• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.77-82
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• 2007

In this paper, we proposed the image processing techniques for extracting the cracks in a concrete surface crack image and the enhanced Max-Min neural network for recognizing the directions of the extracted cracks. The image processing techniques used are the closing operation or morphological techniques, the Sobel masking for extracting for edges of the cracks, and the iterated binarization for acquiring the binarized image from the crack image. The cracks are extracted from the concrete surface image after applying two times of noise reduction to the binarized image. We proposed the method for automatically recognizing the directions of the cracks with the enhanced Max-Min neural network. Also, we propose an enhanced Max-Min neural network by auto-tuning of learning rate using delta-bar-delta algorithm. The experiments using real concrete crack images showed that the cracks in the concrete crack images were effectively extracted and the enhanced Max-Min neural network was effective in the recognition of direction of the extracted cracks.

• Korean Journal of Materials Research
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• v.23 no.5
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• pp.266-270
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• 2013

The hydrogen storage properties of pure $MgH_2$ were studied and compared with those of pure Mg. At the first cycle, pure $MgH_2$ absorbed hydrogen very slowly at 573 K under 12 bar $H_2$. The activation of pure $MgH_2$ was completed after three hydriding-dehydriding cycles. At the $4^{th}$ cycle, the pure $MgH_2$ absorbed 1.55 wt% H for 5 min, 2.04 wt% H for 10 min, and 3.59 wt% H for 60 min, showing that the activated $MgH_2$ had a much higher initial hydriding rate and much larger $H_a$ (60 min), quantity of hydrogen absorbed for 60 min, than did activated pure Mg. The activated pure Mg, whose activation was completed after four hydriding-dehydriding cycles, absorbed 0.80 wt% H for 5 min, 1.25 wt% H for 10 min, and 2.34 wt% H for 60 min. The particle sizes of the $MgH_2$ were much smaller than those of the pure Mg before and after hydriding-dehydriding cycling. The pure Mg had larger hydrogen quantities absorbed at 573K under 12 bar $H_2$ for 60 min, $H_a$ (60 min), than did the pure $MgH_2$ from the number of cycles n = 1 to n = 3; however, the pure $MgH_2$ had larger $H_a$ (60 min) than did the pure Mg from n = 4 to n = 6.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.1-8
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• 2017

PURPOSE: The purpose of this study was investigate the changes of gastrocnemius (GCM) muscle activity by applying different hot and cold therapeutic modalities. METHODS: A total of 20 healthy subjects were enrolled into the study. We selected transfer modalities that are frequently used in clinical settings: conduction, radiation, and convection. We performed hot pack, ice pack, and infrared therapy for 10, 20, and 30 minutes. After each application, a break was taken between each day. In addition, we performed cryotherapy for 3 min (airflow rate = $-6{\sim}-20^{\circ}C$). We measured muscle activity changes in the GCM muscle. RESULTS: For the conduction method, muscle activity significantly increased after ice pack therapy for 10 min and 20 min but decreased after hot pack therapy for 10 min and 20 min. For the radiation method, muscle activity significantly decreased after infrared therapy for 10 min and 20 min. For the convection method, muscle activity significantly increased after cryotherapy for 3 min and 10 min. There were no differences in the change of muscle activity in the conduction and radiation transfer method using heat. However, there were differences in the change of muscle activity in the conduction and convection transfer method with cold application. CONCLUSION: For a reduction in muscle activity, regardless of the transfer type, thermal application for 20 min would be effective. For an increase in muscle activity, cold pack application or cryotherapy for 20 min would be effective. This study could contribute toward therapeutic modality application in changing muscle activity.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.1
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• pp.11-18
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• 2022

Background: The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats. Methods: Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure-volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function. Results: After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5-15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Conclusion: Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.05a
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• pp.297-302
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• 2003

고압증기멸균을 통해서 변형된 키토산을 FT-IR로 분석해 봤을 때, 기존의 키토산의 형태를 유지하고 있음을 알수가 있었고 분자량을 변화 시킨 키토산을 기존의 키토산과 납 흡착실험을 통해서 제거능 비교해 볼 때 15 min > 30 min > 10 min > 5min > 60 min > 0 min 순으로 나타났다 이로써 시간별로 autoclaving처리하여 분자량을 변화시킨 키토산의 제거율이 높음을 알 수가 있었다. 그 중에서도 15 min 동안 autoclaving처리하는 것이 가장 적당한 것으로 알 수가 있었다. 중금속 제거 전후의 키토산을 SAM과 TEM을 통해서 관찰해 보았다. SAM의 경우 autoclaving처리하지 않은 키토산의 표면보다는 autoclaving처리한 키토산의 표면에 보다 많은 기공이 생겨났음을 알 수 있었으며 그로 인해서 납 중금속이 보다 많이 흡착되어 있음을 알 수가 있었다. TEM의 결과로 봤을 때 높은 고압과 온도에 의해서 키토산 고유의 물결무늬가 사라졌음을 알 수가 있었다. 납 중금속이 내부에는 흡착이 이루어지지 않고 외부에 흡착이 이루어 진 것을 볼 수가 있었다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.443-449
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• 1997

Four-dimensional response surface methodology was applied to determine the optimum preparation conditions and to monitor sensory qualities of canned oyster mushroom during preparation. The optimum preparation conditions predicted for each corresponding sensory parameter of canned oyster mushroom were 181.29 g of oyster mushroom 205.36 ml of solution and 6.49min of roasting time for color, 214.01g, 195.79ml and 5.07min for appearance, 227.71g, 224.26ml and 6.50min for flavor, 250.30g, 183.63ml and 17.32min for taste, 211.59g, 178.21ml and 17.79min for mouth-feel, 249,.02g, 188.79ml and 17.80min for overall palatability of canned oyster mushroom, respectively. The optimum conditions, which satisfied with all sensory properties of canned oyster mushroom, were 240g, 200ml and 17min for content of oyster mushroom, content of solution and roasting time, respectively. Sensory scored predicted at the optimum conditions were in good agreement with experimental ones.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1212-1218
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• 1999

This paper proposes a new multipath interconnection network(MIN) structure for improving performance which uses widely in the design of multiprocessing, ATM system and VOD server. For improving performance such as passthrough ratio and packet latency, it proposes new routing method which routes one of the collided packets into the i+1-th switching stage of the adding Banyan MIN network when it occurred collision at the i-th switching stage of the basic MIN again when they collide each other. The new improved performance MIN network has been compared with MBSF, TBSF and PBSF structured MIN network from the viewpoint of passthrough ratio and the number of switching stage vs. passthrough ratio. It is shown to improve a performance and to be a simple structure which reducing the number of switching stage of adding MIN in comparison with other structured MIN including TBSF.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.891-897
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• 2021

With the development of Amyloid PET Tracer, the accuracy of Alzheimer's diagnosis can be improved through the identification of beta-amyloid neurites. However, the long image acquisition time of 20 minutes can be difficult for the patient. PET/CT scans are sensitive to patient movement and may partially affect test results. In this study, we studied the proper image acquisition time without affecting the quantitative evaluation of the image through the list mode acquisition method according to the time of the distribution of radioactive drugs in the body. The list mode includes information about time compared to the existing frame mode, and it is easy to analyze data because it can reconstruct images about the time that researchers want. The research method obtained a reconstructed image by time using a list mode of 5min frame/bed, 10min frame/bed, 15min frame/bed, and 20min frame/bed to compare the difference between signal-to-pons take ratio (SNR) and lesion-to-pons uptake ratio (LPR) and the difference in reading time to obtain an appropriate image. As a result of quantitative analysis, when measuring in list mode, SUVmean values decreased in 6 regions of interest as the image acquisition time increased, but showed the largest difference in 5 min/bed images, followed by 10 min/bed and 15 min/bed. As a result, the difference in SUVmean values decreased. Therefore, it was found that SUVmean values at 15 min/bed did not differ enough to not affect image evaluation. There was no difference in LPR values. As a result of the qualitative analysis, there was no change in the reading findings according to the PET image acquisition time and there was no significant difference in the qualitative analysis score of the image reconstruction according to time. As a result of the study, there is no significant difference between 15 min/bed and 20 min/bed images during the ¹⁸F-flutemetamol PET/CT test, so it can be said that it is clinically useful to reduce the image acquisition time selectively using 15 min/bed via list mode depending on the patient's condition.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.367-367
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• 2000

In this paper, an Adaptive neuro-fuzzy Inference system(ANFIS) using fuzzy min-max network(FMMN) is proposed. Fuzzy min-max network classifier that utilizes fuzzy sets as pattern classes is described. Each fuzzy set is an aggregation of fuzzy set hyperboxes. Here, the proposed method transforms the hyperboxes into gaussian membership functions, where the transformed membership functions are inserted for generating fuzzy rules of ANFIS. Finally, we applied the proposed method to the classification problem of iris data and obtained a better performance than previous works.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.74-79
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• 2017

Purpose Proton therapy can deliver an optimal dose to tumor while reducing unnecessary dose to normal tissue as compared the conventional photon therapy. As proton beams are irradiated into tissue, various positron emitters are produced via nuclear fragmentation reactions. These positron emitters could be used for the dose verification by using PET. However, the short half-life of the radioisotopes makes it hard to obtain the enough amounts of events. The aim of this study is to investigate the effect of off-line PET imaging scan time on the PET image quality. Materials and Methods The various diameters of spheres (D=37, 28, 22 mm) filled with distilled water were inserted in a 2001 IEC body phantom. Then proton beams (100 MU) were irradiated into the center of the each sphere using the wobbling technique with the gantry angle of $0^{\circ}$. The modulation widths of the spread out bragg peak were 16.4, 14.7 and 9.3 cm for the spheres of 37, 28 and 22 mm in diameters respectively. After 5 min of the proton irradiation, the PET images of the IEC body phantom were obtained for 50 min. The PET images with different time courses (0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min) were obtained by dividing the frame with a duration of 10 min. In order to evaluate the off-line PET image quality with the different time courses, the contrast-to-noise ratio (CNR) of the PET image calculated for each sphere. Results The CNRs of the sphere (D=37 mm) were 0.43, 0.42, 0.40, 0.31 and 0.21 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNRs of the sphere (D=28 mm) were 0.36, 0.32, 0.27, 0.19 and 0.09 for the time courses of 0-10 min, 11-20 min, 21-30 min, 31-40 min and 41-50 min respectively. The CNR of 37 mm sphere was decreased rapidly after 30 min of the proton irradiation. In case of the spheres of 28 mm and 22 mm, the CNR was decreased drastically after 20 min of the irradiation. Conclusion The off-line PET imaging time is an important factor for the monitoring of the proton therapy. In case of the lesion diameter of 22 mm, the off-line PET image should be obtained within 25 min after the proton irradiation. When it comes to small size of tumor, the long PET imaging time will be beneficial for the proton therapy treatment monitoring.