• 공업화학
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• 제32권3호
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• pp.277-282
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• 2021

본 연구에서는 PF₆를 음이온으로 하며, 이미다졸리움 계열의 양이온을 변화시키면서 2종의 소수성을 띠는 이온성 액체 전해질을 합성하였다. 합성한 이온성 액체는 1-benzyl-3-butylimidazolium hexafluorophosphate [BzBIM]PF₆와 1-pentyl-3-butylimidazolium hexafluorophosphate [PBIM]PF₆이며 이들 각각의 구조는 푸에리에 변환 적외선 분광기와 핵자기공명 분광기를 이용하여 분석하였다. 이와 함께, 합성한 이온성 액체 전해질의 물리적(점도, 이온전도도, 열적 안정성) 및 전기화학적 특성을 조사하고 비교 분석하였다. 그 결과, [BzBIM]PF₆의 경우 [PBIM]PF₆와 다르게 이미다졸리움 양이온에 π-π 분자 간 결합이 강하게 존재하는 벤질링 기능기를 가지고 있어서 열적 및 전기화학적 특성에서 더 우세한 안정성을 보여주었다.

• 대한건축학회논문집:계획계
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• 제35권11호
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• pp.25-34
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• 2019

It is important to design windows in a reasonable way considering the performance characteristics of the elements of the window rather than just to increase the thermal energy performance of the window. In this study, the Heat-transfer Coefficient as insulation performance of the windows and together with the grade of the glass's SHGC (Solar Heat Gain Coefficient) were analyzed to relate to the energy efficiency performance of the building by azimuth angle. Based on this basic study, the Heat-transfer Coefficient of windows and the SHGC rating of glass were applied to the unit plan of apartment building, and the Heating and Cooling Demand were analyzed by azimuth angle. Apartment plan types were divided into 2 types of Non-extension and extension of balcony. The designPH analysis data derived from the variant of the Heat-transfer Coefficient and SHGC, were put into PHPP(Passive House Planning Package) to analyze precisely the energy efficiency(Heating and Cooling Demands) of the building by azimuth angle. In addition, assuming the 'ㅁ' shape layout, energy efficiency performance and potential of PV Panel installation also were analyzed by floors and azimuth angle, reflecting the shading effects by surrounding buildings. As the results of the study, the effect of Heat Gain by SHGC was greater than Heat Loss due to the Heat-transfer Coefficient. So it is more effective to increase SHGC to satisfy the same Heating Demand, and increasing SHGC made possible to design windows with low Heat-transfer Coefficient. It was also revealed that the difference in annual Heating and Cooling Demands between the low, mid and high floor households is significantly high. In addition to it, the installation of PV Panel in the form of a shading canopy over the window reduces the Cooling Load while at the same time producing electricity, and also confirmed that absolute thermal energy efficiency could not be maximized without controlling the thermal bridge and ventilation problems as important heat loss factors.

• 한국전자파학회논문지
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• 제12권6호
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• pp.994-1001
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• 2001

본 논문에서는 이동 통신 시스템에서의 PIC기법으로 간섭을 제거하여 개선된 SIR을 기반으로 하는 전력 제어 방식을 제안한다. 일반적으로 전력 제어는 SIR을 기반으로 하는 방식이 사용되고 있다. 그러나 이 방식은 시스템의 안정성을 떨어뜨리는 Positive Feedback 현상을 발생시킨다. 따라서 제안된 전력 제어 기법은 SIR의 변수인 간섭신호를 감소시켜 개선된 SIR을 기반으로 하는 전력제어를 수행하여 시스템의 안정화를 도모하였다. 또한 이동국에서 기존의 Up-Down전력 명령대신 Up-Maintain-Down기법을 이용하여 성능을 향상시켰다. 새로운 전력 제어 기법인 개선된 SIR방식과 기존의 방식을 모의 실험을 통하여 비교, 제안된 시스템의 성능 개선을 확인했다.

• KIEAE Journal
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• 제12권2호
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• pp.111-116
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• 2012

Faced with the international issue of environmental problems from global warming and energy consumption, the Korean Government has made many efforts on reducing energy and $CO_2$ emission under the motto of "Low-Carbon Green Growth". In order to reduce energy in the building sector, severe design standards and regulations on saving energy in new buildings have been established. Now, it is necessary to focus on deteriorated buildings where applications of energy saving designs and techniques have been insufficient, for maximizing energy saving in the building sector. Specially, it is very important to reduce energy through the remodeling process at deteriorated school buildings which were built over 20 years ago and sharply changed into the excessive energy consumption structure from new educational curricula. Thus, this paper examined the effects of potential factors to reduce energy at deteriorated elementary school buildings using the energy simulation on the Visual DOE 4.0 program. Among applied factors of insulations, southern louver, window's SHGC, indoor setup temperature, and system efficiency, all factors except window's SHGC turned out contribute to reduce energy at the deteriorated elementary school buildings, compared with the baseline energy performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2170-2172
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• 1999

A low energy large aperture(LELA) pulsed electron beam generator of a cold cathode type has been developed for environmental applications, for example, waste water cleaning, flue gas cleaning, and pasteurization etc. The operational principle is based on the emission of secondary electrons from cold cathode when ions in the plasma hit the cathode, which are accelerated toward exit window by the gradient of an electric potential. We have fabricated the LELA electron beam generator with the peak energy of 200keV and beam diameter of 200mm and obtained the large aperture electron beam in air. The electron beam current density has been investigated as a function of glow discharge current, accelerating voltage and radial distribution in front of the exit window foil. The plasma density and electron temperature have been measured in order to confirm the relation with the electron beam current density. We are going to upgrade the LELA electron beam generator in the electron energy, electron beam current and stability of operation for various applications.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.148-157
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• 1998

This study presents test results of a residential window air-conditioner using R22 and two potential alternative refrigerants, R407C and R410B. A series of performance tests has been carried out for the basic and liquid-suction heat exchange cycles in a psychometric calorimeter test facility. For R407C, the same rotary compressor was used as in the R22 system. However, compressor for the R410B system was modified to provide the similar cooling capacity. The evaporator circuit was changed to get a counter-cross flow heat exchanger to take advantage of zeotropic mixture's temperature glide, and liquid-suction heat exchange cycle was also considered to improve the system performance. Test results were compared with those for the basic R22 system. The modified system with a liquid-suction heat exchanger increased cooling capacity and energy efficiency by up to 5%.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.133-141
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• 2006

최근 많은 착용형 컴퓨터가 개발되었지만, 아직도 입력 및 출력 관점에서 보면 사용자 인터페이스에 많은 문제를 가지고 있다. 본 논문에서는 EOG 감지 회로와 마커 인식에 기반한 착용형 사용자 인터페이스를 제안한다. 제안된 사용자 인터페이스에서 EOG 감지 회로는 지시 장치로 사용되는데, 눈 주위의 전위차를 감지함으로써 눈동자의 움직임을 추적한다. 사용자가 다루고자 하는 객체는 사람이 인지 가능한 마커로 표시되며 마커 인식 시스템은 카메라 영상으로부터 마커를 검출하고 인식한다. 마커가 인식되면 해당하는 객체에 대한 속성창과 마커 창이 HMD에 디스플레이되고 사용자는 원하는 속성이나 메소드를 선택함으로써 객체를 다루게 된다. EOG 감지 회로와 마커 인식 시스템을 이용함으로써 사용자는 착용형 컴퓨팅 환경에서 눈동자의 움직임만으로 객체의 조작을 손쉽게 수행할 수 있다.

• 한국의학물리학회지:의학물리
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• 제23권4호
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• pp.229-233
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• 2012

광자선 출력측정시 업무 효율을 높이기 위한 소형 물팬톰(듀얼윈도우 팬톰)을 개발하였다. 이 팬톰은 고에너지 광자선의 출력측정뿐만아니라 선질지표의 결정에 적합하다. 이 팬톰은 두개의 창을 가지고 있으며 독립된 두 축에 의해 회전할 수 있도록 제작되어있다. 이 때 두 축은 전리함 이동 없이 조직팬톰선량비와 깊이선량율비를 결정하기 위한 것이다. 코발트조사기와 선형가속기의 고에너지 광자선을 이용하여 팬톰을 평가하였으며, 기준값과 비교할 때 Co-60의 경우 0.2% 그리고 가속기 x-선에 대해 1.4% 이내로 일치하였다. 이 팬톰은 발생 가능한 인적오차를 방지할 수 있기 때문에 일상의 출력측정에 매우 실용적이라고 본다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.86-89
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• 1995

A clinically oriented 32 channel Electroencephalogram (EEG) and evoked potential (EP) mapping system has been developed. The EEG and EP signals acquired from 32-channel electrodes are amplified by the pre-amplifier located near patient and are then tither amplified by main amplifier. An automatic artifact rejection scheme is employed using a neural network by which examination time is reduced substantially. Auditary and visual stimuli are used for the evoked potential mapping. A user-friendly graphical interface based on the Microsoft Window 3.1 is developed for the operation of the system. Statistical databases for the poop and individual comparisons are also included to support statistically based diagnosis.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.294-297
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• 2002

For the quality control procedure of diagnostic x ray units, a method for simultaneous measurement of air kerma, half value layer and tube potential was developed utilizing a computed radiography system for intraoral radiography and film badge case. The response of average pixel values under the windows were calibrated by x rays generated at tube potentials from 40 to 140 kV with filtration from 1.5 to 3.7 mmAl. The calibration curves for half value layer and tube potential were derived as functions of attenuation factors by the 1.4 mmAl filter and the 0.2 mmCu filter. The energy dependency of the open window response was corrected by the calibration factor as a function of the attenuation factor by the 1.4 mmAl filter. The uncertainty of the estimated half value layer, tube potential and air kerma were 0.2 mmAl, 3.6 % and 5 %, respectively. It was thus suggested that this system could be applied to quality control program to detect the variation of working condition of x ray units in clinical use.