• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.28-33
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• 2006

La substituted perovskite $BiFeO_3$ have been prepared by a sol-gel method. Magnetic and structural properties of the powders were characterized with Mossbauer spectroscopy, XRD, SEM, and TG-DTA. The crystal structure is found to be a rhombohedrally distorted perovskite structure with the lattice constant $\alpha=3.985{\AA}\;and\;\alpha=89.5^{\circ}.\;Bi_{2/3}La_{1/3}FeO_3$ powders that were annealed at and above $600^{\circ}C$ have a single-phase perovskite structure. However, powders annealed at $900^{\circ}C$ have a typical perovskite structure with small amount of $Bi_2O_3$ phase. The Neel temperature of $Bi_{2/3}La_{1/3}FeO_3$ is found to be $680\pm3K$. The isomer shift value at room temperature is found to be 0.27 mm/s relative to the Fe metal, which is consistent with high-spin $Fe^{3+}$ charge states. Debye temperature far$Bi_{2/3}La_{1/3}FeO_3$ is found to be $305\pm5K$. The average hyperfine field $H_{hf}(T)$ of the $Bi_{2/3}La_{1/3}FeO_3$, shows a temperature dependence of $[H_{hf}(T)-H_{hf}(0)]/H_{hf}(0)=-0.42(T/T_N)^{3/2}-0.13(T/T_N)^{5/2}$ for $T/T_N<0.7$ indicative of spin-wave excitation.

• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.849-854
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• 2003

Temperature dependent thermoelectric power (TEP) of La$_{2.1}$ Sr$_{1.9}$ Mn$_3$O$_{10}$ system has been studied in the temperature range 80-373 K. In the low temperature ferromagnetic regime, TEP (S) follows an expression of formS＝S$_{0}$ ＋S$_{1.5}$ T$^{1.5}$ ＋S$_4$T$^4$ over the wide range of temperature. The broad peak below the ferromagnetic transition and complicated temperature dependence of S may be understood on the basis of electron-magnon scattering as predicted for an itinerant ferromagnet. High temperature TEP data can be well fitted with Mott's small polaron hopping model.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.129-139
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• 2012

Given digraph network $D=(N,A),n{\in}N,a=c(u,v){\in}A$ with source s and sink t, the maximum flow from s to t is determined by cut (S, T) that splits N to $s{\in}S$ and $t{\in}T$ disjoint sets with minimum cut value. The Ford-Fulkerson (F-F) algorithm with time complexity $O(NA^2)$ has been well known to this problem. The F-F algorithm finds all possible augmenting paths from s to t with residual capacity arcs and determines bottleneck arc that has a minimum residual capacity among the paths. After completion of algorithm, you should be determine the minimum cut by combination of bottleneck arcs. This paper suggests maximum adjacency merging and compute cut value method is called by MA-merging algorithm. We start the initial value to S={s}, T={t}, Then we select the maximum capacity $_{max}c(u,v)$ in the graph and merge to adjacent set S or T. Finally, we compute cut value of S or T. This algorithm runs n-1 times. We experiment Ford-Fulkerson and MA-merging algorithm for various 8 digraph. As a results, MA-merging algorithm can be finds minimum cut during the n-1 running times with time complexity O(N).

• Korean Journal of Cognitive Science
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• v.28 no.2
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• pp.91-109
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• 2017

The purpose of the research was to examine the relative effect of binocular disparity and T-junction on the determination of object's belongingness in brightness perception when regular repeating structure was present in the stimuli. Using Howe's stimuli, the variation of White illusion stimuli, Experiment 1 found that object's belongingness was mainly determined by monocular information (T-junction as well as regular repeating structure) rather than by binocular disparity when both informations on belongingness were inconsistent. Experiment 2, using the stimuli employing only regular repeating structure and binocular disparity, found that object's belongingness was not determined by any single information. These results imply that when the regular repeating structure and binocular disparity are inconsistent on object's belongingness, T-junction plays an important role in the determination of the object's belongingness and that the brightness perception is affected by it.

• Kyungpook Mathematical Journal
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• v.43 no.4
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• pp.513-518
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• 2003

In this paper, we have proved a theorem on Hausdorff summability of Fourier series which generalizes various known results. We prove that if $${\int}_{o}^{t}\;{\mid}{\phi}(u){\mid}\;du=o(t)\;as\;t{\rightarrow}0\; and\;\lim_{n{\rightarrow}{\infty}}{\int}^{\eta}_{{\pi}/n}{\frac{{\mid}{\phi}(t)-{\phi}(t+{\pi}/n){\mid}}{t}}dt=o(n)$$ where 0 < ${\eta}$ < 1, then the Fourier series is (H, ${\mu}_n$) summable to s at t = x where the sequence ${\mu}_n$ is given by ${\mu}_n={\int}^1_0x^n{\chi}(x)\;dx\;n=0,1,2\;and\;K_n(t)=\limits\sum_{{\nu}=0}^n(\array {n\\{\nu}})({\Delta}^{{n}-{\nu}}{\mu}_{\nu}){\frac{sin{\nu}t}{t}}$.

• Journal of the Korean Magnetics Society
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• v.17 no.1
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• pp.38-42
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• 2007

The crystallographic and magnetic properties of $KFeO_2$ powder prepared by ball-mill method, have been studied by x-ray diffraction(XRD), $M\"{o}ssbauer$ spectroscopy, and vibrating sample magnetometer(VSM) measurements. The crystal structure of $KFeO_2$ powder at room temperature is determined to be an orthorhombic structure of Pbca with its lattice constants $a_0=5.557{\AA},\;b_0=11.227{\AA},\;c_0=15.890{\AA}$ by Rietveld refinement. $M\"{o}ssbauer$ spectra of $KFeO_2$ were taken at various temperatures ranging from 4.2 to 818 K. The magnetic hyperfine field and isomer shift value at 4.2 K and RT were 519 kOe, 489 kOe and 0.19 mm/s, 0.05 mm/s respectively. The average hyperfine field $H_{hf}(T)$ of the $KFeO_2$ shows a temperature dependence of $[H_{hf}(T)-H_{hf}(0)]/H_{hf}(0)=-0.36(T/T_N)^{5/2}$ for $T/T_N$<0.7, indicative of spin-wave excitation.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.153-159
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• 1996

Sums of independent random variables $S_n = X_1 + X_ + cdots + X_n$ are considered, where the X$_{n}$ are chosen according to a stationary process of distributions. Given the time t .geq. O, let N (t) be the number of indices n for which O < $S_n$ $\geq$ t. In this set up we prove that N (t)/t converges almost surely and in $L^1$ as t longrightarrow $\infty$, which generalizes classical renewal theorem.m.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.613-624
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• 2004

This study was aimed at investigating the effect of fat supplementation with divalent ions such as MgO and $CaCl_2$ on 1) in vitro ruminal fermentation characteristics and insoluble fatty acid formation, and on 2) animal performance in finishing Hanwoo bulls. In in vitro trial, five different types of diets based on supplementation sources of fat and divalent ions, i.e. T=basal diet+4% tallow, T-Ca=T+0.5% $CaCl_2$, T-Mg=TA+0.5% MgO, T-MgCa = T +0.5% $CaCl_2$+0.5% MgO, T-caS =4% Ca salt tallow, were tested. Higher pH values were observed at 6 hr incubation(P<0.01) while higher amount of VFA were produced in diets 4 and 5 at 12 hr incubation(P<0.05). Nutrients(DM, OM, Crude protein and NDF) degradation tended to increase in divalent ions or Ca-salts treated tallow treatments compared with tallow treatment after 12 h. The amount of insoluble fatty acid increased by adding MgO or $CaCl_2$ to tallow or Ca soap tallow during incubation(P<0.05). In in vivo trial, thirty finishing Hanwoo(average BW 460kg) were divided into three groups based on fat sources and divalent ions, i.e. Control(EE 2.40), T-MgCa = control + tallow + $CaCl_2$ + MgO, T-CaS = control + Ca soap tallow (EE 5.30%). After feeding each diet for 80 days, average daily weight gain showed 0.89, 1.02, 1.17kg in diets 1, 2 and 3, respectively. The highest feed efficiency was observed(0.12) in diet 2 group, followed by diet 3 (0.10) and 1 groups(0.08; P < 0.05). In conclusion, the present results could be sununarized that the performance of Hanwoo bulls was improved by tallow with divalent ions without any negative effect on rumen fermentation.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.21-24
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• 2011

Oil Tight Bulkhead (O. T. Bulkhead) is one of the most important structural members of oil tankers in the views of vessel's strength and safety. Therefore O.T. bulkhead's strength should be sufficient against relevant loadings, which is normally verified by local scantling requirement and structural strength analysis defined in CSR (Common Structure Rules for Double Hull Oil Tankers). However, there is a weak-able situation when the vertical stiffeners are cut due to the penetration of cargo pipes through O. T. Bulkhead. In addition, CSR does not define how to prove the strength of this case. Therefore it is necessary to verify the structural adequacy in case that several vertical stiffeners are discontinued. This article intends to prove the strength of O. T. Bulkhead with five (5) vertical stiffeners discontinued due to pipes' penetration using the grillage analysis and the finite element analysis and to provide proper reinforcement.

• Animal Systematics, Evolution and Diversity
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• no.nspc3
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• pp.45-58
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• 1992

Tetranychoid mites found from Korea until now are 42 species belonging to 12 genera, 2 families as follows: 1 Bryobia japonica Ehara et Yamada, 2. B. praetiosa Koch, 3. B. rubrioculus(Scheuten), 4. Petrobia latens(Muller), 5. Aponychus corpuzae Rimando, 6. A firmianae(Ma et Yuan). 7. Panonychus citri(McGregor), 8. P. ulmi(Koch), 9. Eotetranychus carpini Oudemans, 10. E. hicoriae(McGregor), 11. E. populi(Koch), 12. E. rubiphilus (Reck), 13. E. sexmaculatus (Riley), 14. E. smithi Pritchard et Baker, 15. E. tiliarium (Hermann), 16. E. uchidai Ehara, 17. Schizotetranychus bambusae Reck, 18. S. celarius(Banks), 19. S. leguminosus Ehara, 20. Oligonychus aceris(Shimer), 21. O. clavatus(Ehara), 22. O. hondoensis(Ehara), 23. O. ilicis(McGregor), 24. O. karamatus(Ehara), 25. O. orthius Rimando, 26. O. peridtus Pritchard et Baker, 27. O. shinkajii Ehara, 28. O. pustulosus (Ehara), 29. O. ununguis(Jacobi), 30. O. sp. 31. Tetranychus kanzawai Kishida, 32. T. phaselus Ehara, 33. T. truncatus Ehara, 34. T. urticae Koch, 35. T. vienensis Zacher, 36. Aegyptobia nothus Pritchard et Baker, 37. Pentamerismus taxi (Haller), 38. P. oregonensis McGregor, 39. Brevipalpus californicus(Banks), 40. B. lewisi McGregor, 41. B. obovatus Donnadieu, 42. Tenuipalpus zhizhilashviliae Reck. On the above species, a taxanomic key was made and ecological data including distribution and host plant are presented in this paper.