• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.9C
• /
• pp.871-876
• /
• 2005

In this paper, we propose an improved partial response maximum likelihood (PRML) detection scheme that has an adaptive equalizer and can be applied in the asymmetric optical recording system with high-density. We confirmed that the proposed PRML detector improves detection performance. In addition, we implemented the detector by Verilog HDL. The adaptive equalizer is composed of tap coefficient updating unit using LMS algorithn and FIR filter. FIR filter is implemented by the transposed direct form architecture for high speed operation. Viterbi detector is implemented by the register exchange method.

• Fashion & Textile Research Journal
• /
• v.6 no.5
• /
• pp.595-604
• /
• 2004

This study is to investigate complaining behavior of consumers who purchase fashion products on the internet, as well as to find how the complaining behaviors are related to the consumers' characteristics. The subjects of this study are limited to the consumers who have experienced dissatisfaction when purchasing fashion products through the internet. The questionnaires were administered to male and female respondents using the internet shopping mall. The results can be summarized as follows: The factor analysis shows that consumer complaining behaviors are fitted well into four factors(direct complaining behavior, private complaining behavior, third-party complaining behavior, and no response). In the difference analysis by consumer's complaining behavior styles and gender, private complaining and third-party complaining behavior were significant statistically. In the difference analysis between consumer's complaining behavior styles and internet self-efficacy. Internet self-efficacy was significantly different according to consumer's complaining behavior styles, especially for direct complaining, third-party complaining and no response. Private complaining behavior, third-party complaining behavior and no response were negatively related to consumer retention, while direct complaining behavior was not.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.17 no.3
• /
• pp.253-262
• /
• 2013

Objectives This study is on the quantifying method for the acupuncture-moxa cautery heat response index, which are based on the some definitions. Methods The magnitude of the acupuncture-moxa cautery is defined by the pain-feeling of the acupuncture-moxa cautery stimulation: the stimulation magnitude of the acupuncture is 1, that of the direct moxa-cautery is 2, and that of the indirect moxa-cautery is 0.5. The heat variation of the acupuncture-moxa cautery stimulation is defined by the heat variations of the characteristic points pre/post-stimulations in the stenosis of the lumber. The acupuncture-moxa cautery heat response index is defined by the ratio of between the magnitude of the heat variation and the natural logarithmic magnitude of the stimulation. Results With the respect of the acupuncture-moxa cautery heat response index, I experimented and estimated 4 types of stimulations in the stenosis of the lumber: the single acupuncture stimulation with 40%, the single direct moxa-cautery stimulation with 52%, the combinational acupuncture-moxa cautery stimulations with 27%, and the combinational acupuncture-indirect electronic moxa-cautery stimulations with 53%. Conclusions According to the acupuncture-moxa cautery heat response index. the combinational acupuncture-moxa cautery stimulations especially need to be changed to the combinational acupuncture-indirect electronic moxa-cautery stimulations.

• Journal of IKEEE
• /
• v.23 no.2
• /
• pp.628-635
• /
• 2019

This paper proposes sliding mode control (SMC) method for improvement of dynamic response for IPMSM based on DTC with constant switching frequency. DTC with constant switching frequency method consists of PI torque controller and triangular comparator for constant torque error status. It has the poor dynamic response compared to conventional DTC. This paper proposes improvement method of dynamic response of DTC with constant switching frequency by using SMC. Simulation results confirm the effectiveness of the proposed method.

• Journal of Radiation Protection and Research
• /
• v.41 no.3
• /
• pp.229-236
• /
• 2016

Background: In order to manage the patient exposure dose in X-ray diagnosis, it is preferred to evaluate the entrance skin dose; although there are some evaluations about entrance skin dose, a small number of report has been published for direct measurement of patient. We think that a small-type optically stimulated luminescence (OSL) dosimeter, named nanoDot, can achieve a direct measurement. For evaluations, the corrections of angular and energy dependences play an important role. In this study, we aimed to evaluate the angular and the energy dependences of nanoDot. Materials and Methods: We used commercially available X-ray diagnostic equipment. For angular dependence measurement, a relative response of every 15 degrees of nanoDot was measured in 40-140 kV X-ray. And for energy dependence measurement, mono-energetic characteristic X-rays were generated using several materials by irradiating the diagnostic X-rays, and the nanoDot was irradiated by the characteristic X-rays. We evaluated the measured response in an energy range of 8.1-75.5 keV. In addition, we performed Monte-Carlo simulation to compare experimental results. Results and Discussion: The experimental results were in good agreement with those of Monte-Carlo simulation. The angular dependence of nanoDot was almost steady with the response of 0 degrees except for 90 and 270 degrees. Furthermore, we found that difference of the response of nanoDot, where the nanoDot was irradiated from the randomly set directions, was estimated to be at most 5%. On the other hand, the response of nanoDot varies with the energy of incident X-rays; slightly increased to 20 keV and gradually decreased to 80 keV. These results are valuable to perform the precise evaluation of entrance skin dose with nanoDot in X-ray diagnosis. Conclusion: The influence of angular dependence and energy dependence in X-ray diagnosis is not so large, and the nanoDot OSL dosimeter is considered to be suitable dosimeter for direct measurement of entrance surface dose of patient.

• Structural Engineering and Mechanics
• /
• v.32 no.2
• /
• pp.283-300
• /
• 2009

The characteristic response of a structure to blast load may be divided into two distinctive phases, namely the direct blast response during which the shock wave effect and localized damage take place, and the post-blast phase whereby progressive collapse may occur. A reliable post-blast analysis depends on a sound understanding of the direct blast effect. Because of the complex loading environment and the stress wave effects, the analysis on the direct effect often necessitates a high fidelity numerical model with coupled fluid (air) and solid subdomains. In such a modelling framework, an appropriate representation of the blast load and the high nonlinearity of the material response is a key to a reliable outcome. This paper presents a series of calibration study on these two important modelling considerations in a coupled Eulerian-Lagrangian framework using a hydrocode. The calibration of the simulated blast load is carried out for both free air and internal explosions. The simulation of the extreme dynamic response of concrete components is achieved using an advanced concrete damage model in conjunction with an element erosion scheme. Validation simulations are conducted for two representative scenarios; one involves a concrete slab under internal blast, and the other with a RC column under air blast, with a particular focus on the simulation sensitivity to the mesh size and the erosion criterion.

• Journal of KSNVE
• /
• v.2 no.3
• /
• pp.213-222
• /
• 1992

The effect of cavitation on the synchronous steady state response of a single rotor supported on cavitated squeeze film dampers executing a circular orbit is investigated theoretically. The Swift-Stieber boundary conditions and a long bearing approximation are utillized to evaluate the direct and the cross coupled damping coefficients of a cavitated squeeze film damper. For typical design parameters, frequency response curves are presented here to exhibit the effect of cavitation on the imbalance response and transmissibilities for both a flexible rotor and a rigid rotor. Investigations show that cavitation occured in a squeeze film damper produces bistable jump phenomena and deteriorates the performance of a squeeze film damper. This arises from that the large cavity causes substantial increment of the cross coupled damping which has radial stiffening effect. Furthermore, the large cavity causes the decrement of the direct damping which has pure damping effect. It is also observed that in the absence of cavitation, both rotor excursion amplitude and imbalance transmissibilities are very well damped.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.1
• /
• pp.46-52
• /
• 2013

Economic properties of an integrated wind power plant (WPP) and the demand response (DR) programs in the sample electricity market are studied. Time of use (TOU) and direct load control (DLC) are two of the DR programs that are applied in the system. The influences of these methods and the incentive payments by market operator's (MOs) with variable elasticity are studied. It is observed that DR with TOU and DLC programs together yields better revenue and energy saving for MOs.

• Structural Engineering and Mechanics
• /
• v.21 no.6
• /
• pp.621-634
• /
• 2005

A direct transfer substructure method is presented in this paper for analyzing the dynamic characteristics and the seismic random responses of a series reactor. This method combines the concept of FRF (frequency response function) and the transfer matrix algorithm with the substructure approach. The inner degrees of freedom of each substructure are eliminated in the process of reconstruction and the computation cost is reduced greatly. With the convenient solution procedure, the dynamic characteristics analysis of the structure is valid and efficient. Associated with the pseudo excitation algorithm, the direct transfer substructure method is applied to investigating the seismic random responses of the series reactor. The numerical results demonstrate that the presented method is efficient and practicable in engineering. Finally, a precise time integration method is employed in performing a time-history analysis on the series reactor under El Centro and Taft earthquake waves.

• Journal of the korean Society of Automotive Engineers
• /
• v.15 no.1
• /
• pp.81-88
• /
• 1993

A direct treatment of the min-max type objective function of the dynamic response optimization problem is proposed. Previously, the min-max type objective function was transformed to an artificial design variable and an additional point-wise state variable constraint function was imposed, which increased the complexity of the optimization problem. Especially, the design sensitivity analysis for the augmented Lagrangian functional with the suggested treatment is established by using the adjoint variable method and a computer program to implement the proposed algorithm is developed. The optimization result of the proposed treatment are obtained for three typical problems and compared with those of the previous treatment. It is concluded that the suggested treatment in much more efficient in the computational effort than the previous treatment with giving the similar optimal solutions.