• Journal of applied mathematics & informatics
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• v.4 no.1
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• pp.147-166
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• 1997

The convergence of the power sequence of an $n{\times}n$ fuzzy matrix has been studied. Some theoretical necessary and sufficient con-ditions have been established for the power sequence to be convergent generally. Furthermore as one of our main concerns the convergence index was studied in detail especially for some special types of Boolean matrices. Also it has been established that the convergence index is bounded by $(n-1)^2+1$ from above for an arbitrary $n{\times}n$ fuzzy matrix if its power sequence converges. Our method is concentrated on the limit behavior of the power se-quence. It helped us to make our proofs be simpler and more direct that those in pure algebraic methods.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.973-981
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• 2008

In this paper we focus on a type of Unimodular polynomial pair used for digital systems and present some new properties of them which lead us to estimation of their autocorrelation coefficients and the moments of a Rudin-Shapiro polynomial product. Some new results on the Rudin-shapiro sequences will be presented in the last section. Main Facts: For positive integers M and n with $M\;<\;2^n$ - 1, consider the $2^n$ - M numbers ${\epsilon}_k$ ($M\;{\leq}\;k\;{\leq}\;2^n$ - 1) which form a collection of Rudin-Shapiro coefficients. We verify that $|{\sum}_{k=M}^{2^{n-1}}\;{{\epsilon}_k}e^{ikt}|$ is dominated by $(2+\sqrt{2})\;\sqrt {2^n-M}-{\sqrt{2}}$.

• Journal of the Korean Mathematical Society
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• v.44 no.3
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• pp.499-509
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• 2007

Let m, n be positive integers or monic polynomials in $\mathbb{F}_q[T]$ with n|m. Let $K_m\;and\;K^+_m$ be the m-th cyclotomic field and its maximal real subfield, respectively. In this paper we define two matrices $D^+_{m,n}\;and\;D^-_{m,n}$ whose determinants give us the ratios $\frac{h(\mathcal{O}_{K^+_m})}{h(\mathcal{O}_{K^+_n})}$ and $\frac{h-(\mathcal{O}_K_m)}{h-(\mathcal{O}_K_n)}$ with some factors, respectively.

• Journal of Korean Library and Information Science Society
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• v.21
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• pp.231-252
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• 1994

Library authorities are responsible for allocating its resources to best achieve library goals. This means the question of benefits and costs for library activities, as well as a n.0, pplication of economic theory to it. To consider these, this study dealt with theoretical analysis: 1) the nature of economic models, 2) economic theory to library activities, 3) and its a n.0, pplicability. However, economic model method allows us to use an analytic technique that is founded on library production and consumption. Thus, its major contribution is creation of a framework or system for maximizing the efficient library activities.

• Communications of the Korean Mathematical Society
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• v.11 no.1
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• pp.245-252
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• 1996

The relative Nielsen number N(f;X,A) was introduced in 1986. It gives us a better, and ideally sharp, lower bound for the minimum number MF[f;X,A] of fixed points in the homotopy class of the map $f;(X,A) \to (X,A)$. Similarly, we also can think about the Nielsen map $f:(X,A) \to (X,A)$. Similarly, we also can be think about the Nielsen root theory. In this paper, we introduce a relative root Nielsen number N(f;X,A,c) of $f:(X,A) \to (Y,B)$ and show some basic properties.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.59-64
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• 2007

Purpose : Suprapubic aspiration(SPA) has been considered the "gold standard" for obtaining urine in non-toilet trained infants. Ultrasound(US)-guided SPA improves the success rate of the procedure and reduces the complications. However, many physicians perceive SPA as invasive and prefer the use of urethral catheterization (Ucat). We compared the success rate, complications and accuracy of US-guided SPA and Ucat. Methods : 121 infants who visited Ewha Womans University Mokdong Hospital with suspected urinary tract infection(UTI) were investigated. For the first study, the study infants were randomly assigned to either the US-guided SPA(n=32) or Ucat(n=32) groups. The success rate and complications of both procedures were compared. For the second study, US-guided SPA and Ucat were performed simultaneously(n=57). The accuracy of urethral catheterization was subsequently analyzed. The criteria for success was defined as the collection of more than 0.5 mL of urine. UTI was diagnosed by the presence of uropathogens over 105 colony-forming units (CFU)/mL. Results : The overall success rate of the US-guided SPA was 96.9%(71.9% in first attempts, 25.0% in second attempts) which was not significantly different compared to 96.9%(90.6% in first attempts, 6.3% in second attempts) in the Ucat(P>0.05) group. The aspirated urine volume was $7.4{\pm}3.7mL$ in the US-guided SPA group, which was not significantly different to $4.5{\pm}2.6mL$ in the Ucat(P>0.05) group. The accuracy of Ucat in comparison to the US guided SPA was low with sensitivity 59.5%, specificity 86.6%, false-positive rate 13.3% and false-negative rate 40.5%. Conclusion : US-guided SPA should be encouraged as the best method to collect the urine in non-toilet trained infants with UTI.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1077-1086
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• 2021

Objective: To investigate the diagnostic performance of quantitative ultrasound (US) parameters for the assessment of hepatic steatosis in patients with nonalcoholic fatty liver disease (NAFLD) using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. Materials and Methods: In this single-center prospective study, 120 patients with clinically suspected NAFLD were enrolled between March 2019 and January 2020. The participants underwent US examination for radiofrequency (RF) data acquisition and chemical shift-encoded liver MRI for PDFF measurement. Using the RF data analysis, the attenuation coefficient (AC) based on tissue attenuation imaging (TAI) (AC-TAI) and scatter-distribution coefficient (SC) based on tissue scatter-distribution imaging (TSI) (SC-TSI) were measured. The correlations between the quantitative US parameters (AC and SC) and MRI-PDFF were evaluated using Pearson correlation coefficients. The diagnostic performance of AC-TAI and SC-TSI for detecting hepatic fat contents of ≥ 5% (MRI-PDFF ≥ 5%) and ≥ 10% (MRI-PDFF ≥ 10%) were assessed using receiver operating characteristic (ROC) analysis. The significant clinical or imaging factors associated with AC and SC were analyzed using linear regression analysis. Results: The participants were classified based on MRI-PDFF: < 5% (n = 38), 5-10% (n = 23), and ≥ 10% (n = 59). AC-TAI and SC-TSI were significantly correlated with MRI-PDFF (r = 0.659 and 0.727, p < 0.001 for both). For detecting hepatic fat contents of ≥ 5% and ≥ 10%, the areas under the ROC curves of AC-TAI were 0.861 (95% confidence interval [CI]: 0.786-0.918) and 0.835 (95% CI: 0.757-0.897), and those of SC-TSI were 0.964 (95% CI: 0.913-0.989) and 0.935 (95% CI: 0.875-0.972), respectively. Multivariable linear regression analysis showed that MRI-PDFF was an independent determinant of AC-TAI and SC-TSI. Conclusion: AC-TAI and SC-TSI derived from quantitative US RF data analysis yielded a good correlation with MRI-PDFF and provided good performance for detecting hepatic steatosis and assessing its severity in NAFLD.

• Korean Journal of Mathematics
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• v.14 no.1
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• pp.125-136
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• 2006

Using the Bumping algorithm for the shifted rim hook tableaux described in [5], we construct Schensted insertion and deletion algorithms for shifted rim hook tableaux. This may give us the combinatorial proof for the orthogonality of the second kind of the spin characters of $S_n$.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.3
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• pp.421-426
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• 1994

Twelve cross bred cows ($300{\pm}20kg$) were fed a basal ration consisting of 1 kg concentrate and untreated or urea treated rice with or without urea-molasses-wheat bran lick block supplementation. The lick blocks were prepared locally using cement as a binding agent. The experiment lasted for 48 days consisting of a preliminary period of 14 days and a measurement period of 34 days. Daily dry ma tter intake (DMI) of straw and lick block, and daily milk yield were recorded during the measurement period. Intake of lick block when fed with untreated straw (US) was significantly higher (p < 0.01) than with urea treated (TS) straw (397 vs 307g $100kg^{-1}$), but lick block supplementation did not significantly affect the in take of US (1.80 vs 1.83kg $100kg^{-1}day^{-1}$) or TS (2.27 vs 2.17kg $100kg^{-1}day^{-1}$). Both urea treatment and lick block supplementation significantly increased (p < 0.01) the milk yield of cows, and the increase due to urea treatment was higher than that due to lick block supplementation. Benefit/cost ratio obtained for feeding US or TS with 1 kg dairy concentrate was similar (5.4), but the marginal return favours TS (5.4:1.0). The benefit/cost ratio for US and TS supplemented with lick block was 3.4 and 3.7. respectively, but the marginal return with US was higher than with TS (1.6:1.0 and 0.9:1.0, respectively).

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.23.1-23.9
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• 2018

Objectives: This study evaluated the effect of ultrasonic agitation of mineral trioxide aggregate (MTA), calcium silicate-based cement (CSC), and Sealer 26 (S26) on adaptation at the cement/dentin interface and push-out bond strength. Materials and Methods: Sixty maxillary canines were divided into 6 groups (n = 10): MTA, S26, and CSC, with or without ultrasonic activation (US). After obturation, the apical portions of the teeth were sectioned, and retrograde cavities were prepared and filled with cement by hand condensation. In the US groups, the cement was activated for 60 seconds: 30 seconds in the mesio-distal direction and 30 seconds in the buccal-lingual direction, using a mini Irrisonic insert coupled with the ultrasound transducer. After the materials set, 1.5-mm thick sections were obtained from the apexes. The presence of gaps and the bond between cement and dentin were analyzed using low-vacuum scanning electron microscopy. Push-out bond strength was measured using a universal testing machine. Results: Ultrasonic agitation increased the interfacial adaptation of the cements. The S26 US group showed a higher adaptation value than MTA (p < 0.05). US improved the push-out bond strength for all the cements (p < 0.05). Conclusions: The US of retrograde filling cements enhanced the bond to the dentin wall of the root-end filling materials tested.