• Applied Microscopy
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• v.37 no.3
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• pp.157-166
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• 2007

This experiment was performed to evaluate the ultrastructural responses of the absorptive cells in the appendix of the mouse, inoculated with Ehrlich carcinoma cells in the inguinal area, following administration of BCG (Bacillus Calmette-Guerin). Healthy adult ICR mice weighing 25 gm each were divided into normal and experimental groups (experimental control group and BCG treated group). In the experimental groups, each mouse was inoculated with $1{\time}10^7$ Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.5mL of saline or BCG (0.5 mL/25gm B.W.: $0.03{\times}10^8{\sim}0.32{\times}10^8CFU$) were injected subcutaneously to the animals every other day. The day following the last injection, each mouse was sacrificed. Pieces of the tissue were taken from the appendix, prefixed with 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by post-fixation with 1% osmium tetroxide solution. The ultrathin sections were stained with uranyl acetate and lead citrate. In the normal control, experimental control and BCG treated mice, general morphology of the absorptive cells of appendix were similar. But myelin figures and intramitochondrial dense granules were more frequently observed in the absorptive cells of BCG treated mice than normal control ones. Above results show that BCG did show slight ultrastructural alterations in the absorptive cell of the appendix. These results that BCG may slightly suppress function of the absorptive cells of the appendix.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.254-263
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• 2013

This study is to develop an evaluation index for infection control and to verify its validity by examining each set of weighted data collected from 121 infection control personnel at dental hospitals who agreed to the preliminary survey and advisory. The study was conducted from 14th December, 2010 to 31st January, 2011, and PASW Statistics 18.0 and AMOS 5.0 had been used for the statistical data analysis. As a result of the study, five evaluation factors with 21 sub-indicators have been identified at structural level, eight evaluation factors with 32 sub-indicators at processing level, and one evaluation fact with five sub-indicators at resulting level, total 14 evaluation factors with 58 sub-indicators throughout all levels. The path analysis added on the result that 'standard precautions ($x_1$)', 'infection control support system ($x_2$)', 'internal and external characteristics ($x_3$)' are exogenous variables that affect on other variables, and 'standard infection control ($y_1$)','Organization equipment management handwashing ($y_2$)', 'environmental infection control ($y_3$), 'personal protective equipment ($y_4$)', 'waste and laundry management ($y_5$)' are endogenous variables that are infulenced by others. The standardized metrics are more needed than anything else when examining on infection control. This study attempts to develop proper dental infection control metrics adequately adjusted for domestic circumstances, and therefore to contribute to effective systematic management and decision-making in infection control.

• Food Science of Animal Resources
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• v.32 no.2
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• pp.234-240
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• 2012

This study was conducted to examine the effects of low molecular weight gelatin hydrolysates (GH, less than 3kDa), extracted from pig skin collagen on the bone metabolism of ovariectomized (OVX) rats. The rats in the experimental groups were randomly segregated into six different treatment groups such as 1) NC, the normal rat fed AIN 93 diet (basal diet) only; 2) OC, the OVX rat fed the basal diet only; 3) GH 0.1, the OVX rat fed the basal diet with 0.1% GH; 4) GH 0.8, the OVX rat fed the basal diet with 0.8% GH; 5) G 0.1, the OVX rat fed the basal diet with 0.1% gelatin; 6) G 0.8, the OVX rat fed the basal diet with 0.8% gelatin. Body weight gain in the GH 0.1, GH 0.8, and G 0.8 was significantly higher than those in the NC and OC. Feed intake of the GH 0.1 and GH 0.8 was higher than that of the NC and OC, while no significant difference was found in feed efficiency ratio (FER). BMD of the GH 0.8 was higher than that of the OC. However, gelatin hydrolysates and gelatin resulted in higher BMC level compare to the OC. Serum HDL-cholesterol of rat fed GH and gelatin was higher than that of OC (p<0.05). LDL-C of the GH 0.1 and the GH 0.8 tended to be less than that of OC. Serum alkaline phosphatase (ALP) of the GH 0.1 was lower than that of the OC. The serum of GH 0.8 showed lower osteocalcin value than the OC (p<0.05). In addition, GOT and GPT levels significantly decreased in all treatment groups. These results indicated that gelatin hydrolysates from pig skin gelatin hydrolysates enhanced BMD and serum biochemical parameters related to bone metabolism. Therefore, the gelatin hydrolysates could be used as a beneficial material to improve bone health.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.2
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• pp.149-179
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• 2011

Statistics of aviation accident in Korea show that safety level of training flights is high. However, more than 80% of aviation accidents happen owing to human factors. And because most reasons of them are concerned with pilot error, it is very important for student pilots who will transport a lot of passengers to develop the knowledge of safety and abilities of risk management for preventing accidents. In this study, in order to investigate the Human Factors which affect safety in training student pilots for flight, verified the correlationbetween experiences of accident, the differences according to the experience level of training flight and the differences between college student pilots and ordinary student pilots on the basis of human factors that composes the SHELL models. For the study, Using SPSS 17.0, conducted Correlation Analysis, Analysis of Variance(ANOVA) and t-test. To sum up the result of this study, student pilot's ability and equipment in the cockpit are the important factors for safety when pilots are training flight. Also the analysis of the differences between human factors according to the characters of student pilots' groups shows that college student pilots are affected by immanent factors and organizational cultures. So far, there haven't been any accidents which is related with human casualties when training at the ATO(Approved Training Organization). But accidents can occur at any time and anywhere. Especially the human factors which comprises most of aviation accident have a wide reach and are impossible to be eliminated, therefore, it is best to minimize them. Because ATO is the starting point to lead the aviation industry of Korea, we will have to be aware of problems and improve education/training of human factors.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.1
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• pp.91-118
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• 2009

In the Republic of Korea, Regional Airlines from Jeju Air and Hansung Airlines have recently entered the domestic market to compete with the existing Legacy Airlines. In addition many of newly established regional low cost carriers like Air Busan, JeanAir, Easter Airline, are preparing to enter the jungle market. These circumstantial changes have come about as transportation competitiveness are getting weak in the market due to simultaneous expansion of surface modes such as a new opening of high-speed rail and extension of highways. The jumbled market entry by regional low cost carriers makes an enormous influence not only in managing transport network of existing carriers but also for the domestic policy of aviation authorities. It is too early to judge whether they would succeed or not. It is necessary to analyze the network operation of these regional carriers launching domestic routes and preparing to launch short distance international routes under the rapid changing market circumstances such as introduction of KTX or decrease in domestic routes by Legacy Airlines. Many regional airlines are to launch the routes connecting Korea-China-Japan, if they could ensure long-haul international routes successfully, it would follow that the difference between Legacy Airlines and Regional Airlines would decrease more and more, which would result in appearance of the $3^{rd}$or $4^{th}$Legacy Airlines The purpose of this study is to analyze the introduction of low cost carriers by regions and economic regional carrier network for non-scheduled air transportation market by taking a look at the regional airlines transportation network in the early stage of the domestic air transport market. For this purpose, cost and profit structure and management effect of transportation cost will be analyzed by comparing the presently operated routes of regional airlines with those of Legacy Airlines. And also demonstrative analysis demanded by the actual market will be achieved through surveys from experts, the actual airlines and travel agencies to build up transportation network.

• Applied Microscopy
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• v.37 no.1
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• pp.23-33
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• 2007

The lacrimal gland are compound tubule-acinar glands. The main lacrimal function is the production of the aqueous layer, the thickest and major constituent of the precorneal tear film. The lacrimal gland also has an important function in the defense system of the ocular surface, forming a part of the conjunctival-associated hymphoid tissue. The ultrastructural characteristics of the lacrimal gland of the rabbit were described. The lacrimal tissues of rabbits were processed through the conventional techniques for transmission electron microscopy. The secretory portions consisted of three cell types: 1. Serous cells with electron dense secretory granules. 2. Seromucous cells containing variable moderately electron dense secretory granules with flocculent material. 3. Mucous rolls containing mucous secretory granules. The serous cells were situated at the basal portion of acini, and they contained electron dense granules of variable densities and sizes. The seromucous cells contained a few protein secretory granules and more mucous secretory granules. The mucous cells contained even fewer protein secretory granules and exclusively mucous secretory granules. The epithelium of the intralobular ducts showed secretory granules, junctional complexes, and large basolateral intercellular spaces with lateral folds. These study might be helpful in determining inter-relationships, similarities and differences among the orbital glands of various physiological or pathological conditions.

• Journal of Conservation Science
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• v.31 no.1
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• pp.37-46
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• 2015

In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.

• Journal of radiological science and technology
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• v.36 no.2
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• pp.123-129
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• 2013

This study investigated the rate of setup variance by the rotating unbalance of gantry in image-guided radiation therapy. The equipments used linear accelerator(Elekta Synergy TM, UK) and a three-dimensional volume imaging mode(3D Volume View) in cone beam computed tomography(CBCT) system. 2D images obtained by rotating $360^{\circ}$and $180^{\circ}$ were reconstructed to 3D image. Catpan503 phantom and homogeneous phantom were used to measure the setup errors. Ball-bearing phantom was used to check the rotation axis of the CBCT. The volume image from CBCT using Catphan503 phantom and homogeneous phantom were analyzed and compared to images from conventional CT in the six dimensional view(X, Y, Z, Roll, Pitch, and Yaw). The variance ratio of setup error were difference in X 0.6 mm, Y 0.5 mm Z 0.5 mm when the gantry rotated $360^{\circ}$ in orthogonal coordinate. whereas rotated $180^{\circ}$, the error measured 0.9 mm, 0.2 mm, 0.3 mm in X, Y, Z respectively. In the rotating coordinates, the more increased the rotating unbalance, the more raised average ratio of setup errors. The resolution of CBCT images showed 2 level of difference in the table recommended. CBCT had a good agreement compared to each recommended values which is the mechanical safety, geometry accuracy and image quality. The rotating unbalance of gentry vary hardly in orthogonal coordinate. However, in rotating coordinate of gantry exceeded the ${\pm}1^{\circ}$ of recommended value. Therefore, when we do sophisticated radiation therapy six dimensional correction is needed.

• Journal of radiological science and technology
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• v.39 no.1
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• pp.1-11
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• 2016

The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from $8^{\prime\prime}{\times}17^{\prime\prime}$ to $14^{\prime\prime}{\times}17^{\prime\prime}$ by 1" in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1" in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1". Organ dose difference for internal and external of collimator measured $549.8{\mu}Gy$ in the liver and $264.6{\mu}Gy$ in the stomach. There were no significant changes organ dose difference that measured $1,135.1{\mu}Gy$ in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than $9^{\prime\prime}{\times}17^{\prime\prime}$ on AP projection and $10^{\prime\prime}{\times}17^{\prime\prime}$ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.647-655
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• 2017

This study was conducted to review the mediating effects of retirement preparation in how the degree of requirements for retirement education and the degree of preparation for retirement education affects quality of life, and how the degree of participation in retirement education which is a moderating variable is moderated. The study findings show that first, in terms of the difference in quality of life across different general characteristics, those who live in a city rather than a Gun, those who had received education of graduate school or higher rather than those with an education of undergraduate university programs or lower, those who were public officers or employees of corporations rather than those who were self-employed had a higher quality of life. The group satisfied with their economic status and health status were found to be more satisfied with their quality of life. Second, a correlation analysis showed that there was a positive correlation between retirement preparation, quality of life, and degree of requirements for retirement preparation. Moreover, there was also a positive correlation between quality of life, retirement education and the degree of requirements for retirement education. There was a positive correlation between retirement education and the degree of requirements for retirement preparation. Third, participation in retirement education moderated the indirect effect that the degree of preparation for retirement education affected quality of life through the degree of retirement preparation. In other words, the degree of requirements for retirement education affects retirement preparation and affects quality of life through the indirect effects of retirement education. As such, the moderated mediating effects of retirement education on retirement preparation was found to be greater. This indicates that quality of life may also vary in accordance with the requirements for retirement education.