• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.1
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• pp.82-86
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• 2002

It is demonstrated that the conventional current-pulse laser drivers are not adequate in driving VCSELs operating at multi-Gb/s speeds. Simulation results, including the bonding parasitics, show that high-performance VCSELs are more efficiently driven using voltage-pulse mode of operation. The optical output power is almost doubled in the voltage-mode of operation, while the total electrical power consumption of the transmitter decreases by 20%.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.281-284
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• 2007

We have analyzed the short pulse generation using heterodyne techniques. The numerical model for semiconductor lasers under the heterodyne technique is based on the Lang's equation and has been extended in order to take into account the simultaneous injection of the multiple sidebands of the current-modulated laser. The unselected sidebands will affect the optical and RF-spectral characteristics even when the semiconductor laser is locked to the target sidebands.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1053-1055
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• 1998

Using EMTP model which describes bipolar HVDC system, switching level simulation results are presented in this paper. Voltage synchronization at point of common coupling, gate pulse generation and current control loops are represented in TACS module. The system consists of 100 km submarine cable rated 300 MW and 12 pulse rectifier and inverter stations which are connected to equivalent three-phase sources and loads through the 154 kV AC lines, respectively. In convertor stations, harmonic filters and capacitor banks are equipped to cancel out the harmonics generated by converters and to supply the required reactive power.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.185-188
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• 2001

This paper proposes an error amplifier circuit using OTA(Operational Transconductance Amplifier) which is the main constituent element in pulse width modulation circuit. The proposed OTA error amplifier circuit is featured by simple circuit configuration, excellent high frequency characteristics and bias current controlled output. Through the experiment of pulse width modulation circuit, the validity of the operation of the OTA error amplifier circuit is verified.

• The Journal of Internal Korean Medicine
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• v.29 no.3
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• pp.535-542
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• 2008

Objectives : Ryodoraku, which is a physiological function test using electric current, is closely related to skin sympathetic tone. Pulse analysis is known to reflect cardiovascular reactivity. Refer to the previous researches Ryodoraku and pulse analysis have value as tools for diagnosing respiratory diseases. In this study we examined the diagnostic values of Ryodoraku and pulse analysis for respiratory disease patients. Methods : For this study. we conducted Ryodoraku and pulse analysis on 114 people, including 83 respiratory disease outpatients and 31 volunteers who did not have any respiratory symptoms or disease history. The respiratory patients were divided into three subgroups according to their symptoms: rhinorrhea group, cough-sputum group and wheezing-dyspnea group. Then we compared the disease groups with the control group. Results : When all experimental groups were compared with the control group, mean Ryodoraku was significantly lower. Mean H2, mean H3 and mean H6 were significantly lower in the rhinorrhea group (P<0.05), all the test results of Ryodoraku were evidently lower in the cough-sputum group (P<0.01), and most results of Ryodoraku were evidently lower in the wheezing-dyspnea group except H1 (P<0.01). Compared with the control group on pulse analysis, mean YP+/YP- was significantly lower in the wheezing-dyspnea group (P<0.05). Conclusion : Ryodoraku and pulse analysis were found to have a high value as quantitative diagnosis tools reflecting individuals' weakness and firmness. Nevertheless, more research is needed to find the further values.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.560-569
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• 2007

Objectives : Ryodoraku is a physiological function test using electric current, and is closely related to skin sympathetic tone. Pulse analysis is known to reflect cardiovascular reactivity. There has been no report on the correlation between ryodoraku and pulse analysis in respiratory diseases. The present study examined the diagnostic values of ryodoraku and pulse analysis for respiratory disease patients Methods : For this study, we conducted ryodoraku and pulse analysis in 103 people including 79 respiratory disease outpatients who visited the $5^{th}$ Internal Department of the Oriental Medicine Hospital of Kyung Hee University during the period from January 1, 2003 to July 25, 2006, and 24 volunteers who did not have any respiratory symptoms or disease history. The respiratory disease patients were divided into five sub-groups according to their symptom: cough-sputum group, wheezing-dyspnea group ' nasal symptoms group. cold-prone group, and fatigue prone group. We compared the disease groups with the control group in six items as follows : mean ryodoraku, mean H1, mean elastic index, the percentage of those with mean ryodoraku below $40{\mu}A$, the percentage of those with HI beyond the physiological range, and the ratio of left : right of elastic index Results and Conclusions : Ryodoraku and pulse analysis were found to have a high value as quantitative diagnosis tools reflecting individuals' weakness and firmness. The results of this research suggest that ryodoraku and pulse analysis have value as tools for diagnosing respiratory diseases.

• Journal of IKEEE
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• v.21 no.4
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• pp.375-380
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• 2017

A differential current-to-time interval converter is presented for current mode sensors. It consists of a ramp voltage generator, a current mode sensor, a reference current source, two current-tunable Schmitt triggers, a one-shot multivibrator, and two logic gates. The design principle is to apply a ramp voltage to each input of the two current-tunable Schmitt triggers whose threshold voltages are proportional to the drain current values of the current mode sensors. A proposed circuit converts a current change in the ISFET biosensor into its equivalent pulse width change. A prototype circuit built using TSMC 0.18 nm CMOS process exhibit a conversion sensitivity amounting to $726.9{\mu}s/pH$ over pH variation range of 2-12 and a linearity error less than ${\pm}0.05%$.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1114-1116
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• 2002

The characteristics of voltage drop and THD for parallel operating 11 PCRs (Phase Controlled Rectifiers) are analysed. The PCRs are used to drive high current (1.6 kA ${\sim}$ 3.7 kADC) electromagnetic coils for electromagnets. All the PCRs operate simultaneously in pulsed mode, and the pulse shot occurs every 150 seconds. During the pulse operation the PCR output current ramps up for 4 seconds, and then keeps flat top state for 2 seconds, and finally ramps down for 4 seconds. For the flat top mode a severe voltage drop and distortion appear in the power system because transformers for the PCRs are designed considering pulsed mode operation. It is expected that the analysis method can be applied to improve the system performance including power factor and design of high power pulsed mode operating power supply systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.149-152
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• 2004

A new joint source channel coding reduces both input-width and average current consumption to transmit image data to LCD source drivers. As a source coding, it is based on entropy coding of differential pulse code modulation scheme, especially using median edge detector of image predictor. As a channel coding, it is not a simple pulse amplitude modulation, but linked by source entropy to reduce average amplitude. Simulation results show 1/4 width is achievable by 16-valued transmission with keeping conventional current consumption (0.36 to 1.3).

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.332-335
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• 1990

There are several methods in controlling resonant converters to regulate the output with low switching losses. In this paper, Pulse-width modulation method or current controlled method is applied to regulate the output with low switching losses. In digital implementation of resonant converter systems, the speed of the applied processor is very critical since the switching frequency is very high. Thus the various possible candidates of microprocessors are evaluated for the implementation of resonant converter systems. Then too design methods and techniques are desioribed when single chip processor is used to simplify hardware requirements.