• 한국농공학회논문집
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• 제51권2호
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• pp.51-57
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• 2009

The purpose of this study was to investigate characteristics of behavior of nutrients such as TN (Total nitrogen), TDN (Total dissolved nitrogen), TP (Total phosphorus) TDP (Total dissolved phosphorous) in runoff water from a nonpoint source dominated watershed ($6.67\;km^2$). Regular and intensive flow measurement and water sampling were taken during two years (February 2002 to January 2004) in the Ingyeong River, a tributary of the Han River. The mean concentrations of nutrients during rainy days were significantly (p < 0.05) higher than those during dry days. The mean TDN/TN ratio in rainy days (95%) is almost identical to that in dry days (96%), but mean TDP/TP ratio in rainy days (24%) significantly decreased compared with that in dry days (66%), suggesting that dominant form of TP is shifted from dissolved form to particulate form. Accordingly, the measures (.eg. filter strips, cover crops) to reduce soil erosion for fallow upland in the rainy season should be taken to control particulate phosphorous.

• 대한수학회논문집
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• 제35권2호
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• pp.591-602
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• 2020

There is a well-known class of compact, complex, non-Kählerian manifolds constructed by Bosio, called the LVMB manifolds, which properly includes the Hopf manifold, the Calabi-Eckmann manifold, and the LVM manifolds. As in the case of LVM manifolds, these LVMB manifolds can admit a regular holomorphic foliation 𝓕. Moreover, later Meersseman showed that if an LVMB manifold is actually an LVM manifold, then the regular holomorphic foliation 𝓕 is actually transverse Kähler. The aim of this paper is to deal with a converse question and to give a simple and new proof of a well-known result of Cupit-Foutou and Zaffran. That is, we show that, when the holomorphic foliation 𝓕 on an LVMB manifold N is transverse Kähler with respect to a basic and transverse Kähler form and the leaf space N/𝓕 is an orbifold, N/𝓕 is projective, and thus N is actually an LVM manifold.

• 대한수학회보
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• 제47권5호
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• pp.1025-1036
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• 2010

A new class of generalized open sets in a topological space, called e-open sets, is introduced and some properties are obtained by Ekici [6]. This class is contained in the class of $\delta$-semi-preopen (or $\delta-\beta$-open) sets and weaker than both $\delta$-semiopen sets and $\delta$-preopen sets. In order to investigate some different properties we introduce two strong form of e-open sets called e-regular sets and e-$\theta$-open sets. By means of e-$\theta$-open sets we also introduce a new class of functions called strongly $\theta$-e-continuous functions which is a generalization of $\theta$-precontinuous functions. Some characterizations concerning strongly $\theta$-e-continuous functions are obtained.

• 대한수학회지
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• 제50권6호
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• pp.1199-1211
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• 2013

We introduce a new class of graphs, called quasi $m$-Cayley graphs, having good symmetry properties, in the sense that they admit a group of automorphisms G that fixes a vertex of the graph and acts semiregularly on the other vertices. We determine when these graphs are strongly regular, and this leads us to define a new algebro-combinatorial structure, called quasi-partial difference family, or QPDF for short. We give several infinite families and sporadic examples of QPDFs. We also study several properties of QPDFs and determine, under several conditions, the form of the parameters of QPDFs when the group G is cyclic.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.210-214
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• 2005

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, Because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.

• Fibers and Polymers
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• 제7권2호
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• pp.164-168
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• 2006

Three vat dyes have been applied to regular viscose rayon and their dyeing and wash fastness properties were evaluated. Particle size determination was undertaken to obtain information about the size of dye particles converted by a reducing agent, to see if dye particle size has an affect on dyeing properties of regular viscose rayon. It is observed that viscose rayon exhibits more dyeability with reducing agent concentrations between 5-7.5 g/l. Also, we found that the vat dyeing system is greatly affected by the particle size of the vat dye converted to leuco form by a reducing agent.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.54.2-54.2
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• 2012

Solid-state dewetting of thin films is a process through which continuous solid films decay to form islands. Dewetting of thin films has long been a critical issue in microelectronics and much effort has been made to prevent the process and enhance the stability of films. On the other hand, dewetting has also been purposely induced to create arrays of particles and other structures for applications, including plasmonic structures and catalysts for growing nanotube and nanowire. We have investigated ways of producing regular structures via templated dewetting of thin films. Mainly, two different approaches have been used in our works to template dewetting of thin films: periodic topographical templating and planar patterning of epitaxially-grown films. Dewetting of topographically-patterned thin films results in the formation of nanoparticle arrays with spatial and crystallographic orders. Morphological evolution during templated-dewetting of single crystal films occurs in deterministic ways because of geometric and crystallographic constraints, and leads to the formation of regular structures with smaller sizes and more complex shapes than the initial patches. These results will be reviewed in this presentation.

• Animal cells and systems
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• 제6권4호
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• pp.283-285
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• 2002

Sponges of the family Irciniidae are poorly known in Korean waters. This paper describes a new species of new genus, Bergquistia coreana n. sp. in the family Irciniidae (Demospongiae: Dictyoceratida) from Jejudo Island, Korea from 1998 to 1999. Bergquistra n. gen. is characterized by extremely simple fasciculated and uncored primary fibres. However, in the choano-somal region, primary fibres are made of wider clear web. Secondary fibres form a very thin regular uncored network. The sponge surface has thick and regular conules. The colour is beige throughout the sponge, and the texture is slightly hard and compressible. Thickness of filament is variable.

• 한국영재학회:학술대회논문집
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• 한국영재학회 2002년도 춘계학술세미나 및 워크샵 21세기 창의적 생산자 양성을 위한 영재 교육
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• pp.9-30
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• 2002

A 4-year joint research project (1999-2003), entitled "The Development of Multiple Talents (DMT)", has been designed and carrying out under the sponsorship of the National Science Council, R.O.C. (Taiwan). A 3-dimension construct is proposed for the DMT: form of talents (10 forms, mainly based on Gardner′s theory of multiple intelligences), function of talents (3 functions, based on Stemberg′s conception of successful intelligence), and developmental stage (4 stages, from pre-school to senior high). To take an example of its empirical studies, Wu and Chien (2000), based on a renovated conception of personal intelligence, developed the "Personal Intelligence Inventory" (PII). By means of the PII, it was found that there were some personal intelligence differences between gifted and regular pupils: however, gifted group was not as superior as on academic performance to the regular one (Wu '||'&'||' Chien, 2000). It was also found that there were significant relationships between pupils′personal intelligence and school adjustment in both groups (Tsai '||'&'||' Wu, 2000).

• 정보저장시스템학회논문집
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• 제2권2호
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• pp.111-116
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• 2006

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.