• 한국학교수학회논문집
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• 제3권2호
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• pp.59-67
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• 2000

Two groups of students, who are the students in the natural science course of high school in Korea, learned the equation of figure in space (point, line, plane) to understand more effectively with two different textbooks. One group was taught with the textbook used now in most high schools and the other group was taught with the textbooks systematized by associating old concept with new concept. The results are as follows : 1) We need understand the basic concept of vector plainly and flexibly to apply it to the solution of problems. 2) It helps students understand new concepts how we should establish the concept about point, line and plane in space by applying the concept about those on XY plane, 3) It is very effective in understanding the new knowledge system more easily to analyze the existent concepts and to arrange them systematically for efficient understanding of new concepts. 4) The texts which consist of contents organized by basic concepts improve students' learning ability.

• 정보처리학회논문지A
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• 제9A권1호
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• pp.99-104
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• 2002

본 논문에서는 벡터공간 $R_n$에서 정의된 Bezier곡선과 Bezier곡면을 Lie군(Lie group)에서 확장하는 일반적인 새로운 생성방법을 제시한다. 이 방법에 의해서 생성된 Bezier곡선과 Bezier곡면은 Lie군의 성질에 의해서 미분 가능한 구조를 갖는다. 이 방법은 공간상에서 움직이는 물체에 대한 부드러운 움직임을 묘사하거나 궤도생성에 사용할 수 있다.

• 한국멀티미디어학회논문지
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• 제25권6호
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• pp.783-792
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• 2022

Versatile Video Coding (VVC) is the latest video coding standard, which had been developed by the Joint Video Experts Team (JVET) of ITU-T Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG) in 2020. Although VVC can provide powerful coding performance, it requires tremendous computational complexity to determine the optimal block structures during the encoding process. In this paper, we propose a fast ternary tree decision method using two neural networks with 7 nodes as input vector based on the multi-layer perceptron structure, names STH-NN and STV-NN. As a training result of neural network, the STH-NN and STV-NN achieved accuracies of 85% and 91%, respectively. Experimental results show that the proposed method reduces the encoding complexity up to 25% with unnoticeable coding loss compared to the VVC test model (VTM).

• Journal of Dairy Science and Biotechnology
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• 제29권1호
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• pp.49-54
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• 2011

담즙산 분해효소(Bile salt hydrolase, EC 3.5.1.24) 활성은 담즙산의 카르복실기와 결합되어 있는 아미노기(glycine or taurine)와의 amide 결합을 끊는 작용을 하며, 이 효소 활성은 사람이나 동물의 장내 미생물들에서 널리 분포하고 있다. 노인 분변으로부터 분리한 여러 균주의 Enterococcus faecalis중에서 BSH activity가 가장 높은 CU30-2를 선발하였다. BSH 유전자를 pET22b expression vector에 클로닝하여 Escherichia coli BL21(DE3) Gold를 이용하여 단백질을 발현하였다. 6x His-tag이 있는 BSH 효소를 $Ni^+$-NTA agarose column을 이용하여 분리 정제하였고, 6가지의 다른 담즙산염을 이용하여 기질 특이성을 비교하였다. E. faecalis CU30-2의 BSH 효소는 glycine이 결합된 담즙산염에 대한 효소활성이 taurine이 결합된 것에 대한 활성보다 약 50배 정도 높게 나타났다. 이 효소의 최적 pH와 온도는 각각 7.0과 40$^{\circ}C$로 확인되었다.

• 한국지능시스템학회논문지
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• 제23권1호
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• pp.7-11
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• 2013

전문가의 지식을 기반으로 한 추천시스템에 대한 다양한 연구가 최근 활발히 진행되고 있다. 지금까지의 전문가 기반 추천 시스템이 공통된 전문가 그룹의 지식을 바탕으로 모두에게 아이템을 추천하였다면, 본 논문에서는 개인의 필요와 전문가에 대한 관점을 반영한 개인화된 전문가 그룹의 지식을 기반으로 한 추천 시스템을 제안한다. 개인화된 전문가 그룹을 찾는 과정이 제안하는 추천 시스템에서 가장 중요한 부분이다. 이를 위해 개인화된 전문가를 효율적으로 찾아내는 지지 벡터 머신(SVM) 기반 기법을 제안한다. 추천 시스템에서 널리 사용되는 k 근접이웃 알고리즘과의 비교를 통하여서 개인화된 전문가를 기반으로 한 협업 필터링 추천 시스템의 효용성을 입증한다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4161-4164
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• 2012

Density functional MO calculations for the methylsilole anion of $[C_4H_4SiMe]^-$ and methylgermole anion of $[C_4H_4SiMe]^-$ at the B3LYP (full)/6-311+$G^*$ level (GAUSSIAN 94) were carried out and characterized by frequency analysis. The ground state structure for the methylsilole anion and methylgermole anion is that the methyl group is pyramidalized with highly localized structure. The difference between the calculated $C_{\alpha}-C_{\beta}$ and $C_{\beta}-C_{\beta}$ distances are 9.4 and 11.5 pm, respectively. The E-Me vector forms an angle of $67.9^{\circ}$ and $78.2^{\circ}$ with the $C_4E$ plane, respectively. The optimized structures of the saddle point state for the methylsilole anion and methylgermole anion have been also found as a planar with highly delocalized structure. The optimized $C_{\alpha}-C_{\beta}$ and $C_{\beta}-C_{\beta}$ distances are nearly equal for both cases. The methyl group is located in the plane of $C_4E$ ring and the angle between the E-Me vector and the $C_4E$ plane for the methylsilole anion and methylgermole anion is $2.0^{\circ}$ and $2.3^{\circ}$, respectively. The energy difference between the ground state structure and the transition state structure is only 5.1 kcal $mol^{-1}$ for the methylsilole anion. However, the energy difference of the methylgermole anion is 14.9 kcal $mol^{-1}$, which is much higher than that for the corresponding methylsilole monoanion by 9.8 kcal $mol^{-1}$. Based on MO calculations, we suggest that the head-to-tail dimer compound, 4, result from [2+2] cycloaddition of silicon-carbon double bond character in the highly delocalized transition state of 1. However, the inversion barrier for the methylgermole anion is too high to dimerize.

• Korean Chemical Engineering Research
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• 제56권2호
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• pp.176-185
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• 2018

지구 온난화가 가속화됨에 따라 온실가스 감축이 보다 중요해졌다. 이산화탄소 건식 개질은 온실가스인 $CO_2$와 $CH_4$를 활용하여 부가가치가 높은 물질인 CO와 $H_2$를 얻을 수 있는 유망한 온실가스 감축 기술이다. 그러나 이 반응이 일어나는 반응기의 운전 중에 심각한 코킹 문제가 발생할 수 있다. 이산화탄소 개질반응은 매우 강한 흡열반응이기 때문에 반응기 입구 근처에서 반응 온도가 많이 떨어지면서 코크 생성을 야기시킨다. 이러한 문제를 해결하기 위해서는 코크 생성이 잘 일어나지 않는 온도영역에서 반응이 일어나도록 하는 것이 중요하다. 본 연구에서는 새로운 촉매 배열 방법을 이용하여 반응기 전 구간이 코크 생성이 잘 일어나지 않는 온도 영역 내에서 유지되도록 하는 설계 방법을 제안하였다. 이 설계 방법은 연료 유량, 촉매 밀도, 구간 별 출구 온도를 최적화 변수로 하여 주어진 전환율에 대하여 반응기 길이를 최소화 할 수 있는 최적화 문제를 풀도록 하여 반응기를 최적화한다.

• Clinical and Experimental Reproductive Medicine
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• 제49권4호
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• pp.248-258
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• 2022

Objective: This research investigated the effects of human chorionic gonadotropin (HCG)-producing peripheral blood mononuclear cells (PBMCs) on the implantation rate and embryo attachment in mice. Methods: In this experimental study, a DNA fragment of the HCG gene was cloned into an expression vector, which was transfected into PBMCs. The concentration of the produced HCG was measured using enzyme-linked immunosorbent assay. Embryo attachment was investigated on the co-cultured endometrial cells and PBMCs in vitro. As an in vivo experiment, intrauterine administration of PBMCs was done in plaque-positive female mice. Studied mice were distributed into five groups: control, embryo implantation dysfunction (EID), EID with produced HCG, EID with PBMCs, and EID with HCG-producing PBMCs. Uterine horns were excised to characterize the number of implantation sites and pregnancy rate on day 7.5 post-coitum. During an implantation window, the mRNA expression of genes was evaluated using real-time polymerase chain reaction. Results: DNA fragments were cloned between the BamHI and EcoRI sites in the vector. About 465 pg/mL of HCG was produced in the transfected PBMCs. The attachment rate, pregnancy rate, and the number of implantation sites were substantially higher in the HCG-producing PBMCs group than in the other groups. Significantly elevated expression of the target genes was observed in the EID with HCG-producing PBMCs group. Conclusion: Alterations in gene expression following the intrauterine injection of HCG-producing PBMCs, could be considered a possible cause of increased embryo attachment rate, pregnancy rate, and the number of implantation sites.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권4호
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• pp.268-276
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• 2015

A ship's sailing route or plan is determined by the master as the decision maker of the vessel, and depends on the characteristics of the navigational environment and the conditions of the ship. The trajectory, which appears as a result of the ship's navigation, is monitored and stored by a Vessel Traffic Service center, and is used for an analysis of the ship's navigational pattern and risk assessment within a particular area. However, such an analysis is performed in the same manner, despite the different navigational environments between coastal areas and the harbor limits. The navigational environment within the harbor limits changes rapidly owing to construction of the port facilities, dredging operations, and so on. In this study, a support vector machine was used for processing and modeling the trajectory data. A K-fold cross-validation and a grid search were used for selecting the optimal parameters. A complicated traffic route similar to the circumstances of the harbor limits was constructed for a validation of the model. A group of vessels was composed, each vessel of which was given various speed and course changes along a specified route. As a result of the machine learning, the optimal route and voyage data model were obtained. Finally, the model was presented to Vessel Traffic Service operators to detect any anomalous vessel behaviors. Using the proposed data modeling method, we intend to support the decision-making of Vessel Traffic Service operators in terms of navigational patterns and their characteristics.

• Biomolecules & Therapeutics
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• 제5권1호
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• pp.53-58
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• 1997

$[Lys^7$]dermorphin, abbreviated K7DA, which has structural features similar to a metabolically stable $\mu$-opioid peptide agonist $[D-Arg^2, Lys^4$]dermorphin analogue (DALDA), but is intrinsically more potent with respect to binding to the $\mu$-opioid peptide receptor. The present studies report on attempts to enhance brain uptake of systemically administered K7DA by conjugation to a complex of streptavidin (SA) and the OX26 murine monoclonal antibody to the rat transferrin receptor, which undergoes receptor-mediated transcytosis through the blood-brain barrier (BBB). SA-OX26 conjugate mediates BBB transport of biotinylated therapeutics. The K7DA is monobiotinylated at the $\varepsilon$-amino group of the $[Lys^7$] residue with cleavable linker using NHS-SS-biotin. The brain uptake of $^{125}I$ labeled biotinylated K7DA ($^{125}I$-bio-SSa-K7DA) was very small and rapidly metabolized after intravenous injection. The brain uptake, expressed as percent of injected dose delivered per gram of brain, of the $^{125}I$-bio-55-K7DA bound to the SA-OX26 conjugate $^{125}I$-bio-SS-K7DA/SA-OX26) was 0.14$\pm$0.01, a level that is 2-fold greater than the brain uptake of morphine. The cleavability of the disulfide linker in vivo in rat plasma and brain was assessed with gel filtration HPLC and intravenous injection of labeled opioid chimeric peptides. The disulfide linker is stable in plasma in vivo but is cleaved in rat brain in vivo. In conclusion, these studies show that delivery of these potential opioid peptides to the brain may be improved by coupling them to vector-mediated BBB drug delivery system.