• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.1063-1067
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• 1997

A study of carbide step drill cutting ability is highly progessing the step drill with more then twice diameter rate is so difficult in regrinding and very easy to damage during machining. As the machining of step drill for closed hole is occur to breakage at small diamter poistion, so it is very difficult to machinine. Thue, in this experiment, We investance roundness and surface roghness by machining distance and were identifid that the first distance, 5~10m, was fine with 7 .mu.m but the arround of 15m was happened so much alternation. And we were indentified that after 20m was happend statable machining. The surface roughness was happened the same conditions. So application of stwp drill we think that the selection of cutting conditions need lots consideration and the study of step drill's diameter ratio ratio is carred out.

• 동아시아식생활학회지
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• 제2권1호
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• pp.83-94
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• 1992

As the result of the research on the manufacturing procedure of Sogog-ju in the classical literature(35 kinds), it was found that Sogog-ju is usually brewed on the first Boar day of January and Sogog-ju base is added to it in about 7days and then the fermentation of Sogog-ju comes to end in about 21 days. The material grains out of 48 items, used in the first step of brewing Sogog-ju, are nonglutnous rice 47 items(98%), flour 20items(42%), somnuruk 9 items(19%) out of nuruk (fermenter) 48 items (100%) and nuruk water 5 items(17%), and flour 3 items(6%) are used, but fermenter nuruk is not used. When the grains are used in the first step of brewing, they are usually in the form of gruel and rice cake, and in the second step of brewing, they are usually made into steam water soaked rice. Nuruk, Which is largely used in the first step, is usually put after the processed grains get cold, but in the second step of brewing, it may be put into the still warm grains. There are hardly any cases when nuruk is used in conspicously small quantity.

• 대한전자공학회논문지
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• 제25권6호
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• pp.663-671
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• 1988

In this paper, in order to reduce the blocking effect of block coded images, we propose the method considering the lowpass and bandpass components of Granrath's human visual model. This method consists of two-stage enhancement procedure. The first step is lowpass filtering which smooths out the blocking effect, and the second step is a high frequency enhancement procedure to increase the contrast decreased by the lowpass filtering in the first step. In the first step, the one-dimensional Gaussian filter which aligthns parallel to the edge direction is considered to preserve the edge in the block and the two-dimensional Gaussian filter is used to smooth out the blocking effect near the block boundaries. In the second step, the lowpass and bandpass components of the Granrath's model are considered to increase contrast in a restored image. The performance comparison of the proposed method and the existing mehtods is made by a computer simulation with several block coded images. We can see that the enhancement in the subjective quality of images of the proposed method is more significant than the enhancement in the subjective quality of images of the proposed method is more significant than the existing methods, though the proposed method does not show better performance on the PSNR gain, the poor measure of picture quality for block coded images.

• 방사선산업학회지
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• 제9권2호
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• pp.91-102
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• 2015

The iridium disc, generally used in industrial radiography, is examined to find the fracture morphology and fine particles remaining on the shear blank surface. Randomly selected 1,200 discs were observed under a scanning electron microscope tilted more than $45^{\circ}$. Fracture surfaces are classified into three groups: (1) surface fall-out, (2) fracture on the edge and (3) multi-step brittle fracture, which shows the mutual relationship between the fracture morphology and remaining particles. Fracture particles were removed by cleaning the discs in a ultrasonic bath with acetone and collected at the bottom. Removed number of the particles were counted for each different group of fracture surfaces. Followings are conclusions: (1) About 80.5% of discs (966/1,200), have sound plastic shear surfaces with particles remained. (2) About 2% discs accompany surface fall-out's having large particles tens of ${\mu}m$, which is stable not to be pulled out even after the considerably long time of ultrasonic cleaning. (3) About 5% discs contain the fractures on the edge and the particles are removed thoroughly within 30 minutes. (4) 234 discs out of 1,200 discs have multi-step fracture surfaces whose particles never removed in a short period of time but come out very slowly. Such a disc having multiple-step fracture is attributed to the promate cause to the 'leaker'. It is noted here that the discs having mutiple-step fractures should be treated separately with special care, and it is need to study how to treat them.

• Smart Structures and Systems
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• 제30권2호
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• pp.173-181
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• 2022

The current paper presents a technique to detect crack in non-uniform cantilever-type pipe beams, that have step changes in the properties of their cross sections, restrained by a translational and rotational spring with a tip mass at the free end. An equation for estimating the natural frequencies for the non-uniform beams is derived using the boundary and continuity conditions, and an equivalent bending stiffness for cracked beam is applied to calculate the natural frequencies of the cracked beam. An experimental study for a step-changed non-uniform cantilever-type pipe beam restrained by bolts with a tip mass is carried out to verify the proposed method. The translational and rotational spring constants are updated using the neural network technique to the results of the experiment for intact case in order to establish a baseline model for the subsequent crack detection. Then, several numerical simulations for the specimen are carried out using the derived equation for estimating the natural frequencies of the cracked beam to construct a set of training patterns of a neural network. The crack locations and sizes are identified using the trained neural network for the 5 damage cases. It is found that the crack locations and sizes are reasonably well estimated from a practical point of view. And it is considered that the usefulness of the proposed method for structural health monitoring of the step-changed non-uniform cantilever-type pipe beam-like structures elastically restrained in the ground and have a tip mass at the free end could be verified.

• 한국CDE학회논문집
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• 제7권3호
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• pp.170-176
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• 2002

To exchange CAD data between heterogeneous CAD systems, we generally use a neutral format especially STEP, which is the international standard (ISO-10303) for product model data exchange. AP214 (Application Protocol) for the automotive industry not only takes into account geometry and organizational data, but also provides a classification mechanism for product modeling. When reading a STEP file during a design process that is exported from other CAD systems, it is a burden to a designer to go through the tedious process of removing duplicate or non-manifold entities, adjusting parts, and rearranging text. We analyze the structure of AP214 and develop a healing tool to solve the following problem. Without the assembly information in the Master workspace of CATIA, or to read a STEP file from Pro/Engineer, a designer should do a repetitive process of disintegrating an assembly into parts one by one. We have developed a post-processing tool for STEP AP214 that separates out a part from an assembly model and adjusts superfluous or useless entities using the ACIS kernel.

• 정보관리연구
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• 제28권1호
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• pp.34-61
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• 1997

본고에서는 국내 대학도서관과 국외 프로젝트 등 전자문헌제공의 현황분석을 기반으로, 대학도서관이 수행해야 할 전자문헌제공의 단계별 모형을 제시하고자 한다. 모형의 단계는 이용자의 신청단계, 전자문헌 구축단계, 전자문헌 전송단계로 구성되며, 대학도서관은 전자문헌제공을 각 단계별로 실시하여 최신 정보를 요구하는 이용자의 정보 욕구를 충족시킬 수 있다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.191-195
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• 2009

A parametric study for for the water entry of a two dimensional symmetric wedge with deadrise angle of 10 degrees was carried out to find out the most dominant parameter. Water entry problem with constant velocity is simplified as the stationary wedge in the way of the upcoming water surface. The calculated impact loads showed that the effect of the viscosity was not so important in this problem. For a given grid system a suitable time step size can be found. The most sensitive parameter was found to be the grid size.

• Journal of Biosystems Engineering
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• 제17권3호
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• pp.285-289
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• 1992

Red pepper is composed of pericarp and calyx. Calyx must be removed for the producton of high quality powdered red pepper. However, an apparatus to effectively remove calyx is not available. This study was performed to develop a method to remove calyx. According to the result of this study, the following method was found out to be very effective. Step 1 : Red pepper must be compressed by a compressing apparatus such as roller system. Step 2 : Calyx in red pepper must be plucked out when red pepper passes through roller system with relative velocity.

• 한국콘텐츠학회논문지
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• 제21권11호
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• pp.403-413
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• 2021

본 논문은 영시를 통한 대학 교양 영어 교육의 필요성과, 구체적인 교육 방안을 모색하고, 로버트 프로스트의 「꺼져라, 꺼져라-」를 중심으로 구체적인 교수법 모델을 제공한다. 영시는 학습자 중심의 영어 교육이 중시되고, 읽기, 말하기, 듣기, 쓰기 4영역의 통합 학습 과정이 중시되며, 전공 공부와 취업으로의 연계를 목표로 하는 대학 교양 영어 수업에서 중요한 텍스트가 될 수 있다. 영시의 시각적 이미지, 리듬, 라임, 반복 등의 시적 기교는 언어에 대한 암기 학습 능력 향상과 음성, 구어적 능력 향상과 밀접한 관계가 있기 때문이다. 또한 본 연구에서는 수능 영어에 익숙한 국내 대학교 1학년 학생들에게 가장 적절한 시 선정 기준을 제시하고, 읽기 전 활동, 읽기 활동, 읽기 후 활동으로 나누어 교수법을 제시한다. 그리고 이러한 교수법이 3시간 수업의 대학 교양 영어 수업에서 어떻게 구체적으로 적용될 수 있는지 프로스트의 「꺼져라, 꺼져라-」를 중심으로 제시한다. 그리고 이러한 '탈 활자적' 텍스트를 통한 영어 학습이 학습자 중심의 지속 가능한 학습 모델이 될 수 있다는 점을 밝히고자 한다.