• Journal of Astronomy and Space Sciences
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• v.20 no.1
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• pp.11-20
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• 2003

A method for estimating the NORAD SGP4 atmospheric drag term from minimum osculating orbit states, i.e., two osculating orbits, is developed. The first osculating orbit state is converted into the NORAD TLE-type mean orbit state by iterative procedure. Then the converted TLE is propagated to the second orbit state using the SGP4 model with the incremental SGP4 drag term. The iterative orbit propagation procedure is finished when the difference of the two osculating semi-major axes between the propagated orbit and the given second orbit is minimized. In order to minimize the effect of the short-term variations of the osculating semi-major axis, the osculating argument of latitude of the second orbit is propagated to the same argument of latitude of the first orbit. The method is applied to the estimation of the NORAD-type TLE for the KOMPSAT-1 spacecraft. The SGP4 drag terms are estimated from both NORAD SGP4 orbit propagation and the numerical orbit propagation results. Variations of the estimated drag terms are analyzed for the KOMPSAT-1 satellite orbit determination results.

• Journal of Embryo Transfer
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• v.27 no.1
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• pp.45-50
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• 2012

The objective of this study is to estimate the effect of adding TES to LEY and FGE freezing extender for the sperm viability, acrosomal morphology and DNA fragmentation from miniature pig sperm, we evaluated sperm characteristics in TFGE, TLE and LEY with various thawing condition ($37^{\circ}C$ for 20 sec, 45 sec and $75^{\circ}C$ for 5 sec, respectively), and in different concentration of glycerol at 1%, 1.5%, 3%. The sperm viability and normal acrosome intact(NAI) in TFGE (Viability : $60.3{\pm}2.4$, NAI : $58.6{\pm}2.2%$), TLE ($61.3{\pm}2.4$, $62.2{\pm}2.2%$) extender significantly(p<0.05) increased than that in LEY ($50.2{\pm}2.4$, $54.5{\pm}2.2%$) extender thawed at $75^{\circ}C$ for 5 sec. According to the results from glycerol concentration, the viability and NAI of miniature pig sperm in 1.5% glycerol TLE ($66.1{\pm}3.2$, $66.2{\pm}1.0%$) was highest among the experimental groups. In accordance with this, DNA fragmentation rates was the lowest in TLE ($43.3{\pm}0.5%$) while that in LEY ($63.5{\pm}2.3%$) is the highest. Therefore, these results suggest that TLE extender method for freezing- thawing of miniature pig sperm increased the viability after thawing.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.40.3-41
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• 2009

인류가 위성을 발사하기 시작하면서 수많은 우주파편이 발생하게 되었고 이로 인하여 우주파편 환경은 날이 갈수록 심각해지고 있다. 우주공간을 비행하는 우주물체는 분쇄된 파편, 임무 관련 파편, rocket body 그리고 운용위성으로 구분된다. U.S. Space Surveillance Network에 따르면 10cm 이상 크기를 갖는 물체는 현재 13,000개가 넘는다고 알려지고 있고 질량만 해도 6,000톤이 넘는다. 이런 우주파편 환경으로 인하여 우주파편 간의 충돌, 우주파편과 운용위성 간의 충돌 또는 운용위성 간의 충돌에 대한 우려가 꾸준히 제기되어왔고, 불행하게도 2009년 2월 10일 Iridium 33과 Cosmos 2251 위성이 고도 790km 부근에서 충돌하여 1,300여개의 우주파편이 발생했다. 또한 2007년에 중국이 고도 860km 부근에서 750kg에 해당하는 자국의 위성(FY-1C)을 미사일로 격추시킴에 따라 2500여개의 우주파편이 발생하여 저궤도의 우주파편 환경을 더욱 심각하게 만들고 있다. 운용위성과 우주파편과의 충돌 가능성을 분석하기 위해서는 우주파편 및 위성의 궤도정보를 알아야 한다. 이를 위해서 NORAD(North American Aerospace Defense Command)에서 제공하는 TLE(Two Line Element)가 주로 이용된다. 하지만 관측 및 궤도 결정 특성상 수 km의 오차를 포함하므로 궤도정보의 공분산이 크다는 단점이 있으므로 충돌 분석을 수행하는데 있어 한계가 있다. 이 논문은 충돌분석 수행에 있어 TLE 정보만을 이용한 경우뿐만 아니라 정밀궤도와 TLE를 동시에 이용한 경우를 비교함으로써 충돌 불확실성의 해소방안을 제시할 계획이다.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.28-39
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• 1999

Purpose: We investigated the difference of glucose metabolism of medial and lateral temporal lobes of patients with temporal lobe epilepsy (TLE) utilizing quantitative comparison of regional metabolic activities using asymmetric index. Materials and Methods: We studied 19 pathologically proven mesial TLE and 25 lateral TLE patients. Lateral TLE patients were either normal on magnetic resonance imaging (cryptogenic: n=14) or had structural lesions (lesional: n= 11). Asymmetric index (ASI) was calculated as [(ipsilateral-contralateral)/(ipsilateral+contralateral)]${\times}200$. Results: ASI of medial and lateral lobes of mesial TLE was decreased ($-16.4{\pm}8.3$ and $-12.1{\pm}5.5$, respectively). In cryptogenic lateral TLE, ASI of lateral temporal lobe was decreased ($-11.8{\pm}4.7$), whereas that of medial temporal lobe was not decreased ($-4.6{\pm}6.3$). ASI of medial lobe of lesional lateral TLE was $-7.3{\pm}9.1$, which was significantly different from that of mesial TLE (p<0.05). Patients with lesional lateral TLE had evident metabolic defects or decrease (ASI: $-22{\pm}10.5$) in lateral temporal lobe. While we could not find the difference of metabolic activity in lateral temporal lobes between cryptogenic lateral TLE and mesial TLE patients, the difference of metabolic activity was significant in medial temporal lobes which was revealed by ASI quantitation. Conclusion: Asymmetric decrease of metabolic activity in both medial and lateral temporal lobes indicates medial temporal epilepsy. Symmetry of metabolic activity in medial temporal lobe combined with asymmetry of that in lateral temporal lobe may give hints that the epileptogenic zone is lateral.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.83-90
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• 2014

The main purpose of this study is to estimate the effect of adding Tea-N-Tris (TES) to the freezing buffer for miniature pig sperm. In particular, we attempted to identify the association between the MMPs expression and the fertility and viability of frozen sperm from each extender (LEY (Lactose Egg-Yolk), TLE (TES + LEY), TFGE (TES + Fructose + Glucose Egg-Yolk)). In accordance with this, Hypoosmotic Swelling Test (HOST) respond test was the lowest among sperms frozen in LEY while the highest HOST respond was observed among sperms frozen in TLE. Furthermore, we observed MMPs expression in all sperm groups, with pro-MMP showing lower expression than active MMPs. The expression of MMP-9 and MMP-2 was the highest in sperms frozen in LEY, Meanwhile, sperms from the TFGE and TLE group showed lower level of MMP-9 and MMP-2 expression in the order of TLE being the lowest. LEY group showed lower rate of blastocyst development than the TES supplement group, although the difference was not statistically significant. Meanwhile the rate of blastocyst development appeared similar when sperms from TLE and TFGE group were used for IVF. Together, these results indicate that adding Tea-N-Tris to the sperm freezing buffer only suppresses MMPs protein activation but also maximize in-vitro fertility, providing a means to improve the success rate in the in vitro manipulation of miniature pig sperm.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.17-25
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• 2010

Objective: The focus of this study is brain plasticity associated with semantic aspects of language function in patients with medial temporal lobe epilepsy (mTLE) Methods: Using longitudinal functional magnetic resonance imaging (fMRI), patterns of brain activation were observed in twelve left and seven right unilateral mTLE patients during a word-generation task relative to a pseudo-word reading task before and after anterior temporal section surgery. Results: No differences were observed in precentral activations in patients relative to normal controls (n = 12), and surgery did not alter the phonological-associated activations. The two mTLE patient groups showed left inferior prefrontal activations associated with semantic processing (word-generation>pseudo-word reading), as did control subjects. The amount of semantic-associated activation in the left inferior prefrontal region was negatively correlated with epilepsy duration in both patient groups. Following temporal resection, semantic-specific activations in inferior prefrontal region became more bilateral in left mTLE patients, but more left-lateralized in right mTLE patients. The longer the duration of epilepsy in the patients, the larger the increase in the left inferior prefrontal semantic-associated activation after surgery in both patient groups. Semantic activation of the intact hippocampus, which had been negatively correlated with seizure frequency, normalized after the epileptic side was removed. Conclusion: These results indicate alternation of semantic language network related to recruitment of left inferior prefrontal cortex and functional recovery of the hippocampus contralateral to the epileptogenic side, suggesting an intra- and inter-hemispheric reorganization following surgery.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.335-337
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• 2002

The aim of this study was investigate the epileptogenic zone in temporal lobe epilepsy (TLE). We evaluated the subtraction image of interictal SPECT from ictal SPECT coregistered to 3-dimensional (3D) MRI, and compared with the normal healthy SPECT using a SPM99. Forty-nine patients with TLE (M:F=28:21, mean age: 33${\pm}$2.1 years) underwent a pairs of ictal and interictal SPECT. We performed subtraction interictal SPECT from ictal SPECT in TLE patients. In addition, using SPM methods and t-statistics, SPECT images of the TLE patients were compared with normal healthy SPECT on a voxel by voxel basis. The voxels with a p-value of less than 0.05, 0.005, 0.001 were considered to be significantly different. The subtraction results by ictal and interictal SPECT coincided with the significant rCBF changes when compare of the normal healthy SPECT using a SPM99. The results suggested that analysis of difference of the two methods using healthy normal SPECT with SPM99 is useful tool in evaluation of seizure focus in epilepsy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.270-278
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• 2014

This paper describes an improvement of space objects orbit prediction. To screen possible collisions between operational satellites and space objects, the TLE (Two-Line Element) was used as pseudo-measurement and than the orbit determination and orbit prediction were performed through the flight dynamics system. For determining the orbits, the state vectors were assumed by a series of TLEs within a certain period. The propagation error was analyzed according to the fitting period and a number of pseudo-observations. In order to find out the improvement of orbit prediction with the proposed method, KOMPSAT-2, 3 having the precise orbit in the meter-level range were first applied. Then the result applied to space objects under the same conditions was analyzed. As a result of the RMS error comparison with the orbit prediction of space object, the precision of orbit prediction was improved by approximately 90% for seven days prediction. The improved orbit prediction of space objects can be utilized in the daily analysis for initial screening of the close space objects at high risk.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.30-40
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• 2004

Purpose: The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron omission tomography (FDG PET). Materials and Methods: MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was peformed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Results: Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Conclusions: Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.261-265
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• 1992

To improve preservation and utilization of radish juice concentrates, radish juice were concentrated by reverse osmosis(RO) and thin layer evaporator(TLE) and their rheological properties were investigated. Radish juice concentrates were considered as nowtonian fluids. The apparent viscosity of conc. 1 (Heat treatment radish juice, concentrated by TLE), conc. 2 (Raw radish juice, concentrated by TLE), conc. 3 (Heat treatment radish juice, concentrated by RO) were 0.0503, 0.0578 and 0.0655 Pa.s at 10(1/s), respectively. The yield stress of these concentrates were ranged from 0.0001 to 0.0580 Pa. The activation energy for the flow of the radish juice conc. 1 were increased from 2.7057 to $4.1159{\times}10^4KJ/kg.mol$ by increasing concentration of radish juice.