• Journal of Environmental Impact Assessment
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• v.22 no.4
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• pp.303-317
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• 2013

The purpose of this study is to offer the raw data for restoration and management of trails by assessing the physical environments, the types of deterioration and the naturalness on trails located in the Sogeumgang, Hwarang and Seoak districts of Gyeongju National Park, Korea. The Sogeumgang was 5.9m, 1.1m of the Hwarang and 1.8m of the Seoak district in trail width. In the bared width of trail, the Sogeumgang was 3.9m, 0.9m of the Hwarang and 1.7m of the Seoak district. In the depth of erosion, the Sogeumgang was 37.1cm, 14.2cm of the Hwarang and Seoak district. The Sogeumgang was $16.8^{\circ}$, $13.1^{\circ}$ of the Hwarang and $12.2^{\circ}$ of the Seoak district in longitudinal slope. In the left and right of transect slope, the Sogeumgang was $18.3^{\circ}$ and $12.6^{\circ}$, $18.0^{\circ}$ and $21.3^{\circ}$ of the Hwarang and $15.3^{\circ}$ and $22.7^{\circ}$ of the Seoak district. In the left, middle and right of soil hardness, the Sogeumgang was 29.9mm, 34.7mm and 31.1mm, 27.6mm, 35.0mm and 27.2mm of the Hwarang and 27.1mm, 30.8mm and 28.0mm of the Seoak district. The types of deterioration in trails were 10 types of the Sogeumgang, 11 types of the Hwarang and 9 types of the Seoak district. The trail erosion, rock exposure and root exposure were substantially observed in the types of deterioration. In the results of the naturalness assessment, the Hwarang district was a good condition, but the Sogeumgang district was bad. The indicators of the Sogeumgang district were mostly poor.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.27-39
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• 2011

The study on Musan twelve peaks of Yongho garden in Jinju, Gyeongnam was anticipated to provide data and implication for reproducing similar spaces and modern changes in terms of design factor since it is the prototype of traditional mount for overcoming monotonous geographical features and intriguing changes and interests. The study analyzed and interpreted the symbolism of twelve peaks, principles of space composition and function and effect of visual construction that were pursued by the builder in terms of landscape view, which results are as following. The center of Yongho garden, Yonghoji(龍虎池) is a typical man-made pond for a supportive feng shui feature. It is a supporting equipment to complete the state of feng shui, and the result of strengthening the completion through the connection with the dragon-related name of the place. The shape of Musan twelve peaks looks like an oval form of Geumseongsan(金星山), 2~3.5m in height and 6~12m in diameter. Peaks are estimated as 1.5~3.7m(2.4m in average) in height, $35{\sim}138m^2$($73.4m^2$ in average) in area, and $30.7{\sim}115.0m^3$($62.5m^3$ in average) in volume. Given that Yonghojeong(龍虎亭), Soseon(小船), the site of main building and Yongsanjae(龍山齋) stand in line, Yonghoji was presumed as the state of enlightenment through ascribing the meaning to virtue and secularity. For the intention of realizing Musan twelve peaks, the builder probably had mounted twelve peaks forming the body of dragons with crossing the point corresponding to a head of tiger, and located Musan twelve peaks and Yonghojeong with a representation of dragons holding Cintamani rising into the sky in the center. The middle area near Musan twelve peaks surrounded by peaks like Geumseongsan running north and south shows a multi-structure of multilayer, maintaining the similarity centering on Yonghoji. It is considered the intention of mount planned at the time of Musan twelve peaks construction, caused by similar form harmony. Internalization of progressive realization through concealment and exposure, enframement effect and spatial order like prospect-refuge theory in the mount of Musan twelve peaks is considered the reflection of the intention to increase depth of the view and expectancy through the various degree of exposure and surroundings of each peak and the colorful combination of viewing and shutting. The "closed view" by Musan twelve peaks creates interesting, vivid and attractive recognition of the view, which is more effective in bringing depth of the view and interests in terms of the geographical design, particularly the area around Yonghoji. Moreover, it was identified that the combination of peaks can be formed resulted from the view configuration concerning the location through multilayer effect reveals an island through the other one when viewed from Yonghojeong.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.35-36
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• 2006

This paper presents an effective multiplier in GF($2^m$) based on programmable cellular automata (PCA) and uses a normal basis. The proposed architecture has the advantage of high regularity and a reduced latency. The proposed architecture can be used in the effectual hardware design of exponentiation, division, inversion architectures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.619-624
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• 2002

In this paper, a novel architecture of programmable divider with fifty percent duty cycle output and programmable dividing number has been proposed. Through HSPICE simulation, a 900MHz frequency synthesizer with proposed (sequency divider has designed in a standard 0.25㎛ CMOS technology To verify the operation of proposed frequency divider, a chip had been fabricated using 0.65㎛ 2-poly, 3-metal standard CMOS processing and experimental result shows that the proposed frequency divider works well. The designed voltage controlled oscillator(VCO) has a center frequency of 900MHz a tuning range of $\pm$10%, and a gain of 154HHz/V. The simulated frequency synthesizer performance has a settling time of 1.5$\mu$s, a frequency range from 820MHz to IGHz and power consumption of 70mW at 2.5V power supply voltage.

• Architectural research
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• v.7 no.1
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• pp.11-18
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• 2005

In today's building industry the emphasis has been geared more towards construction, thus building maintenance and life cycle have been neglected until now. A direct result of this neglect is the rapid aging of building, which leads to more cost-effective decision making methods for the prolongation of building life span. The following study is conducted in the area of Daegu and Seoul in order to develop the estimation analysis method of the annual operation cost of the Korean high-rise condominiums for the cost-effective decision making support through mathematical and statistical analyses including the present value and standardized measurement corrections. Based on the assumption that the life expectancy of the high rise condominium is 50 years, initial cost is ￦421,212/$m^2$, and a total sum of yearly operation cost during life expectancy is ￦2,154,499//$m^2$), yearly accumulated operation cost is shown as below: $AOC=0.7097t^4-38.803t^3+806.95t^2+11045t-496.52$ ($R^2=0.98$) (Here, AOC = Accumulated Operation Cost, t = given years)

• Smart Structures and Systems
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• v.31 no.4
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• pp.335-349
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• 2023

Bridges constantly undergo deterioration and damage, the most common ones being concrete damage and exposed rebar. Periodic inspection of bridges to identify damages can aid in their quick remediation. Likewise, identifying components can provide context for damage assessment and help gauge a bridge's state of interaction with its surroundings. Current inspection techniques rely on manual site visits, which can be time-consuming and costly. More recently, robotic inspection assisted by autonomous data analytics based on Computer Vision (CV) and Artificial Intelligence (AI) has been viewed as a suitable alternative to manual inspection because of its efficiency and accuracy. To aid research in this avenue, this study performs a comparative assessment of different architectures, loss functions, and ensembling strategies for the autonomous segmentation of bridge components and damages. The experiments lead to several interesting discoveries. Nested Reg-UNet architecture is found to outperform five other state-of-the-art architectures in both damage and component segmentation tasks. The architecture is built by combining a Nested UNet style dense configuration with a pretrained RegNet encoder. In terms of the mean Intersection over Union (mIoU) metric, the Nested Reg-UNet architecture provides an improvement of 2.86% on the damage segmentation task and 1.66% on the component segmentation task compared to the state-of-the-art UNet architecture. Furthermore, it is demonstrated that incorporating the Lovasz-Softmax loss function to counter class imbalance can boost performance by 3.44% in the component segmentation task over the most employed alternative, weighted Cross Entropy (wCE). Finally, weighted softmax ensembling is found to be quite effective when used synchronously with the Nested Reg-UNet architecture by providing mIoU improvement of 0.74% in the component segmentation task and 1.14% in the damage segmentation task over a single-architecture baseline. Overall, the best mIoU of 92.50% for the component segmentation task and 84.19% for the damage segmentation task validate the feasibility of these techniques for autonomous bridge component and damage segmentation using RGB images.

• Current Research on Agriculture and Life Sciences
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• v.27
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• pp.69-75
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• 2009

This research regard it as most meaningful to realize the importance of the hedgerow in cultivated areas functioning as a residual landscape element in rural landscape and set improvement guidelines through landscape character and value analysis to cope with landscape malfunction. The results of summary are as follows. 1) First of all, as a result of landscape character analysis of edge stripe in cultivated land in total of 7 case areas, for example, the edge stripe in cultivated land in case area 4 and 8 maintain the width of 10m and are assessed satisfactory in terms of vegetation development condition, appearance of living species, connectivity, buffer capacity and so on. Also, as a result of structural character of correlation analysis among items, the correlation coefficient between width and appearance of living species showed 0.941, the highest. Following are connectivity and appearance of living species and width and buffer capacity respectively: 0.841 and 0.740. 2) As a result of landscape character analysis of uncultivated stripe in total of 6 case areas, it is analyzed that case area 4 maintains the widest width as almost 4.5m average width and considered valuable as I degree in vegetation development condition, filtering, and connectivity. 3) As a result of problem analysis of uncultivated stripe, for example, case 3, 9, and 10 was analyzed that the width was below 1.25m which is too small to carry out the function of buffer and habitat for living creature, so minimum standard width was set between 4~5m through comprehensive analysis of character of each case area. Based on the result above landscape character, value and problem analysis, main improvement guidelines are set in terms of width, connectivity, filtering, and vegetation development, restrictive practices and so on.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.10
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• pp.922-929
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• 2005

This paper compared ventilation performance between the sound roof tunnel with flat roof and the sound roof tunnel with gable roof. The ventilation rate of the sound roof tunnel is calculated by natural ventilation rate plus ventilation by vehicle. The roof type is divided by the shape of the roof and the ventilator location on the roof. The results between calculation and CFD on the ventilation rate are almost alike. The ventilation rate on the flat roof is $558.4\;m^3/s$ with mid-ventilator and $496.8\;m^3/s$ with left-right ventilator. The ventilation rate on the gable roof is $653.2\;m^3/s$ with mid-ventilator and $611.6\;m^3/s$ with left-right ventilator. The ventilation rate of soundproof with gable roof is higher than that with flat roof. The ventilation rate and with mid-ventilator is higher than that with left-right ventilator the soundproof roof. Therefore, the ventilation performance of soundproof roof depends on the roof shape and ventilator location on the roof.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.61-71
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• 2016

The purpose of the research is to identify the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria as leguminous woody plants for the cut-slope revegetation. To investigate the coverage ratio and appearance frequency, we divided Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria into five treatment groups with various quantities of $0.0g/m^2$, $1.0g/m^2$, $2.4g/m^2$, $3.8g/m^2$, and $5.2g/m^2$. For each treatment group, we mixed the identical quantities of herbaceous flowers (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena and Pennisetum alopecuroides) seeds and cool-season turfgrasses (Festuca arundinacea and Poa pratensis) seeds. In this result, as the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria increased in the spray, the coverage ratio for leguminous woody plants appeared to increase whereas the coverage ratio decreased in herbaceous flowers and cool-season turfgrasses. However, when the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria exceeded $3.8g/m^2$ in the spray, the coverage ratio of leguminous woody plants rather decreased compared to four treatment groups less than $3.8g/m^2$ seeding ratio. Based on the longitudinal data of coverage ratio in five treatment groups, we observed the gradual process of a short-term succession in which the dominant species shifted in the following order: First, cool-season turfgrasses; Second, herbaceous flowers; Third, leguminous woody plants. Comparing the appearance frequency of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria, Lespedeza cyrtobotrya appeared more frequent in 2014 whereas Indigofera pseudo-tinctoria appeared to be relatively more frequent in 2015. As a result, Indigofera pseudo-tinctoria was discovered to be a dominant species among woody plants. In this study, we observed that the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria was $2.4g/m^2{\sim}3.8g/m^2$. Moreover, the coverage ratio of 29.1%~35.4% and appearance frequency of 4.6plants~5.8plants were found in the condition of optimal seeding quantity.

• Journal of IKEEE
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• v.12 no.1
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• pp.34-42
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• 2008

This paper proposes a new on-chip voltage down converter(VDC), which employs a new reference voltage generator(RVG). The converter adopts a temperature-independence reference voltage generator, and a voltage-up converter. The architecture of the proposed VDC has a high-precision, and it was verified based on a 0.25${\mu}m$ 1P5M standard CMOS technology. For 2.5V to 1.0V conversion, the RVG circuit has a good characteristics such as temperature dependency of only 0.2mV/$^{\circ}C$, and the voltage-up circuit has a good voltage deviation within ${\pm}$0.12% for ${\pm}$5% variation of supply voltage VDD. The output voltage is stabilized with ${\pm}$1mV for load current varying from 0 to 100mA.