• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.7
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• pp.607-616
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• 2002

This study has been conducted to evaluate the applicability of the control method in the dehumidification-integrated radiant floor cooling system in terms of stability of the room air temperature and the control variables through experiments. To do this, the relationship between the control variables in preventing floor surface condensation is first analyzed and the control method is predetermined through simulations. The results are as follows. First, it is necessary to determine the operation status of the dehumidification system according to the relationship between floor surface temperature and dew point temperature in the conditioned space. Second, outdoor reset with indoor temperature feedback control is better than on/off bang-bang control with respect to temperature stability in controlling the room air temperature and the possibility of energy savings. Finally, the humidity sensor can be located with the current thermostat in that there are small differences in absolute humidity in vertical distribution.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1271-1280
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• 2000

A sensor placement technique to identify structural parameter was developed. Experimental results must be acquired to identify unknown dynamic characteristics of a targeting structure for the comparison between analytical model and real structure. If the experimental environment was not equipped itself properly, it can be happened that some valuable information are distorted or ill-condition can be occurred. In this work the index to determine exciting points was derived from the criterion of maximizing parameter sensitivity matrix and that to choose measurement points was from that of preserving the invariant of sensitivity matrix. This idea was applied to a compressor hull structure to verify its performance. The result shows that the selection of measurement and excitation points using suggested criteria improve the ill-conditioning problem of inverse type problems such , as model updating.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.459-464
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• 2009

This study has been conducted on how to determine the multi-evaporator vapor compression cycle system is charged correctly by using sensor readings which are used to control system. In this paper, the characteristics of the multi-evaporator were presented and sensor values were classified using fuzzy clustering. finally classification logic and it's performance were discussed by applying commercial VRF system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.102-109
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• 1997

A study to determine a proper sensor placement was developed to improve force identification. Improper selection of response position cause erroneous result in force identification problem. This paper presents two methods to improve the conditioning of the system's FRM(Frequency Response Matrix) which affects the accuracy of result. The basic strategy of the two methods in selecting the response position is to let the smallest singular value be as large as possible by maximizing the orthogonality of FRM. The suggested methods are tested numerically with a fixed-fixed beam model. The test results show that the proposed methods are very effective in dealing with the force identification problem.

• Journal of Biosystems Engineering
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• v.28 no.4
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• pp.335-342
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• 2003

A simple disposable thick-film potentiometric strip has been developed and evaluated for hydroponics application. The strip consisted of low ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, and magnesium were measured with specially designed 16-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The thick-film sensors exhibit linear relationships over five concentration decades. The concentration of N $O_3$ - ion in standard solution can be determined by direct potentiometric measurements without any conditioning before measurements. However, measurement of $K^{+}$, N $H_4$$^{+}$, and $Mg^{2+}$ ionic concentrations in nutrient solutions seems not feasible.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.449-456
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• 2006

The purpose of urodynamic investigation is to obtain the information on the function of the urinary system. The aim of this study is to acquire the useful information of lower urinary tract symptom (LUTS) diagnosis through void force signal as noninvasive method. The system which could evaluate the function of compensatory hypertrophy with noninvasive and comfortable method was implemented to measure uroflow and void force during urination. The implemented system composes of the sensor parts, signal conditioning parts and PC monitoring program. For the evaluation of the implemented system, the simulation of control part of the system was performed and the model system for the lower urinary system was designed. The superiority of a measuring characteristic of the implemented system was verified using the model system. From the evaluation of the model system, we have found out that the void force was dependent on the occlusion degree and compensatory hypertrophy significantly.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.49-50
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• 2012

Maximum power point tracking(MPPT) algorithm is needed in PV AC module power conditioning system because of the nonlinear current-voltage characteristics. Conventional MPPT algorithm is required to know PV-module output current and voltage. Thus, PV-AC module must have voltage and current sensor. In this paper, a current-sensorless MPPT algorithm, which uses only the voltage sensor, is presented for Flyback inverter.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1977-1987
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• 2008

In this paper, presented was the research work of finding practical application systems using IT that would be adopted by the next generation high speed train for the safety, convenience, and comfort of the passengers and crew members. Study on the applications using smart sensors and IT brought up 26 feasible application cases. Among them 16 cases were related with IT applications and 10 cases smart sensor applications. After having public hearings and surveys to make the decision more objective and generally acceptable, 7 applications - such as information providing service using personal LCD monitor, alarm service, individual internet access service, automatic and remote air conditioning, wireless visual communication with an attendant, extraordinary sound detection, urgent situation in toilet monitoring - out of those 26 were chosen as the final applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.805-806
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.279-280
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• 2008