• Journal of the East Asian Society of Dietary Life
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• v.16 no.1
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• pp.54-64
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• 2006

The traditional Korean diet, which is high in rice and vegetables, is fast being replaced by a Western style diet as the standard of living goes up. In addition to this, cigarette smoking has taken on serious proportions, especially amongst those of the younger generation. Because Seoul (and it's surrounding areas) is the hub of Education and Business, it is densely populated and heavily polluted Consequently health-related issues and diseases are starting to resemble those prevalent in Western communities. Historically, stomach cancer was the #1 killer-disease in Korea, but nowadays lung cancer ranks either 1st or 2nd on the list of killer-disease in Korea. This is presumably due to the lethal combination of heavy smoking and pervasive air pollution. Despite these disquieting facts, almost no study had been made of the nutritional patterns and dietary habits of smoking and non-smoking young adults in the Seoul area. Therefore the purpose of this study is to compare the dietary and nutritional patterns of young smokers with those of young non-smokers in and around Seoul. This is done with regards to their eating habits and lifestyles, as well as the dietary components that contribute towards maintaining good health. The results showed that compared to non-smokers, smokers manifested irregular eating patterns and also tended to overindulge on fast- or junk foods. In contrast to this, non-smokers enjoyed a healthier diet, which was high in brown rice, grains, legumes, fresh fruit and vegetables, and 'kimchi'. Amongst the male subjects of this study, it was found that smokers consumed significantly less vitamin $B_2$, calcium, and phosphorous than non-smokers. It was also established that in general, stress-generated smoking habits were formed during the high school years of the younger generation. In conclusion: Because smokers maintain a less healthy diet and life-style, it is to recommended that a 'Health Education Program' be developed which could guide young smokers into adopting better dietary habits and life styles.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.451-463
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• 2001

Following the extensive use of implant, the incidence of peri-implantitis increases. Guided bone regeneration has been used for the optimal treatment of this disease. Because implant surface was contaminated with plaque and calculus, cleaning and detoxification were needed for the reosseointegration when guided bone regeneration was performed. Various mechanical and chemical methods have been used for cleaning and detoxification of implant surface, air-powder abrasive and oversaturated citrate were known to be most effective among these methods. However, these methods were incomplete because these could not thoroughly remove bacteria of implant surface, moreover deformed implant surface. Recent studies for detoxification of the implant surface using laser were going on, $CO_2$ laser and Soft Diode laser were known to be effective among these methods. The purpose of this study was to obtain clinical guide by application these laser to implant surface. 15 experimental machined pure titanium cylinder models were fabricated. The $CO_2$ laser treatment under dry, wet and hydrogen peroxide condition or the Soft Diode laser treatment under Toluidine blue O solution condition was performed on the each of models. Each groups were examined with SPM and SEM to know whether their surface was changed. The results were as follows : 1. Surface roughness and surface form weren't changed when $CO_2$ laser was usedunder dry condition(P>0.05). 2. Surface roughness and surface form weren't changed when $CO_2$ laser was used under wet condition(P>0.05). 3. Surface roughness and surface form weren't changed when $CO_2$ laser was used under hydrogen peroxide condition(P>0.05). 4. Surface roughness and surface form weren't changed when Soft Diode laser was used under toluidine blue O solution condition(P>0.05). From the result of this study, it may be concluded that the $CO_2$ laser having relatively safe pulse mode and the Soft Diode laser used with photosensitizer can be used safely to treat peri-implantitis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.4
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• pp.535-543
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• 2019

This study examined the empirical meaning of skylight in underground space, and for this purpose, 29 questions were drawn, consisting of technical performance, functional performance, and behavioral performance. In addition, under the assumption that the meaning of the skylight will be clearly revealed through the comparison between the underground streets with and without the skylight, three underground streets with the skylight and three underground streets without the skylight of Japan were selected as the subjects of the study. Based on the results of the survey, descriptive statistical analysis and frequency analysis were conducted, and an independent sample T-test was conducted for each analysis, and correlation analysis was conducted to derive improvement priority. As a result of the analysis, it was found that skylight had a certain effect on the sense of time and imageability inside the underground commercial space. In addition, it was analyzed that skylight exerted important function in the qualitative aspect of underground commercial space. Lastly, the improvement rankings for three underground streets without skylight were derived in the order of sign/guide map, space diversity, maintenance, rest space, and floor design.The improvement rankings for three underground streets with skylight were drawn in order of resting space, diversity of space, temperature and humidity, air, and maintenance.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.71-78
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• 2021

Since most functions of modern aircraft are controlled by software, software errors are directly related to aircraft safety. The criterion in Chapter 15 of the MIL-HDBK-516C addresses safe development and verification of military aircraft software. As the U.S. Air Force repeatedly experienced non-compliance with Chapter 15 criterion of the MIL-HDBK-516C, it published an Airworthiness Circular (AC-17-01) as a guide to meeting the criterion. In this paper, Chapter 15 of MIL-HDBK-516C, AC-17-01 and the SW Qualification Guideline (DO-178C) as applied by the Federal Aviation Administration are compared and analyzed. For the analysis, a matching ratio formula between the MIL-HDBK-516C criteria specified in AC-17-01 and the DO-178C specified in MIL-HDBK-516C criteria is defined. The sections that satisfy MIL-HDBK-516C criterion are derived when AC-17-01 or DO-178C matches. Based on the analysis results, the aircraft software development process is established and examples of application of Chapter 15 of MIL-HDBK-516C are addressed.

• Clean Technology
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• v.29 no.4
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• pp.305-312
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• 2023

Due to the strengthening of environmental requirements, aging denitrification facilities need to improve their performance. The present study aims to suggest the possibility of improving performance using computational analysis techniques. This involved modifying both the geometric design and the operating conditions, including the flow path shape of the equipment such as the inlet guide vane and the curved diffusing part, and the flow control of the ammonia injection nozzle. The conditions presented in this study were compared with existing operating conditions in terms of the flow uniformity, the NH₃/NO molar ratio of the mixed gas flowing into the catalyst layer, and the total pressure drop of the facility. The flow field applied in the computational analysis ranged from the outlet of the economizer in the combustion furnace to the inlet of the air preheater, the full domain of the denitrification facility. The performances were derived by solving the flow fields using ANSYS-Fluent and the injection amount of ammonia was adjusted for each nozzle using Design Xplorer. Compared to the denitrification performances of the equipment currently in operation, the conditions proposed in this study showed an improvement in the flow uniformity and NH₃/NO composition ratio by 45.1% and 8.7%, respectively, but the total pressure drop increased by 1.24%.

• Journal of Radiation Protection and Research
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• v.39 no.1
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• pp.7-13
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• 2014

Phosphate rock, phosphogypsum, and products in phosphate processing facility contain naturally occurring radioactive materials (NORM). Therefore, they may give rise to enhanced radiation dose to workers due to inhalation of airborne particulates. Internal dose due to particle inhalation varies depending on particle properties. The objective of the present study was to characterize particle properties at the largest phosphate processing facility in Korea. A cascade impactor was employed to sample airborne particulates at various processing areas in the plant. The collected samples were used for characterization of particle size distribution, particle concentration in the air, and shape analysis. Aerodynamic diameters of airborne particulates ranged 0.03-100 ${\mu}m$ with the highest concentration at the particle size range of 4.7-5.8 ${\mu}m$ (geometric mean = 5.22 ${\mu}m$) or 5.8-9.0 ${\mu}m$ (geometric mean = 7.22 ${\mu}m$). Particle concentrations in the air varied widely by sampling area up to more than two orders of magnitude. The large variation resulted from the variability of mechanical operations and building ventilations. The airborne particulates appeared as spheroids or rough spherical fragments across all sampling areas and sampled size intervals. Average mass densities of phosphate rocks, phosphogypsums, and fertilizers were 3.1-3.4, 2.1-2.6, and 1.7 $gcm^{-3}$, respectively. Radioactivity concentration of uranium series in phosphate rocks varied with country of origin, ranging 94-866 $Bqkg^{-1}$. Among the uranium series, uranium was mostly concentrated on products, including phosphoric acid or fertilizers whereas radium was concentrated on byproducts or phosphogypsum. No significant radioactivity of $^{226}Ra$ and $^{228}Ra$ were found in fertilizer. However, $^{40}K$ concentration in fertilizer was up to 5,000 Bq $g^{-1}$. The database established in this study can be used for the accurate risk assessment of workers due to inhalation of airborne particles containing NORM. In addition, the findings can be used as a basic data for development of safety standard and guide and for practical radiation safety management at the facility.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.5-11
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• 2002

In this study, new development of natural ventilation window was accomplished to control environment of greenhouse with no use of farced ventilation during hot season. The ventilation effect of developed ventilation window was investigated in experimental greenhouse which was designed using side wall panel and folding type panel fur natural ventilation. Folding panel type ventilation window was designed to open upper part of the side wall and top of the roof using two hinges which are located bottom of the side wall and the roof panel to grab one side of each panels and guide the other side along with the guidance rail. Developed ventilation window has top ventilation part with maximum moving distance X=ι (1-cos$\theta$)=848.5 mm and side ventilation part with maximum moving distance Y=ι/2 $\times$sin$\theta$=1,184.4 mm at 45$^{\circ}$ of theoretical opening angle. It took 4.5 minutes to open roof vent fully and temperature at 1.2 and 0.8 m height decreased after 1 minute from starting opening and became equilibrium state maintaining 3-4$^{\circ}C$ difference after 2 minutes from complete opening. Air exchange rate was 15.2~39.3 h$^{-1}$ which was more than 10~15 h$^{-1}$ of continuous type and Venlo type greenhouse. The descent effect of temperature by ventilation windows was two times higher than Venlo type greenhouse.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.93-106
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• 2011

Republic of Korea officially announced its mid term reduction target which reduce about 30% of BAU GHG emission by 2020 in the 15th meeting of UNFCCC(COP 15) held in Copenhagen, Denmark 2009. To achieve this goal, it is necessary to understand the serious of climate change and take part in GHG reduction not only industry but also the nation. However, such positive participation in green life which may cause inconvenient of the life of the people. It should be accomplished with providing reliable information. This study suggests the scientific potentialities of GHG emission by guideline on low carbon life and green life to form and change a lifestyle suitable for coping with climate change. And also, this study quantitate the GHG reduction which may reduce demand for air conditioning by cool biz and warm biz. In Korea, this campaign has become known as 'CoolMaebsi' by Ministry of Environmental of Korea. 'CoolMaebsi' is a compound word of 'Cool' which means feel refreshed, and 'Maebsi' is a Korean word which means attire. Though this campaign is effective and significant to reduce the GHG emission yet there were no study on quantitative analysis. Therefore this study calculated reduced energy consumption and potential GHG emission by measuring variation of skin temperature. As the result, wearing warm biz and cool biz have an effect of reducing not only the energy consumption but also GHG emission. To achieve the low carbon society, it is necessary to improve the energy saving system and introduce the policy which guide to change a life style.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.576-585
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• 1991

General procedures of seed preparation as conventional guide had been established in China before most of Korean literature documented them. ‘Chwijongbeob’ (method of seed select) was to select good quality of seeds and to discard the rest. In ‘Seonjongbeob’ (method of seed grading) although China employed only ‘Sooseonbeob’ (method of seed select with water), but seeds were selected in order of selection of seeds by winds, selection of seeds by sieve and selection of seed with water in Korea. As compared with the recent techniques, those methods were perfect techniques for selection of good quality seeds of rice, except for method of seed selection by salt water was developed. The method for measurement of seed moisture, and for measurement of melted snow, spoiled urine and extracted juice by boiling water with the bone of livestock were originated from ancient China. The farming books in Korea were more or less followed the above methods. However, these techniques were complicated and impractical interms of validity and rationality. Also, it is judged that these tchniques are more appropriate in dry areas and alkaline soil of China rather than in Korean conditions. The plowing is a work to begin farming, and is operated for air ventilation between atmosphere and earth. Also, this techniques was adopted in the farming books from the early to the late Chosun dynasty without changes. Fields were deep-plowed in the first, in fall (or in spring) and for cultivation, and were shallow -plowed in the second, in spring (or in summer) and in intertillage. The former was for water reserve and land preparation, and the later was for weed control with intertillage. However, plowing in fall which was different from fallowing in dry areas, was recommended in Korea (Jikseol). but was not practiced in Sejongsilrok. This was changed with time, and plowing for cultivation in Korea was interrelated with use of green manure crops, method of plowing of upseting plough, method of manure practice and sometimes dry plowing. In addition, until the 15th century method of using a kind of plowing-tool made of log as farm tools was created to support reclamation for enlargement of farm land in mountaineous and coastal areas. For desolate farm lands by many internal and external disturbances, one tried to recover yield ability by increasing labor productivity from the 17th or 18th century. To do this, ‘Banjongbeob’ (culture method by upset plowing weed control) and ‘Hwanubeob’(culture method by firing weed control) which were cultural methods of ancient China were readapoted but the results were not clearly informed. Also, the reality of those was reexamined in the end of the Chosun dynasty.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.2
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• pp.99-106
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• 2007

Purpose: The patient's position and anatomy during the treatment course little bit varies to some extend due to setup uncertainties and organ motions. These factors could affected to not only the dose coverage of the gross tumor but over dosage of normal tissue. Setup uncertainties and organ motions can be minimized by precise patient positioning and rigid immobilization device but some anatomical site such as prostate, the internal organ motion due to physiological processes are challenge. In planning procedure, the clinical target volume is a little bit enlarged to create a planning target volume that accounts for setup uncertainties and organ motion as well. These uncertainties lead to differences between the calculated dose by treatment planning system and the actually delivered dose. The purpose of this study was to evaluate the differences of interfractional displacement of organ and GTV based on the tomoimages. Materials and Methods: Over the course of 3 months, 3 patients, those who has applied rectal balloon, treated for prostatic cancer patient's tomoimage were studied. During the treatment sessions 26 tomoimages per patient, Total 76 tomoimages were collected. Tomoimage had been taken everyday after initial setup with lead marker attached on the patient's skin center to comparing with C-T simulation images. Tomoimage was taken after rectal balloon inflated with 60 cc of air for prostate gland immobilization for daily treatment just before treatment and it was used routinely in each case. The intrarectal balloon was inserted to a depth of 6 cm from the anal verge. MVCT image was taken with 5 mm slice thickness after the intrarectal balloon in place and inflated. For this study, lead balls are used to guide the registration between the MVCT and CT simulation images. There are three image fusion methods in the tomotherapy, bone technique, bone/tissue technique, and full image technique. We used all this 3 methods to analysis the setup errors. Initially, image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours and then the radiation therapist registered the MVCT images with the CT simulation images based on the bone based, rectal balloon based and GTV based respectively and registered image was compared with each others. The average and standard deviation of each X, Y, Z and rotation from the initial planning center was calculated for each patient. The image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours. Results: There was a significant difference in the mean variations of the rectal balloon among the methods. Statistical results based on the bone fusion shows that maximum x-direction shift was 8 mm and 4.2 mm to the y-direction. It was statistically significant (P=<0.0001) in balloon based fusion, maximum X and Y shift was 6 mm, 16mm respectively. One patient's result was more than 16 mm shift and that was derived from the rectal expansions due to the bowl gas and stool. GTV based fusion results ranging from 2.7 to 6.6 mm to the x-direction and 4.3$\sim$7.8 mm to the y-direction respectively. We have checked rotational error in this study but there are no significant differences among fusion methods and the result was 0.37$\pm$0.36 in bone based fusion and 0.34$\pm$0.38 in GTV based fusion.