• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.221-222
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• 2006

In recent years, the demands of the aspherical glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. Glass lens is manufactured by the forming with high precision mold core. This paper presents the analysis of optimal grinding condition of tungsten carbide(WC, Co0.5%) using design of experiments(DOE). The process parameters are turbin spindle, work spindle, feedrate and depth of cut. The experiments results are evaluated by MINITAB software.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.188-192
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• 2000

In multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of each structures such as saddle, careg, and turret are simulated by MSC/NASTRAN, for the purpose of developing the effective design. The results of mode analysis and frequency analysis are visualized with PATRAN, and the mothod which can solve the resornance problem by eigenvalues and eigenvectors of each axe is developed as well.

• 한국연초학회지
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• 제5권1호
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• pp.11-17
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• 1983

The tobacco moth, Ephestia elutella Hubner (Lepidoptera: Pyralididae), was first reported one of the serious of stored tobacco in Korea in 1939 (8). In recent years, tobacco moth lavae were observed infesting in all of the tobacco storage warehouses in this Country. Adults of the tobacco moth for the seasonal occurrence were studied in the three and four regions in 1981 and 1982, respectively. This species was caught from early May to late October in all regions for both years. In 1981, the first emergence peak was in late May to late at Andong, early June at Suweon and the second one in middle August in both regions. In 1982, on the other hand, there were three peak times, late May and July, and middle September. But the relate size of the peaks was different in two years; the second peak showed about 66% of the total number of tobacco moths captured in the whole year in 1981 at Suweon and 59% of those at Andong, while the first peak had 32% at Suweon and 57% at Shintanjin in 1982. This difference in relative peak sizes was discussed.

• 한국연초학회지
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• 제3권2호
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• pp.129-130
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• 1981

The potato tuberworm, Phthorimaea operculella, is an occasional pest to tobacco plants in southern regions of Korea. In order to screen effective pesticides against the worm in tobacco leaves, pot and field experiments were carried out in 1981. In the pot experiment with a tobacco variety, Hicks, several effective organic phosphates (Dimecron- LQ 50, Dursban-WP 25, Ekalux-EC 25. Elsan-EC 47.5, and EPN-EC 45), out of 9 Pesticides tested, were solecte4 from their high mortality of more than 90%. Among these Pesticides Ekalux- EC 25 and Elsan- EC 47.5 were recommended to tobacco growers from their excellent efficacy in the field experiment with a tobacco variety, Burley 21.

• 한국전기전자재료학회논문지
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• 제19권11호
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• pp.1050-1054
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• 2006

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this research, optimal grinding condition was investigated using Microlens Process Machine for the development of aspheric glass lens which is to be used for mobile phone module with 3 mega pixel and 2.5X optical zoom, and tungsten carbide(WC) mold cote was manufactured using high performance ultra precision machining and the effects of DLC coating on the form accuracy(PV) and surface roughness(Ra) of WC mold core was evaluated.

• 항공우주시스템공학회지
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• 제8권1호
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• pp.1-6
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• 2014

The conventional hydraulic circuits for electro-hydrostatic actuators equipped with a single-rod cylinder can oscillate under overrunning load conditions. In this paper the oscillation problem encountered in the conventional hydraulic circuits for EHAs is analyzed and it is shown by simulation results that this problem can be solved by employing a counter balance valve instead of a pilot-operated check valve generally used in the conventional hydraulic circuits.

• Journal of Ginseng Research
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• 제13권1호
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• pp.119-122
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• 1989

phenological study on the oviposition, emergence, and flight activity of the African mole cricket adult has been made to obtain basic information for management of pest populations in ginseng fields. The flight activity, as monitored by the blarklight trap, seemed to be initiated depending on the sunset time and lasted about 2-2.5 hours. The trap data (1984-1988) showed that the adult flight of the species occurred twice a year, from early May to late June(Spring flight) and from late August to mid October(Fall flight) during which usually more crickets were trapped than during the former period. The number of females trapped was greater than that of males regardless to the flight period, i.e., females comprised 72.2%, 83.9%, and 73.3% of the total catches in 1984, 1985, and 1986, respectively. Adults emerged from late August to mid October and laid eggs from mid May to mid July the next year, indicating that the spring and fall flights correspond to the oviposition and emergence period, respectively.

• 한국응용곤충학회지
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• 제29권2호
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• pp.132-135
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• 1990

Anopheles quadrimaculatus( Say) 자매종 간의 미토콘드리아 DNA의 제한효소 절단부위변이를 Aedes albopictus의 마토콘드리아 cDNA를 probe로 이용하여 조사하였다. DNA hybridization에 의해 두 속간에는 mtDNA 영기서열의 상당한 상동성이 있음을 알 수 있었다. 개체 모기로부터 분리한 DNA를 제한효소를 사용하여 절단한 결과 자매종간에 다른 양상을 볼 수 있었으며 Hind III에 의한 mtDNA 절편만으로도 자매종들을 동정할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.452-452
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• 2008

Abstract Head-mounted displays(HMD) are being developed and marketed in growing numbers for a variety of applications. Though most commonly associated with entertainment applications other applications are also being developed. The field vision on the display screens is expanded by the optical system producing an imaginary screen that appears to be positioned several meters in front of the viewer. In this study, the mold core for the prism lens of HMD was processed by fly-cutting method, and the form accuracy of the mold core was measured.

• 한국기계가공학회지
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• 제5권4호
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• pp.41-45
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• 2006

In recent years, the demands of the aspheric glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. Glass lens is manufactured by the forming with high precision mold core. This paper presents the analysis of optimal grinding condition of tungsten carbide(WC, Co 0.5%) using design of experiments(DOE). The process parameters are turbin spindle, work spindle, feedrate and depth of cut. The experiments results are evaluated by MINITAB software.