• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.653-659
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• 2018

High-rise buildings and complex facilities are a representative urban system for the masses, and it requires an increasing role of commodity and safety. Smoke and toxic gasses can cause accidents due to fire in these systems. The purpose of this study is to develop a fiber screen material for emergency evacuation passages that can be avoided quickly and safely in cases of disasters. The fiber screen material is applicable to folding devices for emergency evacuation passages. The material is different from general steel material in that it is lightweight with less burden during storage for a long time in a roll form in a folding device. It also has an excellent secondary function in that it is less affected by radiant heat. Three kinds of fiber screen materials were selected that have good flame retardancy and post-processing characteristics. A performance evaluation was performed by a heat shrinkage test, contact heat test, combustibility test, flame retardancy test, tensile strength test, and tear strength test. As a result, the lightweight fabric shows excellent performance through post-processing, and silicone resin coating can secure safety of the pizza by the fiber screen material performance and radiant heat. The optimum post-treatment conditions were evaluated by performing a burning test after coating two kinds of glass fibers and four types of flame-retardant silicone resins with different weight and thickness.

• Journal of the Korean Wood Science and Technology
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• v.41 no.3
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• pp.234-246
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• 2013

It was found that test piece heated rapidly by 3 kW microwave for 5 minutes satisfies the targeted temperature and the percentage of moisture content, and the highest rate of weight increase is obtained in case of 120 minute immersion in the mixture of phosphates and heterocyclic compounds, from the result of such analysis as: kiln drying schedule, flame retardent by flammability test, insect resistance by termites, and permeability of combined penetrant for the wood after assigning multifunctional finish by immersing conifer structural frame, which is used for the frame work of wooden house and indoor/outdoor finishing in flame retardant and insect repellent materials mixture with the remaining heat of microwave. In addition, after a test of flame retardent treated item, it was identified that every mixture of phosphates corresponds with the standards of flame retardent, and upon investigation of moritality of 7 days after putting termites, it was showed that test piece immersed in the mixture of phosphates and heterocyclic compounds has the best characteristics, showing over 96% of high moritality. From the analysis of inward permeability of combined penetrant for the wood, it was decided that excellent performance in the flame retardent and insect resistance of the wood revealed due to full penetration of combined penetrant as it was found that combined penetrant penetrated through the whole inner cells of the wood.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.22-28
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• 2011

Purpose: This article attempted to examine how teeth for restoration is made in a clinical practice and utilize it as future educational material of teeth formation and basic data for additional research. Materials and methods: This experiment investigated the models sent to milling center for production of zirconia crowns. After scanned with Lava CAD/CAM System (3M ESPE, Seefeld, Germany), they are measured on 'ImageJ (version 1.32j, National Institutes of Health, USA)' program and compared and analyzed. Convergence angle from mesio-distal surfaces and bucco-lingual surfaces of each teeth are measured. Also, bucco-lingual diameter of the region lowered as much as 0.4 mm from incisal edge in anterior teeth except canines.(This measure is defined as the Peak 0.4) The analysis of data between each group was conducted by Windows SPSS statistic program, and was proved significant on 95% confidence level by independent t-test, one-way ANOVA and multiple analysis (Sheff${\'{e}}$ test). Results: The mean value of convergence angle was $18.67^{\circ}$ It is ranked as molar ($26.70^{\circ}$) > premolar ($16.87^{\circ}$) > anterior teeth ($14.81^{\circ}$) in the order of mesio-distal convergence angle; anterior teeth ($22.32^{\circ}$) > molar ($20.93^{\circ}$) > premolar ($15.41^{\circ}$) in the order of bucco-lingual convergence angle. The mean value of Peak 0.4 was 1.18 mm. Conclusion: Convergence angle of abutment of zirconia all ceramic crown has difference depending on the location in the arch. Due to the nature of production of zirconia all ceramic crown, convergence angle of abutment and line angle finishing degree can have an effect on internal suitability of restoration.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.72-81
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• 2004

For disposal food wastes which is about 30% portion of tatal organic wastes, vermicomposting is more environmental-friendly treatment than lanfill, incineration, etc. Recently, the interest has been increasing but there are many problems on management of vermicopmposting in field especially. This study was conducted to investigate an optimal factors, which are limit NaCl conc., the mixing rate of food wastes and casting for growth of an earthworm related to efficient vermicomposting. The limit conc. of NaCl was 0.5% and in case of feeding food wastes to earthworms as a prey only, most earthworms were dead in a few hours due to excessive degradation of organic materials and high NaCl conc. However as feeding with the casting of proper mixing rate(3:7), most earthworms were survived until finishing composting. It was investigated the increaser degree of matureness of food wastes, the higher conc. of NaCl, therefore for efficient vermicomposting, it seemed proper mixing rate of food wastes and the casting is better than matureness of food wastes. and the most suitable mixing rate was 3:7 food wastes and the casting.

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.119-127
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• 2014

This study suggests institutional and methodological approaches for preservation of South Korea's registered cultural properties of modern architecture. The suggested approaches are as follows. First, in order to improve the current registration and preservation system for cultural properties, we need to employ both structure-based classification and style-based classification. Registration criteria for modern architecture properties need to include more detailed classification in terms of their structure: brick structure, steel concrete structure and post lintel structure. In terms of construction style, the properties need to be further classified into the western style, the traditional style and the Korean-western eclectic style. In addition, protection of registered cultural properties need to be achieved through legislation of a protection system. Second, while the current system sets out six methods for preservation of registered cultural properties of modern architecture, more specific preservation methods types and plans need to be continuously introduced. In particular, as for the method of partial preservation, the method needs to be further classified based on the usage of the relevant structure so as to allow for more diverse options. First, the 'Preservation by Interior Alteration' needs to be added to the category, where the exterior is preserved as it is and the interior is preserved through alteration. Also needs to be added the preservation method where the interior space is preserved as it is and the exterior space is altered, in case the finishing materials of the exterior has deteriorated. Third, if the records on registered cultural properties of modern architecture are to provide the functions of legal evidences regarding management of architectural cultural properties, sources of knowledge required for policy making and implementation and past management record for the future, each phase needs to be closely connected in an organic manner, and we need to establish a management system and plan that go beyond the relevant organizations. Fourth, in order to preserve South Korea's registered cultural properties of modern architecture in its original state, it is imperative to prepare separate criteria for registration of technicians with expertise on modern architecture, and train experts and technicians on modern architecture, which is distinguished from the traditional architecture.

• Fire Science and Engineering
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• v.32 no.4
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• pp.50-59
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• 2018

Recently, huge life losses occurred in the elderly long-term medical care fires due to lack of escape safety. As part of the measures to enhance the effectiveness of fire escape safety, while they prolong the available safe egress time (ASET) of non fire compartments, a measure to shorten fire-fighter's arrival time by fire alarm notifying device should be implemented in these facilities. The four categories from the aspects of fire prevention/protection engineering were provided with the necessary component technologies for carrying out these helper-guided evacuations. Fire prevention engineered technology was presented by two provisions; one for ensuring small compartment sections by installing the fire rated wall between bed rooms and another for ensuring the fire retardant or/and non-flammable performance of finishing materials. Also fire protection engineered technology was presented by two items; one for imposing cooling effects by sprinklers and another for providing automatic fire alarm notifying functions to fire stations. In order to improve the escape safety of these facilities in Korea, alternative revisions may presented by considering insufficient provisions in the architectural/fire law provisions by analyzing the provisions of Japanese and domestic laws in detail.

• Fire Science and Engineering
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• v.26 no.3
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• pp.106-111
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• 2012

In this study, EIFS (Exterior insulation finish system) of exterior cladding was applied Cone calorimeter test to confirm the effect of flame retardant. As a results, the initial ignition points in accordance with the coated form and concentration of the flame retardant was delayed. But flame resistant treatment of EIFS cladding to control the fire will not affect confirmed that. In addition, EIFS that uses high-density and low-density due to difference in the density of the impact of the fire was no difference. The exterior of the ignition experiment occurred before and after 40 seconds, heat release rate to 100 seconds appears to occur about 90 % compared with the other exterior wall materials, the initial fire spread very fast was confirmed. EIFS cladding in order to prevent the spread of fire in the application of EIFS legally use is limited by the use of the building. And flame spread can be prevented, such as a vertical outer wall compartment measures are urgently needed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.263-271
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• 2014

Objectives: Along with the several cases of pulmonary disorders caused by exposure to indium that have been reported in Japan, China, and the United States, cases of Korean workers involved in processes that require handling of indium compounds with potential risk of exposure to indium compounds have also been reported. We performed biological monitoring for workers in various target manufacturing processes of indium, indium oxide, and indium tin oxide(ITO)/indium zinc oxide(IZO) in domestic factories. Materials: As biological exposure indices, we measured serum concentrations of indium using inductively coupled plasma mass spectrometry, and Krebs von den Lungen 6(KL-6) and surfactant protein D(SP-D) using enzyme-linked immunosorbent assays. We classified the ITO/IZO target manufacturing process into powdering, mixing, molding, sintering, polishing, bonding, and finishing. Results: The powdering process workers showed the highest serum indium level. The mixing and polishing process workers also showed high serum indium levels. In the powdering process, the mean indium serum concentration in the workers exceeded $3{\mu}g/L$, the reference value in Japan. Of the powdering, mixing, and polishing process workers, 83.3%, 50.0%, and 24.5%, respectively, had values exceeding the reference value in Japan. We suppose that the reason of the higher prevalence of high indium concentrations in powder processing workers was that most of the particles in the powdering process were respirable dust smaller than $10{\mu}m$. The mean KL-6 and SP-D concentrations were high in the powdering, mixing, and polishing process workers. Therefore, the workers in these processes who were at greater risk of exposure to indium powder were those who had higher serum levels of indium, as well as KL-6 and SP-D. We observed significant differences in serum indium, KL-6, and SP-D levels between the process groups. Conclusions: Five among the seven reported cases of "indium lung" in Japan involved polishing process workers. Polishing process workers in Korea also had high serum levels of indium, KL-6, and SP-D. The outcomes of this study can be used as essential bases for establishing biological monitoring measures for workers handling indium compounds, and for developing health-care guidelines and special medical surveillance in Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.11
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• pp.1510-1519
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• 2007

This comparative study analyzes and compares tight skirt sewing methods which are found in the clothing configuration reference text books available in contemporary universities and which are used in commercially-available domestic consumer products. The study samples included 15 text books and 12 tight skirt consumer products of different brands on sale at three department stores in Seoul each of which had a belt, a back-centered zipper, and back double slits. The findings of the study are summarized as follows: First, text books mainly show very basic sewing methods of using zippers on both sides of the straight-lined waist belt. This indicates that it is necessary for such methods to be complemented so that they cover a recent variety of designs, materials, and sewing machines. For consumer products, the main sewing method is to use a curved waist belt and a console zipper in silhouette running across half the hipbone. Second, consumer products employ three different types of cutting and sewing methods for putting an inseam on the center of the back slit part: to leave the whole inseam hemmed in the back center, to cut the left side of the inseam to the upper part of the back slit, and to cut the inseam to both the upper parts of the back slit. However, a method shown in most of the sampled text books is to cut the inseam of the back center to both the upper parts of the back slit. Third, the way of finishing a bottom edge hem in the text books is to do slip-stitch, herringbone stitch, and slinting hemming, in order after doing over-lock stitch, or to cut the hem on the bias and then slip-stitch, while for the consumer products the most frequently used sewing method is to finish the bottom edge hem by doing secoui-stitch. Finally, while in the text books the method of stitching darts and tucks is used for lining, the main lining method used in consumer products is to make tucks only. Also in the way of stitching the side seams of lining or the seams of the back center, there is a difference between the two sample groups of text books and the consumer products: while the former suggests using both open seams and over-lock stitch, the latter is found to finish the seams using an over-lock stitch only.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.49-65
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• 2018

The lime-soil mixture on tomb barrier (LSMB) is a type of tomb in Joseon Dynasty, which made with so-called 'Sammul' (three material compound) that mixture of lime, fine sand and yellow ocher. This study divided the tombs of the Gungri Site from Joseon Dynasty with layered wall and integrated wall according to the manufacturing types, and investigated on the basis of analysis to material characteristics and making techniques. Analytical samples were classified with lime-soil mixtures and soils, and interpreted the mixing characteristics of Sammul based on types of tomb barrier. The tomb barrier which is directly effect to control the inner environment was made with high content of lime. But the finishing or bottom layer were made with low content of lime. Overall the LSMB with integrated wall has higher content of lime and physical property than the LSMB with layered wall. The soil which was compounded as a Sammul and collected near the Gungri Site had similar with mineralogical and geochemical characteristics. Therefore, it is presumed that the fine sand and yellow ocher that made as a Sammul, were used with soil that was distributed around the site. Meanwhile, large scale limestone quarry is distributed near the site. Especially, Gungri Site has a possibility of material supply through water transport, due to the sea route from Asan bay is connected near the site. Thus, there is the possibility of transportation of lime materials from nearby quarry.