• Journal of the Korean Wood Science and Technology
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• 제15권4호
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• pp.64-68
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• 1987

To develope the utilities of the chestnut bur, which is wasted after harvesting chestnut in farmhouses, the feasibilities of adhesion(urea resin) extenders of the powder for plywood were examined. These experiments were implemented on experimental scale at Forestry Research Institute(Seoul) and on a plywood mill scale at Eugon Industrial Co LTD(Inchon) for more reliable data. In this paper, it was proved that the chestnut bur powder caused to rise the glue viscosity but the chaff powder to down reversely. The most effective mixing ratio were wheat flour 5kg, chaff powder: 5kg and chestnut bur powder. 5kg per 100kg of urea resin. At this condition, the viscosity were most appropriate (1,320 2,230 cps) for glue spreading operations, and the dry shear strengthes were most adequate(10.7-13.2kg/$cm^2$), wood failure ratio 82-88%). The chestnut bur powder, can be utilized for plywood adhesion extenders without any change of present process lines in plywwod mills.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.50-55
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• 2007

The purpose of this research is to enhance the luminance of the LED and to improve the implementation of color by mounting an array lens on the LED without special technology in process. The workmanship of key components considering the economical efficiency and the injection molding technology for high quality of the product are essential to achieve it. In this paper, the mold was computer-aided was designed and manufactured by CAM software (NX4) and high speed machining center. the applied final machining conditions were 3,000-5,000mm/min feed speed, 15,000-25,000rpm and ${\Phi}0.3mm$ ball end-mill. And the Flow analysis was performed using the mold flow software(MPI) in order to get uniformity of resin. Injection conditions acquired by the flow analysis and the injection experiment are as follows. The cylinder temperature is $220-260^{\circ}C$, the mold temperature is $70-80^{\circ}C$, the injection time is about 1.2sec, the injection pressure and velocity is each 7.8-14.7Mpa, and the injection velocity is 0.8-1.2m/sec.

• 한국정밀공학회지
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• 제23권6호
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• pp.151-159
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• 2006

This paper describes a design process of end-milling cutters: solid model of the designed cutter is constructed along with computation of cutter geometry, and the wheel geometry as well as wheel positioning data f3r fabricating end-mills with required cutter geometry is calculated. In the process, the main idea is to use the cutting simulation method by which the machined shape of an end-milling cutter is obtained via Boolean operation between a given grinding wheel and a cylindrical workpiece (raw stock). Major design parameters of a cutter such as rake angle, inner radius can be verified by interrogating the section profile of its solid model. We studied relations between various dimensional parameters and proposed an iterative approach to obtain the required geometry of a grinding wheel and the CL data for machining an end-milling cutter satisfying the design parameters. This research has been implemented on a commercial CAD system by use of the API function programming, and is currently used by a tool maker in Korea. It can eliminate producing a physical prototype during the design stage, and it can be used for virtual cutting test and analysis as well.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.151-156
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• 1995

This paper presents a methodology for real-time detecting and identifying the runout geometry of an end mill. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear,amplification of force variation and hence enlargement vibration amplitude. Form understanding of chip load change kinematics, the analytical sutting force model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the total cutting forces can be given as the algebraic multiplication of the Fourier transforms of the local cutting forces and the chip width density of the cutter. Experimental study are presented to validata the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance tolerance and surface quality for industriql application.

• 한국정밀공학회지
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• 제14권3호
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• pp.66-74
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• 1997

In a high speed and high precision vertical machining center, chatter vibration is easily generated due to unbalanced masses in rotating parts and changtes of cutting forces. In this paper, modal test is performed to obtain modal parameters of the vertical machining center. In order to predit the cutting force of endmilling process for various cutting conditions, a mathematical model is given and this model is based on chip load, cutting geometry, and relationship between cutting forces and the chip load. Specific cutting constants of the model are obtained by averaging forces of cutting tests. The interactions between the dy- namic characteristics and cutting dynamics of the vertical machining center make the primary and the secondary feedback loops, and we make use of the equations of system to predict the chatter vibration. The chatter prediction is formulated as linear differential-differene equations, and simulated for several cases. Trends of vibration as radial and axial depths of cut are changed are shown and compared.

• 한국조경학회지
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• 제33권5호통권112호
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• pp.114-122
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• 2005

Anyang city performed a design competition for the existing paper mill site and this design is the work that was submitted to that competition. The design instructions for the competition were about an organic site which had harmony of aboveground park and underground parking lot, establishment of park planning which is fit for the features of nearby areas, and security of proper parking space. This design criteria set the design concept to a new wave of Anyang by reflecting the design instructions of prize contest and features of the site and developed it as three waves. First, the eco wave, one of three waves, means that it compose the ecological healthy park and urban environment together with restoration and preservation of Suamcheon (stream), and futhermore the waves that the natural resource are maintained in a delicate ecological balance as the water resource of Anyang city are connected to the axis of mountain resource. Secondly, the emotion wave indicates that the wave toward culture and art emotional park that stimulates and fills up the emotion to makes impoverishing modems minds fertile. Thirdly, the health wave means the waves toward a park to keep the sound of minds and bodies of Anyang citizens, and healthy and sound life as well as the waves toward a park to contribute the healthy leap and development of Anyang. These three waves will enrich the park keeping the dynamic relationship mutually and will be a new culture and art code of Anyang city.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.561-563
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• 1999

The looper of a hot strip finishing mill is installed between each pair of stands and plays a key role to enhance the product quality of strip by controlling the tension and height of strip in each inter-stand. Though the conventional looper control has achieved the mass products of strip so far, it has difficulties not only tuning gains by means of errors which are caused by coupling effects between strip tension and looper angle both utilizing tension feedback. Therefore, the non-interactive control employing cross controller and tension feedback has been introduced in looper control system in order to overcome the coupling effects existing between tension and looper angle and track the reference tension efficiently. In this paper, we present the cross controllers which play a role to decouple reciprocal effects between tension and looper angle and show better performance.

• 유기물자원화
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• 제9권2호
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• pp.58-65
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• 2001

매립지의 재자연화와 조경을 위한 토양을 폐기물을 원료로 하여 생산하기 위해서 폐 콘크리트에 여러 가지 유기성 폐기물을 혼합하였다. 이 혼합물이 식물의 성장토로 사용될 수 있는 지의 여부를 알기 위해서 혼합물의 고형물과 침출수에 함유된 물질을 독일의 폐기물학회에서 규정한 항목에 따라서 분석, 평가하였고, 이 혼합물에 식물실험을 하여 수확량을 측정하였다. 실험의 결과 이 혼합물은 매립지의 재자연화를 위한 최종복토용으로, 경우에 따라서는 공원이나 정원의 조경용으로 사용될 수 있고, 폐 콘크리트 85%, 하수슬러지 10% 그리고 제지슬러지 5%의 혼합물이 가장 효과적이었다.

• 유기물자원화
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• 제12권3호
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• pp.112-118
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• 2004

파쇄, 탈수된 음식물 쓰레기를 양계가 사료로 섭취하고 배설한 계분에 제지슬러지를 혼합하여 21일간 부숙시킨 먹이를 줄지렁이 유충에게 급이하면서 줄지렁이의 생체량, 사망률, 환대발현률, 난포 생산수 및 음식물류 폐기물, 계분, 계분과 제지슬러지 혼합시료의 이화학적 성상을 조사하였다. 먹이 급이 10주후의 줄지렁이 생체량이 초기 생체량에 비해 5.7% 감소하였으며, 환대발현률이 매우 저조하고 산란이 전혀 이루어지지 않아 계분내의 염분이 지렁이의 성적 성숙을 저해하는 것으로 나타났다. 그러나 계분이 줄지렁이의 사망률에는 큰 영향을 미치지 않았다.

• 유기물자원화
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• 제15권4호
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• pp.93-99
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• 2007

제지슬러지를 먹이로 공급하여 줄지렁이를 사육하면서 지렁이 사육상 높이 및 사육상내 개체군 밀도가 높아짐에 따른 줄지렁이 개체군의 수직분포를 사육상 표층으로부터 5 cm 간격으로 조사하였다. 줄지렁이 유충, 성충, 개체군의 50% 이상이 표층으로부터 5 cm 이내에 서식하였으며, 줄지렁이 유충, 성충, 난포 개체군의 96% 이상이 표층으로부터 20 cm 이내에 서식하였다. 사육상의 높이가 50 cm로 높아질 때까지 사육상 높이나 지렁이 개체군 밀도 변화가 지렁이 개체군의 수직분포 비율에 큰 영향을 미치지 않았다.