• Current Optics and Photonics
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• 제3권3호
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• pp.243-247
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• 2019

We have developed a compact, wavelength-selectable, Q-switched Nd:YAG laser at mid ultraviolet for chemical warfare agent detection. The fundamental wave at 1064 nm is delivered by a pulsed solid state laser incorporating with a square-type Nd:YAG rod in a resonator closed by two crossed Porro prisms for environmental reliability. The output energy at 213 nm ($5{\omega}$) and 266 nm ($4{\omega}$) by ${\chi}^{(2)}$ process in the sequentially disposed BBO crystals are measured to be 6.8 mJ and 15.1 mJ, respectively. The output wavelength is selected for $5{\omega}$ and $4{\omega}$ by a motorized wavelength switch. The energy ratio of the $5{\omega}$ to the $4{\omega}$ is varied from 0.05 to 0.85 by controlling the phase matching temperature of the nonlinear crystal for sum-frequency generation without change of the output pulse parameters.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.36-39
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• 2017

길이가 같은 두 문자열의 같은 위치에 있는 문자의 순위가 모두 일치할 때, 두 문자열은 순위동형이라 한다. 순위다중패턴매칭문제는 텍스트 T와 k개의 패턴들의 집합 $P^{\prime}=\{P_1,P_2{\ldots},P_k\}$이 주어졌을 때, P'의 패턴들과 순위동형인 T의 모든 부분문자열의 위치를 찾는 문제이다. 최근 전처리단계에서 P'에 대한 이동테이블을 O(kmqlogq) 시간에 계산하여 순위다중패턴매칭문제를 해결하는 해싱기반 알고리즘이 제시되었다. 이때 P'에서 가장 짧은 패턴의 길이를 m, q-그램의 길이를 q라고 한다. 본 논문에서는 P'이 주어졌을 때, 이동테이블을 O(mqlogq) 시간에 계산하는 병렬알고리즘을 제시한다. 실험결과, 본 논문에서 제시하는 병렬알고리즘은 k개의 스레드를 이용하여 m=100, q=5에 대해 k=100일때와 k=1,000일 때 순차알고리즘보다 각각 약 12.9배, 약 215배 빠른 수행시간을 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.60-60
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• 2008

We manufactured Liquid Crystal Polymer (LCP) and (1-x)$BaTiO_3-xSrTiO_3$(BST) ceramic composites and investigated dielectric properties to use as embedded capacitor in printed circuit boards and replace LTCC substrates. The dielectric properties of these composites are varied with volume fraction of BST and ratios of BT/ST. Dielectric constants are in the range of 3~28. In addition, we could get low TCC and High Q value that could not achieve in other ceramic-polymer composites. Especially, in composite with x=0.4 and 50vol% BST, the dieletric constant and Q-value are 27 and 300, respectively. And more TCC is -116~145ppm/$^{\circ}C$ in the temperature range of -55~$125^{\circ}C$. We think that this composites can be used high-Q substrate material like LTCC and embedded temperature compensation capacitor in printed circuit boards.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.232-233
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• 2007

We manufactured Liquid Crystal Polymer (LCP) and (1-x)CaTiO3-xLaAlO3 (CT-LA) ceramic composites and investigated dielectric properties to use as embedded capacitor in printed circuit boards and replace LTCC substrate. The dielectric properties of these composites are varied with volume fraction of CT-LA and ratios of CT/LA. Dielectric constants are in the range of 3~15. In addition, we could get low TCC and High Q value that could not achieve in other ceramic-polymer composites. Especially, in composite with x=0.01 and 30 vol% CT-LA, the dieletric constant and Q-value are 10 and 200, respectively. And more TCC is $-28{\sim}300ppm/^{\circ}C$ in the temperature range of $-55{\sim}125^{\circ}C$. We think that this composites can be used high-Q substrate material like LTCC and embedded temperature compensation capacitor in printed circuit boards.

• 한국의류학회지
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• 제47권4호
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• pp.593-608
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• 2023

This study attempted to classify the types of perceptions of the new Hanbok, focusing on female college students in their 20s, and to analyze the characteristics of each type. This study was conducted with the Q methodology and analyzed with the QUANL pc program. The perceptions of the new Hanbok among female college students in their 20s were classified into four types: Type 1: modern/practical, Type 2: convenient/practical, Type 3: temporary/accessible, and Type 4: convenient/traditional. Type 1 emphasized the selection of Western clothing fabric, matching zipper/buttons, and achromatic colors. Type 2 highlighted a design that can be worn as daily clothing by combining materials that are convenient for laundering. Type 3 stressed the operation of new Hanbok rental stores so that it is easy to access and accept new Hanboks in old palaces and Hanok villages. Type 4 required the development of a design that reflects the elements of the traditional Hanbok and is convenient for activity and laundering.

• ETRI Journal
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• 제26권4호
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• pp.292-296
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• 2004

In this paper we present a new current-mode electronically tunable universal filter using only plus-type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions - all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters $\omega_0$ and $\omega_0/Q$. No element matching conditions are imposed. Both its active and passive sensitivities are low.

• 한국전자파학회논문지
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• 제29권4호
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• pp.266-269
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• 2018

본 논문에서는 Q 대역에서 사용가능한 무인항공기 라디오미터 응용 소형 도파관-마이크로스트립 전이구조를 제안하였다. 제안된 전이구조는 간단하면서도 소형이며, 쉽게 정합이 되고, 크기와 제작 오차에 덜 민감한 특징을 가진다. E 평면 패치형태를 가지는 제안된 전이구조는 캐비티 장착뿐 아니라, 도파관-마이크로스트립 기판의 정렬오차에도 덜 민감한 것이 특징이다. 주요파라미터의 최적화에는 3차원 시뮬레이터인 ANSYS사의 HFSS를 사용하였다. Back-to-back 구조에 대하여 중심 주파수에서 20 dB 이상의 반사손실과 1 dB 이하의 삽입손실을 가졌으며, 36 GHz에서 42 GHz까지 반사손실 15 dB 이상의 우수한 성능을 가졌다.

• 분석과학
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• 제30권6호
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• pp.379-389
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• 2017

In this study, we set up an analytical method that can be used for rapid and accurate determination of representative isoquinoline alkaloids in medicinal plants using UPLC-ESI-Q-TOF MS (ultra pressure liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry). The compounds were eluted on a C18 column with 0.1 % formic acid and acetonitrile, and separated with good resolution within 13 min. Each of the separated components was characterized by precursor ions (generated by ESI-Q-TOF) and fragment ions (produced by collision-induced dissociation, CID), which were used as a reliable database. We also performed method validation: analytes showed excellent linearity ($R^2$, 0.9971-0.9996), LOD (5-25 ng/mL), LOQ (17-82 ng/mL), accuracy (91.6-97.4 %) as well as intra- and inter-day precisions (RSD, 1.8-3.2 %). In the analysis of Chelidonium majus L., magnoflorine, coptisine, sanguinarine, berberine and palmatine were detected by matching retention times and characteristic fragment ion patterns of reference standards. We also confirmed that, among the quantified components, coptisine was present in the highest quantity. Furthermore, alkaloid profiling was carried out by analyzing the fragment ion patterns corresponding to peaks of unknown components. In this manner, protopine, chelidonine, stylopine, dihydroberberine, canadine, and nitidine were tentatively identified. We also proposed the molecular structure of the fragment ions that appear in the mass spectrum. Therefore, we concluded that our suggested method for the determination of major isoquinoline alkaloids by UPLC-Q-TOF can be useful not only for quality control, but also for rapid and accurate investigation of phytochemical constituents of medicinal plants.

• 한국지열·수열에너지학회논문집
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• 제4권1호
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• pp.11-19
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• 2008

Groundwater flow in confined aquifer and heat transport in underground geologic media are using same governing equation(line source) like well fuction. Therefore the conventional slope method using only later data obtained from in-situ thermal response test to determine the thermal conductivity of vertical geothermal heat exchanger(GHEX) is basically identical with one of Theis straight line method of aquifer test under artesian condition. In case that the pumping rate(Q, $m^3$/d) and drawdown(s,m) which are used for input data of existing hydrogeologic computer programs for aquifer test are replaced and converted to supplying heat energy per unit length of bore hole(Q/L,w/m or Kcal/h.m) and temperatures (T,$^{\circ}C$)measured at in and out-let of GHEX as in put data respectively, thermal conductivity around geothermal heat exchanger can be easily estimated without any special modification of the existing hydrogeologic computer program. Two numbers of time series temperature variation data obtained from in situ geothermal response test are analized using Theismethods(standard curve and straight line method) by using existing aquifer test program and conventional Slope method proposed by ASHRAE. The results show that thermal conductivity values estimated by two straight methods are identical and the difference of estimated values between standard curve methods and Slope method are also within acceptable ranges. In general,the thermal conductivity estimated from Theis straight linemethod gives more accurate value than the one of Slope method due to that Slope method uses only visual matching otherwise Theis method uses automatic curve matching estimation with reducing RSS.

• 한국전자파학회논문지
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• 제27권1호
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• pp.20-26
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• 2016

본 논문에서는 GaN-HEMT를 이용하여 X-대역에서 동작하는 이단으로 구성된 전력증폭기를 설계 및 제작하였다. 높은 전력 이득을 얻기 위해 간단한 구조의 중간 단 정합 네트워크를 통해 이단으로 구성하였다. 3D EM 시뮬레이션을 통하여 본드와이어 인덕턴스와 기생 캐패시턴스를 예측하였다. 본드와이어 인덕턴스를 줄임으로써 정합 네트워크의 Q(quality-factor)를 최소화하여 대역 특성을 향상시켰다. 제작된 전력증폭기는 40 V의 동작 전압을 인가하였으며, 8.1~8.5 GHz에서 16 dB 이상의 전력 이득, 42.5 dBm 이상의 출력 전력, 35 % 이상의 효율 특성을 나타냈다.