• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.11 s.102
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• pp.1086-1098
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• 2005

Two types of small wideband antennas are proposed for UWB application. One type is small biconical structure fed by coaxial probe, which is easy to be installed on the circuit board. The other type is of planar bow-tie type fed by coplanar transmission line. Generally, the bandwidth of the latter type is significantly narrower than that of the former type. It is shown, however that the bandwidth of the latter type can be made to be comparable to that of the former, if some series inductive component is introduced in the center conductor line in the CPW transmission line by replacing some part of center line with narrower line of higher characteristic impedance. The series inductance component play an important role of neutralizing the capacitive component of the small bow-tie antenna, thereby making broadband impedance matching possible. The small planar bow-tie antenna was fabricated and experimented. The experimental results for return loss are observed to be in good agreement with simulated results. The radiation pattern is also investigated experimentally.

• Journal of the Korean Electrochemical Society
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• v.7 no.4
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• pp.206-210
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• 2004

All array of carbon paste-based electrodes was prepared by screen printing the carbon paste modified with metal oxides $(TiO_2,\;RuO_2,\;PbO_2,\;Ni(OH)_2)$ and Prussian blue (PB). An electronic tongue system was assembled with the carbon-paste electrode array, and applied to discriminate the tastes of various commercial beverages and foods by measuring the chronoamperometric responses to the samples diluted in 0.1M carbonate buffer (pH 9.6). The results were analyzed with principal component analysis(PCA) method and plotted on two dimensional PCA coordinate; it was apparent that the amperometric electronic tongue system could discriminate the types of various foods and beverages.

• Culinary science and hospitality research
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• v.21 no.1
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• pp.235-249
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• 2015

This study was carried out to investigate the flavor changes of Lentinus edodes at different storage temperatures, time and natural additives using an electronic nose with six metal oxide sensors. To preserve good quality of modified atmosphere packaged Lentinus edodes, Four natural additives(Artemisia princeps, Artemisia capillaries, green tea, and activated charcoal) were used. The mushrooms were packaged in polyethylene films with each treatment and were stored at 5, 10 and $20^{\circ}C$. Increase in storage temperature and storage time decreased the ratio of resistance in the electronic nose as well as first principal component scores. In addition, indicating quality of mushroom reduced at high temperature and long storage time. The results of the electronic nose and the principal component analysis(PCA) in the mushrooms with Artemisia princeps and Artemisia capillaries that were stored at $5^{\circ}C$, and green tea and activated charcoal which were stored at $10^{\circ}C$ showed the good effects to maintain the freshness along with reducing off-flavor. However, there were no differences between control and treatment groups at $20^{\circ}C$.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.203-209
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• 2007

As the vehicle electronic control technology quickly grows and becomes more sophisticated, a more efficient means than the traditional in-vehicle driving test is required for the design, testing, and tuning of electronic control units (ECU). For this purpose, the hardware-in-the-loop simulation (HILS) scheme is very promising, since significant portions of actual driving test procedures can be replaced by HIL simulation. The HILS incorporates hardware components in the numerical simulation environment, and this yields results with better credibility than pure numerical simulations can offer. In this study, a HILS system has been developed for ESP (Electronic Stability Program) ECUs. The system consists of the hardware component, which that includes the hydraulic brake mechanism and an ESP ECU, the software component, which virtually implements vehicle dynamics with visualization, and the interface component, which links these two parts together. The validity of HIL simulation is largely contingent upon the accuracy of the vehicle model. To account for this, the HILS system in this research used the commercial software CarSim to generate a detailed full vehicle model, and its parameters were set by using design data, SPMD (Suspension Parameter Measurement Device) data, and data from actual vehicle tests. Using the developed HILS system, performance of a commercial ESP ECU was evaluated for a virtual vehicle under various driving conditions. This HILS system, with its reliability, will be used in various applications that include durability testing, benchmarking and comparison of commercial ECUs, and detection of fault and malfunction of ESP ECUs.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.40-54
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• 2006

It's not easy to detect the high quality and functional compounds for control quality of food materials. The electronic nose was an instrument, which comprised of an array of electronic chemical sensors with partial specificity and an appropriate pattern recognition system, capable of recognizing simple or complex odors. It can conduct fast analysis and provide simple and straightforward results and is best suited for quality control and process monitoring in the field of functional foods. Numbers of applications of an electronic nose in the functional food industry include discrimination of habitats for medicinal food materials, monitoring storage process, lipid oxidation, and quality control of food and/or processing with principal component analysis, neural network analysis and the electronic nose based on GC-SAW sensor. The electronic nose would be possibly useful for a wide variety of quality control in the functional food and plant cultivation when correlating traditional analytical instrumental data with sensory evaluation results or electronic nose data.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.31-34
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• 1996

A new analysis method is presented for the steady state response of electronic ballast circuit. Comparisons and examination among self exited LCC, LLCC resonant converter of electronic ballast for fluorescent lamp in expect of soft starting, component stress shot of are presented. In this paper, the theoretical discussions and analysis are verified by experimental measurements

• Food Science and Biotechnology
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• v.14 no.3
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• pp.437-439
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• 2005

Freshness of stored soybean curd as sensitivity ($R_{gas}/R_{air}$) was evaluated at 48-50 hr intervals using electronic nose at regular sequential square-wave temperatures between $4\;-\;10^{\circ}C$. Obtained kinetic data from apparent first principal component score $(PC1)_{app}$ and storage time were used for prediction of freshness. Percentage difference between predicted and actual values of stored soybean curd was less than 8.9% under fluctuating temperature condition.

• Journal of Sensor Science and Technology
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• v.11 no.5
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• pp.279-285
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• 2002

Two $SnO_2$ based sensing films(pure $SnO_2$ and $SnO_2$/Pt) and a Pt thin film for temperature sensor on an alumina substrate were designed and fabricated for classifying the indoor environmental gases. By controlling the heating power in the shape of trapezoid, unique four sensing response curves created from both $SnO_2$ film and $SnO_2$/Pt film. Then, various parameters were extracted from sensing response curves and carried out principal component analysis(PCA). The results confirm that a sensor array with the proposed operating mode was extremely effective in classifying indoor environmental gases such as $CO_2$, $C_3H_8$, $C_4H_{10}$.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1063-1068
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• 2004

A numerical study is performed to predict the effect of operating conditions on the thermal response of electronic assemblies during infrared reflow soldering. The multimode heat transfer within the reflow oven as well as within the electronic assembly is simulated, and the predictions illustrate the detailed thermal responses. Parametric study is performed to determine the thermal response of electronic assemblies to various conditions such as conveyor speed, exhaust velocity, and component emissivity. The predictions of the detailed electronic assembly thermal response can be used in selecting the oven operating conditions to ensure proper soldering and minimization of thermally-induced electronic assembly stresses.

• Journal of Applied Reliability
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• v.9 no.1
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• pp.37-45
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• 2009

Recently mechanical watt-hour meters are being replaced by electronic watt-hour meters. The replacement period of mechanical watt-hour meters is 7 years. This period is based on long term historical data. The replacement period of electronic watt-meters is also 7 years. This period is determined using the replacement period of mechanical watt-hour meters. However lifetime of mechanical watt-hour meters is different from the lifetime of electronic meters. In order to determine desirable replacement period of electronic watt-hour meters, accelerated life tests of major components in electronic watt-hour meters were performed. The test results showed that LCD was the component which had the shortest lifetime. In this paper, lifetime of electronic watt-hour meters manufactured by 3 company was estimated and life test standard for LCD was developed.