• Polymer(Korea)
• /
• v.35 no.5
• /
• pp.488-492
• /
• 2011

Three isocyanatopropyldimethoxysilylpolydimethylsiloxanes(IDMSi-PDMS) were synthesised from the reaction of isocyanatopropyltrimethoxysilane with monohydroxyl group termainated PDMS having different molecular weight($M_n$=5000, 10000, and 20000). Then PDMS modified polyurethane hybrid elastomer(PSMPH) were prepared from the reaction of IDMSi-PDMS with ${\alpha}$, ${\omega}$-hydroxyl group terminated polyurethane. PSMPH sealant was prepared by compounding PSMPH elastomer with additives such as plasticizer, adhesion promoter, crosslinking agent, vicosity increasing agent, inorganic filler, and catalyst at room temperature under nitrogen atmosphere. The methoxy group in the PSMPH sealant should be crosslinked with the hydroxyl group in the building stone or moisture by typical sol-gel reaction. The adhesive strength of the sealant having PDMS of $M_n$=5000 showed 40.28 kg of maxium load and 20.14 kg of break load. The shrinkage rate of the sealant having PDMS of $M_n$=20000 was 5.7% as the best result. Also, their skin over time, slump, oil content after 8 days under oil soaked paper and alkaline resistance characteristics show good results.

• Acta Via Serica
• /
• v.4 no.2
• /
• pp.119-128
• /
• 2019

This paper attempts to reveal little-known pages from the history of relations between the peoples of Central Asia and Korea based on materials derived from written sources and modern scientific literature, as well as from medieval wall paintings from the early medieval Afrasiab Palace of Varhuman, the ruler of Samarkand, and from stone sculptures of Sogdian figures contained in Silla royal tombs. Korea's interest in the western lands led to its contact with Buddhism, which spread and later flourished in all three Korean kingdoms (Koguryo, Paekche and Silla). The spread of Buddhism in turn motivated a number of Korean monks to undertake pilgrimages to India via Central Asia. Hyecho, a young Silla pilgrim, left evidence of his journey via the South China Sea to India in 723 AD. Paul Pelliot discovered a report from Hyecho's journey entitled Notes on Pilgrimage to Five Regions in India (Wang Wu Tianzhuguo zhuan) in the Dunhuang caves in 1908. Hyecho's contributions are worthy of attention, substantially complementing knowledge available for this little-studied period in the history of South and Central Asia. The information contained in Hyecho's manuscript is, in fact, considered the most significant work of the first half of the 8th century. Research regarding the relationship between Central Asia and Korea remains underdeveloped. Existing historical evidence, however, including the above mentioned Samarkand wall paintings, depicts the visits of two Korean ambassadors to Samarkand, and evidence from Silla tombs suggests the presence of diplomatic relations in addition to trade between the two regions. Overall, the history of the relationship between Central Asia and Korea yields new insights into how and why these distant countries sustained trade and diplomatic and cultural exchange during this early period. Taking into account Korea's growing interest in Uzbekistan, especially in its history and culture, this article can act as a catalyst for studying the history of the two country's relations.

• Journal of architectural history
• /
• v.21 no.5
• /
• pp.19-32
• /
• 2012

The purpose of this paper is a study on the dome plan of S. M. del Fiore Church of F. Brunelleschi. The results of study are as follows: 1. The planning of floor, elevation and cross section plan of S. M. del Fiore church is basically planned by each other correlation. In particular, the octangular form of geometrical standard which is formed with altar as the center at the crossing part is important component elements which is decided by not only the dome, but form and size of the drum and floor plan form of the lantern 2. The dome which has been planned by F. Brunelleshi has completed the new dome, preserving gothic thought intended by the church plan after study on architecture of ancient Rome with Pantheon. And the dome which is a main space of church through all aspects of plan, structure, function and construction about the dome is a opportunity in the beginning of Renaissance architecture which is a new epoch and a turning point of architecture on various point of view. 3. The dome which is constructed by F. Brunelleshi has been planned through the innovative solution by the refusal of traditional semicircle form dome, centering use and creation double-shell structure form for the first time in history. And the construction of dome has been solved with the invention of various construction equipments and machineries, the stone rib planned for connection and reinforcement about shells of the octangular form, the support method for reduction the gravity of bricklayers work and the brick work of nock-patterned shape which is masonry construction method of the architecture of ancient Rome.

• Composites Research
• /
• v.24 no.6
• /
• pp.49-55
• /
• 2011

The use of advanced composite materials in main structures of military and civil aircraft has been increased rapidly because of their considerable metals in high specific strength and stiffness. However, the mechanical properties of composite materials may severely degrade in the presence of damage. Especially, the high-velocity impact such as a hailstorm, and a small piece of tire or stone during high taxing, can cause considerable damage to the structures and sub-system in spite of a very small mass. However, it is not easy to detect the damage in composite plates using a single sensor or any conventional methods. In this paper, the PVDF sensors and AE sensors were used for monitoring high-velocity impact damage initiation and propagation in composite laminates. The WT(wavelet transform) is used to decompose the sensor signals. In the PVDF sensor and AE sensor signal analysis, amounts of high-frequency signals are increased when the impact energy is increased. PVDF sensor and AE sensor signal appeared similar results. This study shows how various sensing techniques can be used to characterize high-velocity impact damage of advanced composite laminates.

• Journal of the Korean Geographical Society
• /
• v.51 no.5
• /
• pp.577-612
• /
• 2016

The distribution of boundary markers, set up during the Yimjin(1712) Boundary Making and Demarcation(YBMD), has less been addressed so far, although it is key material evidence on which we can reconstruct the whole processes of YBMD, together with the correction of widespread myths around YBMD. This paper aims to clarify the questions on the distribution of boundary markers associated with YBMD, built during August 1712 to September 1713, by reinterpreting the key documents of Actual Survey on them: Huh Ryang and Park Dosang(1913), Kim Woosik(1883), Lee Joongha(1885), Wu Luzhen(1907), Osone Seiji(1907), and Liu Jianfeng(1908), together with topographic maps by Japanese Imperial Army(1933), the report of expedition to Mt. Baekdu by Chungjin Teachers' College(1948), and the report of field survey by Jilin province's expedition(1957). As a result, the distribution of boundary markers built in 1712~1713 is successfully reconstructed, and summarized in the format of table and maps.

• Journal of architectural history
• /
• v.19 no.6
• /
• pp.233-250
• /
• 2010

Jukseoru as an official pavilion of the government, one of the eight sceneries in Gwndong Area, is located on the cliff over Osipcheon River. This paper interprets form and space of the pavilion with restored old life by analyzing pictures of official party in 18th century in Chosun Dynasty. Every part of the space is occupied by persons by the class and duty: the pricipal guest, nobles, subordinates, gisaengs, court musicians, and guards from the high to the low and from the inside to the outside. Applying the analysis to the Jukseoru pavilion, the noblest lord takes sit on the platform in front of folded screen at main bay under checked ceiling, enclosed by low timber beam. The next northern end bay is a place for subordinates' and servants' waiting for preparation for rice wine. Southern end entrance bay is not a result of later addition but deliberately and originally made for lower place outside the railing of wooden floor: for a waiting woman gisaeng, and subordinates. Outside under the eaves on the platform with bedrock, artificial stone and soil is a place for court musicians, subordinates, and guards. The yard in front of the building is a place for preparing meals by cookers. Every detailed ornamental form is different each other by the place for the occupied class. Existing theory tells that the building, 7 bays gable-and-hipped roof, is a result of structural extention of 2 bays at the 5 bays gabled-roof. However, through the interpretation of old pictures and application to the pavilion, the present Juseoru is not a result of later structural addition, but deliberately designed creation suited to life in hierarchical traditional society.

• The Journal of Society for e-Business Studies
• /
• v.19 no.1
• /
• pp.95-118
• /
• 2014

The information technologies industry is now experiencing a rebirth of strong stable growth. However, very few studies have examined performance implications of strategic alliance or merger and acquisition from a knowledge-based view. Furthermore, none of these studies have investigated resource complementarities and alliance or merger and acquisition motive as potential sources of firm performance. This paper extends upon current knowledge-based literature to discover and explore linkages between resource complementarities and firm performance of strategic alliances or merger acquisitions. This study finds that strategic alliance and merger and acquisition announcements have provided abnormal positive returns of production alliances and merger and acquisition. This study can be used as a stepping stone for selection of strategic alliance or merger and acquisition.

• Journal of Convergence for Information Technology
• /
• v.7 no.4
• /
• pp.11-17
• /
• 2017

As nailists do not pay much attention to development of new designs while repeating existing or variated designs, nail design is not developed further and just simple design is repeated. In this perspective, this study is to suggest nail art designs grafted on Mosaic technique using diverse objets to overcome the problems of lacking materials and design skills. For the purposes, this study analysed the concept and characteristics of Mosaic technique based on bibliographical data, Internet web-sites and previous studies, and presented 4 pieces of UV gel nail art design using diverse materials of cellophane paper, gel, hologram and stone as a convergence design. As a result, this study discovered that there is a possibility that more materials would be used and the limitation of existing nail art can be overcome through a suggestion of new convergence nail art. It is expected that further research would be conducted on satisfaction of clients in the developed skills and the result will be helpful to more sale in nail shops.

• Journal of the Korea Concrete Institute
• /
• v.14 no.1
• /
• pp.16-23
• /
• 2002

In construction field, million tons of demolished concrete are produced in korea. It is urgently needed that they are used as recycled materials in order to prevent environment pollution and gain economic profits. However, existing recycling methods of demolished concrete have their limits for wide application. They have been only focused on the burying and banking. Therefore, in this paper, physical and mechanical properties of planting concrete using construction wastes for aggregates are described in order to investigate the validities of demolished concrete as recycled aggregates. The Properties of strength and durability are tested. According to the experimental results, compressive strength and freeze-thaw resistance of planting concrete using recycled aggregates shows worse performance than those using crushed stone concrete. But, it shows positive performance on the absorption ratio and thermal conductivity. Especially, considering the side of recycling of concrete wastes, it is recommended that recycled aggregates made with construction wastes is applied to planting concrete.

• Journal of the Korea Concrete Institute
• /
• v.14 no.1
• /
• pp.41-48
• /
• 2002

In this paper, permeable polymer concretes with unsaturated polyester or vinylester resin content from 5 to 8 weight ％, resin-filler ratio of 1 : 1, sand content from 0 to 15 weight ％ and crushed stone of size 2.5∼10 mm were prepared, and tested for compressive strength, flexural strength and water permeability. The effects of the resin and sand contents on the properties of permeable polymer concrete were discussed. It is concluded from the test results that increase in the strength and decrease in the coefficient of permeability of the permeable polymer concrete arc clearly observed with increasing the resin and sand contents. The permeable polymer concrete showed compressive strength in the range of 170 to 350 kgf/$\textrm{cm}^2$ and flexural strength in the range of 40 to 90 kgf/$\textrm{cm}^2$ at coefficient of permeability from 0.1 to 1.0 cm/sec in this experiment.