• 동력기계공학회지
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• 제4권3호
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• pp.48-54
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• 2000

This paper describes the effect of molding pressure, specimen geometries for Mixed Mode I/II interlaminar fracture toughness of carbon fiber reinforced plastic composites by using asymmetrical double cantilever beam(ADCB) specimen. The value of $G_{I/IIC}$ as a function of various molding pressure is almost same at 307, 431, 585 kPa. However it shows the highest value under 307 kPa molding pressure. The effect of $G_{I/IIC}$ due to the change of initial crack length of ADCB specimen was almost negligible in this study. It turns out that the condition for mix mode quasi-static crack growth in ADCB specimen is the ratio of the crack length to that of the specimen, i.e., ${\alpha}/L<0.4$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.719-723
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• 2002

The purpose of this study is to suggest the correlation of single-number ratings for sound insulation by floor impact. As a assessment method of impact sound insulation. we selected the IIC contour of ISO, A weighted sound level. Inverse A-weighting curve and L-Index of japanese industrial standard. And we estimated the single-number ratings by application the measured data of impact sound level to each method. The results showed that the coefficients of determination between each two single-number ratings were very high (more than 0.9169). And In the condition of same assessment method, the coefficient of determination for light-weight impact sound was higher than that for heavy-weight impact sound.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.958-961
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• 2010

We can monitor home from any remote location using our existing telephone line. We have already some technologies to perform these types of application such as: Bluetooth, IR. But these are used in a limited area which we can easily come over in our system. Our propose system has two sections one is Remote Section (RS) where the client will place the request and another is Local Section (LS) where the telephone line is connected with an Input Interfacing Circuit (IIC). Input Interfacing Circuit (IIC) receives the frequency and converts frequency to machine language. Output Interfacing Circuit (OIC) sends voice signal to the client as acknowledgement through modem then the client proceeds for the next steps. This system can be used in commercial or industrial purposes such as controlling computer from remote locations, home monitoring system instead of man or any kind of switching.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권1호
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• pp.21-25
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• 2004

From the gradual increasing state of charge (GISOC) observations, electrochemical behavior of multi-walled carbon nanotube│(lM LiP $F_{6}$ , EC,DEC,DME 3:5:5 volume ratio)│lithium cells was evaluated using the galvanostatic charge-discharge process. A MWCNT delivers a specific charge capacity of 1,300 mAh/g in a Li cell when cycled up to an end voltage of 0 V (vs. Li/L $i^{＋}$ )at a constant current rate every 10 hours. However, in the present study, the specific discharge capacity obtained is 338 mAh/g, thus amounting to a coulombic efficiency of only 26％. Further, when the MWCNT│Li cells were tested using the GISOC method, two distinguishable linear-fit ranges were observed due to the intercalation/deintercalation of lithium, which were found to have II $E_1$, IIC $s_1$ and II $E_2$of 27.3％, 372 mAh/g, and 25.5％, respectively. Q $c_1$, could be calculated from the data of IIE and IICs of each range by the modified equation "II $C_{sum}$= $\Sigma$( $Q_{C}$- $Q_{D}$)=(II $E_{1}$$^{-1}$ ) $Q_{Dl}$ ＋(II $E_2$$^{-1}$ -1) ( $Q_{D2}$- $Q_{Dl}$ ) ＋ IIC $s_1$= $Q_{Cl}$ - $Q_{Dl}$ ". Results of the GISOC method could be converted to the results of galvanostatic charge-discharge process, irrespective of the state of charge of the cell or battery.ery.y.y.

• 전기전자학회논문지
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• 제14권3호
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• pp.190-198
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• 2010

피에조소자를 구동하여 자동카메라의 초점을 자동으로 제어하는 시스템에서 피에조를 구동하는 집적회로를 설계하였다. 가공된 피에조에 변위를 만들기 위해서는 고전압 DC가 필요하다. 휴대형기기에서 사용하는 3[V]~4.2[V]정도의 낮은 전원전압을 약 80[V]로 승압하여 피에조 구동전압으로 제공하는 한편 입력되는 1[Vp-p]의 제어신호를 -20[V]에서 +80[V]까지 조절되도록 설계하였다. 또한 IC 외부에 적용되는 소자가 최소가 되도록 하여 시스템의 전체 크기를 줄일 수 있도록 하였다. 제어용 프로세서로 IIC(Inter-IC) 인터페이스를 적용하기 위하여 구동회로 내부에 IIC 인터페이스 디지털 로직을 내장하였는데, 이는 제품의 검증, 양산시 양품판정을 쉽게 해주는 장점이 있다. 제작공정은 AMIS 사의 I2T100 2P_3M 공정을 사용하였는데 0.6[um], 100[V]급 BCD공정이며, 6INCH 웨이퍼를 사용하였다. 전원전압 3.6[V], 소비전력은 약 40[mW]정도이다. 칩 사이즈는 1600*1500 [$um^2$]이며, 칩을 소형패키지에 내장하여 조립하였기 때문에 휴대형기기에 적용이 편리하게 되어있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.53-61
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• 2004

Characteristics of half cells of graphite/lithium and LiCoO$_2$/lithium, and full cells of graphite/LiCoO$_2$/ were analyzed by the use of GISOC(the gradual increasing of the state of charge). GISOC analyses generated IIE(the initial intercalation efficiency), which represents lithium intercalation property of the electrode material, and IIC$_{s}$(the initial irreversible capacity by the surface), which represents irreversible reaction between the electrode surface and electrolyte. Linear-fit range of graphite and LiCo/O$_2$electrodes were respectively 370 and 150 mAh/g based on material weight. IIE of graphite and LiCo/O$_2$electrodes were respectively 93∼94 % and 94∼95 %, and IICs of graphite and LiCo/O$_2$electrodes were 15∼17 mAH/g and 0.3∼1.7 mAh/g, respectively. IIE of graphite/LiCo/O$_2$full cell for GX25 and DJG311 as graphite showed 89∼90 %, which IIE value was lower than IIE of half cell of the cathode and the anode. Parameters of IIE and IIC$_{s}$ can also be used to represent not only half cell but also full cell. The characteristics of the full cell can be simulated through the correlative interpretation of potential profile, IIE, and IIC$_{s}$ of half cells.cells.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.80-83
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• 2005

In this work, effects of oxygen plasma on surface characteristics of carbon fibers were investigated in mechanical properties interfacial of carbon fibers-reinforced composites. The surface properties of the carbon fibers were determined by acid/base values, FT-IR, and X-ray photoelectron spectroscopy (XPS). Also, the mechanical properties of the composites were studied in and critical stress intensity factor ($K_{IC}$) and critical strain energy release rate mode II ($G_{IIC}$) measurements. As experimental results, the $O_{lS}/C_{lS}$ ratio of the carbon fiber surfaces treated by oxygen plasma was increased compared to that of untreated ones, possibly due to development of oxygen-containing functional groups. The mechanical properties of the composites, including $K_{IC}$ and $G_{IIC}$ had been improved in the oxygen plasma on fibers. These results could be explained that the oxygen plasma was resulted in the increase of the adhesion of between fibers and matrix in a composite system.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2000년도 춘계정기학술대회 e-Business를 위한 지능형 정보기술 / 한국지능정보시스템학회
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• pp.333-340
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• 2000

Research on group decisions and electronic meeting systems have been increasing rapidly according to the widespread of Internet technology. Although various issues have been raised in empirical research, we will try to solve an issue on idea categorizing in the group decision making process of electronic meeting systems. Idea categorizing used at existing group decision support systems was performed in a top-down procedure and mostly b participants; manual work. This resulted in tacking as long in idea categorizing as it does for idea generating clustering an idea in multiple categories, and identifying almost similar redundant categories. However such methods have critical limitation in the electronic meeting systems, we suggest an intelligent idea categorizing methodology which is a bottom-up approach. This method consists of steps to present idea using keywords, identifying keywords' affinity, computing similarity among ideas, and clustering ideas. This methodology allows participants to interact iteratively for clear manifestation of ambiguous ideas. We also developed a prototype system, IIC (intelligent idea categorizer) and evaluated its performance using the comparision experimetn with other systems. IIC is not a general purposed system, but it produces a good result in a given specific domain.

• 한국정보통신학회논문지
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• 제8권5호
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• pp.1129-1133
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• 2004

정보통신부에서는 우편, 보험, 금융, 전파 등에 관련된 온라인 업무를 처리하기 위해 약 3,010회선의 기반망을 운영하고 있으나 서비스 대역의 유연성 미흡으로 대역폭 낭비요인이 발생하고 있다. 따라서 본 연구에서는 정보통신부 기반망에 대한 경제성 및 효율성 등에 대한 비교ㆍ분석을 통해 제 3 단계 정보통신부 기반망 운영개선 방안을 수립하였다. 본 연구 결과를 토대로 정보통신부 기반망 운영정책을 추진할 경우 금융기관으로서의 이미지가 제고되고 차별화된 정부기관으로서의 신뢰성과 안전성을 바탕으로 수준 높은 서비스를 제공 할 수 있을 것으로 판단된다.

• 한국해양공학회지
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• 제10권4호
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• pp.75-83
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• 1996

Polymeric composites can be subjected to a wide variety of environmemtal conditions in practical use. One of most important conditions to be considered in the stuctural design using such materials is the miisture envirnment. Thus the moisture effect on interlaminar fracture toughness $G_IC$ and $G_IIC$ of CFRP(carbon fiber reinforced plastic) composed of carbon fibers and epoxy resin is studied in this paper. Specimens were first processed in 25, 50, $80^{\circ}C$ flesh water and $25^{\circ}C$ sea water for various periods of time. After that, the water absorption and fracture toughness tests were performed under laboratory atmosphere. As result, the specimen processed in $80^{\circ}C$ flesh water indicates the highest misture absorbing capability, the second in $50^{\circ}C$ flesh water, the third in $25^{\circ}C$ sea water, and the specimen in $25^{\circ}C$ flesh water does the lowest. The interlaminar fracture toughness $G_IC$ increases, approaches to the maximum, and decreases as the immersion time increases. In case of interlaminar $G_IIC$, the value of the specimen processed in $80^{\circ}C$ flesh water turns out to be higher than others. In addition, the scanning electron micrographs(SEM) of fracture surfaces were also examined in order to explain the mechanism of fracture.