• Journal of the Korean earth science society
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• v.38 no.6
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• pp.395-404
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• 2017

In this study, we classified observed fog events in the Middle Nakdong River near Gumi and analyzed the meteorological characteristics before and after the fog formation. The observation was performed from 2013 to 2015 using visibility meter. A total of 74 fog events were observed and most of them were classified as steam fog. The duration of observed steam fogs was longer than that of typical inland fogs because the nocturnal evaporation from the water surface was enhanced by the topographical characteristics. In order to analyze the effect of evaporation from the stream on the fog duration, the evaporation was estimated using the Penman-Monteith and the Bulk aerodynamic methods. The estimated evaporation by the Bulk method was similar to the actual evaporation from the water surface. Therefore, the Bulk method is suitable for estimating the evaporation from water surface. The evaporation amount, estimated by using the Bulk method was higher on fog days than non-fog days at 06 LST and 07 LST. The added evaporation of fog days released latent heat to the atmosphere and provided energy to maintain the turbulence in the fog. This phenomenon was confirmed by the increase of wind speed, temperature and turbulent kinetic energy within the fog.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.259-261
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• 1999

In this paper, we investigated the frequency dependences of AC loss and the magnetic properties of a superconductor using magnetization method. We used the YBCO bulk superconductor sample which has a square-shaped cross sectional area of $6mm{\times}6mm$. and 43mm-long in axial direction. The applied AC magnetic field was parallel to the direction of sample axis. It is observed that YBCO bulk has the diamagnetic properties. AC loss calculation of YBCO bulk superconductor was performed by evaluating the total area of magnetization traces. We performed two cases of experiments, one for $B_m<B_p$ and the other for $B_m<B_p$. The experiments showed that the AC loss dependences on frequency were different in each mode, as was indicated in other publications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.945-951
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• 2012

In this study, we analyze the static and dynamic characteristics of a bulk-cement trailer with a simpler structure that carries powders. The commercial software ANSYS is used to prepare a detailed three-dimensional model of the chassis frame and tank body that bear most of the load of a bulk-cement trailer for the finite element analysis. Modal analysis is conducted to examine the dynamic characteristics of the trailer body, and static analysis shows weak links in the structure. Finally, we propose a method to increase the strength of vulnerable areas and to reduce the weight of the trailer by applying the Taguchi method.

• Journal of the korean society of oceanography
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• v.38 no.4
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• pp.166-172
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• 2003

Multi­Sensor Core Logger (MSCL) is a useful system for logging the physical properties (compressional wave velocity, wet bulk density, fractional porosity, magnetic susceptibility and/or natural gamma radiation) of marine sediments through scanning of whole cores in a nondestructive fashion. But MSCL has a number of problems that can lead to spurious results depending on the various factors such as core slumping, gas expansion, mechanical stretching, and the thickness variation of core liner and sediment. For the verification of MSCL data, compressional wave velocity, wet bulk density, and porosity were measured on discrete samples by Hamilton Frame and Gravimetric method, respectively. Acoustic impedance was also calculated. Physical property data (velocity, wet bulk density, and impedance) logged by MSCL were slightly larger than those of discrete sample, and porosity is reverse. Average difference between MSCL and discrete sample at both sites is relatively small such as 22­24 m/s in velocity, $0.02­-0.08\;g/\textrm{cm}^3$ in wet bulk density, and 2.5­2.7% in porosity. The values also show systematic variation with sediment depth. A variety of factors are probably responsible for the differences including instrument error, various measurement method, sediment disturbance, and accuracy of calibration. Therefore, MSCL can be effectively used to collect physical property data with high resolution and quality, if the calibration is accurately completed.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.104-115
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• 1992

The present study was conducted to compare the relative efficiency of four different breeding methods in tobacco varietal development. A single Fl hybrid plant from cross of two flue-cured cultivars of Nicotiana tabacum L Bright Yellow 4(BY4) and NC95, was selfed. F2population above cross was screened for resistance against bacterial wilt caused by Pseudommonas solanacearum E.F.Smith under the naturally infested field conditions, and the 30 lines were developed from F2 individual plant by anther culture (ADH), maternal method utilizing Nicotiana afpicana (MDH), single- seed descent(SSD) and Bulk breeding method, respectively. All characters except content of total alkaloids of ADH and MDH which wore bred by haploid methods reduced more than that of lines bred by conventional methods(SSD & Bulk) : however, the yields were 8% lower than other lines. The total alkaloid content of ADH was higher than that of MDH, and yield was reduced about 4n even though the number of leaf was identical with the MDH. All other characters of ADH were also reduced significantly. In the lines bred by conventional methods, population developed by SSD showed significantly wider leaf width, shorter plant height, later days to flower, and lower in percent reducing sugar than those by Bulk. The populations derived from haploid method showed greater phenotypic variance and wider range of variation than conventionally developed ones. The results obtained indicate that selection will provide a significantly greater genetic gain for leaf number and leaf length in the ADU and MDH populations, and for plant height and days to flower in the SSD and Bulk populations.

• KIISE Transactions on Computing Practices
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• v.21 no.10
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• pp.631-638
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• 2015

Today, the demand for speech recognition systems in mobile environments is increasing rapidly. This paper proposes a novel method for Korean phoneme segmentation that is applicable to a phoneme based Korean speech recognition system. First, the input signal constitutes blocks of the same size. The proposed method is based on a volatility indicator calculated for each block of the input speech signal, and the bulk indicators calculated for each bulk in blocks, where a bulk is a set of adjacent samples that have the same sign as that of the primitive indicators for phoneme segmentation. The input signal vowels, voiced consonants, and voiceless consonants are sequentially recognized and the boundaries among phonemes are found using three devoted recognition algorithms that combine the two types of primitive indicators. The experimental results show that the proposed method can markedly reduce the error rate of the existing phoneme segmentation method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.66-69
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• 2002

In the ideal forming theory(1), which has been deviously developed as a direct method for optimizing forming process, material elements are required to deform following the minimum plastic work path (or the proportional true strain path). Besides the general theory(2,3), specific ideal forming theories have been developed for membrane sheet forming(4) as well as two-dimensional steady bulk forming(5-7). In this work, the ideal forming theory was successfully applied for non-steady bulk forming under the plane strain condition. Here, the shape change complying with the minimum plastic work path, was effectively described by developing a numerical code based on the characteristic method. Numerical results obtained for a specific industrial part also include the optimum pre-forming shape and its evolving shape change to the final shape as well as the boundary traction history.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1240-1241
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• 2008

Superconducting ceramics of YBaCuO was fabricated on SrTiO substrate by chemical fabrication method using fine powder of YBaCuO having diameter less than 1um. The pattern of the fabricated superconducting bulk was linear and the thickness of it can be controlled in the range of 50um. The structure of the surface of film by diffraction pattern and composition. The tape like YBaCuO bulk with width of 10mm was formed on substrate using similar method. Tape like film is expected to utilize as material of superconducting tape.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.213-232
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• 2009

This document was prepared to review and summarize the analytical methods for airborne and bulk asbestos. Basic principles, shortcomings and advantages for asbestos analytical instruments using phase contrast microscopy(PCM), polarized light microscopy(PLM), X-ray diffractometer (XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM) were reviewed. Both PCM and PLM are principal instrument for airborne and bulk asbestos analysis, respectively. If needed, analytical electron microscopy is employed to confirm asbestos identification. PCM is used originally for workplace airborne asbestos fiber and its application has been expanded to measure airborne fiber. Shortcoming of PCM is that it cannot differentiate true asbestos from non asbestos fiber form and its low resolution limit ($0.2{\sim}0.25{\mu}m$). The measurement of airborne asbestos fiber can be performed by EPA's Asbestos Hazard Emergency Response Act (AHERA) method, World Health Organization (WHO) method, International Standard Organization (ISO) 10312 method, Japan's Environmental Asbestos Monitoring method, and Standard method of Indoor Air Quality of Korea. The measurement of airborne asbestos fiber in workplace can be performed by National Institute for Occupational Safety and Health (NIOSH) 7400 method, NIOSH 7402 method, Occupational Safety and Health Administration (OSHA) ID-160 method, UK's Health and Safety Executive(HSE) Methods for the determination of hazardous substances (MDHS) 39/4 method and Korea Occupational Safety and Health Agency (KOSHA) CODE-A-1-2004 method of Korea. To analyze the bulk asbestos, stereo microscope (SM) and PLM is required by EPA -600/R-93/116 method. Most bulk asbestos can be identified by SM and PLM but one limitation of PLM is that it can not see very thin fiber (i.e., < $0.25{\mu}m$). Bulk asbestos analytical methods, including EPA-600/M4-82-020, EPA-600/R-93/116, OSHA ID-191, Laboratory approval program of New York were reviewed. Also, analytical methods for asbestos in soil, dust, water were briefly discussed. Analytical electron microscope, a transmission electron microscope equipped with selected area electron diffraction (SAED) and energy dispersive X-ray analyser(EDXA), has been known to be better to identify asbestiform than scanning electron microscope(SEM). Though there is no standard SEM procedures, SEM is known to be more suitable to analyze long, thin fiber and more cost-effective. Field emission scanning electron microscope (FE-SEM) imaging protocol was developed to identify asbestos fiber. Although many asbestos analytical methods are available, there is no method that can be applied to all type of samples. In order to detect asbestos with confidence, all advantages and disadvantages of each instrument and method for given sample should be considered.

• Explosives and Blasting
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• v.22 no.3
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• pp.65-70
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• 2004

Lately, the length of tunnel, the number of long-large tunnel over 3 lanes are steeply increased because of the request for high-speed and straight road. Therefore, the maximization of excavation efficiency is needed in tunnel construction. The sapaesan tunnel (4 lanes with the length of 4km) construction was delayed with environmental conflict far 2 years. For making-up delayed construction period, various new methods were adopted to improve excavation length, look-out and blasting efficiency. This study introduced bulk explosive which is new method in tunnel blasting and verified the efficiency of bulk explosive far long-large tunnel.