• 제목/요약/키워드: Operational Stability

검색결과 342건 처리시간 0.029초

Advanced Retention and Drainage Technology Offers Improved Performance and Operational Cost Savings

  • Freeman William L.
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
    • /
    • pp.239-243
    • /
    • 2006
  • Papermaking has changed remarkably during the past 20 years, creating huge pressures on retention and drainage programs. During this time, technology has advanced from single PAM flocculants to inorganic microparticle-based programs and then to micropolymer-based programs. In today's evolving fine paper market, retention and drainage programs have to meet increased demands in many areas, such as increased speed, GAP formers, dilution headboxes, higher ash levels, reduced furnish quality, lower cost, and increased machine efficiency. Hercules recently introduced a new technology that offers performance and stability improvements and operational cost savings as compared to existing advanced technologies. $PerForm(R)$ SP Advanced Retention and Drainage Technology consists of a family of products based on a structured organic particulate that offers papermakers the ultimate flexibility for management of wet end chemistry. This paper compares $PerForm(R)$ SP Advanced Retention and Drainage Technology to inorganic microparticle and micropolymer technologies and provides multiple case histories on machines that demonstrate the benefits of the technology. In these case histories, the PerForm SP is shown to provide improved retention and drainage that results in improved performance and operational cost savings to the mill.

  • PDF

A 1.5 V High-Cain High-Frequency CMOS Complementary Operational Amplifier

  • Park, Kwangmin
    • Transactions on Electrical and Electronic Materials
    • /
    • 제2권4호
    • /
    • pp.1-6
    • /
    • 2001
  • In this paper, a 1.5 V high-gain high-frequency CMOS complementary operational amplifier is presented. The input stage of op-amp is designed for supporting the constant transconductance on the Input stage by consisting of the parallel-connected rail-to-rail complementary differential pairs. And consisting of the class-AB rail-to-rail output stage using the concept of elementary shunt stage and the grounded-gate cascode compensation technique for improving the low PSRR which was a disadvantage in the general CMOS complementary input stage, the load dependence of open loop gain and the stability of op- amp on the output load are improved, and the high-gain high-frequency operation can be achieved. The designed op-amp operates perfectly on the complementary mode with the 180° phase conversion for a 1.5 V supply voltage, and shows the DC open loop gain of 84 dB, the phase margin of 65°, and the unity gain frequency of 20 MHz. In addition, the amplifier shows the 0.1 % settling time of .179 ㎲ for the positive step and 0.154 ㎲ for the negative step on the 100 mV small-signal step, respectively, and shows the total power dissipation of 8.93 mW.

  • PDF

High Performance Tandem OLEDs for Large Area Full Color AM Displays and Lighting Applications

  • Hatwar, T.K.;Spindler, J.P.;Slyke, S.A. Van
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
    • /
    • pp.1577-1582
    • /
    • 2006
  • Tandem OLED structures formed by connecting two or more low-voltage electroluminescent units (stacks) are effective for achieving high efficiency at low current density as well as long operational lifetime. We have fabricated white emitting tandem structures with two or three low-voltage white-emitting stacks using transparent organic "PN"-type connectors. Three- stack white tandem structures with efficiency greater than 24 cd/A at D65 and operational stability of about 110,000 h. (extrapolated) at $1000\;cd/m^2$ have been demonstrated. With a stacked structure, the power consumption for displays using an RGBW format can be reduced by 25% compared to previously described formulations. We have also fabricated advanced white tandem structures where the color gamut (NTSC x,y ratio) has been improved to greater than 70% using standard color filters. The white OLEDs can also be used to increase the colorrendering index CRI (>80%), an important consideration for solid-state lighting.

  • PDF

BiCMOS 선형 OTA (A BiCMOS linear Operational Transconductance Amplifier)

  • 박지만;소재환;류남규;정원섭
    • 전자공학회논문지A
    • /
    • 제31A권12호
    • /
    • pp.135-141
    • /
    • 1994
  • A linear BiCMOS operational transconductance amplifier (OTA) is described. It consists of a CMOS linear transconductor and a bipolar translineear current gain cell followed by three CMOS current mirrors. The proposed circuit has comparable linearity and temperature stability but superior dc characteristics to its bipolar counterpart. A test circuit with a transconductance of 47.3$\mu$s has been simulated. Simulation results show that a linearity error of less than $\pm$1 percent over an input volgate range from -1.0 to 1.0 V and a output dc offset current as small as-3.6 nA can be obtained.

  • PDF

견관절 충돌증후군의 고찰 (Review of Shoulder Joint Impingement Syndrome)

  • 김인섭
    • 대한임상전기생리학회지
    • /
    • 제2권1호
    • /
    • pp.93-100
    • /
    • 2004
  • Shoulder impingement syndrome is cause by the collision of acromion, acrominoclaviclar joint, coracoacromino ligament, coracoid process and synovial sac, biceps brachiialis tendon, rotator cuff muscle. Treatment for Shoulder impingement syndrome is genetally classified into two different methods; preservative method and operational method. Operational method includes rotator cuff sutura, anterior acromioplasty, arthroscope decompression. Preservative method includes rest, medicinal therapy, physical therapy. Physical therapy concentrates on pain control, functional recovery and prevention of disease progress. It is also important for physical therapy to maintain the strength of rotator cuff. Strengthening rotator cuff decreases the collision and helps the stability of shoulder joint. In conclusion, it must be aware that shoulder impingement syndrome and some other shoulder problem demand different treatment, which results in a better outcome.

  • PDF

전력수급계획 및 운용해석 종합시스템 개발 (Development of the Integrated System for Power System Operational Planning an)

  • 박시우;윤용범;남재현;안양근
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 하계학술대회 논문집 C
    • /
    • pp.1042-1045
    • /
    • 1998
  • The main purpose of HITES(Highly Integrate Total Energy System) is to build and develop an integrated energy system for power system operational planning and analysis which consists of load forecast, economic generation schedule, stability analysis and relational database system. The integrated energy system can be utilized to supply a stable electric power and operate KEPCO power system facilities economically. This system will be put into operation in 1999. This paper describes the main feature of the HITES, system main functions, numerical methods adopted this system, and network configuration.

  • PDF

주파수-아날로그 전압 변환 회로의 설계 (Design of Frequency to Analog-Voltage Converter)

  • 최진호
    • 한국정보통신학회논문지
    • /
    • 제15권5호
    • /
    • pp.1119-1124
    • /
    • 2011
  • 전류 컨베이어 회로의 동작은 연산증폭기와 유사하며, 우수한 선형성과 안정성을 가지고 있다. 이 논문에서는 전류 컨베이어 회로를 이용하여 주파수 신호를 아날로그 전압 신호로 변환하는 회로를 설계하였다. 회로는 공급전압 5volts에서 동작하도록 설계하였으며, HSPICE 시뮬레이션을 통하여 결과를 분석하였다. 회로의 동작 범위는 4kHz 이상 200kHz 이하의 주파수에서 출력 전압의 에러는 +2.5% ~ -1.3% 이내 이었다.

UGV의 운용적합성 평가를 위한 운용 시험 시나리오 연구 (Study on the Operational Test Scenarios for Assessment of Unmanned Ground Vehicle's Operation Suitability)

  • 강규민;이경수
    • 자동차안전학회지
    • /
    • 제15권4호
    • /
    • pp.6-15
    • /
    • 2023
  • This paper develops scenarios to evaluate the safety performance of Unmanned Ground Vehicle on military circumstances. The scenarios were created using Pegasus Project 6-layer format. These scenarios consist of straight road, curved road, merging road and crossroad. We adapt these scenarios to unpaved road. The characteristics of unpaved roads were divided into roughness, friction coefficient and road frequency. This adaption is validated via computer simulation. We observe the scan lines of vehicle become tangled of the straight road that make the cognitive abilities of the vehicle low and the lane-keeping is unable when vehicles entering curved off-roads over 40 km/h. The developed scenarios will contribute to enhancing stability from the perspective of introducing autonomous driving technology to Korean military.

라디오존데 고층관측자료를 활용한 한반도 남해안 지역의 2019년도 여름철 대기 안정도 특성 분석 (Analyzing the Characteristics of Atmospheric Stability from Radiosonde Observations in the Southern Coastal Region of the Korean Peninsula during the Summer of 2019)

  • 신승숙;황성은;이영태;김병택;김기훈
    • 한국지구과학회지
    • /
    • 제42권5호
    • /
    • pp.496-503
    • /
    • 2021
  • 한반도 남해안 지역의 여름철 대기 안정도 특성을 분석함으로써, 한반도 특성에 맞는 강수 예측을 위한 대기 안정도 지수의 정량적인 임계값을 도출하고자 하였다. 보성 표준기상관측소에서 관측한 2019년도 여름철 라디오존데 집중관측자료를 분석에 사용하였으며, 총 관측자료는 243개 이다. 강수 유무 및 중규모 대기 현상에 대한 대기 안정도를 분석하기 위해서, 대류가용잠재에너지(Convective Available Potential Energy, CAPE)와 폭풍지수(Storm Relative Helicity, SRH)를 비교하였으며 특히 SRH 분석은 고도 별로 총 4개의 층으로(0-1, 0-3, 0-6, 0-10 km) 세분화하였다. 강수 유무에 따른 분석은 강수가 없는 경우, 강수발생 전 12시간, 강수 발생 시로 구분하여 수행하였다. 그 결과, 2019년도 보성에서 발생한 여름철 강수 예측에는 CAPE 보다 SRH가 더 적합하며 0-6 km SRH가 약한 토네이도가 발생가능한 기준과 같은 150 m2 s-2 이상일 경우 강수가 발생한 것으로 분석 된다. 또한, 장마와 태풍 기간의 대기 안정도를 분석한 결과를 보면, 일반적으로 SRH는 대기 깊이가 두꺼워 질수록 값이 커지는 데 반해서 0-10 km SRH 평균값 보다 0-6 km 의 SRH 값이 더 크게 나타났다. 따라서, 2019년도 보성에서 발생한 태풍에 의한 강수를 판별하는 데는 0-6 km 의 SRH 값이 더 효과적이라고 할 수 있다.

로켓 연소기의 동압 진폭엔벨롭을 이용한 안정성 해석 (Stability Analysis Using the Amplitude Envelope of Dynamic Pressure in the Rocket Combustor)

  • 이수용
    • 한국추진공학회지
    • /
    • 제25권1호
    • /
    • pp.42-49
    • /
    • 2021
  • 얼마나 쉽게 연소불안정 해지는지에 대한 척도로서, 작동 안정성 여유를 예측하기 위해 로켓연소기시스템의 열음향 불안정을 검토하였다. 연소기 시스템의 동적거동 특성파악을 위해 연소성능시험 중 측정한 연소기의 동압 데이터를 바탕으로 시간이 지남에 따라 시스템이 안정해지는지를 결정하는 파라미터로서 성장속도 계수를 구하였다. 파라미터 추출은 시계열 압력데이터를 주파수 도메인으로 전환하여 관심모드의 성장속도나 감쇠계수를 도출하는 방법을 우선 검토하였으며, 스토캐스틱 해석의 경우에는 압력진동의 진폭 엔벨롭으로 부터 압력진폭 PDF를 추출했다.