• Title/Summary/Keyword: Magnetic Object

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A Study on the Design Expert System for Research and Development Using Blackboard Inference Model (신제품개발용 전문가시스템에 있어서의 지식처리 기법으로서 흑판형 추론 모델의 적용 방법에 관한 연구)

  • Jang, Seung Ho
    • Journal of the Korea Society for Simulation
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    • v.22 no.1
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    • pp.87-95
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    • 2013
  • In the research and development processes of new product, the design objects are frequently redesigned on the basis of experimental results. Most of the conventional CAD systems are based on the computer simulation to reduce the number of redesign. However, these types of CAD systems do not have the functions to infer the cause of trouble in experiments of mock-up and the redesign counterplan of new product. This paper proposes a methodology to establish the DESYR ver. 1(Design Expert SYstem for Research and development) system, which possesses the engineering model of design object in the model database, and refines the model on the basis of experimental results of the prototype. The blackboard inference model has been applied to infer the redesign counterplan. And the validity of DESYR ver. 1 system has been verified by developing the new type of magnetic bearing.

Anticorrosive Monitoring and Complex Diagnostics of Corrosion-Technical Condition of Main Oil Pipelines in Russia

  • Kosterina, M.;Artemeva, S.;Komarov, M.;Vjunitsky, I.;Pritula, V.
    • Corrosion Science and Technology
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    • v.7 no.4
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    • pp.208-211
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    • 2008
  • Safety operation of main pipelines is primarily provided by anticorrosive monitoring. Anticorrosive monitoring of oil pipeline transportation objects is based on results of complex corrosion inspections, analysis of basic data including design data, definition of a corrosion residual rate and diagnostic of general equipment's technical condition. All the abovementioned arrangements are regulated by normative documents. For diagnostics of corrosion-technical condition of oil pipeline transportation objects one presently uses different methods such as in-line inspection using devices with ultrasonic, magnetic or another detector, acoustic-emission diagnostics, electrometric survey, general external corrosion diagnostics and cameral processing of obtained data. Results of a complex of diagnostics give a possibility: $\cdot$ to arrange a pipeline's sectors according to a degree of corrosion danger; $\cdot$ to check up true condition of pipeline's metal; $\cdot$ to estimate technical condition and working ability of a system of anticorrosive protection. However such a control of corrosion technical condition of a main pipeline creates the appearance of estimation of a true degree of protection of an object if values of protective potential with resistive component are taken into consideration only. So in addition to corrosive technical diagnostics one must define a true residual corrosion rate taking into account protective action of electrochemical protection and true protection of a pipeline one must at times. Realized anticorrosive monitoring enables to take a reasonable decision about further operation of objects according to objects' residual life, variation of operation parameters, repair and dismantlement of objects.

The Correlation of MRI Findings to Outcome in Diffuse Axonal Injury Patients (미만성 뇌축삭손상 환자의 자기공명영상 소견과 예후와의 상관관계)

  • Oh, Kyung Seup;Ha, Sung Il;Suh, Bumn Suk;Lee, Hyun Sung;Lee, Jong Soo
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup1
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    • pp.20-24
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    • 2001
  • Object : We intended to investigate the relationship between the degree of injury on MRI and the outcome of the patients with diffuse axonal inury. Method : From january, 1995 to march, 1999, 22 patients were supposed to have diffuse axonal injuries by means of their neurologic signs and MRI. We investigated their prognosis according to CT, MRI and initial neurologic findings. Result : 1) The lesions were mainly located at white matter of cerebrum, corpus callosum, brainstem, and basal ganglia. 2) The lesions of white matter were most commonly in the frontal lobe and temporal lobe. 3) The majority of corpus callosal lesions were located in the posterior body and splenium, but anterior corpus callosal lesions combined with posterior lesions were not found. 4) Brainstem lesions, all non-hemorrhagic, were mostly located in the dorsolateral aspect, not be found on CT. 5) The brainstem lesions were found in 10 cases among total 22 cases, and corpus callosal lesions were accompanied with 8 cases of brainstem lesions. 6) The patients with brainstem lesions had worse prognosis. Conclusion : It is important and reasonable to take brain MRI to identify the brainstem lesions in any cases of suspicious diffuse axonal injury, and we should remind that the diffuse axonal injury with stem lesion has worse prognosis.

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3D Reconstruction of Tissue from a few of MRI Images using Radial Basis Function (BBF를 이용한 적은 수의 MRI 이미지로부터 3차원 조직 재구성)

  • Shin, Young-Seok;Kim, Hyoung-Seok B.
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.2077-2082
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    • 2008
  • Recent the advanced technologies in medical imaging such as magnetic resonance imaging (MRI) and computed tomography (CT) make doctors improve the diagnostic skill with detailed anatomical information. In general, it is necessary to get a number of MRI images in order to obtain more detail information. However, the performance of MRI machines of privately run hospitals is not good and thus we may obtain only a few of MRI images. If 3D surface reconstruction is accomplished with a few slices, then it generates 3D surface of poor qualify. This paper propose a way to Set a 3D surface of high quality from a few of number of slices. First of all, our algorithm detects the boundary of tissues which we want to reconstruct as a 3D object and find out the set of vortices on the boundary. And then we generate a 3D implicit surface to interpolate the boundary points by using radial basis function. Lastly, we render the 3D implicit surface by using Marching cube algorithms.

Development of Augmented Reality Character System based on Markerless Tracking (마커리스 트래킹 기반 증강현실 캐릭터 시스템 개발)

  • Hyun, Sim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.6
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    • pp.1275-1282
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    • 2022
  • In this study, real-time character navigation using AR lens developed by Nreal is developed. Real-time character navigation is not possible with general marker-based AR because NPC characters must guide while moving in an unspecified space. To replace this, a markerless AR system was developed using Digital Twin technology. Existing markerless AR is operated based on hardware such as GPS, gyroscope, and magnetic sensor, so location accuracy is low and processing time in the system is long, resulting in low reliability in real-time AR environment. In order to solve this problem, using the SLAM technique to construct a space into a 3D object and to construct a markerless AR based on point location, AR can be implemented without any hardware intervention in a real-time AR environment. This real-time AR environment configuration made it possible to implement a navigation system using characters in tourist attractions such as Suncheon Bay Garden and Suncheon Drama Filming Site.

Suppression of stray electrons in the negative ion accelerator of CRAFT NNBI test facility

  • Yuwen Yang ;Jianglong Wei ;Junwei Xie ;Yuming Gu;Yahong Xie ;Chundong Hu
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.939-946
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    • 2023
  • Comprehensive Research Facility for Fusion Technology (CRAFT) is an integration of different demonstrating or testing facilities, which aim to develop the critical technology or composition system towards the fusion reactor. Due to the importance and challenge of the negative ion based neutral beam injection (NNBI), a NNBI test facility is included in the framework of CRAFT. The initial object of CRAFT NNBI test facility is to obtain a H0 beam power of 2 MW at the energy of 200-400 keV for the pulse duration of 100 s. Inside the negative ion accelerator of NNBI system, the interactions of the negative ions with the background gas and electrodes can generate abundant stray electrons. The stray electrons can be further accelerated and dumped on the electrodes or eject from the accelerator. The stray electrons, including the ejecting electrons, cause the unwanted particle and heat flux onto the electrodes and the inner components of beamline (especially the temperature sensitive cryopump). The suppression of the stray electrons from the CRAFT accelerator is carried out via a series of design and simulation works. The paper focuses the influence of different magnetic field configurations on the stray electrons and the character of the ejecting electrons.

AR-Based Character Tracking Navigation System Development (AR기반 캐릭터 트래킹 네비게이션 시스템 개발)

  • Lee, SeokHwan;Lee, JungKeum;Sim, Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.2
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    • pp.325-332
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    • 2022
  • In this study, real-time character navigation using AR lens developed by Nreal is developed. Real-time character navigation is not possible with general marker-based AR because NPC characters must guide while moving in an unspecified space. To replace this, a markerless AR system was developed using Digital Twin technology. Existing markerless AR is operated based on hardware such as GPS, gyroscope, and magnetic sensor, so location accuracy is low and processing time in the system is long, which results low reliability in real-time AR environment. In order to solve this problem, using the SLAM technique to construct a space into a 3D object and to construct a markerless AR based on point location, AR can be implemented without any hardware intervention in a real-time AR environment. This real-time AR environment configuration made it possible to implement a navigation system using characters in tourist attractions such as Suncheon Bay Garden and Suncheon Drama Filming Site.

Applications of Artificial Intelligence in MR Image Acquisition and Reconstruction (MRI 신호획득과 영상재구성에서의 인공지능 적용)

  • Junghwa Kang;Yoonho Nam
    • Journal of the Korean Society of Radiology
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    • v.83 no.6
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    • pp.1229-1239
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    • 2022
  • Recently, artificial intelligence (AI) technology has shown potential clinical utility in a wide range of MRI fields. In particular, AI models for improving the efficiency of the image acquisition process and the quality of reconstructed images are being actively developed by the MR research community. AI is expected to further reduce acquisition times in various MRI protocols used in clinical practice when compared to current parallel imaging techniques. Additionally, AI can help with tasks such as planning, parameter optimization, artifact reduction, and quality assessment. Furthermore, AI is being actively applied to automate MR image analysis such as image registration, segmentation, and object detection. For this reason, it is important to consider the effects of protocols or devices in MR image analysis. In this review article, we briefly introduced issues related to AI application of MR image acquisition and reconstruction.

Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

Time Resolution Improvement of MRI Temperature Monitoring Using Keyhole Method (Keyhole 방법을 이용한 MR 온도감시영상의 시간해상도 향상기법)

  • Han, Yong-Hee;Kim, Tae-Hyung;Chun, Song-I;Kim, Dong-Hyeuk;Lee, Kwang-Sig;Eun, Choong-Ki;Jun, Jae-Ryang;Mun, Chi-Woong
    • Investigative Magnetic Resonance Imaging
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    • v.13 no.1
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    • pp.31-39
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    • 2009
  • Purpose : This study proposes the keyhole method in order to improve the time resolution of the proton resonance frequency(PRF) MR temperature monitoring technique. The values of Root Mean Square (RMS) error of measured temperature value and Signal-to-Noise Ratio(SNR) obtained from the keyhole and full phase encoded temperature images were compared. Materials and Methods : The PRF method combined with GRE sequence was used to get MR temperature images using a clinical 1.5T MR scanner. It was conducted on the tissue-mimic 2% agarose gel phantom and swine's hock tissue. A MR compatible coaxial slot antenna driven by microwave power generator at 2.45GHz was used to heat the object in the magnetic bore for 5 minutes followed by a sequential acquisition of MR raw data during 10 minutes of cooling period. The acquired raw data were transferred to PC after then the keyhole images were reconstructed by taking the central part of K-space data with 128, 64, 32 and 16 phase encoding lines while the remaining peripheral parts were taken from the 1st reference raw data. The RMS errors were compared with the 256 full encoded self-reference temperature image while the SNR values were compared with the zero filling images. Results : As phase encoding number at the center part on the keyhole temperature images decreased to 128, 64, 32 and 16, the RMS errors of the measured temperature increased to 0.538, 0.712, 0.768 and 0.845$^{\circ}C$, meanwhile SNR values were maintained as the phase encoding number of keyhole part is reduced. Conclusion : This study shows that the keyhole technique is successfully applied to temperature monitoring procedure to increases the temporal resolution by standardizing the matrix size, thus maintained the SNR values. In future, it is expected to implement the MR real time thermal imaging using keyhole method which is able to reduce the scan time with minimal thermal variations.

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