• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.142-144
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• 2018

This paper discusses the development of semi-automatic search program for crown delineation in stand level. The crown of an individual tree was delineated by applying the Watershed (WS) and Valley Following (VF) algorithms. Unmanned Aerial Vehicle (UAV) images were used in the semi-automatic search program to delineate the crown area. The overall accuracy and Khat were used in accuracy assessment. WS algorithm's model showed the overall accuracy and Khat index of 0.80 and 0.59, respectively, in Plot 1. However, the overall accuracy and Khat of VF algorithm's model were 0.78 and 0.51, respectively, in Plot 2.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.658-663
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• 2002

Hall factor of electrons in $\Gamma$-valley is calculated as functions of temperature, impurity concentration, and nonparabolicity of conduction valleys by taking into account the current density obtained from the Boltzmann transport equation. The dependence of the Hall factor on the temperature is clearly shown in the case of the optical phonon scattering and that on the impurity concentration is obvious in the case of the ionized impurity scattering. As the nonparabolicity of the conduction band increases, the Hall factor due to the acoustic or optic phonon scattering increases, whereas that due to the ionized impurity scattering decreases. The change of the Hall factor can be analysed in terms of the dispersion of relaxation time.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.213-219
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• 2004

This paper proposes speaker recognition algorithm which includes the pitch parameter for the peak and valley. The time-frequency hybrid method for pitch extraction is valuable in that it can improve resolution in the time domain and accuracy in the frequency domain at the same time. It makes reference pattern using membership function and performs vocal track recognition of common character using fuzzy pattern matching in order to include time variation width for non-linear utterance for proposed method, speaker recognition experiments are carried out using vowels and number sounds.

• Journal of Power Electronics
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• v.12 no.2
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• pp.305-316
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• 2012

The paper presents an accurate loss model based controller of an induction motor to calculate the optimal air gap flux. The model includes copper losses, iron losses, harmonic losses, friction and windage losses, and stray losses. These losses are represented as a function of the air gap flux. By using the calculated optimal air gap flux compared with rated flux for speed sensorless indirect vector controlled induction motor, an improvement in motor efficiency is achieved. The motor speed performance is improved using a fuzzy logic speed controller instead of a PI controller. The fuzzy logic speed controller was simulated using the fuzzy control interface block of MATLAB/SIMULINK program. The control algorithm is experimentally tested within a PC under RTAI-Linux. The simulation and experimental results show the improvement in motor efficiency and speed performance.

• Mycobiology
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• v.34 no.4
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• pp.180-184
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• 2006

The mycobiota of 160 hair and nail samples collected from 4 different governorates in upper Egypt were estimated using soil plate method for isolating keratinophilic and dermatophytic fungi. Twenty-three fungi were recorded on both hair and nail samples collected from the four governorates. Highest fungal diversity (20) was collected from Red Sea samples followed by Qena (18) and Aswan (17) while lowest fungal diversity was recorded from Sohage samples. The common genera were Aphanoascus, Aspergillus, Penicillium, Paecilomyces and Chrysosporium. The most prevalent species belonging to these genera were: A. fulvescens, Aphanoascus sp. A. flavus link, A. flavus var. columnaris, P. chrysogenium. P. lilacinus and C. sulfureum. True dermatophytes such as Nannizzia fulva appeared in $20{\sim}30%$ of the male samples.

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.143-163
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• 1998

In order to clarify the depositional environment and sea-level change at Ilsan area including Gawaji and Saemal valley plains, which is located at the right side in downstream of the Han River, boring data, radiocabon dating and diatom analysis were comprehensively investigated. As a result, the palaeogeographies fo this area altered by the transgressions and regressions after 7,000 y. BP could be restored. The high tide sea-level(mean high water level of spring tide) was arrived ca. 7,000y. BP at the valley plain and risen to ca. 5.5m at ca. 5000y. BP. Since then, the sea-level was kept up the same level to ca. 3,200 BP. The descended sea-level to ca. 2,300 BP was risen up to ca. 5.8m in ca. 1,800 y. BP. It is presumed that such a sea-level change as well as the different sediments in quantity supplied from the river basin of the valley plain could be effected to change diversely the depositional environment of the study area and eventually to the prehistoric human life.

• Wind and Structures
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• v.7 no.1
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• pp.1-12
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• 2004

Numerical simulation of flow past two-dimensional hill and valley is presented. Application of three turbulence models - the standard and modified (Kato-Launder) $k-{\varepsilon}$ models and standard $k-{\omega}$ model - is discussed. The computational methodology is briefly described. The mean velocity and turbulence intensity profiles, obtained from numerical simulations of flow past the hill, are compared with the experimental data acquired in a boundary-layer wind tunnel at Colorado State University. The mean velocity, turbulence kinetic energy and Reynolds shear stress profiles from numerical simulations of flow past the valley are compared with published experimental data. Overall, the results of simulations employing the standard $k-{\varepsilon}$ model were found to be in a better agreement with the experimental data than those obtained using the modified $k-{\varepsilon}$ model and the $k-{\omega}$ model.

• Water for future
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• v.23 no.4
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• pp.459-466
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• 1990

In the Ice Valley, it freeze in summer season. However, there is no ice during winter. In order to clarify the phenomenon of unusual temperature, numerical experiments were conducted using the coupled equations of fluid flow and heat transfer. The results demonstrated that temperature inversion in the Ice Valley is primarily due to delay of the groundwater temperature. Also, the results of the simulation suggest that major factors affecting the delay are the topographical configuration, geological factors and groundwater flow system, combined with groundwater recharge and discharge systems.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.125-134
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• 1990

The purpose of this study is to assess the performance of Short-term atmospheric dispersion models --- ISCST, MPTER, VALLEY --- with terrain adjustment. The models are evaluated through correlation analysis, paired analysis and log-normal culmulative analysis between the measured and predicted concentrations in Samcheonpo area. The correlation coefficients between the measured and predicted concentrations turn out to be higher with terrain adjustment than those without terrain adjustment. In paired analysis, the mean differences and average absolute gross errors of concentrations do not change significantly with terrain adjustment. But the variances of the residuals become much smaller when the terrain is adjusted. Through the log-normal cumulative analysis, it is found that the terrain adjustment improve the prediction performance of MPTER and VALLEY, but do not affect significantly that of ISCST. Overall, it is concluded that the performance of short term atmospheric dispersion models improve when the terrain is considered in computation, especially in MPTER and VALLEY.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.109-114
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• 2012

In this paper, We studied LED(Light Emitted Diode) sensor lights system using PIR(Pyroelectric Infrared Ray) sensor, CdS and MCU(Micro Controller Unit). And applied the valley fill circuit to improve the power factor. We designed the amplifier for each sensor and the LED driver for constant current which is the buck converter. Also, we proposed the algorithm of LED control by each sensors using MCU. Experimental results showed that power factor is 92% with valley fill circuit.