• Explosives and Blasting
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• v.20 no.2
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• pp.21-31
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• 2002

We did bench blasting upon the natural rock which it's uniaxial compressive strength was about $1,420~1,476kgf/\textrm{cm}^2$. This is the results we inferred after measuring, analyzing the ground vibration velocity of the front and back direction from the free face of the bench blasting. We have to induce the square and cube root scaled equation and the general equation to guarantee confidence upon the data when analyzing the measurement data of the test blasting. The variable distance is in reverse proportion to the permitted ground vibration velocity. The shorter is the exploding point to a protection structure, the bigger is the reflection that the direction of the free face experts the ground vibration velocity, The ground vibration velocity front of the free face tends become reduced about 38~46% compare with back of the free face in the range that the permitted ground vibration velocity is 2.0~5.0mm/sec. In case of 2.0mm/sec, when a protection structure is within about 95m, the max. allowable charge weight per delay on positing front of the free face can be more used about 2.61 times than that on positing back of the free face, in case of 3.0mm/sec within about 78m more about 2.38 times, in case of 5.0mm/sec within 60m more about 2.10 times. In case of 2.0~5.0mm/sec when a protection structure is within about 200m front from the free face, the max. allowable charge weight per delay can become about 1.52 times than the case on back to the free face.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.189-196
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• 2003

In this study, the vertical opening of the non-float midwater pair trawl net was maintained by controlling the length of upper warp. This was because the head rope was able to be kept linearly and the working depth was not nearly as changed with the variation of flow speed as former experiments in this series of studies have demonstrated. We confirmed that the opening efficiency of the non-float midwater pair trawl net was able to be developed according to the increase in front weight and wing-end weight. In this study, we described the opening efficiency of the non-float midwater pair trawl net according to the variation of front weight and wing-end weight obtained by model experiment in circulation water channel. We compared the opening efficiency of the proto type with that of the non-float type. The results obtained can be summarized as follows：1. The hydrodynamic resistance was almost increased linearly in proportion to the flow speed and was increased in accordance with the increase in front weight and wing-end weight. The increasing rate of hydrodynamic resistance was displayed as an increasing tendency in accordance with the increase in flow speed. 2. The net height of the non-float type was almost decreased linearly in accordance with the increase in flow speed. As the reduced rate of the net height of the non-float type was smaller than that of the net height of the proto type against increase of flow speed, the net height of the non-float type was bigger than that of the proto type over 4.0 knot. The net width of the non-float type was about 10 m bigger than that of the proto type and the change rate of net width varied by no more than 2 m according to the variation of the front weight and wing-end weight. 3. The mouth area of the non-float type was maximized at 1.75 ton of the front weight and 1.11 ton of the wing-end weight, and was smaller than that of the proto type at 2.0∼3.0 knot, but was bigger than that of the proto type at 4.0∼5.0 knot. 4. The filtering volume was maximized at 3.0 knot in the proto type and at 4.0 knot in the non-float type. The optimal front weight was 1.40 ton.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.104-112
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• 1992

The objectives of this study were: (a) to find the maximum ac- ceptable weight which can be carried for 8 hours using a psycho- physical method for front, side (one hand and two hands) and back carrying, and (b) to develop models which could predict the ac- ceptable maximum weight in carrying using isometric strength and anthropometric data. A series of laboratory experiments were conducted to find the maximum acceptable weight in front side and back carrying. Six college students participated in the experiment. It was found that subjects were willing to carry the heaviest load using two-hand side carrying (average maximum acceptable weight: 7.76 kg). Back carrying was the close second with 6.62 kg. Also, there was a significant difference (p< 0.01) in maximum acceptable weight for carrying between one-hand (4.40kg) and two-hand side carrying.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.2
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• pp.104-111
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• 2009

In this paper, optimization for frontal crashworthiness is carried out for the weight reduction design of an auto-body member with the advanced high strength steels(AHSS) such as 780TRIP and 780DP. The frontal crashworthiness is evaluated in order to optimize thicknesses for the front rail member of the ULSAB-AVC, Thicknesses of the front rail member with AHSS are optimized by comparison of crushing distance, absorbed energy and the deceleration for the auto-body with the response surface methodology. The results demonstrate that the crashworhiness of the front rail member with the optimum thicknesses of the AHSS is similar to analysis results obtained from the ULSAB-AVC project. The results also show that the weight reduction design is performed by substituting the AHSS for conventional structural steels such as 440E in the auto-body members.

• PNF and Movement
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• v.12 no.1
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• pp.13-17
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• 2014

Purpose: To determine the normative data for the correlation of spinal, pelvic parameters with foot pressure in the young subjects. Methods: The subjects of this study were 39 patients in healthy adults. The Formetric-III was used to measure of spinal alignment. The pedoscan was used to measure of foot pressure. The correlation of trunk imbalance, trunk inclination, lateral deviation with foot pressure. The foot pressure measurement was consisted of maximal/mean pressure, weight contribution. Result: There was a negative correlation of trunk inclination with Max_R. There was a negative correlation of trunk inclination with Max_R. There was a positive correlation of trunk imbalance with Max_L. There was a positive correlation of lumbar lordosis with Mean_R_front, Lt. posterior weight distribution. There was a negative correlation of lumbar lordosis with Lt., Rt. in distribution There was a negative correlation of pelvic tilt with Mean_R_front, Lt. posterior weight distribution. There was a positive correlation of pelvic tilting with Rt. weight distribution, Lt. posterior weight distribution. There was a negative correlation of pelvic torsion with Lt. weight distribution, Rt. posterior weight distribution. There was a negative correlation of pelvic rotation with Lt. weight distribution, Lt. posterior weight distribution. Conclusion: The data obtained from the study may be used for future studies related to correlation of the spinal, pelvic deviation with foot pressure.

• Korean Journal of Medicinal Crop Science
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• v.18 no.1
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• pp.51-55
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• 2010

This study was conducted to investigate the effect of planting position on the growth characteristics, yield and ginsenoside content in Panax ginseng C.A. Meyer at different growth stages. Referring to shoot growth characteristics, stem length, stem diameter and leave area were higher at front than rear, increasing as the proceeding of growth stages. But a lower chlorophyll contents was caused at front compared to rear and decreased as the proceeding of growth stages contrarily. According to root characteristics, root length and main body length were higher at front, with a positive correlation to growth stages, which was also shown on fresh root weight and dry root weight with the maximum in August. Meanwhile, the effect of planting position on ginsenoside content could also be definite by the highest content at front showing high light intensity, increasing as the proceeding of growth stages as well.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.1
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• pp.1-5
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• 1987

The authors carried out an experiment to determine the vertical opening of the midwater trawl, which is the same used in the former experiment in this series of studies. To determine the vertical opening of otter board and front weight, three fish finders were used. A 200 KHz fish finder set on board the research vessel was used to sound the depth of water. A transmitter of 50 KHz fish finder was set through the shoe plate of otter board to determine the height of otter board from the sea bed, and a transmitter of another 50 KHz fish finder was set downwardly on the net pendant right before the front weight to determine the height of weight from the sea bed. The depth of otter board and weight were calculated by subtract the height of those from the depth of water, respectively. To determine the vertical opening of mouth, a transmitter of net recorder was set on the head rope and the vertical opening of that to ground rope was directly read on the recording paper. The results obtained can be summarized as follows: 1. The rate of the depth of otter board to the length of warp was in the range of 0.44 to 0.25, and the depth was linearly shoaled about 5m per 0.1m/sec of the towing speed or per 20rpm of the main engine. The rate of the observed depth to the calculated depth of otter board was in the range of 0.92 to 0.080 with a decreasing tendancy in accordance with the increase of towing speed. 2. The depth of head rope was 2 to 3m deeper than that of otter board, and the vertical opening of net mouth was in the range of 22 to 19m, with a decreasing tendancy in accordance with the increase of towing speed, 3. The difference of depth between front weight and otter board was about 20m and 22m respectively in the length of warp 100m and 150m without distinct change in accordance with the towing speed. The depth of front weight was 2 to 3m shallower than that of ground rope. 4. The changing range of depth of head rope according to the revolution of main engine was about 4m per 20rpm.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.187-190
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• 2009

Recently, automotive companies have invested in vehicle weight reduction and clean car development because of oil price rises and environmental problems. In particular, USA car makers have developed the vehicle spending 1 liter per 34km complying with PNGV(Partnership for a new generation of vehicle) and Europe car makers have developed the vehicle spending 3 liters per 100km. The USA government announced "The green car policy" in order to boost production of more fuel effective cars in 2009. According to the policy, it will be restricted to sell the car which spends more than 1 liter per 14.9km by 2020. To satisfy the current situations on automotive market, hydroforming technology has widely adapted vehicle structures such as engine cradle, chassis frame, A pillar, radiator support, etc. However, automotive companies have to consider formability and performance to improve and maximize the benefit from this technology in advance of detail design. The paper deals with one of the vehicle weight reduction methods using tube hydroforming technology and platform commonality in front suspension. FEA simulation is also introduced to evaluate hydro-formability and NVH performance at the beginning of design stage which is the best way to reduce the failure cost.

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.71-80
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• 1998

This study proposed a method to apply certain fuzzy-related Quality control concepts to design customer-oriented products considering user requirements and information starting with the product development stage. This approach showed how to define the importance level of design elements and how to Quantify complex subjective perception of products using the fuzzy linguistic rating method and quality function deployment concepts. Using this approach, various customer requirements could be interpreted and reflected on the early design phase of a new product. To validate the proposed method, an experiment was conducted for designing the shape of the beeper using 14 subjects and 10 commercial beeper products. Front area, width/length ratio, thickness, curve variance, weight, and display area were selected as design elements of the beeper. The results showed that among design elements, front area and weight are significantly related with the subjective perception of the products. Consequently, this study indicates that customer decision on product selection could be made by quantification of user perception for beeper products.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.106-115
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• 2010

This study described the stability of riprap, which was examined by a two-dimensional physical model of a scattered riprap submarine breakwater. Artificial reef structures made of scattered riprap are used like artificial intertidal zone structures as waterfront seaside structures. To prevent topography change in such an artificial intertidal zone the energy is reduced at the scattered riprap submarine breakwater by intercepting high waves. The breaking waves are converted into flow on the front surface slope of the submarine breakwater, which follows the upper part of the artificial intertidal zone. Because of this phenomenon of resisting water flow, it is very important to calculate the required weight of the riprap to maintain its stability. The results of a physical model can be abstracted as shown below. First, distribute the wave breaking types occurring on the front surface slope of the submarine breakwater and arrange it in relation to the movement of riprap. Second, using the hydraulic phenomenon that occurs at the depth of the scattered riprap submarine breakwater, propose a calculation formula for the velocity distribution showing the influence on the stability of the riprap. Third, propose and compare values, which can be obtained by experiments and calculations for riprap stability on the front surface of the artificial intertidal zone. Fourth, calculate the required weight for riprap stability.