이 연구는 18세기 유럽지도에서 동해가 한국해로 표기되는 데 결정적인 기여를 한 프랑스 지도학자 기욤 드릴의 생애와 업적에 대해 고찰한 것이다. 이를 위해 먼저 드릴이 루이 15세에게 가르친 지리학 내용과 장 밥티스트 놀린과 벌인 지도 표절소송을 통해 지도 표절 방지 규정이 제정된 과정을 살펴보았다. 또한 드릴은 과학적 지도학의 선구자로 지도의 정확성을 추구하기 위한 논문과 지리학 서적을 집필했는데, 이 내용을 통해서 당시의 지리학의 흐름을 파악할 수 있었다. 그리고 그의 등편각선 지도를 소개했으며, 그가 동해를 한국해로 단독 표기한 근원을 안트안느 토마스 지도와의 비교를 통해 확인할 수 있었다.

Prepreg is an abbreviation of Preimpregnated Materials. It is a sheet-type product in which a matrix is ​​impregnated with reinforced fiber. The prepreg has very different properties depending on the orientation of the fibers and the weaving method, and the orientation of the fibers plays an important role in determining the mechanical strength of CFRP. Short and randomly oriented reinforcing fibers show isotropy, while long, unidirectional reinforcing fibers exhibit anisotropic behavior and are strongest when the applied load is parallel to the reinforcing fibers. Classification by the direction of the fiber is divided into unidirectional, orthogonal, multiaxial, and the like. Uni-directional refers to a state in which almost all fibers in the fabric are aligned in one direction. When the fibers used as reinforcing materials are aligned in one direction, the fibers are used in a straight line without twisting during the fabric production process, and there is an advantage in that the amount of fibers used as a whole can be minimized. A uni-directional prepreg exhibits different cutting forces depending on the stacking orientation angle. In this experiment, the optimal cutting conditions for a uni-directional prepreg 45 degree orientation angle specimen are presented.

본 논문은 네일 케어 시에 이미 지각된 불안감과 효용성이 최종 만족도에 어떤 영향을 미치는 지에 대해 분석하는 것을 목적으로 한다. 연구의 목적을 달성하기 위해 네일케어 유형 중 드릴케어와 니퍼케어를 모두 받아본 적이 있는 고객을 모집단으로 설정하여 최종 160부를 유효 표본으로 하여 통계 분석 하였다. 설문 응답은 2023년 04월 10일~05월 10일 까지 오프라인 점포 방문 고객 및 구글 온라인 설문지 배포를 통해 네일케어 인지 및 경험 여부, 인식 및 만족도 및 인구통계적 문항을 조사하였다. 변수별 구성 차원의 타당성을 확 인하기 위해, Varimax-직교회전 방식의 요인분석을 실시하였다. 통계는 WIN SPSS 25.0를 사용하였다. 변수 간의 영향 관계 검증은 회귀분석을 실시하였다. 연구 결과로 드릴케어가 니퍼케어보다 고객 인식에서 불안함이 더 큰 관리방식이지만, 그만큼 지각하는 효용성이 크며 결과적으로 만족도가 더 높은 시술임을 확인하였다. 본 연구는 이러한 결과를 바탕으 로 향후 네일 업계 실무 종사자들의 전문성을 높이고 고객의 신뢰도를 높이고자 하는 시사점을 제언하였다.

One of the most important problems in the cutting process of CFRP is tool wear. During CFRP machining, high temperature caused by friction between the cutting tool and the carbon fiber structure increase tool edge wear. Since CFRP is manufactured in a form in which the fibrous tissue is combined with a bonding resin, delamination caused by the separation of the resin and carbon fiber during process is recognized as a very big problem. This delamination proceeds very rapidly as the wear of the drill edge increases. Therefore, in this experiment, tool wear was measured during drilling using a TiAlN-coating drill with excellent wear resistance. In this study, tool wear is measured to suggest optimized cutting conditions for each material.

Demand for CFRP with new characteristics is increasing in various industrial fields, from parts materials to daily necessities, and research on this is also being actively conducted. CFRP is a material that realizes properties suitable for multiple functions that cannot be seen in a single material by physically combining two or more materials with different shapes and chemical compositions. When machining CFRP using a high-speed steel (HSS) drill or a TiAlN-coating drill with different rotation speed and feed speed, the cutting force was experimentally analyzed and the optimal tool material and cutting conditions were selected. The cutting force according to the change in rotation speed of the high-speed steel drill and the TiAlN-coating drill is compared.

The Carbon Fiber Reinforced Plastic(CFRP) is used in many industrial areas owing to its excellent specific strength. In order to be utilized for machine parts, it is needed to have the hole drilling machining that presents the excellent surface. For the excellent hole machining of CFRP, this study evaluated the cutting force and remaining burr in accordance with changes in temperature by cooling down the temperature of the machining part. It could be used for other machining of composite materials produced by laminating fabric.

Cutting tools tend to wear gradually with progressing of machining process due to extremely high surface loads and temperature from the relative motions between tool and workpiece. Especially, the high cutting temperature is a dominant factor in the relation to tool life. High-pressure coolant has been reported as an effective method to prevent the severe wear from cutting temperature. This research investigates efficient supplying conditions of high-pressure coolant with the CFD results from a internal-flush drilling process. The flow rate of coolant is increased drastically up to three times under 70 bar compared to conventional way.

Carbon fiber reinforced plastics are typical examples of carbon fiber, which retain high strength and high strength at high temperatures. Also, it is applied to various fields, such as the structure of the aircraft, automobile, and the core industries. CFRP machining methods include machining tools such as cutting machining and laser machining. In this thesis, a tool dynamometer and tool microscope were used to measure the cutting characteristics of various cutting conditions and tool wear and tool wear. As a result, the cutting force of the new shape drill (lower shape drill) was measured higher than other tools, the amount of tool wear was the lowest, and it was found that a good machined surface was obtained.

In this study, i machined micro hole to PCB(Printed circuit board) with ultra precision spindle system for mechanical micro drilling. For this i utilized 0.4∼0.6 ㎜ micro drill and observed cutting edge and hole. Results are as follows; in case of drilling with 0.4∼0.6 ㎜ micro drill, micro hole was made specific range of diameter up to 300 times drilling and micro drilled diameter was bigger than micro drill’s diameter at 300 times over. Error ratio of drilled diameter and damaged hole diameter was within 5 % and 17 %. I observed 0.4 ㎜and 0.6 ㎜micro drill’s cutting edge after 500 times drilling and confirm cutting edge width variation and damage, same result found 1000 times drilling with 0.5 ㎜ micro drill.

본 연구는 드릴을 이용하여 화분 공급이 용이한 위치에 수 분용 품종을 편리하게 접목시키는 적기 구명을 목적으로 접목 된 수분용 품종들의 생육특성을 검토하여 동해에 강하고, 다량의 화분을 공급하는 수분용 품종 선발로 이어지는 일련의 연 구를 통해 반영구 안전착과 기술을 확립하기 위해 수행하였다. 1. 드릴을 이용한 접목 유합율은 3월 13일에 40.0 ~ 44.5% 로 가장 높았고, 접목시기가 늦어짐에 따라 감소하였으며, 품 종에 따른 접목 유합율의 차이는 없었다. 2. 가지의 길이는 3월 13일 접목에서 길었고, 품종간에는 수미와 이즈미백도가 짧았다. 화아 수도 3월 13일 접목에서 많 았고, 품종간에는 수미와 이즈미백도가 적었다. 3. 엽 중 질산태질소 함량은 수미와 이즈미백도가 낮았고, 기타 품종은 비슷하였다. SPAD 값과 엽 중 질산태질소 함량 은 비슷한 경향으로 수미와 이즈미백도가 낮았고, 기타 품종 들은 차이가 없었다. 4. 가지 전분 함량은 월동 전에는 이즈미백도가 가장 적었 고, 기타 품종은 비슷하였다. 월동 후에는 장택백봉과 진미가 높았고, 기타 품종은 차이가 없었다. 월동 후와 월동 전의 가 지 전분함량의 비율은 유명과 천홍이 낮았고, 기타 품종은 비 슷한 경향이었다. 5. 접목된 수분용 품종의 화아 동해 비율은 수미와 진미가 21.7 ~ 23.1%로 높았고, 유명과 천홍은 9.4 ~ 12.5%로 낮았으 며, 기타 품종은 17.6 ~ 19.4%였다. 수술 당 화아 수는 유명과 진미가 많았고, 이즈미백도가 가장 적었다. 이상의 결과를 종 합하면 접목 후 생장은 중간 정도이지만 동해에 강하고, 화아 수가 많은 유명이 최근 월동 중 이상저온에 적합한 수분용 품 종으로 유망하였다.

The CFRP composite has a lot of merits such as mechanical characteristic, light and thermal resistance. For these merits, CFRP is applied to so many industrial area. In order to use the composite materials in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joints must be provided, which require precise ,machining. In this study, the specimens differentiating the stacking sequence of 5kinds were used. When drilling the carbon fiber reinforced plastics, it was checked on whether the stacking sequence reached any effect on the cutting force. Also relationship between the drill diameter is examined from the drilling experiment, which is the drilling of Fabric, Unidirectional specimen with ∅6mm, ∅10mm, ∅12mm cemented carbide drill. Considering cutting force and drilling diameter, the results are analyzed.

The experimental data from the central composite design runs were utilized for mathematical models far the drilling characteristics containing linear, quadratic and interactive effects of the parameters such as volume fraction of TiC in the composites, drill speed, feed rate and drill diameter. The models were developed via stepwise selection where the insignificant effects were removed using t-test. The models were subjected to optimization of maximizing drill life and satisfying the other constraints.

Recently micro deep hole drilling is required in the whole industry. However, micro deep hole drilling has still much difficulty because of the lack of drill rigidity and the interruption of chip. We treated a micro deep hole(diameter 0.35mm, depth 3mm) used in a connector jack pin. Therefore, a surface roughness is very important. In this paper, we studied on the variation of the surface roughness for cutting conditions during micro deep hole drilling of Be-Cu material. Most of all, we tried to drill on CNC for the realization of automatization.