• Smart Structures and Systems
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• v.19 no.3
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• pp.269-277
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• 2017

Recently, there has been significant interest in structural health monitoring for civil engineering applications. In this research, a specially designed tendon, proposed by embedding FBG sensors into the center king cable of a 7-wire strand tendon, was applied for long-term health monitoring of tensile forces on a ground anchor. To make temperature independent sensors, the effective temperature compensation of FBG sensors must be considered. The temperature sensitivity coefficient ${\beta}^{\prime}$ of the FBG sensors embedded tendon was successfully determined to be $2.0{\times}10^{-5}^{\circ}C^{-1}$ through calibrated tests in both a model rock body and a laboratory heat chamber. Furthermore, the obtained result for ${\beta}^{\prime}$ was formally verified through the ground temperature measurement test, expectedly. As a result, the ground temperature measured by a thermometer showed good agreement compared to that measured by the proposed FBG sensor, which was calibrated considering to the temperature sensitivity coefficient ${\beta}^{\prime}$. Finally, four prototype ground anchors including two tension ground anchors and two compression ground anchors made by replacing a tendon with the proposed smart tendon were installed into an actual slope at the Yeosu site. Tensile forces, after temperature compensation was taken into account using the verified temperature sensitivity coefficient ${\beta}^{\prime}$ and ground temperature obtained from the Korean Meteorological Administration (KMA) have been monitored for over one year, and the results were very consistent to those measured from the load cell, interestingly.

• Journal of Sensor Science and Technology
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• v.17 no.1
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• pp.1-8
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• 2008

Recently, capsule endoscope was developed to observe small intestine in human body. However, the capsule does not have any locomotive ability, which reduces the benefit of the capsule endoscope. Many researches have done to give locomotion to the capsule, still it consumes too much power to generate the motion by small battery. One of the moving method is electrical stimulus that consumes less power than many methods. The electrical stimulus method causes contraction in the small intestine, and it moves the capsule. Some of papers showed it is possible to guide the capsule by electrical stimulus, however the relationship between electrical stimulus at the mucous and contraction force in the small intestine is not reported, yet. In this paper, the mucous in the small intestine was stimulated, and measured the contraction force in the small intestine is shown. The result shows, the relationship between electrical stimulus parameters (voltage, duration) and contraction force. Also, equation between electrical stimulus parameters and contraction force is roughly induced.

• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1363-1373
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• 2014

In this study, a hybrid multi-cup electric cupping system (HMECS) was proposed, based on the ancient cupping method. HMECS consisted of several cups that could be used simultaneously to treat different areas of the patient's body. Each cup was equipped with its own pump and pressure-monitoring system. Moreover, the vacuum pressure of the cups was controlled using fuzzy logic. Through automated control of the vacuum pressure, long-term relief of muscle tightness was achieved. To develop a scientific foundation for this alternative treatment, we compared the VAS(Visual Analog Scale) and ODI(Oswestry Disability Index) scores from conventional basic cupping to the VAS and ODI scores for our proposed HMECS. The improvement rate in the VAS and ODI scores using HMECS after three treatments was higher than that achieved by basic cupping. These results, combined with the convenience offered by enhanced IT capabilities, should increase the popularity of this device among an aging society, and facilitate the opportunity to further explore the potential of Oriental medical practices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1229-1235
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• 2014

At the LPG vehicle air intake system, most of dust particles in the air cleaner are removed. However very small particles are not removed and accumulated. The accumulation of carbon in air intake system is going to affect the idle speed control and sensor signal. It also causes engine chattering and transmission troubles of automatic transmission. This is study about cleaning up intake system using cleaning chemical. We can clean up the intake system by spraying cleaning liquid onto intake device when the engine is idling after intake hose is removed from warmed up vehicle. We can obtain the following experimental results by cleaning up ISC, surge tank, intake manifold, intake valves and combustion chamber. According to this results, the stroll valve works correctly and power rate of engine is up to the standard, it is smoothy to control the idling speed when a vehicle pulls up. After cleaning up CO grow down about 0.15%, HC does about 20~100 ppm.

• Journal of Biosystems Engineering
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• v.37 no.5
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• pp.314-318
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• 2012

Purpose: This study was conducted to develop a measurement system for determining photosynthetic photon flux (PPF) distribution and illumination efficiency of LED lamps. Methods: The system was composed of a linear moving sensor part (LMSP), a rotating part to turn the LMSP, a body assembly to support the rotating part, and a motor controller. The average PPF of the LED lamp with natural cooling and water cooling was evaluated using the measurement system. Results: The PPF of LED lamp with water cooling was 3.1-31.7% greater than that with natural cooling. Based on the measured value, PPF on the horizontal surface was predicted. Illumination efficiency of the LED lamp was slightly increased with water cooling by 3.4%, compared with natural cooling. A simulation program using MATLAB was developed to analyze the effects of the vertical distance from lighting sources to growing bed, lamp spacing, and number of LED lamps, on the PPF distribution on the horizontal surface. The uniformity of the PPF distribution of the LED lamps was fairly improved with 15 cm spacing, as compared to the 5 cm spacing. By simulation, PPF of $217.0{\pm}27.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was obtained at the vertical distance of 40 cm from six LED lamps with 12 cm spacing. This simulated PPF was compared to the measured one of $225.9{\pm}25.6{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. After continuous lighting of 346 days, the relative PPF of LED lamps with water cooling and natural cooling was decreased by 6.6% and 22.8%, respectively. Conclusions: From these results, it was concluded that the measurement system developed in this study was useful for determining PPF and illumination efficiency of artificial lighting sources including LED lamp.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.113-117
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• 2012

Purpose: The purpose of this study was to analyze the weight bearing of the cane and foot for the different walking aids during walking. Methods: A total of 12 subjects (6 males, 6 female) with stroke were enrolled in the study. Foot sensor and an instrumented cane were integrated to analyze the vertical peak force on the foot and cane. Results: The vertical peak force applied on the quad cane gait resulted in a significantly higher rate, which was $10.60{\pm}6.48%$ of the body weight, when compared to that of mono cane gait which was $7.91{\pm}4.11%$. The results indicated significantly lower vertical peak force on the affected foot, without the help of a walking aid, as compared to that of walking with a cane (respectively, p<0.05). However, results showed that the differences in vertical peak force on the affected foot, between mono cane and quad cane, were not significant. Conclusion: In conclusion, the vertical peak forces were significantly greater, during a comparison between walking with a quad cane and walking with a mono cane. On the contrary, no significant difference in the vertical peak force on the affected foot between walking with quad cane and walking with a mono cane. Muscle activation pattern and walking pattern should be measured in future studies, to study the differences between walking with various walking aids in the lower and higher functioning hemiparetic subjects, as its use may mask underlying gait impairment.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.313-318
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• 1998

Electro-Optical Camera(EOC) is the main payload of Korea Multi-Purpose SATellite(KOMPSAT) with the mission of cartography to build up a digital map of Korean territory including Digital Terrain Elevation Map(DTEM). This instrument which comprises EOC Sensor Assembly and EOC Electronics Assembly produces the panchromatic images of 6.6 m GSD with a swath wider than 17 km by push-broom scanning and spacecraft body pointing in a visible range of wavelength, 510 ~ 730 nm. The high resolution panchromatic image is to be collected for 2 minutes during 98 minutes of orbit cycle covering about 800 km along ground track, over the mission lifetime of 3 years with the functions of programmable rain/offset and on-board image data storage. The image of 8 bit digitization, which is collected by a full reflective type F8.3 triplet without obscuration, is to be transmitted to Ground Station at a rate less than 25 Mbps. EOC was elaborated to have the performance which meets or surpasses its requirements of design phase. The spectral response the modulation transfer function, and the uniformity of all the 2592 pixel of CCD of EOC are illustrated as they were measured for the convenience of end-user. The spectral response was measured with respect to each gain setup of EOC and this is expected to give the capability of generating more accurate panchromatic image to the EOC data users. The modulation transfer function of EOC was measured as greater than 16% at Nyquist frequency over the entire field of view which exceeds its requirement of larger than 10%, The uniformity that shows the relative response of each pixel of CCD was measured at every pixel of the Focal Plane Array of EOC and is illustrated for the data processing.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.3
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• pp.197-202
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• 2010

In this paper, multi-channel vital signal monitoring system was implemented for home healthcare. The system able to measure vital signal for example ECG, PPG and temperature simultaneously at patients’ home. The vital signal is an essential parameter for healthcare application and can be easily extracted from patients. The implemented system consist of sensor parts for signal extraction, signal amplifier and filter for analog circuit, analog signal to digital conversion for controlling devices and lastly the monitoring program. The system able to transmit vital signals using Bluetooth wireless communications to personal computer or home server. And the tele-monitoring system able to display real-time signals using web monitoring program. In medical application, the vital signal parameter able to stored and saved in the web server for further medical analysis. This system opens up the possibilities of ubiquitous healthcare where further implementation can be easily done.

• Journal of Sensor Science and Technology
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• v.6 no.6
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• pp.466-475
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• 1997

In this paper, an implantable middle ear hearing aids using an electromagnetic transducer which consists of a tiny coil and a magnet is designed, and objective design method to implement a vibrator of the electromagnetic type transducer is proposed. Sound characteristic of the electromagnetic type vibrator is excellent but power transfer rate is lower than that of a ceramic type. To improve power transfer efficiency of system, external and inner part of a middle ear system is designed using FM transmission method. We implemented an experimental set of the designed transducer, inner part, and outer part. Then, we measured vibration characteristics of a metal strip and a temporal bone of a dead body. As the results, we confirmed the advantage of FM method and showed that designed transducer could effectively transmit vibration of amplified input sound pressure to ossicle.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.687-695
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• 2007

Statement of problem: The proper contact relation between adjacent teeth in each arch plays an important role in the stability and maintenance of the integrity of the dental arches. Proximal contact has been defined as the area of a tooth that is in close association, connection, or touch with an adjacent tooth in the same arch. Purpose: The aim of this study was to develop a digital device for measuring the proximal tooth contact tightness by pulling a thin stainless steel strip (2mm wide, 0.03mm thick) inserted between proximal tooth contact. Material and method: This device consists of measuring part, sensor part, motor part and body part. The stainless steel strip was connected to a stain gauge. The strain gauge was designed to convert the frictional force into a compressive force. This compressive force was detected as a electrical signal and the electrical signal was digitalized by a A/D converter. The digital signals were displayed by a micro-processor. The pulling speed was 8mm/s. Results: For testing reliability of the device in vivo, two healthy young adults (A, B) participated in this experiment. The tightness of proximal tooth contact between the second premolar and the first molar of mandible (subject A) and maxilla (subject B) was measured fifteen times for three days at rest. We double-checked the accuracy of the device with a Universal Testing Machine. Output signals from the Universal Testing Machine and the measuring device were compared. Regression analysis showed high linearity between these two signals. In vivo test, no significant differences were found between measurements. Conclusion: This device has shown to he capable of producing reliable and reproducible results in measuring proximal tooth contact. Therefore, it was considered that this device was appropriate to apply clinically.