• 대한안전경영과학회지
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• 제6권4호
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• pp.171-181
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• 2004

A multi axis whetstone polishing system, which uses the flow system of the stone polishing machine head, has been developed. The test results show that the defect by line contact polishing does not occur in both ends of the stone and that it came to trim smoothly. In terms of the surface roughness, the corresponding index was decreased by 3.6 times, improving the polishing effect greatly. It decreased significantly the dust and noise with the wet polishing. The factors of the duty evasion at production site can thus be solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

• 한국생산제조학회지
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• 제18권5호
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• pp.498-506
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• 2009

An experimental study was performed to select cutting parameters for better quality-products in hard metals such as steels. Usually, a hard metal can be cut with a rotary cutting knife and the process provides a good cutting quality result. However, the cutting machine is much sensitive in cutting conditions because of its complicated mechanism. By this reason, careful processing conditions must be taken to improve the quality of the products. This experimental study for better quality products with a rotary cutting knife was carried out with two main factors; cutting speeds and cutting and pooling forces. A two-dimensional profile measuring instrument is used to evaluate its cutting faces and the effects of processing factors are analyzed by a commercial software.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.189-195
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• 2004

It compared quality characteristics for the stone surface treatment system and its products. With the result, the flame burner equipment was mainly used to the surface treatment of granite, but it occurred greatly the high temperature, the rock fragment, the noise and dust. For the other side, the whetstone polishing machine for the polishing was a maintenance for the specific physical properties of stone, and it did not occur the stone fragment and the dust. The durability of the stone products due to the flame burner was investigated with that it falls to $20\sim25\%$ more than the surface treatment by the whetstone polishing. Share's hardness of the polishing products in the durability test showed more greatly index than the flame burner and conventional product. The polishing products of Pochon stone in the case of the abrasion resistance showed great more $15\%$ than the general products, more $9\%$ than the products by the flame burner.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.165-170
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• 2004

It used the flow system of the stone polishing machine head and it developed a multi axis whetstone polishing system. With the result, the defect by line contact polishing does not occur in both ends of the stone, and it came to trim smoothly. As the index of the surface roughness decreased to 3.6 times, the polishing effect improved greatly. It decreased greatly the dust and a noise with the wet polishing, and the factors of the duty evasion at production site were solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

• 한국정보과학회논문지:시스템및이론
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• 제28권1_2호
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• pp.90-102
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• 2001

리오더버퍼는 명령어를 비순차로 이슈하는 수퍼스칼라 파이프라인에서의 명령어 실행을 순차적으로 완료하는데 사용된다. 본 논문에서는 리오더버퍼에 의하여 발생할 수 있는 명령어의 스테그네이션(stagnation)을 효율적으로 제거시킬 뿐만 아니라 리오더버퍼의 크기를 감소시킬 수 있는 쉘터버퍼를 사용한 리오더버퍼 구조를 제안하였다. 시뮬레이션을 수행한 결과 리오더버퍼의 엔트리 개수가 8개에서 32개 사이일 때 쉘터버퍼는 단지 1개 또는 2개만 사용하여도 뚜렷한 성능 향상을 얻을 수 있음을 보여준다. 쉘터버퍼를 4개 사용했을 때는 2개만 사용했을 경우와 비교하여 주목할만한 성능 향상은 없었다. 이는 쉘터버퍼를 2개만 사용하여도 대부분의 스테그네이션을 제거하는데 충분함을 보여준다. 실행율의 손실이 없는 상태에서 2개의 쉘터버퍼를 사용하면 Whetstone 벤치마크 프로그램에서는 44%, FFT 벤치마크 프로그램에서는 50%, FM 벤치마크 프로그램에서는 60%, Linpack 벤치마크 프로그램에서는 75%의 리오더버퍼의 크기를 줄일 수 있었다. 쉘터버퍼를 사용했을 때 수행 시간 역시 Whetstone에서는 19.78%, FFT에서는 19.67%, FM에서는 23.93%, Linpack에서는 8.65%의 성능 향상을 얻을 수 있었다.

• 한국생산제조학회지
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• 제19권2호
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• pp.275-281
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• 2010

This research's goal is to process directly aspherics with big sagment and thin center thickness. If we can process directly aspherics with big sagment and thin center thickness, we think it greatly helps to reduce the time of developing optical system. We made very thin glass using diamond grinding whetstone regarding the trace of tool and the detailed drawing of tool super precisive aspherics that has 0.46mm center thickness and over $30^{\circ}$ segment, $0.1{\mu}m$ machining accuracy, 15nm surface accuracy. We think this research's result will be effective to open new market because it is applied not only cell phone optical system but also CCTV robot optical system, internet phone optical system. Also we expect to enhance the super strong brittle precisive process's possibility with super precisive processing technique that achieves 0.46mm glass center thickness as first in the world.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.144-147
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• 2015

big.LITTLE 구조는 고성능 코어와 저전력 코어를 조합하여 전력과 성능, 일석이조의 효과를 볼 수 있다. CPU의 연산에 집중된 벤치마크인 MP Whetstone과 MP Dhrystone을 통해 2개의 고성능 코어와 4개의 저전력 코어에서 가능한 모든 조합의 전력과 처리량을 분석하여 big.LITTLE 구조의 효율성을 확인할 수 있을 것으로 보인다.

• 대한임베디드공학회논문지
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• 제14권1호
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• pp.51-61
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• 2019

There are strict evaluation processes before using new processors to satellites. Engineers evaluate processors from various viewpoints including specification, development environment, and cost. From a viewpoint of computation power, manufacturers provide benchmark results with processors, and engineers decide which processors are adequate to their satellites by comparing the benchmark results with requirements of their satellites. However, the benchmark results depends on a test environment of manufacturers, and it is quite difficult to achieve similar performance in a target environment. Therefore, it is necessary to evaluate the processors in the target environment. This paper compares performance of a processor, AT697F/LEON2, in software testbed (STB) with three development boards of XC2V/LEON3, GR712RC/LEON3, and GR740/LEON4. Seven benchmark functions of Dhrystone, Stanford, Coremark, Whetstone, Flops, NBench, and MiBench are selected. Results are analyzed with hardware and software properties: hardware properties of core architecture, number of cores, cache, and memory; and software properties of build options and compilers. Based on the analysis, this paper describes a guideline for choosing processors for next generation satellites.

• 한국정밀공학회지
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• 제30권4호
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• pp.397-402
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• 2013

In this study, we carried out the each lines of section, using GC (green silicon carbide) whetstone, the SCM415 material which separated by after and before heat treatments process, in 3+2 axis machining centers for integrated grinding after cutting end mill works, the spindle speed 8000 rpm and feed rate 150 mm/min. For the analysis of the centerline average roughness (Ra), we measured by 10 steps stages. Using Finite element analysis, we found the result of the load analysis effect of the assembly parts, when applied the 11 kg's load on both side of the ATC (Automatic tool change) arm. The result is as follows. For the centerline average roughness (Ra) in the non-heat treatment work pieces, are appeared the most favorable in the tenth section are $0.510{\mu}m$, that were shown in the near the straight line section which is the smallest deformation of curve. In addition, the bad surface roughness appears on the path is to long by changing angle, the more inclined depth of cut, because the chip discharging is not smoothly.

• 자원환경지질
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• 제56권6호
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• pp.661-674
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• 2023

충남 태안 해역에서는 2014년 국내 수중발굴 역사상 처음으로 조선시대 선박이 발견되어 마도4호선으로 명명되었다. 마도4호선은 발굴된 유물을 통해 1417~1425년(태종~세종) 사이 나주에서 공물을 싣고 한양으로 가다 침몰한 조운선임이 밝혀졌다. 마도4호선의 선체에서는 공물로 적재된 총 27점의 미사용 숫돌이 발견되었다. 27점 숫돌은 모두 폭이 좁고 긴 막대기 형태이며. 길이, 폭, 두께 및 무게의 평균값은 각각 161.5mm, 36.1mm, 22.7mm 및 253.2g 이다. X-선 회절 분석 결과, 구성광물은 석영, 알칼리장석, 사장석으로 고해상도 디지털 실체현미경 분석 결과와 유사하다. 마도-2672와 2673의 평균 공극률은 각각 2.69%와 1.78%, 평균 표면 경도는 각각 807.2HLD와 834.5HLD로 공극률이 일정 이상 증가하면 표면 경도 감소에 영향을 미치는 것으로 해석된다. 이들은 모두 장석질 사암(Arkose)이며 SiO₂의 함량은 평균 74.51%로 숫돌로서 적합함이 확인되었다. 27점의 숫돌은 SiO₂의 함량을 기준으로 구분할 때, 중간 숫돌에 해당한다. 이들 숫돌은 크기와 무게가 작고 휴대하기 편리한 특징을 갖고 있어 비고정식 숫돌의 한 종류로 추정되며, 조선시대 무기 연마와 공예품 제작 등 특수분야에 주로 사용된 것으로 판단된다.