• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.7
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• pp.76-81
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• 2011

A new via cutting structure in 2-layer DRAM package substrate has been fabricated to lower its power distribution network(PDN) impedance. In new structure, part of the via is cut off vertically and its remaining part is designed to connect directly with the bonding pad on the package substrate. These via structure and substrate design not only provide high routing density but also improve the PDN impedance by shortening effectively the path from bonding pad to VSSQ plane. An additional process is not necessary to fabricate the via cutting structure because its structure is completed at the same time during a process of window area formation. Also, burr occurrence is minimized by filling the via-hole inside with a solder resist. 3-dimensional electromagnetic field simulation and S-parameter measurement are carried out in order to validate the effects of via cutting structure and VDDQ/VSSQ placement on the PDN impedance. New DRAM package substrate has a superior PDN impedance with a wide frequency range. This result shows that via cutting structure and power/ground placement are effective in reducing the PDN impedance.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.73-81
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• 2011

As high speed digital systems continue to use components with faster edge rate and clock speeds, transmission of the digital information, it can bring about many troubles. The increasing requirement for controlled impedance PCBs becomes both a critical success factor and a design challenge to implement a system. Especially, the noise sources in high frequency digital systems include the noise in power supply, ground and packaging, and they destroy the fidelity of signals. Therefore PCB design with impendence matching is needed to improve fidelity of signal in H/W. In this paper, we have developed an impedance control and analysis tool for multi-layer PCB design, and simulates the tracks controlled impedance with the test coupon. So, it can save the design time and support the economical PCB design.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.370-376
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• 2021

development of the aerospace industry is increasing the research of projectiles. In addition, many tests are under way and many failures occur accordingly. Projectiles should be able to minimize failures because they are more dangerous than other electronic equipment. Therefore, it is necessary to verify wiring before powering the projectile. Accordingly, the wiring status was verified by resistance measurements. However, the wiring test of the previous resistance measurement method cannot be accurately measured due to devices such as capacitors and inductors in the projectile circuit. In this paper, impedance is measured in the connection state of cables and projectiles using a TDR meter. The Z-Segmentation algorithm is used to set the reference value for the measured steady state impedance. The Z-Segmentation algorithm first finds the peak values of the impedance waveform using a Kalman filter and obtains the final impedance peak segment through segmentation. In this way, the wiring status is determined based on the reference value for the normal state of the wiring.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.60-64
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• 1996

This paper describes the development of portable arousal measurement and analysis system. Skin impedance change which responds the change of arousal level was detected by the three electrode constant current method and separated into two components (SIR, SIL). Relationship between Nz, IRI and arousal level was studied and Criteria of arousal level control was decided by the sleep study.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.141-143
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• 1992

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.871-872
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.433-434
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• 2010

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.251-254
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• 2000

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.5
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• pp.25-31
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• 2014

Bioelectrical Impedance Analysis(BIA) is a widely used method for estimating body composition changes which is a non-invasive, inexpensive, safety and reproductive method. We studied the bioimpedance change and the distinction of blood pressure according to body posture and conducted three kinds of experiments: the real-time bioimpedance measurement, the simulation using equivalent circuit model and the blood pressure measurement. Bioimpedance is measured during 4 minutes at the multi-frequency(1 kHz, 10 kHz, 20 kHz, 50 kHz, 70 kHz, 100 kHz). From the experiment results, the changes in body postures result in changes of resistance and reactance, with an average rapid increase of body impedance when going from standing, sitting to supine. Specially, the laying resistance on average was 16.49% higher than supine resistance at 50 kHz and the laying reactance measurement was also 26.05% higher than sitting reactance at 1 kHz. Blood pressure in standing posture was higher than those in other postures both in maximum($125.14{\pm}12.30$) and in minimum($75.57{\pm}10.31$). The results of BIA and blood pressure in this study will be contributed to the research on acute illness, extreme fat, and body shape abnormalities.

• Journal of the Korea Concrete Institute
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• v.21 no.2
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• pp.153-158
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• 2009

Using non-invasive surface measurement method, the corrosion state of steel embedded inside concrete can be measured by placing four electrodes on the surface of concrete. Modeling of such measurements can provide valuable information as how interfacial impedance between corroded steel and surrounding concrete results in measured impedance on the concrete surface. In this paper, the modeling of surface measurement technique is used for the determination of the sensitivity of the measurements with respect to steel bar size embedded inside concrete and cover thickness. Modeling results indicated that steel bar sizes varied from D10 to D35 could be identified. Concrete cover thickness changes from 0.02 m to 0.1 m was also distinguished using the modeling scheme. The results confirm this modeling technique is capable of determining steel bar sizes and cover thickness, as well as simulating corrosion responses.