• Journal of Korean Association for Spatial Structures
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• v.20 no.3
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• pp.63-70
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• 2020

Tomb of King Muryeong, located in Sonsan-ri, was found vulnerable due to leakages during since the summer of 2016. This research aims to evaluate structural safety of the Tomb under the tumulus. Site surveys were conducted to find vulnerable inner parts. Structural safety assessment is presented based on both site survey results and analytical results obtained through FEM analysis using the ANSYS program. The underground structure was explicitly modeled to focus on two types of loadings: design loads and actual gravity loads. In general, the tomb does not show any critical deflection increase or damage through the analytical investigation. However, maintenance through continuous monitoring is necessary to prevent severe deflections and stress concentrations since the rigidity of the tomb materials are very vulnerable and likely to be reduced due to prolonged weathering and continuous rain leakage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.62-65
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• 2010

ITS(Intelligent Transportation System) is in order to better operate the public transportation. The thesis purpose to introduce how does city buses and underground vehicles input in server-side controls to connecting these two parts, that achieve share information between them. Ready provision of reliable, up-to-date and accurate transport information contributes towards efficient road use, better traffic flow, greater road safety and improved accessibility and promote efficiency in the city.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.149-153
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• 2005

We have investigated thermal properties showed by changing the content of carbon black which is the component parts of semiconductive shield in underground power transmission cable. Specimens were made of sheet with the nine of those for measurement. Heat capacity (${\Delta}$H), glass transition temperature (Tg) and melting temperature (Tm) were measured by DSC (Differential Scanning Calorimetry). The ranges of measurement temperature were from -100($^{\circ}C$) to 100($^{\circ}C$), and heating rate was 4($^{\circ}C$/min). And then thermal diffusivity was measured by LFA 447. The dimension of measurement temperature was 25[$^{\circ}C$]. Glass transition temperature of specimens was showed near -25[$^{\circ}C$] and the heat capacity and the melting temperature from the DSC results were simultaneously decreased according to increasing the content of carbon black, while thermal diffusivity was increased according to increasing the content of carbon black. Because ionic impurities of carbon black having Fe, Co, Mn, Al and Zn are rapidly passed kinetic energy increasing the number of times breaking during the unit time with the near particles according to increasing vibration of particles by the applied heat energy.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.154-160
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• 2005

We have investigated thermal properties showed by changing the content of carbon black which is the component parts of semiconductive shield in underground power transmission cable. Specimens were made of sheet with the nine of those for measurement. Density of specimens was measured by density meter, and then stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400(Kgf/$cm^2$) and 600[$\%$]. In addition, tests of stress-strain were progressed by aging specimens at air oven. Finally surface profile was shown in order to looking for protrusion of specimens by using smoothness tester. Density was highly measured according to increasing the content of carbon black from this experimental result, and stress was decreased, while strain was increased according to increasing the content of carbon black. And stress-strain were decreased some after aging because of oxidation reaction of chemical defect. Lastly surface of specimens smoothed generally.

• Steel and Composite Structures
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• v.22 no.5
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• pp.1039-1054
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• 2016

This paper presents the dynamic characteristics analysis of the purlin-sheet roofs by the random vibration theories. Results show that the natural vibration frequency of the purlin-sheet roof is low, while the frequencies and mode distributions are very intensive. The random vibration theory should be used for the dynamic characteristics of the roof structures due to complex vibration response. Among the first 20th vibration modes, the first vibration mode is mainly the deformations of purlins, while the rest modes are the overall deformations of the roof. In the following 30th modes, it mainly performs unilateral local deformations of the roof. The frequency distribution of the first 20th modes varies significantly while those of the following 30th modes are relatively sensitive. For different parts, the contributions of vibration modes on the vibration response are different. For the part far from the roof ridge, only considering the first 5th modes can reflect the wind-induced vibration response. For the part near the ridge, at least the first 12 modes should be considered, due to complex vibration response. The wind vibration coefficients of the upwind side are slightly higher than that of the leeward side. Finally, the corresponding wind vibration coefficient for the purlin-sheet roof is proposed.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.174-179
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• 1991

Patterns of ginseng damage by larvae of Holotrichia diomphalia Bates in spring were investigated in 3rd year ginseng fields from 1986 to 1990. Ginseng damages were more serious in outer areas than inner areas of ginseng fields, which seemed to be due to nocturnal migration behavior of adult females. Damaged parts of 3rd year ginseng plants due to 3rd instar larvae were top, middle, bottom or whole of main roots, and rarely underground stems. Mean inhabitation depth of 3rd instar larvae were 3.2cm, 5.6cm, 6.6cm and 4.9cm in 1st, 2nd and 3rd year ginseng fields and mugwort fields, respectively. Larval feeding damage of ginseng in spring oc¬curred mainly from mid-May to early July and appeared to decrease temporarily when rainfalls increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.236-237
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• 2006

We have investigated volume resistivity showed by changing the content of Carbon nanotube and carbon black which is the component parts of semiconducting shield in underground power transmission cable. Specimens were made of sheet form with the six of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the preheated oven of both $23{\pm}1[^{\circ}C]$ and $90{\pm}1[^{\circ}C]$. The volume resistivity decreased by adding Carbon nanotube and carbon black. Also the volume resistivity had different properties because of PTC/NTC tendencies at between $23[^{\circ}C]$ and $90[^{\circ}C]$. We experimented with electric properties of semiconducting components with fewer Carbon nanotube than carbon black.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.118-123
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• 2000

This study was conducted to determine the appropriate fertilization level for growing one year old rhizome of Atractylodes macrocephala KOIDZ. According to N and K amounts were increased, the growth of above-ground parts was decreased but P was increased at this time. Based on N-P-K levels, application of 8-9-3 kg/10a was the most effectiveness for the growth of above-ground part, and 8-3-3 kg/10a for that of underground part. It can be estimated that 6-4-6 kg/10a treatment based on N-P-K may be the optimum fertilization level to obtain the highest yield of Atractylodes macrocephala KOIDZ using one year old rhizome.

• Geomechanics and Engineering
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• v.18 no.3
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• pp.267-275
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• 2019

Tabriz is a large Iranian city and the capital of the East Azerbaijan province. The bed rock of this city is mainly consisted of marl layers. Marl layers have some outcrops in the northern and eastern parts of city that mainly belong to the Baghmisheh formation. Based on their colors, these marls are classified into three types: yellow, green, and gray marls. The city is developing toward its eastern side wherein various civil projects are under construction including tunnels, underground excavation, and high-rise building. In this regard, the swelling behavior assessment of these marls is of critical importance. Also, in lightweight structures with foundation pressure less than swelling pressure, several problems such as walls cracking and jamming of door and windows may occur. In the present study, physical properties and swelling behavior of Baghmisheh marls are investigated. According to the X-ray diffractometer (XRD) results, the marls are mainly composed of Illite, Kaolinite, Montmorillonite, and Chloride minerals. Type and content of clay minerals and initial void ratio have a decisive role in swelling behavior of these marls. The swelling potential of these marls was investigated using one-dimensional odometer apparatus under stress level up to 10 kPa. The results showed that yellow marls have high swelling potential and expansibility compared to the other marls. In addition, green and gray marls showed intermediate and low swelling potential and swelling pressure, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.573-578
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• 2019

Recently, the development of indoor positioning technology, base station positioning, Wi - Fi positioning, and Bluetooth beacon positioning technology have been introduced in buildings and underground space. This paper introduces a technique that enables user-oriented ultra-high precision positioning by adopting a lenticular positioning technology, which is a method in which a user directly locates a user's moving line based on a provider-oriented positioning system and service. Through the study on the implementation of coverage using lenticular stickers, we will discuss how to implement coverage of lenticular stickers, which is one of the most important parts of lenticular positioning technology.