• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.74-84
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• 1996

Dynamic loading of structures often causes excursions of stresses well into the inelastic range and the influence of geometric changes on the dynamic response is also significant in many cases. Therefore, both material and geometric nonlinearity effects should be considered in case that a dynamic load acts on the structure. For developing a program to analyze the dynamic response of an axisymmetric shell in this study, the material nonlinearity effect on the dynamic response was formulated by the elasto-viscoplastic model highly corresponding to the real behavior of the material. Also, the geometrically nonlinear behavior is taken into account using a total Lagrangian coordinate system, and the equilibrium equation of motion was numerically solved by a central difference scheme. A complete finite element program has been developed and the results obtained by it are compared with those in the references 1 and 2. The results are in good agreement with each other. As a case study of its application, the developed program was applied to a dynamic response analysis of a nuclear reinforced concrete containment structure. The results obtained from the' numerical examples are summarized as follows : 1. The dynamic magnification factor of the displacement and the stress were unrelated with the concrete strength. 2. As shown by the results that the displacement dynamic magnification factor were form 1.7 to 2.3 and the stress dynamic magnification factor from 1.8 to 2.5, the dynamic magnification factor of stress were larger than that of displacement. 3. The dynamic magnification factor of stress on the exterior surface was larger than that on the interior surface of the structure.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1136-1142
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• 1999

A difficulty of the visual inspection for translated, magnified and rotated objects exists owing to the limitation of recognition rate. In this paper, we perform to define Integral Logarithm Transform(ILT), to consider its characteristic for implementation of Translation-, Magnification- and Rotation-invariant inspection system, and to compare with other methods in inspection error rate. By using magnification and rotation invariance properties of ILT, it makes easier than other methods to extract the rotation degree. The new method employs the ILT for the good/bad inspection of translated, magnified and rotated objects and experiment is performed to achieve translation, magnification and rotation invariance. In other methods both magnification and rotation invariance can't be available. As the result of he experiment, it is not better than the self-organizing map in the improvement of recognition rate, but it shows us the possibility to be used as a tool for the good/bad inspection system.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.452-456
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• 2010

Purpose: The schwannoma is a benign peripheral nerve tumor arising from the Schwann cell of the nerve sheath. Only 2-8% of schwannomas arise in the hand and wrist. Misdiagnosis is frequent such as ganglion and neurofibroma. This article documents and clarifies the clinical features of schwannomas arising in the hand and wrist, and emphasizes importance of differential diagnosis and meticulous surgical extirpation under magnification. Methods: The author reviewed clinical features of 15 patients with pathologic final diagnosis of schwannoma developed in hand and wrist during the last 12 years from 1998 through 2009. The review included the sex, age of onset, duration, preoperative diagnosis, location, involved nerve, preoperative symptoms and. Postoperative sequelae after surgical extirpation of the lesion with magnification, or without magnification of the surgical fields. Results: The chief complaints were slow growing firm mass in all patients, and followed by pain in 40%, and paresthesia in 40% respectively. The lesions were developed solitarily in 14 patients (93%). The postoperative pathologic diagnosis and preoperative diagnosis were coincided with only in 6 patients (40%). Other preoperative diagnosis were soft tissue tumor in 4 patient (26.6%), and ganglion in 3 patients (20%), and neurofibroma in 2 patients (13%). In all patients who were undergone surgical excision under the fields of magnification, all symptoms were subsided without any sequelae. Meanwhile muscle weakness, paresthesia, hypoesthesia and /or accidental nerve resection developed after surgical excision with naked eye. Conclusion: Schwannoma in hand most commonly appears as a slow growing solitary mass with pain or paresthesia. The chance of preoperative misdiagnosis was 60% in this series. To provide good prognosis and less sequelae, careful and elaborate diagnostic efforts and meticulous surgical excision under the magnification are necessary in management of schwannoma.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.313-320
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• 2022

Both angiography and interventional procedures accompanied by angiography provide many diagnostic and therapeutic benefits to patients and are rapidly increasing. However, unlike general radiography or computed tomography using the same X-ray, the amount of radiation is quite high, but the dose range can vary considerably for each patient and operator. The high sensitivity of the lens to radiation during cerebral angiography and neurointervention is already well known, and although there are many related studies, it is insufficient to easily reduce radiation in diagnosis and treatment. In this situation, in particular, by adding three-dimensional rotational angiography (3D-RA) to the existing two-dimensional (2D) angiography, it is now possible to make an accurate diagnosis. However, since this 3D-RA acquires images through projection of more radiation than before, the exposure dose of the lens may be higher. Therefore, we tried to analyze whether the radiation dose of the lens can be reduced by moving the lens out of the field range by adjusting the table height and magnification ratio during the examination using 3D-RA. The surface dose was measured using a rando phantom and a radiophotoluminescent glass dosimeter (PLD) and the radiation dose was compared by adjusting the table height and magnification ratio based on the central point. As a result, it was found that the radiation dose of the lens decreased as the table height increased from the central point, that is, as the lens was out of the field of view. In conclusion, in 3D-RA, moving the table position of about 2 cm in height will make a significant contribution to the dose reduction of the lens, and it was confirmed that adjusting the magnification ratio can also reduce the surface dose of the lens.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.11 s.116
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• pp.1165-1171
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• 2006

This paper presents a new type of jetting dispenser for the integrated circuit (IC) fabrication and surface mount technology The proposed system is featured by the piezoelectric actuator and hydraulic magnification device. After describing structural component of the dispensing mechanism and its operation principle, both the fluid modeling and the hydraulic magnification modeling are undertaken with a lumped-parameter method based on the analogy of the fluid system and mechanical system. A mathematical governing equation is then derived by integrating the fluid model with the mechanical model of the driving piston and piezoelectric actuator. Subsequently, in order to achieve a desired dispensing amount, control algorithm adjusting duty cycle of the driving voltage is synthesized and control responses are presented in time domain.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.428-433
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• 2006

This paper presents a new type of jetting dispenser for the integrated circuit(IC) fabrication and surface mount technology. The proposed system is featured by the piezoelectric actuator and hydraulic magnification device. After describing structural component of the dispensing mechanism and its operation principle, both the fluid modeling and the hydraulic magnification modeling are undertaken with a lumped-parameter method based on the analogy of the fluid system and mechanical system. A mathematical governing equation is then derived by integrating the fluid model with the mechanical model of the driving piston and piezoelectric actuator. Subsequently, in order to achieve a desired dispensing amount, control algorithm adjusting duty cycle of the driving voltage is synthesized and control responses are presented in time domain.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.173-176
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• 2005

This study look into the mechanisms of growth and magnification in the cracks and delamination on the beams repaired with CFS. The experimental parameters was a loading type, loading speed and pre-crack. In the experiments, it was confirmed that the failure of beams began with development and propagation of the delamination in the below the loading point due to magnification of cracks, but it was not concerned with loading type, loading speed and pre-cracks. Particularly, in the case of beams having the pre-cracks, growth of crack concentrated at the special crack below the loading point and led to failure of the beam by delamination due to magnification of crack.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1402-1404
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• 2000

The electrified railway has various power supply schemes. Although the identical trains are operated in same condition and the impedance of track are equal, the genealogy impedance of track is changed according to composition method of feeding scheme. So, the harmonic current flowing into the railway substation are greatly unlike. For simulation of harmonic magnification flowing into the railway substation according to feeding scheme, we propose 6-port network analysis method based on 4-port network, find 6-port equivalent model of each circuit component, and compare and investigate harmonic magnification in the case of parallel post and normal feeding scheme.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.9 no.1
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• pp.19-23
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• 1979

A study was made primarily to investigate vertical and horizontal distortion of the image at the apical region of the dental roots in orthopantomographs. The subjects consisted of two dry skulls with radiopaque materials attached to root surface. Measuring of the width and length of each predetermined point at 23 teeth was performed in dry skulls and radiographic films. The results obtained were as follows; 1. There was overall magnification of image in the vertical dimension. And anterior portion had greater magnification rate than posterior portion, while lower anterior portion had less magnification rate than upper anterior portion. 2. There was reduction of the image in the horizontal dimension of the teeth, because of the position relation between dry skull and image layer of the orthopantomograph. 3. There was a significant difference in distortion rate between the oposite teeth. 4. Cervical portion of the tooth had more decreased rate of horizontal distortion than apical portion.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.167-173
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• 2023

X-ray general radiography is the simplest and most important one to get a lot of information. Nevertheless, current x-ray general radiography does not observation in-depth observation. Information about the anatomy of the human body and changes in disease in x-ray general radiography can be obtained but it is difficult to determine the size and shape of the actual lesion due to the disadvantage of expanding the image. In this study, PA and LAT images were acquired and cancer magnification was calculated in the images by measuring the distance of cancer samples. By adjusting the magnification the actual cancer length and thickness were measured and compared with the CT image and the actual cancer sample size. After the PA and LAT images of the inserted 6.0 mm cancer sample were obtained and the magnification was corrected, the length was 5.9 mm and the thickness was 6.1 mm. This value was measured similarly to the actual. The problem of obtaining the magnification that needs to know the actual length from the detector to the cancer sample was secured by obtaining the magnification through PA and LAT images and it is possible to accurately measure the cancer sample size. X-ray general radiography may provide useful information in situations where CT imaging is difficult.