• Advances in nano research
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• v.10 no.5
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• pp.461-470
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• 2021

Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G₂ was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, ¹H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G₂-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, ¹H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G₂-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.20-20
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• 2017

궤도형 차량의 이동구조는 에너지 소비 측면에서 단점이 있지만 접지압의 감소로 인한 평지 및 야지험지에서도 원활한 주행이 가능한 장점으로 인해 농업분야의 플랫폼에서 많이 사용된다. 곡식을 베는 일과 탈곡하는 일을 한 번에 하는 콤바인도 이러한 무한궤도형 이동구조를 사용한다. 또한 궤도형 차량의 방향전환 및 주행속도 변환은 좌 우 궤도의 회전 속도를 다르게 하여 동시에 제어하기 때문에 정교한 주행 성능을 위해서는 궤도형 차량의 기구학 모델을 고려한 경로 계획이 필요하다. 본 연구에서는 직교형 포장에서 Round harvesting 기법 기반으로 궤도형 차량의 기구학 모델 및 포장정보를 고려한 자율주행 콤바인 경로계획 알고리즘을 개발하고자 하였다. 이를 위해 Labview 기반의 궤도형 차량 시뮬레이션을 구축하여 실제 포장정보를 이용해 생성 된 경로의 적용 가능성을 구명하고자 하였다. 자율주행 콤바인 경로 계획은 콤바인의 길이, 너비, 회전 시 좌 우 궤도의 속도 비, 직진 속도와 회전 속도 비, 회전 각도, 포장의 외부 경계선, 작업 겹침 량, 회경 횟수를 이용하여 좌현 새머리 선회를 포함한 내부 왕복작업 경로를 생성하며 외부 회경 횟수는 2~3회를 가정하였다. 자율주행 시뮬레이션은 차체와 궤도 자체의 미끄러짐과 작동기 지연시간을 단순화 한 궤도형 기구학 모델형태로 구성하였다. 추종 알고리즘은 선견 거리법을 사용하였으며, 측면 변이값과 방향 오차의 선형조합을 이용하여 조향변수를 정의하고 퍼지로직기반으로 좌 우 궤도 속도를 7 단계화하여 조향장치를 모델링하였다. 실험결과 개발 된 경로생성 알고리즘은 실제 취득 된 포장 외부 경계 GPS 위 경도를 이용해 자동으로 생성이 가능하며 간략화 된 콤바인 시뮬레이션에서 직진주행 RMS 위치 오차는 0.05 m, 선회구간에서 직진 구간 진입 시 RMS 위치 오차는 0.11 m, 직진 구간 RMSE 방향 오차는 3.2 deg로 콤바인 예취부 간격인 30 cm보다 작은 위치 오차를 보이며 생성된 경로 전체 추종이 가능함을 나타내었다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.3
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• pp.248-257
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• 2011

In the present study, we proposed a new numerical wave tank model to analyze the vertical tension-leg circular floating bodies, using a 2-D Navier-Stokes solver. An IBM(Immersed Boundary Method) capable of handling interactions between waves and moving structures with complex geometry on a standard regular Cartesian grid system is coupled to the VOF(Volume of Fluid) method for tracking the free surface. Present numerical results for the motions of the floating body were compared with existing experimental data as well as numerical results based on FAVOR(Fractional Area Volume Obstacle Representation) algorithm. For detailed examinations of the present model, the additional hydraulic experiments for floating motions and free surface transformations were conducted. Further, the versatility of the proposed numerical model was verified via the numerical and physical experiments for the general rectangular floating bodies. Numerical results were compared with experiments and good agreement was archived.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.227-237
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• 2002

A numerical technique for simulating the aggregation of charged particles was presented with a Brownian dynamic simulation in the free molecular regime. The Langevin equation was used for tracking each particle making up an aggregate. A periodic boundary condition was used for calculation of the aggregation process in each cell with 500 primary particles of 16 nm in diameter. We considered the thermal force and the electrostatic force for the calculation of the particle motion. The electrostatic force on a particle in the simulation cell was considered as a sum of electrostatic forces from other particles in the original cell and its replicate cells. We assumed that the electric charges accumulated on an aggregate were located on its center of mass, and aggregates were only charged with pre-charged primary particles. The morphological shape of aggregates was described in terms of the fractal dimension. In the simulation, the fractal dimension for the uncharged aggregate was D$\_$f/ = 1.761. The fractal dimension changed slightly for the various amounts of bipolar charge. However, in case of unipolar charge, the fractal dimension decreased from 1.641 to 1.537 with the increase of the average number of charges on the particles from 0.2 to 0.3 in initial states. In the bipolar charge state, the average sizes of aggregates were larger than that of the uncharged state in the early and middle stages of aggregation process, but were almost the same as the case of the uncharged state in the final stage. On the other hand, in the unipolar charge state, the average size of aggregates and the dispersion of particle volume decreased with the increasing of the charge quantities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1C
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• pp.26-35
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• 2006

In this paper, an automatic mobile robot system for a intelligent path planning using the detection scheme of the spatial coordinates based on stereo camera is proposed. In the proposed system, face area of a moving person is detected from a left image among the stereo image pairs by using the YCbCr color model and its center coordinates are computed by using the centroid method and then using these data, the stereo camera embedded on the mobile robot can be controlled for tracking the moving target in real-time. Moreover, using the disparity map obtained from the left and right images captured by the tracking-controlled stereo camera system and the perspective transformation between a 3-D scene and an image plane, depth information can be detected. Finally, based-on the analysis of these calculated coordinates, a mobile robot system is derived as a intelligent path planning and a estimation. From some experiments on robot driving with 240 frames of the stereo images, it is analyzed that error ratio between the calculated and measured values of the distance between the mobile robot and the objects, and relative distance between the other objects is found to be very low value of $2.19\%$ and $1.52\%$ on average, respectably.

• Korean Journal of Remote Sensing
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• v.34 no.6_4
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• pp.1479-1488
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• 2018

On September 3rd 2017, strong artificial seismic signals from North Korea were detected in KMA (Korea Meteorological Administration) seismic network. The location of the epicenter was estimated to be Punggye-ri nuclear test site and it was the most powerful to date. The event was not studied well due to accessibility and geodetic measurements. Therefore, we used remote sensing data to analyze surface changes around Mt. Mantap area. First of all, we tried to detect surface deformation using InSAR method with Advanced Land Observation Satellite-2 (ALOS-2). Even though ALOS-2 data used L-band long wavelength, it was not working well for this particular case because of decorrelation on interferogram. The main reason would be large deformation near the Mt. Mantap area. To overcome this limitation of decorrelation, we applied offset tracking method to measure deformation. However, this method is affected by window kernel size. So we applied various window sizes from 32 to 224 in 16 steps. We could retrieve 2D surface deformation of about 3 m in maximum in the west side of Mt. Mantap. Second, we used Pleiadas-A/B high resolution satellite optical images which were acquired before and after the 6th nuclear test. We detected widespread surface damage around the top of Mt. Mantap such as landslide and suspected collapse area. This phenomenon may be caused by a very strong underground nuclear explosion test. High-resolution satellite images could be used to analyze non-accessible area.

• Progress in Medical Physics
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• v.23 no.2
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• pp.91-98
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• 2012

Verification of internal organ motion during treatment and its feedback is essential to accurate dose delivery to the moving target. We developed an offline based internal organ motion verification system (IMVS) using cine EPID images and evaluated its accuracy and availability through phantom study. For verification of organ motion using live cine EPID images, a pattern matching algorithm using an internal surrogate, which is very distinguishable and represents organ motion in the treatment field, like diaphragm, was employed in the self-developed analysis software. For the system performance test, we developed a linear motion phantom, which consists of a human body shaped phantom with a fake tumor in the lung, linear motion cart, and control software. The phantom was operated with a motion of 2 cm at 4 sec per cycle and cine EPID images were obtained at a rate of 3.3 and 6.6 frames per sec (2 MU/frame) with $1,024{\times}768$ pixel counts in a linear accelerator (10 MVX). Organ motion of the target was tracked using self-developed analysis software. Results were compared with planned data of the motion phantom and data from the video image based tracking system (RPM, Varian, USA) using an external surrogate in order to evaluate its accuracy. For quantitative analysis, we analyzed correlation between two data sets in terms of average cycle (peak to peak), amplitude, and pattern (RMS, root mean square) of motion. Averages for the cycle of motion from IMVS and RPM system were $3.98{\pm}0.11$ (IMVS 3.3 fps), $4.005{\pm}0.001$ (IMVS 6.6 fps), and $3.95{\pm}0.02$ (RPM), respectively, and showed good agreement on real value (4 sec/cycle). Average of the amplitude of motion tracked by our system showed $1.85{\pm}0.02$ cm (3.3 fps) and $1.94{\pm}0.02$ cm (6.6 fps) as showed a slightly different value, 0.15 (7.5% error) and 0.06 (3% error) cm, respectively, compared with the actual value (2 cm), due to time resolution for image acquisition. In analysis of pattern of motion, the value of the RMS from the cine EPID image in 3.3 fps (0.1044) grew slightly compared with data from 6.6 fps (0.0480). The organ motion verification system using sequential cine EPID images with an internal surrogate showed good representation of its motion within 3% error in a preliminary phantom study. The system can be implemented for clinical purposes, which include organ motion verification during treatment, compared with 4D treatment planning data, and its feedback for accurate dose delivery to the moving target.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.355-362
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• 2008

Fast track completion of urgent typhoon damage recovery construction project is becoming crucial for the prevention of the secondary damage from the next year typhoon, prompt psychological stabilization of flood sufferers, the early recovery of damaged infrastructure condition and so forth. As the recovery learning process has been continued for last consecutive typhoons and experts suggested, the keys in attaining the goals of the project (preventative, sustainable, cleaner and fast tracking development) are found to be the early contracting and improved competencies in project management especially during the design phase. It can be presumed that the former is attainable through administrative supports in the form of government guidelines, but the latter necessitates more research efforts. In this regards, this study aims to find a way how to lift up the current level of project management capability facing ever changing project mangement environment of urgent typhoon recovery project. By comparing the current level of application of government guidelines in flooded districts and analyzing the time required for each phase from design contracting to construction starting, several reformative ideas are illustrated in association with the necessity of adopting CM method in the deign phase. It is highly expected that CM application in the design phase can be an effective alternative in overcoming current limits in improving the quality of the project and prevent the delay due to the lack of expertise and professional workers in the owner side.

• Progress in Medical Physics
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• v.29 no.1
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• pp.8-15
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• 2018

This work reports the acceptance testing and commissioning experience of the Robotic Intensity-Modulated Radiation Therapy (IMRT) M6 system with a newly released $InCise^{TM}2$ Multileaf Collimator (MLC) installed at the Yonsei Cancer Center. Acceptance testing included a mechanical interdigitation test, leaf positional accuracy, leakage check, and End-to-End (E2E) tests. Beam data measurements included tissue-phantom ratios (TPRs), off-center ratios (OCRs), output factors collected at 11 field sizes (the smallest field size was $7.6mm{\times}7.7mm$ and largest field size was $115.0mm{\times}100.1mm$ at 800 mm source-to-axis distance), and open beam profiles. The beam model was verified by checking patient-specific quality assurance (QA) in four fiducial-inserted phantoms, using 10 intracranial and extracranial patient plans. All measurements for acceptance testing satisfied manufacturing specifications. Mean leaf position offsets using the Garden Fence test were found to be $0.01{\pm}0.06mm$ and $0.07{\pm}0.05mm$ for X1 and X2 leaf banks, respectively. Maximum and average leaf leakages were 0.20% and 0.18%, respectively. E2E tests for five tracking modes showed 0.26 mm (6D Skull), 0.3 mm (Fiducial), 0.26 mm (Xsight Spine), 0.62 mm (Xsight Lung), and 0.6 mm (Synchrony). TPRs, OCRs, output factors, and open beams measured under various conditions agreed with composite data provided from the manufacturer to within 2%. Patient-specific QA results were evaluated in two ways. Point dose measurements with an ion chamber were all within the 5% absolute-dose agreement, and relative-dose measurements using an array ion chamber detector all satisfied the 3%/3 mm gamma criterion for more than 90% of the measurement points. The Robotic IMRT M6 system equipped with the $InCise^{TM}2$ MLC was proven to be accurate and reliable.

• Korean Journal of Biological Psychiatry
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• v.3 no.2
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• pp.277-287
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• 1996

Objective : It has been proposed that cognition and related aspects of mental functioning are decreased in depression as well as in alcoholism. The objective of the study was to compare behavioral side effects of paroxetine and amitriptyline in depressed patients accompanied by alcoholism. The focused comparisons were drug effects concerning psychomotor performance, cognitive function, sleep and daytime sleepiness during the first 2 weeks of treatment. Methods : After an alcohol detoxification period(3 weeks) and a washout period(1 week), a total of 20 male inpatients with alcohol use disorder (DSM-IV), who also had a major depressive episode(DSM-IV), were treated double-blind with paroxetine 20mg/day(n=10) or amitriptyline 25mg/day(n=10) for 2 weeks. All patients were required to have a scare of at least 18 respectively on bath the Hamilton Rating Scale far Depression(HAM-D) and Beck Depression Inventory(BDI) at pre-drug baseline. Patients randomized to paroxetine received active medication in the morning and placebo in the evening whereas those randomized to amitriptyline received active medication in the evening and placebo in the morning. All patients performed the various tasks in a test battery at baseline and at days 3, 7 and 14. The test battery included : critical flicker fusion threshold for sensory information processing capacity : choice reaction time for gross psychomotor performance : tracking accuracy and latency of response to peripheral stimulus as a measure of line sensorimotor co-ordination and divided attention : digit symbol substitution as a measure of sustained attention and concentration. To rate perceived sleep and daytime sleepiness, 10cm line Visual analogue scales were employed at baseline and at days 3, 7 and 14. The subjective rating scales were adapted far this study from Leeds sleep Evaluation Questionnaire and Epworth Sleepiness Scale. In addition a comprehensive side effect assessment, using the UKU side effect rating scale, was carried out at baseline and at days 7 and 14. The efficacy of treatment was evaluated using HAM-D, BDI and clinical global impression far severity and improvement at days 7 and 14. Results : The pattern of results indicated thai paroxetine improved performance an mast of the lest variables and also improved sleep with no effect on daytime sleepiness aver the study period. In contrast, amitriptyline produced disruption of performance on same tests and improved sleep with increased daytime sleepiness in particular at day 3. On the UKU side effect rating scale, mare side effects were registered an amitriptyline. The therapeutic efficacy was observed in favor of paroxetine early in day 7. Conclusion : These results demonstrated thai paroxetine in much better than amitriptyline for the treatment of depressed patients accompained by alcoholism at least in terms of behavioral safety and tolerability, furthermore the results may assist in explaining the therapeutic outcome of paroxetine. For example, and earlier onset of antidepressant action of paroxetine may be caused by early improved cognitive function or by contributing to good compliance with treatment.