• Journal of the Korean Society of Radiology
• /
• v.11 no.5
• /
• pp.361-370
• /
• 2017

In the Brain MRI, RF Pulse is irradiated on the human body in order to acquire an image. At this time, a considerable part of the irradiated RF Pulse energy is absorbed as it is in our body. This will raise the temperature of the human body, but depending on the extent of exposure, it will affect the human body. The change of the SAR and the temperature of the head according to the change of the magnetic field strength is examined. And to investigate the difference in results depending on the use of dental implant. In the human head model, 64 MHz RF Pulse frequency generated from 1.5 T, 128 MHz RF Pulse frequency generated from 3.0 T, and 298 MHz RF Pulse frequency generated from 7.0 T send a frequency and experiment was performed using dental implant using the XFDTD program, we measured the SAR and body temperature changes around the head. The SAR value showed up to about 5800 times the difference at the RF Pulse frequency of 256 MHz, when with dental implant than without dental implant and as the frequency increased, the use of the dental implant increased difference in the SAR value. The change of the temperature of the head showed a temperature rise nearly 2 to 4 times when with dental implant than without dental implant. As the RF Pulse frequency increase, the SAR value increase, but the change of the temperature of the head decrease. Because of as the frequency increase, wavelength is smaller and the more the amount absorbed by the surface of the human. Physiological and biochemical studies of the human body ar necessary through studies of the presence of dental implant and the cause of reaction caused by change in the RF Pulse frequency.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.3
• /
• pp.439-447
• /
• 2003

This was performed to evaluate the inhibitory effect of laser on the growth of S. mutans. The bacterial pallets containing S. mutans KCTC 3065 were irradiated with Er:YAG laser and Nd :YAG laser by non-contact method at an intensity of 50mJ for 5 sec with the pulse repetition rates of 10Hz and 30Hz, respectively. The following results were obtained on colony count, acid producing ability, and the amount of insoluble extracellular polysaccharide synthesis. 1. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the proliferation of S. mutans the most, and the irradiation of Er:YAG also inhibited the proliferation. However, the irradiation of Nd:YAG laser alone could not inhibited the proliferation of S. mutans. The pulse repetition rate did not affect significantly on the proliferation of bacteria in overall. 2. The irradiation of Nd:YAG laser after the photosensitization with Chinese ink inhibited the acid production of S. mutans the most for a certain period of time. Er:YAG laser also inhibited acid production. When Nd:YAG laser was used alone, the acid production of S. mutans was not been inhibited. The irradiation of Nd:YAG laser after photosensitization with Chinese ink inhibited the acid production ability of bacteria the most as the pulse repetition rate increased. 3. Laser irradiation did not inhibited the synthesis of insoluble extracellular polysaccharide of S. mutans. From these results, we conclude that the irradiation of Er:YAG laser and Nd:YAG laser after photosensitization with Chinese ink would inhibit the proliferation and acid production by S. mutans, which may prevent dental caries. However, this effect does not last long time so that the laser irradiation should be repeated frequently in order to obtain clinical effect; thus, this laser irradiation would not have a clinical usefulness in preventing dental caries when used solely.

• Progress in Medical Physics
• /
• v.20 no.4
• /
• pp.269-276
• /
• 2009

Radiation treatment techniques using photon beam such as three-dimensional conformal radiation therapy (3D-CRT) as well as intensity modulated radiotherapy treatment (IMRT) demand accurate dose calculation in order to increase target coverage and spare healthy tissue. Both jaw collimator and multi-leaf collimators (MLCs) for photon beams have been used to achieve such goals. In the Pinnacle3 treatment planning system (TPS), which we are using in our clinics, a set of model parameters like jaw collimator transmission factor (JTF) and MLC transmission factor (MLCTF) are determined from the measured data because it is using a model-based photon dose algorithm. However, model parameters obtained by this auto-modeling process can be different from those by direct measurement, which can have a dosimetric effect on the dose distribution. In this paper we estimated JTF and MLCTF obtained by the auto-modeling process in the Pinnacle3 TPS. At first, we obtained JTF and MLCTF by direct measurement, which were the ratio of the output at the reference depth under the closed jaw collimator (MLCs for MLCTF) to that at the same depth with the field size $10{\times}10\;cm^2$ in the water phantom. And then JTF and MLCTF were also obtained by auto-modeling process. And we evaluated the dose difference through phantom and patient study in the 3D-CRT plan. For direct measurement, JTF was 0.001966 for 6 MV and 0.002971 for 10 MV, and MLCTF was 0.01657 for 6 MV and 0.01925 for 10 MV. On the other hand, for auto-modeling process, JTF was 0.001983 for 6 MV and 0.010431 for 10 MV, and MLCTF was 0.00188 for 6 MV and 0.00453 for 10 MV. JTF and MLCTF by direct measurement were very different from those by auto-modeling process and even more reasonable considering each beam quality of 6 MV and 10 MV. These different parameters affect the dose in the low-dose region. Since the wrong estimation of JTF and MLCTF can lead some dosimetric error, comparison of direct measurement and auto-modeling of JTF and MLCTF would be helpful during the beam commissioning.

• Korean Journal of Poultry Science
• /
• v.37 no.4
• /
• pp.383-388
• /
• 2010

The chicken eye can discriminate light color, and different light wavelengths may affect reproduction ability. This study was carried out to identify effect of monochromatic light using light emitting diode (LED) in laying hens. Chickens were exposed to white light (WL), blue light (BL), yellow light (YL), green light (GL) and red light (RL) made by using LED as well as incandescent light (IL) (control). All light sources were equalized to a light intensity of 20 lux. The results indicated that the age of first egg laying and 50 % egg laying in laying hens treated under RL is significantly younger than under other lights (P<0.05). And the ovary weight of laying hens reared under RL is significantly heavier than under other at from 16 to 20 wks (P<0.05). The largest number of eggs production was produced in a group with treated with RL by 59 wks of age compared with any other group. The egg weight of YL was greater than other treatment groups from 26 to 45 wks (P<0.05). The egg shell from hens treated with RL was the strongest and thickest at 20 wk (P<0.05). These results suggest that the egg quality of laying hens reared in different spectrum of LED can be different and RL may enhance the laying performance.

• Ocean and Polar Research
• /
• v.25 no.2
• /
• pp.183-200
• /
• 2003

In order to assess the ecological changes induced by organic pollutants of the Shihwa Lake, BPI (Benthic Pollution Index) based on the benthic faunal community was employed. It was modified from Infaunal Trophic Index (ITI), and recommended as a pollution detecting method for the environmental assessment. The BPI values were calculated from the benthos data, which were collected for three terms: in 1980, before the Shihwa Lake was built up; in 1994-1997, which the Shihwa Lake was completely isolated from the outer seawater; in 1997-1999, after inflow of the outer seawater. Since the Shihwa Dike was constructed in February 1994, the pollution intensity of the lake had been increased from the narrow and inner part of the former Gyeonggi Bay and spread fast along the coast line of the Shihwa Lake. Then, in 1996 it showed the very high BPI levels all around the Lake. This serious polluted condition had been lasted till 1997, when the inflow of the seawater was begun. In 1998, from the nearest part of the Shihwa Gate, the BPI levels gradually became low in most area of the Lake, except its inner and narrow part. These greatly lowered BPI levels mean that the seawater inflow could be assumed to affect positively in the lake. Furthermore, BPI gave the same results from the other environmental assessment based on the abundance and the species richness of macrobenthic community. It shows that BPI could be useful as an effective method to assess the marine environment and evaluate the status of environmental conditions.

• The Korean Journal of Pharmacology
• /
• v.1 no.1 s.1
• /
• pp.17-36
• /
• 1965

Besides it's all important analgesic action, morphine has, among others, hyperglycemic effect, though not important clinically, which is believed to be resulted from augmented glycogenolysis in the liver and muscles due to the increased liberation of epinephrine from the adrenal medulla upon the stimulation of the posterior part of hypothalamus. It is known that adrenergic blocking agents are acting inhibitory to this sort of hyperglycemia. Much, however, should as yet be studied for the drugs which affect central nervous system and release of endogenous catecholamine as far as their effects on hyperglycemia are concerned. Much is still not known about the effect of ginseng, which has been highly regarded in the Herb Medicine, as far as it's influence on the blood sugar is concerned. Author investigated the effects of chlorpromazine, reserpine and ginseng on epinephrine induced, and morphine-induced hyperglycemiae. Animals used in this experiment were healthy albino rabbits weighing approximately 2.0 kg of body weight and were all fasted for 24 hours, before the experiment undertaken. Blood sugar determination was carried out by Nelson-Somogy method. Results obtained are summarized as follows; 1. The groups of rabbits administered intravenously with epinephrine 0.02 mg/kg, and 0.05 mg/kg, showed marked and transient hyperglycemia within 15 minutes after injection. The maximal rate of elevation in blood sugar to the control level, were 28% and 57% respectively. The blood sugar returned to the control level within 3 hours. Thus, the hyperglycemic responses were paralleled with epinephrine doses. 2. The hyperglycemic responses by morphine were different according to the doses. The groups of rabbits in which 4 mg/kg of morphine was administered, did not show any hyperglycemic effect, but, in which 10 mg/kg of morphine administered, showed severe hyperglycemic effect, resulting in the maximal level within 2 hours after injection. The maximal rate of increasing in blood sugar ,level was 88%. Compared .with epinephrine-injected groups, morphjne-injected groups showed more persistent hyperglycemic effect, but returned to control blood sugar .level in 6 hours after injection. 3. The intravenous injection of chlorpromazine 2 mg/kg and 8 mg/kg evoked a slight, and persistent hyperglycemia. The maximal rate of increasing in blood sugar level were 15% and 23% respectively. These hyperglycemia gradually returned to the normal level in 5 or 6 hours after injection. Thus, the intensity of response was paralleled with the dose of chlorpromazine. 4. The intravenous injection of reserpine 0.2 mg/kg and 0.5mg/kg, showed the most persistent but steady elevation of blood sugar level in this experiments, resulting in the maximal level in 5 hours after injection. The maximal rate of increasing of blood sugar level were 18% and 39% respectively. 5. The blood sugar level from 24 hours to 30 hours after intraperitoneal administration of reserpine 1.0mg/kg, did not show statistically significant difference, compared with control groups. 6. The oral administration of ginseng extract 15 ml/kg did not. show any :change in blood sugar level. 7. The intravenous administration of epinephrine 0.05 mg/kg or morphine 4 mg/kg to the group pretreated with ginseng extract 15 ml/kg $20{\sim}30$ minutes before the experiment, evoked more marked hyperglycemic effect than the non-pretreated group. 8. The intravenous administration of epinephrine 0.02 mg/kg, morphine 4 mg/kg, or morphine 10 mg/kg to the groups pretreated with reserpine 0.2 mg/kg or 0.5 mg/kg $20{\sim}30$ minutes before experiment, produced more marked and persistent hyperglycemic effects than the groups injected with single epinephrine or morphine injection. 9. When epinephrine 0.05 mg/kg or morphine 10 mg/kg administered intravenously to the groups pretreated with the intraperitoneal administration of reserpine 1 mg/kg 24 hours before experiment morphine-induced hyperglycemia was inbibited, but epinephrine-induced hyperglycemia was augmented. 10. When epinephrine 0.05mg/kg or morphine 10 mg/kg administered intravenously to the groups pretreated with chlorpromazine, 2 mg/kg, 4 mg/kg, and 8 mg/kg $20{\sim}30$ minutes before the experiment, morphine-induced hyperglycemia was inbibited, but epinephrine-induced hyperglycemia was more persistent.

• Korean Journal of Cognitive Science
• /
• v.16 no.4
• /
• pp.305-322
• /
• 2005

Watermarking is a widely employed method tn protecting copyright of a digital image, the owner's unique image is embedded into the original image. Strengthened level of watermark insertion would help enhance its resilience in the process of extraction even from various distortions of transformation on the image size or resolution. However, its level, at the same time, should be moderated enough not to reach human visibility. Finding a balance between these two is crucial in watermarking. For the algorithm for watermarking, the predefined strength of a watermark, computed from the physical difference between the original and embedded images, is applied to all images uniformal. The mean brightness or contrast of the surrounding images, other than the absolute brightness of an object, could affect human sensitivity for object detection. In the present study, we examined whether the detectability for watermark noise might be attired by image statistics: mean brightness and contrast of the image. As the first step to examine their effect, we made rune fundamental images with varied brightness and control of the original image. For each fundamental image, detectability for watermark noise was measured. The results showed that the strength ot watermark node for detection increased as tile brightness and contrast of the fundamental image were increased. We have fitted the data to a regression line which can be used to estimate the strength of watermark of a given image with a certain brightness and contrast. Although we need to take other required factors into consideration in directly applying this formula to actual watermarking algorithm, an adaptive watermarking algorithm could be built on this formula with image statistics, such as brightness and contrast.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.31 no.1
• /
• pp.38-47
• /
• 2013

This study was performed in order to preserve and protect the scenic sites and surrounding environment is located in the Urban Residential Area. After classifying the type of area surrounding parcels of Seongbuk-dong is located in Seongragwon, Satisfaction Survey, scenic sites designated areas for residents living near the analyzed. Research methods, Cadastral research, literature survey, field survey, and the survey was conducted. Cultural heritage awareness about the collected questionnaires of frequency analysis, and reliability analysis for cultural heritages around satisfaction, satisfaction analysis by parcel area, parcel area for the verification of specific differences regression analysis for the full-on relationship satisfaction, one-way ANOVA was conducted for each. Overall Cultural awareness analysis results, the residence is located close to the Seoul Seonjamdanji, Seongragwon, Simujang, Sanghoe Lee Tae-Joon's houses, Seoul Hanyang castle showed that cultural heritage were know unfulfilled cultural heritage. The purpose of cultural heritage visit was to break/walks. Preservation was usually level and there is no inconvenience caused as a cultural heritage. Regulatory intensity level was usually level and showed a positive reaction to the impact of cultural heritage in Seongbuk-dong image mostly. cultural heritage have a positive impact on the image of the town. but access to cultural heritage is not easy and doesn't affect the life is expected. Overall satisfaction for cultural heritages in the surrounding space, the larger the size of the lot, and higher satisfaction. Seongbuk-dong most of the residents satisfaction was higher. Small lots of residents showed low satisfaction for safety when walking at night, heritage value rise, private ownership of heritage use, harmony with surrounding environment, Building exterior, non-physical uniqueness like culture art mental. It can be interpreted that small lots of residential environment quality is low compared to the large lots, influx of residents in other regions due to the redevelopment of one of Seongbuk-dong, private ownership of heritage use. And generally lower satisfaction on the harmonization of the facility(street lights, signs, etc.). Therefore cultural heritage signs for facility expansion, cultural educational programs, will be needed to maintain the uniqueness village when scenic sites in the city center around the area of management strategy.

• Journal of Nutrition and Health
• /
• v.34 no.6
• /
• pp.637-644
• /
• 2001

The purpose of this study was to examine the effect of exercise and diet control program on nitrogen balance in obese children. The subjects of this study were five obese boys aged from 8 to 12 participating in the control period(C) for 3 days, exercise without energy deficit period(EEN) for one week, and exercise with energy deficit period(EED) far another one week, consecutively. The intensity of the exercise was 60-70% of HRmax and the energy was restricted at 493 kcal/day. Daily mean total energy intake was 2,152 $\pm$ 138kca1, 1,861 $\pm$ 138kca1, and 1,368 $\pm$ 87kca1 for the period C, EEN and EED, respectively. The body weight for EEN and EED decreased compared with the period C by average 1.2 $\pm$ 0.2kg and 1.8 $\pm$ 0.3kg, respectively. Of the body weight loss, the fat mass decreased bur 1.0 $\pm$ 0.3kg and 1.5 $\pm$ 0.5kg and the lean body mass by 0.2 $\pm$ 0.4kg and 0.3 $\pm$ 0.4kg, respectively. Of the daily mean nitrogen consumption was 9.1 $\pm$ 0.7g, 9.1 $\pm$ 0.8g and 7.1 $\pm$ 0.5g, the daily mean nitrogen excretion from feces was 1.3 $\pm$ 0.2g, 0.9 $\pm$ 0.1g and 0.7 $\pm$ 0.1g, and from urine was 6.7 $\pm$ 0.6g, 6.6 $\pm$ 0.5g and 6.7 $\pm$ 0.6g, for the period C, EEN and EED, respectively. Daily mean nitrogen balance excluding nitrogen excretion firm feces and urine indicated + 1.1 $\pm$ 1.0, +1.6 $\pm$ 0.6 and - 0.3 $\pm$ 0.9 for the period C, EEN and EED, respectively. Despite the negative indication during EED, there was no statistical signifiranre. The daily mean creatinine excretion was 0.5 $\pm$ 0.0g, 0.7 $\pm$ 0.1g and 0.6 $\pm$ 0.0g and the creatinine-height index(CHl) was 85.1 $\pm$ 6.7%, 83.8 $\pm$ 6.6% and 81.0 $\pm$ 6.5%, for the period C, EEN and EED, respectively, indicating little significant difference among the periods. Taking above results into consideration, it seems the exercise program conducted for this study did not substantially affect the nitrogen balance of the obese children, and may be used far the body weight control. Howeever, the adequacy of the energy restriction and amount of exercise applied to this study need to be further investigated as the nitrogen balance indicated negative and increasing tendency of the creatinine excretion showed during the EED compared with period C, despite the statistical insignificance.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 2000.09a
• /
• pp.201-210
• /
• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mats. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributons. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks dial not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the $K_{I}$ vague increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.s.