• The Journal of Sustainable Design and Educational Environment Research
• /
• v.19 no.4
• /
• pp.26-39
• /
• 2020

This study analyzed the usage characteristics and requirements of students who are users of the middle school education space, and the following results were obtained: First, we could see that various types of classes were needed, such as lecture-style classes, team projects, and four-person consultation and discussion classes, in a way that helped to improve the desirable teaching patterns and learning ability. Second, the place where space was used during the break and the relationship between peers, revealed that most of them were in the classroom and the hallway, and the peer group was composed of three to eight people or more, that were active with various compositions. Third, a gym, library, toilet, stairway, cafeteria, nurse's office, and teachers' room appeared in the center of the building, indicating the need for a balanced layout. Fourth, physical education (dance) rooms, audiovisual rooms (performance rooms), workshops (personal creation), snack bar, rest area, spacious indoor square, and study rooms were needed as facilities that can help learning activities other than current facilities. These outcomes show that the existing classroom layout and space composition formats require some spatial restructuring.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.28 no.2
• /
• pp.81-87
• /
• 2022

Paper is a promising alternative to petroleum-based plastic materials for sustainable packaging applications. However, paper exhibits poor gas and water vapor barrier properties, which restrict its effective application in the packaging industry. To enhance the properties of papers, sodium caseinate (CasNa)/transglutaminase (TG) coating solutions with various TG contents were prepared and coated on the papers. The chemical and morphological structures, mechanical properties, seal strength, and water vapor barrier properties of the coated papers were thoroughly investigated. The paper properties depended significantly on the chemical and morphological structures. Pristine CasNa and CasNa/TG coating solutions were evenly coated on the paper surfaces, without any cracks. The chemical structure of the CasNa/TG coated papers was slightly influenced by TG addition, resulting in increased elongation at break and enhanced water barrier properties. To promote the use of CasNa-coated papers in packaging applications, additional investigations must be performed to prevent gas and moisture permeation and enhance the mechanical strength of these papers via chemical reactions and introduction of organic/inorganic composites.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.7
• /
• pp.729-736
• /
• 2015

In this study, the effects of specimen size and side-groove on the results of the J-R test for leak-before-break (LBB) evaluation were investigated. A series of J-R tests were conducted at both RT and $316^{\circ}C$, using three different sizes of compact tension (CT) specimens machined from SA508 Gr.1a piping material: 12.7 mm-thick 1T-CT, 25.4 mm-thick 1T-CT, and 25.4 mm-thick 2T-CT with and without side-groove. The results showed that side-grooving reduced the J-R curve for all specimens and the effect of side-grooving was more significant at $316^{\circ}C$ than at RT. As the thickness of the specimens decreased and the width of the specimens increased, the J-R curve slightly decreased at RT but it increased at $316^{\circ}C$. However, the variation in the J-R curve of SA508 Gr.1a with the thickness and width of CT specimen was insignificant.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.241-246
• /
• 2008

With construction industry recession, many construction companies are increasingly conducting the development projects by themselves. However, housing projects requested by developers still stand large portion. Although many studies on feasibility analysis were released, they mainly focused on economic feasibility and lacked research on factors and criterions of overall project. Also, because previous studies overly break downed factors related to project, they rarely used in practice. Therefore, this study developed the feasibility analysis model of housing development projects to help main contractors to easily and effectively decide if it is feasible enough to promote the projects requested by developers, and verified the reliability of the model. In this study, thirty one driving factors were identified under seven different categories and the criterion of each factor was also developed. The survey on important index of each factor found "salability", "economic feasibility", "site location" and "method of raising fund" significant. 3 projects were tested by the model and its results showed resonable reliability.

• Microbiology and Biotechnology Letters
• /
• v.47 no.4
• /
• pp.603-613
• /
• 2019

This study was carried out to examine the antagonistic effect against phytopathogenic fungi of isolated strains from soil samples collected from Busan, Changwon, and Jeju Island: Botrytis cinerea, Colletotrichum acutatum, Corynespora cassiicola, Fusarium sp., Rhizoctonia solani, Phytophthora capsici, and Sclerotinia sclerotiorum. According to results of our studies, isolated strains showed an antagonistic effect against phytopathogenic fungi. Such an antagonistic effect against phytopathogenic fungi is seen due to the production of siderophores, antibiotic substances, and extracellular amylase, cellulase, protease, and xylanase enzyme activities. Extracellular enzymes produced by isolated strains were significant, given that they inhibited the growth of phytopathogenic fungi by causing bacteriolysis of the cell wall of plant pathogenic fungi. This is essential to break down the cell wall of plant pathogenic fungi and thus help plant growth by converting macromolecules, which cannot be used by the plant for growth, into small molecules. In addition, they are putative candidates as biological agents to promote plant growth and inhibit growth of phytopathogenic fungi through nitrogen fixation, indole-3-acetic acid production, siderophore production, and extracellular enzyme activity. Therefore, this study suggests the possibility of using Bacillus subtilis ANGa5, Bacillus aerius ANGa25, and Bacillus methylotrophicus ANGa27 as new biological agents, and it is considered that further studies are necessary to prove their effect as novel biological agents by standardization of formulation and optimization of selected effective microorganisms, determination of their preservation period, and crop cultivation tests.

• Journal of Korean Ophthalmic Optics Society
• /
• v.15 no.3
• /
• pp.287-291
• /
• 2010

Purpose: The aim of this study was to compare binocular functions such as near point of convergence (NPC), AC/A ratios, heterophoria, accommodation, accommodation lag, positive relative accommodation (PRA), negative relative accommodation (NRA), positive relative convergence (PRC), negative relative convergence (NRC) in normal subjects and convergence insufficiency. Methods: 86 subject (male n=45, female n=41, mean $age{\pm}SD=23.27{\pm}2.85$ years) without amblyopia, strabismus, and ocular pathology were studied. Forty three patients each group were classified as normal subjects and convergence insufficiency group based on AC/A ratio and far and near phoria. Binocular function of the two groups was measured using phoropter. r. Results: The values between normal subjects and convergence insufficiency were 5.71 cm and 7.07 cm for NPC, 5.28 and 2.81 for Heterophria AC/A, 0.92 exo/3.36 exo and 2.17 exo/10.84 exo for far and near phoria, 15.49/23.30/13.30 and 13.50/20.02/9.09 for PRC, respectively. However, there were no significant differences between normal subjects and convergence insufficiency for accommodative amplitude, accommodative lag, PRA, NRA, BI vergence test, BO vergence test, NRC. Conclusions: Both groups were a significant difference for cover test, NPC, Heterophria AC/A, far and near phoria, break point of PRC, and recovery point of PRC.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.11
• /
• pp.1132-1138
• /
• 2008

The study was carried out to investigate adsorption characteristic on hydrogen sulfide (H$_2$S) and methylmercaptan (CH$_3$SH) odor gas using the char made by a thermal decomposition of sewage sludge. The fixed bed adsorption experiments of the optimum L/D ratio could be 1.0, and adsorption capacity and break point increased with the increase of temperature. A simultaneous adsorption characteristic of H$_2$S and CH$_3$SH increased in breakthrough time and adsorption capacity more than single adsorption experiment, and CH$_3$SH had higher effective diffusivities than H$_2$S in same condition. The adsorption capacity of CH$_3$SH increased with fast velocity. When it was compared the produced absorbent with commercial activated carbon, As to adsorbent amount, it was H$_2$S 77% and CH$_3$SH 80% of commercial activated carbon.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.1
• /
• pp.50-54
• /
• 2008

There are several basic classes of recycling methods for FRP boats. The main one is 'Mechanical recycling' which involves shredding and grinding of the scrap FRP in a new product. That is one of the simpler and more technically proven methods. It recently has been reported that FRP can be recycled by separating into layers instead of crushing into powder. Many researchers should be more interested in these mechanical recycling for the eligibility. Nevertheless, because resins is very useful renewable energy, most of waste FRP regenerating methods depend on incineration (reclamation) or thermal recycling (pyrolysis). FRP is made up of laminated glass- fiber (roving cloth layer) which is also very unlikely to break into each layer. If there is an extracting method which is efficient and environment friendly removing glass fiber from waste FRP, it should also solve the another urgent problem. Laminated glass-fiber which is very limited renewable, is a serious barrier to wast FRP boat regenerating. This study is to propose a new extracting method which is efficient and environment friendly waste FRP regenerating system. And it should be applied to renewable energy applications with the waste resins of FRP. Also recycling glass fiber obtained by the separation of the roving layer from waste FRP will be consider to be useful for concrete products or structures.

• Journal of Conservation Science
• /
• v.28 no.3
• /
• pp.235-245
• /
• 2012

Nondestructive deterioration diagnosis has been carried out for the former ore dressing plant of the Yongwha mine in Yeongyang (Registered Cultural Property No. 255). Deterioration rates about organic contaminant and soil of the upper part (7 to 13 layer) indicate higher than the lower part (1 to 6 layer) of the ore dressing plants. By contrast, deterioration rates such as crack, break out and discoloration of the lower part indicate very higher than the upper part. It is estimated that the plants of the lower part that mechanical and chemical process had been done for flotation were damaged severely by physicochemical weathering with reaction of concrete and chemical solution. As results of ultrasonic velocity measurement, average p-wave velocity of plants were measured 2,462m/s (compressive strength $529kgf/cm^2$). As for the analytical results of surface contaminants and soil compositions using P-XRF, they were identical with major elements (Cu, Zn, Pb, Fe and As) of ore minerals from the Yongwha mine. Therefore, the ore dressing plant should be treated by phytoremediation with conservation because heavy metals could impinged upon plants and natural environment.

• Journal of Astronomy and Space Sciences
• /
• v.33 no.2
• /
• pp.127-135
• /
• 2016

Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.