• 센서학회지
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• 제8권2호
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• pp.139-147
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• 1999

본 논문에서는 관성 항법 장치 및 동작 제어 장치 능에서 회전 각속도를 검출하기 위하여 널리 사용되는 동조 자이로스코프의 새로운 각속도 검출방법을 제시하였다. 제안된 방법은 자이로스코프의 모델을 사용하여 재평형 루프의 설계를 수행함으로써 기존의 PI제어 방법만을 사용하였을 경우보다 외부 입력에 대하여 속도 검출을 위한 픽업단의 회전각도가 과도 및 정상 상태에서 작은 검출각을 유지시킨 상태에서 입력 각속도를 검출할 수 있으며 이에 따라 자유 자이로스코프의 기계적인 변경 없이도 시스템의 동작 범위를 매우 넓히는 것이 가능함을 보였다. 제안된 방법을 사용한 동조자이로스코프 시스템의 모델 및 전달 특성을 제시하였으며 최종적으로 컴퓨터 모의실험 모델 및 그 결과를 제시하여 그 타당성을 확인하였다.

• 한국잠사곤충학회지
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• 제16권1호
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• pp.49-55
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• 1974

추기에 있어서의 가지뽕 수확방법에 대하여 연구한 결과를 들면 다음과 같다. (1) 초추잠기에는 누애의 사육양에 따라서 왜소지 또는 정상지조를 1∼2본간벌수확을 하거나 지조하부에서 일부적엽수확을 하는 것이 좋다. (1) 4영기에 있어서는 왜소지간벌, 정상지조의 일부간벌 또는 중간벌채, 지조하부에서의 적엽 등 어떤 방법이나 수양에는 별 영향이 없기 때문에, 엽임, 노력관계들을 참작하여 이들 방법으로 수확하도록 하는 것이 타당할 것 같다. (3) 5영기에는 수량도 적지 않고 노력이 적게드는 수확방법, 즉 뽕밭의 한쪽부터 차례로 각주의 지조전부를 중간벌채수확 해가는 방법으로 수확을 하는 것이 가장 실용적이다. (4) 추잠기 또는 만추잠기에 가지뽕으로 중간벌채수확을 한 후의 잔조에서 적엽을 할 때에는 여름베기를 한 뽕나무나 봄베기를 한 뽕나무나 가리지 않고 노력이 덜 들고 간편한 훑어 따기로 하여도 무방하다.

• 대한수의학회지
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• 제39권6호
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• pp.1210-1217
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• 1999

This study was carried out to develop a newly designed ovum pick-up(OPU) instrument for ultrasound-guided transvaginal follicular aspiration in cows. This new instrument consists of out- & inner-layer stainless pipes and a grip with a trigger(hand) switch. Some gauge types of disposable needles and tubes can be attached to this inner pipe. With this instrument, while grasping an ovary with one hand, the other hand can handle in apiration and vacuum on/off with the least assitant's help. With this instrument the mean recovery rate of bovine follicular oocytes was 45.2%. In recovered oocytes, usable oocytes(Grade I & II) were 30.4% and this rate meant 1.4 oocytes per ovary. For 30 days after initial aspiration with this instrument, some adverse effects such as adhesion, hemorrhage, hematoma and other mass formation in/with ovaries were also examined by rectal examination, ultrasonographic and endoscopic images. Adhesion was found in one ovary 1 week after aspiration, and hemorrhagic lesion was found 1-2 days and petechia were found 3-5 days after aspiration and there was no remarkable adverse effects. It was found that this instrument could be applicable and safe for ovum pick-up in cows.

• 펄프종이기술
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• 제42권1호
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• pp.26-34
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• 2010

Effects of drying condition (IR radiation) on the optical properties and the printability of coated paper were elucidated at various latex sizes and low and high coating color concentrations. It was found that the smaller latex provided better rheology and higher dry and wet pick strength than the larger one. The high solids coating resulted in higher paper gloss and smaller roughness than the low solids coating, even though the clay addition was reduced by 20 parts in the high solids coating. Increasing IR radiation prohibited binder migration into the base paper. Thus it improved binder distribution and decreased pores in the coated layer, resulting in the increased dry and wet pick strength and the improved printing gloss. On the other hand, the color trapping and ink set-off was impaired with increasing IR radiation. Print mottle index passed through a maximum with increasing IR radiation.

• 펄프종이기술
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• 제34권1호
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• pp.22-29
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• 2002

The coated paper was greatly affected by the basic physical properties of the binder as well as the amount of the coating formula. High glass transition temperature (Tg) of the styrene-butadiene (SB) latex, selected as the binder in our study, gave the high stiffness to the coated paper, but lowered the binding force and print gloss. The average particle size of the SB latex also greatly affected to the coated paper so that the smaller particle size improved the rheological property of the coating formula and increased the binding force and print gloss. Another property of the SBR latex, gel content, was important because when its value was small, the latex was easily deformed at the high temperature and increased air permeability to the coated paper. Therefore, the lower gel content consequently resulted in the higher blistering resistance, especially in the web paper. The larger portion of the SB latex in the coated formula improved the binding force and print gloss, but decreased the ink set-off and ink-trapping to the coated paper. The heavier coating improved optical properties such as opacity, paper gloss and paper smoothness, to the coated paper.

• 산업공학
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• 제10권1호
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• pp.155-167
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• 1997

The purpose of this study is to develop the program for efficient operation of a multi-functional surface mounting device(SMD) which mount various components on a printed circuit board(PCB). These components are provided by diverse types of feeders such as cassette, stick and tray feeders. The SMD has one or two heads. In the SMD, the positions of PCB and feeders and fixed, and the head moves to pick up a component from a feeder and to mount it on the PCB. The number of lanes occupied by each feeder and the nozzle used for each component can be different. We develop an off-line program to minimize the cycle-time of the SMD by studying the optimal assignment of feeders and the optimal mounting sequence of components. Graphical User Interface(GUI) is also developed. Additionally, we consider the line balancing problem which appears when two SMDs are used sequentially.

• 산업공학
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• 제10권1호
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• pp.57-65
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• 1997

Less researches on AGV(Automated Guided Vehicle) path configurations have been conducted so far while more studies have been placed in determining AGV guide path directions and pick-up/drop-off station locations, and routing/dispatching/scheduling strategies. In practice plenty of concerns fall in preventing deadlock and simplifying AGV system control through an appropriate AGV path configuration. In order to meet those requirements, a new AGV path configuration, inter-loop stocker type is introduced here. The stocker serves as relaying material between loops as well as stocking material. Automated material handling systems using AGVs play an important role in semiconductor industry including TFT LCD and memory/non-memory chip. A practical example of implementing the inter-loop stocker concept successfully in the TFT LCD fab is presented in this paper.

• 한국인쇄학회지
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• 제15권2호
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• pp.25-40
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• 1997

This research was carried out to investigated the effect of base paper and latex binder on printability and obtical properties of coated paper. Especially, it examined the effect of th pH of vase paper surface and functional groups of latices on the interactions between coating color components and on the structure of coated layer. It was found that the behavior of coating color containing amphoeric latex depends on the pH in the boundary region between coating color and base paper. Thus, the coating color formulated with amphoteric latex formed bulky coating layer by inducing stronger interaction between paper surface and coating components than the coating color with anionic latex. The coated paper with amphoteric latex showed better optical properties (i.e.gloss and optical) and printability (i.e. ink receptivity, wet ink receptivity, and ink set off) than the conventional anionic latex in the acidic and alkaline paper. However, dry pick strength of the coated paper was less decreased. This result indicated that amphoteric latex could also be applied practically to the alkaline paper.

• 펄프종이기술
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• 제29권3호
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• pp.87-94
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• 1997

As the paper market becomes more and more competitive, more mills will want to switch to alkaline papermaking to take advantage of the Vowing demand. Many papermakers have tried to do this without success in the past much like the American papermakers did in the late 1970's. The Problem is that runnability Problems occur, drainage slows, Presses pick drying becomes more difficult and sheet quality suffers as a result Sheet holes and breaks occur, and runnability becomes a real operating problem. Converting to alkaline papermaking is not as simple as turning off the alum. We must be aware of the numerous factions that alum served at acid pH and provide alkaline alternatives. It is the purpose of this paper to discuss methods of deposit control via charge neutralization and system control at alkaline pH. This article explains the concept as well as the measurement and control. The resultant benefits are seen in runnability, quality and profitability for the papermaker.

• 펄프종이기술
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• 제39권2호
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• pp.25-30
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• 2007

Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.