• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.31 no.10
• /
• pp.876-883
• /
• 2007

Numerical simulations are conducted for the design of a micro thermal mass air flow sensor (MAFS), which consists of a microfabricated heater and thermopiles on the silicon-nitride ($Si_3N_4$) thin membrane structure. It is important to find the proper locations of these thermal elements in the design of MAFS with improved sensitivity. Three heating modes of the micro-heater are considered: constant temperature, constant power and heating pulses. The analyses are focused on the membrane temperature profile near the sensing section. Considered are the practical flow velocities, ranging from 3 m/s to 35 m/s, and the corresponding Reynolds numbers from 1000 to 10000. The results show that one of optimum sensing locations is about $100{\mu}m$ away from the microheater. It is concluded that the heating mode and configurations of thermal elements are the main factors for the MAFS with higher sensitivity.

• Journal of Korea Multimedia Society
• /
• v.23 no.2
• /
• pp.328-342
• /
• 2020

As the cloud-based ICT(Information & Communication Technology) infrastructure matures, the existing monolithic software development method is evolving into a micro-service structure based on cloud native computing. To develop and operate the services efficiently under the cloud native environment, DevOps-based application development plans through MSA(Micro Service Architecture) design based are essential. A cloud native environment is an approach to developing and running applications that take advantage of cloud computing models such as automation of source distribution, container-based virtualization, application scalability, resource efficiency, and flexible maintenance through object independence. To implement this approach, the utilization of key elements such as DevOps, continuous delivery, micro service, and containers is essential, but there are not enough previous studies on case analyses or application methods of these key elements. Therefore, in this paper, we analyze the cases of application development in cloud native environment and propose the optimized application development process and development method through small and medium-sized SI projects.

• Asian Journal of Atmospheric Environment
• /
• v.5 no.1
• /
• pp.56-63
• /
• 2011

Quantifying the solute composition of a cloud droplet (or a whole droplet) is an important task for understanding formation processes and heating/cooling rates. In this study, a combination of droplet fixation and SR-XRF microprobe analysis was used to visualize and quantify elements in a micro-scale droplet. In this study, we report the preliminary outcome of this experiment. A spherical micro-scale droplet was successfully solidified through exposure to ${\alpha}$-cyano-acrylate vapor without affecting its size or shape. An X-ray microprobe system equipped at the beam line 37XU of Super Photon ring 8 GeV (SPring-8) was applied to visualize and quantify the elemental composition in an individual micro-scale droplet. It was possible to reconstruct 2D elemental maps for the K and Cl contained in a microdroplet that was dispensed from the 10-ppm KCl standard solution. Multi-elemental peaks corresponding to X-ray energy were also successfully resolved. Further experiments to determine quantitative measures of elemental mass in individual droplets and high-resolution X-ray microtomography (i.e., 3D elemental distribution) are planned for the future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.363-366
• /
• 2005

A micro flow sensor on silicon substrate allows the fabrication of small components where many different functions can be integrated so that the functionality of the sensors can be increased. Further more, due to the small size of the elements the sensors can be quite fast. A thermal mass flow sensor measures the asymmetry of temperature profile around the heater which is modulated by the fluid flow. In normal, a mass flow sensor is composed of a central heater and a pair of temperature sensing elements around the heater. A new 2-D wide range micro flow sensor structure with three pairs of temperature sensors and a central heater was proposed and numerically simulated by the Finite difference formulation to confirm the feasibility of the flow sensor structure.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.12
• /
• pp.1619-1625
• /
• 2018

Portable electronic devices secondary batteries can cause fire and explosion due to micro-current change in addition to the situation of short-circuit inrush current, safety can not be secured with a general operation limited current fuse. Therefore, in secondary battery, it is necessary for the protector to satisfy both the limit current type operation in the open-short-circuit inrush current and the current detection operation characteristic in the micro current change situation and for this operation, a fuse for the current detection type secondary battery protection circuit can be applied. The purpose of this study is to design a protection device that operates stably in the hazardous situation of small capacity secondary battery for portable electronic devices through the design of low melting fuse elements alloy of sensing type fuse and secures stability in abnormal current state. As a result of the experiment, I-T and V-T operation characteristics are satisfied in a the design of the alloy of the current sensing type self-contained low melting point fuse and the resistance of the heating resistor. It is confirmed that it can prevent accidents of short circuit over-current and micro current change of secondary battery.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.4
• /
• pp.2265-2268
• /
• 2013

Several lines of evidence indicate that cancer is a multistep process. To survey the mechanisms involving gene alteration and miRNAs in adrenocortical cancer, we focused on transcriptional factors as a point of penetration to build a regulatory network. We derived three level networks: differentially expressed; related; and global. A topology network ws then set up for development of adrenocortical cancer. In this network, we found that some pathways with differentially expressed elements (genetic and miRNA) showed some self-adaption relations, such as EGFR. The differentially expressed elements partially uncovered mechanistic changes for adrenocortical cancer which should guide medical researchers to further achieve pertinent research.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.83-83
• /
• 2010

This study investigates the thermal and mechanical properties of insulation elements through mixing epoxy based micro- and nano particles. Regarding thermal properties, DSC and DMA were used to calculate crosslinking densities for various types of insulation elements. In a mechanical property of bending strength, shape and scale parameters were obtained using the Weibull plot. This study obtained the most excellent results of scale parameters, such as Vol 3.2%, in the bending strength of EMNCs.

• Journal of Technologic Dentistry
• /
• v.31 no.4
• /
• pp.9-15
• /
• 2009

The purpose of this study was to observe the change of mechanical property and microstructure in porcelain fused to gold alloy by heat treatment. PFG alloys are composed with Au-Pd-Ag alloy of the additional elements with indium, tin and copper. Specimens were tested in hardness using vicker,s micro-hardness tester and the surface micro structural changes were analysed by SEM and EDS. The results were as fellows: 1. The vickers hardness showed highest in Au-Pd-Ag alloy of the additional element with tin. 2. By hardening-oxiding result, the vicker,s hardness increased in additional element with tin but there was no significant difference in additional elements with indium and copper. 3. The surface oxide layer of Au-Pd-Ag alloy with added indium and tin increased but there was small change in additional element with copper. 4. The elements of indium and tin increased with increasing heat treatment in the surface alloy.

• The KSFM Journal of Fluid Machinery
• /
• v.18 no.4
• /
• pp.22-29
• /
• 2015

In this study, an in-house program to predict steady state operation of micro gas turbines is constructed using MATLAB. The program consists of two parts: design and off-design simulations. The program is fully modular in its structure, and performance of each component (compressor, combustor, turbine, recuperative heat exchanger and pipe elements) is calculated in a separate calculation module using mass and energy balances as well as models for off-design characteristics. The off-design modules of compressor and turbine use performance maps, which are program inputs. The off-design operation of a micro gas turbine under development was predicted by the program. The prediction results were compared with those by commercial software, and the validity of the in-house program was confirmed.

• Review of KIISC
• /
• v.23 no.4
• /
• pp.82-93
• /
• 2013

최근 새로운 지불결제 플랫폼인 스마트폰의 등장으로 모바일 금융 결제 비중이 지속적으로 증가하고 있다. 특히 금융microSD는 기존에 사용해오던 USIM의 불편함을 해소하고 보안성을 강화하여, 새로운 모바일 지불결제 수단으로써 IT업계와 금융업계의 지대한 관심을 받고 있다. 이에 금융microSD를 통해 모바일 지불결제가 또 다른 제2의 서비스로 융합하는 단초가 될 것으로 기대하고 있다. 본고에서는 모바일 지급결제 시장 현황 및 서비스 동향과 모바일 지급결제 서비스의 핵심 플랫폼으로 기능하는 Secure Elements(SE)를 유형별로 나누어 살펴보고, 금융 microSD 프레임워크를 분석하여 보안사항 및 활용방안 등에 대해 기술하고자 한다.