• Journal of Astronomy and Space Sciences
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• v.28 no.4
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• pp.299-304
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• 2011

As more satellites are designed to downlink their observed image data through the X-band frequency band, it is inevitable that the occupied bandwidth of a target satellite will overlap with that of other X-band downlink satellites. For sun-synchronized low earth orbit satellites, in particular, it can be expected that two or more satellites be placed within the looking angle of a ground station antenna at the same time. Due to the overlapping in the frequency band, signals transmitted from the adjacent satellites act as interferers, leading to degraded link performance between target satellite and ground station. In this paper, link analysis was initiated by modeling the radiation pattern of ground station antenna through a validated Jet Propulsion Laboratory peak envelope model. From the relative antenna gain depending on the offset angle from center axis of maximum antenna directivity, the ratio of received interference signal level to the target signal level was calculated. As a result, it was found that the degradation increased when the offset angle was within the first point of radiation pattern. For a 7.3 m antenna, serious link degradation began at an offset angle of 0.4 degrees. From this analysis, the link performance of the coming satellite passes can be recognized, which is helpful to establish an operating procedure that will prevent the ground station from receiving corrupted image data in the event of a degraded link.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.45-59
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• 2002

This study is objected to demonstrate the spatial variability of the ground-water recharge by classifying the types of ground-water hydrographs and assessing the recharge ratio(the ratio of the rise of ground-water level to cumulative precipitation) of each type using the National Ground-water Monitoring network data. A total of 5 types were identified by factor analysis on the ground-water hydrographs nationwide. The recharge ratio of each type were estimated to be 6.5% (TYPE I), 4.1 % (TYPE II), 9.2%(TYPE III), 5.8 %(TYPE IV), 15.3 %(TYPE V) in the confidence level of 95.44% and 6% variation was estimated site by site even in the same type. The recharges of Han, Nakdong, Keum, Youngsan·Seomjin river basins were estimated as 10.0 %, 6.1 %, 8.3 %. and 6.6 % respectively. These results were consistent with the results of the existing baseflow method.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.393-399
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• 2020

In this study, the subsidence behavior caused by groundwater ex-flow in a limestone cavity encountered during tunnel excavation was quantified based on numerical analysis and the effect was analyzed. Based on the groundwater level and surface subsidence surveyed at the site, a numerical analysis technique was applied to analyze the characteristics of the subsidence behavior according to the tunnel passage of the geological vulnerabilities. The results of groundwater seepage-coupled analysis were analyzed to reflect the actual ground subsidence behavior. As a result of the study, it was analyzed that the ground subsidence due to the tunnel excavation in the limestone common section(the geological vulnerable zone) was analyzed that the dramatical decrease in groundwater level was the main cause. As a result of numerical analysis, it was analyzed that the long-term cumulative settlement of the asphalt surface after the groundwater ex-flow was 76~118mm due to the reduction of the volume of the soil layer due to the decrease in the groundwater level, and the settlement amount increased as the depth of the soil layer increased.

• Tunnel and Underground Space
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• v.27 no.4
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• pp.205-216
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• 2017

Fluctuations in groundwater level are the major cause of ground subsidence in the abandoned limestone mine. In this study, evaluation of groundwater flow under three different cases of natural condition, aggregate-filling, temporary drainage in groundwater-saturated limestone mine cavities was executed by 3-dimensional analysis. In the case of aggregate-filling, although the water level both in the upper ground of mine cavities and an agricultural watershed was elevated, it was lower than the water level fluctuation of an agricultural water use and rainfall and the flow rate was similar to the flow rate of natural condition. In the case of temporary drainage, as the water level in the upper ground of mine cavities and an agricultural watershed decrease rapidly and the flow rate has increased by 25times, so the risk of ground subsidence increased.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.5-13
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• 2012

In this study, the degrees of consolidation were evaluated by analyzing the long-term settlement measured at the 3 work sites with soft ground in Gyeongnam Area. The Hyperbolic, Hoshino and Asaoka method were used, which were focused on prediction of long-term settlement of land on the basis of field measurement data. And the applicability of the settlement prediction method according to the measurement periods was investigated by analyzing the degree of consolidation at the target areas after dividing the terms into early and latter parts. According to the results obtained at the early stage of consolidation, the Hyperbolic method appeared to be in the highest applicability level, which was followed by Asaoka and Hoshino method in the order of level. In the case of latter stage of consolidation, Asaoka method appeared to be in the highest applicability level, which was followed by and the Hyperbolic, Hoshino method in the order of level.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1246-1252
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• 2018

This study was conducted to investigate the effects of the addition levels of a phosphate replacer blend in ground pork sausages. The phosphate replacer consisted of 0.2% oyster shell calcium powder, 0.3% egg shell calcium powder, and 0.25% whey protein concentrate. Depending on the presence or absence of synthetic phosphate and the addition level of phosphate replacer, the following products were processed: control (+) (0.3% phosphate), control (-) (non-phosphate), 20AL (20% replacer), 40AL (40% replacer), 60AL (60% replacer), 80AL (80% replacer), and 100AL (100% replacer). The pH values of pork sausages increased (p<0.05) with increasing addition level of the phosphate replacer. When more than 40% of the phosphate replacer was added to pork samples (40AL, 60AL, 80AL, and 100AL), cooking loss was significantly reduced compared to both the control (+) and control (-). However, no significant differences were observed in the moisture content and CIE $L^*$ values between the controls and the treatments with a phosphate replacer. The control (+) and 100AL treatment had the highest (p<0.05) hardness, but the samples with the phosphate replacer were not significantly different in cohesiveness and springiness from the control (+). As addition level increased, the gumminess and chewiness of the products with the phosphate replacer increased, which were lower than those of the control (+). Therefore, more than 40% of a phosphate replacer may possibly substitute synthetic phosphate to improve product yields in ground pork sausages, although further studies may be needed for improving the textural properties of the final products.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.688-696
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• 2003

The casing oscillator used for basic construction of buildings, factories and bridges is a construction machine, which rotates and rolls the casing to insert it into the ground. It is very important that the casing is positioned perpendicular to the sea level regardless of the slope of the ground. In this paper, we present a new casing oscillator that doesn't need additional work to level the ground for the casing insertion. The kinematic analysis fur work space of a casing oscillator is presented and carried out with auto-balancing of the casing oscillator using posture feedback control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.442-445
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• 2002

The casing oscillator used for the foundation work in the construction place. Construction machinery which makes the casing rotate and roll can insert the casing in the ground. It is very important to make the casing perpendicular to sea level regardless of slope of ground. So in this paper, we present the new type casing oscillator that need not to level the ground for the work of casing insertion. The inverse kinematics analysis for the real-time control of casing oscillator is presented.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.404-415
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• 2010

In this paper, using the TDR sensors, variation of soil water content changes were measured as TDR data. Then filtering technique was determined using Fourier transform. Determine the moisture content of soil and ground water level and tried to determine unsaturated zone. First, variation of water content changes were measured TDR data by indoor experiment. Then as a function of TDR data made for water content of soil. Next, through Acrylic indoor laboratory model experiments, changes in ground water levels and lateral penetration of the field conditions were reproduced in an indoor. Field applicability of the TDR sensor was demonstrated by analysis of this. TDR sensor was installed in the embankment, TDR data were measured by TDR sensor.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.436-439
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• 2007

This paper describes the optimization of PGS(Patterned Ground Shield) of 5.5 turns rectangular spiral inductor using Taguchi's method. PGS is decrease method of parasite component by silicon substrate among dielectric loss reduction method. By using the taguchi's method, each parameter is fixed upon that PGS high poison(A), slot spacing(B), strip width(C) and overlap turn number(D) of PGS design parameter. Then we verified that percentage contribution and design sensitivity analysis of each parameter and level by signal to noise ratio of larger-the-better type. We consider percentage contribution and design sensitivity of each parameter and level, and then verify that model of optimization for PGS is lower inductance decreasing ratio and higher Q-factor increasing ratio by EM simulation.