CAS계 유리가 첨가된 CaCO₃-Al₂O₃ 혼합물 및 화합물의 저온 소결 및 유전 특성

윤상옥,김명수,김관수,Yoon, Sang-Ok,Kim, Myung-Soo,Kim, Kwan-Soo 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.5

Effects of ceramic filler types and dose on the low temperature sintering and dielectric properties of ceramic/$CaO-Al_2O_3-SiO_2$ (CAS) glass composites were investigated. All of the specimens were sintered at $850{\sim}900^{\circ}C$ for 2 h, which conditions are required by the low-temperature co-firing ceramic (LTCC) technology. Ceramic fillers of $CaCO_3$, $Al_2O_3$, $CaCO_3-Al_2O_3$ mixture, and $CaCO_3-Al_2O_3$ compound ($CaAl_2O_4$), respectively, were used. The addition of $Al_2O_3$ yielded the crystalline phase of alumina, which was associated with the inhibition of sintering, while, $CaCO_3$ resulted in no apparent crystalline phase but the swelling was significant. The additions of $CaCO_3-Al_2O_3$ mixture and $CaAl_2O_4$, respectively, yielded the crystalline phases of alumina and anorthite, and the sintering properties of both composites increased with the increase of filler addition and the sintering temperature. In addition, the $CaAl_2O_4$/CAS glass composite, sintered at $900^{\circ}C$, demonstrated good microwave dielectric properties. In overall, all the investigated fillers of 10 wt% addition, except $CaCO_3$, yielded reasonable sintering (relative density, over 93 %) and low dielectric constant (less than 5.5), demonstrating the feasibility of the investigated composites for the application of the LTCC substrate materials.

Zinc-borosilicate Glass Frit 첨가에 따른 Ca(Li_1/4Nb_3/4)O₃-CaTiO₃ 세라믹스의 마이크로파 유전 특성

윤상옥,김관수,조태현,심상흥,박종국,Yoon Sang-Ok,Kim Kwan-Soo,Jo Tae-Hyun,Shim Sang-Heung,Park Jong-Guk 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.6

$xCa(Li_{1/4}Nb_{3/4})O_{3}-(1-x)CaTiO_{3}$ ceramics were sintered under the presence of zinc-borosilicate(ZBS) glass and resultant microwave dielectric properties were investigated with a view to applying the composition to low-temperature co-fired ceramic(LTCC) technology. The addition of $5{\sim}15wt%$ ZBS glass ensured successful sintering below $900\;^{\circ}C$. In general, increased addition of ZBS glass increased sinterability but it decreased the quality factor($Q{\times}f_{0}$) significantly due to the formation of an excessive liquid and second phases. As for the addition of $CaTiO_3$, the dielectric constant(${\epsilon}_r$) and temperature coefficient of resonant frequency(${\tau}_f$) increased, while the quality factor($Q{\times}f_{0}$) did not show an apparent change. The sintered $0.9Ca(Li_{1/4}Nb_{3/4})O_{3}-0.1CaTiO_{3}$ specimen at $900\;^{\circ}C$ with 10 wt% ZBS glass demonstrated 39.6 in dielectric constant(${\epsilon}_r$), 4,400 in quality factor$(Q{\times}f_{0}),\;and\;-11ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_f$).

Lead-Borosilicate Glass계 LTCC용 유전체에 대한 고찰

윤상옥,오창용,김관수,조태현,심상흥,박종국,Yoon, Sang-Ok,Oh, Chang-Yong,Kim, Kwan-Soo,Jo, Tae-Hyun,Shim, Sang-Heung,Park, Jong-Guk 한국세라믹학회 2006 한국세라믹학회지 Vol.43 No.6

The effects of lead-borosilicate glass frits on the sintering behavior and microwave dielectric properties of ceramic-glass composites were investigated as functions of glass composition of glass addition ($10{\sim}50vol%$), softening point (Ts) of the glass, and sintering temperature of the composites ($500{\sim}900^{\circ}C$ for 2 h). The addition of 50 vol% glass ensured successful sintering below $900^{\circ}C$. Sintering characteristics of the composites were well described in terms of Ts. PbO addition in to the glass enhanced the reaction with $Al_{2}O_3$ to form liquid phase and $PbAl_{2}Si_{2}O_8$, which was responsible to lower Ts. Dielectric constant(${\epsilon}_r$), $Q{\times}f_0$ and temperature coefficient of resonant frequency (${\tau}_f$) of the composite with 50 vol% glass contents ($B_{2}O_{3}:PbO:SiO_{2}:CaO:Al_{2}O_3$ = 5:40:45:5:5) demonstrated 8.5, 6,000 GHz, $-70\;ppm/^{\circ}C$, respectively, which is applicable to substrate requiring a low dielectric constant. When the same glass composition was applied sinter $MgTiO_3\;and\;TiO_2,\;at\;900^{\circ}C$ (50 vol% glass in total), the properties were 23.8, 4,000 GHz, $-65ppm/^{\circ}C$ and 31.1, 2,500 GHz, $+80ppm/^{\circ}C$ respectively, which is applicable to filter requiring an intermidiate dielectric constant.

저온 소결용 xZnWO₄-(1-x)TiO₂ 세라믹스의 소결 및 마이크로파 유전 특성

윤상옥,김관수,심상흥,박종국,Yoon, Sang-Ok,Kim, Kwan-Soo,Shim, Sang-Heung,Park, Jong-Guk 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.9

Sinterability and microwave dielectric properties of $xZWO_{4}-(1-x)TiO_{2}$ ceramic systems with zinc-borosilicate glass and $TiO_{2}$ contents for LTCC(Low Temperature Co-fired Ceramics) were investigated. The addition of $3{\sim}10\;wt%$ ZBS glass ensured the sinterability below $900^{\circ}C$. In general, increasing ZBS glass content seemed to enhance the sinterability, but the quality factor($Qxf_{0}$) significantly decreased due to the formation of an excessive liquid and second phases. As for the addition of $TiO_{2}$, the dielectric constant(${\varepsilon}_{r}$) and temperature coefficient of resonant frequency(${\tau}_{f}$) showed to increase, while the quality factor($Qxf_{0}$) did not show an apparent change. The composition of $0.7xZnWO_{4}-0.3TiO_{2}$ ceramics sintered at $900^{\circ}C$ with 5 wt% ZBS glass demonstrated 21.6 in dielectric constant(${\varepsilon}_{r}$), 14,800 in quality factor($Qxf_{0}$), and $+5\;ppm/^{\circ}C$ in temperature coefficient of resonant frequency(${\tau}_{f}$).

CaO첨가$(Ba, Pb)O-Nd_2O_3-TiO_2$ 세라믹스의 고주파 유전특성

윤상옥,최환,김경용,Yoon, Sang-Ok,Choi, Whan,Kim, Kyung-Yong 한국세라믹학회 1993 한국세라믹학회지 Vol.30 No.2

Effects of CaO on microwave dielectric properties of (Ba, Pb)O-Nd2O3-TiO2 ceramic ystem were investigated. As the content of CaO increases, the sintered bulk density decreases due to the decrease of sinterability. However, with increasing the sintering tmperature, the relative dielectric constants increases. This has been attributed on the formation of the 2nd phase inclusion, TiO2(rutile). The Q values increase due to the compensation effect of Ca ions up to 1 wt%, and then decrease due to the interfacial relaxation effects. The temperature coefficient of resonance frequency increases to a positive direction with increasing the amounts of CaO.

Zn_2-2xSi_1+xO₄ 세라믹스의 소결 및 마이크로파 유전 특성

윤상옥,김윤한,김소정,조소라,김신,Yoon, Sang-Ok,Kim, Yun-Han,Kim, So-Jung,Jo, So-Ra,Kim, Shin 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.7

Sintering and microwave dielectric properties of $Zn_{2-2x}Si_{1+x}O_4$ (x=0~0.10) ceramics were investigated. The secondary phase of ZnO was observed in the specimen for x=0 whereas $SiO_2$ was detected in that for x=0.05. The composition of $Zn_2SiO_4$ might be close to x=0.02, i.e., $Zn_{1.96}Si_{1.02}O_4$; the ratio of Zn/Si is 1.922. The insufficient grain growth was observed in the specimen of x=0. For the specimens of $x{\geq}0.05$, the grain growth sufficiently occurred through the liquid phase sintering. The value of quality factor of all specimens was dependent on the x value, i.e., the ratio of Zn/Si, whereas that of dielectric constant was independent. Relative density, dielectric constant, and quality factor ($Q{\times}f$) of the specimen for x=0.05, i.e., $Zn_{1.9}Si_{1.05}O_4$, sintered at $1,400^{\circ}C$ were 96.5%, 6.43, and 115,166 GHz, respectively.

(Ba_1-2xNa_2x)(Mg_0.5-xZr_xW_0.5)O₃ 세라믹스의 마이크로파 유전특성

윤상옥,홍창배,이윤중,김신,Yoon, Sang-Ok,Hong, Chang-Bae,Lee, Yun-Joong,Kim, Shin 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.6

We investigated the phase evolution, microstructure, and microwave dielectric properties of Na- and Zr-doped $Ba(Mg_{0.5}W_{0.5})O_3$ [i.e., ($Ba_{1-2x}Na_{2x})(Mg_{0.5-x}Zr_xW_{0.5})O_3$] ceramics. $BaWO_4$ as a secondary phase was observed in all compositions, and it increased as the dopant concentration increased. All specimens revealed a dense microstructure. For the composition of x=0.01, polyhedral grains were observed. As the dopant concentration increased, the densification and the grain growth were promoted by a liquid phase. The quality factor($Q{\times}f_0$) decreased remarkably, whereas the dielectric constant (${\varepsilon}_r$) tended to decrease as the dopant concentration increased. The dielectric constant, quality factor, and temperature coefficient of the resonant frequency of the composition of x=0.01 sintered at $1,700^{\circ}C$ for 1 h were 18.6, 216,275 GHz, and $-22.0ppm/^{\circ}C$, respectively.

기존 전력량계를 ICT 기반 지능형 AMI 센싱 장치로 변환 연구

윤상옥(Sang-Ok Yoon) 한국전자통신학회 2023 한국전자통신학회 논문지 Vol.18 No.1

자동전력량 측정이 가능한 AMI(: Advanced Metering Infrastructure)의 설치 비율은 전국적으로 43% 미만이고 특히 지역 기준인 경우에는 10.5%로 매우 열악한 상태이다. 따라서 스마트그리드를 위해서는 전력량계의 자동 정보 기록이 필요하므로 이를 위해서 기존 전력계량계를 개선하여 원격검침 및 사용 제어가 가능한 시스템 개발이 필요하다. 본 논문에서는 기존 전력량계를 AMI기능이 가능하게 하려면 IoT 및 AI를 이용하여 스마트 그리드 핵심인 AMI를 위한 기존 전력 계량기의 원격검침 및 제어 기술 개발을 수행하였다. 주요 연구 내용은 SG를 위한 전력계량기 감지 장치로 변환하기 위하여 Tensorflow와 Open-cv를 이용하여 숫자를 인식하였고, SG를 위한 전력계량기 원격검침 기능 테스트를 위해서는 Intel-Edson 하드웨어와 연동하여 장치를 구성하여 성능을 확인하였다. The installation rate of AMI(: Advanced Metering Infrastructure) capable of automatic electricity measurement is less than 43% nationwide and 10.5% in rural areas, which is very poor. Therefore, for the smart grid, automatic information recording of the watt-hour meter is required. For this purpose, it is necessary to develop a system capable of remote meter reading and use control by improving the existing watt-hour meter. In this paper, in order to enable the AMI function of the existing electricity meter, the remote meter reading and control technology of the existing electricity meter for AMI, the core of the smart grid, was developed using IoT and AI. The main research content was to recognize numbers using Tensorflow and Open-cv to convert it into a power meter sensing device for SG. We confirmed and checked the performance using the protyope system.

우리나라 창작동화와 외국 창작동화에 나타나는 부모양육행동

윤상옥(Sang Ok Yoon),송승민(Seung Min Song) 한국어린이문학교육학회 2007 어린이문학교육연구 Vol.8 No.1

본 연구는 우리나라의 창작동화와 외국의 창작동화에 나타난 부모의 양육태도의 차이를 비교 분석하였다. 분석대상은 현대가족의 부모 양육태도가 담겨있는 한국 창작동화 53편, 외국 창작동화 52편, 총 105편이었다. 본 연구에 나타난 결과를 요약하면 다음과 같다. 첫째, 우리나라 창작동화에 나타난 아버지의 양육행동의 일반적 특징은 애정·합리적 양육행동이 가장 높게 나타났고 강압적, 개방적 의사소통, 허용, 방임적 양육행동 순으로 나타났고 공격적 행동에 대한 보상 양육 행동은 나타나지 않았다. 외국 창작동화에 나타난 아버지의 양육행동의 일반적 특징은 애정·합리적 양육행동이 가장 높게 나타났고 공격적 행동에 대한 보상의 양육행동은 우리나라 창작동화와 같이 최하위로 나타났다. 둘째, 한국창작동화에 나타난 어머니의 양육행동은 애정 양육행동이 가장 많이 표현되고 있다. 그 다음으로 권위적 통제 양육행동과 적극적 참여 양육행동이 나타났고 그 뒤를 이어 합리적 지도, 과보호, 일관성 있는 규제, 성취 순으로 양육행동이 나타났으며 집단에 따라 유의할 만한 차이는 없는 것으로 나타났다. 외국 창작동화에서는 애정, 권위적 통제 양육행동이 집단에 따라 유의한 차이가 없었고 적극적 참여, 합리적지도, 일관성 있는 규제 순으로 양육 행동이 나타났다. 과보호와 성취에 대한 양육행동은 최하위로 사례수가 나타나지 않았다. The purpose of this study was to compare the parental behaviors in Korean children`s literature with foreign children`s literature. The subjects of the study are 53 widely read Korean children`s literature and 52 also widely read foreign children`s literature. The conclusions of the study are as follows: First, the most prominent characteristics of fathers` parenting behavior in the Korean children`s literature is the affection-rational parenting behavior in comparison with others. In the foreign children`s literature, the affection-rational parenting behavior was also the most frequently shown in fathers` parenting behaviors. Second, affective parenting behaviors were mostly frequent in mothers` parenting behaviors in the Korean children`s literature. Meanwhile, the authority-control parenting behaviors were shown almost as much as affective parenting behaviors of mothers in the foreign children`s literature.

TDMA 기반 무선 IP 영상 전송 시스템 설계 및 구현

윤상옥(Sang-Ok Yoon),석경휴(Gyeong-Hyu Seok) 한국전자통신학회 2022 한국전자통신학회 논문지 Vol.17 No.6

본 논문에서는 기존 유선기반 CCTV 감시시스템과 IP 카메라 시스템에서 발생되는 구축비용에 대한 부담을 절감하고자 무선통신기술을 활용한 TDMA기반 PoE 무선 다중 IP 카메라 전송시스템 개발이며, 국산 무선통신기술을 활용한 고화질 영상의 원거리 무선 전송 기술에 대해 설계 및 구현 하고자 한다. 제안 관련 기술에 대한 선 IP 전송 시스템의 송수신 프로토타입과 무선 다중 IP 카메라 전송 단말장치 및 영상 수집 장치(SB-200)에 대해 기술하였다. In this paper, the TDMA-based PoE wireless multi-IP camera transmission system using wireless communication technology is developed to reduce the burden of construction costs caused by the existing wired-based CCTV surveillance system and IP camera system. It intends to design and implement the long-distance wireless transmission technology of video. The transmission/reception prototype of the line IP transmission system and the wireless multi-IP camera transmission terminal and image acquisition device (SB-200) for the proposed related technology were described.