• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.262-266
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• 2011

A simulation study of a current-mode direct current (DC)-DC boost converter is presented in this paper. This converter, with a fully-integrated power module, is implemented by using bipolar complementary metal-oxide semiconductor (BiCMOS) technology. The current-sensing circuit has an op-amp to achieve high accuracy. With the sense metal-oxide semiconductor field-effect transistor (MOSFET) in the current sensor, the sensed inductor current with the internal ramp signal can be used for feedback control. In addition, BiCMOS technology is applied to the converter, for accurate current sensing and low power consumption. The DC-DC converter is designed with a standard 0.35 ${\mu}m$ BiCMOS process. The off-chip inductor-capacitor (LC) filter is operated with an inductance of 1 mH and a capacitance of 12.5 nF. Simulation results show the high performance of the current-sensing circuit and the validity of the BiCMOS converter. The output voltage is found to be 4.1 V with a ripple ratio of 1.5% at the duty ratio of 0.3. The sensing current is measured to be within 1 mA and follows to fit the order of the aspect ratio, between sensing and power FET.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.62-67
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• 2009

For diagnoses of digestive organs, capsule endoscopes are widely used and offer valuable information without patient's discomfort. A general capsule endoscope which consists of image sensing module, telemetry module and battery is able to move along gastro-intestinal tracts passively only through peristaltic waves. Thus, it is likely to have some limitations for doctor to acquire images from the desired organs and to diagnose them effectively. As solutions to these problems, a locomotive function of capsule endoscopes has being developed. We have proposed a capsule-type microrobot with synchronized multiple legs. However, the proposed capsular microrobot also has some limitations, such as low speed in advancement, inconvenience to controlling the microrobot, lack of an image module, and deficiency in a steering module. In this paper, we will describe the limitations of the locomotive microrobot and propose solutions to the drawbacks. The solutions are applied to the capsular microrobot and evaluated by in-vitro tests. Based on the experimental results, we conclude that the proposed solutions are effective and appropriate for the locomotive microrobot to explore inside intestinal tracts.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.2
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• pp.1-8
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• 2011

An underwater robot S/W framework consists of various sub-modules such as sensory data processing module, thruster control module, cognition module and behavior control module. Performance of a robot is determined by not only the efficiency of algorithms used but also effectiveness of their implementations. One most important factor of the effective implementation is the efficiency of data sharing module, as it transmits signals and data between the sub-modules and thus is directly related to the cycles of sensing and control The ideal data sharing module enables immediate access to any data source irrespective of system configurations. In reality, however, there are lots of obstacles including limitation of processing capacity of source modules, delay over network, and scheduling latency of operating systems. The paper proposes a new data sharing architecture and programming models to effectively handle such obstacles in implementation of underwater S/W framework on a small scale distributed computing system.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.72-76
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• 2009

The sensing system was designed and fabricated to investigate the ferment environment of soybeans. $NH_3$ gas was saturated after about 7 h and $CO_2$ gas was reached the peak after about 8 h in the inoculation of Bacillus subtilis. However, times that $CO_2$ gas and $NH_3$ gas were reached maximum value without Bacillus subtilis were about 15 h and 18 h, respectively. The sample that inoculated Bacillus subtils had deeper taste than one without it. We found that the peak time of $CO_2$ gas means the starting time of fermentation. If we control the operating time after the start of fermentation, it is expected to make a suitable Chungkukjang to individual preference.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.176-180
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• 2007

In this study, we deployed the cable tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway can be applied to cable tunnel monitoring system. Sensors considered herein are flame detection sensor, flood detection sensor, intruder detection sensor, and temperature sensor, etc. It is also found that the wireless sensor network can deliver sensing data reliably by wireless sensing technology. The gateway system that can transmit sensed data to server by CDMA is developed. Monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. The system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system is infeasible.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1180-1185
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• 2009

Database is constructed according to the development of information contents technology. But the construction of database using bio-information has not been developed. because it is difficult to collect bio-information. This paper presents how to construct database about sensing temperature and tilt of cow based on bio-information using RF communication. The system consists of 8bit micro-controller, tilt sensor, temperature sensor and RF module.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.432-435
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• 2004

MSC (Multi Spectral Camera) system is a remote sensing payload to obtain high resolution ground image. In this application, uniformity characteristic is important as well as GSD (Ground Resolved Distance) and SNR (Signal to Noise Ratio). MSC image chain is consisted of OM (Optical Module), CCD, Video processor, NUC and DCSU (Data Compression and Storage Unit). Each block makes and corrects MSC's nonuniformity response. This paper shows the cause of nonuniformity error and the correction scheme of MSC system from the electronic point of view.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.91-94
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• 2006

In this paper, we deployed the tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway system can be applied to tunnel monitoring system. Sensors included herein are acceleration transducers, fire-alarm sensors, water-level sensors, and magnetic contact sensors. It is also found that the wireless sensor network can deliver sensing data reliably by ad-hoc networking technology. The gateway system that can send the sensing data to server by CDMA (code division multiple access) is developed. Finally, monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. Furthermore, the above system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system cannot be applied.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1650-1660
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• 2016

This paper proposes a compensator to eliminate the DC bias of inductor current. This method utilizes an average-current sensing technique to detect the DC bias of inductor current. A small signal model of the DC bias compensation loop is derived. It is shown that the DC bias has a one-pole relationship with the duty cycle of the left side leading lag. By considering the pole produced by the dual active bridge (DAB) converter and the pole produced by the average-current sensing module, a one-pole-one-zero digital compensation method is given. By using this method, the DC bias is eliminated, and the stability of the compensation loop is ensured. The performance of the proposed compensator is verified with a 1.2-kW DAB converter prototype.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.479-480
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• 2007

It is study about implementation of the home network system that used an ubiquitous sensor network and an embedded system in this paper. PXA270 and CC2420 were used, and the home server of a wireless sensor home network system composed it. A wireless control system is composed of a gas valve, a DC motor, a lamp and a door rock. A wireless detection system is composed of a gas detection sensor, a movement detection sensor, an extension detection sensor The wireless detection system that was an environment sensing system was composed of temperature, humidity, mic, illuminance, a speed-up, infrared rays temperature sensing module, and modular, other RFID established an USB camera, and an ubiquitous home network was composed.