• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
• /
• pp.781-786
• /
• 2017

본 연구는 달착륙선을 위한 하이브리드 추진 시스템의 기초 연구로서 동시 점화 및 산화제 유량 분배를 통한 클러스터링 연구를 수행하였다. 클러스터링 연소 실험을 위해 지상 연소 실험 시스템을 구축하였으며, 산화제와 연료는 각각 기체 산소(gas oxygen)와 고밀도 폴리에틸렌(High Density Poly Ethylene)을 사용하였다. 실험 결과 화약 점화를 사용한 동시 점화 장치는 동일한 시점에 점화가 되었으며, 유량 분배 장치를 통해 비교적 균일하게 산화제 분배가 이루어져 각 연소실 내에서의 압력이 비교적 동일하게 나타난 것을 확인하였다.

• 한국의상디자인학회지
• /
• 제15권1호
• /
• pp.47-57
• /
• 2013

In terms of expression, beauty illustration has become more diverse and innovative. Because of continued unique creative activities, more novelty has been pursued. In this study, beauty illustration in new artistic and decorative images was used to investigate the basic concepts of art activities, illustration and beauty illustration and make up for beauty illustration which adheres to traditional and classical expressions. In this study, the following results were obtained: First, in terms of expression of beauty illustration, the work with art expressions are still poor compared to other fields such as fashion illustration. Therefore, it is necessary to attempt beauty illustration of a new image which expresses artistic emotions. Second, by using an artistic technique called 'paper sculpture', a semi-solid shape has been completed, and a decorative beauty illustration was created. People get new inspiration through beautiful and innocent art pieces, which in turn motivate to create new expression. New art activities which take a human body as an art support beauty activities through picture and more sensitive inspiration. It was attempted to express other emotion and beauty by observing a single piece of work. A new possibility in beauty illustration which is differentiated from other art activities is proposed and its domain is developed.

• 한국전기전자재료학회논문지
• /
• 제27권10호
• /
• pp.673-677
• /
• 2014

In this paper, thermal analysis of HDU (Heat Dissipation Unit) for infrared CCTV is performed by using SolidWorks Simulation (Thermal analysis) package, in order to change the part materials and HDU shape is optimized. Furthermore, HDU disperses the aggregated heat around the LED inside the housing. The junction temperature of infrared LED checked by HDU check was $65.83^{\circ}C$, $42.02^{\circ}C$, respectively. In addition, the Thermoelement by changing the shape of the HDU was possibly designed and equipped with. Comparison with simulation and prototype measurement results, without HDU model was $65.83^{\circ}C$, $61.99^{\circ}C$, respectively. In addition to with HDU model was $42.02^{\circ}C$, $39.01^{\circ}C$, respectively. Only HDU mounted into infrared CCTV is usable in the ordinary house or outdoors. Also HDU with thermal element, fan mounted into infrared CCTV is usable in a blast furnace workplace or high temperature workplace.

• 한국정밀공학회지
• /
• 제22권5호
• /
• pp.152-158
• /
• 2005

Inner structured and bonded panel, or ISB Panel, as a kind of sandwich type panel, has metallic inner structures which have low relative density, due to their dimensional shape of metal between a pair of metal skin sheets or face sheets. Previous works showed that ISB panels containing inner structures formed as repeated pyramidal shapes saved weight up to $60\%$ in condition of same stiffness comparing with solid sheet. In this work, woven metal is adapted to inner structures replacing pyramidal structures. The test specimens of ISB panel containing woven metal made by multi-point electric resistance welding and 3-point bending test have been carried out. The results of experiments and comparisons of process parameters, stiffness and failure mode are discussed.

• 대한기계학회논문집B
• /
• 제26권2호
• /
• pp.302-309
• /
• 2002

A new method of measuring the thermal diffusivity of solid material at room temperature using photothermal displacement is proposed. The influence of the parameters, such as radius and modulation frequency of the pump beam and the sample thickness, was studied. In previous works, thermal diffusivity was determined by the deformation angle and phase angle as the relative position between the heating and probe beams. In this study, however, we proposed the new analysis method based on the real part of deformation angle as the relative position between two beams. From the zero-crossing position of real part of deformation angle with respect to the pump beam, the thermal diffusivity of the materials can be obtained. The experimental values for different samples obtained by applying the new method are in good agreement with the literature values.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제45권1호
• /
• pp.43-47
• /
• 2019

The characteristics of extra-nasopharyngeal angiofibromas tend to be different from angiofibromas of the nasopharynx according to patient gender, patient age, prevalence, affected site, pathogenesis, and clinical and epidemiological features. We report a case of an extra-nasopharyngeal angiofibroma in a 28-year-old man referred to the ENT Clinic for right-sided epistaxis, airflow impairment and nasal swelling. The right nostril was completely occluded works by a reddish-yellow mass that bled easily. The computed tomography scan revealed an "inhomogeneous solid lesion in the nasal fossa". With the patient under general anesthesia, the formation in the anterior portion of the right side of the nasal septum was removed up to its vascular base. Although electrical cauterization efficiently controlled the bleeding, we abraded the sub-perichondral area to prevent further bleeding as well as recurrence. The histological exam report confirmed the diagnosis of angiofibroma. As in our case, epistaxis is commonly the presenting sign of angiofibroma. Yet its onset was peculiar, given that the bleeding started with a low impact trauma. The nasal swelling was also a relevant feature as well as the breathing impairment. Although uncommon, nasal septal angiofibromas should considered in patients with epistaxis.

• 한국기계가공학회지
• /
• 제17권5호
• /
• pp.1-7
• /
• 2018

Flexible track drilling machines are credited with important applications in the area of aircraft manufacturing because of their portability, quick installation capabilities, and high efficiency. However, their structures are special and the constitution principles and motion characteristics are difficult to control, increasing the development costs and research cycle in the context of the technology blockade of foreign companies. The simulation analysis of flexible track drilling machines can be conducted by applying virtual prototypes, shortening the development cycle and reducing the cost. In this paper, a model of a machine is established by using the SolidWorks software and imported into ADAMS to conduct kinematic and dynamic simulation analysis. During the analysis, the feasibility of the configuration is checked, a reasonable driving motion is chosen, potential deficiencies are found, and improvement actions are raised.

• 한국기계가공학회지
• /
• 제18권6호
• /
• pp.106-112
• /
• 2019

Rotary swaging is a method of forging automotive drive shafts. In this paper, we propose a new two-hammer forging technique by applying the problem-solving approach TRIZ to improve the efficiency and productivity of the rotary swaging automation process. We will simplify the materials and hammers via the 3D modeling tool SolidWorks for high accuracy of a comparative analysis of existing and proposed methods under the same boundary conditions. In addition, we will compare the stress trends of the proposed model using ANSYS Workbench and verify the feasibility through a comparison of the simulation results using DEFORM. Relative to the existing method, the proposed method can decrease production costs and improve efficiency of the automation process by reducing the power source.

• Composites Research
• /
• 제31권6호
• /
• pp.355-364
• /
• 2018

Flexible energy-storage devices (FESDs) have been studied and developed extensively over the last few years because of demands in various fields. Since electrochemical performance and mechanical flexibility must be taken into account together, different framework from composition of conventional energy-storage devices (ESDs) is required. Numerous types of electrodes have been proposed to implement the FESDs. Herein, we review the works related to the FESDs so far and focus on free-standing electrodes and, especially substrate-based ones. The way to utilize carbon woven fabric (CF) or carbon cloth (CC) as flexible substrates is quite simple and intuitive. However, it is meaningful in the point of that the framework exploiting CF or CC can be extended to other applications resulting in multifunctional composites. Therefore, summary, which is on utilization of carbon-based material and conductive substrate containing CF and CC for ESDs, turns out to be helpful for other researchers to have crude concepts to get into energy-storage multi-functional composite. Moreover, polymer electrolytes are briefly explored as well because safety is one of the most important issues in FESDs and the electrolyte part mainly includes difficult obstacles to overcome. Lastly, we suggest some points that need to be further improved and studied for FESDs.

• 한국가시화정보학회지
• /
• 제18권3호
• /
• pp.42-51
• /
• 2020

This study performs a numerical simulation of lid driven rectangular cavity flow with different aspect ratios of k = 0.5 to 4 under Reynolds 100, 1,000, 10,000 by using multi-relaxation time (MRT) Lattice Boltzmann Method (LBM). In order to achieve better convergence, well-posed boundary conditions in the domain should be defined such as no-slip condition on side and bottom solid wall surfaces and uniform horizontal velocity on the top of the cavity. This study focuses on the flow inside different shape of rectangular cavity with the aim to observe the effect of the Reynolds number and aspect ratio on the flow characteristics and primary/secondary vortex formation. In order to validate the study, the results have been compared with existing works. The result shows that the Reynolds number and the aspect ratio both has substantial effects on the flow inside the lid-driven rectangular cavity.