• 제목/요약/키워드: New Shape

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고차민감도를 이용한 전기기기 형상 최적화 (Shape Optimization of Electromagnetic Devices using High Order Derivativ)

  • 안영우;곽인구;한송엽;박일한
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.241-243
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    • 1998
  • This paper describes a new method for the faster shape optimization of the electromagnetic devices. In a conventional iterative method of shape design optimization using design sensitivity based on a finite element method, meshes for a new shape of the model are generated and a discretized system equation is solved using the meshes in each iteration. They cause much design time. To save this time, a polynomial approximation of the finite element solution with respect to the geometric design parameters using Taylor expansion is constructed. This approximate state variable expressed explicitly in terms of design parameters is employed in a gradient-based optimization method. The proposed method is applied to the shape design of quadrupole magnet.

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A new piezoelectric shell element and its application in static shape control

  • Chen, Su Huan;Yao, Guo Feng;Lian, Hua Dong
    • Structural Engineering and Mechanics
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    • 제12권5호
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    • pp.491-506
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    • 2001
  • In this paper, a new three-dimensional piezoelectric thin shell element containing an integrated distributed piezoelectric sensor and actuator is proposed. The distributed piezoelectric sensor layer monitors the structural shape deformation due to the direct effect and the distributed actuator layer suppresses the deflection via the converse piezoelectric effect. A finite element formulation is presented for static response of laminated shell with piezoelectric sensors/actuators. An eight-node and forty-DOF shell element is built. The performance of the shell elements is improved by reduced integration technique. The static shape control of structure is derived. The shell element is verified by calculating piezoelectric polymeric PVDF bimorph beam. The results agreed with those obtained by theoretical analysis, Tzou and Tseng (1990) and Hwang and Park (1993) fairly well. At last, the static shape control of a paraboloidal antenna is presented.

발포폴리스티렌 폼을 이용한 단속형 가변적층 쾌속조형공정과 응용기술을 이용한 3차원 기능성 제품 제작에 관한 연구 (Investigation Into the Manufacture of 3D Functional Parts using VLM-ST and Its Applied Technology)

  • 안동규;이상호;최홍석;김기돈;양동열
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.190-194
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    • 2001
  • The integration of rapid prototyping and tooling has the potential for the rapid net shape manufacturing of three-dimensional parts with geometrical complexity. In this study, a new rapid prototyping process, transfer type of Variable Lamination Manufacturing (VLM-ST), was proposed to manufacture net shape of 3-D prototypes. In order to examine the efficiency and applicability of the proposed process, various 3-D parts, such as a world-cup logo, and extruded cross and a knob shape, were fabricated on the apparatus. In addition, the new rapid tooling process, which is a triple reverse process, was proposed to manufacture of 3-D functional part using VLM-ST prototypes and the plastic part of the knob shape was produced by the new rapid tooling process.

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泰國 코사무이와 코파응안의 Burmoniscus屬 陸棲 等脚類(Isopoda, Oniscidea, Philosciidae) 2新種 (Two New Species of the Genus Burmoniscus (Isopoda, Oniscidea, Philosciidae) from Ko Samui and Ko Pha Ngan, Thailand)

  • Jeon, Dae-Soo;Kwon, Do-Heon
    • Animal Systematics, Evolution and Diversity
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    • 제17권1호
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    • pp.145-153
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    • 2001
  • 泰國의 코사무이와 코파응안에서 採集된 Burmoniscus屬 陸棲 等脚類 2新種을 B. siamenis와 B. phanganensis로 命名하고 記載하였다. B. siamenis는 體色과 꼬리마디의 形態가 B. mauritiensis (Taiti and Ferrara, 1983)와 類似하나 제7가슴마디의 뒷모서리가 鈍角을 이루며 수컷의 제2배다리 안다리의 끝이 뭉툭하다는 점 등이 다르다. E. phanganensis는 제7가슴마디와 꼬리마디의 形態가 B. ocellatus (Verhoeff, 1928)와 類似하나 수컷의 제1배다리 안다리에 2줄의 작은 돌기열이 있다는 점이 다르다.

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Ray distance를 이용한 3차원 형상의 유사성 판단 (Similarity Measurement of 3D Shapes Using Ray Distances)

  • 황태진;정지훈;오헌영;이건우
    • 한국정밀공학회지
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    • 제21권1호
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    • pp.159-166
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    • 2004
  • Custom-tailored products are meant by the products having various sizes and shapes to meet the customer's different tastes or needs. Thus fabrication of custom-tailored products inherently involves inefficiency. To minimize this inefficiency, a new paradigm is proposed in this work. In this paradigm, different parts are grouped together according to their sizes and shapes. Then, representative shape of each group is derived and it will be used as the work-piece from which the parts in the group are machined. Once a new product is ordered, the optimal work-piece is selected through making similarity comparisons of new product and each representative shape. Then an effective NC tool-path is generated to machine only the different portions between the work-piece and the ordered product. The efficient machining conditions are also derived from this shape difference. By machining only the different portions between the work-piece and the ordered product, it saves time. Similarity comparison starts with the determination of the closest pose between two shapes in consideration. The closest pose is derived by comparing the ray distances while one shape is virtually rotated with respect to the other. Shape similarity value and overall similarity value calculated from ray distances are used for grouping. A prototype system based on the proposed methodology has been implemented and applied to the grouping and machining of the shoe lasts of various shapes and sizes.

Ray distance를 이용한 3차원 형상의 유사성 판단 (Similarity Measurement of 3D Shapes Using Ray Distances)

  • 정지훈;황태진;오헌영;이건우
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.70-73
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    • 2003
  • Custom-tailored products are meant by the products having various sizes and shapes to meet the customer's different tastes or needs. Thus fabrication of custom-tailored products inherently involves inefficiency. To minimize this inefficiency, a new paradigm is proposed in this work. In this paradigm. different paris are grouped together according to their sizes and shapes. Then, representative shape of each group is derived and it will be used as the work-piece from which the parts in the group are machined. Once a new product is ordered, the optimal work-piece is selected through making similarity comparisons of new product and each representative shape. Then an effective NC tool-path is generated to machine only the different portions between the work-piece and the ordered product. The efficient machining conditions are also derived from this shape difference. By machining only the different portions between the work-piece and the ordered product, it saves time. Similarity comparison starts with the determination of the closest pose between two shapes in consideration. The closest pose is derived by comparing the ray distances while one shape is virtually rotated with respect to the other. Shape similarity value and overall similarity value calculated from ray distances are used for grouping. A prototype system based on the proposed methodology has been implemented and applied to the grouping and machining of the shoe lasts of various shapes and sizes.

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유방 확대수술 환자용 압박의류 개발 (Development of Compression Garments for Breast Augmentation Patients)

  • 이경화;최현옥
    • 한국의류학회지
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    • 제44권1호
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    • pp.1-12
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    • 2020
  • It is essential to apply compression bands or pressure garments that can stabilize the breast implants and breast shape as well as help shape the breast to the desired shape immediately after breast augmentation surgery. It is necessary to study the compression garment which is able to properly cover a deformed breast due to the operation and shape it as a beautiful breast. The subjects of the study were 6 women who experienced breast augmentation surgery with an under bust size of 70 or 75, cup size of C cup with a hemispherical and conical shape. We analyzed the dissatisfaction and satisfaction factors through the evaluation of the 4 types of commercial compression garments and developed the new functional post-operative bra which can be worn immediately after the operation according to the breast characteristics of breast augmentation patients. We have developed new bra patterns; a front opening type garment with wings and a band type garment both sides that allow the band to be pressed from the front center. The comparative wearing evaluation indicated that the superiority of the new compression garments also provided a higher the satisfaction of the newly developed bra (front adjustable style) than a commercial band.

A Feasibility Study on the Flow Passage Shape for an Inline Francis Hydro Turbine

  • Chen, Chengcheng;Singh, Patrick Mark;Inagaki, Morihito;Choi, Young-Do
    • 한국유체기계학회 논문집
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    • 제18권2호
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    • pp.5-13
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    • 2015
  • The aim of this study is to investigate the feasibility of a new type of casing for the inline Francis hydro turbine. Comparing with the traditional turbine with spiral casing, this turbine is unique for its flow passage shape at the first stage of flow to the turbine, very similar to a pipe, called inline casing. Before the commercialization of this new type of casing, a global investigation of the inline casing must be conducted. Preserving the structural characteristics of simple, compact-size and convenient for manufacture, different shapes of the belt passage, vertical corner and stay vanes are applied to investigate the influence of flow passage shape on the turbine performance. Stable and relatively high efficiency is achieved regardless of flow passage shape difference proving the feasibility of the inline casing used in a hydro turbine.

Eight New Species of Genus Coscinoderma (Demospongiae: Dictyoceratida: Spongiidae) from Chuuk Island, The Federated States of Micronesia

  • Sim, Chung Ja;Kim, Young A
    • Animal Systematics, Evolution and Diversity
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    • 제30권4호
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    • pp.248-259
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    • 2014
  • This paper describes eight new species of the genus Coscinoderma from Chuuk Island, the Federated States of Micronesia. This genus is characterized by very fine, meandering uncored secondary fibres. All the new Coscinoderma species are compared with eight other valid species from tropical regions. Coscinoderma folium n. sp. is characterized by its large thickly foliate shape, and cored primary fibres are easily found between secondary fibres in choanosome. Coscinoderma lacium n. sp. differs in having round conules and no cored primary fibres. Coscinoderma cavernosa n. sp. is distinguished from other species by its cavernous shape and long sharp conules. Coscinoderma wenoa n. sp. is characterized by long conules and primary fibres. Coscinoderma mappula n. sp. differs in having a thick sand crust in the choanosome. Coscinoderma bakusi n. sp. is characterized by having several oscules at the top of the sponge and color changed grey to dark brown in alcohol. Coscinoderma pollax n. sp. is characterized by having a small thumb shape. Coscinoderma truki n. sp. similar to C. pollax in shape but differs in cored primary fibres with many spicules.

CSR적용 극비대선의 저항성능 개선에 관한 연구 (Study on the Resistance Improvement for an Extremely Full Ship Under CSR)

  • 박현석;김태훈;오세형;김병남;김우전;유재훈;조성훈
    • 대한조선학회논문집
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    • 제48권2호
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    • pp.99-106
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    • 2011
  • The appearance of CSR changes the concept of the hull form design as well as structural design, since the application of CSR inevitably brings the lightweight increase of a ship. Keeping the original design constraints such as principal particulars, deadweight, and speed performance, designers have to increase the volume of the hull form. As a result, the entrance angle at bow end should become larger, which results in blunter waterline shape. For a slow and full ship having high $C_B$ more than 0.85, a new concept of bow shape has been required to alleviate the increase of wave-making resistance, since it is very difficult to improve waterline and frameline shape for such a full ship. In this paper a new bow shape of Capesize Bulk Carrier was developed to improve its wave-making characteristics without incompliance with the design constraints. For loading manual calculation, NAPA software was used. FLUENT6.3.26 and WAVIS1.4 were used to evaluate resistance performance of the subject hull forms. The newly designed hull form was tested at SSPA model basin for the final confirmation of resistance and propulsion performance of the ship. It was found that the new bow shape of a Capesize Bulk Carrier improved the resistance characteristics greatly compared to a conventional bulbous bow. The other benefits of new bow shape on the manufacturability were also investigated.