• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.1-14
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• 2014

It is necessary to decide the pumping rate and pumping well location together with the capture zone in order to determine an appropriate groundwater remediation strategy to manage the contaminated groundwater. The relationship between the capture zone and the drawdown radius of influence ($ROI_s$) was considered. $ROI_{cs}$ is defined as the distance where the criteria of drawdown is cs meter from pumping well in this paper. A method to decide the required pumping rate for the remediation of contaminated groundwater in order to create appropriate $ROI_{cs}$ is suggested by using the Theis equation (1935) and Cooper-Jacob equation (1946). It was shown in this study that $ROI_{cs}$ is in proportion to the pumping rate and the criteria of drawdown, which decides $ROI_{cs}$, is inversely proportional to Ti value (transmissivity ${\times}$ hydraulic gradient). The pumping rate which creates the required $ROI_{cs}$ could be planned through the relationship between the $ROI_{cs}$ and pumping rates ($ROI_{cs}$-Q curve) of the field sites 1, 2 and 3. If the drawdown is investigated along with Ti value and pumping rate at a specific site where pump and treat remediation is planned, it is expected that the required criteria of drawdown can be evaluated by using the relationship between the cs and Ti (cs-Ti curve).

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권5호
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• pp.473-483
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• 2017

Comprehensive consideration regarding influence mechanisms of initial imperfections on ultimate strength of spherical shells is taken to satisfy requirement of deep-sea structural design. The feasibility of innovative numerical procedure that combines welding simulation and non-linear buckling analysis is verified by a good agreement to experimental and theoretical results. Spherical shells with a series of wall thicknesses to radius ratios are studied. Residual stress and deformations from welding process are investigated separately. Variant influence mechanisms are discovered. Residual stress is demonstrated to be influential to stress field and buckling behavior but not to the ultimate strength. Deformations are proved to have a significant impact on ultimate strength. When central angles are less than critical value, concave magnitudes reduce ultimate strengths linearly. However, deformations with central angles above critical value are of much greater harm. Less imperfection susceptibility is found in spherical shells with larger wall thicknesses to radius ratios.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.1-6
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• 2015

The objectives of this study were to calculate the radius of influence (ROI) of well for an air-sparging (AS)/soil vapor extraction (SVE) system and to evaluate the applicability of the system applied for the remediation of the petroleum contaminated rail site. For air permeability test, three monitoring wells were installed at a location of 1.3 m, 2.3 m, 3.0 m from the extraction well. And the pressure of each monitoring well was measured by extracting air from the extraction well with the pressure and flow of $(-)2,600mmH_2O$ and $1.58m^3/min$. The ROI for an extraction well was calculated as 4.31 m. Air was injected into the injection well with the pressure and flow of $3,500mmH_2O$ and $0.6m^3/min$ to estimate the radius of influence for oxygen transfer. Oxygen concentrations of air from three monitoring wells were measured. The ROI of an injection well for oxygen transfer was calculated as 3.46 m. The 28 extraction wells and 19 injection wells were installed according to the ROI calculated. The AS/SVE system was operated eight hours a day for five months. The rail site was contaminated with the petroleum and concentrations of benzene, toluene, and xylene were over the 'Worrisome Standard' of the 'Soil Environment Conservation Act'. The contaminated area was estimated as $732m^2$ and contaminants were dispersed up to (-)3 m from the ground. During the operation period, soil samples were collected from 5 points and analyzed periodically. With the AS/SVE system operation, concentrations of benzene, toluene, and xylene were decreased from 7.5 mg/kg to 2.0 mg/kg, from 32.0 mg/kg to 23.0 mg/kg, from 35.5 mg/kg to 23.0 mg/kg, respectively. The combined AS/SVE system applied to the rail site contaminated with volatile organic compounds (VOCs) exhibited a high applicability. But the concentration of contaminants in soil were fluctuated due to the heterogeneous of soil condition. Also the effect of the remediation mechanisms was not clearly identified.

• 지질공학
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• 제20권2호
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• pp.127-136
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• 2010

본 연구에서는 현장에서 수행한 단계양수시험을 이용하여 최적 양수량, 우물효율 및 양수 영향반경을 산정하였다. 시험결과 최적 양수량은 KDPW 1, KDPW 2에서 수위강하가 0.5, 1.0 m 일어났을 때 각각 9.37, 16.20 $m^3/day$과 8.11, 14.10 $m^3/day$으로 계산되었다. 또 우물효율은 KDPW 1에 대하여 72.02~90.73%의 효율을 그리고 KDPW 2에 대하여 70.62~88.52%의 효율을 보였다. 한편 정류상태 해석으로 영향반경은 KDPW 1에서 양수하였을 경우 관측정에서 3.50~31.92 m로 계산되었다. 또 KDPW 2에서 양수하였을 경우 관측정에서 영향반경이 0.14~37.43 m로 산정되었다. 부정류 해석결과에 따르면 KDPW 1에서 양수하였을 경우 관측정에서 영향반경이 0.02~8.34 m로 계산되었다. 그리고 KDPW 2에서 양수하였을 경우 관측정에서 영향반경이 0.24~9.68 m로 계산되었다. 본 연구에서 적용한 방법론은 오염지하수 양수처리법의 설계에 실용적으로 활용될 수 있을 것으로 사료된다.

• Animal cells and systems
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• 제16권2호
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• pp.121-126
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• 2012

In this study, a neural network (NN) modeling approach has been used to predict the mechanical and geometrical behaviors of mouse embryo cells. Two NN models have been implemented. In the first NN model dimple depth (w), dimple radius (a) and radius of the semi-circular curved surface of the cell (R) were used as inputs of the model while indentation force (f) was considered as output. In the second NN model, indentation force (f), dimple radius (a) and radius of the semi-circular curved surface of the cell (R) were considered as inputs of the model and dimple depth was predicted as the output of the model. In addition, sensitivity analysis has been carried out to investigate the influence of the significance of input parameters on the mechanical behavior of mouse embryos. Experimental data deduced by Fl$\ddot{u}$ckiger (2004) were collected to obtain training and test data for the NN. The results of these investigations show that the correlation values of the test and training data sets are between 0.9988 and 1.0000, and are in good agreement with the experimental observations.

• Wind and Structures
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• 제26권3호
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• pp.179-190
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• 2018

Translation of tornadoes is an important feature in replicating the near-ground tornado flow field which has been simulated in previous studies based on Ward-type tornado simulators using relative motion of the ground plane. In this laboratory investigation, effects of translation on the near-ground tornado flow field were studied using the ISU Tornado Simulator that can physically translate over a ground plane. Two translation speeds, 0.15 m/s and 0.50 m/s, that scale up to those corresponding to slowly-moving tornadoes in the field were selected for this study. Compared with the flow field of a stationary tornado, the simulated tornado with translation had an influence on the spatial distribution and magnitude of the horizontal velocities, early reversal of the radial inflow, and expansion of the core radius. Maximum horizontal velocities were observed to occur behind the center of the translating tornado and on the right side of its mean path. An increase in translation speed, resulted in reduction of maximum horizontal velocities at all heights. Comparison of the results with previous studies that used relative motion of the ground plane for simulating translating tornadoes, showed that translation has similar effects on the flow field at smaller radial distances (~2 core radius), but different effects at larger radial distances (~4 core radius). Further, it showed that the effect of translation on velocity profiles is noticeable at and above an elevation of ~0.6 core radius, unlike those in studies based on the relative motion of the ground plane.

• Geomechanics and Engineering
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• 제21권3호
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• pp.289-300
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• 2020

Estimating the damage induced by an explosion around a blast hole has always been a challenging issue in geotechnical engineering. It is difficult to determine an exact dimension for damage zone since many parameters are involved in the formation of failures, and there are some uncertainties lying in these parameters. Thus, the present study adopted a probabilistic approach towards this problem. First, a reliability model of the problem was established and the failure probability of induced damage was calculated. Then, the corresponding exceedance risk curve was developed indicating the relation between the failure probability and the cracked zone radius. The obtained risk curve indicated that the failure probability drops dramatically by increasing the cracked zone radius so that the probability of exceedance for any crack length greater than 4.5 m is less than 5%. Moreover, the effect of each parameter involved in the probability of failure, including blast hole radius, explosive density, detonation velocity, and tensile strength of the rock, was evaluated by using a sensitivity analysis. Finally, the impact of the decoupling ratio on the reduction of failures was investigated and the location of its maximum influence was demonstrated around the blast point.

• 한국산업융합학회 논문집
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• 제5권3호
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• pp.201-208
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• 2002

The machine tool which operates by hand is replacing by CNC machine tool to improve the quality of the product and the productivity in modem mechanic industry. The precision of machine part is influenced greatly the surface roughness by cutting condition of machine tool. So this study was performed to examine the aluminium surface roughness of section according to change of strength rating, nose radius, cutting speed, using live center. The results of this study are as follows; 1. In the case of 56mm diameter of test piece(length is below triple of diameter), whether establish the live center or not, doesn't influence to the surface roughness, and it is possible to make product without the live center. 2. The average surface roughness of 42mm diameter(length is quadruple of diameter) is similar to the 56mm diameter in the cutting condition of nose radius 0.8mm and cutting speed 140mm/min, but there are increases and differences in other cutting conditions. 3. In the case of test piece length more 70m/min(140m/mm) and nose radius improved greatly using the live center. 4. In the case of test piece length is quintuple of diameter, the nose radius must choose big tool and increase the cutting speed in preference live center establishment availability to improve that is surface roughness. Conclusively, if aluminum test piece length is fewer than triple of diameter, can process without establishing live center. If aluminum test piece length is more than quintuple of diameter, cutting conditions to improve surface roughness are (1) cutting speed (2) nose radius (3) whether the live center uses or not.

• Geomechanics and Engineering
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• 제30권6호
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• pp.539-549
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• 2022

Accidental anchor drop can cause disturbances to seabed materials and pose significant threats to the safety and serviceability of submarine structures such as pipelines. In this study, a series of anchor drop tests was carried out to investigate the penetration mechanism of a Hall anchor in sand and clay. A special anchor drop apparatus was designed to model the inflight drop of a Hall anchor. Results indicate that Coriolis acceleration was the primary cause of large horizontal offsets in sand, and earth gravity had negligible impact on the lateral movement of dropped anchors. The indued final horizontal offset was shown to increase with the elevated drop height of an anchor, and the existence of water can slow down the landing velocity of an anchor. It is also observed that water conditions had a significant effect on the influence zone caused by anchors. The vertical influence depth was over 5 m, and the influence radius was more than 3 m if the anchor had a drop height of 25 m in dry sand. In comparison, the vertical influence depth and radius reduced to less than 3 m and 2 m, respectively, when the anchor was released from 10 m height and fell into the seabed with a water depth of 15 m. It is also found that the dynamically penetrating anchors could significantly influence the earth pressure in clay. There is a non-linear increase in the measured penetration depth with kinematic energy, and the resulted maximum earth pressure increased dramatically with an increase in kinematic energy. Results from centrifuge model tests in this study provide useful insights into the penetration mechanism of a dropped anchor, which provides valuable data for design and planning of future submarine structures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.145-149
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• 1997

STEP AP224 includes the information of machining feature and tolerances. Machining features are machined from raw material. Tolerance constrain feasible methods of manufacture, strongly influence the cost of manufacture. And tolerances influence the machining process. We need to decide the precedence between features .tool radius and tool direction for minimum tool changes. This paper deals with the method of decision of precedence between features and process parameters using feature information and tolerances in STEP AP224.