• Geophysics and Geophysical Exploration
• /
• v.14 no.3
• /
• pp.214-219
• /
• 2011

We perform the frequency-domain waveform inversion based on the residual-selection strategy. In the residual-selection strategy, we classify time-domain residual wavefields into several groups according to the order of absolute amplitudes. Because the residual wavefields are normalized after regularization of the gradient directions within each group, the residual-selection strategy plays a role in enhancing the small-amplitude wavefields, which contributes to improving the deep parts of inverted subsurface images. After classifying residuals in the time domain, they are transformed to the frequency domain. Waveform inversion is performed in the frequency domain using the back-propagation technique which has been popularly used in reverse-time migration. The residual-selection strategy is applied to the SEG/EAGE salt and IFP Marmousi models. Numerical results show that the residual-selection strategy yields better results than the conventional frequency-domain waveform inversion.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.8
• /
• pp.558-565
• /
• 2019

A lot of studies on the survivability of missiles have been widely studied, since the technology of modern warships equipped with state-of-the-art defense systems has been improved. The survivability of missiles can be improved by attacking a target simultaneously using multiple missiles. For this reason, impact time control guidance (ITCG) laws have been widely studied. This paper deals with the effect of time-to-go estimate to ITCG laws. In this paper, two kinds of time-to-go estimate are first introduced in two-dimensional and three-dimensional environment and then ITCG laws are derived using the time-to-go estimate. Numerical simulations are performed to analyze the performance of the designed ITCG laws and the effect of time-to-go estimate is discussed.

• Tuberculosis and Respiratory Diseases
• /
• v.65 no.1
• /
• pp.7-14
• /
• 2008

Background: Residual pleural thickening (RPT) is the most frequent complication of tuberculous pleurisy (TP), and this can happen despite of administering adequate anti-tuberculous (TB) therapy. Yet there was no definite relation between RPT and other variables. The aim of this study was to examine matrix metalloproteinases (MMPs) and the inhibitors of metalloproteinases (TIMPs) and to identify the factors that can predict the occurrence of RPT. Methods: The patients with newly-detected pleural effusions were prospectively enrolled in this study from January 2004 to June 2005. The levels of MMP-1, -2, -8 and -9, and TIMP-1 and -2 were determined in the serum and pleural fluid by ELISA. The residual pleural thickness was measured at the completion of treatment and at the point of the final follow-up with the chest X-ray films. Results: The study included 39 patients with pleural fluid (PF). Twenty-three had tuberculous effusion, 7 had parapneumonic effusion, 7 had malignant effusion and 2 had transudates. For the 17 patients who completed the anti-TB treatment among the 23 patients with TP, 7 (41%) had RPT and 10 (59%) did not. The level of PF TIMP-1 in the patients with RPT ($41,405.9{\pm}9,737.3ng/mL$) was significantly higher than that of those patients without RPT ($29,134.9{\pm}8,801.8$) at the completion of treatment (p=0.032). In 13 patients who were followed-up until a mean of $8{\pm}5$ months after treatment, 2 (15%) had RPT and 11 (85%) did not. The level of PF TIMP-2 in the patients with RPT ($34.4{\pm}6.5ng/mL$) was lower than that of those patients without RPT ($44.4{\pm}15.5$) at the point of the final follow-up (p=0.038). Conclusion: The residual pleural thickening in TP might be related to the TIMP-1 and TIMP-2 levels in the pleural fluid.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.9
• /
• pp.55-63
• /
• 2014

Up to date, numerous studies on wireless sensor networks have been performed to overcome the Energy-Constraint of the sensor system. Existing schemes for estimating the residual energy have considered only voltage of sensor system. However battery performance in the real is affected by temperature and load. In this paper we introduce more accurate scheme, for the use in wireless sensor node, based on the interpolation of lookup tables which allow for temperature and load characteristics, as well as battery voltage.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.10
• /
• pp.870-877
• /
• 2014

Geostationary satellites undergo various orbital perturbations and this results in location change. Therefore, all the geostationary satellites use the thruster in order to control the location change. For this purpose, the suitable amount of liquid propellant is mounted and the amount of propellant is reduced as time goes by. This means that the lifetime of the satellite depends on the residual propellant amount. Therefore precise residual propellant gauging is very important for the mitigation of economic losses arised from premature removal of satellite from its orbit, satellites replacement planning, slot management and so on. In this paper, we introduce the propellant gauging methods used in the geostationary satellites and the propellant gauging method studied in the laboratory level.

• Proceedings of the KOSOMBE Conference
• /
• v.1994 no.12
• /
• pp.117-120
• /
• 1994

수술 전 간 기능이 저하되어 있는 간암환자의 경우 너무 많은 간 조직을 절제하면 남아있는 조직의 기능만으로는 생존하기 어려울 때가 있다 그러므로 수술전 간 기능의 평가를 정확히 할 수 있고 간절제 후에 잔여세포의 기능을 정확히 측정하는 것은 매우 중요한 의미를 갖게 된다. 현재의 일반적인 간 기능 검사나 Indocyanine 등을 이용하는 방법으로는 수술 후 잔여 간세포의 기능을 예측할 수 없다. 그리하여 본 연구에서는 수학적 deconvolution 방법을 이용하여 Hepatic extraction fraction(HEF)를 구하여 수술 후 잔여 간세포의 기능을 정량적으로 예측할 수 있는 software를 개발하고자 한다. 그리하여 간암 환자의 수술여부 및 절제부위의 크기를 결정할 수 있으며 또한 HEF로 신생아 황달의 원인인 간염과 간담도 폐쇄를 식별할 수 있다.

• Proceedings of the Korean Society of Grassland Science Conference
• /
• 1999.06a
• /
• pp.99.2-99
• /
• 1999

본 연구는 옥수수$\longrightarrow$ 연맥 작부조합에서 소액상분뇨의 시용수준을 달리하여 계속 시용구와 잔여효과구로 나누었을 때 작물의 생육특성, 총 건물 수량, N 회수율 및 토양특성 변화를 구명하고자 수행하였다. 수확당시 추파용 연맥의 평균초장은 계속시용구가 70.2cm인데 비해 잔여효과구는 61.4cm였으며, 계속시용구가 잔여효과구보다 CP 함량 1.0%, ADF 함량 1.6%, NDF 함량이 3.1% 높았다(P＜0.05).(중략)

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04a
• /
• pp.40-42
• /
• 2004

본 논문에서는 WDM 네트워크에서 보다 현실적인 파장 변환을 고려하면서 잔여링크를 최대화시킬 수 있는 파장 할당 알고리즘을 제시한다. 기존의 기법들은 각 노드들의 과장 변환 능력을 무시하고 전체 네트워크의 파장 변환 능력을 일률적으로 고정시킨 것을 가정하기 때문에 비효율적이라 할 수 있다. 제안된 기법은 각 노드의 파장 변환 능력을 각각 고려하면서 사용 가능한 잔여링크의 집합을 가능한 최대화 할 수 링(Ring)의 형태로 만든다. 이것은 잔여링크를 최대화하여 어떤 경로 요구가 있더라도 파장을 할당 할 수 있게 한다. 그렇기 때문에 네트워크에서의 블러킹 확률을 최대 19%까지 낮출 수 있었으며, 파장변환 횟수에서 대략 40%의 성능 향상을 보이고, 네트워크의 활용성을 높일 수 있음을 성능 비교를 통해서 볼 수 있다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.5 no.1
• /
• pp.60-68
• /
• 2001

Thermal Mass Method(TMM) and its accuracy, utilized in the propellant gauging system of KOREA SAT-3, are described in the paper The residual in the fuel tank system of KOREASAT-3 is simulated using TMM based on the KOREASAT-3 data package An accuracy of TMM is calculated using analytical method and compared with the error analysis Monte Carlo methods.

• Journal of the Korean Arthroscopy Society
• /
• v.15 no.2
• /
• pp.125-131
• /
• 2011

Optimal treatment of the torn posterior cruciate ligament (PCL) remains controversial. The type of tibial fixation (transtibial vs inlay), the femoral tunnel position within the femoral footprint (central, eccentric or isometric), and the number of bundles in the reconstruction (single-bundle vs double-bundle) are controversial issues. The PCL has a better chance of spontaneously healing than the anterior cruciate ligament (ACL) because of a rich blood supply (near the branch of the middle genicular artery) and coverage with a thicker synovium. In general, for easier passage of the graft and full visualization of the original ligament attachment site during the precise positioning of the tunnel, the remaining PCL fibers are usually debrided during reconstruction. However, the remaining remnant structures would significantly contribute to the posterior stability of the knee joint, the healing of the graft, preserving proprioceptive function of the mechanoreceptors in the PCL. Double bundle PCL reconstruction may result in some surgical complications because of increased complexity of making tunnel. Therefore, single bundle PCL reconstruction with remnant preservation seems to be an effective procedure.