• Journal of Biosystems Engineering
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• 제29권1호
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• pp.9-20
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• 2004

On the basis of design theory of soil inversion, two types of moldboard plow with secondary soil mover was designed and constructed to invert furrow slice at same position with furrow bottom. A series of soil bin experiment was carried to investigate the performance of prototypes. First prototype of new concept plow showed two kinds of problems during the preliminary experiment. For the plowing depth of 6cut the prototype did not invert the furrow slice, instead it just cut furrow bottom and the furrow slice returned to the original position. For the plowing depth of 8cm, there was soil clogging problem at the rear part of plow. From the above results it was concluded that the first prototype can not be used for the inversion of furrow slice at same position with furrow bottom. Second prototype could invert furrow slice at the same position with furrow bottom, but the performance was affected by soil moisture content soil hardness and plowing speed very much. For the higher soil moisture content, for the higher soil hardness and higher plowing speed, the prototype showed higher soil inversion performance. For the second prototype the inversion ratio was almost 100%, inversion angle was in the range of 90 to 100 degree and side displacement was less than 4 cm. But the furrow slice was not continuous, it was cut in the length of 30 to 40 cm. The reason why the furrow slice was cut in that length is blamed for the design of moldboard surface. The specific draft of prototype was in the range of 37.24 kN/㎡ to 42.14 kN/㎡ this value is a little higher than that of the conventional plow, or from 30.38 kN/㎡ to 33.32 kN/㎡. But the difference was not so big. The inversion performance of the second prototype for the field experiment was much better than that of soil bin experiment due to the better soil and operational conditions. Sticky and compacted soil conditions, and higher plowing speed was suitable for the plowing operation of the second prototype

• 인지과학
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• 제34권1호
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• pp.1-20
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• 2023

본 연구에서는 시각적 요인에 따라 한글 단어 재인에 미치는 공간주의의 영향을 살펴보았다. 시각적 요인에 따라 공간주의의 영향이 다르게 나타나는지 살펴보기 위해 단어의 시각적 복잡성(실험 1)과 단어의 밝기 대비(실험 2)를 조작하였다. 단어의 복잡성에 따라 받침이 있는 조건과 받침이 없는 조건으로 나뉘었고, 단어의 대비에 따라 대비가 높은 조건과 대비가 낮은 조건으로 나뉘었다. 어휘판단과제를 사용하여 공간단서가 표적 위치에 주어지는 경우(타당 시행)와 표적 위치에 주어지지 않는 경우(비타당 시행) 간의 수행 차이를 단서효과로 계산하여 주의의 영향을 살펴보았다. 실험 결과, 단어의 복잡성에 따라서는 단서효과가 유사하게 나타났으므로, 공간주의의 영향은 복잡성에 의해 달라지지 않는 것으로 해석되었다. 단어의 대비에 따라서는 고대비 조건에 비해 저대비 조건에서 단서효과가 크게 나타났다. 대비가 낮을 때 공간주의의 영향이 더 커지는 것은 자극의 신호를 강화시키는 공간주의의 기제로 설명되었다.

• Weed & Turfgrass Science
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• 제2권3호
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• pp.274-282
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• 2013

본 실험은 ISTA 변온 및 자연실온 환경에서 퍼레니얼 라이그래스 신품종의 종자 발아력, 초기발아속도 및 발아피크기간 등의 특성을 연구 비교해서 실무적으로 한지형 잔디의 설계, 시공 및 관리에 활용하고자 시작하였다. 실험 I은 ISTA 변온(8시간: 광조건, $25^{\circ}C$; 16시간: 암조건, $15^{\circ}C$), 실험 II는 $5-25^{\circ}C$로 유지되고 있는 실내 실온환경에서 수행하였다. 퍼레니얼 라이그래스 종자의 발아력, 초기발아속도 및 발아피크기간은 발아환경 및 품종에 따라 유의한 차이가 나타났다. 종자 발아력은 ISTA 변온환경에서 66.00-93.75%, 자연실온 환경에서 66.25-93.50%로 나타났다. 초기발아속도는 ISTA 변온에서 'Pennant II', 'Brightstar II', 'Sonata', 'Accent II' 품종, 자연실온에서는 'Pennant II' 및 'Brightstar II' 품종이 우수하였다. 품종별 발아피크 기간은 ISTA 변온 환경에서 1.48-5.65일, 자연실온에서는 2.17-10.63일로 나타났다. 발아환경에 관계없이 'Sonata', 'Pennant II' 및 'Brightstar II' 품종의 발아피크 기간이 짧았고, 발아피크 기간이 가장 긴 품종은 'Revenge GLX' 이었다. 본 실험 결과 종자 발아력, 초기발아속도 및 발아피크기간을 종합적으로 고려 시 ISTA 변온에서는 'Pennant II', 'Brightstar II', 'Sonata' 및 'Accent II' 품종이 우수하였다. 그리고 자연실온 환경에서는 'Pennant II' 및 'Brightstar II' 품종이 우수한 것으로 판단되었다.

• 대한인간공학회지
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• 제18권2호
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• pp.81-89
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• 1999

User's characteristics on the screen adjustment of color TV were studied. Two experiments were performed. In the first experiment, the characteristic of screen adjustment according to TV program, ambient luminance, and gender was investigated. Twenty subjects (10 females and 10 males) were participated in this experiment. Set points of brightness, contrast, tint, and color were measured on TV screen and analyzed. Brightness and contrast were significant on gender at significant level 0.01 and color was significant on gender at significant level 0.1. Tint was significant on program at significant level 0.01. The second experiment was performed to supplement the first experiment. The influences of ambient luminance, presented image, screen setting criteria, and gender were investigated. We simplified the first experiment in the second one. We restricted dependent variables (screen control variables) to only two, brightness and contrast. Other control variables were fixed to middle values. Brightness and contrast were significant on gender and screen setting criteria at significant level 0.01. In conclusion, we found that ambient luminance and presented image had no significant effects on TV screen adjustment and TV program had only a significant effect on tint. However, we found that gender and screen setting criteria had significant effects in most conditions.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.124-124
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• 2003

Citrus canker is very important disease in international trade of citrus. The disease was usually take place from late of June, and severe middle of July to middle of August, though disease occurrence was affected by environmental conditions. In pathogenicity test, three varieties, orange, lemon and kiyomi among 7 varieties, were succeptible, two varieties, satsuma mandarin and iwasachi, intermediate resistant. On the other hand, shiranuhi and yuzu were resistant relatively. The pathogen, Xanthomonas axonopodis pv. citri, grew well in PD broth adjusted to pH 7.0 at 26$^{\circ}C$. It's growth was best in medium containing group of monosaccharide as a carbon source and group of ammonium as a nitrogen source. Tow isolates were resistant to streptomycin among 11 isolates isolated from diseased leaves in field in Jeju-Do. The streptomycin sensitives isolate was controlled by in greenhouse test. On the other hand, the resistant and sensitive isolates were controlled by treatment with copper sulfate, the control value is 88.7％ and 90.6％, respectively.

• 동력기계공학회지
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• 제12권3호
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• pp.44-49
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• 2008

In this research, I would like to choose sliding distance and ventilated hole number which affect to the amount of wear of disk and pad as experiment conditions of 'the amount of wear' through wear test of motorcycle brake disk. Also, I analyze the amount of wear according to the variation of coefficient of friction by using design of experiment that is being widely used in diverse areas. With the tests of least, I present the correlation of each experiment condition. Therefore, I analyzed the variation of the amount of wear of disk and pad according to test factors such as ventilated hole number, applied load, sliding speed, and sliding distance in wear test of motorcycle brake disk by applying the design of experiment. Also, I analyzed quantitatively the influence of test factors through Taguchi Robust experimental design, response surface and examined the most suitable level and estimation of the amount of wear of disk. From these, I reached the following conclusions. response surface design, mathematical model was constructed about amount of wear of disk and pad. The amount of wear that decrease according to increase of ventilated hole number, and it's increase according to Increase of applied load, sliding speed, and sliding distance.

• Annals of Clinical Neurophysiology
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• 제8권1호
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• pp.44-47
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• 2006

Background: The present study used magnetoencephalography (MEG) to investigate the neural substrates for modified version of Treisman's visual search task. Methods: Two volunteers who gave informed consent participated MEG experiment. One was 27- year old male and another was 24-year-old female. All were right handed. Experiment were performed using a 306-channel biomagnetometer (Neuromag LTD). There were three task conditions in this experiment. The first was searching an open circle among seven closed circles (open condition). The second was searching a closed circle among seven uni-directionally open circles (closed condition). And the third was searching a closed circle among seven eight-directionally open circles (random (closed) condition). In one run, participants performed one task condition so there were three runs in one session of experiment. During one session, 128 trials were performed during every three runs. One participant underwent one session of experiment. The participant pressed button when they found targets. Magnetic source localization images were generated using software programs that allowed for interactive identification of a common set of fiduciary points in the MRI and MEG coordinate frames. Results: In each participant we can found activations of anterior cingulate, primary visual and association cortices, posterior parietal cortex and brain areas in the vicinity of thalamus. Conclusions: we could find activations corresponding to anterior and posterior visual attention systems.

• 한국기계가공학회지
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• 제12권6호
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• pp.69-76
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• 2013

This paper presents the development of the FCF method for the manufacturing of final products using numbers related to the minimum amount of work. The utilized product is a drum clutch, which is part of the transmission of an automobile. A double acting press is secured first and a prediction of the forming load on the practical material is made through an experiment with a plasticine model. Also, a finite element simulation using product shape and properties is performed, as well as a press experiment. A double acting press is manufactured that is suitable for a double acting experiment with a conventional hydraulic press(200 tons). A peripheral device for the press is additionally designed for experimental purposes. And, the press has as its essential points the drive speed, stroke control, etc., all of which influence the forming and is modified. Especially, a laser system is used for velocity measurement of two punches. The forming load of a practical material is predicted in order to derive a forming load formula for cold conditions on the basis of approximate similarity theory. Finite element analysis of the relative velocity ratio(RVR), etc., for most suitable flow defect(unfilling, etc.) prevention is achieved as well. The results are verified through a press experiment.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.284-293
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• 2022

After extracting the calcium component from the KR slag and the converter slag using ammonium chloride solution, the extract was reacted with carbon dioxide to synthesize precipitated calcium carbonate (PCC). In order to understand the effect of ultrasonic waves on calcium extraction from slags and calcium carbonate synthesis, the efficiency of calcium carbonate synthesis according to the with or without of ultrasonic waves was analyzed. The synthetic efficiency of PCC was investigated according to various experimental conditions, and the synthesized calcium carbonate was analyzed using XRD and SEM. In both slags, the amount of PCC decreased as the reaction temperature increased. The pH at the end of the experiment capable of synthesizing the maximum PCC in the carbonation reaction was 7 (irradiated with ultrasound) and 8 (irradiated without ultrasound), respectively. Because the pH of the extraction filtrate is different when irradiated with or without ultrasound, the pH was adjusted to 9 by injecting an additive (10 M NaOH) before the carbonation experiment, and then the experiment was performed. When calcium was extracted from KR slag, the crystal phase appeared as calcite regardless of the pH at the end of the experiment. However, when calcium was extracted from the converter slag and the pH was set to 7 at the end of the experiment, the crystal phase of PCC appeared as a mixture of calcite and vaterite.

• 산업기술연구
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• 제22권A호
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• pp.9-17
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• 2002

This analysis is aimed to find out how the conditions of secondary air injection affects the residence time and the turbulence energy of flue gas and flow field in a small incinerator. A commercial code, PHOENICS, is used to simulate the flow field of an Incinerator. The computational grid system is constructed in a cartesian coordinate system In this numerical experiment, an independent numerical variable is the conditions of secondary air injection and dependants are the residence time of flue gas and the mean value of turbulence energy in a primary combustion chamber. The flow field and the distribution of turbulence energy are analysed to evaluate the residence time of flue gas and the turbulence energy The computational results say that the tangential injection of secondary air make the residence time much longer than the radial injection and that the radial injection of secondary make turbulence much stronger than the tangential injection.