• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.11
• /
• pp.69-76
• /
• 2010

From the present paper we researched about the design of 4-Way Wilkinson divider with waveguide to stripline transition which used to split the LO signal with equi-amplitude and equi-phase in the X-Band Monopulse radar RF front-end. The monopulse radar front end operating in the X-Band is composed of 3 waveguide reception mixers which down convert sum, azimuth and elevation signal to IF and one SSB waveguide mixers which generate X-Band test signal. It is required the 4-way divider with low loss, equi amplitude and equiphase splitting the LO signal to provide the LO signal to each mixer consisting RF frontend. In this paper we designed and fabricated the 4-Way Wilkinson divider with waveguide transition to divide the LO signal into equi-amplitude and equi-phase. The fabricated Wilkinson divider have the insertion loss 6.8dB, VSWR 1.06~1.28, and phase balance maximum 4.5degree for each output ports.

• Nuclear Engineering and Technology
• /
• v.22 no.2
• /
• pp.108-115
• /
• 1990

The measurements of X-ray production cross-sections for 0.5~1.2-MeV proton beam are carried out on Cu and Au. For this experiment, the proton tram generated from the SNU 1.5-MV Tandem Van do Graaff accelerator is Incident on the target. The X-rays and the backscattered protons from the irradiated target are detected simultaneously by the Si(Li) X-ray detector and the SSB (Silicone Surface Barrier) charged particle detector The measured values of X-ray production cross-sections are compared with other experimental values and theoretical values such as the PWBA (Plane Wave Born Approximation) and the ECPSSR(Perturbed Stationary State corrected Energy loss, Coulomb deflection, Relativistic effects) values. For measured cross-sections near 1.0- MeV proton energy, the ECPSSR (D.D. Cohenet al., 1985) shows better agreement than the PWBA. Particularly, that of Au for 1.2 MeV proton beam is 9.69$\pm$ 0.39 barns which deviates from the ECPSSR by less than 5%. and the experimental data for 0.5~1.2- MeV proton agree with most of other experimental values within 30%.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.2
• /
• pp.347-354
• /
• 1999

Generally, transceiver is operated to the remote control for the purpose of breading the traffic zone which is established on a mountain peak, island and building top using private line. Therefor, the remote control system of public radio station have been the very important role that is decision the quality relate to the quickness, accuracy, safety of communication on old type transceiver of SSB, VHF etc. In the case of using the only 1 private line which is exchanged voice signal with data signal had mixed or interrupted for up/down of channel, PTT control and monitoring of transmission channel and power. The up/down of channel and PTT control is according to the ASK and the data of monitoring is transfered to the FSK modulation, additional algorithm is studied on the serial protocol and traffic sequence using the MCS-51 processor in the simplex communication methode.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39A no.12
• /
• pp.691-698
• /
• 2014

An L-band single side band(SSB) mixer with CMOS switches and a C-band quadrature voltage-controlled oscillator(QVCO) have been developed using the TowerJazz 0.18-um RFCMOS process. The SSB mixer exhibits a conversion gain of 6.6 ~ 7.5 dB with a 70-dBc image rejection ratio and 65-dBc port isolation. The oscillation frequency range of the QVCO is 6.2 ~ 6.7 GHz with an output power of 4~6 dBm. For measurement, 1.8 V supply voltage is used while drawing 36 mA for the mixer and 23 mA for the QVCO.

• Journal of Oral Medicine and Pain
• /
• v.39 no.3
• /
• pp.90-95
• /
• 2014

Purpose: To investigate viscosity and wettability of hyaluronic acid (HA) solutions according to supplementation of lysozyme and/or peroxidase, and different ionic strength and pH conditions. Methods: Solutions containing HA were prepared using distilled deionized water (DDW) and simulated salivary buffer (SSB) in different conditions. Different concentrations of hen egg-white lysozyme and bovine lactoperoxidase was added into HA solutions. HA solutions with antimicrobials in different ionic strength and pH conditions were prepared. Viscosity was measured using cone-and-plate digital viscometer at six different shear rates and wettability on acrylic resin and Co-Cr alloy was determined by contact angle. Results: The viscosity values of HA dissolved in DDW were decreased in order of HA, HA containing lysozyme, HA containing peroxidase, and HA containing lysozyme and peroxidase. The viscosity values for HA in DDW were decreased as the concentration of lysozyme and/or peroxidase increased. However, the viscosity values for HA in SSB showed no significant changes according to the concentration of lysozyme and/or peroxidase. The viscosity values of HA solutions were inversely proportional to ionic strength and pH. The contact angle of HA solutions showed no significant differences according to tested surface materials, addition of lysozyme and/or peroxidase, and different ionic strength and pH conditions. Contact angles on acrylic resin by HA solutions in all tested conditions were much higher than those by human saliva. Conclusions: The rheological properties of HA supplemented with lysozyme and/or peroxidase in different ionic strength and pH conditions were objectively confirmed, indicating the possibility of HA with lysozyme and/or peroxidase as main components in the development of effective saliva substitutes.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2002.10a
• /
• pp.169-169
• /
• 2002

The mobilizable amount of transition metals is a fraction of the total amount of the metal from urban particulate matter. Although the fraction is small, some metals (Fe, Cu) are the major participants in a reaction that generates reactive oxygen species (ROS), which can damage various biomolecules. Damaging effects of the metals can be measured by the single strand breakage (SSB) of X174 RFI DNA or the carbonyl formation of protein. In another study, we have shown that more metals are mobilized by PM2.5 than by PM10 in general. DNA SSB of >20% for PM2.5 and >15% for PM10 was observed in the presence of chelator (EDTA or citrate)/reductant (ascorbate), compared to the control (<3%) only with the chelator. The carbonyl formation by both PMs was very similar in the presence of the chelator, regardless of the kind of proteins. Compared to the control in the absence of chelator/reductant, 3.3 times and 4.9 times more carbonyl formation for PM2.5 and PM10, respectively, was obtained with BSA in the presence of chelator/reductant, showing that PM10 induced 33% more damage than PM2.5. However, 4.8 times and 1.9 times more carbonyl formation for PM2.5 and PM10, respectively, was observed with lysozyme in the presence of chelator/reductant, showing that PM2.5 induced 250% more damage than PM10. Although different proteins showed different sensitivities toward ROS, all these results indicate that the degrees of the oxidation of or damage to the biomolecules by the mobilized metals were higher with PM2.5 than with PM10. Therefore, it is expected that more metals mobilized from PM2.5 than from PM10, more damage to the biomolecules by PM2.5 than by PM10. We suggest that when the toxicity of the dust particle is considered, the particle size as well as the mobilizable fraction of the metal should be considered in place of the total amounts.

• Journal of Radiation Protection and Research
• /
• v.20 no.2
• /
• pp.71-78
• /
• 1995

To develop methods to reduce radiation risk and apply such knowledge to improvement of radiation protection, the effects of cobaltous chloride known as bioantimutagen on the function of E. coli RecA protein involved in the repair of DNA damage were examined. The results demonstrated two distinct effects of cobaltous chloride on the RecA protein function necessary for the strand exchange reaction. Cobaltous chloride enhanced the ability of RecA protein to displace SSB protein from single-stranded DNA and the duplex DNA-dependent ATPase activity. RecA protein was preferentially bound with UV-irradiated supercoiled DNA as compared with nonirradiated DNA The binding of RecA protein to UV-irradiated supercoiled DNA was enhanced in a dose-dependent manner. It is likely that studies on the factors affecting repair efficiency and the DNA repair proteins may provide information on the repair of ionizing radiation-induced DNA damage and the mechanism for DNA radioprotection.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.1C
• /
• pp.73-81
• /
• 2005

We propose an automatic modulation recognition scheme which extracts pre-defined key features from the received signal and then applies equal gain combining method to determine the used modulation. Moreover, we compare and analyze the performance of the proposed algorithm with that of decision-theoretic algorithm. Our scheme extracts five pre-defined key features from each data segment, a data unit for the key feature extraction, which are then averaged over all the segments to recognize the modulation according to the decision procedure. We check the performance of the proposed algorithm through computer simulations for analog modulations such as AM, FM, SSB and for digital modulations such as FSK2, FSK4, PSK2, and PSK4, by measuring recognition success rate varying SNR and data collection time. The result shows that the performance of the proposed scheme is comparable to that of the decision-theoretic algorithm with less complexity.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.6C
• /
• pp.632-639
• /
• 2002

To reduce the area and power consumption in constant coefficient multiplications, the constant coefficient can be encoded using canonic signed digit(CSD) representation. When the partial product terms are added depending on the nonzero bit(1 or -1) positions in the CSD-encoded multiplier, all sign bits are properly extended before the addition takes place. In this paper, to reduce the overhead due to sign extension, a new method is proposed based on the fact that carry propagation in the sign extension part can be controlled such that a desired input bit can be propagated as a carry. Also, a fixed-width multiplier design method suitable for CSD multiplication is proposed. As an application, 43-tap filbert transformer for SSB/BPSK-DS/CDMA is implemented. It is shown that, about 16∼28% adders can be saved by the proposed method compared with the conventional methods.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.1
• /
• pp.191-200
• /
• 2000

The marine accident is being highlighted as a serious worldwide problem for the guard station of human safety and the protection of marine environment pollution. Especially, the GMDSS is operated as a international rule for the safety of a large scale ship, but the small size ship's management is required a adaptive national rule because of the complex condition of national circumstance. This study is motivated to develop a ship's position tracking system combined with GPS information for VTS and control the ship navigation, velocity and longitude etc.. In Part of Navigation Data Transmission is GPS data transmission whih ship's ID using microprocessor and TX speed translation for flexibility with 4800∼2400 [bps]. Results show that the our system for data transmission using microprocessor is useful tool in maritime transmission as SSB used the main TX method of small ship and has a cost competitive power. Therefore, we will expected cost and technical competitive power compared to AIS. But those systems are still remained the unsolved problem for protection from marine accident.. Finally, we examined the semi-actual receiving state on simulated sailing in the around sea of Mok-Po harbor.