• The Journal of Information Technology
• /
• v.3 no.3
• /
• pp.57-65
• /
• 2000

We have proposed BIST method and circuit for embedded 16M SDRAM with logic. It can test the AC parameter of embedded 16M SDRAM using the BIST circuit capable of detecting the address of a fail cell of a 16M SDRAM installed in an Merged Memory with Logic(MML) generating the information of repair for redundancy circuit. The function and AC parameter of the embedded memory can also be tested using the proposed BIST method. The total gate of the BIST circuit is approximately 4,500 in the case of synthesizing by $0.25\mu\textrm{m}$ cell library. and verify the result of Verilog simulation. The test time of each one AC parameter is about 200ms using 2Y-March 14N algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.11 no.3
• /
• pp.445-453
• /
• 2000

In this paper, the method of designing an active inductor for MMIC is proposed. The proposed tunable active inductor is composed of a cascade FET with feedback capacitors and resistors. Because of a very low series resistance in the proposed inductor, a very high Q factor can be obtained. Also it has an excellent characteristics suitable for high frequency band. The inductance value can be changed by controlling feedback capacitors, resistors and a bias voltage respectively. When the feedback resistor and parallel resistor within circuits are varied, the inductance value is changed from 0.2 nH to 1.7 nH in the range 1 to 15 GHz. Also we designed bandpass filter using the proposed active inductor and it shows the insertion loss of 0.4 dB and return loss, 20 dB.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.6
• /
• pp.816-826
• /
• 2015

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from $10^7$ to $10^{10}cfu/g$ during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to $10^9cfu/g$ DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

• Korean Journal of Pharmacognosy
• /
• v.47 no.1
• /
• pp.79-83
• /
• 2016

This study developed an HPLC analysis method for the determination of isoegomaketone (IK) and perillaketone (PK) in Perilla frutescens (L.) Britton leaves. P. frutescens ethanol extract was optimized through an HPLC analysis using a C18 column ($250{\times}4.6mml$, D, $S-5{\mu}m$, 12 nm) with gradient elution of water and acetonitrile as the mobile phase at a flow rate of 1 mL/min and a UV detection wavelength of 254 nm. The results of this method showed linearity in the calibration curve at a coefficient of correlation ($R^2$) of IK 0.9995, PK 0.9998. The limits of detection (LOD) for IK and PK were $0.234{\mu}g/mL$ and $0.952{\mu}g/mL$. The limits of quantification (LOQ) for IK and PK were $0.017{\mu}g/mL$ and $0.043{\mu}g/mL$. The inter-day precision RSDs of IK and PK in the P. frutescens were 1.25 to 2.69% and 0.36 to 1.10%, respectively, and the intra-day precision RSDs of IK and PK were 0.96 to 2.51% and 0.90 to 1.93%, respectively. The accuracies of IK and PK were 96.31 to 97.92% and 101.26 to 105.14%. In conclusion, this method was applied successfully to the detection of IK and PK in P. frutescens.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.165-165
• /
• 2007

투명전도박막은 ITO, $SnO_2$, ZnO, 등이 있으나 $SnO_2$는 자외선 영역까지 투과시키는 우수한 광학적 특성을 나타내지만, 상당히 큰 전기저항으로 인해 현재는 현재 ITO가 널리 이용되고 있다. ITO(Indium Tin Oxide)박막은 자외선 영역에서 반사율이 높으며 가시광선영역에서는 80%이상의 뛰어난 투과율을 가지고 있다. 또한 낮은 전기저항과 넓은 광학적 밴드갭 때문에 가장 유용한 투과전도성 재료 중에 하나이다. 이러한 특성 때문에 여러 가지 문자 표시소자의 투명전극, 태양전지의 창재료, 정전차폐를 위한 반도체 포장재료, 열반사막, 면발열체, 광전변환 소자에 응용되고 있다. 일반적으로 박막의 제작에는 저항가열법과 전자선가열법, 스퍼터링법의 물리적 증착과 화학적 증착으로 나뉜다. 본 논문에서는 증착온도를 달리 하여 RF-sputtering에 의해 ITO박막을 증착한 후 온도증가에 따른 박막의 특성을 연구하였으며 또한 광역평탄화를 위한 CMP공정을 적용하여 증착온도가 연마에 미치는 영향을 연구하였다. 본 실험에서 사용된 ITO박막은 $2{\times}2Cm$의 Corning glass위에 증착되었으며 타겟은 $In_2O_3$와 $SnO_2$가 9:1로 혼합된 Purity 99.99%이상의 직경 2 inch인 ITO타겟을 사용하였다. 박막 증착시 기판온도는 상온에M $200^{\circ}C$까지 변화시켰으며 RF power는 100W로 일정하게 하였으며 증착압력은 $8{\times}10^{-2}$Torr이였다. CMP공정조건은 헤드속도 60rpm, 플레이튼 속도 60rpm, 슬러리 주입 유량 60mml/min, 압력 $300g/cm^2$이였다. 전기적 특성은 four point probe를 이용하여 측정하였으며 광학적 특성은 UV-Visible Spectrometer를 이용하여 200~900nm의 파장범위에서 광투과도를 측정하였다.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.64-73
• /
• 2019

The manufacturing companies under Make-To-Order (MTO) production environment face highly variable requirements of the customers. It makes them difficult to establish preemptive production strategy through inventory management and demand forecasting. Therefore, the ability to establish an optimal production schedule that incorporates the various requirements of the customers is emphasized as the key success factor. In this study, we suggest a process of designing the simulation model for establishing production schedule and apply this model to the case of a flat glass processing company. The flat glass manufacturing industry is under MTO production environment. Academic research of flat glass industry is focused on minimizing the waste in the cutting process. In addition, in the practical view, the flat glass manufacturing companies tend to establish the production schedule based on the intuition of production manager and it results in failure of meeting the due date. Based on these findings, the case study aims to present the process of drawing up a production schedule through simulation modeling. The actual data of Korean flat glass processing company were used to make a monthly production schedule. To do this, five scenarios based on dispatching rules are considered and each scenario is evaluated by three key performance indicators for delivery compliance. We used B2MML (Business To Manufacturing Markup Language) schema for integrating manufacturing systems and simulations are carried out by using SIMIO simulation software. The results provide the basis for determining a suitable production schedule from the production manager's perspective.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.14 no.1
• /
• pp.22-29
• /
• 2000

This paper deals with the dielectric characteristics of $SF_6$ gas gap stressed by $\pm$1.2/44[$mutextrm{s}$] non-oscillating impulse and $\pm$0.4[$mutextrm{s}$]/1.14[MHz] oscillating impulse voltages in the presence of a needle-shape metallic particle in gas-insulated switchgear(GIS). Breakdown voltage-time (V-t) and breakdown voltage-gas pressure (V-p) characteristics were investigated and discussed. The experiments were carried out under highly inhomogeneous field geometry with a needle protrusion whose length and radius are 10[mm] and 0.5[mm], respectively. The gas pressure ranges from 0.1 to 0.5[㎫]. As a result, it was found that the electrical breakdown for both the positive and negative polarity develops with steplike pulses in leader mechanism, When subjected to the positive oscillating impulse voltage, the minimum breakdown voltages appeared in all the gas pressure ranges and the V-t curves have a pronounced upturning at short times to breakdown and give a little dependence of the gas pressure. On the other hand, in the case of the negative polarity the dependence of the V-t and V-p characteristics on the wave shape of the applied voltages is known to be appreciable.