• Proceedings of the KSME Conference
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• 2004.11a
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• pp.678-683
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• 2004

In this study, a experiment has been developed for measuring the exhaust pressure of muffler at inlet and outlet. The main experimental parameters were a engine speed and sound absorbing material in the muffler. The muffler sound absorbing material tested a steel wool and glass wool. The exhaust pressure was measured with pressure sensor. The phase of exhaust pressure with high speed was moved according to increasing engine speed comparing with exhaust pressure with low speed. Also, the distribution of exhaust pressure at the model-1, 2 and 3 are similar with distribution of exhaust pressure at muffler inlet.

• Journal of information and communication convergence engineering
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• v.6 no.4
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• pp.454-458
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• 2008

It can improve human being's life quality that all people can have more convenient medical service under pervasive computing environment. For a pervasive health care application for diabetes patient, we've implemented a health care system, which is composed of three parts. Various sensors monitor both outer and inner environment of human such as temperature, blood pressure, pulse, and glycemic index, etc. These sensors form zigbee based sensor network. And medical information server accumulates sensing values and performs back-end processing. To simply transfer these sensing values to a medical team is a low level's medical service. So, we've designed a new service model based on back propagation neural network for more improved medical service. Our experiments show that a proposed healthcare system can give high level's medical service because it can recognize human's context more concretely.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.789-795
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• 2008

Slope stability is affected by various factors. For safety management of slopes, monitoring systems have been widely constructed along railway lines. The representative data from the systems are variations of ground profile such like ground water level and pore water pressure etc. and direct displacement measured by ground clinometer and tension wire sensor. Slopes are mainly effected by rainfall and rainfall causes the decrease of factor of safety(FOS). Because FOS varies linearly by the variation of ground water level and pore pressure, it has a weak point that could not define the time and proper warning sign to secure the safety of the train. In this study, alternative of FOS such as reliability index and probability of failure is applied to slope stability analysis introducing the reliability concept. FOS, reliability index, probability of failure and velocity of probability of failure of the slopes by variation of ground water level are investigated for setting up the specification of safety management of slopes. By executing case study of a slope(ILLO-IMSUNGLI), it is showed to be applied to specification of safety management.

• Transactions of the Society of Information Storage Systems
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• v.8 no.1
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• pp.16-21
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• 2012

SAW device is widely used as filters, sensors, actuators in various technologies. And capacitive sensor is tremendously used to measure pressure, gap, etc. The application of SAW device as signal conditioner of capacitive sensor reduces noise level and enables high precision measurement. The response increase of SAW based capacitive sensor is produced just before the two capacitive electrode contacts by the existence of parasitic resistance of capacitive electrode. In this paper, we analyze the effects of parasitic resistance and propose the calibrating method using lumped component and execute the high precision gap measurement using calibrated system. And xx nm resolution and yy ${\mu}m$ stroke was attained.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1039-1040
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• 2010

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.11
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• pp.657-661
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• 2003

In this paper, we designed a portable digital pressure algometer which not only can measure the pain level objectively and quantitatively, but also is able to do RF communication. This system consists of pressure sensor for pain measurement, analog signal analysis, digital hardware based on PIC16C73B, RF communication and display. To evaluate the performance of the developed system, we measured pressure threshold using commercial analog PA(Pressure Algometer) and the proposed system, and then evaluated the correlation and confidence. Using linear regression analysis, standard deviation of 0.1731 and R-square value of 99.3% were obtained. In conclusion, the above results showed good performance and its usability in measuring the pain clinically.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1452-1461
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• 2020

A triple bubbler sensor was tested in LiCl-KCl molten salt from 450 to 525 ℃ in a transparent furnace to validate thermal-expansion corrections and provide additional molten salt data sets for calibration and validation of the sensor. In addition to these tests, a model was identified and further developed to accurately determine the density, surface tension, and depth from the measured bubble pressures. A unique feature of the model is that calibration constants can be estimated using independent depth measurements, which allow calibration and validation of the sensor in an electrorefiner where the salt density and surface tension are largely unknown. This model and approach were tested using the current and previous triple bubbler data sets, and results indicate that accuracies are as high as 0.03%, 4.6%, and 0.15% for density, surface tension, and depth, respectively.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.113-125
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• 2008

To test if the developed ubiquitous health care devices working well and vital information could be collected and monitored systematically through internet and to test if the devices and services could be used further. Kyungwon University, KT Co., Gil Medical Center, LIG Nex1 Co., and Sujeong Health Center conducted an ubiquitous health care demonstration project in Sujeong-Gu, Sungnam, Korea from Mar. 5 to May 16. We developed and applied several medical devices to monitor health of the elderly in their houses through internet. The devices were sphygmomanometer, glucometer, body fat scale, Health Pad, and activity sensor. We distributed the devices to 20 recipients of home care and 7 diabetes patients. After received the devices and were explained how to use them, they used the devices in their houses. The vital signs of the residents were monitored through internet. A nurse monitored and consulted their vital signs in the monitoring center in Kyungwon University during the demonstration period. The consultant called them and consulted on their blood pressure, blood sugar level, and body fat after a few seconds they used the devices as well as provision of recommended contents such as diets and activities through Health Pad. To investigate cognition and satisfaction of the participants for the devices, we surveyed the participants at the end of the demonstration period. For the change in blood pressure, blood sugar level, and activities, we conducted statistical test. After the demonstration period. cognition and satisfaction for the devices and change in blood pressure, blood sugar level, and activities were evaluated. Most of the participants were acknowledged how to use the device and satisfied with the use of the devices. The internet monitoring and services are considered to be promising because most of the participants were satisfied especially because somebody was monitoring their health status. However some weaknesses such as short battery life of the activity sensor, lack of connection of consultations with hospitals, and low understanding on usage of some of the devices need to be complemented.

• Advances in nano research
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• v.15 no.3
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• pp.239-251
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• 2023

In the present study, we aim to use nanotechnology sensors/actuators to capture pressure and frequency of voice singers and to send signals for improving breathing pressure. In this regard, a circular composite structure having 3 different layers are used. The core layer is nano-composite material reinforced with graphene nanoplatelets. The face sheets are piezo electric materials connected to electrical circuit capable of measuring and applying voltage to the piezoelectric layers. This sensors have extremely smaller size than conventional sensors attached to the neck of singer and, hence, minimizes the influences on the output voice of the singer. A brief theoretical framework are presented for nonlocal strain gradient theory and geometry of the sensor is described in detail. The controlling procedure along with experimental results on 20 amateur and professional singer participants are also presented. The results of the study indicate that the participants could gain benefit from the device for improving their ability in phonation and keeping their frequency at a constant level although they have difficulty in the beginning of the experiment getting used to the device.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.285-290
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• 2013

As well as the advanced development of modern society, and the environmental problems caused by the use of fossil fuels is emerging. So do not reap the performance level of the car to be able to replace existing fossil fuel and low-emission energy and technology development are continually strives. Therefore, this study aims to present the direction of the new interface 21st century Mobile Auto Electric Segway technology in the field of security and disadvantages based. The Segway is a problem because the control itself skewed by certain slope where the slope in the wrong adjustment tipping. In this study, the year saw the introduction of two pressure sensors(Load cell) used to solve these drawbacks, according to the ratio of the weight control methods. In addition, the ramps operate in a straightforward, using an acceleration sensor and a gyro sensor in order to compensate for the slope value in free control method to study looked. Measured by calculating the value of the occupant's weight and according to the inclination of the pressure sensor pressure sensing experiment results this year, we can see that the control variable for the change in body weight is greater than the inclination. Segway is also easy to control, and the stability of the ramps, etc. As a result, created using a pressure sensor.