• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.73-77
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• 2004

막분리 기술인 정밀여과와 한외여과는 물질의 크기 차에 따른 체분리 (sieving)를 기본 원리로 하기 때문에 분자수준에서의 선택적 물질분리가 어렵다는 문제점이 있다. 이러한 문제점을 해결하기 위한 대안으로서 분리막에 분자수준에서의 물질 선택성을 부여한 친화성 막(affinity membrane) 제조에 대한 연구가 활발히 이루어지고 있다.(중략)

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.175-178
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• 2006

본 논문에서는 주요성분분석과 상호정보 추정을 조합한 입력변수선택 기법을 제안하였다. 여기서 주요성분분석은 2차원 통계성을 이용하여 입력변수 간의 독립성을 찾기 위함이고, 상호정보의 추정은 적응적 분할을 이용하여 입력변수의 확률밀도함수를 계산함으로써 변수상호간의 종속성을 좀더 정확하게 측정하기 위함이다. 제안된 기법을 인위적으로 제시된 각 500개의 샘플을 가지는 6개의 독립신호와 1개의 종속신호를 대상으로 실험한 결과, 빠르고 정확한 변수의 선택이 이루어짐을 확인하였다.

• Analytical Science and Technology
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• v.16 no.4
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• pp.320-324
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• 2003

Acidic drug selective electrodes based on metal(II)-di-2-pyridyl ketone-acidic drugs ternary complex as electroactive material were prepared. The metal ions, $Fe^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$ were used. Nitrophenyl ether series were used as plasticizers. The electrodes exhibit a fast stable and linear response for $5{\times}10^{-5}{\sim}10^{-3}mol/L$ mefenamic acid (MA) in borate buffer solution (pH 8.9) and ibuprofen(Ib) in phosphate buffer solution (pH 7.0). The recovery test for mefenamic acid and ibuprofen using standard addition method were 99.0% and 98.4% with relative standard deviation of 2.4% and 2.6% respectively.

• Analytical Science and Technology
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• v.7 no.1
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• pp.25-31
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• 1994

As for analytes which did not represent the differences of the selectivity on the stationary and mobile phase, secondary chemical equilibrium theory was applied to study pH effects on the separation of alkylphenols. Mobile phase was consisted of an aqueous sodium carbonate-bicarbonate buffer and acetonitrile. The maximum selectivity for adjacent peak pairs was predicted from those values of $k^{\prime}_{HA}/k^{\prime}_{A-}$ and ${\Delta}pK$. The optimum pH determined by this method was 11.18 pH and solvent selectivity were considered at the same time to invoke the full range of selectivity effects possible for separations. Quaternary mixture composed of methanol, acetonitrile, tetrahydrofuran and water was adjusted to optimum pH 11.18. As the statistical simplex technique of an overlapping resolution map (ORM) was used to predict the optimized solvent system. The optimum solvent, which gives complete separation of alkylphenols, was determined as follws MeOH : ACN : THF = 14.4 : 81.8 : 2.8.

• Journal of the Korean association of regional geographers
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• v.16 no.2
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• pp.123-136
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• 2010

To grasp the migration characteristics in the Busan Metropolitan Area (BMA), this study analyzed household characteristics and migration selectivity. The major findings of the study are as follows: first, young (especially 25 to 34 years of age) and single person households have greater propensity to migrate out from BMA, and their home ownership rate is low. These trends are much stronger in households that migrate out towards the Seoul Metropolitan Area from Busan. Second, age and educational selectivity of migration is evident. The characteristics of movers are quite different from those of stayers at Busan. Young people are more likely to migrate out of Busan, and higher levels of education are deeply associated with higher mobility. Through analyzing four high schools in Busan, it is acknowledged that most honor students entered 4-year universities in Seoul. The outflow of highly educated young people may induce the brain drain. Busan is undergoing both population decline and the problems caused by the brain drain.

• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.160-170
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• 1995

The authors investigated feeding habit of river sculpin(C. poecilopus) were conducted at the Chiak streams from April 1993 to March 1994. The feeding habit of C. poecilopus was mainly acquatic insects, such as Ephemeroptera, Odonata, Plecoptera, Trichoptera, Coleoptera, Diptera, and Nematoda, teleost fishes, fish egg and terrestrial insects. Terrestrial insects in the stomach contents were found mainly in autumn, and teleost fish(Moroco oxycephalus) was in summer. Aquatic insects(Ephemeroptera, Trichoptera and Diptera) constituted the bulk of food items ingested during each season. The prey selection indices for Ephemeroptera were positively selected in summer, and negatively selected in autumn and winter, Tricoptera and Diptera were positively selected in autumn and winter, and negatively selected in summer. Additionally, analysis for stomach contents of guarding males suggests that the parental males eat their own eggs during egg guarding(filial-cannibalism).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1128-1137
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• 2012

In this paper, we propose an improved MPR selection method considering mobility and density of nodes for ad-hoc networks. In Optimized Link State Routing(OLSR), a node selects 1-hop Multi-Point Relay(MPR) nodes to cover all 2-hop neighbor nodes. In a high population area, many nodes are likely to be selected as MPR nodes by their neighbors. This leads to increase in contention among MPR nodes and may decrease overall performance of the network. In addition, when an MPR node leaves the communication range of its MPR selector node, it can no longer perform as the MPR node and the performance of the network may also decrease. In this paper, we propose an MPR selection method which measures the mobility and density of nodes by exchanging the hello messages and gives the priorities to the nodes for MPR selection. Performance evaluation results using OPNET show that the proposed method is superior to OLSR or the MPR candidate method in terms of connectivity and throughput.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.484-490
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• 1985

Gut contents of larval gunnels collected in Kyonggi Bay, Yellow Sea were examined in order to understand the feeding habit of the fish. There were some differences in the gut contents depending upon the body length of the fish. Most important food organisms were Copepoda followed by Appendicularia, fish eggs and Decapoda larvae. Although major food organisms were closely related to the size of zooplankton population, the fish showed a positive food selectivity for Copepoda with increasing body lengh, while there was a negative selectivity for Chaetognatha regardless of body length. However, there appeared to be no size preference on the food organisms by the larval gunnel.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.23-27
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• 1994

Nutrient culture study was initiated to examine the selectivity of dithiopyr(S, S-dimethyl 2-difluoromethyl)-4-(2-methylpropyl)-6-(trifluoro methyl)-3, 5-pyridine dicarbothiate) in rice(Oryza sativa L.) and barnyardgrass(Echinochloa crusgalli Beauv.). Absorption and translocation of $^{14}C$-dithiopyr in rice and barnyardgrass were also investigated to determine their selective mechanism. Rice was very tolerant, but barnyardgrass was susceptible to dithiopyr. The absorption of dithiopyr was greater in barnyardgrass than in rice and most of them remained in the roots of both species. Dithiopyr was absorbed by roots and basal shoots of both species. Translocation of dithiopyr was very low but was higher in barnyardgrass than in rice. Therefore, this study suggest that the selectivity of dithiopyr between rice and barnyardgrass may be mainly attributed to the absorption and translocation of dithiopyr in plants.

• Journal of the Korean Ceramic Society
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• v.40 no.11
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• pp.1073-1077
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• 2003

The Sn $O_2$-based gas sensors can detect inflammable and toxic gases of low concentration by the modulation of surface resistance, but they lack in selectivity on the whole. To give selectivity to the Sn $O_2$-based gas sensors, studies on the sensing mechanism, selective gas sensing materials and signal processing techniques are demanded. Ethanol (C$_2$ $H_{5}$OH) and acetonitrile ($CH_3$CN) were confirmed to undergo catalytic oxidation on Sn $O_2$ by gas chromatography. PdCl$_2$-doped Sn $O_2$ showed excellent sensitivity to ethanol and acetonitrile, while La$_2$ $O_3$-doped Sn $O_2$ showed excellent sensitivity to ethanol, but poor sensitivity to acetonitrile. Using these two sensors and pattern recognition, the selectivity to acetonitrile is greatly enhanced. The minimum detection level of acetonitrile was 15 ppm in air and 20 to 100 ppm when exposed to interfering gases together with acetonitrile.