• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.11a
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• pp.183-184
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• 2008

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.163-164
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• 1998

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.10a
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• pp.347-348
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• 2017

• Speech Sciences
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• v.9 no.3
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• pp.35-45
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• 2002

A simple algorithm for discriminating voiced sounds in a speech is proposed. In addition to low-frequency energy and zero-crossing rate (ZCR), both of which have been widely used in the past for identifying voiced sounds, the proposed algorithm incorporates pitch variation to improve the discrimination rate. Based on TIMIT corpus, evaluation result shows an improvement of 13% in the discrimination of voiced phonemes over that of the traditional algorithm using only energy and ZCR.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.677-679
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• 2013

• Journal of Korea Water Resources Association
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• v.55 no.spc1
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• pp.1223-1234
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• 2022

Efforts for reducing greenhouse gas emission coping with climate change have also been performed in the field of water and wastewater works. In particular, the technical development for reducing energy has been applied in operating water distribution system. The reduction of energy in water distribution system can be achieved by reducing structural loss induced by topographic variation and operational loss induced by leakage and friction. However, both analytical and numerical approaches for analyzing energy budget of water distribution system has been challengeable because energy components are affected by the complex interaction of affecting factors. This research drew mathematical equations for 5 types of state (hypothetical, ideal, leak-included ideal, leak-excluded real, and real), which depend on the assumptions of topographic variation, leakage, and friction. Furthermore, the derived equations are schematically illustrated and applied into simple water network. The suggested method makes water utilities quantify, classify, and evaluate the energy of water distribution system.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.1
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• pp.15-20
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• 2015

In this study, the optimization and performance characteristics of a cascade heat pump system was analyzed with the variation of low stage refrigerant charge amount. The cascade heat pump was designed and constructed with R134a and R410A as the refrigerant for high stage and low stage cycle, respectively. Experiments were conducted by varying the low stage charge amount and the performance characteristics of the cascade heat pump were studied. The refrigerant charge amount of the low stage cycle was varied between the ranges of -15% and +10% of the optimum charge amount. The performance variation experienced in the cascade heat pump due to the variation of refrigerant charge amount shows greater effect in the undercharge regions than the overcharge regions. COP reduction in the undercharge region is larger than the decrease in the overcharge region. Some cycle variation such as power consumption and cycle pressure according to low stage refrigerant charge amount showed different trends comparing with those according to high stage refrrgerant charge amount. Therefore, the optimum charge amount of the cascade heat pump should be determined based on the experimental data obtained by the variation of high and low stage refrigerant charge amount.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.782-788
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• 2014

Wind power generation has been viewed as a promising renewable energy to meet challenge of climate change. However, wind power is susceptible to climate change because previous investigation shows there are declining trends of the land surface wind speeds over middle and lower latitudes. Since long term variation trends is notably different from inter-annual random variation and could have notable impact on wind farm from planning perspective, observed meteorological data of Taiwan is investigated to find out long term variation trends of wind speed and its impact on wind power generation. It is discovered that wind speed in majority of stations in west coast of Taiwan have ascending trends while that of all investigated stations in east coast have descending trends. Since east of Taiwan is not suitable for wind power development for its higher likelihood suffering Typhoons and most of established wind farm locate in west coast of Taiwan, it is speculated that long term variation trend of wind do not have notable negative impact on wind power generation in Taiwan.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.19-22
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• 2018

The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

• International Journal of Oral Biology
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• v.34 no.2
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• pp.49-52
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• 2009

Perception of sweet compounds is important for animals to detect external carbohydrate source of calories and plays a crucial role in feeding behavior of animals. Recent progress in molecular genetic studies provides evidence for a candidate receptor (heterodimers with taste receptor type 1 member 2 and 3: T1R2/T1R3), and major downstream transduction molecules required for sweet taste signaling. Several studies demonstrated that the sweet taste signal can be modulated by a satiety hormone, leptin, through its receptors expressed in a subset of sweet-sensitive taste cells. Increase of internal energy storage in the adipose tissue leads to increase in the plasma leptin level which can reduce activities of sweet-sensitive cells. In human, thus, diurnal variation of plasma leptin level parallels variation of taste recognition thresholds for sweet compounds. This leptin modulation of sweet taste sensitivity may influence individuals' preference, ingestive behavior, and absorption of nutrients, thereby plays important roles in regulation of energy homeostasis.