http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
개별검색 DB통합검색이 안되는 DB는 DB아이콘을 클릭하여 이용하실 수 있습니다.
통계정보 및 조사
예술 / 패션
<해외전자자료 이용권한 안내>
- 이용 대상 : RISS의 모든 해외전자자료는 교수, 강사, 대학(원)생, 연구원, 대학직원에 한하여(로그인 필수) 이용 가능
- 구독대학 소속 이용자: RISS 해외전자자료 통합검색 및 등록된 대학IP 대역 내에서 24시간 무료 이용
- 미구독대학 소속 이용자: RISS 해외전자자료 통합검색을 통한 오후 4시~익일 오전 9시 무료 이용
※ 단, EBSCO ASC/BSC(오후 5시~익일 오전 9시 무료 이용)
최근 급속히 증가하고 있는 Digital Content의 생성과 활용으로 인해 인터넷 기반의 Digital Content 유통이 활성화 되고 있다. 하지만 URL의 한계와 Content의 불법복제 및 무단변형과 같은 역기능이 나타남으로써 양질의 콘텐트 생산·유통이 저해되고 있다. 따라서 본 논문에서는 URN 기반의 DOI 식별체계와 Digital Content 보호를 위한 PKI 기반의 공개키 알고리즘, 그리고 콘텐트 제공자의 저작권을 보호하기 위한 Digital Watermarking과 DRM기술을 접목한 강인한 Digital Content 유통모델을 제안하고자 한다.
The cycloid speed reducer has an advantage of transmitting high torque, but is known to be unsuitable for high speed rotation. However, it is almost impossible in an analytical method to find a use limit speed when installing such a speed reducer in a transporter. In this research frictional loss power pursuant to the imposed torque and RPM by simulating the performance of a cycloid speed reducer with LS-DYNA. The maximum torque of the cycloid speed reducer is 3.5ton-m, so the comparison of analysis results between a case of 60rpm rotation and a case of 162rpm rotation with such a torque showed the following results. In the case of 60rpm rotation, the maximum stress appearing in the RV gear and the pin 'gear was 463㎫ and 507㎫. Lost power due to friction was 50㎾; In the case of 162rpm rotation, the maximum stress appearing in the RV gear and the pin gear was 550㎫ and 538㎫. Lost power due to friction was 175㎾, which was shown to be almost impossible to use.
최근 급속히 증가하고 있는 Digital Content의 생성과 활용으로 인해 인터넷 기반의 Digital Content 유통이 활성화 되고 있다. 하지만 URL의 한계와 Content의 불법복제 및 무단변형과 같은 역기능이 나타남으로써 양질의 콘텐츠 생산·유통이 저해되고 있다. 따라서 본 논문에서는 URN 기반의 DOI 식별체계와 Digital Content 보호를 위한 PKI 기반의 공개키 알고리즘, 그리고 콘텐츠 제공자의 저작권을 보호하기 위한 Digital Watermarking과 DRM기술을 접목한 Digital Content 유통모델을 제안하고자 한다.
A laser surface-melting alloying process using a laser beam is a new surface-hardening process of obtaining an alloying layer that melts the surfaces of substrates and alloying powder at the same time. This study used SKD61 hot die steel as a substrate and SKH51 powder as an alloying powder. The laser beam speed and the laser power were fixed at 70 mm/sec and 2 kW. The power feeding rate was changed from 0 rpm to 6 rpm (step: 1 rpm). The alloying layer showed high hardness (710~830 Hv), but cracks occur at a high powder feeding rate. Cracks occur at more than 5 rpm, and the lengths of cracks become longer as the powder feeding rate increases. Moreover, cracks were observed at the dendrite boundary, and dendrite protrusions were observed on the fracture surfaces. As the powder feeding rate increases, the concentration of the Mo, V, and W in alloying layer increase. The liquidus and solidus temperatures decreased by as much as 6 ℃ and 26 ℃. As a result of calculating the aspect ratio (penetration depth/width) of the molten zone, it was found that there is no difference as the powder feeding rate increases. Therefore, strain by solidification contraction was constant with an increase in the powder feeding rate, but cracks occur, and the number of cracks increases because the solidus temperature decreases and the ductility of alloying layer reduces.
Along with the development of various engineering technologies, the recent manufacturing technology and statistical quality control technology have made much progress. Statistical quality management technology is being researched to maintain and manage the quality of parts per million (PPM) level to satisfy the needs of customers. Among them, control chart is a technique to monitor the variation of various quality parameters. In particular, the defective rate control chart for monitoring fraction of nonconforming has a problem in that too many samples are required when fraction of nonconforming decreases to the PPM level. To solve this problem, there are various methods such as acceptance control chart, but it also has a limitation that it can be used only when the quality parameter is normally distributed. In this paper, we propose a method to manage the minimum defect rate of PPM level in the process where the quality parameter has non-normal distribution characteristics. First, we apply the Z<sub>P</sub> statistic that can represent the minimum defect rate with a small number of samples. Also, Burr<sub>ZP</sub> distribution is suggested by using Burr distribution that can fit most single-probability distribution. And Burr<sub>ZP</sub> distribution is used to show the performance of Burr<sub>ZP</sub> control chart using 3 sigma control chart method.