• Title/Summary/Keyword: NewWave

Search Result 2,162, Processing Time 0.041 seconds

Manufacture of an Acousto-Optical Spectrometer for Radio Astronomical Observations (우주전파관측용 음향광학 전파분광기의 제작)

  • 임인성;최재현;오승엽
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.8 no.1
    • /
    • pp.1-12
    • /
    • 1997
  • The acousto-optical spectrometer as a new type backend of the receiver system for radio astronomical observations is manufactured for radio signal analysis. We studied on the effect of Acousto-Optic and Acousto-Optic devices and designed the optics system. We manufactured the optical mount and the CCD detector for deflected beam and interface card. This acousto-optical spectrometer consisted of a laser, optics, acousto-optic deflector, CCD detector and Interface card. This system use He-Ne laser as a light source and use optics to get parallel beam and to focus the deflected beam. Acousto-optic deflector converts IF signal to ultrasonic wave and deflect the laser beam according to the Bragg deflection. The ultra wide band acousto-optic deflector has 1 GHz bandwidth and a total of 2,048 channel Charge Coupled Device for signal detection. In this study, we discuss the theoretical description on the effect of Acousto-optics, the design of the optics, manufacture of optical mount, CCD detector, interface card and we presented the results of experiment. As a result of measurement, we have 1,000 channels bandwidth from CCD channels.

  • PDF

Dual-Band Unequal Power-Divider Miniaturized by Metamaterial CRLH Phase-Shift Lines (메타 재질 구조 CRLH 전송선 기반 소형 이중 대역 비균등 전력분배기)

  • Eom, Da-Jeong;Kahng, Sung-Tek
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.23 no.9
    • /
    • pp.1048-1057
    • /
    • 2012
  • In this paper, a new compact dual-band unequal power divider is suggested. Instead of the quarter wavelength transmission line(TX-line)s for the branches of the conventional Wilkinson's power divider, we use composite right- and left-handed(CRLH) phase-shift lines and can reduce the physical length. With the non-linear dispersion of the meta-meterial, each branch in the proposed divider is designed to have $+90^{\circ}$ and $-90^{\circ}$ at $f_1$ and $f_2$ respectively. To validate the proposed method, the performances of the circuit and full-wave simulation results are shown with the CRLH dispersion curve. The measurement results are compared with the simulation results. Also, the size reduction effect by the proposed scheme is addressed.

Evaluation of DNA Damage Using Microwave Dielectric Absorption Spectroscopy

  • Hirayama, Makoto;Matuo, Youichirou;Sunagawa, Takeyoshi;Izumi, Yoshinobu
    • Journal of Radiation Protection and Research
    • /
    • v.41 no.4
    • /
    • pp.339-343
    • /
    • 2016
  • Background: Evaluation of deoxyribonucleic acid (DNA)-strand break is important to elucidate the biological effect of ionizing radiations. The conventional methods for DNA-strand break evaluation have been achieved by Agarose gel electrophoresis and others using an electrical property of DNAs. Such kinds of DNA-strand break evaluation systems can estimate DNA-strand break, according to a molecular weight of DNAs. However, the conventional method needs pretreatment of the sample and a relatively long period for analysis. They do not have enough sensitivity to detect the strand break products in the low-dose region. Materials and Methods: The sample is water, methanol and plasmid DNA solution. The plasmid DNA pUC118 was multiplied by using Escherichia coli JM109 competent cells. The resonance frequency and Q-value were measured by means of microwave dielectric absorption spectroscopy. When a sample is located at a center of the electric field, resonance curve of the frequency that existed as a standing wave is disturbed. As a result, the perturbation effect to perform a resonance with different frequency is adopted. Results and Discussion: The resonance frequency shifted to higher frequency with an increase in a concentration of methanol as the model of the biological material, and the Q-value decreased. The absorption peak in microwave power spectrum of the double-strand break plasmid DNA shifted from the non-damaged plasmid DNA. Moreover, the sharpness of absorption peak changed resulting in change in Q-value. We confirmed that a resonance frequency shifted to higher frequency with an increase in concentration of the plasmid DNA. Conclusion: We developed a new technique for an evaluation of DNA damage. In this paper, we report the evaluation method of DNA damage using microwave dielectric absorption spectroscopy.

A Case Study on the High-quality DCM applied to the Foundation of Breakwater (방파제 기초에 적용된 고품질 DCM공법의 설계 및 시공 사례)

  • Kang, Yeoun-Ike;Shim, Min-Bo;Shim, Sung-Hyun;Kim, Ha-Young;Shim, Jae-Bum;Chun, Youn-Chul;Yoon, Jung-Ik
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.09a
    • /
    • pp.815-826
    • /
    • 2009
  • The paper presents a case study addressing the design and construction aspects for DCM(Deep Cement Mixing) method employed as the foundation of a caisson type breakwater with heavy weight(10,700 ton/EA) and a high design wave height($H_{1/3}$=8.7m). The DCM was designed for the project(Ulsan New Port North Breakwater Phase 1) by optimizing the pattern of DCM columns with a combination of short and long columns (i.e., block type(upper 3m)+wall type(lower)) and considering overlapped section between columns as a critical section against shear force where the coefficient of effective width of treated column($\alpha$) was estimated with caution. It was shown that the value can be 0.9 under the condition with the overlapped width of 30cm. In addition to that, a field trial test was performed after improving conventional DCM equipment (e.g., mixing blades, cement paste supplying pipes, multi auger motor, etc.) to establish a standardized DCM construction cycle (withdrawal rate of mixing blades) which can provide the prescribed strength. The result of the field strength test for cored DCM specimens shows that the averaged strength is larger than the target strength and the distribution of the strength(with a defect rate of 7%) also satisfies with the quality control normal distribution curve which allows defect rate of 15.9%.

  • PDF

Minimization of a CW CO2 Laser Output Ripple by using High Frequency Resonance Phenomena (고주파 공진현상을 이용한 CW CO2 레이저의 출력리플 최소화)

  • Sikander, Sakura;Kwon, Min-Jae;Kim, Hee-Je;Lee, Dong-Gil;Xu, Guo-Cheng
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.62 no.6
    • /
    • pp.798-802
    • /
    • 2013
  • In a conventional DC power supply used for CO2 laser, the circuit elements such as a rectifier bridge, a current-limiting resistor, a high voltage switch, energy storage capacitors ans a high-voltage isolation transformer using high turn ratio are necessary. Consequently, those supplies are expensive and require a large space. Thus, laser resonator and power supply should be optimally designed. In this paper, we propose a new power supply using high frequency resonance phenomena for CW(Continuous wave) CO2 laser (maximum output of 23W with discharge length of 450mm). It consists of a transformer including leakage inductance, magnetizing inductance and half-bridge converter, a three-stage Cockcroft-Walton and PFC(Power factor correction) circuit. The output ripple voltage can be controlled the minimum of 0.24% under the high frequency switching of 231kHz. Furthermore, the output efficiency was improved to 16.4% and the laser output stability of about 5.6% was obtained in this laser system.

Design of digital clock level translator with 50% duty ratio from small sinusoidal input (작은 정현파입력의 50% Duty Ratio 디지털 클럭레벨 변환기 설계)

  • Park, Mun-Yang;Lee, Jong-Ryul;Kim, Ook;Song, Won-Chul;Kim, Kyung-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.23 no.8
    • /
    • pp.2064-2071
    • /
    • 1998
  • A new digital clock level translator has been designed in order to produce a clock source of the internal logic circuits. The translator output has 50% duty ratio from small sinusoidal input such as TCXO which oscillates itself in poratable components. The circuit consists of positive and negative comparators, RS latch, charge pump, and reference vol- tage generator. It detects pulse width of the output waveform and feedbacks the control signal to the input com-parator. It detects pulse width of the output waveform and feedbacks the control signal to the input com-parator reference, producing output waveform with valid 50% duty ratio of the digital signal level. The designed level translator can be used as a sampling clock source of ADC, PLL and the colck source of the clock synthesizer. The circuit wasdesigned in a 0.8.mu.m analog CMOS technology with double metal, double poly, and BSIM3 circuit simulation model. From our experimental results, a stable operating characteristics of 50 +3% duty ratio was obtained from the sinusoidal input wave of 370 mV.

  • PDF

Reduction of combustion instability using flame holder integrated injector (통합형 연료분사장치를 통한 연소불안정 저감)

  • Hwang, Yong-Seok;Lee, Jong-Guen;Park, Ik-Soo;Choi, Ho-Jin;Jin, Yu-In;Yoon, Hyun-Gull;Lim, Jin-Shik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.11a
    • /
    • pp.432-437
    • /
    • 2010
  • A new device injecting secondary fuel behind flameholder was invented and tested in order to reduce low frequency combustion instability of combustor using V-gutter flameholder. Specially designed combustion device could make large combustion instability up to 180 dB successfully, and newly invented device made a success to reduce 110~120Hz low frequency pressure pulsation up to 84%. It was found that the fuel flow rate of secondary fuel supplying behind flameholder was the only parameter which dominates reduction of instability. It is considered that stabilized flame with sufficient secondary fuel can lead to break the connection between combustion system and acoustic system due to independence of flame from fluctuation of main fuel resulted from synchronization with acoustic wave.

  • PDF

Infinite Element for the Analysis of Harbor Resonances (항만 부진동 해석을 위한 무한요소)

  • Park, Woo-Sun;Chun, In-Sik;Jeong, Weon-Mu
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.6 no.2
    • /
    • pp.139-149
    • /
    • 1994
  • In this paper, a finite element technique is applied to the prediction of the wave resonance phenomena in harbors. The mild-slope equation is used with a partial reflection boundary condition introduced to model the energy dissipating effects on the solid boundary. For an efficient modeling of the radiation condition at infinity, a new infinite element is developed. The shape function of the infinite element is derived from the asymptotic behavior of the first kind of the Hankel's function in the analytical boundary series solutions. For the computational efficiency, the system matrices of the element are constructed by performing the relevant integrations in the infinite direction analytically. Comparisons with the results from experiments and other solution methods show that the present model gives fairly good results. Numerical experiments are also carried out to determine the proper distance to the infinite elements from the mouth of the halter, which directly affect the accuracy and efficiency of the solution.

  • PDF

Development of a High Speed, Coastal Passenger SWATH Ship with Good Speed Performance and Seakeeping Quality (내항성능과 속도성능이 우수한 고속 연안여객 소수선면 쌍동선형 개발)

  • H.H. Chun;M.S. Kim;Y.R. Joo;G.H. Lee;M.H. Lee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.35 no.4
    • /
    • pp.87-97
    • /
    • 1998
  • One of good ways to make a ship perform well in rough seas is to reduce its waterplane area and accordingly is subject to a reduced wave exciting forties. However, a great reduction of the waterplane area may create a penalty in speed performance due to the increased ratio of the wetted area to the displacement volume. This paper suggests a new catamaran hull form which compromises the speed and seakeeping quality by increasing the waterplane area somehow compared with that of the conventional SWATH ship. A 350 passenger carrying SWATH ship with a cruising speed of 30 knots in sea state of 4 has been developed and its performance was validated by the model tests. The design concept resistance performance and seakeeping dualities of the design craft are presented together with its comparative performance comparison with other high speed crafts.

  • PDF

The Protection Potential Decision by Electrochemical Experiment of Al-Mg-Si Alloy for Ship in Seawater (해수용액에서 선박용 Al-Mg-Si 합금의 전기화학적 실험에 의한 방식전위 결정)

  • Jeong, S.O.;Park, J.C.;Han, M.S.;Kim, S.J.
    • Corrosion Science and Technology
    • /
    • v.9 no.1
    • /
    • pp.48-55
    • /
    • 2010
  • The many vessels are built with FRP(Fiber-Reinforced Plastic) material for small boats and medium vessels. However, FRP is impossible to be used for recyclable material owing to environmental problems and causes large proportion of collision accidents because radar reflection wave is so weak that large vessels could not detect FRP ships during the sailing. Hence, Al alloy comes into the spotlight to solve these kinds of problems as a new-material for next generation instead of FRP. Al alloy ships are getting widely introduced for fish and leisure boats to save fuel consumption due to lightweight. In this study, it was selected 6061-T6 Al alloy which are mainly used for Al-ships and carried out various electrochemical experiment such as potential, anodic/cathodic polarization, Tafel analysis, potentiostatic experiment and surface morphologies observation after potentiostatic experiment for 1200 sec by using the SEM equipment to evaluate optimum corrosion protection potential in sea water. It is concluded that the optimum corrosion protection potential range is -1.4 V ~ -0.7 V(Ag/AgCl) for 6061-T6 Al alloy, in the case of application of ICCP(Impressed current cathodic protection), which was shown the lowest current density at the electrochemical experiment and good specimen surface morphologies after potentiostatic experiment for Al-Mg-Si(6061-T6) Al alloy in seawater environment.