• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.1-8
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• 2002

Cutting force is obtained as a sum of chip removing force and ploughing force. Chip removing force is estimated by multiplying specific cutting pressure by cutting area. Since ploughing force is caused from dullness of a tool, its magnitude is constant if depth of cut is bigger than a certain value. Using the linearity of chip removing force to cutting area and the constancy of ploughing force regardless of depth of cut which is over a certain limit each force is separated from measured cutting force and used to establish cutting force model. New rotation matrix to convert the measured cutting force in reference axes into the forces in cutter axes is obtained by considering that tool angles are projected angles from cutter axes to reference axes.. Spindle tilt is also considered far the model. The predicted cutting force estimated from the model is in good agreement with the measured force.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.21-28
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• 2004

In modem manufacturing industries such as the airplane and automobile, aluminum alloys which are remarkable in durability have been utilized effectively. High-speed machining technology for surface roughness quality of workpiece has been applied in these fields. Higher cutting speed and feedrates lead to a reduction of machining time and increase of surface quality. Furthermore, the reduction of time required for polishing or lapping of machined surfaces improves the production rate. Traditional milling process for high speed cutting can be machined with end mill tool. However, such processes are generally cost-expensive and have low material removal rate. Thus, in this paper, face milling cutter which gives high MRR has developed face milling cutter body for the high speed machining of light alloy to overcome the problems. Also vibration experiment to detect natural frequency in free state and frequency characteristics during machining are performed to escape resonance.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.7
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• pp.155-160
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• 2001

A milling process with 45 degree chamfered inserts produces a perfect flat surface only in theory. It is due to many unwanted factors including thermal effect, dynamic effect, the problem of the controller used and the problem of accuracy of the machine tool. In this study, introduced is a method to improve the surface roughness by redesigning of the chamfer angle of the insert, which traditionally has been 45 degree. First, the relationship between the fixed machine coordinate and the relative coordinate on the insert is derived. This transfer matrix is used to determine the new insert angle to maximize the flatness of the machined surface. A newly designed insert is manufactured, and used to carry out the experiment. It is proved that she insert designed by the proposed method produced a much flatter surface than a traditional one.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.81-85
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• 1993

정면밀링은 급속 가공을 매우 효율적으로수행할 수 있기 때문에 널리 사용되고 있다. 그러나 밀링커트는 단속 절삭 공구로서 절삭날의 단속절삭작용에 의한 변동적삭력과 여러날의 동시가공에의한 절삭력의 교란 때문에 절삭성이 기계가공에 문제가 되어 왔다. 이러한 문제점들을 해결하기 위하여 기계설계자들은 절삭 력의 교란에 의하여 일어나는 진동을 줄이기 위하여 기계구조의 강성을 증가시켰으나 이것은 비용이 많이 들게 되므로 공구 형상을 개선하여 안정된 절삭을 시도하였다. 본 연구에서는 절삭력 모델을 이용하여 변위 발생의 원인인 절삭력변동을 최소로 하는 커터의 형상을 3차원으로 최적 설계하였다. 최적 설계 제작된 공 구와 재래식 공구를 사용하여 절삭력, 공구수명, 표면조도를 측정하였다. 최적 설계 제작된 공구와 재래식 공구에 의하여 측정된 결과들을 비교 검토하여개발된 공구의 절삭특성을 규명하였다.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.19-27
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• 1995

Face milling is required to study cutting process with a view of multipoint cutter. This experimental study mainly deals with the single and multi-insert cutting characteristics using coated tool. Because metal cutting of the single and multi-insert has a large relation to the improvement of productivity, the economic cutting process can be achieved by the analysis of proper metal cutting mechanism. Therefore, machining characteristics of face molling in this paper has been studied by investigating the role of different insert number which is concerned with mean cutting force, the RMS values of AE(acoustic emission) signal, tool life and surface roughness in milling SS 41 and SUS 304. The cutting force and AE signal are monitored to make an analysis of cutting process. The surface roughness of the specimens machined by inserts of different numbers is measured at different speeds, feeds and depth of cut. The width of flank wear is also observed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.208-218
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• 1994

기계부품의 설계는 일반적으로 정면도, 평면도, 측면도로 구성되는 삼면도를 이용하여 이루어진다. 본 연구에서는 삼면도를 이용한 3차원 물체의 parametric design 방법을 제시한다. parametric design 기법을 구현하기 위 하여 인공지능기법을 이용하고, 삼면도로부터 입체를 생성하기 위하여는 기 하학적이고 단계적인 접근방법을 이용한다. 본 연구에서 제시한 방법은 삼면 도를 사용하여 설계하기 때문에 기존의 설계방법과 같을 뿐 아니라, 파라메 트릭 기능을 가지고 있어서 설계가 완성된 이후에 형상의 수정을 쉽게 할 수 있는 장점이 있다. 또한 기존의 2차원 도면을 입체모델(solid model)로 바 꾸어 줄 수 있는 기능도 수행할수 있다.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.12-19
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• 2011

Real-world accident cases were investigated to understand injury characteristics of the elderly driver. A total 10 cases of car-to-car frontal crash accidents from passenger car including SUV claimed to domestic car insurance company were reviewed. The injury characteristics of the elderly were analyzed from personal information (gender, age), medical treatment record (medical certificate, curative days), vehicle information (model, air-bag, seatbelt) and damage information. This study showed that elderly driver has higher possibility of thorax injury than non-elderly's. Moreover, Injury type and severity were more severe than non-elderly driver at similar type accident conditions. Also, elderly driver's medical treatment period needs 3 times more than non-elderly driver's.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.446-449
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• 2011

얼굴 인식 성능을 저해하는 환경으로 인한 축구 비디오에서의 낮은 선수 인식률과 제한된 해공간의 문제점을 해결하는 차원에서 본 논문에서는 다음과 같은 특징을 갖는 얼굴 인식 기반의 축구선수 인식 방법론을 제안한다: 1) 조명 변화에 민감하지 않은 얼굴 표현 방법인 ULBP를 사용하여 얼굴 인식 성능을 향상시킨다; 2) 얼굴 인식 성능을 저해하는 다양한 환경에서도 이미 강인한 성능이 검증된 SRC를 선수 식별 과정에 적용함으로써 안정적이고 높은 선수 식별 성능을 보장한다; 3) 클로즈업 샷뿐만 아니라 미디엄 샷의 정면, 준정면, 측면 얼굴 이미지를 대상으로 선수 식별의 해공간을 확장한다; 4) SRC의 점증적 갱신 학습 능력으로 축구 선수 얼굴 데이터베이스의 변화에도 능동적으로 적응한다. 실제 2010년 남아프리카 공화국 월드컵의 스페인 경기를 대상으로 제안된 방법론의 성능을 실험적으로 검증한다.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.63-68
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• 2003

Systematic geometrical variation method of hull forms, such as "1 -Cp", "Swinging" and "Lackenby" are widely used in the early stage of a new design from those of a similar parent ship, which shows a better performance through the model test and/or sea trials. This method is simple and easy to modify original hull forms without changing the main characteristics. The shape of the prismatic curie can be easily varied by these methods, however, the frame line shape in the body plan can′t be generated easily, when the section shapes are complicated or have discontinuities or the mismatch of the body plan and the stem and stern profiles. To overcome this drawback of the hull form variations, a simple and useful method has been proposed in the present study.

• Journal of Ocean Engineering and Technology
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• v.12 no.3 s.29
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• pp.103-111
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• 1998

This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.