• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.585-591
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• 1997

The purpose of this experiment is to verify and efficiency of repair for cutting area. The result of this experiment is the fact thar the strength of compression and bending in declined by width and depth of cutting area. Deterioration of strength depends on depth to be repair area the strength of compression decreased up 50% when the repairing area is the fact that it is emerged by the increased of depth size rather than width size.

• 한국초지조사료학회지
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• 제8권3호
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• pp.104-109
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• 1988

A field experiment was conducted in order to investigate the seasonal changes of leaf growth and related characteristics in three cultivars of orchardgrass; Potomac, Kay and Sumas. The results were summarized as follows: 1. Leaf elongation was increased in a nearly linear phase during first and third cutting stages. It was increased slowly in early 10 days to 15 days after cutting and increased rapidly thereafter during the rest cutting stages. In cultivars, Potomac was showed hlgher leaf elongation than other cultivars during all cutting stages. There was no difference of leaf width within cutting stages, but the leaf width of fall regrowth was narrow. Sumas had relatively short and wide leaves. 2. Leaf dry weight and leaf area in first cutting stage were larger than others. Leaf area was increased rapidly from 15 days after cutting and leaf $we$ was increased rapidly from 20 days over all cutting stages. The increase in leaf area and dry weight were slow down after 30 days. 3. Number of epidermal cells was increased rapidly after cutting and the rate of increase was slow down after 30 days. In a cross section of leaf tissue, the part of mesophyll was occupied with about 60% of total area and larger area than other tissues. Leaf tissue had a large vacancy at early growth period after harvest and was filled gradually with mesophyll. This result was related to the increase of leaf dry matter.

• 한국의상디자인학회지
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• 제8권1호
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• pp.69-79
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• 2006

The purpose of this study is to find the proper width of fabric which can bring high efficiency on productivity. We focus on the marking method by comparing and analyzing the marking efficiency of A-line skirt. This study employs 4 criteria to mark the A-line skirt, which are cutting method, angle, width, and direction, respectively. There can be 2 different cutting methods(fold pattern and add seam pattern at the front and back center line), and 2 different angles(warp angle and bias angle). Also, width of the fabric can be classified into 2 groups(110cm, 150cm), and marking direction can be grouped into 2(one direction marker and one direction per each size marker). These 4 criteria make 16($2^*2^*2^*2$) cases for this study. Main findings are follows. First, the skirt with folded at the center line had higher efficiency rate than the skirt with add seam at the center line. Second, the skirt with the 150cm width has higher efficiency rate than that of 110cm. Third, fixing the warp angle has higher efficiency rate than that of fixing the bias angle at the front and back center line. Finally, one direction per each size marker has much higher efficiency than the one direction marker.

• 대한기계학회논문집A
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• 제29권2호
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• pp.333-340
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• 2005

Feedrate is one of the factors that have the significant effects on the productivity, qualify and tool life in the cutting mechanism as well as cutting velocity, depth of cut and width of cut. In this study, in order to realize the high-efficient machining, a new feedrate optimization method is proposed based on the concept that the optimum feedrate can be derived from the allowable cutting power since the cutting power can be predicted from the cutting parameters as feedrate, depth of cut, width of cut, chip thickness, engagement angle, rake angle, specific cutting force and so on. Tool paths are extracted from the original NC program via the reverse post-processing process and converted into the infinitesimal tool paths via the interpolation process. And the novel NC program is reconstructed by optimizing the feedrate of infinitesimal tool paths. Especially, the fast feedrate optimization is realized by using the Boolean operation based on the Goldfeather CSG rendering algorithm, and the simulation results reveal the availability of the proposed optimization method dramatically reducing the cutting time and/or the optimization time. As a result, the proposed optimization method will go far toward improving the productivity and qualify.

• 한국정밀공학회지
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• 제16권9호
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• pp.191-199
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• 1999

In the continuous cutting process such as turning operation, chip control is thought very important to achieve the unmanned manufacturing system. The prediction of chip breakage under the given conditions is a substantial element for chip control. In this paper, a systematic approach to know the chip breaking region is represented under the concept of equivalent parameters. to Verify the suggested model, cutting experiments are executed with a commercial type and two other type chip breakers which have modified chip breaker parameters such as land width, groove width and nose radius. predicted chip breaking regions using the 3D cutting model agrees with those obtained from the experiments.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 춘계학술발표대회 개요집
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• pp.36-38
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• 2002

This paper is a study on the effect of the cutting speed, length of tip-specimen and cutting thickness in CNC gas cutting of the high-tensile steel plate(AH36). Experiments were performed to investigate the variations of cutting surface, surface roughness and kerf width under various cutting conditions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.652-655
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• 2001

In this paper, I have studied minimization of the kerf-width and surface burning which are occurred after the singulation process of multi layer $\mu$-BGA( thickness 1.1 mm, 0.9 mm) with a pulsed Nd:YAG( = 532 nm, repetition rate = 10 Hz) laser. The thermal energy of a pulsed Nd:YAG laser is used to cut the copper layer. I have studied are minimization of the surface burning and kerf-width using a photo resist, $N_2$blowing and polyester double sided tape as a cutting parameter. The $N_2$blowing reduces a laser energy loss by debris and suppresses a surface carbonization. Also, I have studied characters of cutting with a choice of side of laser beam incidence. The SEM(Scanning Electron Microscope), non-contact 3D inspector and high-resolution microscope are used to measure kerf width and surface state. The optimum value of 1.1 mm $\mu$-BGA singulation is 524 $\mu$m that is reduced kerf width of 60 % with $N_2$blowing. And I obtained reduction of carbonization of 68 % with a polyester double side tape in 0.9 mm $\mu$-BGA. I used laser intensity of 1.91$\times$10$^{6}$ / $\textrm{cm}^2$ in this study.

• 한국광학회:학술대회논문집
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• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.37-41
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• 1990

The quality of cutting surface such as surface roughness, heat affected zone, serf width can be improved by controlling the parameters of cuting process. These parameters includes cutting velocity, laser beam power, material depth and assistant gas. Thermodynamic analysis and systematical experiments are attempted to pedict and determine the optimal cutting condition. There exists the optimal cutting condition to ensure high quality surface. Under this operation, the minimum surface roughness of the mild steel, the stainless steel and the titanium becomes 3.8${\mu}{\textrm}{m}$ 13${\mu}{\textrm}{m}$ and 10${\mu}{\textrm}{m}$ respectively.

• 한국가구학회지
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• 제16권1호
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• pp.17-23
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• 2005

European maple is famous for the optimum solid wood for making bridge which is the most important part in violin acoustics. This study was carried out to investigate the variation of main features, i. e. annual ring width and cutting direction of costly imported violin bridge blanks and to examine the effect of these features of the blanks on the vibrational characteristics of bridge blanks. Imported violin bridge blanks had somewhat large variation in major macroscopical and physical properties and there was little relationship between annual ring density and weight of maple blanks. Resonant frequency of violin bridge blanks had some positive correlation with weight, however, damping having negative relationship with frequency was seldom affected by any physical properties of the maple blanks. Deviation from the radial cutting of tail side(ray direction from top toward feet on the edge of bridge blank) lowered the resonant frequency. Consequently, weight and ray direction should be taken for the critical quality decisive factors(QDF) of incoming bridge blanks by not only inspectors also luthiers who tune the bridge by shaping and are responsible for the final timbre quality of this complicate instrument.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.984-987
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• 2002

Abrasive water-jet(AWJ) machining is a new cutting technology. The AWJ can cut various materials such as metal, glass and stone. However, the AWJ machining makes troubles including kerf, rounding and side taper. In this study, we investigated the correlation between parameters of abrasive water-jet machining and cutting characteristics. The machining parameters were the material thickness and the traverse speed. The experiment was conducted to cut the stainless steel(STS41) and the mild steel(SS41) specimens. The results of the experiment were presented as the relation between cutting conditions and troubles of a dimension error, a conner error, an uncut width and a kerf.