• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.101-110
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• 2006

In general, environment-induced vibration propagates from the center of source to the destination through ground. In fact, the mechanism of wave propagation is highly dependent on the ground conditions, and various methods to protect structures from such a ground vibration have been proposed. The method of wall barrier has been frequently used to cut off ground vibration effectively. However, the capability of wall barrier may be affected by various factors like constituent material of it. Therefore, it is important to figure out appropriate material for the wall barrier. This study is focused on the effect of EPS on the vibration protection. Centrifuge model tests were performed. Two types of models such as a cylindrical and a rectangular wall were used. For the cylindrical type of wall, installation depth was changed, while the length of the wall varied fur the rectangular type to figure out the capability of vibration protection.

• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.348-360
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• 2018

Purpose : The purpose of this study was to explore the meaning and essence of experience of family members as care givers of patient with head and neck cancer. Methods : This study was based on the colaizzi's phenomenological method, which describes the experiences about the family care givers. We had in-depth interview with family of five head and neck cancer patients. Results : Data was classified by 24 themes, 9 theme clusters and 4 categories. The categories are as follows: 'Shocking and actuality like a deadly maze', 'Cut off from the world by changes in family's physical image', 'Exhaustion of family', 'Take-off for mature care'. Conclusion : The results of the study provide useful information in understanding care givers' experience of patient with head and neck cancer and establishing effective strategies to support these care givers.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.4
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• pp.397-402
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• 2013

In this study, we carried out the each lines of section, using GC (green silicon carbide) whetstone, the SCM415 material which separated by after and before heat treatments process, in 3+2 axis machining centers for integrated grinding after cutting end mill works, the spindle speed 8000 rpm and feed rate 150 mm/min. For the analysis of the centerline average roughness (Ra), we measured by 10 steps stages. Using Finite element analysis, we found the result of the load analysis effect of the assembly parts, when applied the 11 kg's load on both side of the ATC (Automatic tool change) arm. The result is as follows. For the centerline average roughness (Ra) in the non-heat treatment work pieces, are appeared the most favorable in the tenth section are $0.510{\mu}m$, that were shown in the near the straight line section which is the smallest deformation of curve. In addition, the bad surface roughness appears on the path is to long by changing angle, the more inclined depth of cut, because the chip discharging is not smoothly.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.387-393
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• 2012

It is very difficult to determine suitable cutting conditions in order to obtain accurate cutting profiles because machining errors caused by tool deflection depend upon cutting conditions. In this study the relationship between real cutting profiles (inclined shapes and machining errors) and cutting conditions was modeled in order to fabricate draft angle on micro molds. CCD (Central Composite Design) of DOE (Design Of Experiment) and RSM (Response Surface Method) were applied in order to model the relationship between cutting conditions and machining errors. In order to use CCD the range of radial depth of cut was chosen by $10-90{\mu}m$ and the range of feedrate was chosen by 200-300mm/min, and 9 points of cutting conditions were chosen inside determined ranges. Then, actual cutting processes were carried out as respect to 9 points of cutting conditions, draft angles and real cutting profiles were measured on cutting profiles, each response surface function was determined by conducting response surface analysis and the functions were represented by 3-dimensional graphs, contour lines and $101{\times}101$ matrices. Consequently it is possible to determine suitable cutting conditions in order to obtain arbitrary given draft angles and cutting profiles by using modeling. To validate proposed approach in this study suitable cutting conditions were determined by modeling in order to obtain arbitrary given draft angle and cutting profile, and actual cutting processes were carried out. About 95% of good agreement between predicted and measured values was obtained.

• Explosives and Blasting
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• v.34 no.4
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• pp.1-9
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• 2016

For underwater steel structure, cut that underwater shaped charge device that combines a spring hose, which is an external device of pressure resistance and flexibility with flexible shaped charge, was invented. As a basic experiment for an optimum condition design, an penetration performance was compared by external device shape. To evaluate the result of an experiment, image analysis was carried out after obtaining the model by using the liquid rubber for the penetrated steel plate. To simulate the penetrating process of shaped charge, the AUTODYN program has been used. As a result of analysis, while the average penetration depth of circular and square shaped external devices were similar, the penetration quality was more uniform in the case of circle. In addition, water infiltration occurred in square case, displacement and strain rate according to the increase of the water pressure were measured high.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.156-161
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• 2002

It depends on the joint configuration, dimensions and constraints on the joint whether the residual stress at the root of single-sided butt weld is tensile or not. Therefore, recommendation is generally made that high R ratio should be used in the fatigue test of this type of joint in order to prevent excessively long life caused by compressive residual stress. in this research, the residual stress profile in butt weld joint was obtained through compliance method, using successive extension of a slot and measurement of the variation of strain during the slot extension. The residual stress profile was firstly assumed to be the linear summation of Legendre polynomials up to 9th order excluding 0th and 1st order. Strain variation on the surface was measured while the slot was being extended by cutting to find out the 8 unknown coefficients of each polynomial tenn. The cut was made by the electric discharge machine. It was concluded that the residual stress near the surface stayed positive, however, it turned into the negative value as soon as it passed through 2 or 3 mm depth. Several fatigue tests were also carried out under zero stress ratio. Test results showed that fatigue life coincides well with the design cuive of butt joint in British Standards, which supports that it is tensile residual stress that exists near the weld root.

• Food Science and Preservation
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• v.24 no.3
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• pp.381-386
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• 2017

Ergocalciferol is known as having vitamin D activity. In this study, the effects of UV irradiation on the increase of egocalciferol content were investigated in 7 kinds of mushrooms, i.e, lily mushroom (Flammulina velutipes), oyster mushroom (Pleurotus ostreatus), young oyster mushroom (Pleurotus ostreatus), king oyster mushroom (Pleurotus eryngii), button mushroom (Agaricus bisporus), shiitake (Lentinula edodes), and wood ear mushroom (Auricularia auricula-judae). Mushrooms which were not exposed to UV light contained negligible amount of ergocalciferol in all kinds of tested mushrooms, but UV irradiation increased their content of ergocalciferol. Of UV A, B and C, UV B light was the most effective to increase ergocalciferol contents. In mushrooms, the increase in ergocalciferol content occurred only in the peel within 1 mm depth from the surface, which was directly exposed to the UV light. Therefore, when fresh whole mushrooms were irradiated with UV light, lily mushroom, the mushroom with a larger surface area compared to volume, such as lily mushroom, was more favorable in producing ergocalciferol. On the other hand when the mushrooms were freeze-dried and cut, the mushrooms with a higher ergosterol, such as king oyster mushroom, shiitake or button mushroom, were more favorable in generating ergocalciferol.

• Tunnel and Underground Space
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• v.32 no.4
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• pp.243-253
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• 2022

In this study, the cutting efficiency of TBE (Tunnel Boring Extender) was evaluated by using rotary cutting tester. In the rotary cutting test, a specimen which has a drilled hollow hole at the center was made of rock-like material. The specimen was cut by UDC (undercutting disc cutter) with spiral cutting path to simulate the cutting process of TBE. The cutting forces and specific energy were evaluated under different cutting conditions. The results indicated that the cutter forces of UDC linearly increased with the vertical and radial penetration depths. Among the three directional cutter forces, the normal force is larger than other force components. While the specific energy decreased with the two penetration depths, in particular, it was presumed that the specific energy was minimized at a certain value of the ratio of radial to vertical penetration depth.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.497-502
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• 2018

The purpose of this study is to investigate the correlation between female gradation angle and angles of female gradation according to the angle of the treatment. A total of 100 questionnaires were analyzed using questionnaires. The results showed that sophisticated images were observed at $5^{\circ}$, $31^{\circ}$, and $85^{\circ}$ of gradation, and elegance images were observed at $15^{\circ}$ and $65^{\circ}$, and modern images were observed at $50^{\circ}$. Through this study, we will be able to conduct in-depth follow-up research on female gradation cuts classified by the trend position of trends in Korean men, and it will be possible to use it as basic data for deeper haircut education at the same time as creating customer satisfaction.

• Journal of the Korean Geosynthetics Society
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• v.15 no.4
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• pp.9-16
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• 2016

During the 2004 Niigata-ken Chuetsu, Japan, earthquake, more than 1,450 underground structures, known as sewer manhole, were uplifted up to 1.5m in Nagaoka and Ojiya city. The uplift damage can be a serious matter because they not only hinder the flow of wastewater systems, as a part of lifeline systems, but also disturb traffic flows. For restoration works, an open-cut investigation of damaged wastewater system was conducted by the Nagaoka city government. The results from the investigation compiled valuable data sets for buried pipeline damage due to earthquakes. In the present study, the factors affecting the uplift amount of the underground structure is investigated by using the data sets which include locations of damaged sections and inclination of pipeline before and after the earthquake and the SPT borehole logs in the affected area. Correlation analysis between the underground structure uplift and the geological settings in the affected area revealed that ground water depth and original subsoil, including thickness of clay layer, SPT N-value and fill thickness are the key parameters for the uplift phenomenon.