• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.40 no.4
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• pp.49-57
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• 2022

This study was conducted with the aim of investigating the garden architectural characteristics of Villa d'Este, which occupies a major role in the exploration of the contrasting background, location, and spatial composition characteristics of Italian Renaissance gardens. The survey for the study was divided into a literature survey and a field survey, and the details are as follows. First, in the mid-to-late 16th century, the villa was built under the direction of Cardinal Ippolito d'Este, and afterwards, the ownership of the villa was restored to the Italian government in 1850 due to financial difficulties. The Villa d'Este, which suffered another damage, is now operated with many visitors after going through the restoration process. Second, in the case of location, it has the characteristics of Urbana located in the city center and has valley-type topographical conditions located at the foot of the mountain.Third, in the case of spatial composition, it is orthogonal to the axis, and each part of the garden is developed, influenced by the contrast principles such as the installation of the Cortile del Belvedere and Villa Madama in the early 16th century. The main building is located in the hills so that you can see the garden and the surrounding scenery at a glance. Fourth, among the components, there were stairs, logia, courtyard, and grotto, fountains, cascades, ponds, and vegetation such as laurels, thorn trees.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.107-111
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• 2017

The reliability on high cycle fatigue damage mechanism for new blades manufactured by reverse-engineering is demonstrated by success-run test. Turbine blades always experience various dynamic loads in turbine operation, as well as being in resonance condition and forced by fluid-induced vibrations mostly during run-up/down, which may accumulate high cycle damage to the blades. The accidents caused by blade failure especially incur not only a lot of troubles to the machinery but also huge financial losses. Therefore it is necessary to verify the reliability of blades in advance for the safe use. The success run test for the reliability demonstration is designed and performed for the new blades using the technique known as resonant high cycle fatigue testing.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.388-397
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• 2001

In forestry, where improvement of labor environment is quite impossible, improved posture would result in direct effects by preventing waste of physical strength, prevention of accidental injury caused by fatigue accumulated on certain body parts, and prevention of human error by inattentiveness due to weakened body. Therefore, this research carried on analysis of working posture in manual forest work(thinning using chain-saw, salvage cutting using chain-saw, clearing using hand saw, clearance of twiner using sickle, pruning using saw with a long handle, and tending of young growth using sickle) using OWAS analysis system. According to the OWAS method, percentage of OWAS action categories III and IV in the tasks using chain-saw and sickle was higher than another tasks. For the compared middle skillful worker group and low skillful worker group at felling work using chain-saw, percentage of OWAS action categories IV in middle skillful worker group was 5.1%, and low skillful worker group was 14.1%.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.6
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• pp.496-503
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• 2016

Leakages at plant structures of power and petrochemistry plants have led to casualties and economic losses. These leakages are caused by fatigue failure of pipelines and their wall thickness. Vibration measurement methods for plant pipelines mainly use acceleration and laser sensors. These sensors are difficult to install and operate and thus lead to an increase in operational cost especially for wide area surveillance. Recently, measurements of leak and vibration displacements using cameras have attracted the interest of many researchers. This method has advantages such as simple installation, long distance monitoring, and wide area surveillance. Therefore, in this paper, we have developed a system that can measure the leakage and vibrational displacement by using a camera. Furthermore, the developed system was verified with experimental data.

• Journal of the Society of Disaster Information
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• v.19 no.2
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• pp.262-269
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• 2023

Purpose: In this study,fire-resistance test were executed to evaluate the effectiveness of the fireproof panel attached to the PSC slab in tunnel. Method: For the fire resistance test, the RWS curve was applied and the furnace of the KICT was used. Result: As a result of the experiment, the maximum temperature measured on the concrete surface of the PSC slab with the fireproof panel was 321.8℃, which was lower than the damage limit temperature of 380℃ for concrete. Also, at the t=25mm, the maximum temperature was 35.2℃, which was lower than the damage temperature of steel, 250℃. The use of precast fire resistance panel(t=30mm) improves fire resistance of PSC structures. Conclusion: As a result of the test, a reinforcement method for attached a fireproof panel in case of fire in a tunnel or an underground roadway is provided to protect a structure from fire. In the future, it is necessary to perform the static performance test of the slab to which the fireproof panel is attached, and to confirm the adhesion performance of the fireproof panel by performing the pull-off test and the fatigue test.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.11
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• pp.437-444
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• 2017

Electric Pole is a supporting beam used for power transmission/distribution which is sensitive to external force change of environmental factors. Therefore, power facilities have many difficulties in terms of maintenance/conservation from external environmental changes and natural disasters that cause a great economic impact. The aerial wire cause elasticity due to the influence of temperature, or factors such as wind speed and wind direction, that weakens the electric pole. The situation may lead to many safety risk in day-to-day life. But, the safety assessment of the pole is carried out at the design stage, and aftermath is not considered. For the safety and maintenance purposes, it is very important to analyze the influence of weather factors on external forces periodically. In this paper, we analyze the acceleration data of the sensor nodes installed in electric pole for maintenance/safety purpose and use Kalman filter as noise compensation method. Fast Fourier Transform (FFT) is performed to analyze the influence of each meteorological factor, along with the meteorological factors on frequency components. The result of the analysis shows that the temperature, humidity, solar radiation, hour of daylight, air pressure, wind direction and wind speed were influential factors. In this paper, the influences of meteorological factors on frequency components are different, and it is thought that it can be an important factor in achieving the purpose of safety and maintenance.

• Journal of Energy Engineering
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• v.27 no.2
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• pp.1-13
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• 2018

The proportion of natural gas-fueled power generation is expanding due to the change of domestic energy policy pursuing reduction of dust and increasing clean energy consumption. Natural gas fuels used for the combined-cycle power plants and the district-heating power plants are operated at high temperature and high pressure in the fuel supply system. Accidents due to leakage of the gas such as fire and explosion should be prevented by applying risk management techniques. In this study, risk assessment was performed on the natural gas fuel supply system of a combined power plant based on the API RP 581 RBI code. For the application of the API RBI code, lines and segments of the evaluation target system were identified. Operational data and input information were analyzed for the calculations of probability of failure and consequence of failure. The results of the risk assessment were analyzed over time from the initial installation time. In the code-based evaluation, the gas fuel supply system was mainly affected by thinning, external damage, and mechanical fatigue damage mechanisms. As the operating time passes, the risk is expected to increase due to the external damage caused by the CUI(Corrosion Under Insulation).

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.82-82
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• 2009

Although leakage at a low carbon steel pipe made by electrical resistance welding(ERW) was reported due to grooving corrosion, the cause for the corrosion has not yet been cleared. So lots of researches were carried out already about grooving corrosion mechanism of ERW carbon steel pipe but there is seldom study for water hammer happened by fluid phenomenon and corrosion rate by flow velocity. In this study, the corrosion test carried out using the ERW carbon steel pipe by changed the water speed and heat input in a month. The level of dissolved oxygen is maintained 5~5.5mg/l(amount of dissolved oxygen in tap water). The water speed for corrosion test is 1m/s, 2m/s, 3m/s. As the results, grooving corrosion rate is increased cause by water speed in the pipe. In the case of the ERW pipe with more heat input, grooving corrosion rate is decreased. It is therefore that welding heat input should be controlled based on the carbon content of the pipe in order to improve the corrosion reistance of the ERW pipe.

• Composites Research
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• v.33 no.4
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• pp.177-184
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• 2020

Flame retardant(FR) clothes prohibit additional fire diffusion and make the personnel do their tasks without a hitch in a flammable environment. The existing FR clothes, however, are heavy and give high thermal fatigue. Therefore, it is strongly demanded to develop a light, convenient, and eco-friendly clothes. Recently, many works have been reported to make FR fabrics with phosphorus compounds, but their performance could not satisfy the specified criteria in appraisal standards of domestic and American FR clothes or combat uniforms. In this paper, two kinds of phosphorus compounds were applied to cotton fabric. Graphene oxide functionalized with a phosphorus-rich deep eutectic solvent and ammonium polyphosphate were coated on cotton fabric by eco-friendly padding procedure. The coated fabrics were analyzed with thermogravimetric analysis, vertical flame resistance test(ASTM D6413), cone calorimeter test(ISO 5660-1), and method of test for limited flame spread(ISO 15025). It was revealed that the as-made cotton with those two materials simultaneously had better flame resistance than the cottons with each one. Furthermore, an additional coating for hydrophobicity on the FR cotton was tried for better washing fastness.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.1-11
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• 2019

The accident of mass transit such as a bus could draw the large casualties and this induces social and economic losses. Recently, severe bus accidents caused by tiredness and inattention of bus drivers occurred and those lead to growing interest in bus accidents and the drivers' work environment. Therefore, this study analyzes the accident based on the work environment of bus drivers and route-bus categories. For the research, this study collected digital tachograph data and the bus company information for 271 domestic bus companies in 2017 and used ANOVA test and chi-square test as statistical methodologies. As a result, we figured out there are statistically significant differences in the accident according to the working environments. Especially, the present study confirmed the intracity bus with working every other day has the most frequent accidents. We expect that the results of this study be used as foundations for the improvement of working conditions to reduce route-bus accidents in the future.