• 한국농공학회지
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• 제18권2호
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• pp.4096-4104
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• 1976

This experiment was carried out to investigate the efficient turning method which will be able to use every cutting methods, to calculate the width of the center field which must transpose from rotary cutting method to return cutting method, to investigate the effects of L/W and unit field on the operation efficiency. The results are summarized as follows: 1. In case of cutting in the outer field, the efficient turning method is the "$\alpha$" type turning method (half U-shaped turning method) at the first rotation, is the "$\beta$" type turning method (T-shaped turning method) at the second to fourth rotation. 2. In case of cutting in the inner field, the efficient turning method which takes the least turning time is the "a" type turning method ($\Delta$-shaped turning method). 3. The width of the center field (W') changes by the length-width ratio (L/W) and width (W), W' is 9.0m in case that L/W is 2.5 and W is 30m. 4. The larger L/W and area of unit field (A) become, the more operation efficiency (E) increases, and the limits that E is affected signicantly by L/W is 2 to 3.5 and A is within 5,000$m^2$. within 5,000$m^2$.

• 한국자동차공학회논문집
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• 제2권1호
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• pp.116-127
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• 1994

A method using the linear matrix algebra is developed in order to determine unknown external forces in linear structural analyses. The method defines a matrix which represents the linearity of the vibrational analysis for a structural system. The unknown external forces are determined by the operations of the matrix. The method is applied to find an engine motion in an automobile system. For a simulation process, an exhaust system is modeled and analyzed by the finite element method. The validity of the simulation is verified by comparing with the experimental results the free vibration. Also, an experiment on the forced vibration is performed to determine the damping ratio of the exhaust sysetm. Estimated model parameters(natural frequency, mode shape) are in accord with the experimental results. Because the method merely repeats the transpose and inverse operations of a matrix, the solution is extremely easy and simple. Moreover, it is more accurate than the existing methods in that there is no artificial assumptions in the calculation processes. Therefore, the method is found to be reliable for the analysis of the exhaust system considering the characteristics of vibrations. Although the suggested method is tested by only the exhaust system here, it can be applied to general structures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.417-418
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• 2006

CATIA V5 is one of the most preferred softwares in product design for domestic and industrial use. But with the development of the IT industry, design data by CATIA V5 can easily be hacked and stolen especially via the internet and through assistance storage medium. The design data could be protected through executive, physical and technical security system. The best way to maintain confidentiality of data from unauthorized access is to have a cryptosystem of the technical security. In this paper, a cryptosystem for the protection of design data was being proposed. The memory contains the file information made by the New and Open function of CATIA V5. No error can be expected even if the file changed before of after the application of Save and Open function, A cryptosystem was constructed in CATIA V5 by inserting crypto algorithm before and after the I/O process. The encryption/decryption algorithm of each function was based on the complex cipher, which applied permutation cipher and transpose cipher. The file security system was programmed in CAA V5 and Visual C++.

• 한국정밀공학회지
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• 제24권5호
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• pp.77-81
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• 2007

CATIA V5 is one of the most preferred softwares in product design for domestic and industrial use. But with the development of the IT industry, design data by CATIA V5 can easily be hacked and stolen especially via the internet and through assistance storage medium. The design data could be protected through executive, physical and technical security system. the best way to maintain confidentiality of data from unauthorized access is to have a cryptosystem of the technical security. In this paper, a cryptosystem for the protection of design data was being proposed. The memory contains the file information made by the New and Open function of CATIA V5. No error can be expected even if the file changed before of after the application of Save and Open function. A cryptosystem was constructed in CATIA V5 by inserting crypto algorithm before and after the I/O process. The encryption/decryption algorithm of each function was based on the complex cipher, which applied permutation cipher and transpose cipher. The file security system was programmed in CAA V5 and Visual C++.

• 로봇학회논문지
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• 제12권1호
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• pp.42-54
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• 2017

Using an inverse of the geometric Jacobian matrix is one of the most popular ways to control robot manipulators, because the Jacobian matrix contains the relationship between joint space velocities and operational space velocities. However, the control algorithm based on Jacobian matrix has algorithmic singularities: The robot manipulator becomes unstable when the Jacobian matrix loses rank. To solve this problem, various methods such as damped and filtered inverse have been proposed, but comparative studies to evaluate the performance of these algorithms are insufficient. Thus, this paper deals with a comparative analysis of six representative singularity avoidance algorithms: Damped Pseudo Inverse, Error Damped Pseudo Inverse, Scaled Jacobian Transpose, Selectively Damped Inverse, Filtered Inverse, and Task Transition Method. Especially, these algorithms are verified through computer simulations with a virtual model of a humanoid robot, THORMANG, in order to evaluate tracking error, computational time, and multiple task performance. With the experimental results, this paper contains a deep discussion about the effectiveness and limitations of each algorithm.

• 한국초전도ㆍ저온공학회논문지
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• 제10권2호
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• pp.34-37
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• 2008

According to the recent design of an HTS (High Temperature Superconducting) power transformer whose capacity is hundreds MVA, the rated current values of the low voltage side are generally over thousands amps. Considering the performance of the recent HTS wires, it is inevitable to use several HTS wires in parallel for large rated current. Lots of stacked HTS wires were fabricated and tested so far, and the results have showed that we have to transpose each wire in order to reduce the AC losses as well as to increase the current capacity. But many development programs about HTS transformers reveal that the transposition of the several wires during the winding process is quite difficult not only in case of the layer windings but also in case of the pancake type ones. So, we need transposed multiple HTS wire which we can handle like single wire or cable for the HTS windings of large capacity power transformer. We fabricated several kinds of samples of multiple HTS wire with transposition to apply it to the HTS windings of power transformer. The electrical characteristics such as critical currents or AC losses are analyzed by experiments in case by case. Finally we present the best design of a multiple HTS wire for power transformer.

• 한국초전도ㆍ저온공학회논문지
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• 제11권3호
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• pp.15-19
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• 2009

Recently, it is proposed to make striations on the YBCO coated conductor and to transpose each other as one of the solutions to decrease the perpendicular magnetization loss. For large power application using HTS, the stacked conductor packing the YBCO coated conductors should be used because single conductor is limited in flowing of demanded large current. In this paper, we research the affect of the striation and continuously transposed stacking geometry on the magnetization loss in perpendicularly exposed magnetic field. Several short samples having different number of striation and continuously transposed stack are prepared and tested in perpendicularly exposed magnetic field for the magnetization loss characteristics. The magnetization loss of striated sample was lower than sample without striation. The reduction effect on magnetization loss by the striation is obviously appeared in higher field and lower number of stack and decreased as increasing the transposed stacking number. Also, the reduction effect by transposed stack is obviously appeared in lower field at lower number of striation and isn't appeared at higher striation number and higher magnetic field.

• 대한전자공학회논문지SD
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• 제49권8호
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• pp.27-34
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• 2012

본 논문에서 H.264표준을 위해 2차원 $8{\times}8$ 순방향/역방향 정수 DCT 변환을 빠르고 효율적으로 계산할 수 있는 알고리즘을 제안한다. 순방향/역방향 변환은 간단한 시프트와 덧셈 동작을 사용하여 계산 복잡도를 줄였으며, DCT 연산에 메모리를 사용하지 않으므로 해서 불필요한 자원소모를 줄였다. 제안된 파이프라인 아키텍처의 최대 동작 주파수는 1.184GHz이며, 합성결과는 44864 게이트가 사용되어 25.27Gpixels/sec의 스루풋을 보여준다. 면적 비율에 비해 높은 스루풋으로 인해, 제안된 설계는 H.264/AVC 고해상도 비디오기술의 실시간 처리에 효율적으로 사용할 수 있다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 1부
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• pp.733-738
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• 2008

음열 음악은 쇤베르크가 창시한 20세기 음악의 중요한 작곡 기법중 하나이다. 이 음악은 범조적인 혹은 무조적인 특정을 가지며, 이로 인하여 독특한 현대 음악의 분위기를 생성하게 된다. 본 논문에서는 수학적 알고리즘을 이용하여 음열 음악을 생성하는 방법을 제안하고자 한다. 본 논문에서 소개하는 방법은 음열음악에 대한 쇤베르크의 엄격한 정의보다는 더욱 자유로운 형태를 띄지만, 전체 음악 내에서 12개의 음이 사용되어야 한다는 규칙은 만족한다. 이를 위하여 원형 음열 및 원형 음열의 전위과 전조로 구성되어있는 음열도표를 자유롭게 탐색하는 공간 채움 곡선을 이용한다. 임의의 공간을 한번만 탐색하는 성질을 가진 이 곡선을 사용함으로써, 음열 도표에 있는 모든 음을 한번씩 사용하면서도 적절한 반복성을 띄는 음악을 생성할 수 있다. 따라서 생성된 음악은 원래의 음열 음악의 특징인 범조성 및 무조성을 유지하면서도 현대음악에 친숙하지 않은 사람들에게도 보다 쉽게 접근하는 음악을 생성할 수 있다는 장점이 있다. 또한 다차원 공간 채움 곡선을 이용하여 음의 길이 및 세기까지 음열을 사용하는 더욱 확장된 형태의 음열음악을 생성하는 방법도 소개한다.

• 한국임상수의학회지
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• 제31권2호
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• pp.133-136
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• 2014

8 kg, 9개월령 중성화 수컷 시바 이누견이 양측 후지의 간헐적인 파행 증상으로 내원하였다. 검사를 통해 3단계의 양측 슬개골 탈구가 진단되었다. 대퇴 사두근의 정상 배열을 회복하기 위해서 상대적으로 비침습적인 조면의 위치를 재배열하는 독특한 수술 방법을 적용하였다. 이 과정은 경골 능선을 따라 경골 조면의 내측 피질골을 절개하고, 경골 조면을 외측으로 변위시키기 위해 경골 능선의 내측에 피질골 나사못을 장착하는 방식으로 이루어졌다. 수술 후 3개월 검사에서 양측 후지의 파행과 슬개골 탈구가 개선된 것이 확인되었다. 이 수술 기법은 골격이 미성숙한 환자에서 내측 슬개골 탈구를 치료하기 위한 효과적인 방법으로 고려될 수 있다.