• 한국잠사곤충학회지
• /
• 제13권2호
• /
• pp.151-154
• /
• 1971

In the silkworm egg production, cutting of the cocoon's edge formed by silkworms forced to aid the emergence, and emergence is related to the amount of alkaloid liquid in the sucking stomach in certain varieties. In this study, there was no difference between cutting of portion and sex, and no significant between cutting of both sides and one side cocoons when comparing their emergence ratio. Expenditures and emergence ratio between both sides and one side cutting off must be studied in coming future.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
• /
• pp.179-184
• /
• 2001

The mechanism of the aerosol generation consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without cutting in turning operation. These models were based on the spin-off mechanism and verified good for modeling the process. However, in real machining, the cutting tool destructs the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence the aerosol generation mechanism should be explained with splash model as well as spin-off.

• 한국정밀공학회지
• /
• 제19권12호
• /
• pp.93-99
• /
• 2002

The mechanism of the aerosol generation generally consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without real cutting in turning operation. These models were based on the spin-off mechanism, and verified good for modeling the process. However, in real machining, the cutting tool destroys the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence that the aerosol generation mechanism in real machining should be explained with splash model as well as spin-off.

• Smart Structures and Systems
• /
• 제24권3호
• /
• pp.345-360
• /
• 2019

The shear keys are set in a seismic isolation system to resist the long-term service loadings, and are cut off to isolate the earthquakes. This paper investigated the influence of shear keys on the seismic performance of a vertical spring-viscous damper-concave Coulomb friction isolation system by an incremental dynamic analysis (IDA) and a performance-based assessment. Results show that the cutting off process of shear keys should be simulated in a numerical analysis to accurately predict the seismic responses of isolation system. Ignoring the cutting off process of shear keys usually leads to untrue seismic responses in a numerical analysis, and many of them are unsafe for the design of isolated structure. And those errors will be increased by increasing the cutting off force of shear keys and decreasing the spring constant of shear keys, especially under a feeble earthquake. The viscous damping action postpones the cutting off time of shear keys during earthquakes, and reduces the seismic isolation efficiency. However, this point can be improved by increasing the spring constant of shear keys.

• International Journal of Precision Engineering and Manufacturing
• /
• 제4권1호
• /
• pp.49-55
• /
• 2003

This paper presents the experimental results to verify the environmental consciousness with economic balances due to cutting fluid behaviors and effectiveness in machining process. The cutting fluid improves the productivity through cooling, lubricating effects, however its environmental impact also increases according to the cutting fluid usage. The primary mechanism in this study is the spin-of motion of cutting fluids away from the rotating workpiece. In this study some machining parameters are adopted to analyze the productivity as well as environmental impact. This study provides the criteria for the resonable cutting fluid usage quantitatively to develop the environmentally conscious machining process.

• International Journal of Precision Engineering and Manufacturing
• /
• 제6권3호
• /
• pp.3-7
• /
• 2005

This paper presents the experimental results to verify the atomization characteristics and environmental impact of cutting fluid. Even though cutting fluid improves the productivity through the cooling and lubricating effects, environmental impact due to cutting fluid usage is also increased on factory shop floor. Cutting fluid's aerosol via atomization process can generate human health risk such as lung cancer and skin diseases. Experimental results show that the generated fine aerosol of which particle size less than 10 micron appears near working zone under typical operation conditions. The aerosol concentration also exceeds NIOSH regulations. This research can be provided as a basis of environmental impact analysis for environmental consciousness.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 추계학술대회 논문집
• /
• pp.37-42
• /
• 1997

Off-line feed rate scheduling is an advanced methodology to automatically determine optimum feed rates for the optimization of NC code. However, the present feed rate scheduling systems have lim~tations to generate the optimized NC codes because they use the material removal rate or non-generalized cutting force model. In this paper, a feed rate scheduling system based on an improved cutting force model that can predrct cutting forces exactly in general machining was presented. Original blocks of NC code were divided to small ones with the modified feed rates to adjust the peak value of cutting forces to a constant vale. The characteristic of acceleration and deceleration for a given machrne tool was considered when off-line feed rate scheduhng was performed. Software for the NC code optimization was developed and applied to pocket machining simulation.

• 한국정밀공학회지
• /
• 제20권2호
• /
• pp.50-57
• /
• 2003

This paper presents the experimental results to verify the atomization characteristics and environmental impact of cutting fluid. Even though cutting fluid improves the productivity through the cooling, Lubricating effects, environmental impact due to cutting fluid usage is also increased on factory shop floor Cutting fluid's aerosol via atomization process can be affected human health risk such as lung cancer and skin diseases. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near working tone under typical operational conditions. The aerosol concentration also exceeds NIOSH regulations. This research can be provided a basis of environmental impact analysis fur environmental consciousness.

• 한국정밀공학회지
• /
• 제27권3호
• /
• pp.9-17
• /
• 2010

The FPCB is used for electronic products such as LCD display. The process of manufacturing FPCB includes a cutting process, in which each single FPCB is cut and separated from the panel where a series of FPCBs are arrayed. The most-widely used cutting method is the mechanical punching, which has the problem of creating burrs and cracks. In this paper, the cutting characteristics of the FPCB have been experimented using Nd:YAG DPSS UV laser as a way of solving this problem. To maximize the industrial application of this laser cutting process, test samples of the multilayered FPCB have been chosen as it is actually needed in industry. The cutting area of the FPCB has four different types of layer structure. First, to cut the test sample, the threshold laser cut-off fluence has been found. Various combinations of laser and process parameters have been made to supply the acquired laser cut-off fluence. The cutting characteristics in terms of the variation of the parameters are analyzed. The laser and process parameters are optimized, in order to maximize the cutting speed and to reach the best quality of the cutting area. The laser system for the process automation has been also developed.

• 콘크리트학회지
• /
• 제2권1호
• /
• pp.79-90
• /
• 1990

철근 콘크리트 보의 인장철근이 합리적인 위치에서 체단(Cutoff)되지 않으며, 응력집중 및 부재의 극한강도가 저하되는 등의 문제가 발생될 수 있다. 따라서, 본 연구에서는 이러한 상황에 부합되는 실제건물을 대상으로 실물크기(Full Scale) 및 모형 실험을 함으로써 체단점에서 발생되는 파괴양상과 휨 강도, 실물, 시험체와 모형 시험체의 파괴 진전 상황등을 비교\ulcorner분석하고, 동시에 유한요소법에 의한 해석을 통하여 인장응력 분포 상태등을 검토함으로써 보 설계시 인장철근의 체단등에 관한 기토자료를 제공하고자 하였다. 실험 및 해석의 결과로부터, 체단부가 지점쪽으로 멀리 있을수록 최대내력의 감소는 물론 인장응력의 집중현상등이 나타나고 있는 바, 보부재의 설계시 인장철의 체단보에 대해서는 세심한 주의가 필여하리라 사료된다.