• 한국연소학회지
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• 제22권1호
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• pp.8-13
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• 2017

Ignition delay time of methane/oxygen mixture is measured experimentally with the shock tube in order to obtain the data for high pressure conditions where gas turbines and internal combustion engines are operating. The shock tube experiment is validated first over the temperature range of 1400-2000 K at 10 bar and with the various equivalence ratios of 0.5, 1 and 2. The measured ignition delays are compared with the data from the literatures. And then, experiments are conducted for non-explored conditions, i.e., at 40 bar and with the equivalence ratio of 1.5. The present experimental data show a good agreement with the available ones from the literatures and reasonable dependence on pressure and equivalence ratio. In addition, the effects of the temperature and equivalence ratio on ignition delay time are analyzed.

• 설비공학논문집
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• 제20권1호
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• pp.11-16
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• 2008

Infrared (IR) detectors are widely used for such applications as thermoelastic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Thermal load of a cryochamber is attributed to the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector cryochamber with a radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation.

• 설비공학논문집
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• 제16권10호
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• pp.889-894
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• 2004

Infrared (IR) detectors are widely used for many applications, such as temperature measurement, intruder and fire detection, robotics and industrial equipment, thermoelstic stress analysis, medical diagnostics, and chemical analysis. Quantum detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Thermal analysis of cryochamber includes the conduction heat transfer through a cold well, the gases conduction and gas outgassing, as well as radiation heat transfer, The transient cooling characteristics of an infrared detector cryochamber are investigated experimentally in the present study. The transient cooling load increases as the gas pressure is increased. Gas pressure becomes significant as the cooling process proceeds. Cool down time is also increased as the gas pressure is increased. It is also found that natural convection effects on cool down time become significant when the gas pressure is increased.

• 한국전자파학회논문지
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• 제21권9호
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• pp.1013-1022
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• 2010

원격으로 지표면 온도를 측정하는 C-대역 라디오미터를 설계하고, 아스팔트를 대상으로 실시한 측정 결과를 제시하였다. 높은 감도와 낮은 전력 소모를 위해 전전력(total power)형 라디오미터 형태를 선택하였고, 안정적으로 높은 이득을 확보하기 위해 슈퍼헤테로다인(super-heterodyne) 방식으로 설계하였다. 중심 주파수 5.1 GHz에서 110 MHz의 대역폭을 가지도록 설계된 라디오미터는 59 dB의 이득과 2.7 dB의 잡음 지수를 가지며, 0.45 K의 수신 감도를 가진다. 제작된 시스템과 온도계를 사용해 아스팔트의 지표면 온도를 측정하였다. 그리고 각각의 측정 결과를 분석하여 설계된 라디오미터가 온도 변화에 대해 6 $mV/^{\circ}C$의 전압 변화율을 가지고 선형적으로 동작함을 보였다. 이를 통해 설계된 C-대역 라디오미터의 지표면 원격 온도 측정 센서로의 적용 가능성을 검증하였다.

• 한국식품과학회지
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• 제19권2호
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• pp.129-133
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• 1987

마이크로컴퓨터를 식품가공 공정및 연구에서 자료수집및 제어에 응용하기 위하여 Apple ll 컴퓨터에 접속가능한 접속장치(接續裝置)를 설계 제작하였다. 또한 식품의 여러 공정에 주요한 변수가 되는 온도 및 무게값을 전기적 신호로 감지하는 센서와 A/D변환기(變換器)의 적정 입력전압범위 전환을 위한 증폭회로를 구성하였다. 이들을 연결시켜 필요한 BASIC어(語) 프로그램을 작성하여 식품건조 장치의 온도및 무게값의 측정장치로 활용 가능함을 보였다. 컴퓨터를 응용함으로써 공정자료의 정확성과 신뢰성을 향상시키고 여러가지 공정변수를 다량 수집할 수 있게되고 수집된 많은 자료를 용이하게 저장, 분석할 수 있었다. 본 실험장치에 여러가지 목적에 따라 필요한 측정 센서를 개발하여 부착(附着)함으로 비단 온도와 무게 측정뿐 아니라 제반(諸般)식품(食品)제조 공정과 실험의 자동화에 활용할 수 있는 기초적인 자료를 얻었다.

• International Journal of Computer Science & Network Security
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• 제22권8호
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• pp.371-379
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• 2022

The environment in Kosovo is a topic of concern for the citizens and the state because of the temperatures that affect the health of the citizens and the climate around the world. Kosovo's climate is related to its geographical position. Stretching in the middle latitude, Kosovo's climate depends on the amount of heat coming from the Sun, the proximity of the Adriatic Sea, the Vardar valley, the openness to the north. In order to better understand the climatic features of Kosovo, one must know the elements of the climate such as: sunshine, temperature, precipitation, atmospheric pressure, winds. The Meteorological Institute of Kosovo is responsible for measuring temperatures in Kosovo since 2014 and until now 12 meteorological stations have been operationalized with automatic measurement and real-time data transfer to the central system for data collection and archiving. The hydrometeorological institute lacks an application for measuring temperatures in all the countries of Kosovo. Software applications are generally built to suit the requirements of different governments and clients in order to enable easier management of the jobs they operate on. One of the forms of application development is the development of mobile applications based on android. The purpose of the work is to create a mobile application based on the Android operating system that aims to display information about the weather, this type of application is necessary and important for users who want to see the temperature in different places in Kosovo, but also the world. This type of application offers many options such as maximum temperature, minimum temperature, humidity, and air pressure. The built application will have real and accurate data; this will be done by comparing the results with other similar applications. Such an application is necessary for everyone, especially for those people whose daily work is dependent on the weather or even for those who decide to spend their vacations, such as summer or winter. In this paper, comparisons are also made within android applications for tablets, televisions and smart watches.

• 반도체디스플레이기술학회지
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• 제22권3호
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• pp.119-124
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• 2023

In this study, experimental approach of the measurement of condensation and evaporation heat transfer coefficients is discussed for mixed refrigerants using in the ultra low-temperature cooling system for semiconductor etching process. An experimental apparatus was described performing the condensation and evaporation heat transfer measurements for mixed refrigerants. The mixed refrigerant used in this study was composed of the optimal mixture determined in previous research, with a composition of Ar:R14:R23:R218 = 0.15:0.4:0.15:0.3. The experiments were conducted over a temperature range from -82℃ to 15℃ and at pressures ranging from 18.5 bar to 5 bar. The convection heat transfer coefficients of the mixed refrigerant were measured at flow rates corresponding to actual operating conditions. The condensation heat transfer coefficient ranged from approximately 0.7 to 0.9 kW/m2K, while the evaporation heat transfer coefficient ranged from 1.0 to 1.7 kW/m2K. The detailed discussion of the experimental methods, procedures, and results were described in this paper.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2010년도 추계학술대회
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• pp.63-80
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• 2010

This paper describes the development of various lighting equipment adapting Ultra Constant Discharge Lamp that has newly been on commercial supply in the market. Meeting the required conditions of lighting equipment, various types of UCD Lamp equipment with excellent performances could be successfully developed. In order to provide a guideline for the economical lighting product selection, the analyzed data comparison between Hi-pressure Sodium Lamp which has been the most popular lamp for street lighting and UCD Lamp is provided. The conclusions of the study are made as follows; (1) The performance measurement result of UCD Lamp shows excellent Luminous Efficacy as 108Lm/W, daylight-like Color Rendering Index as 90Ra, and the best operating temperature range as $-50^{\circ}C{\sim}+85^{\circ}C$. Comparing to the Hi-pressure Sodium Lamp, UCD could be evaluated as much superior products. (2) In an assembled status with the lighting fixture (Type STB형-60W), UCD Lamp was tested OK for one hour duration at the temperature range form $-50^{\circ}C$ to $+85^{\circ}C$ and the humidity of 98%. The operation at the extremely low temperature can be an excellent feature to enable the export to the cold temperature regions such as Northern Europe and Russia and the specific applications for defense systems and special industry. (3) As UCD Lamp is a genuine Korea made product following Energy-saving and Eco-friendly policy, it should be appreciated as one of the best $CO^2$ reduction Green product.

• 한국항공우주학회지
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• 제35권2호
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• pp.101-106
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• 2007

인공위성 카메라 주반사경의 광학적 성능은 반사경과 반사경 지지부의 접착특성에 크게 영향을 받는다. 따라서 고성능의 주반사경을 설계하기 위해서는 접착제의 기계적 특성 규명이 필수적이다. 본 연구에서는 3종의 접착제를 선별하여 이에 대한 기계적 특성을 규명한다. 접착제의 탄성계수는 인장 시험을 통해 얻을 수 있다. 비선형 거동을 보이는 접착제의 경우 지수함수 형태로 곡선맞춤을 수행하여 응력-변형률 관계를 얻고, 선형거동을 보이는 접착제의 경우 선형 맞춤을 통해 탄성계수를 얻는다. 접착제의 작동 온도 범위내 8개 온도점을 선택하여 시험을 수행한다. 시험을 통해 탄성계수를 온도에 따른 함수로 표현하고, 이를 바탕으로 접착제의 특성에 대해 논의 한다.

• 한국태양에너지학회 논문집
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• 제37권2호
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• pp.35-45
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• 2017

The types of installation of the photovoltaic system applied to domestic residential buildings are classified as follows: Mounted modules with air circulation, semi-integrated modules with air duct behind, integrated modules with fully insulated back. In order to study generation characteristics of PV system, we verified the validity of interpretation program based on long-term measurement data of demonstration house installed in BAPV form and also analyzed the generation characteristics and performance of each installation type. The results are as follows. First, the RMSE of amount of generation and simulation according to annual daily insolation of demonstration system located in Daejeon was 0.98kWh and the range of relative error of monthly power generation was -5.8 to 3.1. Second, the average annual PR of mounted modules was 82%, semi-integrated modules 76.1% and integrated modules 71.9%. This differences were attributed to temperature loss. Third, the range of operating temperature of annual hourly photovoltaic modules was -6.5 to $61.0^{\circ}C$ for mounted modules, $-6.0{\sim}73.9^{\circ}C$ for semi-integrated modules and -5.5 to $88.9^{\circ}C$ for integrated modules. The temperature loss of each installation type was -14.0 to 16.1%, -13.8 to 21.9%, and -13.6 to 28.5%, respectively.