• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
• /
• pp.61-61
• /
• 2009

• 전기의세계
• /
• 제14권1호
• /
• pp.5-12
• /
• 1965

In the designs of the sensitive electronic devices such as phase sensitive detector, X-ray diffractometer, and neutron diffractometers, we must take into account the geometrical factors in a coil systems and extraneous stray fields. Input wave forms in such a sensitive electronic devices are often altered by the influence of these factors. Since the magnitude of the stray fields is generally very small, this affection may be removed by applying a good shielding but it is not ease to remove the affection from a geometrical factor. This affection must be however calculated by the theoretical methods and analytical solution in the equation of these factors. The fundamental purpose of this paper lie in the theoretical calculations and practical measurements of the geometrical factor in the coil systems, finite solenoid, and four point prove. In the heoretical calculations, the geometrical factors in the coil systems were calculated by applying the elliptic functions and in the contact points were calculated by applying the elliptic functions and in the contact points were calculated by applying the eigen functions and the infinite series. The measurements were carried out by using the sensitive electronic device made from author's design, as shown in the Fig. 9. The result of this work has verified the essential correctness of theoretical investigations and measuring techniques of geometrical factors on the design of sensitive electronic devices. It also has several advantages such that: (1) all the data obtained may give effective data to designer to work on the field of sensitive electronic devices or microelectronic devices, (2) it has evidently explained the characteristics of electrical investigations and physical definition, and has removed the conventional error of geometrical factors in the coil systems and contact points.

• Environmental Analysis Health and Toxicology
• /
• 제14권3호
• /
• pp.103-111
• /
• 1999

To effectively predict the lipophilicity, the aryl hydrocarbon receptor (AhR) affinity, and TEF (Toxic equivalency factor) of dioxins by geometrical descriptors, the multiple linear regression methods with the forward selection and backward elimination were employed with statistical validity. The lipophilicity, the Ah receptor binding affinity, and the toxic equivalency factor of dioxins could be predicted using some geometrical descriptors.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2012년 춘계학술대회
• /
• pp.277-292
• /
• 2012

The research presents an application of Balanced ANOVA (BANOVA) by utilizing randomized orders for various Split-Plot Designs (SPDs) which include two cell designs, split-plot with one-way HTC (Hard to Control) factor, split-plot with two-way HTC factor, split-split-plot design and nested design. In addition, four MINITAB examples of 2-level split-plot designs based on the number of blocks and the type of whole-plots are presented for practitioners to obtain comprehensive understanding. Furthermore, the geometrical interrelated properties among three typical Designs of Experiments (DOE), such as Factorial Design (FD), Response Surface Design (RSD), and Mixture Design (MD) are discussed in this paper.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2006년도 하계학술발표대회 논문집
• /
• pp.1113-1118
• /
• 2006

A numerical investigation of single phase heat and flow characteristics in circular tubes with a single set of spiral micro fins was performed with varying geometrical parameters like fin height, spiral angle, and number of fins. The properties of $40^{\circ}C$ water was used as a working fluid to simulate a condenser and the RNG $k-{\epsilon}$ turbulence model was adopted. Calculation results were obtained in fully developed turbulent flow with constant surface heat flux boundary condition. Relative terms were introduced to investigate the substitution effect of conventional smooth tubes. The dimensionless terms were the heat transfer enhancement factor, the pressure drop penalty factor, and the efficiency index. Additionally, a numerical optimization was carried out to maximize thermal performance with the concept of the robust design. A statistical analysis showed that fin height interacts with number of fins and spiral angle.

• Progress in Superconductivity
• /
• 제13권2호
• /
• pp.97-104
• /
• 2011

유전체 공진기법을 이용하여 초전도체 박막의 표면저항을 측정할 경우, 공진기의 $Q_U$로부터 초전도체 박막의 표면저항을 구하기 위해 알아야 하는 G-factor를 시뮬레이션과 전자기장 해석을 이용해서 구한 후 두 값을 비교하였다. 시뮬레이션 과정에서 사용된 mesh 수가 증가할수록 시뮬레이션으로 구한 G-factor의 크기와 전자기장 해석을 통해 얻은 값 간의 차이가 줄어들게 됨을 확인하였다. 공진기에 따라 mesh 수 증가에 따른 G-factor의 정확도 증가가 조금씩 다르게 나타났는데, 이는 공진기와 유전체의 크기에 따라 simulation program이 계산하는 개당 mesh의 크기가 각기 다르기 때문으로 여겨진다. 19.6 GHz의 공진주파수를 지닌 사파이어 공진기의 경우 시뮬레이션과 전자기장 해석을 통해 구한 G-factor의 차이를 이용하여 표면저항의 불확도 추정치를 온도의 함수로 구했으며 $Q_U$를 2 % 이내의 상대 불확도로 측정할 경우 G-factor의 불확도 변화에 따른 표면저항의 상대 불확도 변화를 확인하였다. 본 연구 결과는 전자기장 해석이 매우 어렵거나 불가능한 구조의 유전체 공진기 (예로서 open-ended 평행판 유전체 공진기)의 G-factor를 시뮬레이션을 이용하여 구하여 초전도체 박막의 표면저항을 $Q_U$로부터 측정하고자 할 때 측정 온도 구간에서 허용되는 표면저항의 불확도를 고려하여 G-factor의 시뮬레이션 시 사용되는 mesh 수가 결정되어야 함을 보여준다.

• Geomechanics and Engineering
• /
• 제32권6호
• /
• pp.615-625
• /
• 2023

Initial geometrical imperfection is an important factor affecting the structural characteristics of plate and shell structures. Studying the effect of geometrical imperfection on the structural characteristics of cylindrical shell is beneficial to explore the thermal post-buckling response characteristics of cylindrical shell. Therefore, we devote to investigating the thermal post-buckling behavior of graphene platelets reinforced mental foam (GPLRMF) cylindrical shells with geometrical imperfection. The properties of GPLRMF material with considering three types of graphene platelets (GPLs) distribution patterns are introduced firstly. Subsequently, based on Donnell nonlinear shell theory, the governing equations of cylindrical shell are derived according to Eulerian-Lagrange equations. Taking into account two different boundary conditions namely simply supported (S-S) and clamped supported (C-S), the Galerkin principle is used to solve the governing equations. Finally, the impact of initial geometrical imperfections, the GPLs distribution types, the porosity distribution types, the porosity coefficient as well as the GPLs mass fraction on the thermal post-buckling response of the cylindrical shells are analyzed.

• 한국공간정보시스템학회:학술대회논문집
• /
• 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
• /
• pp.83-88
• /
• 2004

First author proposed a proportioning method for member sections of a single layer reticulated dome subjected to uniform and non-uniform load without any geometrical initial imperfection, and discussed the validity and effectiveness of the method which was based on linear buckling stress and a knock down factor. However, buckling of a single layer reticulated dome is strongly affected by initial imperfection. It is well known that geometrical initial imperfections reduce the nonlinear buckling capacity of a single layer raticulated dome. Thus, structural engineers may be recommended to reflect the effects of geometrical initial imperfections in proportioning member sections. In this paper, firstly, the presented proportioning method by first author is applied to dome without consideration of any imperfections and the thickness and diameter of each member are determined. Secondly, the load bearing capacities of the proportioned domes are checked with the imperfection, by the inelastic buckling analysis.

• 한국전산유체공학회지
• /
• 제13권2호
• /
• pp.20-26
• /
• 2008

A numerical study is carried out to analyze the steady three-dimensional turbulent flow and convective heat transfer in a staggered pin-fin array with diamond shaped elements at various geometrical configurations. Steady Reynolds-averaged Navier-Stokes equations and energy equation are solved using a finite volume based solver. Shear stress transport (SST) model is used as turbulence closure. The computational domain is composed of one pitch of pin-fin displacement with periodic boundary conditions on the surfaces normal to the streamwise direction and the cross-streamwise direction. The numerical results for Nusselt number and friction factor are validated with experimental results. The effects of pin angle, pin height and pitch on Nusselt number, friction factor and efficiency index are investigated.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
• /
• pp.69-73
• /
• 2002

In ceramic systems, many components including embedded passives and TRL(transmission line) are used for composition of 3-dimensional circuit. So the exact analysis on this components, As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of stripline structure have a large effect on the charactersistics of transmission lines. In this research, of effect of material and geometrical factors on the characteristics of stripline structure is analyzed and quantified by simulation and measurement.