensional measurement variable X. It is assumed that f belongs to a tensor Sobolev space. Let T denote a differential operator. Let $\hat{T}_n$ denote an estimator of T(f) based on a random sample of size n from the distribution of (X, Y), and let $\Vert \hat{T}_n - T(f) \Vert_2$ be the usual $L_2$ norm of the restriction of $\hat{T}_n - T(f)$ to a subset of $R^d$. Under appropriate regularity conditions, the optimal rate of convergence for $\Vert \hat{T}_n - T(f) \Vert_2$ is discussed.

• Communications of the Korean Mathematical Society
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• v.13 no.1
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• pp.77-84
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• 1998

In this note we show that if $T_{\varphi}$ is a Toeplitz operator with quasicontinuous symbol $\varphi$, if $\omega$ is an open set containing the spectrum $\sigma(T_\varphi)$, and if $H(\omega)$ denotes the set of analytic fuctions defined on $\omege$, then the following statements are equivalent: (a) $T_\varphi$ is semi-quasitriangular. (b) Browder's theorem holds for $f(T_\varphi)$ for every $f \in H(\omega)$. (c) Weyl's theorem holds for $f(T_\varphi)$ for every $f \in H(\omega)$. (d) $\sigma(T_{f \circ \varphi}) = f(\sigma(T_varphi))$ for every $f \in H(\omega)$.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.57-62
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• 1977

Der Zuwachs des Durchmessers des Einzelbaumes kann durch die Differenzialgleichung dx/dt=k(M-x)+f(t) beschrieben werder, wobei f(t) die von den zuf$\ddot{a}$lligen $\ddot{A}$nderungen der Umwelt bedingte Fluktuation des Wachstums bedeutet. Nach dieser Gleichung kann das Wachstum des Durchmessers des Einzelbaumes in zwei Teile zerlegt werden: der erste systematische Teil k(M-x) repr$\ddot{a}$sentiert den Trend des Wachstums und der zweite Teil die Fluktuation f(t), die f$\ddot{u}$r die Wald bewirtschaftung von Praktischer Bedeutung ist. Die Studie zeigt die mathematische Ableitung zur Bestimmung von f(t).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.226-232
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• 1982

The measurements of the jerking force and the tail beat by hooked carp were carried out using a strain gauge at a fish pond from July to August 1981. The maximum jerking force was sustained for a while in the initial state after a carp was hooked, but the jerking force was gradually decreased as a function of the time elapsed until the fish was utterly exhausted, and it converged to the body weight at last. The results are as follows : 1. The maximum jerking force $F_m(g)$ can be expressed with empirical formula : $$F_m=3.23W+105$$ where W (g) is the body weight. 2. Dynamic change of the maximum jerking force $F_n(g)$ by one tail beat with time $t_{n}(-10T/2{\leq}\;t_n{\leq}10T/2)$ can he induced with the equation as follows : $$F_n=(0.27W-6.52)(|t_n|+C)^{-2.10}$$ where the period T (sec) is given by the following equation with the body weight : T=0.000385W+0.193 3. The jerking force at each of the peak points $F_p$ (g) varies with the time elapsed t (sec) as following equation : $$F_{p}=(2.23W+105)e^{-{\beta}t}+W$$. The value of durability index $\beta$ was nearly zero in the initial state and about 1.7 in the exhausted state at last. 4. It was clearly shown that the change of jerking force by hooked carp was closely related to the tail beat from a paired difference T-test.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.217-228
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• 2019

This study was designed to investigate the effect of exercise prescription service on user satisfaction and reuse intention of fitness center users in C region, Gangwon-do. The subjects of this study were 250 fitness center users aged 20 and over. Survey was conducted to examine users satisfaction and reuse intention. The final analysis data is 227 copies and the results are as follows. First, there was a significant difference in sex at the facility of satisfaction of use(t=2.308, p=.022). The marriage showed a significant difference in the price among user satisfaction(t=2.490, p=.014) and reuse intention(t=-1.968, p=.05). Age showed significant differences in the duration of participation(F=7.117, p=.000), frequency (F=6.171, p=.000), and intensity(F=2.791, p=.027). User satisfaction showed significant differences according to price(F=6.171, p=.000), leader(F=3.083, p=.017) and reuse intention(F=2.699, p=.032). There was a significant difference in education groups in terms of duration of participation(F=3.656, p=.007) and frequency(F=3.164, p=.015). leader(F=5.170, p=.001) and price(F=2.899, p=.023) were different in user satisfaction. Jobs showed a significant difference in the duration of participation(F=4.685, p=.000), intensity(F=2.373, p=.023) and reuse intention(F=4.840, p=.000). Monthly income showed a significant difference in user satisfaction(F=4.651, p=.001) and facility(F=2.606, p=.037). Second, there was a significant difference in the duration of participation according to presence or absence of exercise prescription service(t=-4.410, p=.000). There was also significant differences in the user satisfaction(t=-7.951, p=.000), leader(t=5.304, p=.000), facility(t=2.033, p=.043) and reuse intention(t=4.640, p=.000) in terms of the presence of exercise prescription service. Third, in the relation between exercise prescription service and the participation level, there was a significant effect of the leader(β=.221, p=.001) and the price(β=.135, p=.045) of user satisfaction, and the reuse intention(β=.182, p=.007). Fourth, among the user satisfaction influenced by exercise prescription service, facilities(β=.178, p=.005) and leader(β=.497, p=.000) were found to affect reuse intention.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.6
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• pp.24-33
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• 2000

This paper investigates the relationship between J-integral and crack tip opening displacement, ${\delta}_t$ using Gordens results of numerical analysis. Estimation were carried out for several strength levels such as ultimate, flow, yield, ultimate-flow, flow-yield stress to determine the influence of strain hardening and the ratio of crack length to width on the $J-{\delta}_t$ relationship. It was found that for SE(B) specimens, the $J-{\delta}_t$ relationship can be applied to relate J to ${\delta}_t$ as follows $J=m_j{\times}{\sigma}_i{\times}{\delta}_t$ where $m_j=1.27773+0.8307({\alpha}/W)$, ${\sigma}_i:{\sigma}_U$, ${\sigma}_{U-F}={\frac{1}{2}} ({\sigma}_U+{\sigma}_F$), ${\sigma}_F$, ${\sigma}_F}$ $Y=({\sigma}_F+{\sigma}_Y)$, ${\sigma}_Y$

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.293-302
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• 2002

The classical concept for iron uptake into mammalian cells has been the endocytosis of transferrin( $T_{f}$ )-bound F $e^{3+}$ via the $T_{f}$ - $T_{f}$ receptor cycle. In this case, we could not explain the uptake of F $e^{2＋}$ ion and the export of iron from endosome. Studies on iron transport revealed that other transport system exists in epithelial cells of the intestine. One of non- $T_{f}$ -receptor-mediated transport systems is Nramp2/DMT1/DCT1 which transports M $n^{＋＋}$, $Mg^{＋＋}$, Z $n^{＋＋}$, $Co^{＋＋}$, N $i^{＋＋}$ or C $u^{＋＋}$ ion as well as F $e^{+2}$ ion. DMT1 was cloned from intestines of iron-deficient rats and shown to be a hydrogen ion-coupled iron transporter and a protein regulated by absorbed dietary iron. DMT1 is founded in other cells such as cortical and hippocampal glial cells as well as endothelial cells in duodenum. Two F $e^{3+}$ ion bound to transferrin( $T_{f}$ ) are taken up via the $T_{f}$ - $T_{f}$ receptor cycle in the intestinal epithelial cell. F $e^{3+}$ in endosome was converted to F $e^{2＋}$ ion, and then exported to cytosol via DMT1. F $e^{2＋}$ ion is taken up into cytosol via DMT1. Several other transporters such as FET, FRE, CCC2, AFT1, SMF, FTR, ZER, ZIP, ZnT and CTR have been reported recently and dysfunction of the transporters are related with diseases containing Wilson's disease, Menkes disease and hemochromatosis. Evidences from several studies strongly suggest that DMT1 is the major transporter of iron in the intestine and functions critically in transport of other metal ions.

• Journal of applied mathematics & informatics
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• v.41 no.2
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• pp.273-286
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• 2023

In this paper we show that if T ∈ L(X) and S ∈ L(X) is a Riesz operator commuting with T and X_S(F) ∈ Lat(S), where F = {0} or F ⊆ ℂ ⧵ {0} is closed then T|X_S(F) and T|X_T(F) + S|X_S(F) share the local spectral properties such as SVEP, Dunford's property (C), Bishop's property (𝛽), decomopsition property (𝛿) and decomposability. As a corollary, if T ∈ L(X) and Q ∈ L(X) is a quasinilpotent operator commuting with T then T is Riesz if and only if T + Q is Riesz. We also study some spectral properties of Riesz operators acting on Banach spaces. We show that if T, S ∈ L(X) such that TS = ST, and Y ∈ Lat(S) is a hyperinvarinat subspace of X for which 𝜎(S|Y ) = {0} then 𝜎_*(T|Y + S|Y ) = 𝜎_*(T|Y ) for 𝜎_* ∈ {𝜎, 𝜎_loc, 𝜎_sur, 𝜎_ap}. Finally, we show that if T ∈ L(X) and S ∈ L(Y ) on the Banach spaces X and Y and T is similar to S then T is Riesz if and only if S is Riesz.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.48-53
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• 1997

The objective of this paper is to present the development and application of interface software between robot and F/T sensor for force control. The interface software for among the robot controller, F/T sensor, and host PC is based on interrupt-driven method. To show the suitability of developed interface software, writing-task is performed in real time using F/T sensor that mounts on the wrist of the robot and Scara type 4-axis robot.