• 한국세라믹학회지
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• 제54권2호
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• pp.75-85
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• 2017

Thermoelectric is a key technology for energy harvesting and solid-state cooling by direct thermal-to-electric energy conversion (or vice versa); however, the relatively low efficiency has limited thermoelectric systems to niche applications such as space power generation and small-scale or high-density cooling. To expand into larger scale power generation and cooling applications such as ATEG (automotive thermoelectric generators) and HVAC (heating, ventilation, and air conditioning), high-performance bulk thermoelectric materials and their low-cost processing are essential prerequisites. Recently, the performance of commercial thermoelectric materials including $Bi_2Te_3$-, PbTe-, skutterudite-, and half-Heusler-based compounds has been significantly improved through non-equilibrium processing technologies for defect engineering. This review summarizes material design approaches for the formation of multi-dimensional and multi-scale defect structures that can be used to manipulate both the electronic and thermal transport properties, and our recent progress in the synthesis of conventional thermoelectric materials with defect structures is described.

• 한국통신학회논문지
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• 제27권4B호
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• pp.365-371
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• 2002

본 논문에서는 전자선 묘화 장비를 이용하여 게이트 길이가 0.2 $\mu\textrm{m}$ 이하인 밀리미터파용 전력 PHEMT 소자를 제작하고 DC 특성과 주파수 특성 그리고 전력 특성을 측정하고 분석하였다. PHEMT의 제작에 사용된 단위공정은 저 저항 오믹 접촉, 에어 브릿지 및 후면 가공 공정기술 등을 이용하였다. 제작된 전력용 PHEMT는 35 GHz의 중심주파수에서 4 dB의 S21 이득과 317 mS/mm의 최대 전달컨덕턴스 그리고 62 GHz의 차단주파수와 12G GHz의 최대 공진주파수를 나타내었다. 또한 측정된 전력 특성은 35.5 %의 드레인 효율과 16 dB의 최대 출력전력 그리고 4 dB의 전력 이득을 나타내었다.

• 한국소프트웨어감정평가학회 논문지
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• 제15권1호
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• pp.103-107
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• 2019

최근 저전력 고속 디지털 데이터 통신을 구현 하기위해 많은 기술들이 개발되고 있는 추세이며 듀티사이클 보정에 관련된 기술도 그중 하나이다. 본 논문에서는 전압제어 링 발전기용 저-면적 듀티사이클 보정 회로를 제안하였다. 듀티사이클 보정 회로는 전압제어 링 발진기의 180도 위상차이를 이용하여 듀티사이클을 보정하는 회로이며, 제안된 저-면적 듀티사이클 회로는 기존의 플립플롭을 TSPC(True Single Phase Clocking) 플립플롭으로 변경하여 회로를 구성하였고 이로 인하여 저-면적 고성능 회로를 구현하였다. 일반적인 플립플롭을 대신하여 TSPC플립플롭을 사용하여 기존 회로 대비 저-면적으로 회로 구현이 가능하며 고속 동작에 용이하여 저-전력용 고성능 회로에 활용될 것으로 기대된다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 PARALLEL CFD 2006
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• pp.35-40
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• 2006

The insatiable desire of consumers to want more and more performance from computer equipment has driven the powers of this equipment to levels that are putting a strain on the thermal management of data centers housing this equipment. Equipment powers have been rising steadily over the past 10 years at a rapid rate. When the industry switched from bipolar to CMOS back in the early 90's industry experts had thought that the low power CMOS technology would resolve all problems associated with power and heat. Little did they know that now the problems associated with the CMOS equipment has surpassed anything installed with the bipolar technologies 10 to 15 years ago. Data centers are being designed with 15 to 20 years life spans and customers we asking how to plan for the power and cooling within these data centers. This paper addresses some of the current issues with cooling of equipment in data centers and describes some of the on-going efforts to under the thermal environment. To set the stage far describing the data center thermal management issues the power trends from the microprocessor to the rack will be described.

• 대한안전경영과학회지
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• 제24권2호
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• pp.1-9
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• 2022

In korea, 500MW standard coal fired power plants were designed and operated for the initial base load, so facility stability was prioritized from facility problem to treatment, but now we needed to research for minimizing greehouse gas emissions at the operation of coal fired power plants. research on various facilities and technologies was actively conducted to reduce environment pollutants was drastically reduced, but research and attempts on coping measures in the event of a reduction facility problem were in sufficient. this study considered investigated ways to minimized pollutants by quickly responding to logic development and application of the load runback concept in case of serious problems with environmental pollutant reduction facilities such as NOx reduction selective catalytic reduction facilities, SOx reduction wet flue gas desulpherisation facilities, and TSP(Total Suspended Particles) collection low temperature electric precipitator.

• 한국전자통신학회논문지
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• 제18권2호
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• pp.291-298
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• 2023

SRAM 기반 인 메모리 컴퓨팅은 폰 노이만 구조의 병목 현상을 해결하는 기술 중 하나이다. SRAM 기반의 인 메모리 컴퓨팅을 구현하기 위해서는 효율적인 SRAM 비트 셀 설계가 필수적이다. 본 논문에서는 전력 소모를 감소시키고 회로 성능을 개선시키는 저 전력 차동 감지 8+T SRAM 비트 셀을 제안한다. 제안하는 8+T SRAM 비트 셀은 SRAM 읽기와 비트 연산을 동시에 수행하고 각 논리 연산을 병렬로 수행하는 리플 캐리 가산기에 적용한다. 제안하는 8+T SRAM 기반 리플 캐리 가산기는 기존 구조와 비교 하여 전력 소모는 11.53% 감소하였지만, 전파 지연 시간은 6.36% 증가하였다. 또한 이 가산기는 PDP(: Power Delay Product)가 5.90% 감소, EDP(: Energy Delay Product)가 0.08% 증가하였다. 제안한 회로는 TSMC 65nm CMOS 공정을 이용하여 설계하였으며, SPECTRE 시뮬레이션을 통해 타당성을 검증하였다.

• 센서학회지
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• 제23권4호
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

• 한국도로학회논문집
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• 제16권6호
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• pp.51-57
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• 2014

PURPOSES : An conventional method for electric power generation is converting thermal energy into mechanical energy then to electrical energy. Due to environmental issues such as global warming related with $CO_2$ emission etc., were the limiting factor for the energy resources which resulting in extensive research and novel technologies are required to generate electric power. Thermal energy harvesting using thermoelectric generator is one of energy harvesting technologies due to diverse advantages for new green technology. This paper presents a possibility of application of the thermoelectric generator's application in the direct exchange of waste solar energy into electrical power in road space. METHODS : To measure generated electric power of the thermoelectric generator, data logger was adopted as function of experimental factors such as using cooling sink, connection methods etc. Also, the thermoelectric generator、s behavior at low ambient temperature was investigated as measurement of output voltage vs. elapsed times. RESULTS : A few temperature difference between top an bottom of the thermoelectric generator is generated electric voltage. Components of an electrical circuit can be connected in various ways. The two simplest of these are called series and parallel and occur so open. Series shows slightly better performance in this study. An installation of cooling sink in the thermoelectric generator system was enhanced the output of power voltage. CONCLUSIONS : In this paper, a basic concepts of thermoelectric power generation is presented and applications of the thermoelectric generator to waste solar energy in road is estimated for green energy harvesting technology. The possibility of usage of thermoelectric technology for road facilities was found under the ambient thermal gradient between two surfaces of the thermoelectric module. An experiment results provide a testimony of the feasibility of the proposed environmental energy harvesting technology on the road facilities.

• 한국수소및신에너지학회논문집
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• 제33권5호
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• pp.591-597
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• 2022

Recently, technologies for efficient power grid operation have become important due to climate change. For this reason, predicting power demand using deep learning is being considered, and it is necessary to understand the influence of characteristics of each region, industrial structure, and climate. This study analyzed the power demand of New Jersey in US, with a high urbanization rate and a large service industry, and West Virginia in US, a low urbanization rate and a large coal, energy, and chemical industries. Using recurrent neural network algorithm, the power demand from January 2020 to August 2022 was learned, and the daily and weekly power demand was predicted. In addition, the power grid operation based on the power demand forecast was discussed. Unlike previous studies that have focused on the deep learning algorithm itself, this study analyzes the regional power demand characteristics and deep learning algorithm application, and power grid operation strategy.

• 전자통신동향분석
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• 제34권5호
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• pp.14-25
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• 2019

As the Internet of Things, artificial intelligence and big data have received a lot of attention as key growth engines in the era of the fourth industrial revolution, data acquisition and utilization in mobile, automotive, robotics, manufacturing, agriculture, health care and national defense are becoming more important. Due to numerous data-based industrial changes, demand for sensor technologies is exploding, especially for intelligent sensor technologies that combine control, judgement, storage and communication functions with the sensors's own functions. Intelligent sensor technology can be defined as a convergence component technology that combines intelligent sensor units, intelligent algorithms, modules with signal processing circuits, and integrated plaform technologies. Intelligent sensor technology, which can be applied to variety of smart IT convergence services such as smart devices, smart homes, smart cars, smart factory, smart cities, and others, is evolving towards intelligent and convergence technologies that produce new high-value information through recognition, reasoning, and judgement based on artificial intelligence. As a result, development of intelligent sensor units is accelerating with strategies for miniaturization, low-power consumption and convergence, new form factor such as flexible and stretchable form, and integration of high-resolution sensor arrays. In the future, these intelligent sensor technologies will lead explosive sensor industries in the era of data-based artificial intelligence and will greatly contribute to enhancing nation's competitiveness in the global sensor market. In this report, we analyze and summarize the recent trends in intelligent sensor technologies, especially those for four core technologies.