• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.4
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• pp.346-360
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• 1992

This paper proposed a method of identity decision of moving object by the fuzzy inference. Moving object is extracted by the difference picture method and identity decision parameters of moving object are chosen area, perimeter. A/p ratio and vertex. In the brightness variation of 600 Lux-1600Lux, we determined the maximum error often parameters and then generated a fuzzified data. Fuzzified data are generated from the reference image and then decided the identity of extracted parameter by the fuzzy inference using fuzzy production rule. In order to verify validity of proposed method, experiment are performed with a toy car. As a result, it was shown that decision error was less than 4%

• YAKHAK HOEJI
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• v.48 no.6
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• pp.379-383
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• 2004

Biphenyl dimethyl dicarboxylate (DDB) has been used for the treatment of chronic viral hepatitis B and drug-induced hepatitis through the inhibition of lipid peroxidation and c ovalent binding of drug metabolites to lipids of microsomes. The bioequivalence of two DDB products was evaluated according to the guidelines of KFDA. The test product was Hepaphil soft capsule(R) made by KMS Pharm. Co. Containing 3 mg DDB and the reference product was Nissel tablet(R) made by Taerim Pharm. Co. Containing 25 mg DDB. Twenty healthy male subjects, 25.4(22~30) years old and 66.7(54~77)kg, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After two tablets or two capsules were orally administered, blood was taken at predetermined time intervals and the concentration of DDB in plasma was determined using a validated HPLC method with UV detector. Two pharmacokinetic parameters, $AUC_t$ and $C_{max}$, were calculated and analyzed statistically for the evaluation of bioequivalence of the two products. Analysis of variance was carried out using logarithmically transformed parameter values. The 90% confidence intervals of $AUC_t$ and $C_{max}$ were log 0.91~log1.00 and log 1.05~log 1.15, respectively. These values were within the acceptable bioequivalence intervals of log 0.8 to log 1.25. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating that Hepaphil soft capsule is bioequivalent to Nissel tablet.

• The Journal of the Acoustical Society of Korea
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• v.8 no.4
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• pp.65-73
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• 1989

In this paper, we propose a text-independent speaker identification algorithm based on VQ(vector quantization) and vowel classification, and its performance is studied and compared with that of a conventional speaker identification algorithm using VQ. The proposed speaker identification algorithm is composed of three processes: vowel segmentation, vowel recognition and average distortion calculation. The vowel segmentation is performed automatlcally using RMS energy, BTR(Back-to-Total cavity volume Ratio)and SFBR(Signed Front-to-Back maximum area Ratio) extracted from input speech signal. If the Input speech signal Is noisy, particularity when the SNR is around 20dB, the proposed speaker identification algorithm performs better than the reference speaker identification algorithm when the correct vowel segmentation is done. The same result is obtained when we use the noisy telephone speech signal as an input, too.

• International Journal of Fluid Machinery and Systems
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• v.9 no.3
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• pp.229-236
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• 2016

Exergetic analysis was introduced in optimization of a rotating equilateral triangular internal cooling channel with staggered square ribs to maximize the net exergy gain. The objective function was defined as the net exergy gain considering the exergy gain by heat transfer and exergy losses by friction and heat transfer process. The flow field and heat transfer in the channel were analysed using three-dimensional Reynolds-averaged Navier-Stokes equations under the uniform temperature condition. Shear stress transport turbulence model has been selected as a turbulence closure through the turbulence model test. Computational results for the area-averaged Nusselt number were validated compared to the experimental data. Three design variables, i.e., the angle of rib, the rib pitch-to-hydraulic diameter ratio and the rib width-to-hydraulic diameter ratio, were selected for the optimization. The optimization was performed at Reynolds number, 20,000. Twenty-two design points were selected by Latin hypercube sampling, and the values of the objective function were evaluated by the RANS analysis at these points. Through optimization, the objective function value was improved by 22.6% compared to that of the reference geometry. Effects of the Reynolds number, rotation number, and buoyancy parameter on the heat transfer performance of the optimum design were also discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.37-41
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• 2018

In this paper, we evaluate the power consumption of IEEE802.15.4e TSCH which uses the specific link scheduling scheme proposed in reference[1]. And we also compares it with the power consumption of conventional single channel IEEE802.15.4. The power consumption of IEEE802.15.4e TSCH is smaller than the conventional one under the any conditions of traffic. The reasons can be explained as the followings. Firstly, TSCH does not have backoff time because of using the collision free link scheduling. Secondly, there is the timing difference of MAC offset parameter between TSCH and conventional IEEE802.15.4 Lastly, the devices in TSCH mode sleep during the time slots which are not assigned to itself.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.4-9
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• 1999

A new control method for precision robust position control of a brushless DC (BLDC) motor using asymptotically stable adaptive load torque observer is presented in the paper. Precision position control is obtained for the BLDC motor system approximately linearized using the field-orientation method Recently, many of these drive systems use BLDC motors to avoid backlashe. However, the disadvantages of the motor are high cost and complex control because of nonlinear characteristics. Also, the load torque disturbance directly affects the motor shaft. The application of the load torque observer is published in [1] using fixed gain. However, the motor flux linkage is not exactly known for a load torque observer. There is the problem of uncertainty to obtain very high precision position control. Therefore a model reference adaptive observer is considered to overcome the problem of unknown parameter and torque disturbance in this paper. The system stability analysis is carried out using Lyapunov stability theorem. As a result, asymptotically stable observe gain can be obtained without affecting the overall system response. The load disturbance detected by the asymptotically stable adaptive observer is compensated by feedforwarding the equivalent current which gives fast response. The experimenta results are presented in the paper.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.3
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• pp.199-207
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• 2018

In this paper, an all-metal domestic induction heating (IH) system that can quickly identify ferromagnetic and non-ferromagnetic pots considering temperature changes in the working coil is designed. Load modeling is performed after analyzing the parameters of the pot material and the central misalignment of the working coil. To improve the performance and stability of the all-metal IH cooking heater, a power curve-fitting model is used to design a control system that quickly responds to load parameter fluctuations. In addition, a power control algorithm is established to compensate for the reference value by reflecting the increase in working coil temperature during heating of the non-ferromagnetic pot. The validity of the proposed control algorithm for the all-metal IH is verified by experiments using a 3.2 kW all-metal IH cooking heater.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.77-92
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• 2003

A set of standard triaxial testing was performed to identify underlying physical processes and inherent limitations in the determination of critical state parameters in sandy soils. The experimental test results showed that the critical state friction angle for a given soil is constant regardless of drainage condition while the critical state line on the e-log p'space is significantly affected by drainage condition mainly because of insufficient strain attained in standard triaxial tests and strain localization effects in udrained tests. It appeared that the best method to determine critical state parameters in laboratory testing is to use homogeneous loose specimens under drained shear condition. In addition, a reference state parameter was suggested to design tests that will avoid dilatancy or strain localization effects in drained tests.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.24-30
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• 2003

In this paper, we propose a novel predictive control method, which uses a wavelet neural network as a predictor, for the control of chaotic systems. In our method, we use the gradient descent method for training the parameter of a wavelet neural network. The control signals are directly obtained by minimizing the difference between a reference signal and the output of a wavelet neural network. To verify the efficiency of our method, we apply it to the Doffing and the Henon system, which are a representative continuous and discrete time chaotic system respectively, and compare with the results of generalized predictive control using multi-layer perceptron.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.3 s.234
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• pp.418-424
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• 2005

We present the design, fabrication and experimental results of 4-bit digital microinjectors, whose ejected droplet volumes are adjusted by the digital operation of a 4-bit microheater array. We design the reference microinjectors as well as its comparative test structures. In the fabrication process, we use a five-mask micromachining process and the total chip size of the fabricated microinjector is $7,640{\mu}m{\times}5,260{\mu}m.$ We measure the ejected droplet volumes and velocities, which are adjusted from $12.1{\pm}1.0~55.6{\pm}14.7pl\;and\;2.3{\pm}0.1~15.7{\pm}0.8m/s.$ respectively, depending on the 15 possible combinations of 4-bit microheater array. We also experimentally characterize the effect of geometric variation including the microheater size, inter-microheater gap, microchannel width and sequential operation of microheater array on the ejected droplet volume and velocity. Among these parameters, we find that the microheater size is the most dominant parameter affected to the ejected droplet volumes and velocities. Thus, the present microinjector has a potential for application to the high-resolution inkjet printers with multiple gray levels or high-precision fluid injectors with variable volume control.