• Journal of Korean Society for Quality Management
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• v.25 no.3
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• pp.11-21
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• 1997

The mean residual life(MRL) function gives the expected remaining life of a item at age t. In particular F is said to be an increasing intially then decreasing MRL(IDMRL) distribution if there exists a turing point $t^*\ge0$ such that m(s)$\le$ m(t) for 0$$\le s$\le$ t $t^*$, m(s)$\ge$ m(t) for $t^*\le$ s$\le$ t. If the preceding inequality is reversed, F is said to be a decreasing initially then increasing MRL(DIMRL) distribution. Hawkins, et al.(1992) proposed test of H0 : F is exponential versus$H_1$: F is IDMRL, and $H_0$ versus $H_1$' : F is DIMRL when turning point is unknown. Their test is based on a complete random sample $X_1$, …, $X_n$ from F. In this paper, we generalized Hawkins-Kochar-Loader test to random censored data.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.370-371
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• 1989

• Journal of the Korean Society of Systems Engineering
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• v.5 no.1
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• pp.7-20
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• 2009

This paper describes a case study on the R&D programs of fighter and attacker aircraft such as F-22A, F/A-18E/F, and T/A-50. F-22A and F/A-18E/F were developed in same age. The performance of each program was, however extremely different. F-22A program results in a lot of cost overrun and schedule delay. On the other hand F/A-18E/F program met the cost, schedule, and performance goals. In the T/A-50 program with a super-sonic advanced trainer, T-50 was also developed successfully on planned cost and time by Korea Air-force and KAI. This paper derives key elements for the success of the military aircraft R&D program through lessons learned from th e case study. Each program is analyzed in terms of its background, planning and management.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.389-390
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• 2008

The dependence of $f_T$ and $f_{max}$ on the unit finger width is measured and analyzed for $0.13{\mu}m$ MOSFETs. The increase of $f_T$ at narrow width is attributed by the parasitic gate-bulk capacitance, and the decrease of $f_T$ at wide width is generated by the reduction of increasing rate of $g_{mo}$. The increase of $f_{max}$ at narrow width is originated from the abrupt reduction of gate resistance due to the non-quasi-static effect. These analysis results will be valuable information for layout optimization to improve $f_T$ and $f_{max}$.

• Korean Journal of Mathematics
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• v.19 no.3
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• pp.279-289
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• 2011

Let E be a uniformly convex Banach space with a uniformly Gateaux differentiable norm, C be a nonempty closed convex subset of E and f : $C{\rightarrow}C$ be a fixed bounded continuous strong pseudocontraction with the coefficient ${\alpha}{\in}(0,1)$. Let $\{{\lambda}_t\}_{0<t<1}$ be a net of positive real numbers such that ${\lim}_{t{\rightarrow}0}{\lambda}_t={\infty}$ and S = {$T(s)$ : $0{\leq}s$ < ${\infty}$} be a nonexpansive semigroup on C such that $F(S){\neq}{\emptyset}$, where F(S) denotes the set of fixed points of the semigroup. Then sequence {$x_t$} defined by $x_t=tf(x_t)+(1-t)\frac{1}{{\lambda}_t}{\int_{0}}^{{\lambda}_t}T(s)x{_t}ds$ converges strongly as $t{\rightarrow}0$ to $\bar{x}{\in}F(S)$, which solves the following variational inequality ${\langle}(f-I)\bar{x},\;p-\bar{x}{\rangle}{\leq}0$ for all $p{\in}F(S)$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.352-362
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• 2016

The purpose of this study was to examine the level of stress, healthcare accreditation related job stress, adaptation, and turnover intentions, as well as to identify influencing factors of turnover intentions for operating room nurses. This study employed a descriptive correlational design. The data were collected from 163 operating room nurses using a structural questionnaire. Stress was different by age (F=5.629, p=.004), marital status (t=-2.907, p=.004), and children (t=-2.623, p=.010). Healthcare accreditation related job stress was different by age (F=11.924, p<.001), marital status (t=-4.747, p<.001), children (t=-4.434, p<.001), work experience in the OR (F=6.000, p=.003), and work reasons in the OR (t=-2.543, p=.012). Turnover intention was different by age (F=21.472, p<.001), education level (F=4.997, p<.008), religion (t=3.235, p=.001), work experience in the OR (F=13.599, p<.001), position (t=3.222, p=.002), work reasons in the OR (t=-3.001, p=.003), and a shift pattern of duties (t=-2.797, p=.006). Turnover intention was significantly correlated with stress, healthcare accreditation related job stress, and adaptation. Factors affecting turnover intention were healthcare accreditation related job stress, adaptation, and age. These factors accounted for 36.2% of turnover intention. These results suggest that relief of stress and healthcare accreditation related job stress and interventions for improving stress management.

• The Journal of Internal Korean Medicine
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• v.14 no.1
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• pp.129-138
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• 1993

This report on the $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine comes to conclude, through the study of the Oriental- Western medical references, as follow; 1. First, $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine had some concurrencies that both the two symptoms have appeared severe and recurrent headache and more often to the female. 2 Many of them e.g. Sensory disturbance, Vertigo, Nausea, Vomiting, Tinnitus etc. in the prodrome and main symptom of $T{\acute{o}}u\;f{\bar{e}}ng$ and Migraine were identical, especially the symptom of the $f{\bar{e}}ng\;t{\acute{a}}n\;t{\acute{o}}u\;t{\grave{o}}ng$ was similar to the prodrome of the Migraine. We could find out the semilarity of the symptoms through that Migraine is proximately set in unilateral, and $Pi{\bar{a}}nT{\acute{o}}u\;f{\bar{e}}ng$ is so called alias $B{\grave{a}}n\;bi{\bar{a}}n\;t{\acute{o}}u\;t{\grave{o}}ng$. 3. The pathogeny of $T{\acute{o}}u\;f{\bar{e}}ng$ include the case of ‘$f{\bar{e}}ng\;xi{\acute{e}}\;r{\grave{u}}\;n{\bar{a}}o$’, the patient feeling weak condition, $T{\acute{a}}n,\;T{\acute{a}}nshi,\;T{\acute{a}}nhu{\breve{o}},\;Y{\grave{u}}q{\grave{i}}$, etc. and, ‘$t{\acute{a}}n\;zhu{\grave{o}}\;sh{\grave{a}}ng\;y{\acute{a}}o$’, ‘$G{\bar{a}}n\;y{\acute{a}}ng\;hu{\grave{a}}\;f{\bar{e}}ng$’. There were variable that $F{\bar{e}}ng,\;Xu{\grave{e}},\;F{\bar{e}}ngr{\grave{a}},\;F{\bar{e}}ngx{\bar{u}},\;Xu{\grave{e}}x{\bar{u}},\;Hu{\check{o}}$ in the left, and $t{\acute{a}}n,\;R{\grave{e}},\;t{\acute{a}}nr{\grave{e}},\;Qir{\acute{a}}$ in the right partial pathogeny. It was referred $Sh{\grave{a}}o\;y{\acute{a}}ng\;j{\bar{i}}ng$, $Ju{\acute{e}}\;y{\bar{i}}n\;j{\bar{i}}ng$, $Y{\acute{a}}ng\;m{\acute{i}}ng\;j{\bar{i}}ng$, $T{\grave{a}}i\;y{\acute{a}}ng\;j{\bar{i}}ng$ in connection with the Meridian system. And otherwise the primary cause of Migraine is still unknown to us. Heredity is probably important, but the mode of transmission is uncertain. Recently, the important assumption is the vasomotor change caused by vasoconstrictors like that norepinephrine, epinephrine, and serotonin etc.

• Korean Journal of Radiology
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• v.24 no.6
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• pp.553-563
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• 2023

Objective: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) contribute to the localization of language areas, but their accuracy remains controversial. This study aimed to investigate the diagnostic performance of preoperative fMRI and DTI-t obtained with a simultaneous multi-slice technique using intraoperative direct cortical stimulation (DCS) or corticocortical evoked potential (CCEP) as reference standards. Materials and Methods: This prospective study included 26 patients (23-74 years; male:female, 13:13) with tumors in the vicinity of Broca's area who underwent preoperative fMRI and DTI-t. A site-by-site comparison between preoperative (fMRI and DTI-t) and intraoperative language mapping (DCS or CCEP) was performed for 226 cortical sites to calculate the sensitivity and specificity of fMRI and DTI-t for mapping Broca's areas. For sites with positive signals on fMRI or DTI-t, the true-positive rate (TPR) was calculated based on the concordance and discordance between fMRI and DTI-t. Results: Among 226 cortical sites, DCS was performed in 100 sites and CCEP was performed in 166 sites. The specificities of fMRI and DTI-t ranged from 72.4% (63/87) to 96.8% (122/126), respectively. The sensitivities of fMRI (except for verb generation) and DTI-t were 69.2% (9/13) to 92.3% (12/13) with DCS as the reference standard, and 40.0% (16/40) or lower with CCEP as the reference standard. For sites with preoperative fMRI or DTI-t positivity (n = 82), the TPR was high when fMRI and DTI-t were concordant (81.2% and 100% using DCS and CCEP, respectively, as the reference standards) and low when fMRI and DTI-t were discordant (≤ 24.2%). Conclusion: fMRI and DTI-t are sensitive and specific for mapping Broca's area compared with DCS and specific but insensitive compared with CCEP. A site with a positive signal on both fMRI and DTI-t represents a high probability of being an essential language area.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.69-74
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• 2019

Purpose $^{18}F$-FDOPA using amino acid is particularly attractive for imaging of brain tumors because of the high uptake in tumor tissue and the low uptake in normal brain tissue. But, on the other hand, $^{18}F$-FDG is highly uptake in both tumor tissue and normal brain tissue. The purpose of study is to evaluate comparison of contrasts in $^{18}F$-FDOPA Brain PET/CT and $^{18}F$-FDG Brain PET/CT and to find out optimal scan time by analysis of variation in SUV with the passage of uptake time. Materials and Methods A region of interest of approximately $350mm^2$ at the center of the tumor and cerebellum in 12 patients ($51.4{\pm}12.8yrs$) who $^{18}F$-FDG Brain PET/CT and $^{18}F$-FDOPA Brain PET/CT were examined more than once each. The $SUV_{max}$ was measured, and the $SUV_{max}$ ratio (T/C ratio) of the tumor cerebellum was calculated. In the analysis of SUV, T/C ratio was calculated for each frame after dividing into 15 frames of 2 minutes each using List mode data in 25 patients ($49.{\pm}10.3yrs$). SPSS 21 was used to compare T/C ratio of $^{18}F$-FDOPA and T/C ratio of $^{18}F$-FDG. Results The T/C ratio of $^{18}F$-FDOPA Brain PET/CT was higher than the T/C ratio of $^{18}F$-FDG Brain, and show a significant difference according to a paired t-test(t=-5.214, p=0.000). As a result of analyzing changes in $SUV_{max}$ and T/C ratio, the peak point of $SUV_{max}$ was $5.6{\pm}2.9$ and appeared in the fourth frame (6 to 8 minutes), and the peak of T/C ratio also appeared in the fourth frame (6 to 8 minutes). Taking this into consideration and comparing the existing 10 to 30 minutes image and 6 to 26 minutes image, the $SUV_{max}$ and T/C ratio increased by 0.2 and 0.1 each, compared to the 10 to 30 minutes image for 6 to 26 minutes image. Conclusion From this study, $^{18}F$-FDOPA Brain PET/CT is effective when reading the image, because the T/C ratio of $^{18}F$-FDOPA Brain PET/CT was higher than T/C ratio of $^{18}F$-FDG Brain PET/CT. In addition, in the case of $^{18}F$-FDOPA Brain PET/CT, there was no difference between the existing 10 to 30 minutes image and 6 to 26 minutes image. Through continuous research, we can find possibility of shortening examination time in $^{18}F$-FDOPA Brain PET/CT. Also, we can help physician to accurate reading using additional scan data.

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.184-193
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• 1994

This paper considers the Updating Minimum-weight Spanning Tree Problem(UMP), that is, the problem to update the Minimum-weight Spanning Tree(MST) in response to topology change of the network. This paper proposes the algorithm which reconstructs the MST after several links deleted and added. Its message complexity and its ideal-time complexity are Ο(m＋n log(t＋f)) and Ο(n＋n log(t＋f)) respectively, where n is the number of processors in the network, t(resp.f) is the number of added links (resp. the number of deleted links of the old MST), And m=t＋n if f=Ο, m=e (i.e. the number of links in the network after the topology change) otherwise. Moreover the last part of this paper touches in the algorithm which deals with deletion and addition of processors as well as links.