• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.5
• /
• pp.2375-2380
• /
• 2013

In this paper, we have implemented the unified fuel heater and performance evaluation system for diesel cars. In order to strengthen an engine starting of diesel car, we need to assembly the fuel filter and heater. Especially, this assembly fuel heater is very important in winter, it is necessary for heating to operate the diesel engine. The heater for unifying the sensor and heater body can advance the performance of car and reduce the production cost. Finally, the performance test chamber is needed to evaluate the performance of heater.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.211-211
• /
• 2008

태양열, 바람, 지열, 진동 등의 우리주변에서 쉽게 얻을 수 있는 에너지를 모아서 필요로 하는 전자기기의 에너지원으로 사용하는 개념의 에너지하비스팅에 대한 연구가 활발히 진행되고 있다. 기계적인 변경으로 전압이 발생하는 압전체는 오래전 알려져 있었지만 발생전압이 낮아 에너지발전용으로 적용이 힘들었다. 하지만 전자기기의 소형화와 함께 필요로 하는 전력도 수 ${\mu}W$로 낮아짐으로 압전체를 이용한 에너지하비스팅이 주목 받고 있다. 전선으로 연결하여 전원을 공급하기 힘든 위치에 있는 전자기기는 주기적으로 배터리를 교환해 주어야한다. 이는 시간적, 금전적, 인적자원의 낭비이며 반영구적으로 전원을 공급할 장치개발이 필요하다. 구조물은 수~ 수십 Hz로 진동을 하며 이 진동으로 압전체에 변형을 주어 전압을 발생시킨다. 변형이 클 때 발생전압도 크게 되므로 압전체를 칸틸레버형태로 제작했다. 더 큰 전압발생을 위해 메탈을 사이에 두고 양면에 압전체를 둔 바이몰프 형태로 캔틸레버를 제작했다. 이때 진동의 충격을 완화시켜 압전체에 인가되도록 하고 구조물의 고유진동수모다 큰 진동수로 압전체가 진동하도록 하기위해 스프링을 사용하여 제작하였다. 이 스프링 지지구조 및 가진 조건에 따른 발전특성을 알아보았다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.7
• /
• pp.526-534
• /
• 2013

With rapid rise of virtualization technology from diverse types of cloud computing service, security problems such as data safety and reliability are the issues at stake. Since damage in virtualization layer of cloud service can cause damage on all host (user) tasks, Hypervisor that provides an environment for multiple virtual operating systems can be a target of attackers. This paper propose a security structure for protecting Hypervisor from hacking and malware infection.

• Korean Journal of Metals and Materials
• /
• v.46 no.7
• /
• pp.420-426
• /
• 2008

By using electrodeposition, we developed a new method to produce Ni/Invar bimetal sheets, which have been used for the present study to investigate the texture evolution during annealing. The grains of electrodeposited Ni were columnar, while those of electrodeposited Fe-Ni alloy were nanocrystalline. These different parts of the bimetal underwent different evolution of textures and microstructures during annealing. In the nanocrystalline Invar, the as-deposited textures were of fiber-type characterized by strong <100>//ND and weak <111>//ND components, and the occurrence of grain growth resulted in the strong development of the <111>//ND fiber texture with the minor <100> // ND components. On the other hand, in the columnar-structured Ni part, the as-deposited <110>//ND fiber texture transformed to the <112>//ND fiber texture due to recrystallization occurring above $550^{\circ}C$. The development of microtextures which took place during annealing in the Ni/Invar interfacial regions was investigated by using the OIM analysis, and discussed in terms of the effect of atomic diffusion across the interfaces.

• Corrosion Science and Technology
• /
• v.22 no.6
• /
• pp.478-483
• /
• 2023

This study examined the corrosion behavior of bimetal materials composed of Fe-Ni alloy and Fe-Ni-Mo alloy, both suitable for use in electromagnetic switches. Electrochemical polarization and weight loss measurements revealed that, in contrast to Fe-Ni alloy, which exhibited pseudo-passivity behavior, Fe-Ni-Mo alloy had higher anodic current density, displaying only active dissolution and greater weight loss. This indicated a lower corrosion resistance in the Fe-Ni-Mo alloy. Equilibrium calculations for the phase fraction of precipitates suggested that the addition of 1 wt% Mo may lead to the formation of second-phase precipitates, such as Laves and M₆C, in the γ matrix. These precipitates might degrade the homogeneity of the passive film formed on the surface, leading to localized attacks during the corrosion process. Therefore, considering the differences in corrosion kinetics between these bimetal materials, the early degradation caused by galvanic corrosion should be prevented by designing a new alloy, optimizing heat treatment, or implementing periodic in-service maintenance.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.1
• /
• pp.12-18
• /
• 2007

As an arc fault interrupter, the AFCI mentioned in this paper has been designed to detect and interrupt arc faults due to wire deterioration, insulation, wire damage, loose connection, and excessive mechanical damage. Since AFCI is digital and uses mechanical and electric stress, the length of interruption against overload and over-current is much shorter than the current bi-metal method. Therefore, the risk of electrical fires has been reduced.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2017.05a
• /
• pp.138-138
• /
• 2017

차세대 CMOS 소자의 지속적인 고직접화를 위해서는 높은 gate capacitance와 낮은 gate leakage current를 확보를 위한, 적절한 metal gate electrode와 high-k dielectric 물질의 개발이 필수적으로 요구된다. 특히, gate dielectric으로 적용하기 위한 다양한 high-k dielectric 물질 후보군 중에서, 높은 dielectric constant와, 낮은 leakage current, 그리고 Si과의 우수한 열적 안정성을 가지는 Zr silicates 또는 Hf silicates(ZrSiO4와 HfSiO4) 물질이 높은 관심을 받고 있으며, 이를 원자층 증착법을 통해 구현하기 위한 노력들이 있어왔다. 그러나, 현재까지 보고된 원자층 증착법을 이용한 Zr silicates 및 Hf silicates 공정의 경우, 개별적인 Zr(또는 Hf)과 Si precursor를 이용하여 ZrO2(또는 HfO2)과 SiO2를 반복적으로 증착하는 방식으로 Zr silicates 또는 Hf silicates를 형성하고 있어, 전체 공정이 매우 복잡해지는 문제점 뿐 아니라, gate dielectric 내에서 Zr과 Si의 국부적인 조성 불균일성을 야기하여, 제작된 소자의 신뢰성을 떨어뜨리는 문제점을 나타내왔다. 따라서, 본 연구에서는 이러한 문제점을 개선하기 위하여, 하나의 precursor에 Zr (또는 Hf)과 Si 원소를 동시에 가지고 있는 DNS-Zr과 DNS-Hf bimetallic precursor를 이용하여 새로운 ZrSiO4와 HfSiO4 ALD 공정을 개발하고, 그 특성을 살펴보고자 하였다. H2O와 O3을 reactant로 사용한 원자층 증착법 공정을 통하여, Zr:Si 또는 Hf:Si의 화학양론적 비율이 항상 일정한 ZrSiO4와 HfSiO4 박막을 형성할 수 있었으며, 이들의 전기적 특성 평가를 진행하였으며, dielectric constant 및 leakage current 측면에서 우수한 특성을 나타냄을 확인할 수 있었다. 이러한 결과를 바탕으로, bimetallic 전구체를 이용한 ALD 공정은 차세대 고성능 논리회로의 게이트 유전물질에 응용이 가능할 것으로 판단된다.

• Journal of IKEEE
• /
• v.17 no.1
• /
• pp.63-70
• /
• 2013

In this paper, we have implemented the performance evaluation system of the unified fuel heater for CRDI diesel engine. If the diesel engine be cold by low temperature in winter, then that makes the waxing materials like a paraffin and is the source of poor engine starting. The unified fuel heater is the barrow meter that estimate the start performance of diesel engine, and be tested by test chamber. The chamber perform the normal temperature, an extremely low temperature, an operating performance in an extremely high temperature, the resistance operation delay time and current operation delay time in setting up test resistance, the bimetal delay time test in temperature variation, the current and resistor test of the composited heater, a heating operation test.

• Applied Chemistry for Engineering
• /
• v.33 no.5
• /
• pp.466-470
• /
• 2022

The catalytic thermal oxidizer process has recently attracted considerable attention for the oxidation and decomposition of volatile organic compounds at low temperatures (< 450 ℃) with high efficiency (> 95%). Although many noble metal catalytic materials are well established, they are expensive and hazardous. Herein, highly active and low-cost Cu-Mn bimetallic catalysts were prepared using a simple and facile synthesis method involving the co-precipitation of Cu and Mn precursors. The synthesis of the catalyst was optimized by controlling the composition ratio of Cu and Mn. The optimized catalyst exhibited a large surface area of 230.8 m²/g with a mesoporous structure. To demonstrate the catalytic performance, the Cu-Mn catalyst was tested for the oxidation reaction of ethyl acetate, showing a high conversion efficiency of 100% at a low temperature of 250 ℃.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.10 no.8
• /
• pp.921-926
• /
• 2015

For the over-heat protection purpose in power strip devices, over-current detection/protection circuits, such as bimetal, switching circuit, and microprocessor-based relay circuit, have been widely setup in high-end products. Most of these circuits are connected to the power line in parallel and, thus, they are sensitive to the line voltage and current distortion. Moreover, these protection circuits are often costly and, therefore, it is hard to meet the commercial requirements. A low-cost over-current detection circuit with the contactless current transducer is designed and tested in this paper. The detection circuit is galvanically isolated from the power line and, thus, less sensitive to the line voltage distortion. The experimental results show that the proposed circuit accurately operates despite of its simple structure and low-cost electronic parts.