• 한국의상디자인학회지
• /
• 제5권1호
• /
• pp.59-71
• /
• 2003

The purpose of this study is to provide for the basic data useful to the development of a quality brassiere featuring a good wearing feeling and an effect of reinstating and correcting breast shape. For this purpose, 220 adult women aged between 20 and 59 were sampled to survey their perceived and actual breast shapes. The results of this study can be summarized as follows; 1. Most adult women correctly perceive the changes of their breast shapes as they become older. However, the younger women tend to evaluate their breast as larger than their actual sizes, being more dissatisfied with their breast shapes than older women, while wanting their constitution to be more high and slim. In short, there is a little difference between their perceived and actual breast shapes. 2. The breast shape perceived most by the adult women is "droopy type I"(37.7%), followed by "conical type"(21.8%), "flat type"(16.8%), "semi-circular"(10.8%), "droopy type II"(8.6%) and "extruded type"(5.0%) in their order. The younger women tend to perceive their breasts as "flat", "conical" or "semi-circular", while the older women tend to perceive their breasts as "droopy". 3. According to the increase of age, the items of height were decreased and items of width, depth, circumference and length were increased, being obser and breast point were drooped. so volume and bottom area of breast of 40ㆍ50's women's age group were larger than 20?30's women's age group and breast point width of 40ㆍ50's women was being wider by increase of interior dimensions of breast.

• 식물분류학회지
• /
• 제35권4호
• /
• pp.313-335
• /
• 2005

식물규소체는 토양과 물에 용해된 규소가 이산화규소($SiO_2$)의 형태로 식물체내의 여러 기관 또는 표피세포에 축적되면서 형성되어 식물의 성장과 발달에 중요한 영향을 미치는 것으로 밝혀지고 있어, 식물의 규소체에 관한 연구가 시행되고 있다. 따라서 본 연구에서는 한국산 사초과 (Cyperaceae) 식물 13속 228종 중, 12속 136종의 잎의 표피형에서 밝힌 규소체의 형태를 검토하여 정리하였다. 그 결과 한국산 사초과 식물은 규소체의 모양에 따라 2 그룹으로 구분되었다. 제 1 그룹은 원추형(conical body)의 규소체를 나타내고, 골풀아재비속(Rhynchospora), 검정방동산이속(Fuirena), 너도고랭이속(Scleria), 사초속(Carex)과 황새풀속(Eriophorum)이 이에 속한다. 제 2 그룹은 규소체의 모양이 원추형을 중심으로 많은 위성형을 보이며, 방동산이속(Cyperus), 올챙이골속(Scirpus), 바늘골속(Eleocharis), 하늘지기속(Fimbristylis), 파대가리속(Kyllinga), 모기골속(Bulbostylis)과 세대가리속(Lipocarpha.)이 속한다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2009년도 추계학술대회 논문집
• /
• pp.176-181
• /
• 2009

In this article, excitation forces due to unbalance mass in a flywheel energy storage system will be discussed, which mainly consists of a composite flywheel and active magnetic bearings and a motor/generator. Unbalance mass causes moments as well as centrifugal forces to the center of the flywheel when the flywheel rotates. The moment excites the flywheel to revolve in the shape of conical revolution and in real operation, the flywheel shows an aspect that conical revolution is a main mode when system failure occurs. Although there are several excitation sources to the flywheel including unbalance mass, an excitation from motor and control issues of the magnetic bearings, we could infer unbalance mass is the main cause of the failure from a comparison between a composite flywheel and a steel flywheel in the same condition. In this of view, excitation forces and moments induced by unbalance mass should be carefully considered in dynamics of the flywheel so that the energy storage system can be operated in more stable conditions.

• Journal of electromagnetic engineering and science
• /
• 제7권3호
• /
• pp.138-146
• /
• 2007

In this paper, a monopole antenna of conical-cylindrical compound shape is presented. The conventional circular conical monopole antenna is modified by placing a cylinder at the top of the inverted cone. The cylindrical portion is useful in the wide band impedance matching, in adjusting the antenna gain in the horizontal direction, and in reducing the cone diameter. The dependence of the antenna performance on various geometric parameters is investigated using a commercial electromagnetic simulation software, from which an optimum design of the antenna is derived. The diameter of the circular ground plane is minimized to 115 wavelength at the lowest operating frequency. The antenna proposed in this study shows a reflection coefficient less than -10 dB and a 1${\sim}$6 dBi gain over 3${\sim}$20 GHz frequencies. The antenna shows a circular-symmetric radiation pattern in the horizontal plane and a null-free pattern in the vertical direction over the whole operating frequency range.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 제35회 춘계학술대회
• /
• pp.169-176
• /
• 2002

Axial crushing behavior of cylindrical shell Is utilized in the braking of the high-velocity impacting object. In this paper, truncated cone shape brake device is introduced. That is, thickness of the shell is increased gradually from the impacting end to the other end. A detailed experimental investigation on the quasi-static axial crushing behavior of truncated cone type brake devices has been performed. Specimens of various shape were tested to check the influence of design parameters such as length, radius, mean thickness, and conical angle of cylinder. Influence of the material properties were also investigated by adopting aluminum, low carbon steel, and stainless steel as constructing materials. By analyzing deformation procedures of the specimens, it is seen that conical angle influence the deformation mode and the sequence of the wrinkles generation. Braking distance and mean braking force of each specimen were predicted based on the crushing load measured from the tests.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.1455-1460
• /
• 2000

When a tube is oscillated at a resonant frequency, acoustic variables such as density, velocity, and pressure undergo very large perturbation, often described as nonlinear oscillation. In order to analyze these phenomena, nonlinear governing equation has been drived and solved numerically. Numerical simulations were accomplished to study the effect of the tube shape on the maximum pressure we can obtain. The tubes of cylindrical, conical, and cosine-shape, which have same volume and length, were investigated. Results show that the resonant frequency and patterns of pressure waves strongly depend on not only the tube shape but also the amplitude of driving acceleration. The degree of non-linearity of wave patterns was also measured by the newly defined nonlinear energy ratio of the pressure signals. It was found that the 1/2 cosine-shape tube is more suitable to induce high compression ratio than other shapes.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.824-827
• /
• 2003

The study of Sealless Cylinder is presented. The cylinder has a piston with air bearing. The piston has a partly cylindrical and partly conical shape. The description of system geometry is follows by the flow rate equations. Then pressure distribution and Bearing force equations are derived. Several non dimensional parameters are suggested. The relationship among bearing force, leakage flow and geometry of the bearing is investigated by simulation. And determination method for optimal design of sealless cylinder is given. A prototype of seatless cylinder which had rod bearing with four pockets, five pockets, and six pockets was built respectively.

• Wind and Structures
• /
• 제24권1호
• /
• pp.25-41
• /
• 2017

The effects of finite cylinder free end shape on the mean and fluctuating wind pressures were investigated experimentally and numerically by using three different roof shapes: flat, conical and hemispherical. The pressure distributions on the roofs and the side walls of the finite cylinders partially immersed in a simulated atmospheric boundary layer have been obtained for three different roof shapes. Realizable $k-{\varepsilon}$ turbulence model was used for numerical simulations. Change in roof shapes has caused significant differences on the pressure distributions. When compared the pressure distributions on the different roofs, it is seen from the results that hemispherical roof has the most critical pressure field among the others. It is found a good agreement between numerical and experimental results.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 추계학술대회
• /
• pp.1911-1915
• /
• 2003

The study of Sealless Cylinder is presented. The cylinder has a piston with air bearing. The piston has a partly cylindrical and partly conical shape. The description of system geometry is follows by the flow rate equations. Then pressure distribution and Bearing force equations are derived. Several non dimensional parameters are suggested. The relationship among bearing force, leakage flow and geometry of the bearing is investigated by simulation. And determination method for optimal design of sealless cylinder is given. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was built respectively.

• 소성∙가공
• /
• 제18권1호
• /
• pp.80-86
• /
• 2009

This paper presents the plastic inhomogeneous deformation behavior of bimetal composite rods during the axisymmetric and steady-state extrusion process through a conical die. The rigid-plastic FE model considering frictional contact problem was used to analyze the co-extrusion process with material combinations of Cu/Al. Different cases of initial geometry shape for composite material were simulated under different conditions of co-extrusion process, which includes the interference and frictional conditions. From the simulation results, the sleeve cladding rate at the core/sleeve interface was recorded as a distribution of diameter ratio and interference conditions, which will be useful for the investigations of the bonding process during co-extrusion process. In addition, the results of the co-extrusion, connected with the results of the variations of diameter rate and average contact pressure, demonstrate a good agreement and present the possibility of describing the parameters of the plastic zones in non-uniform deformation of these type of composite materials.