• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.57-60
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• 1997

The properties of Low-heat cement are especially in lower heat of hydration than that of other types of cement. In other respect, Low-heat concrete is more advantageous than OPC concrete in chemical resistance, long term age compressive strength, slump loss and resistance to seawater. This paper deals with 28 days age compressive strength and slump loss by elapsed time of mortar and concrete that made with Low-heat cement and 3 types of other cement.

• Communications of the Korean Mathematical Society
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• v.14 no.4
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• pp.805-814
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• 1999

We consider an MMPP/G/1/K finite queue with two-level threshold overload control. This model has frequently arisen in the design of the integrated communication systems which support a wide range applications having various Quality of Service(QoS) requirements. Through the supplementary variable method, se derive the queue length distribution.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.433-438
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• 1997

The freshness of apple was evaluated by characterizing the surface texture of flesh cells. The freshness index which was related to the amount of wrinkles on the cell surface was defined to quantify the freshness. Four parameters relevant to the amount of the cell wrinkles were selected and measured using image analysis including wrinkle extraction procedure and Fast Fourier Transform of a wrinkle-extracted image. Out of 4 parameters, three parameters had highly significant correlations with the time elapsed after harvest. But it was concluded that two parameters out of such 3 parameters could be used for description of freshness index.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.7-12
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• 1992

The aim of this study is to develop economical High-Strength and High-Quality Concrete, and to assure quality control of Concrete in the field. For this purpose, Five types of Mixing Methods are examined and the relationship between slump loss and slump recovery by transport is studied. As a result, workability and strength are dependent on the Mixing Method, although the Mixing proportions are same, Also, adding admixture in the field is proposed as an alternative to consider the relationship between slump loss and slump recovery.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.368-370
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• 1998

The TPS accepts as input, vehicle parameters, control parameters, station parameters and right-of-way profile. Outputs of TPS program include velocity, elapsed time and power profiles. This paper represents how to develop the TPS program. The TPS program simulates the operation of a single train under the input conditions.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.359-362
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• 2002

In this paper, we propose a structure of 800bps high speed router and a gigabit Ethernet line interface board. Having Programmability, network processor is applied to gjgabit Ethernet line interface board. Also, we propose a new method to upgrade image files that consist of operating system and drivers. It is possible to upgrade image files for several boards at once and to reduce the elapsed time for image upgrade using tile proposed method.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.359-364
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• 2013

This study was conducted to develop a model to estimate crop leaf surface temperature. The results were as following; A definition for the daily time based on elapsed time from the midnight (00:00) as "E&E time" with the unit of Kmin. was suggested. The model to estimate the scaled temperature ($T^*e$) of crop leaf surface temperature by scale factor ($T^*$) according to the "E&E time : Kmin."(X) was developed as eq. (1) $T^*e=0.5{\cdot}sin(X+780)+0.5$ (2) $T^*=(Tx-Tn)/(Tm-Tn)$, Tx : Daily leaf temperature, Tm : Daily maximum leaf temperature, Tn : Daily minimum leaf temperature. Relative sensitivity of the measured temperature compared to the estimated temperature of red pepper, soybean and persimmon was 1.078, 1.033 and 0.973, respectively.

• Agricultural and Biosystems Engineering
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• v.1 no.1
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• pp.38-42
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• 2000

Though the freshness for agricultural products is an important factor related to their quality management, this terminology is being used restrictedly because it is very subjective. In this study, a dimensionless index which had the span of the maximum of 1 through the minimum of 0 was proposed to describe freshness of the product with time-variant quality and was applied to Tsugaru and Fuji apples. First, the compressive properties having the linearity in their change regarding time elapsed after harvest were selected. For Tsugaru apple, bio-yield and rupture forces had high correlation with time while for Fuji, bio-yield and rupture deformations had high correlations. When the slope, or ratio of force to deformation, was considered, the effect of cultivar could be neglected. When the linearly time-variant compressive properties for Tsugaru and Fuji apples were involved in the freshness indices, they described well freshness of apples. Also, the freshness decay constant depicted a characteristic which related to freshness decay rate. Therefore, the freshness index can be utilized to manage the quality during storage and distribution of apples.

• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.91-107
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• 1996

We determine analytically the onset of thin-shell formation time of fast wind bubble with power-law energy injection $E_{in}=E_0t^s$, and power-law ambient density structure, ${\rho}_0(r)={\bar{\rho}}(r/{\bar{r}})^{-{\omega}}$. Thin-shell formation time, $t_{sf}$ can be estimated by minimizing the total time elapsed before the complete cooling of shocked gas. For uniform medium (${\omega}=0$) and constant energy injection (s = 1), the onset of shell formation is found to be at $t_{sf}=5.2{\times}10^3yr$, which agrees Quite well with the results of FCT 1D numerical calculation. We solve the line transfer problem with previous result derived by numerical calculation in order to calculate line profile of [OIII] (${\lambda}=5007{\AA}$) forbidden line. In general, radiative outer shell causes the formation of double peaked line profile. Each peak corresponds to approaching and receeding shells with large velocities. Our line profiles show good agreements with observation of expanding shell structure.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.77-81
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• 1980

The author has studied comparatively the sealing quality of conventional Z.O.E. cement, Kerr sealer and Nogenol sealer by means of penetration of 2% methylene blue solution through the root apex of human teeth in 72 cases as time elapsed. The results were as follows; 1. All the specimens, whose dye immersion time is two days, showed dye penetration of low degree unrelated to the kinds of root canal sealer. 2. Kerr sealer group, like conventional Z.O.E. group, showed dye penetration of high degree related to increased time of immersion in the dye. 3. In Nogenol group, there was slight increase in penetration related to increased time of immersion in the dye. 4. Kerr sealer group showed comparatively lower grade of dye penetration than conventional Z.O.E. and higher than Nogenel sealer.