• 한국전자파학회논문지
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• 제22권3호
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• pp.389-398
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• 2011

본 논문에서는 Ka 대역 위상 배열 레이더용 송수신(T/R: Transmit/Receive) 모듈의 설계 및 제작을 보였다. Ka 대역 송수신 모듈 구성 시 Ka 대역의 특수성을 고려하여 5비트(bit) 위상천이기와 5 비트 30 dB 디지털 가변감쇠기를 송수신 공통으로 사용하였으며, 서큘레이터는 T/R 모듈 외부에 부착되는 형태로 구성하였다. 단위 안테나 당 송신 출력은 1 W 이상 잡음 지수는 8 dB 미만으로 설정하였으며, 설계된 T/R 모듈의 RF부의 크기는 $5\;mm{\times}4\;mm{\times}57\;mm$로 소형화를 달성하였다. 설계된 T/R 모듈을 구현하기 위하여 T/R 모듈에 소요되는 개별 MMIC 검증 후 단위 T/R 모듈을 검증하는 방법을 사용하였다. 제작된 T/R 모듈은 설계 시 예측한 바와 같이 단위 T/R 모듈의 입력 5 dBm에서 출력 30 dBm 이상을 보였으며, 수신부는 잡음 지수 8 dB 미만, 이득 20 dB 이상을 얻었다.

• 호남수학학술지
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• 제33권3호
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• pp.419-424
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• 2011

Let D be an integral domain, Spec(D) the set of prime ideals of D, and X a subspace of the Zariski topology on Spec(D). We show that X is compact if and only if given any ideal I of D with $I{\nsubseteq}P$ for all $P{\in}X$, there exists a finitely generated idea $J{\subseteq}I$ such that $J{\nsubseteq}P$ for all $P{\in}X$. We also prove that if D = ${\cap}_{P{\in}X}D_P$ and if * is the star-operation on D induced by X, then X is compact if and only if * $_f$-Max(D) ${\subseteq}$X. As a corollary, we have that t-Max(D) is compact and that ${\mathcal{P}}$(D) = {P${\in}$ Spec(D)$|$P is minimal over (a : b) for some a, b${\in}$D} is compact if and only if t-Max(D) ${\subseteq}\;{\mathcal{P}}$(D).

• 대한간호학회지
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• 제41권2호
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• pp.157-164
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• 2011

Purpose: This study was performed to identify changes in blood glucose at preoperative fasting time in surgical patients over 60 yr. Methods: Data collection was performed from July, 2008 through July, 2009. Participants consisted of 80 nondiabetic surgical patients. Blood glucose was checked from 3 to 5 times. The 5 times were 2-hr fasting on the pre-operative day (T1, n=80), 8 hr (T2, n=80), 10 hr (T3, n=17), 12 hr (T4, n=34) and 14 hr fasting on the day of the operation (T5, n=29). Results: Of the patients, 27.5% had a blood glucose level of less than 79 mg/dL at T2; 17.6% at T3; 32.4% at T4; and 17.2% at T5. Mean blood glucose levels were 93.8 mg/dL at T1; 88.4 mg/dL at T2; 91.7 mg/dL at T3; 87.4 mg/dL at T4: and 94.1 mg/dL at T5. Blood glucose was the lowest at T2 (p<.001). Conclusion: As 17.6-32.4% of the patients showed the blood glucose level of less than 79 mg/dL at 8-14 hr pre-operative fasting, the authors recommend that surgical patients p>60 yr-of-age be observed for hypoglycemia during pre-operative fasting of more than 10 hr and that surgical patients >60 yr-of-age with risks for hypoglycemia be scheduled for operation within 10 hr preoperative fasting.

• 경영과학
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• 제16권1호
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• pp.63-74
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• 1999

This paper presents a R&D investment model for the Information and telecommunications(l&T) technology using multiple objective linear programming(MOLP). The MOLP model involves the simultaneous maximization of three linear objective functions associated with three criteria, which are social, technological, and economic criterion. This model is different from the traditional one which only involves the maximization of economic criterion. It yields a suitable R&D investment ratio to each technology field. Its application to the National R&D Project in l&t Industry is also presented. In this application, the Analytic Hierarchy Process(AHP) is proposed to estimate the weights, which used as the coefficients in each objective function of the MOLP model. Then the problem is solved using the interactive method STEM. It is showed that with the aid of STEM, the MOLP model can be useful decision aid in formulation R&D investment plan in l&t industry. It is expected that the MOLP model works as the basis for planning R&D investment strategy in l&T industry.

• 대한수학회논문집
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• 제9권2호
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• pp.423-438
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• 1994

We employ the Galerkin method to solve the nonlinear Urysohn integral equation (1.1) x(t) = f(t) ＋ $∫_{D}$ k(t, s, x(s))ds (t $\in$ D), where D is a bounded domain in $R^{d}$ , the function f and k are known and x is the solution to be determined. We assume that D has a locally Lipschitz boundary ([1, p. 67]). We can rewrite (1.1) in operator notation as x = f ＋ Kx. We consider (1.1) as an operator equation on $L_{\infty$}$(D) and assume that K is defined on the closure $\Omega$ of a bounded open set $\Omega$ ⊂ $L_{\infty}$(D). Throughout our analysis we put the following assumptions on (1.1).(omitted)(1.1).(omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.201.3-201.3
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• 2003

The ethanol extract from the fruit of Terminalia chebula (Combretaceae) and the hook of Uncaria sinensis (Rubiaceae) exhibited significant inhibitory activity on oxidative stress and the age-dependent shortening of the telomeric DNA length. In the peroxidation model using t-BuOOH, human epidermal keratinocytes-neonatal foreskin (HEK-N/F) cells were treated with the T. chebula and U. sinensis extracts. The results showed a notable enhancing effect on the cell viability of 60.5 ${\pm}$ 3.8 and 65.0 ${\pm}$ 3.0%, respectively, by 50 $\mu\textrm{g}$/ml of the extracts. (omitted)

• 대한수학회지
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• 제53권2호
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• pp.447-459
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• 2016

Let D be an integral domain, {$X_{\alpha}$} be a nonempty set of indeterminates over D, and $D{\mathbb{[}}\{X_{\alpha}\}{\mathbb{]}_1}$ be the first type power series ring over D. We show that if D is a t-SFT $Pr{\ddot{u}}fer$ v-multiplication domain, then $D{\mathbb{[}}\{X_{\alpha}\}{\mathbb{]}}_{1_{D-\{0\}}}$ is a Krull domain, and $D{\mathbb{[}}\{X_{\alpha}\}{\mathbb{]}}_1$ is a $Pr{\ddot{u}}fer$ v-multiplication domain if and only if D is a Krull domain.

• 대한수학회논문집
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• 제12권4호
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• pp.895-904
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• 1997

Let B(z) be a power series with operator coefficients where multiplication by B(z), T, is a contractive and everywhere defined transforamtion in the square summable power series. Then there is a Julia operator U for T such that $$ U = (T D)(\tilde{D}^* L) \in B(H \oplus D, K \oplus \tilde{D}), $$ where D is the state space of a conjugate canonical linear system with transfer function B(z).

• 대한수학회보
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• 제43권4호
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• pp.831-839
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• 2006

By relaxing the requirements for a sequence of functions to be a delta sequence, a space of Boehmians on the torus ${\beta}(T^d)$ is constructed and studied. The space ${\beta}(T^d)$ contains the space of distributions as well as the space of hyperfunctions on the torus. The Fourier transform is a continuous mapping from ${\beta}(T^d)$ onto a subspace of Schwartz distributions. The range of the Fourier transform is characterized. A necessary and sufficient condition for a sequence of Boehmians to converge is that the corresponding sequence of Fourier transforms converges in $D'({\mathbb{R}}^d)$.

• 산업경영시스템학회지
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• 제44권3호
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• pp.248-261
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• 2021

Scientific and technological performances (e.g., patents and publications) made through R&D play a pivotal role for national economic growth. National governments encourage academia-industry cooperation and thereby pursue continuous development of science technology and innovation. Increasing R&D-related investments and manpower are crucial for national industrial development, but evidence of poor performance in business performance, efficiency, and effectiveness has recently been found in Korea. This study evaluates performance efficiency of the 6T sector (Information Technology, Bio Technology, Nano Technology, Space Technology, Environment Technology, Culture Technology), which is considered a high-potential promising industry for the next generation growth and currently occupies two thirds of the national R&D projects. The study measures the relative efficiency of R&D in a comparative perspective by employing the Data Envelopment Analysis (DEA) method. The result reveals overall low efficiency in basic R&D (0.2112), applied R&D (0.2083), development R&D (0.2638), and others (0.0641), confirming that economic performance and efficiency were relatively poor compared to production efficiency. Efficient R&D needs policy makers to create strategies that can increase overall efficiency by improving productivity performance and quality while increasing economic performance.