• 한국재료학회지
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• 제15권4호
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• pp.217-223
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• 2005

Thermal, electrical and mechanical properties of high purity niobium and tantalum refractory rare metals were investigated tn evaluate the physical purity. Higher purity niobium and tantalum metals showed lower hardness due to smaller solution hardening effect. Temperature dependence of electrical resistivity showed a typical metallic behavior. Remarkable decrease in electrical resistivity was observed for a high purity specimen at low temperature. However, thermal conductivity increased for a high purity specimen, and abrupt increase in thermal conductivity was observed at very low temperature, indicating typical temperature dependence of thermal conductivity for high purity metals. It can be known that reduction of electron-phonon scattering leads to increase in thermal conductivity of high purity niobium and tantalum metals at low temperature.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제9권2호
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• pp.25-30
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• 2020

열화상 시스템은 물체로부터 발산되는 적외선을 영상화하여 물체를 탐지하는 장점으로 인해 군수 분야에 많이 활용되었다. 그러나 Security 시스템과 자동차 시장에 수요가 증가함에 따라 민수 분야로 활용분야가 넓어지고 있다. 기존에는 대부분 FPGA 기반으로 열화상 열상 모듈을 개발하였지만 민수 분야에 다양한 요구사항 및 범용성에 유연한 대처가 힘든 실정이다. 따라서 다양한 요구사항과 범용성을 만족하기 위한 시스템의 필요성이 대두되었다. 본 논문에서는 멀티코어 이미지 프로세서를 이용한 열화상 영상 처리 시스템을 제안한다. 제안된 시스템은 기존 FPGA 기반 시스템이 아닌 멀티코어 이미지 프로세서를 사용함으로써 범용 영상 입·출력 인터페이스 및 각종 디바이스를 지원함에 따라 다양한 요구사항과 범용성을 만족한다. 따라서 시스템 구축 시 뛰어난 접근성으로 인하여 시스템 추가/변경으로 인한 개발 비용 및 기간을 단축할 수 있다. 이러한 장점으로 다양한 고객 요구사항 만족, 개발 비용 및 시간 단축, 제품 출시일 등 다양한 이점을 얻을 것으로 기대한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.535-537
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• 2004

The flame image processing and it's analysis system has been developed for optimal coal firing of thermal power plant, especially for reducing NOx and safe operations. We aimed at gaining the relationship between burner flame image, emissions of NOx and LOI(Loss on ignition) in furnace by utilizing the flame image processing methods. And the relationship determines quantitatively the conditions of combustion on the individual burners. The test was conducted on Samchonpo thermal power plant #4 unit(560MW) of KOSEP which has 24 burners. The system simplified the burner adjustment works in accordance with the real time trending of flame behavior like NOx profiles and unburned carbon profiles for individual burners. But, This kind of conventional method increases the cost as the number of burner are increased. Also there is a difficulty to measure exhausted gas of each burner because of measurement errors. This paper intends to propose the useful "Flame Monitoring System" that can find Low NOX and LOI at the upper furnace and to compare with the conventional System.

• 전기전자학회논문지
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• 제22권3호
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• pp.578-584
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• 2018

이미지 분할은 영상의 해석과 이미지 인식 분야에서 다양한 방법으로 연구되고 있으며, 특정한 목적에 따른 이미지의 특성을 분리하기 위해 사용된다. 본 논문에서는 열화상 이미지의 특징점인 고온을 검출하여 이미지를 분할하는 알고리즘을 제안한다. 또한 연산속도의 향상을 위해 제안하는 알고리즘을 Zynq-7000 Evaluation Board 환경에서 FPGA Hardware Block Design을 진행하였다. 고온 검출 알고리즘은 16ms에서 0.001ms의 속도 향상을 보였으며 전체 블록은 50ms에서 0.322ms로 속도 향상을 보이는 것을 확인하였다. 또한 영상 테스트벤치를 사용하여 소프트웨어와 하드웨어 이미지에 대해 유사한 PSNR 결과를 입증하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.221-225
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• 2009

A solar thermal collector is a solar collector specifically intended to collect heat: that is, to absorb sunlight to provide heat. A flat plate is the most common type of solar thermal collector, and is usually used as a solar hot water panel to generate solar hot water. A flat plate collector consists basically of an insulated metal box with a glass or a plastic cover and a dark-colored copper absorber plate. Solar radiation is absorbed by the copper absorber plate and transferred to water that circulates through the collector in copper tubes. Ultrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to work pieces being held together under pressure to create a solid-state weld. In this study, we developed solar collector ultrasonic welding machine with digital controlled power supply and tested various welding conditions such as welding pressure, welding amplitude, welding speed. Welding speed was considered in 2~12m/min. The width of ultrasonic welds was increased with welding amplitude by 2.2~2.5mm. The fracture load of ultrasonic welds showed 20% higher than domestic products.

• International Journal of Control, Automation, and Systems
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• 제6권2호
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• pp.160-170
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• 2008

Temperature control of an enclosed thermal system which has many applications including Rapid Thermal Processing (RTP) of semiconductor wafers showed an input-constraint violation for nonlinear controllers due to inherent strong coupling between the elements [1]. In this paper, a constrained nonlinear optimal control design is developed, which accommodates input constraints using the linear algebraic equivalence of the nonlinear controllers, for the temperature control of an enclosed thermal process. First, it will be shown that design of nonlinear controllers is equivalent to solving a set of linear algebraic equations-the linear algebraic equivalence of nonlinear controllers (LAENC). Then an input-constrained nonlinear optimal controller is designed based on that LAENC using the constrained linear least squares method. Through numerical simulations, it is demonstrated that the proposed controller achieves the equivalent performances to the classical nonlinear controllers with less total energy consumption. Moreover, it generates the practical control solution, in other words, control solutions do not violate the input-constraints.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 2004년도 추계학술대회논문집
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• pp.50-61
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• 2004

Nowadays Laser Controllable Thermo-cleaving is the most promising method of cutting FPD(Flat Panel Display) glass in mass-production line. And this method can be used to cut other brittle materials such as quartz, sapphire, ceramic and semiconductor. The concept of this method is shown in Picture 1. Laser beam heats glass up to strain point not to melting point and cooling system chills glass to make maximum thermal stress in glass and then the thermal stress generates micro thermal crack in other words blind crack. Laser Controllable Thermo-cleaving controls the thermal stress to optimize the blind crack up to level of mass-production line.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.424-427
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• 2018

The effect of oxygen pressure in the synthesis of $SnO_2$ micro/nanocrystals through thermal evaporation of Sn powder was investigated. The thermal evaporation process was performed at $1000^{\circ}C$ for 1 hr under various oxygen pressures. The pressure of oxygen changed from 10 to 500 Torr. The morphology of $SnO_2$ crystals changed drastically with oxygen pressure. $SnO_2$ nanoparticles with an average diameter of 120 nm were formed at oxygen pressure lower than 10 Torr. $SnO_2$ nanowires were grown under an oxygen pressure of 100 Torr. The nanowires have diameters in the range of 100 ~ 500 nm and lengths of several tens of micrometers. As increasing the oxygen pressure to 500 Torr, the sizes of wires increased. A strong visible emission peak centered at about 500 ~ 600 nm was observed in the room temperature cathodoluminescence spectra of all the products.

• 한국축산식품학회지
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• 제44권5호
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• pp.967-987
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• 2024

Recently, as the concept of pet food that satisfies both nutritional needs and the five senses has evolved, so too has the demand for effective pet food non-thermal sterilization methods. Prominent non-thermal technologies include high-pressure processing, plasma, and radiation, which are favored for their ability to preserve nutrients, avoid residues, and minimize compositional changes, thereby maintaining quality and sensory properties. However, to assess their effectiveness on pet food, it is essential to optimize operational parameters such as pressure levels, plasma intensity, radiation dosage, and temperature. Further studies are needed to evaluate microbial sterilization efficacy and sensory attributes. This exploration is expected to lay the groundwork for preventing zoonotic diseases and improving the production of high-quality pet food.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.711-716
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• 2001

This paper presents an information about the heat transfer characteristics of impinging jet in eletronic equipment with infrared image processing unit. There have been many experimental investigations and theoretical studies on impinging jet because of application in a wide variety of industrial process including electronic equipment. In this study, we used infrared image processing unit to visualize heat transfer characteristics of impinging jet in electronic equipment. Infrared image processing unit is one of non-contact temperature measuring methods and it is possible to minimize flow resistance and this measurement is comparatively accurate. The main parameters are nozzle exit angle $(30^{\circ},\;45^{\circ},\;60^{\circ},\;75^{\circ},\;90^{\circ})$ and distance between nozzle and heat source is fixed 6d("d" is diameter of circular nozzle(10 mm). Reynolds number is 4500.