• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
• /
• pp.454-459
• /
• 2000

The high hardened materials that are remarkable in aspects of durability have been used for die and mold industry. As the high hardened materials are hard to machine, the high-speed machining is essential to manufacture these materials. Currently, in the general turning and milling, experiments to the tool wear monitoring have studied, but those have not applied in high-speed machining. In this study, the cutting mechanism was analysed by the cutting force according to cutting conditions, and the parameters to monitor the tool wear were selected from the tendency of the cutting force and acceleration according to cutting length in the high-speed machining of the high hardened materials(STD11).

• 한국공작기계학회논문집
• /
• 제13권2호
• /
• pp.127-132
• /
• 2004

In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, the new machining technologies which take environmental aspects into consideration are being developed. Recently the research institutions have established application method for dry, semi-dry, oil-mist and compressed cold air machining. In this paper the performance of new compressed cold air system for environmentally conscious machining is investigated and machinability of dry and new compressed cold air machining is evaluated. A series of tests are carried out by using measuring equipments in condition of dry and compressed cold air machining.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.16-21
• /
• 2002

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation fer the HMC is not sufficiently performed and the efficient cutting conditions aren't selected, a great loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented from the analysis of acceleration in idling. The Machinability fur the TiAlN coated flat end mill and STD11( $H_{R}$C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions and slenderness ratio and a low response of tool dynamometer in high speed is proved. The resonance spindle speed is identified through the tool wear and natural frequency test.t.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 추계학술대회 논문집
• /
• pp.178-181
• /
• 2005

Quaternary Ti-Si-C-N coatings were deposited on WC-Co substrates by a hybrid coating system of arc ion plating (AIP) and sputtering techniques using Ti and Si targets, in an $Ar/N_2/CH_4$ gaseous mixture. The crystallinity, bending status, and microstructure of the Ti-Si-C-N coatings were measured by X-ray diffractometer (XRD) and X-ray photoelectron spectroscope (XPS), The micro-hardness of Ti(C,N) and Ti-Si-N coatings were about 30 and 40 GPa, respectively. As the Si was incorporated into Ti(C,N) coatings, the Ti-Si-C-N coatings having Si content of $8.9\;at.\%$ showed the maximum hardness value of about 55 GPa. In this work, the microstructure and mechanical properties of Ti-Si-C-N coatings were systematically investigated.

• 한국소음진동공학회논문집
• /
• 제11권9호
• /
• pp.475-485
• /
• 2001

A study on the structural analysis of the composite laminated cylindrical shell which has simply supported boundary conditions at both ends, was performed. The results were used into the neural networks. Neural networks identify the load characteristics of the composite shells. Momentum Backpropagation which the learning rate can be varied was developed. Input patterns consist of strains at 9 side points which is divided equally. Output layers are the load characteristics. Developed program was used for the training. The training with variable learning rate was converged close to real oad characteristics. Inverse engineering can be applicable to the composite laminated cylindrical shells with developed neural networks.

• 대한기계학회논문집A
• /
• 제25권9호
• /
• pp.1444-1451
• /
• 2001

The evolutionary structural optimization(ESO) method has been under continuous development since 1992. The bidirectional evolutionary structural optimization(BESO) method is made of additive and removal procedure. The BESO method is very useful to search the global optimum and to reduce the computational time. This paper presents the ranked bidirectional evolutionary structural optimization(R-BESO) method which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO.

• 무역상무연구
• /
• 제37권
• /
• pp.217-250
• /
• 2008

The International Ship and Port Facility Security (ISPS) Code which was developed as the main response of the shipping sector to the miserable event of 11 September 2001 came into effect on 1 July 2004. The ISPS Code designed to detect and eliminate security threats affecting ships and port facilities used in international trade will significantly impact not only on the management and operation of the shipping industry but also on maritime law despite the fact that it is the regulatory framework of public law. It is expected that implementing the ISPS Code will contribute to reinforcement of maritime security on the one hand. However, on the other hand, more intensified security inspection and control measures of port states will also cause delay and additional costs which cause uncertainty in allocating security risk and cost between the contracting parties. Therefore, it is desire to insert new security clause dealing with main security issues or adapt existing clauses to new shipping environments to minimize disputes.

• 자원ㆍ환경경제연구
• /
• 제14권3호
• /
• pp.627-653
• /
• 2005

본 연구는 외국의 환경규제 수준과 한국의 수출 사이의 관계에 대한 실증분석으로서, 82국가에 대한 2001년 수출자료를 이용하였으며 중력모형을 기본모형으로 하여 회귀분석한 결과 다음과 같은 결과를 얻었다. 첫째, 전체산업에 대하여 환경규제가 수출에 미치는 효과를 분석한 결과 환경규제가 강한 나라일수록 우리나라의 수출이 증가하고 있다. 둘째, 환경오염산업으로 분류된 17개 산업에 대하여 개별적으로 분석한 결과, 대체로 환경규제변수의 영향이 존재하지만 개별 산업에 따라 그 영향의 정도는 다르며 전체적으로는 매우 큰 영향이 있다고 보기는 힘들다.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 추계학술대회 논문집
• /
• pp.292-296
• /
• 2002

In the present investigation, the improvement of processing efficiency in the high speed machining of GC250 is explored. This study is to evaluate the tool performance in difficult-to-material using the new developed tool. Tool performance evaluation are conducted by tool wear, surface roughness, chattering in machined surface. The tool wear of A type was smaller than B type. In type B tool the chatter mark was observed in machined surface. The good surface roughness was obtained in type A tool. Consequently, the tool performance of A type is better than B type.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1999년도 춘계학술대회 논문집
• /
• pp.123-127
• /
• 1999

This paper suggests the establishment of high-accuracy and high-efficiency machining method of scroll shape workpiece by using the feed control method. The cutting paths for machining the inside and outside surfaces of the scroll-shape workpiece are calculated, and the calculation method of the cutting chip areas based on the coordinate of the base circle is shown. A feed control method is proposed for a constant cutting area and cutting force. By machining test of scroll shape workpiece, The machined accuracy of wrap, tool wear, and surface roughness are evaluated. By this method, Reduction of the machining time and large increase of the efficiency can be expected.