• 대한수학회지
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• 제35권1호
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• pp.23-76
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• 1998

We prove that a non-empty separable metrizable space X admits a totally bounded metric for which the metric dimension of X in Assouad's sense equals the topological dimension of X, which leads to a characterization for the latter. We also give a characterization based on this Assouad dimension for the demension (embedding dimension) of a compact set in a Euclidean space. We discuss Assouad dimension and these results in connection with porous sets and measures with the doubling property. The elementary properties of Assouad dimension are proved in an appendix.

• 한국광학회지
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• 제11권4호
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• pp.294-298
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• 2000

반도체레이저로 단면 여기시킨 Nd:VAP 레이저의 내부공진기 제2고조파 출력특성을 조사하였다. 유도방출 단면적과 형광수명의 곱이 커 낮은 발진문턱 특성을 갖는 Nd:S-VAP 매질은 컴팩트한 마이크로칩 레이저에 적합하다. 내부공진기를 이용한 제2고조파 발진문턱에너지가 81 uJ로 측정되어 쉽게 발진됨을 확인하였다. 여기에너지 $2\mu\textrm{J}$에서 제2고조파 에너지 $126\mu\textrm{J}$을 얻었고, 내부공진기 제2고조파의 출력을 계산하여 이론적인 해석 근거를 제시하였다. Q-스위치된 제2고조파 출력은 펄스폭 26ns에 펄스당 에너지 $15\mu\textrm{J}$로 저출력에서도 시.공간적으로 깨끗한 펄스를 얻었으며, $M^2$도 1.47로 우수한 빔 특성을 나타내었다.

• Journal of Information Science Theory and Practice
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• 제4권2호
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• pp.53-65
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• 2016

The authors in this paper aim to identify the growth of literature on Intellectual Property Rights (IPRs). The research publications on IPRs were downloaded from the Scopus online citation database and the authors found that there were 1,513,138 records contributed globally over a period of 10 years from 2005 to 2014. The distribution of publications based on the year, country, and document type were studied. Relative growth rate (RGR) of the publications and doubling time (T_d) were calculated. Most productive organizations, source titles, and the productive authors on IPR research were studied. Most cited articles in the study area were identified. The results show that a number of publications under the subjects Medicine and Engineering were produced. The developed countries are very active in IPR research and producing publications. It is found that one institution which holds the sixth place among the top 10 most productive institutions belongs to Brazil, a developing country. Two developing countries such as China and India hold second and tenth positions respectively in the top 10 countries contributing literature on IPRs.

• 대한수학회보
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• 제36권1호
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• pp.25-31
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• 1999

Let $\nu$ be a positive Borel measure on a space of homogeneous type (X, d, $\mu$), satisfying the doubling property. A condition on a weight $\omega$ for whixh a maximal operator $M\nu f$(x) defined by M$mu$f(x)=supr>0{{{{ { 1} over {ν(B(x,r)) } INT _{ B(x,r)} │f(y)│d mu (y)}}}}, is of weak type (p,p) with respect to (ν, $omega$), is that there exists a constant C such that C $omega$(y) for a.e. y$\in$B(x, r) if p=1, and {{{{( { 1} over { upsilon (B(x,r) } INT _{ B(x,r)}omega(y) ^ (-1/p-1) d mu (y))^(p-1)}}}} C, if 1$infty$.

• 한국의류산업학회지
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• 제5권4호
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• pp.408-412
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• 2003

The micro structure of POY was modified and a wool-like touch yarn of composite fibers with different shrinkage was made. With this yarn 12 different fabrics with wool like touch were prepared. The characteristic physical property changes of the fabrics examined are as follows: 1. In all cases, the initial high shrinkage stages were observed in hot water treatment and the 3D images of complex multilayer of typical doubling fibers with different shrinkage were also observed in hot air treatment of 170C. 2. The tensile strength changes of satin and plain fabrics with the change of twist count showed similar behavior. However, WT's were slightly higher and RT's was lower in twill and satin fabrics than those in plain fabric. 3. Since a slight decrease of B's of twill fabric found with increasing twist count under given experimental condition, it could be influenced on the anti-drape stiffness was decreased and flexibility was increased. 4. A significant decrease of G values was observed in the twist count 800-1000 T.P.M However, in the twist count higher than 1000 T.P.M G values observed were kept nearly constant. 5. MIU of plain and twill fabrics showed a drastic decrease at the twist count higher than 1000 T.P.M.

• 한국표면공학회지
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• 제56권5호
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• pp.309-319
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• 2023

Non-woven fabric is a textile product made by spinning thermoplastic polymers without manufacturing processes such as stretching, doubling, twisting, weaving, and knitting to form a sheet-shaped web in which fibers are tangled with each other, and then combining them by mechanical and physical methods. In addition, the non-woven fabric manufacturing process has various raw material choices, high productivity, so it is a textile manufacturing technology that can have various uses and increase added value. This study was conducted to control the shape and physical properties of products by improving the manufacturing method of melt-blown non-woven fabrics using process technology that easily changes the shape of non-woven fabrics and improves mechanical properties. In particular, it is considered that a non-woven fabric with a thin material shape and improved mechanical properties will be easily applied to a continuous secondary battery manufacturing industry such as roll to roll operation.

• 대한수학교육학회지:수학교육학연구
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• 제18권4호
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• pp.483-497
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• 2008

본 연구에서는 (두 자리 수)${\times}$(두 자리 수)의 곱셈에 대한 학생의 비형식적인 지식은 무엇이며, 문제 해결 과정에서 이러한 비형식적 지식의 역할이 어떠한지 분석하였다. 아직 (두 자리 수)${\times}$(두 자리 수)의 곱셈을 학습하지 않은 한 명의 3학년 학생을 대상으로 4차례의 임상면담을 실시하였고, 학생이 작성한 활동지와 행동적인 특성, 사고과정에 대한 단서 등도 자료에 포함시켰다. 아직 표준적인 알고리즘을 알지 못하는 상태에서 비형식적인 지식만으로 어떻게 문제를 해결하고 개념을 발전시키는지, 특히 어떤 유형의 비형식적인 지식을 어떤 방식으로 활용하는지 알아보았다. 관찰한 비형식적 지식은 모델 화하기, 두 배하기 전략, 그리고 곱셈의 분배와 결합 성질에 대한 이해이다. 그리고 비형식적 지식은 문제 해결 과정에서 해결방법을 설명하고 정당화하는 역할을 하였다.

• 한국식품과학회지
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• 제30권3호
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• pp.665-671
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• 1998

한국산 표고버섯(Lentinus edodes SR-1) 균사체를 액체배양한 후 균사체로부터 추출, 정제한 PBP의 항암효과 및 면역학적 특성에 대하여 실험하였다. PBP의 항암효과는 in vitro 배양에서 암세포의 배수시간을 2배로 연장하는 활성단위 1 unit은 mouse leukemic cell인 $P_{388}$과 $L_{1210}$의 경우 1 mg 정도였으며, 인체의 장암세포인 HCT-48, HRT-18, HT-29 및 간암세포인 Hep G2의 경우 각각 4.4, 3.6, 6.6, 2.6 mg이었다. 그리고 $P_{388}$과 $L_{1210}$의 경우 배지 1 mL당 4 mg 정도, HRT-18 및 HT-29, Hep G2의 경우 9 mg의 PBP를 첨가했을 때 암세포를 사멸시키는 것으로 나타났다. $P_{388}$과 $L_{1210}$, HCT-48, Hep G-2의 PBP 처리에 따른 암세포의 크기 분포도 변화는 PBP를 처리하지 않은 대조군에 비하여 시간이 경과함에 따라, 그리고 PBP의 농도가 증가함에 따라 비례적으로 적은 쪽으로 이동하였다. In vivo 실험에서 대조군보다 PBP를 첨가한 군에서 비장의 무게가 증가하였으며, 용혈반 형성실험에서 PBP를 투여한 군이 대조군에 비하여 항체 형성세포가 2배로 증가하였다.