• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.13-16
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• 1994

The porous PZT was prepared from a mixture of PZT and polyvinylalcohol (PVA ) powders by BURPS( Burnedout Plastic Sphere) technique. The dielectric and piezoelectric properties of piezoceramic/polymer composites dependent on the PVA wt. % were evaluated. The density of PZT/polymer 3-3 composites were decreased almost linearly with increasing the PVA wt. %.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.961-968
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• 2022

Rotator cuff tears are a leading cause of shoulder pain in adults. Due to the increase in social activities, the number of patients complaining of shoulder pain is increasing, and interest in shoulder diseases is also increasing. With the development of ultrasound equipment, the sensitivity and specificity of diagnosis are high, and it is used to diagnose rotator cuff tears in musculoskeletal disease. Ultrasound is recognized as a complementary method to MRI examination in rotator cuff tears. Therefore, this study aimed to find out the diagnostic usefulness of ultrasound and MRI examinations in the diagnosis of shoulder rotator cuff tears.A retrospective analysis was performed on 262 patients who were diagnosed with final rotator cuff damage by arthroscopy after completing ultrasound and MRI examinations. Sensitivity, feature, positive predictive value, image predictive value, and touch were disassembled for the test results. In addition, the degree of clavicular tear was scored and recorded in 5 stages. Ultrasound examination was similar to MRI examination results for both full-thickness and partial tears, and there was no statistically significant difference. Partial tear test results showed higher positive predictive value and accuracy than MRI test. In conclusion, ultrasound can be fully utilized as a screening test for rotator cuff disease, and it is thought that it will be selected and used clinically according to the patient's constitution and situation.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.57-61
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• 2015

Purpose We considered the correlation of Ejection Fraction (EF) which was analyzed by Multi Gated Blood Pool Scan (MUGA) and Echocardiography (ECHO) for the patients who were classified according to the condition of cardiac function. Materials and Methods We analyzed the patients (female 60) who were diagnosed with breast cancer and were examined by both MUGA and ECHO. The 30 patients (age: $58.27{\pm}13.48$) who were analyzed into less than 50% to 70% of EF were categorized as normal group and the other 30 patients (age: $53.70{\pm}8.45$) who were analyzed into less than 50% of EF were categorized as abnormal group. Statistical analysis with SPSS ver. 18 was applied. Results Each of the value of mean and standard deviation of normal group was $66.43{\pm}5.80$ (MUGA), $60.50{\pm}4.93$ (ECHO). There was a significant difference (p<0.001). Each of the value of mean and standard deviation of abnormal group was $41.93{\pm}7.58$ (MUGA), $41.70{\pm}11.49$ (ECHO). There was no significant difference (p>0.001). In the result, all 30 cases of normal group showed the same reading. 8 out of 30 cases in abnormal group showed inconsistency of the reading. Conclusion We could confirm the correlation of the EF in MUGA and ECHO statistically. There was difference between abnormal groups from the result of reading. If we are aware of the result according to the different cardiac function categorization, MUGA and ECHO can be used as even more accurate interchangeable test.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.1
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• pp.1-6
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• 2014

Purpose: In order to know the effectiveness of ultrasonographic examination in diagnosis and follow-up evaluation for the frozen shoulder, we compared those with contralateral side in initial and after steroid injection. Materials and Methods: For the 20 unilateral frozen shoulder from July 2012 to July 2013, ultrasonographic examination was tried using reference line 1 (CBT: distance from coracoid process to LHB tendon) and line 2 (CBG: distance from coracoid process to bicipital groove). We tried 1 time steroid injection and compared the improvement in gross motion and reference line with 2 month, 4 month, and 6 month's serial ultrasonographic examination. Results: The differences on CBT line between lesion side and normal side were -5.6 mm, -5.0 mm, and -4.3 mm in neutral (Neut), external rotation (ER) and internal rotation (IR), respectively. The differences on CBG line were -6.1 mm, -4.7 mm, and -5.0 mm respectively (p<0.05). The changes in the reference line after steroid injection were evaluated at 2 month (CBT: -4.8 mm, -3.5 mm, -2.6 mm / CBG: -4.7 mm, -4.0 mm, -3.6 mm), 4 month (CBT: -4.7 mm, -3.2 mm, -1.7 mm / CBG: -4.3 mm, -3.7 mm, -1.2 mm), and 6 month (CBT: -1.1 mm, -2.9 mm, -0.5 mm / CBG: -1.2 mm, -0.7 mm, -0.9 mm). The gross motion was improved at 4 month after injection, from elevation $108^{\circ}$, ER $32^{\circ}$, IR L5 in initial to $133^{\circ}$, $42^{\circ}$, L3 respectively (p<0.05). Pain improved from 7.5 in initial to 3.0 at 2 month on visual analog scale (VAS). Conclusion: The serial examination after steroid injection revealed that the delayed improvement on reference line (6 month) compared with pain (2 month) or gross motion (4 month). Dynamic ultrasonogram was useful in diagnosis and follow-up evaluation of frozen shoulder.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.250-254
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• 2009

Purpose: Snapping triceps syndrome is dynamic condition in which medial head of triceps snaps (dislocates) over the medial epicondyle as the elbow is flexed. Materials and Methods: The symptoms are pain or snapping at the medial aspect of the elbow and/or symptoms from coexisting ulnar nerve irritation. The diagnosis can be made by dynamic ultrasonography. Results and Conclusion: And successful outcome can be archived by operative treatment, which are ulnar nerve anterior transposition and tenotomy of medial head of triceps.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1388-1401
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• 2021

Postoperative imaging of the rotator cuff may be performed routinely, even if pain or disability develops after surgery or if there are no symptoms. Postoperative images are obtained through MRI or US, and the purpose is to confirm the integrity of the restored tendon in general. Postoperative MRI has a relatively poor diagnostic accuracy compared to that of preoperative images because various materials used in surgeries deteriorate the image quality. US can dynamically check the condition of the restored tendon and avoid artifacts from the surgical instruments used for recovery. Although imaging findings are not always consistent with the clinical symptoms or prognosis, sub-deltoid fluid retention is more important for pain and functional recovery than the thickness of the reconstructed tendon. Strain elastography can also be a useful method for predicting the prognosis.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.51-62
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• 2003

We carried out studies on develop of the ultrasound tissue mimicking materials(TMM) by synthesis of polymer urethane(C, CCR, $TiO_2$, tungsten, graphite, silver type). The major finding were as follows; (1) C type TMM was shown good homogeneity, penetration, gray scale like as liver tissue and propagated speed 1,540 m/s, attenuation $0.5{\sim}0.7\;dB/cm/MHz$. (2) $TiO_2$ type TMM was shown heterogeneous dot echo pattern. (3) Silver type TMM was appear good homogeneous echo pattern like as echo texture of thyroid gland. Therefor, C type TMM will be useful for ultrasound Q/A phantom materials and previous phantom materials.

• Journal of Sensor Science and Technology
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• v.10 no.6
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• pp.286-294
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• 2001

In this study, 3-D underwater object recognition using the self-made 3-3 type composite ultrasonic transducer and modified SOFM(Self Organizing Feature Map) neural network are investigated. Properties of the self-made 3-3 type composite specimens are satisfied considerably with requirements as an underwater ultrasonic transducer's materials. 3-D underwater all object's recognition rates obtained from both the training data and testing data in different objects, such as a rectangular block, regular triangular block, square block and cylinderical block, were 100% and 94.0%, respectively. All object's recognition rates are obtained by utilizing the self-made 3-3 type composite transducer and SOFM neural network. From the object recognition rates, it could be seen that an ultrasonic transducer fabricated with the self-made 3-3 type composite resonator will be able to have application for the underwater object recognition.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.4
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• pp.78-84
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• 1996

In this study, 3-D object recognition and restoration independent of the object translation for automotive kind recognition in parking administration system using an ultrasonic sensor array, neural networks and invariant moments are presented. Using invariant moment vectors of the acquired data 16$\times$8 pixels, 3-D objects could be classified by SCL (Simple Competitive Learning) neural networks. Modified SCL neural networks using the 16$\times$8 low resolution image was used for object restoration of 32$\times$32 high resolution image. Invariant moment vectors kept constant independent of the object translation. The recognition rates for the training and the testing data were 98[%] and 95[%], respectively. The experimental results have shown that ultrasonic sensor array with the neural networks could be applied for the detection of the automobiles and classification of the automotive kind.

• Korean Journal of Medicinal Crop Science
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• v.16 no.5
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• pp.294-300
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• 2008

This study was performed to investigate the increasing of immune activities from Centella asiatica L. Urban by several solvent extraction with ultrasonification process. Ethanol extracts at $60^{\circ}C$ and associated with ultrasofication showed more 15% yield than normal $100^{\circ}C$ water extracts. And ethanol extracts showed higher yield than water extraction at each process. It can be concluded that yield due to polarity of compound in C. asiatica from HPLC peak. All of extracts from C. asiatica revealed lower cytotoxicity than 32%. The ethanol extracts with ultrasofication showed higher promotion on human B and T cell growth, about 10% compared to the control. The secretion of IL-6 and TNF-a was also enhanced as $4.86\;{\times}\;10^{-4}\;pg/cell$ and $5.73\;{\times}\;10^{-4}\;pg/cell$ each, by the addition ethanol extracts with ultrasonification to T cell. NK cell activation was improved up to 10% higher than the control, through adding the samples. It can be concluded that the ethanol extracts from C. asiatica has higher immune activities followed by ultrasonification process, possibly, by higher yield than conventional extraction process.