• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.18 no.3
• /
• pp.189-203
• /
• 2008

Cylindrical bag filter system with pulse jet cleaning has been the most common device to control particle laden exhaust gas from the various industrial processes. But, it has many shortcomings due to particle reattachment and frequent bag rupture. In recent years, rectangular type bag filter system has been developed to overcome the problems associated with the cylindrical system. However, not many studies about the rectangular system were not done, compared to the cylindrical system. In this study, the optimum pulse jet cleaning conditions were thus tested by the series of experiments. The factors tested in this study are pulse distance, pulse pressure, pulse duration, the number of holes for pulsing and bag materials. A single bag ($1,500mmL{\times}50mmW{\times}300mmH$) system and a multi-bags (3 bags in a row) were tested separately. The highest removal efficiency with a single bag system was found at the conditions with pulse distance of 10cm, pulse pressure of $3kg/cm^2$, pulse duration of 0.3s, pulse jet number of 6 and Polyester bag. With the multi-bags system, the best cleaning conditions were found at the bag interval of 20cm with the simultaneous pulsing and the bag interval of 15cm with the serial pulsing.

• Korean Journal of Acupuncture
• /
• v.26 no.2
• /
• pp.1-13
• /
• 2009

Objective: Optical Coherence Tomography (OCT) has emerged as an important optical imaging modality in non-invasive medical diagnostics. Hence, the aim of this study is to measure the similarity of the diagnosis by a traditional method using doctor's hand for feeling of pulse and by the non-contact/non-invasive pulse analyzing system using OCT on Chon(寸), Kwan(關), Chuk(尺). Method: Four korean medical doctors and the non-contact/non-invasive pulse analyzing system using OCT have measured the rapidity, the dimension, and the power of pulse waves of 25 volunteers. First, four korean medical doctors measured pulse waves of volunteers. During measuring, four doctors were separated from each other and so were volunteers. And then, the pulse waves of volunteers were measured by OCT. This was performed on the right Chon(寸), Kwan(關), Chuk(尺). Results: The study showed that the traditional method and the OCT based method had the 88% matches on the values of the slow and rapid pulse condition (遲數), 64% matches on the values of the small and big pulse condition(微細弱緩大[洪]), and 72% matches on the values of the weak and strong pulse condition(虛實). Conclusions: Based on the high similarities of the measurements of two approaches, we suggest that the OCT based pulse diagnosis method is useful for compensating the traditional method for the pulse diagnosis.

• Journal of Sensor Science and Technology
• /
• v.22 no.6
• /
• pp.439-443
• /
• 2013

A wireless optical fiber interferometer arterial pulse wave sensor system is developed for remote sensing. The wireless optical fiber sensor system consists of Zigbee communication modules and an optical fiber interferometer arterial pulse wave sensor. The optical fiber arterial pulse wave sensor is an in-line Michelson interferometer enclosed with steel reinforcement in a heat-shrinkable tube. The Zigbee communication modules are composed of an ATmega128L microprocessor and a CC2420 Zigbee chip. The arterial pulse waves detected by the optical fiber sensor were transmitted and received via the Zigbee communication modules. The experimental results show that the wireless optical fiber sensor system can be used for monitoring the arterial pulse waves remotely.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.54 no.5
• /
• pp.238-244
• /
• 2005

This paper proposes a new configuration of 36-pulse voltage source converter which consists of two 6-pulse bridges and a pulse-interleaving auxiliary circuit. The system topology of proposed converter was derived to increase the pulse number of converter output voltage without increasing the number of 6-pulse bridges. The gate pulse generation was analyzed using the theoretical approach of multi-pulse switching converter, The operational feasibility of proposed system was verified by computer simulations with PSCAD/EMTDC software and experimental works with 2kVA hardware prototype. The proposed converter can be widely used for the uninterruptible power supply, the power quality compensator, and the distributed power generation, such as solar and fuel cell power system.

• Proceedings of the KIEE Conference
• /
• 2004.11b
• /
• pp.31-35
• /
• 2004

This paper proposes a new configuration of 36-pulse voltage source converter which consists of two 6-pulse bridges and a pulse-interleaving auxiliary circuit. The system topology of proposed converter was derived to increase the pulse number of converter output voltage without increasing the number of 6-pulse bridges. The gate pulse generation was analyzed using the theoretical approach of multi-pulse switching converter. The operational feasibility of proposed system was verified by computer simulations with PSCAD/TMTDC software and experimental works with 3kVA hardware prototype. The proposed converter can be widely used for the uninterruptible power supply, the power quality compensator, and the distributed power generation, such as solar and fuel fell power system.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.3
• /
• pp.120-126
• /
• 2005

The Korean Superconducting Tokamak Advanced Research (KSTAR) tokamak device is being constructed to perform long-pulse, high-beta, advanced tokamak fusion physics experiments. The long-pulse operation requires the non-inductive current drive system such as the Lower-Hybrid Current Drive (LHCD) system. The LHCD system drives the non-inductive plasma current by means of C-band RF with 2-MW CW power and 5-GHz frequency. For the LHCD test experiments, an RF test system is developed. It is composed of a 5-GHz, 1.5-MW pulsed magnetron and a compact pulse modulator with $4\;{\mu}s$ of pulse width. The pulse modulator provides the maximum output voltage of 45 kV and the maximum current of 90 A. It is composed of 7 stages of Pulse Forming Network (PFN), a thyratron tube (E2V, CX1191D), and a pulse transformer with 1:4 step-up ratio. In this paper, the detailed design and the performance test of the pulse modulator are presented.

• Korean Journal of Oriental Medicine
• /
• v.13 no.3
• /
• pp.105-110
• /
• 2007

This work reports the pulse diagnosis system using FBG sensors which can display pulse signals detected while oriental medical doctors are conducting pulse diagnoses and simultaneously pressing the sensors by three fingers. Each optical fiber has five FBG sensing units fabricated in 2 mm width and 2 mm inter-sensor spacing. Three optical fibers with the FBG units in the parallel line configuration are then placed on each finger-pressing region and thus overall 9 fibers are used for the pulse measurements on the so-called "chon", "gwan", and "ch대k". A fixture holding the optical fiber arrays is able to adjust the height of the FBG sensing units while placing the fibers on the wrist. The pulse signals detected by the FBG sensors from chon, kwan, and chuk have been analyzed using 4 channel spectrum analyzer connected to the optical fibers. The measured pulse signals exhibit variations due to the nonuniform pressure distributions applied. resulting in the differences in the detected pulse signals between fiber lines. However. this work is the first step towards objective and quantitative analyses of the pulse diagnosis in oriental medicine which has traditionally been performed on subjective basis. Future works will be devoted to improving sensor stability, developing the way applying pressure and algorithms reporting the objective classification of the pulse status from systemic measurements using the sensors instead of relying on the clinicians' diagnoses subjectively performed. A successful pulse diagnosis system emerging in the future is expected to contribute to education as well as promoting pulse diagnosis in oriental medicine to the scientific research area.

• Korean Journal of Artificial Intelligence
• /
• v.6 no.1
• /
• pp.11-15
• /
• 2018

The purpose of this study is to develop a pulsatile drowsiness detection system that can compensate the limitations of existing camera - based or breathing pressure sensor based Drowsiness driving prevention systems. A heart rate sensor mounted on the driver's finger and an alarm system that sounds when drowsiness is detected. The heart rate sensor was used to measure pulse changes in the wrist, and an alarm system based on the Arduino, which works in conjunction with the laptop, generates an audible alarm in the event of drowsiness. In this paper, we assume that the pulse rate of the drowsy state is 60 ~ 65 times / minute, which is the middle between the awake state and the sleep state. As a result of the experiment, the alarm sounded when the driver's pulse rate was in the drowsy pulse rate range. Based on these experiments, the drowsiness detection system was able to detect the drowsiness of the driver successfully in real time. A more effective drowsiness prevention system can be developed in the future by incorporating the results of the present study on a pulse-based drowsiness prevention system in an existing drowsiness prevention system.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1355_1357
• /
• 2009

This paper describes the standard system for calibrating pulse generator of partial discharge(PD) and its uncertainty. The system is consisted of digital pulse generator, digital recorder and evaluation software. The uncertainty requirement of calibrator charge is less than $\pm$ (0.1pC + 0.03q) and that of pulse duration is less than $\pm$ 10 %. The system can generate various kind of calibration pulses such as single pulse, double pulses, oscillation pulse, long-duration pulse, random pulses and evaluate their uncertainty.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.12
• /
• pp.2351-2357
• /
• 2008

Noninvasive radial artery pulse wave has been widely used not only for the pulse wave analysis(PWA) itself but also for assessment of arterial stiffness with estimated aortic pulse wave from peripheral pulse wave. However, it has been found that the deformation of pulse shape can be caused readily by changing measuring position, indentation pressure, and so on. So, in this study, we have developed a system which can measure radial pulse wave and skin displacement simultaneously while the indentation body goes down to occlude subject's radial artery. This system can be divided into a measuring apparatus part, an indentation control hardware part, a data acquisition part and a control and computation part. And, the measuring apparatus consists of an arm-rest, a step motor, an indentation body, a laser displacement sensor(LK-G30, Keyence Co.) and pulse wave sensor. Under load-free condition and radial artery loaded condition, the evaluation of developed system has been performed. From these results, we can conclude: 1) The developed system can control the indentation body quantitatively and the adopted laser displacement sensor shows linear output characteristic even with skin as a reflector. 2) This system can measure the pulse wave and the displacement of indentation body, that is, skin displacement simultaneously at each specific level of indentation body. 3) This system can provide the number of motor steps used to get down the indentation body, the measured skin displacement, the calculated indentation pressure, the calculated pulse pressure and the pulse waveform as well as the information generated by combining these with each others. 4) This system can reveal the relationship between the morphological changes of pulse wave and the estimated displacement of radial artery wall by indentation. Consequently, the developed system can furnish more abundant information on radial artery than previous diagnosis systems based on tonometric measurement. In further study, we expect to setup the standard measuring process and to concrete the algorithm for the estimation of radial artery's diameter and of displacement of radial artery's wall. Furthermore, with well designed clinical studies, we hope to turn out the usefulness of developed system in the field of cardiovascular system evaluation.