• The Journal of Engineering Geology
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• v.31 no.3
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• pp.239-255
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• 2021

Kinematic analyses of magmatic intrusions and faults can provide useful information on stress conditions and chronological relationships between dike emplacement and brittle deformation events. We studied structures in rocks exposed on a coastal platform in Geoje Island off the southern Korean Peninsula because of its well-developed dikes and faults. The geology of the study area includes the Cretaceous Seongpo-ri Formation, which is composed mostly of shale, sandstone, and hornfels intruded by magmatic dikes. Most of the dikes are developed along pre-existing structural features (faults and fractures), indicating that their emplacements were structurally controlled. Because dikes commonly open along the direction of the minimum principal stress, the direction of this stress can be obtained from dike geometry and orientation through the matching of piercing points on either side of a dike. In addition, the deformed dikes can give information regarding later deformation. On the basis of the kinematic analyses, we identified five deformation events in the study area, which are kinematically related to changes of the regional maximum principal stress. Results indicate that the structures in the study area have been controlled predominantly by episodes of reactivation of the NNE-trending Yangsan strike-slip fault, located to the northeast of the study area, under different stress regimes. In a wider tectonic context, the brittle deformation of the rocks of Geoje Island was probably induced by interactions among the Philippine Sea, Pacific, and Eurasian plates, including changes in subduction parameters with respect to the latter two plates over time.

• Nuclear Engineering and Technology
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• v.55 no.11
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• pp.4181-4190
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• 2023

Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm²/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

• Korean Journal of Environment and Ecology
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• v.6 no.2
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• pp.168-179
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• 1993

Use impacts on environmental deteriorations of trail were studied on the three major trails of Sobaeksan National Park in 1992. The entire width and bare width of trail as the trail condition were significantly greater on the more heavily used trail. Maximum depth of trail was not so great in spite of steeper grade of trail in comparison with the other National Parks. Percentages of deepening. rock-exposed. diverged points as the deterioration types of trail which were surveyed at the total of 105 points were high and trail conditions were significantly different from those of non-deteriorated points. On the Ridge trail. the damaged area more severe than Class 4 reaches about 10,335$m^2$ and the deterioration is accelerated. The dominant trees of the the upper layer in trail edge vegetation are changed from Q. mongolica. Aar mono to Q. mongolica for Huibang trail. and from Pinus densiflora. Q. mongolica to P. densiflora and to Q. mongolica for Biro trail as altitude increases. Rhododendron schlippenbachii. Weigelu subsessilis. Salix hulteni. Rubus crataeglfolius were classified for tolerant species and R. coreanus. Vaccinium koreanum for intolerant species to use impacts. Highly competetive species on the Ridge trail were grouped R. schlippenbachii. W. subsessilis. Rubus crataegifolius and Symplocos chinensis for. pilosa.

• Journal of Acupuncture Research
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• v.19 no.4
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• pp.140-151
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• 2002

This study was carried to identify whether acupuncture at several meridian points can affect the human anesthesia or not through the analysis of serum intermediates, such as, melatonin, serotonin, TSH, cortisol in human serum. We investigated the effect of accupuncture on the change of serum intermediates which have frequently been made a subject of discussion owing to its hyponic and sedative properties in practice. The result obtained were as follow ; 1. Serum melatonin levels was hardly affected at 40 minutes after general acupuncture on Hab-Gog, Nae-Gwan, and the other meridian points as compared with that($5.64{\pm}1.02pg/ml$) of resting control group. But on day 1 after acupuncture, these tend to increase significantly ($7.95{\pm}2.05pg/ml$ to $8.21{\pm}1.57pg/ml$, p <0.05). On the other hand, control group under sleep showed the serum level of $7.39{\pm}1.03pg/ml$. Additional acupuncture at In-Dang induced the increased melatonin level, especially at 40minutes after acupuncture(p <0.05). 2. Serotonin level in resting control serum recorded $51.14{\pm}8.17{\mu}g/ml$. Acupuncture at determined meridian point intend to increase average level of serotonin, but not significant. However observation on day 1 after acupuncture at Hab-Gwan meridian point and under sleeping showed the significantly increased serotonin level, $74.05{\pm}35.83{\mu}g/ml$, $70.44{\pm}13.08{\mu}g/ml$, respectively. 3. TSH level in intact human serum recorded $0.85{\pm}0.24{\mu}IU/ml$. and the serum exposed to acupuncture showed the irregular pattern of TSH level in a mean range of $0.76{\pm}0.44{\mu}IU/ml$ to $1.06{\pm}0.38{\mu}IU/ml$, regardless of meridian point or time after acupuncture. 4. The values of serum cortisol in control group were $11.76{\pm}2.06{\mu}g/dl$ in resting, $7.51{\pm}2.85{\mu}/dl$ under sleep, respectively. The level of serum cortisol in 40minutes after acupuncture was markedly (p <0.05) reduced to the serum levels of $5.65{\pm}2.58{\mu}g/dl$ (Hab-Gog, Nae-Gwan), $7.58{\pm}3.21{\mu}g/dl$ (Gyo-Gam, Sin-Mun besides Hab-Gog, Nae-Gwan), $6.43{\pm}3.54{\mu}g/dl$ (In-Dang besides to Hab-Gog, Nae-Gwan), respectively, as compared with control, intending to increase a little on day 1 after acupuncture. From the above results, the analysis of serum intermediates suggest that acupunctuation at meridian points applied to at this study act upon the phase of light anaesthesia or hypnosis, at the same time affect pituitary-adrenal axis rather than hypothalamus-pituitary axis in the secretary system of hormone and also don't affect dorsal-raphe nucleus according to the observation of change transition in serum intermediates, such as TSH, serotonin, and cortisol.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.230-239
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• 2014

This study is to promote awareness to be exposed to radiation with identifying knowledge, attitudes and behavior for radiation safety management of the operating room nurse and dental hygienist. And the following results were obtained through questionnaire survey to deduct the education to prevent potential risks in advance and implication to be useful on education program. First, based on the level of knowledge for radiation safety management, 10.57 for dental hygienists, 9.55 for the nurse out of 15 points (p<0.001); based on the level of attitudes for radiation safety management, 4.64 for dental hygienists, 4.67 for the nurse out of 5 points (p<0.001); and based on the level of behavior for radiation safety management, 3.27 for dental hygienists, 2.93 for the nurse out of 5 points (p<0.001). Second, the result for checking the relation with knowledge, attitudes and behavior for radiation safety management, the knowledge of radiation safety management has correlation with attitudes and behavior for radiation safety management statistically (p<0.001).

• Journal of dental hygiene science
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• v.7 no.1
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• pp.1-7
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• 2007

This study aimed to provide basic information on dental hygienists' practicing the prevention of infections by figuring out their actual conditions in dental clinics. The subjects of the study were the dental hygienists who participated in the continuing medical education of Incheon & Gyeonggi-do association and Seoul city association in October and November 2005 and the self-administered surveys were used for the prevention of infections. The results were as below. 1. In terms of education experiences of infection prevention, those who answered "there were" were 72 persons (42.9%) and those who followed the educational route for infection prevention were "through the in-house education from the hospital" and they were 42 persons (58%), which were highest. 2. In terms of the injury experiences, those who answered "there were" were 147 persons (87.5%) and the number of annual injury out of 147 persons with injury experiences was 7.7 time. For the tools that were damaged, 125 persons (75%) damaged the "explorer," which was highest. 3. For the experiences of being infected with contagious diseases, those who answered "there were" were 6 persons (3.6%) and there were four persons for "hepatitis B", one person for "rubella" and one person for "TB." 4. The questions with high practice scores were as in the following: "2. I wash my hands after conducting medical examinations (1.86 points)," "7. I always close the lid of a shot of Novocain after doing local anesthesia (1.86 points)" and "20. I separate and collect the wastes and give them to those who treat accumulated materials (1.85 points)". Meanwhile, the questions with low practice scores were as below: "16. I change my medical gowns (doctor wears) once a day (0.24 point)" and "I wash my medical gowns every time after examining patients with contagious diseases (0.52 points)." 5. The question with high knowledge was as below: "1. The contagion during the dental treatment is determined by source of infection, infection methods, infection routes and the host that is prone to infection (0.95 point)" and the question with the lowest knowledge was "5. HBV(hepatitis B) is destroyed after adding 95oC of heat for more than 5 minutes (0.27 points)." 6. The question with the highest organization-related factors was "I am always ready to use a mask, gloves, etc. if necessary" (0.89 points)" and the question with the lowest score was "There is a guideline that I can refer when I am exposed to dangerous situations related to the contagion in my workplace (0.33 point)." 7. In terms of the equipment conditions of protectors in medical environments, 168 persons for (disposable) mask (100%), 167 persons for disposable gloves (Latex) (99.4%), which meant that most of them were equipped with them. On the contrary, 108 persons (64.3%) are equipped with the protectors for frontal faces, which is the lowest and 165 persons (98.2%) said that they had autoclave in their disinfecting and sterilizing devices.

• Korean Journal of Remote Sensing
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• v.17 no.1
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• pp.33-44
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• 2001

The paper presents several satellite models and satellite image decomposition methods for inaccessible area where ground control points can hardly acquired in conventional ways. First, 10 different satellite sensor models, which were extended from collinearity condition equations, were developed and then behavior of each sensor model was investigated. Secondly, satellite images were decomposed and also pseudo images were generated. The satellite sensor model extended from collinearity equations was represented by the six exterior orientation parameters in $1^{st}$, $2^{nd}$ and $3^{rd}$ order function of satellite image row. Among them, the rotational angle parameters such as $\omega$(omega) and $\Phi$(phi) correlated highly with positional parameters could be assigned to constant values. For inaccessible area, satellite images were decomposed, which means that two consecutive images were combined as one image, The combined image consists of one satellite image with ground control points and the other without ground control points. In addition, a pseudo image which is an imaginary image, was prepared from one satellite image with ground control points and the other without ground control points. In other words, the pseudo image is an arbitrary image bridging two consecutive images. For the experiments, SPOT satellite images exposed to the similar area in different pass were used. Conclusively, it was found that 10 different satellite sensor models and 5 different decomposed methods delivered different levels of accuracy. Among them, the satellite camera model with 1st order function of image row for positional orientation parameters and rotational angle parameter of kappa, and constant rotational angle parameter omega and phi provided the best 60m maximum error at check point with pseudo images arrangement.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.302-312
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• 2017

Objectives: In this study, an evaluation of the working environment of furnace workers was performed and the work-relatedness of the occupational diseases were examined Methods: In this study, two electric furnaces at a single casting business site producing manganese-based iron alloy were selected, and occupational exposures to hazardous substances were evaluated for furnace workers and furnace worker assistants. Results: As a result, total dust concentration were $0.407{\sim}3.001mg/m^3$ and respirable dust concentration were $0.196{\sim}0.584mg/m^3$. The highest concentration of crystalline silica was $0.079mg/m^3$ In the case of Masato and Sosuckwhoi crystalline silica, they contained 90.85% and 4.17% respectively. Manganese concentration was the highest at a $0.205mg/m^3$ maximum. The average of black carbon is $11.56{\mu}g/m^3$ and the maximum concentration is $604.23{\mu}g/m^3$. PAHs concentration was the highest at a $78.301{\mu}g/m^3$ of naphthalene. The concentration of carbon monoxide was 18.82 ppm(total average 3.89 ppm) during pouring, and the maximum is 131 ppm. The formaldehyde concentration was 0.003 to 0.007 ppm. Conclusions: It seems that conditions in the past were worse, since casting has recently been performed only twice per day for about 20 minutes, reducing the amount of pouring, and local exhaust systems have been installed one-by-one. In addition, it was judged that the past exposure levels were higher considering the points measured on the back-side due to the risk of damage to the individual samples. It was found that operators could be exposed to high concentrations of crystalline silica, and that they were also exposed to high concentrations of metal(fume) and carbon monoxide during pouring. Therefore, there is a risk that occupational diseases such as lung cancer and COPD may occur with long-term work in such a process.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.128-135
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• 2016

In the current concrete structure of the highway is still the major problem most of concrete deterioration caused by the freeze-thaw and deicing salt, which is of issues that are not completely resolved. In particular, a single freezing event does not cause much harm, durability of concrete under multi-deterioration environment by repeated freeze-thaw and deicing salt is rapidly degraded and reduce its service life. In this study, the exposure environmental condition according the regional highway points were established. The damage condition and chloride content of the concrete at general and severe environmental exposure condition were also investigated. In addition, the experimental test of chloride ion permeability, scaling resistant and freeze-thaw resistance were carried out to improve the durability of the mechanical placing concrete of subsidiary structure. According to the results of this study, in observation of concrete surface condition, the concrete exposed by severe environmental condition showed broad ranges of damage with high chloride contents. Meanwhile, the water-binder(W/B) ratio and the less water content, and fly ash concrete than the specified existing mix proportion is significantly improved the durability. Also, the optimal mix proportion derived for test is satisfied the strength and air contents, water-binder ratio, and durability criteria of concrete specifications, as well as service life seems greatly improved.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.387-413
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• 1998

Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR(Signal to Noise Ratio) and MTF(Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value(75.96dB) was obtained with cubic convolution method and the lowest SNR value(72.44dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan(P<0.05). 3. There were significant differences of SNR values between 60kVp and 70kVp in seven interpolation methods. There were significant differences of SNR values between facet model method and those of the other methods at 60kVp(P<0.05), but there were not significant differences of SNR values among seven interpolation methods at 70kVp(P>0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods (P< 0.05). 5. The speed of computation time was the fastest with nearest -neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method among seven interpolation methods.