• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.614-621
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• 2004

Blasting is a technique for rock excavation: For instance, a rock cutting in a mountain side to prepare a base for a road. The blasting damage affect the rock slope stability. Therefore control blasting must be used. In this study, cutting cases of Sixty-nine rock blasts were investigated. Blasting damage patterns in rock slope and reinforcement methods are studied.

• Journal of the Korean Society for Precision Engineering
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• v.1 no.1
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• pp.34-49
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• 1984

The stability of machine tool systems is analyzed by considering the machining process as a stochastic process without decomposing into machine tool structural dynamics and cutting processes. In doing so the time series analysis technique developed by Wu and Pandit is applied systematically to the relative vibration between cutting tool and work- piece measured under actual working conditions. Various characteristic properties derived from the fitted ARMA(Autoregressive Moving Average) Models and those from raw data directly are investigated in relation with the system stability. Both damping ratio and absolute value of the characteristic roots of the AR part of the most significant dynamic mode are preferred as stability indicating factors to the other pro-perties such as theoretical variance .gamma. (o) or absolute power of the most dominant dynamic mode. Maximum aplitude during a certain interval and variance estimated from raw data are shown to be very sensi- tive to the type of the signal and the location of measurement point although they can be obtained rather easily. The relative vibration signal is also analyzed by FFT(Fast Fourier Transform) Analyzer for the purpose of comparison with the spectrums derived from the fitted ARMA models.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.183-190
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• 2001

There are complicated and big shear zone which is about several tens meter in the middle of the cutting slope in this study area. And slope stability analysis is very hard because many fault zones are gathered in the shear zone. This study furnish imformations of scrutinized geological survey, numerical stability analysis, reinforcement work analysis and computation of ground mass properties. Then this offer rational slope stability analysis, rock mass decision and counterplan.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.117-125
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• 2018

The primary objectives of this study are to develop a detail design of automated PHC pile head cutting machine and structural stability analysis of detail design that improves the conventional head cutting work in safety, quality, and productivity. For this, the following research works are conducted sequentially; 1)literature review and field study, 2)expert survey and interview, 3)selection of core technology using AHP analysis, 4)deduction of detail design 5) verification of structural stability. As an outcome, it is analyzed that gripper and gripper bearing shaft are structurally stable. Their maximum stresses are shown as 15.93%, 10.58% compared to their yield strength respectively. The results of detail design and structural stability analysis in this study will be utilized for the actual development of the automated PHC pile cutting machine prototype.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.123-129
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• 2000

To make high accuracy cutting of long materials and a piston for the engines it must be necessary to keep the thermal stability of spindle and tail stock in CNC lathe. If a object is clamped at the ends the thermal expansion and cutting process generate the deflection of cutting objects. Especially in the case of a piston ring piston ovality and piston profile the influences of deflection are very serious. In order to solve the problems most of piston cutting are worked under simply support. However the prob-lems exist yet. Therefore this paper proposes the new structure of tail stock which can compensates the deflection.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.361-366
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• 2000

To make high precision cutting of long materials or a piston for the engines, it must be necessary to keep the stability of spindle and tail stock in CNC lathe. If a object is clamped at the ends, the thermal expansion and cutting generated in cutting process appear as the deflection of in cuttings objects. Especially, of a piston ring, piston ovality and piston profile, the influences are very serious. In order to solve the problems most of piston cutting are worked in simply support. However, the problems exist, yet.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.1
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• pp.69-77
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• 1993

Adaptive Control is applied to regulate cutting force in turning operation under varying cutting conditions. Regulation is achieved primarily by adjusting feedrate. Such control leads to better machine utilization and increased tool life. The modeling of adaptive control system in turning operation is presented. The experimental results show that the adaptive PI controller is stable and performs more effective force control over wide range of cutting conditions as compared with the fixed gain PI controller.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.67-78
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• 2018

The stability of cutting slope influences the safety of railway operation, and how to identify the stability of the slope quickly and determine the rational monitoring plan is a pressing problem at present. In this study, the attribute recognition model of risk assessment for high cutting slope stability in the heavy haul railway is established based on attribute mathematics theory, followed by the consequent monitoring scheme design. Firstly, based on comprehensive analysis on the risk factors of heavy haul railway loess slope, collapsibility, tectonic feature, slope shape, rainfall, vegetation conditions, train speed are selected as the indexes of the risk assessment, and the grading criteria of each index is established. Meanwhile, the weights of the assessment indexes are determined by AHP judgment matrix. Secondly, The attribute measurement functions are given to compute attribute measurement of single index and synthetic attribute, and the attribute recognition model was used to assess the risk of a typical heavy haul railway loess slope, Finally, according to the risk assessment results, the monitoring content and method of this loess slope were determined to avoid geological disasters and ensure the security of the railway infrastructure. This attribute identification- risk assessment- monitoring design mode could provide an effective way for the risk assessment and control of heavy haul railway in the loess plateau.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1265-1272
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• 2016

The present study evaluated the effects of different cutting height on nutritive value, fermentation quality, in vitro and in vivo digestibility of whole crop barley silage. Whole crop barley forage (Yuyeon hybrid) was harvested at height of 5, 10, and 15 cm from the ground level. Each cutting height was rolled to make round bale and ensiled for 100 days. After 100 days of ensiling, pH of silage was lower (p<0.05) in 5 cm, but no difference between 10 and 15 cm of cutting height. The content of lactate and lactate to acetate ratio were increased (p<0.05) in 5 cm of cutting height, whereas the acetate content was higher (p<0.05) in 10 and 15 cm than that of 5 cm cutting height. Aerobic stability was greater (p<0.05) in silages of 10 and 15 cm of cutting height. Three total mixed rations (TMR) were formulated with silages from the three different cutting heights (TMR5, TMR10, and TMR15) incorporated as forage at 70:30 ratio with concentrate (dry matter [DM] basis). In vitro dry matter digestibility was higher (p<0.05) in the TMR5 and TMR10 than that in TMR15, whereas in vitro neutral detergent fiber digestibility was higher (p<0.05) in the TMR10 and TMR15 than that in TMR5. Concentration of $NH_3-N$ was highest (p<0.05) in the TMR10 followed by TMR15 and TMR5. Total volatile fatty acid was decreased (p<0.05) with increased cutting height. The digestibility of DM and neutral detergent fiber were highest (p<0.05) in TMR15, than those in TMR5 and TMR10, whereas acid detergent fiber digestibility was higher (p<0.05) in TMR5 than that in TMR10. The results showed that increasing cutting height, at least up to 10 to 15 cm, of whole crop barley forage at harvest (Yuyeon) may be beneficial for making silage for TMR formulation and increasing digestibility of DM and NDF.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.198-202
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• 2002

In this paper, stability of ultra precisio unit is analyzed, this unit is the kernel unit precision processing machine. According alteration of shape and material about stability investigation is performed. Through this stability investigation, trial is reduced in design and manufacture, at the time, we are accumulated foundation data for control.