• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.388-393
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• 1992

An infrared range finder using a self-mixing laser diode (SM-LD), which has been proposed and developed by the Authors, can measure not only a range of a moving target but its velocity simultaneously. In this paper, described is that the precise mode-hop pulse train can be obtained by employing a new signal processing circuit even when the backscattered light returning into the SM-LD is much more weaker. As a result, the distance to a tilted square sheet made from aluminium or white paper, which is placed 10 cm through 60 cm from the SM-LD, is measured with accuracy of a few percent even when the tilting angle is less than 75 degrees or 85 degrees, respectively. And in this paper, described is the range-image recognition of a plane object under the condition of standstill. The output laser beam is scanned by scanning two plane mirrors-equipped with each stepping motor. And we succeeded in the acquisition of the range-image of a plane object in a few tens of seconds. Furthermore, described is a feasibility study about the range-image recognition of a slowly moving plane object.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.723-728
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• 2003

The Ejector is used to get low pressure, and it has been applied to a lot of industry field like the heat engine, the fluid instrument power plant, the food industry, environment industry etc... because there are not any problem even it is mixed with a any kind of liquid, gas, and solid. The flow characteristics in ejector are investigated by PIV and CFD. The experiment using PIV measurement for mixing pipe's flow characteristics acquired velocity distribution, kinetic energy distribution, and whirlpool . (Condition : when mixing pipe's diameter ratio is 1:1.9, and the flux is $Q_{1}=1.136{\imath}/s$, $Q_{2}=1.706{\imath}/s$, $Q_{3}=2.276{\imath}/s$. Based on the PIV and the CFD results, the flow characteristics in ejector are discussed, and it shows the validity of this study.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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• pp.87-91
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• 2008

The study examined fire resistance of concrete followed by change of mixed rate in PP and NY composite fiber and the results were as follows. In the event of fluidity in concrete not set, plane satisfied 600±100, its target slump flow, and fluidity was reduced as organic fiber's mixed rate was increased. Air amount satisfied 3.0±1.0, its target air amount, and didn't have distinct differences in reduction and increase according to organic fiber's kind and change of its mixed rate. However, it had a tendency that fluidity was reduced as the mixed rate was increased. In characteristics of hardening concrete, the 28th day compressive strength followed by organic fiber's kind and change of its mixed rate didn't have a lot of differences and satisfied high strength scope as about 70MPa. In spalling characteristics after fire resistance test, spalling was happened in non-mixture, plane combination, and P1N0. In other combinations, spalling resistance was happened. The relic compressive strength rate was 56%, the best condition, in P3N1(PP0.03%, NY0.01% compositeness) mixing PP fiber with NY fiber at once.

• 한국분무공학회지
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• 제21권1호
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• pp.29-36
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• 2016

The effect of high ambient temperature and pressure conditions on the combustion performance of n-butanol, n-heptane and its mixing fuel (BH 20) were studied in this work. To reveal this, the closed homogeneous reactor model applied and 1000-1200 K of the initial temperature, 20-30 atm of initial pressure and 1.0 of equivalence ratio were set to numerical analysis. It was found that the results of combustion temperature was increased and the ignition delay was decreased when the ambient conditions were elevated since the combustion reactivity increased at the high ambient conditions. On the contrary, under the low combustion temperature condition, the combustion pressure was more influenced by the ambient temperature in the same ambient conditions. In addition, the total mass and the mass density of tested fuels were influenced by the ambient pressure and temperature. Also, soot generation of mixing fuel was decreased than n-heptane fuel due to the oxygen content of n-butanol fuel.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.722-727
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• 1996

A simple compost windrow-forming car and a compost tuner were developed at the aim of low cost manure management systems. The developed compost windrow- forming car is possible windrows formation at a short time. In order to be pulverized and mixed by upper and lower beaters at the windrow-forming, the condition of air and the mixing of materials to play a major role in composting is filled. This car can also utilized for a manure spreader by folding the windrow-forming cover. The developed compost turner is a type equipped with tractor rear-right side. Main specifications are 2.5m working width, overall length 3.3m and 45degrees conveyer inclination angle, 2 beaters for mixing and pulverization are equipped in front parts. Windrows of 2.5m width and 1.5m height are turned at the speed of 4.5-5.1m/min. In accordance with the above, by combining the compost windrow-forming car and the compost turner, a simple composting system for each farmer could be constructed by the low c st.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.145-149
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• 2000

We performed the geotechnical experiments of the hydraulic conductivity and compressive strength test with the stabilized soil in the laboratory, proved that it is useful to use the stabilized soil as an alternative for natural clay soil. Also, for mixing adding materials in the stabilized soil, it was determined that 1) the optimal mixing ratio of cement : bentonite : stabilizing agent was 90:60:1 of mass ratio(kg) for 1㎥ with soil, 2) it was also possible to use low quality bentonite(B\circled2) classified by swelling grade because of little difference from results of the hydraulic conductivity and compressive strength test with high quality bentonite(B\circled1). According to the results of the fixation ability of heavy metals(Pb$^{2+}$, Cu$^{2+}$, Cd$^{2+}$, Zn$^{2+}$) with soil and additives, authors can conclude that the higher pH condition had the more removal efficiency of heavy metals. B\circled1 and cement had especially high removal efficiency of heavy metals in a whole pH because of high alkalinity.alinity.

• 한국농공학회지
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• 제43권6호
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• pp.135-142
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• 2001

Laboratory experiment was performed to evaluate the influence of mixing conditions to the strength of solidified sandy soils with cement. The major physical factors considered in this experiment were the fine particles content(<$\sharp200%$), cement content(%) and water-cement ratio, and unconfined compressive strength test was performed on the samples at 7 and 28 cured day. The results of tests shows that when the cement content is relatively low (7~10 percents) the fine content in the sandy soils is very important, but when cement content is high the water-cement ratio became more important. It was appeared that in the range of the cement content of 7~10 percents, about 20~30 percents of fine content to the total sample weight is the optimum condition to get the maximum strength. In the case of the cement content of 13 percents, the strength of sample was considerably affected by the water-cement ratio rather than the fine content. In this paper, empirical equations were also developed and evaluated to verify the relationship among three factors by the multi-regression analysis.

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.155-162
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• 2017

Purpose: The objective of this study was to evaluate the biogas productivity of agricultural by-products (ABPs) based on their proximate composition. Specifically, the effects of proximate composition were investigated, and a new mixing method was developed using various ABPs that are difficult to digest for biogas production. Methods: Experiments were conducted to compare the biogas productivity between a single ABP and a mixture of ABPs that had the same proximate composition as the single ABP. To match the proximate compositions of radish waste and corn distiller's dried grains with solubles (DDGS), mixed ABPs were made from various ABPs. Biogas potential tests (BMP tests) were performed at an organic loading rate (OLR) of 2.5 g VS/L and a feed to microorganism ratio (F/M) of 0.5 under the mesophilic condition. Results: The individual ABPs (radish and corn DDGS) and the mixed ABPs (cabbage waste with skim milk waste, bean-curd waste with skim milk waste, and some others) produced similar amounts of biogas. Conclusions: The new mixing method based on proximate composition can be applied to other ABPs and organic wastes from factories and municipal waste treatment plants to develop renewable energy and effective waste treatment methods.

• 한국염색가공학회지
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• 제5권4호
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• pp.79-91
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• 1993

The purpose of this study is to prepare the newer, more comfortable of urea-formaldehyde resin finished fabrics. The methods of this study are by making examinations and comparisons the relations between the thickness, fabrics counts, weight, moisture regain and crease recovery of cotton and viscose rayon fabrics caused by condition of urea-formaldehyde resin finishing and warm retaining ability and warm-cool sense. The analytic results of thermal character in state of fabrics material finished with urea-formaldehyde are as follows: 1. The warm retaining ability has no correlation with mixing ratio of resin but the increase of the warm retaining ability has correlation with the increase of concentration of urea-formaldehyde resin. 2. The result pf multiple regression analysis for effect of physical property according to the concentration of resin to the warm retaining ability revealed as below. As the weight, thickness and density increase and moisture regain decreases, the warm retaining ability increases. 3. The qmax value has no correlation with mixing ratio of resin but the increase of the qmax value has correlation with the increase of resin concentration. In the end, the effect of it promotes cool sense. 4. The result of multiple regression analysis for effect of physical property according to the concentration of resin to the qmax value revealed as below. As he weight and thickness increase, the qmax value decrease. But, as the density and crease recovery increase, the qmax value increase.

• 한국자동차공학회논문집
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• 제23권4호
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• pp.402-409
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• 2015

In this study a quasi-dimensional model is developed to predict the combustion process and emissions of a GDI engine under ultra-lean conditions. Combustion of a GDI engine condition is modeled as two simultaneous processes to consider significant fuel stratification. The first process is premixed flame propagation described as burning in a hemispherically propagating flame. The second is diffusion-controlled combustion modeled as mixing of multiple spray zones in the burned gas region. Mixing is an important factor in ultra-lean conditions leaving stratified mixture of developing sprays behind the propagating premixed flame. Sheet breakup and Hiroyasu models are applied to predict the velocity of a hollow cone spray. Validation is performed against measured pressures and NOx and CO emissions at different load and rpm conditions in the test engine.