• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.101-102
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• 2002

Indicial response characteristics of a rotor supported by a gas-lubricated, spiral-grooved proceeding bearing are studied theoretically to develop a fundamental investigation for the bearing design with considering NRRO characteristics. The trajectory of rotor movement is calculated by applying the non-linear orbit scheme against a prescribed impulse load, then two characteristic quantities are introduced to evaluate the indicial response performance of the bearing, i.e., 'maximum deviation of rotor center' and 'integrated rotor center deviation'. The effects of some design parameters of spiral grooves to these representative quantities are studied so that 'robust' design against impulse load is discussed.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.182-188
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• 2008

Automated parking systems, which automatically park and retrieve vehicles, have been steadily replacing conventional parking systems. The spiral parking system is a type of automated parking systems that has cylindrical parking tower. We develop an economic design model of spiral parking system based on a recursive optimization and simulation procedure in which the dynamic nature of the parking system can be integrated into the mathematical programming model. The optimal values of design parameters are found that gives the minimum total cost while complying with the desired performance of the system.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.363-368
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• 2000

The Korean Bridge Design Standard Specifications adopted the seismic design requirements in 1992. However, The current seismic design requirements for bridges are based on the USA seismic codes for sever earthquake. This provides the basic factors that affects the performance of spiral reinforced concrete piers for seismic loading, and The specimen tests are performed based on load-displacement, effective stiffness and displacement ductility, etc. The quasi-static test was adopted in order to investigate seismic performance of the spiral reinforced concrete pier specimens which had different transverse steel amount, spacing and longitudinal steel ratio under different axial load levels. This study is concluded that seismic design for transverse reinforcement content of spiral reinforced concrete column has influenced on axial load and effective stiffness etc.

• 한국산업융합학회 논문집
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• 제10권3호
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• pp.171-177
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• 2007

It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

• 한국가시화정보학회지
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• 제10권1호
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• pp.27-33
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• 2012

This paper describes a new design of small-scale horizontal wind blade, called spiral wind turbine blade. Theoretical and numerical approaches on the prediction of aerodynamic performance of the blade have been conducted. A theoretical equation is successfully derived using the angular momentum equation to predict aerodynamic characteristics according to the design shape parameters of spiral blade. To be compared with the theoretical value, a numerical simulation using ANSYS CFX v12.1 is performed on the same design with the theoretical one. Large scale tip vortex is captured and graphically presented in this paper. The TSR-$C_p$ diagram shows a typical parabolic relation in which the maximum efficiency of the blade approximately 25% exists at TSR=2.5. The numerical simulation agrees well with that of the theoretical result except at the low rotational speed region of 0~20 rad/s.

• 한국전기전자재료학회논문지
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• 제18권3호
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• pp.216-218
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• 2005

Planar spiral inductors on silicon substrates were optimally designed using MATLAB, which is a tool to perform numerical computations with matrices. The equivalent circuit parameters of the spiral inductors were extracted from the data measured from the spiral inductors fabricated using a 0.18 $\mu\textrm{m}$ RF CMOS process. The metal width, which is a critical design parameter, was optimized for the maximum quality factor with respect to the operating frequency.

• 한국전자파학회논문지
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• 제20권2호
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• pp.208-214
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• 2009

UWB USPR 시스템 응용 초광대역 마이크로스트립-CPS(Coplanar Stripline) 발룬을 이용한 self-complementary 스파이럴 안테나의 설계와 실험적 결과를 제시하였다. 초광대역 특성을 갖는 평면형 마이크로스트립-CPS 발룬을 적용하여 스파이럴 안테나 고유의 초광대역 특성을 유지하게 하였고, 각각 설계된 안테나와 발룬을 임피던스 정합의 방법을 이용하여 연결함으로 간단한 안테나 설계 과정을 보였다. 설계된 스파이럴 안테나는 등각 형태의 self-complementary 스파이럴 안테나이다. 제작된 안테나는 2.9 GHz에서 12 GHz의 넓은 주파수 특성을 가지며, 2.7에서 5.3 dB의 비교적 평탄한 이득과 $70^{\circ}$ 이상의 빔 폭을 가졌다. 이 결과를 통해 초광대역 마이크로스트립-CPS 발룬의 스파이럴 안테나의 적용 가능성을 검증하였다.

• Journal of electromagnetic engineering and science
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• 제13권3호
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• pp.165-172
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• 2013

This paper describes a design for a spiral antenna with a conical wall to obtain the high gain. The gain and the axial ratio of the spiral antenna were improved by a new design that included a conical wall and an optimized Archimedean slit on the ground plane in a conventional antenna with a circular cavity wall and a 4.5-turn slit. A gain improvement of 9.5 dBi higher and a good axial ratio of 1.9 dB lower were measured by the added conical wall and the newly designed slit from the current distribution control on the ground plane, respectively. The measured return loss, gain and axial ratio of the proposed antenna showed a good agreement with the simulated results. The proposed antenna will be applied to a non-linear junction detector system.

• 한국산학기술학회논문지
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• 제10권10호
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• pp.2639-2645
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• 2009

본 논문은 나선형 공진기를 이용한 CPW 발진기의 설계에 대하여 기술한다. CPW 나선형 공진기는 기존의 CPW 헤어핀, 헬리컬 공진기에 비하여 높은 Q 특성을 가지므로 출력특성과 크기가 개선된 발진기 설계에 유리하다. CPW 발진기 설계에 앞서 세 가지 CPW 공진기의 특성을 비교한다. EM 시뮬레이션을 행하여 공진기 설계 및 발진기 성능 확인에서의 정확도를 높였음을 보인다. 세 가지 CPW 공진기를 이용하여, 5.7 GHz 대역에서 각각 발진기를 설계하였다. 제작 및 측정 결과, 헬리컬, 헤어핀, 나선형 공진기를 이용한 각각 CPW 발진기의 측정된 출력은 각각 2.55 dBm, 2.64 dBm, 4.98 dBm이다. 한편 세 가지 공진기는 각각 $102.15mm^2,\;130.05mm^2,\;80.625mm^2$ 크기를 보여, 제안한 CPW 나선형 공진기가 다른 공진기에 비해 크기 감소 효과도 우수함이 제시된다.

• 한국전자파학회논문지
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• 제24권1호
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• pp.36-46
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• 2013

본 논문은 휴대형 비선형 소자 탐지기용 광대역 스파이럴 안테나의 설계를 제안한 것이다. 광대역 안테나의 설계를 위해 방사면 위의 스파이럴 턴 수를 최적화하는 반복 계산이 고려되었다. 원형 편파 설계를 위해 접지면과 방사면 사이의 동일 전류 분포를 유지하기 위해 Archimedean 스파이럴 슬릿을 가진 접지면이 고려되었다. 또한, 고 이득과 고 지향성을 실현하기 위해 캐비티 벽과 금속 캡을 접지면 뒤에 고려하였다. 반사 손실의 측정결과는 관심 대역인 2.4~2.44 GHz, 4.84~4.92 GHz, 7.28~7.36 GHz에서 VSWR 2:1과 잘 일치하였다. 측정된 축비 값은 3 dB 이하로 관측되었고, 모의 실험 결과와도 잘 일치하였다. 관심 대역에서 6.8 dBi 이상의 측정된 이득을 가지는 우수 원형 편파 특성이 관측되었다.