• 한국생산제조학회지
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• 제22권3_1spc호
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• pp.489-495
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• 2013

This study analyzed thevariation in the cutting force when the cutting area of a terrace volume is machined, which is generally left after the rough cutting of a sculptured surface. The numerically simulated results for the cutting forces are compared with cutting force measurements by considering the theoretical prediction of the cutting area formation and specific cutting volume. The variation in the cutting force is measured using a dynamometer installed on a machining center for 19 different kinds of test pieces, which are selected according to the variation in the terrace volume factor, tool diameter factor, and cutting depth factor. As a result, it is verified that the cutting forces evaluated by the numerical analysis coincide with the measured cutting forces, and it is proposed as a practical cutting force prediction model.

• 한국생산제조학회지
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• 제19권1호
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• pp.114-120
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• 2010

Optimization of the turning process has been concentrated on the selection of the optimal cutting parameters, such as cutting speed, feed rate and depth of cut. However, optimization of the cutting parameters does not necessarily guarantee the maximum profit. For the maximization of the profit, parameters other than cutting parameters have to be taken care of. In this study, 8 price-related parameters were considered to maximize the profit of the product. Regression equations obtained from RSM technique to relate the cutting parameters and maximum cutting volume with a given insert were used. The experiments with four combinations of cutting inserts and material were executed to compare the results that made the profit and cutting volume maximized. The results showed that the cutting parameters for volume and profit maximization were totally different. Contrary to our intuition, global optimization was achieved when the number of inserts change was larger than those for volume maximization. It is attributed to the faster cutting velocity, which decreases processing time and increasing the number of tool used and the total tool changing time.

• 대한공간정보학회지
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• 제17권2호
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• pp.11-17
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• 2009

지상라이다는 대용량 3차원 지형좌표의 획득이 가능하여 이를 활용한 터널계측, 시설물 변위 측정 등 각종 토목공사에서의 적용이 시도되고 있다. 본 실험에서는 토목 공사 공정 중 많은 시간과 자본은 필요로 하는 토공 과정 중 지상 라이다를 이용하여 절토량을 구하는 방법에 대해서 다루었다. 실험방법은 절토지역에 대하여 지상라이다 측량을 실시하고, 현황도, 계획평면도의 3D Cad 데이터와 획득한 라이다 자료를 비교하여 절토현황을 계산하였다. 사용된 라이다가 보유한 해상도별 절토량 계산 값들을 실험을 통해 비교하였다.

• 한국표면공학회지
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• 제43권1호
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• pp.41-45
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• 2010

The effect of $MoS_2$ and graphite content on wear resistance and mechanical properties of Cu/Sn bonded diamond micro blades was comparatively investigated in terms of volume and weight fraction. For the evaluation of endurance and cutting performance, instantaneous electric power consumption and cumulative wear loss during cutting glass work piece at constant velocity were measured with the micro blades of the wide range of lubricant content. The energy consumption of blades for glass cutting decreased with the content of lubricants. Wear amount of blade in volume increased with the amount of lubricant addition. It was found to be relevant to the decrease in flexural strength and hardness with the amount of lubricants. With the same amount of lubricant content in volume fraction $MoS_2$ showed superiority in mechanical properties and cutting performance than graphite while graphite could result in stronger effect on lowering electric consumption during cutting work piece for the same weight percent fraction than $MoS_2$ because of lower density.

• 한국지능시스템학회논문지
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• 제22권3호
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• pp.294-299
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• 2012

본 논문은 단체 급식용 동결 생선을 일정한 중량으로 절단하기 위하여, 생선의 외형 및 부피 예측 모델링 기법을 제안하고, 실제 생선에 대한 절단 실험을 수행한다. 단체 급식용 동결 생선은 동결 하는 시점에서 발생한 생선의 휘어짐과, 머리를 절단하고 내장을 제거할 때에 발생하는 중공이 존재한다. 이외에도 동결의 영향으로 나타나는 표면의 반짝임이나 수분 량에 따른 무게의 차이로 인해 측정 및 추정의 어려움이 크다. 따라서 동결 생선의 외형과 부피를 정확히 추정하기 위해서는 상기의 특성과 문제점들을 반영한 복합적인 추정 알고리즘이 필요하다. 이를 위해, 중공 예측, 신경망을 이용한 꼬리부분 패턴 분류 및 모델링, 그리고 적분 기법 기반의 부피 예측 알고리즘을 각각 제안하고, 삼치, 꽁치, 고등어 3종류의 생선에 대해서 3차원 계측, 부피 예측 및 절단 실험을 수행한다.

• 소성∙가공
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• 제15권9호
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• pp.654-659
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• 2006

In this paper, the real shapes of micro tool deflection were observed. In micro endmilling process, micro tool deflection generates very serious problems in contrast to macro tool deflection. For analyzing the micro tool deflection, the trend of micro tool deflection was observed using real captured images in this paper. To get the real images of micro tool deflection, micro slot cutting processes were executed under cutting volume using micro endmill($Dia.\;200{\mu}m$) and real images of tool deflection were obtained during cutting processing by high-speed camera. Finally, the extent of tool deflection was calculated by the deflection angle according to cutting volume.

• 대한기계학회논문집
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• 제18권1호
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• pp.53-64
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• 1994

Rouge cutting process takes the major portion of machining operation using NC milling machine. Especially, most of the machining time is spent in this process when molds are machined. Therefore, an efficient algorithm for generating the tool path for rough cutting is suggested in this paper. The first step of the procedure is getting the volume to be machined by applying the Boolean operation on the finished model and the workpiece which have been modeling system. Basic principle of determining machining procedure is that a large tool should be used at the portion of the simple shape while a small tool should be used at the complex portion. This principle is realized by representing the volume to be machined by an octree, which is basically a set of hexahedrons, and matching the proper tools with the given octants. When the tools are matched with the octants, the tool path can be derived at the same time.

• 한국산림과학회지
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• 제81권2호
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• pp.146-155
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• 1992

본(本) 연구(硏究)는 임분(林分)의 직경(直徑) 분포(分布) 및 수고(樹高) 분포(分布)에서는 태벌구조(擇伐構造)의 가능성(可能性)을 시사(示唆)하고 있으나 경급별(徑級別) 재적(材積) 분포(分布)에서는 택벌(擇伐)에 이르지 못한 미성숙(未成熟) 구조(構造)를 보여 갱신과정(更新過程)에 있는 것으로 판단(判斷)되는 강원도(江原道) 인제군 기린면 진동리 고재(所在) 천연(天然) 횬효임분(混淆林分)을 대상(對象)으로 이 임분(林分)의 직경(直徑) 및 재적(材積) 생장율(生長率)의 파악(把握)을 통하여 미래(未來) 임분(林分) 구조(構造)의 변화(變化)를 예측(豫測) 함으로서 이 임분(林分)에 대한 택벌작업종(擇伐作業種)의 가능성(可能性)을 점검(點檢)하였다. 매 1년(年) 단위(單位)로 생장율(生長率)을 이용(利用)한 앞으로 30년간(年間)의 임분(林分) 구조(構造)의 예측(豫測)에 의하면 30년후(年後)에 목표직경(目標直徑) 40cm 이상(以上)에서의 본수(本數)와 ha 당(當) 재적(材積), 그리고 매년(每年) 수확(收穫)이 가능(可能)한 대경목(大徑木) 재적(材積)을 충분(充分)히 보유(保有)할 것으로 예측(豫測)되어 택벌목(擇伐木)으로 경영(經營)할 수 있을 것으로 판단(判斷)되었다. 그러나 균형상태(均衡狀態)에 있는 이상적(理想的)인 택벌목(擇伐木)의 대(大), 중(中), 소경목(小徑木)의 경급별(徑級別) 본수(本數) 비율(比率)인 1 : 2 : 7과 재적(材積) 비율(比率)인 5 : 3 : 2를 유지(維持)하지는 못하고 있는데 이는 앞으로 적합(適合)한 조림(造林) 조치(措置)를 통한 조절(調節)이 가능(可能)할 것으로 보인다.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.1145-1151
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• 2022

A hybrid cutting using both plasma and end mill was developed for safe and efficient dismantling of nuclear facilities. In this cutting method, a moving arc plasma heats up the workpiece before milling. Thermally softened part of the workpiece is then removed quickly and deeply with an end mill. For the cutting experiments, a three-axis numerical control (NC) milling machine was combined with a commercialized arc plasma torch and used to cut 25 mm thick stainless steel plates. Experimental results revealed that pre-heating by arc plasmas can improve the cutting volume per unit time higher than 40% by reducing the cutting load and increasing the cuttable depth when using an end mill without cutting fluids. These advantages of a hybrid cutting process are expected to contribute to quick and safe segmentations of metal structures with radioactively contaminated inner surfaces.

• Geomechanics and Engineering
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• 제13권6호
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• pp.977-995
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• 2017

It is well accepted that rock failure mechanism influence the cutting efficiency and determination of optimum cutting parameters. In this paper, an attempt was made to research the factors that affect the failure mechanism based on discrete element method (DEM). The influences of cutting depth, hydrostatic pressure, cutting velocity, back rake angle and joint set on failure mechanism in rock-cutting are researched by PFC2D. The results show that: the ductile failure occurs at shallow cutting depths, the brittle failure occurs as the depth of cut increases beyond a threshold value. The mean cutting forces have a linear related to the cutting depth if the cutting action is dominated by the ductile mode, however, the mean cutting forces are deviate from the linear relationship while the cutting action is dominated by the brittle mode. The failure mechanism changes from brittle mode with larger chips under atmospheric conditions, to ductile mode with crushed chips under hydrostatic conditions. As the cutting velocity increases, a grow number of micro-cracks are initiated around the cutter and the volume of the chipped fragmentation is decreasing correspondingly. The crack initiates and propagates parallel to the free surface with a smaller rake angle, but with the rake angle increases, the direction of crack initiation and propagation is changed to towards the intact rock. The existence of joint set have significant influence on crack initiation and propagation, it makes the crack prone to propagate along the joint.