• The Journal of the Acoustical Society of Korea
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• v.35 no.1
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• pp.35-41
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• 2016

Based on correlation and least square method, a closed-form algorithm for estimating the location of mixed far-field and near-field source is presented using the Uniform Circular Array (UCA). Recently, for a homogeneous circular arrangement case, a correlation based closed-form algorithm is proposed to estimate 2-D angle (azimuth, elevation) and the extended algorithm is proposed to 3-D location (azimuth, elevation, range). These algorithms assume the far-field source or near-field source only. Therefore, for mixed source localization, the proposed algorithm estimates source location with the assumption of far-field source, and then estimates the range to distinguish the far-field from the near-field source. For both cases, numerical experiments have been performed, which confirmed the validity of the proposed algorithm.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.633-645
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• 2006

The sheet metal stamping process continues to be a challenge to the field of science and engineering. The focus of this paper is to gain a better understanding of the sheet metal stamping process. By using Finite Element analysis and Design of Experiments, we are trying to analyze the stamping variables and determine which ones influence the stamping operations most.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.630-633
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• 2006

In this study, we concerned the steel cap and head part arrangement of PHC pile structure to complement existing construction process which have the defects such as highly hazardous circumstance for safety concerns and retard a term of works. The steel cap developed for supplement the stiffness between extend foundation and contact section of PHC pile that is based on structural theory. The experiments have been performed to evaluate the characteristics of behavior between head part of PHC pile using steel cap and extend foundation.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.65.3-65.3
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• 2017

With the advent of high energy/power lasers, extreme conditions, such as those found in astrophysical environments, can be reproduced in laboratory. The scaling between laboratory and astrophysical environments, especially for viscosity and resistivity that govern dissipation processes, is not perfect. Yet, the similarity is close enough to make laboratory experiments relevant for astrophysics. The results have been encouraging, in the sense of suggesting the possibility of exploring fundamental physical processes at play in astrophysical phenomena. In this talk, I will review a few successfully performed and ongoing experiments, such as those for turbulence and magnetic field generation in fluid regime and collisionless shock wave in plasma regime.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.663-667
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• 1999

In this paper, we review the conventional speaker verification algorithm and present the text-dependent speaker verification system for application over telephone lines and its result of experiments. We apply blind-segmentation algorithm which segments speech into sub-word unit without linguistic information to the speaker verification system for training speaker model effectively with limited enrollment data. And the World-mode] that is created from PBW DB for score normalization is used. The experiments are presented in implemented system using database, which were constructed to simulate field test, and are shown 3.3% EER.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.45-52
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• 1993

Evaluation of structural stability of aged wharf structure of pier type is of great importance for both safety and rehabilitation, Series of field dynamic experiments were performed for berthing impact and the results were used to calibrate analysis model. Through dynamic analysis for design, berthing impact safety of old wharf structure were evaluated. In this paper the procedure and results of experiments and analysis are presented.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.119-126
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• 2002

Recently, the flux community in Korea established a new regional flux network, so-called KoFlux, which will provide an infrastructure for collecting, synthesizing, and analysing long-term measurements of energy and mass exchange between the atmosphere and the various vegetated surfaces. KoFlux requires the collection of long time series of raw data, and a large amount of data are expected to accumulate due to continuous flux observations at each KoFlux sites. Therefore, we need a systematic and efficient tool to manage these raw data. As a part of this effort, a computer program far processing raw data measured from micrometeorological field experiments was developed for the flux community in Korea. In this paper, we introduce this program for processing raw data to estimate fluxes and other turbulent statistics and explain the micrometeolological processes coded in this data-processing program. Also, we show some examples on how to run the program and handle the outputs for the unique purpose of research interest.

• Journal of Ecology and Environment
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• v.41 no.8
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• pp.202-212
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• 2017

Background: To reveal establishment strategy of Sparganium erectum, we tried to find realized niche of adults through field survey and effects of water level on the establishment process through mesocosm experiments. Results: In the field survey, the height and coverage of community living in deeper water were greater than those of community living in shallow water. There was no statistically significant difference (p > 0.05) in the means of water and soil properties between the two communities. In mesocosm experiments, we found no correlation between water levels and germination rates, but S. erectum seedlings have characteristics of post germination seedling buoyancy when S. erectum seeds germinated in inundation conditions. Shoot height, total leaf length, and survival rates of sinking seedlings in shallow water levels at -5, 0, and 5 cm were higher than those in deeper water levels at 10 and 20 cm. Floating seedlings established in water levels of 3 and 6 cm only. The seedlings could live up to 6 weeks in floating state but died if they were unable to establish. Conclusions: The water level around adult S. erectum communities in the field were different from the water level at which S. erectum seedlings can survive in the mesocosm experiments. The findings provided not only understanding of S. erectum habitat characteristics but also evidence to connect historical links between the early seedlings stage and adult habitat conditions. We suggested the logical establishment strategy of S. erectum based on the data.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.334-334
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• 2017

Unstable soil moisture conditions often negatively affect the emergence, seedling establishment, and growth uniformity at the initial stage, and then reduce the grain yield and biomass in direct seeding cultivation for rice in rainfed fields. Therefore it is important to develop a technique to increase the rapid and stabilized seedling establishment and improve the uniformity of initial growth after sowing. This study aims to confirm results on seed priming effect of indoor using petri dish experiments can be reproduced in the field using container at Ghana. Twenty-seven rice varieties including of Oryza sativa L. and O. glaberrima Steud. were used in this study. The experiments using petri dish and container with different soil moisture conditions (5%, 10%, 15%, 20%) were compared. As a result, a significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and emergence time uniformity in the primed seed of container in 10% and 15% soil moisture condition. A significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and plant height in the primed seed of container in 10% soil moisture condition in O. glaberrima. This study concluded that the priming effect in petri dish demonstrate those in container in the field condition of Ghana in 10% and 15% soil moisture condition during seedling stage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.53-53
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• 2017

Unstable soil moisture conditions often negatively affect the emergence, seedling establishment, and growth uniformity at the initial stage, and then reduce the grain yield and biomass in direct seeding cultivation for rice in rainfed fields. Therefore it is important to develop a technique to increase the rapid and stabilized seedling establishment and improve the uniformity of initial growth after sowing. This study aims to confirm results on seed priming effect of indoor using petri dish experiments can be reproduced in the field using container at Ghana. Twenty-seven rice varieties including of Oryza sativa L. and O. glaberrima Steud. were used in this study. The experiments using petri dish and container with different soil moisture conditions (5%, 10%, 15%, 20%) were compared. As a result, a significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and emergence time uniformity in the primed seed of container in 10% and 15% soil moisture condition. A significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and plant height in the primed seed of container in 10% soil moisture condition in O. glaberrima. This study concluded that the priming effect in petri dish demonstrate those in container in the field condition of Ghana in 10% and 15% soil moisture condition during seedling stage.