• Nuclear Engineering and Technology
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• v.33 no.3
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• pp.315-326
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• 2001

Direct ECC bypass phenomena that occur in a reactor vessel downcomer with a Direct Vessel Injection (DVI) system during the reflood phase of a Large Break Loss-of-Coolant Accident (LBLOCA) are experimentally investigated using a transparent l/7.5 scaled down test facility of the Upper Plenum Test Facility (UPTF). A series of separate effect tests are peformed in order to investigate the mechanisms of direct ECC bypass and to find out its scaling parameters. Various flow regimes and phasic distribution in downcomer are identified and mapped, and the fraction of direct ECC bypass is measured under a wide range of air and water injection conditions. From the counterpart test of the UPTF Test 21-D, the dimensionless gas velocity ( $j^{*}$$_{g,eff}$) is derived experimentally, which is believed to be a major scaling parameter for the fraction of direct ECC bypass. And it is found out that the direct ECC bypass is greatly affected by the spreading width of ECC water film and the geometric configuration of the downcomer.r.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1227-1234
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• 2017

The two-degree-of-freedom direct drive induction motor, which is capable of linear, rotary and helical motion, has a wide application in special industry such as industrial robot arms. It is inevitable that the linear motion and rotary motion generate coupling effect on each other on account of the high integration. The analysis of this effect has great significance in the research of two-degree-of-freedom motors, which is also crucial to realize precision control of them. The coupling factor considering the coupling effect is proposed and addressed by 3D finite element method. Then the corrected mathematical model is presented by importing the coupling factor. The results from it are verified by 3D finite element model and prototype test, which validates the corrected mathematical model.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6007-6010
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• 2015

Background: Chronic lymphoid leukemia (CLL) is a malignant hematopoietic disorder, the most common of all adult leukemias with a distinctive immunophenotype. It is well established that CLL patients can have autoimmune complications, amongst them autoimmune hemolytic anemia as the most frequent. This study was carried out to determine the frequency of direct Coombs Test positivity in CLL patients and its possible correlation with Rai staging, hematological parameters and biochemical markers. Materials and Methods: This descriptive cross sectional study was carried at Liaquat National Hospital from January 2011 to June 2013. Sixty untreated patients with B- chronic lymphoid leukemia were enrolled. Complete blood count, direct Coombs test, serum urea, creatinine, uric acid and LDH levels were determined. Data were compiled and analyzed using SPSS version 21. Results: Out of 60 patients, 42(70%) were males and 18(30%) were females. Mean age was $59{\pm}9.2years$. Male to female ratio was 2.1: 1. The frequency of direct antiglobulin test (DAT) positivity was found to be 23.3%. The monospecific IgG was positive in 11 patients (18.3%); C3d positivity was evident in 1 patient (1.6%) and 2 patients (3.3%) had dual IgG and C3d positivity. The mean hemoglobin was $10.8{\pm}2.4gm/dl$. Significantly low mean hemoglobin of $8.3{\pm}3.0gm/dl$ was seen in Coombs positive patients compared with negative patients having a mean hemoglobin level of $11.7{\pm}1.6gm/dl$ (P<0.001). DAT positivity also demonstrated a positive association with advanced Rai stage III disease (P<0.01). No associations were noted with age, gender and biochemical markers. Conclusions: Direct Coombs test positivity in CLL in our patients, unlike in Western studies, appears relatively high, indicating significant autoimmune hemolytic anemia and advanced Rai stage in our setting. DAT positivity can be considered as a surrogative marker for advanced clinical disease.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.205-211
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• 1994

The best method is selected among the 3 digital dynamic compensation methods which are developed or applied for the Rhodium self-powered neutron detector. The three digital dynamic compensation methods are the existing Dominant Pol Tustin method of the COLSS(Core Operating Limit Supervisory System), the Direct Inversion method and Kalman Filter method. The Direct Inversion method is an improved method of D. Hoppe and R. Maletti and the Kalman Filter method is developed using the Kalman Filter. Response times of the compensated signals to achieve 90% of a step input are 28.1, 17.2 and 6.5 seconds respectively for the same noise gain telling that the Kalman Filter method is the best amens the 3 methods.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.10 s.175
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• pp.31-38
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• 2005

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.27-31
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• 2014

In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.407-411
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• 2005

In this research, we develop 3D online racing game to aid the comprehension about resource recycling, in the way of provoking children's interest and satisfying scientific curiosity, using 3D graphic editor and DirectX programming tool. This game is developed for children to experience the collection and classification procedure of recycling resources by only taking part in a game naturally, and to learn recycling-process contents produced using animation technique. Especially, we make this game to utilize it as an educational and public medium at home and abroad, and to interchange with foreign institutes, by offering korean version as well as english version. As a result, this game can be used as educational contents about resource recycling, because it is developed in the style that children can enjoy it directly.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.391-394
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• 2003

Laser direct writing process is developed 3rd harmonic Diode Pumped Solid State Laser with the near visible wavelength of 355 m sensitive polymer is irradiated by UV laser and developed using polymer solvent to obtain quasi-3D. It is important to reduce line width for image mode waveguides, so some investigations will be carried out in various conditions of process parameters such as laser power, writing speed, laser focus and optical properties of polymer. This process could be to fabricate a single mode waveguide without expensive mask projection method. Experimentally, the patterns of trapezoidal shape were manufactured into dimension of 8.4 mm width and 7.5 mm height. Propagation loss of straight waveguide measured 3 dB/cm at 1,550 nm.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.169-176
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• 2017

Casting process includes wax pattern, investment, dewaxing, curing, casting, etc., and each single process is important to achieve a good result. Since 2000, 3D printers have been developed and widely used; as more prefer UV Curavle resin method over wax method, resultant casting defects have become worse. To resolve such problem, preceding research revealed casting defects of existing wax method. In particular, defects of UV Curavle resin method showed difference in investment, dewaxing, deresinating and curing compared to the existing one. Accordingly, results were presented through casting tests; especially, a temperature rising curve only for UV Curavle resin was shown rather than one for the existing method. Lastly, this research classified those not available with direct casting and suggested mold manufacturing. This research is expected to be useful for 3D printer users or those who would conduct direct casting with UV Curavle resin.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.231-234
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• 2001

위성방송 수신을 위한 S-band용 LNB를 유전율3.48, 기판두께 0.762mm의 기판을 사용하여 NF=0.9 dB, 변환이득 56dB, Gain Flatness +0.7dB/27MHz을 만족하도록 설계하였으며 대역통과필터는 원하는 대역내에서 삽입손실 -2dB, 반사계수 -l2dB 이하의 결과를 얻었다. 발진기는 3.62GHz에서 6.17dBm의 출력을 나타내었으며 위상잡음은 중심주파수 3.62GHz의 100kHz offset 지점에서 -98 dBc/Hz의 특성을 얻었다.