• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.69-77
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• 2014

Purpose: It aims to verify the applicability of existing age estimation methods derived from data of foreign population groups to Korean population groups. Moreover it is to suggest a new way applicable to practical age estimation on the basis of newly calculated regression formulae from data of Korean population groups and develop a subsidiarily applicable method to the existing method. Methods: Ratio of pulp cavity to dental crown was calculated by measuring the height and width of dental crowns and pulp cavities at the cervical line from 4,034 first and second upper molars, first and second upper premolars, first and second lower molars and first and second lower premolars on both left and right sides of 400 patients who had been treated in Dental Hospital of Yonsei University College of Dentistry, and regression equations were derived from the values of the ratio. Results: The equation with correlation coefficients the highest among females was as follows: age=$107.96-75.684{\times}{\sharp}17$ TCHI-$53.741{\times}{\sharp}26$ TCVI-$40.664{\times}{\sharp}45$ TCVI-$56.307{\times}{\sharp}46$ TCVI. Randomized anohter Korean female subjects (n=20) are applicated to the new equation. Mean of error of estimate is 10.322 years, standard deviation is 12.852 years. Minimum of error of estimate is 1.018 years, maximum is 21.365 years Conclusions: The error range of age estimation was found to be slightly wider when the existing regression formulae of Drusini were applied to Korean population groups. Also age estimation in females using the ratio of pulp cavity to dental crown measured with the length and width of dental crowns and pulp cavities from maxillomandibular molars was observed to have the highest reliability in the research. However, we consider that advanced equations of regression are needed to apply to both molars and premolars of males and females in the future.

• Imaging Science in Dentistry
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• v.43 no.3
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• pp.191-196
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• 2013

Purpose: This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. Materials and Methods: Two acrylic models were fabricated from a cast with normal occlusion. Straight and $75^{\circ}$ mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an $8^{\circ}$ downward tilt of the occlusal plane compared to the standard position, at an $8^{\circ}$ upward tilt of the anterior occlusal plane, and at a $10^{\circ}$ downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. Results: Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. Conclusion: Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than $10^{\circ}$ had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and $8^{\circ}$ upward tilt of the anterior part of the occlusal plane compared to other positions.

• The Journal of the Korea Contents Association
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• v.9 no.7
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• pp.37-44
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• 2009

Digital watermarking is a technology for preventing illegal copying, for protecting intellectual property rights and copyrights, and for suggesting grounds of the ownership by inserting watermarks into digital contents. Generally speaking, watermarking techniques cannot escape from data distortion and quality degradation due to the watermark insertion. In order to overcome the shortcoming, zero-watermarking techniques which do not change the original data have been proposed recently. This paper proposes CSMVQ(Chaotic SMVQ), a zero-watermarking system for SMVQ(Side Match Vector Quantization) which shows better compression ratio and quality and less blocking effect than VQ(Vector Quantization). In SMVQ, compression progresses from left top to right bottom in order to use the information of the two neighbor blocks, so it is impossible to insert watermarks chaotically. In the process of encoding, CSMVQ dynamically considers the information of the (1 to 4) neighbor blocks already encoded. Therefore, watermark can be inserted into digital contents in chaotic way. Experimental results show that the image quality compressed by CSMVQ is better than that of SMVQ and the inserted watermark is robust against some common attacks.

• Applied Microscopy
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• v.46 no.1
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• pp.27-31
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• 2016

It has been investigated what kind of characteristic X-ray in electron probe micro-analyzer (EPMA) is effective for the determination of compounds of Si series materials. After comparing the characteristic X-rays among the primary and secondary lines in $K_{\alpha}$ and $K_{\beta}$ obtained from the Si series standard samples, it was found that the secondary line of $K_{\alpha}$ exhibited the most informative spectrum although the intensity was considerably weak. As a result of analyzing the spectrum shapes of the Si series standard samples, the spectrum shape of the secondary line of $K_{\alpha}$ for SiC was different from those for other Si compounds. To grasp the characteristics of the shape, a line was perpendicularly drawn from the peak top to base line in order to divide a spectrum into two areas. The area ratio of right to left was defined to call as the asymmetry index here. As a result, the asymmetry index value of the SiC was greater than one, while those of other Si compounds were less than one. It was found from the EPMA analysis that identification of SiC became successful to distinguish from other Si compounds and this method was applicable for micro-sized compounds in a practical composite material.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1132-1137
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• 2020

In order to reduce unnecessary exposure doses generated when mammography is performed using a mammography device, a shielding ratio analysis was performed when a self-made shielding body made of bismuth was applied to the breast opposite to the imaging site. In order to determine the scattering dose of uncompressed breasts during CC and MLO tests when the right and left are compressed, the experiment is divided into when bismuth is not shielded (Not used: NU group) and when shielded (Used: U group). Proceeded. The average dose of the NU group was 9.568μSv, and the average dose of the U group was 1.038μSv. The average measured dose before and after the use of the bismuth shield was reduced by 89.15%. The use of a bismuth shield for mammography can shield scattered radiation and keep exposure to radiation to a minimum.

• Journal of Veterinary Science
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• v.23 no.6
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• pp.68.1-68.8
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• 2022

Background: Studies on anesthetized dogs regarding pulse pressure variation (PPV) are increasing. The influence of respiratory rate (RR) on PPV, in mechanically ventilated dogs, has not been clearly identified. Objectives: This study evaluated the influence of RR on PPV in mechanically ventilated healthy dogs after hemorrhage. Methods: Five healthy adult Beagle dogs were premedicated with intravenous (IV) acepromazine (0.01 mg/kg). Anesthesia was induced with alfaxalone (3 mg/kg IV) and maintained with isoflurane in 100% oxygen. The right dorsal pedal artery was cannulated with a 22-gauge catheter for blood removal, and the left dorsal pedal artery was cannulated and connected to a transducer system for arterial blood pressure monitoring. The PPV was automatically calculated using a multi-parameter monitor and recorded. Hemorrhage was induced by withdrawing 30% of blood (24 mL/kg) over 30 min. Mechanical ventilation was provided with a tidal volume of 10 mL/kg and a 1:2 inspiration-to-expiration ratio at an initial RR of 15 breaths/min (baseline). Thereafter, RR was changed to 20, 30, and 40 breaths/min according to the casting lots, and the PPV was recorded at each RR. After data collection, the blood was transfused at a rate of 10 mL/kg/h, and the PPV was recorded at the baseline ventilator setting. Results: The data of PPV were analyzed using the Friedman test followed by the Wilcoxon signed-rank test (p < 0.05). Hemorrhage significantly increased PPV from 11% to 25% at 15 breaths/min. An increase in RR significantly decreased PPV from 25 (baseline) to 17%, 10%, and 10% at 20, 30, and 40 breaths/min, respectively (all p < 0.05). Conclusions: The PPV is a dynamic parameter that can predict a dog's hemorrhagic condition, but PPV can be decreased in dogs under high RR. Therefore, careful interpretation may be required when using the PPV parameter particularly in the dogs with hyperventilation.

• The Journal of Internal Korean Medicine
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• v.28 no.3
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• pp.560-569
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• 2007

Objectives : Ryodoraku is a physiological function test using electric current, and is closely related to skin sympathetic tone. Pulse analysis is known to reflect cardiovascular reactivity. There has been no report on the correlation between ryodoraku and pulse analysis in respiratory diseases. The present study examined the diagnostic values of ryodoraku and pulse analysis for respiratory disease patients Methods : For this study, we conducted ryodoraku and pulse analysis in 103 people including 79 respiratory disease outpatients who visited the $5^{th}$ Internal Department of the Oriental Medicine Hospital of Kyung Hee University during the period from January 1, 2003 to July 25, 2006, and 24 volunteers who did not have any respiratory symptoms or disease history. The respiratory disease patients were divided into five sub-groups according to their symptom: cough-sputum group, wheezing-dyspnea group ' nasal symptoms group. cold-prone group, and fatigue prone group. We compared the disease groups with the control group in six items as follows : mean ryodoraku, mean H1, mean elastic index, the percentage of those with mean ryodoraku below $40{\mu}A$, the percentage of those with HI beyond the physiological range, and the ratio of left : right of elastic index Results and Conclusions : Ryodoraku and pulse analysis were found to have a high value as quantitative diagnosis tools reflecting individuals' weakness and firmness. The results of this research suggest that ryodoraku and pulse analysis have value as tools for diagnosing respiratory diseases.

• Korean Journal of Acupuncture
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• v.28 no.2
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• pp.49-58
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• 2011

Objectives : The purpose of this study is examining the effects of appling acupressure to acupuncture points (study group) and Interferential current therapy (ICT) to cervical region (control group) on the cerebral blood flow of 20 tension-type headache patients and the reduction of their headaches. For approaching this examination, clinical research was conducted for three weeks those two groups, each contains 10 patients. Methods : We stimulated 7 acupuncture points for headache with the acupressure (for three weeks) and applied ICT to cervical region. Also we measured VAS (visual analogue scale) and the blood flow of the vertebral arteries with TCD (transcranial doppler ultrasonography). Results : (1) When the left and right vertebral artery of study group was compared each time, significant differences were found after the 1st treatment (p<.001). Also the significant differences were found after 2, 3weeks treatment (p<.05). (2) When the Visual Analog Scale of study group were compared periodically, the significant reductions were found after the 1 week treatments (p<.05). Also the significant differences were found after 2, 3 weeks treatments (p<.001). In the case of the control group, the significant reduction were found after the 2 and 3 weeks treatments (p<.001). Conclusions : The acupressure applied to acupuncture points reduced the headache and increased the ratio of cerebral blood flow.

• Journal of Chest Surgery
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• v.18 no.4
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• pp.692-699
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• 1985

Fifty cases of Open Heart Surgery due to congenital and acquired heart disease were done using the cardiopulmonary bypass in the Department of Thoracic and Cardiovascular surgery, Chosun University Hospital from November, 1980 to June, 1985. 1. The age of the congenital heart disease was from 7 to 29 years, the mean age was 14.5 years. In the acquired heart disease, the age was from 14 to 48 years, and the mean age was 22.3 years. The ratio of male to female was about 1.8:1. 2. The number of congenital cyanotic heart disease were 7 patients, congenital acyanotic heart disease were 17 patients and acquired valvular heart disease were 26 patients. All of the acquired heart disease was one or more valve disease. 3. Preoperative symptoms of the congenital heart disease were exertional dyspnea [cyanotic 100%, acyanotic 70.6%] and palpitation [cyanotic 28.6%, acyanotic 76.1%], and the acquired heart diseases were exertional dyspnea [92.3%], palpitation [34.1 %], and chest discomfort [30.8%]. 4. The method of the myocardial protection during the cardiopulmonary bypass were mild or moderate hypothermia, intermittent coronary perfusion of the cardioplegic solution, topical myocardial hypothermia with 4oC Hartmann`s solution. 5. In the cases of the valve replacement, postoperative oral anticoagulant therapy was started at oral intake of food using the warfarin and persantin, and the prothrombin time was maintained 30-50% of control value during 3-6 months for tissue valve replacement and permanently for metal valve replacement. 6. The postoperative complications were appeared in 24 cases and the complications were wound infection, occipital alopecia, hemorrhage etc. 7. The mortality after open heart surgery was 8 percents and the cause of death was low cardiac output syndrome, right heart failure, DIC, and Left ventricle rupture.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.5
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• pp.589-596
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• 2021

In this study, the optimum gating system was designed, and the two zinc alloy worm gears were manufactured in single process by applying a symmetrical gating system with 2 runners. The SRG ratio is set to 1 : 0.9 : 0.6, and the cross-sectional shapes such as sprue, runner and gate are designed. In order to determine whether the design of the gating system is appropriate, casting analysis was carried out. It takes 4.380 s to charge the casting 100%, 0.55 to 0.6 m/s at the gates and solidification begins after the casting is fully charged. The amount of air entrapment is 2% in the left gear and 6% in the right gear. Hot spots occurred in the center hole of the gear, and pores were found to occur around the upper part of the hole. Therefore, the design of the casting method is suitable for worm gears. CT analysis showed that all parts of worm gear were distributed with fine pores and some coarse pores were distributed around the central hole of worm gear. The yield strength and tensile strength were 220 MPa, 285 MPa, and the elongation rate was 8%. Vickers hardness is 82 HV.