• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.739-746
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• 2010

The purposes of this study are 1) to develop an advanced chamber system within ${\pm}10%$ of air velocity at the particulate matter (PM) collection area, 2) to research theoretical characteristics of PM10 and PM2.5 samplers, 3) to assess the performance characteristics of PM10 and PM2.5 samplers through chamber experiments. The total six one-hour experiments were conducted using the cornstarch with an mass median aerodynamic diameter (MMAD) of $20\;{\mu}m$ and an geometric standard deviation of 2.0 at the two different air velocity conditions of 0.67 m/s and 2.15 m/s in the chamber. The aerosol samplers used in the present study are one APM PM10 and one PM2.5 samplers accordance with the US federal reference methods and specially designed three mini-volume aerosol samplers (two for PM10 and one for PM2.5). The overall results indicate that PM10 and PM2.5 mini-volume samplers need correction factors of 0.25 and 0.39 respectively when APM PM samplers considered as reference samplers and there is significant difference between two mini-volume aerosol samplers when a two-way analysis of variance is tested using the measured PM10 mass concentrations. The PM10 and PM2.5 samplers with the cutpoints and slopes (PM10: $10{\pm}0.5\;{\mu}m$ and $1.5{\pm}0.1$, PM2.5: $2.5{\pm}0.2\;{\mu}m$ and $1.3{\pm}0.03$) theoretically collect the ranges of 86~114% and 64~152% considering the cornstarch characteristics used in this research. Furthermore, the calculated mass concentrations of PM samplers are higher than the ideal mass concentrations when the airborne MMADs for the cornstarch used are smaller than the cutpoints of PM samplers and the PM samplers collected less PM in another case. The chamber experiment also showed that PM10 and PM2.5 samplers had the bigger collection ranges of 37~158% and 55~149% than the theocratical calculated mass concentration ranges and the relatively similar mass concentration ranges were measured at the air velocity of 2.15 m/s comparing with the 0.67 m/s.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.5 s.335
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• pp.31-38
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• 2005

The architecture and the implementation details of a UTMI(USB2.0 Transceiver Macrocell Interface) compatible USB2.0 transceiver chip were presented. To confirm the validation of the incoming data in noisy channel environment, a squelch state detector and a current mode Schmitt-trigger circuit were proposed. A current mode output driver to transmit 480Mbps data on the USB cable was designed and an on-die termination(ODT) which is controlled by a replica bias circuit was presented. In the USB system using plesiochronous clocking, to compensate for the frequency difference between a transmitter and a receiver, a synchronizer using clock data recovery circuit and FIFO was designed. The USB cable was modeled as the lossy transmission line model(W model) for circuit simulation by using a network analyzer measurements. The USB2.0 PHY chip was implemented by using 0.25um CMOS process and test results were presented. The core area excluding the IO pads was $0.91{\times}1.82mm^2$. The power consumptions at the supply voltage of 2.5V were 245mW and 150mW for high-speed and full-speed operations, respectively.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.347-353
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• 2002

A structure of a glass electrode-type pH sensor for measuring any concentration of $H^+$ in an aqueous solution was embodied with bulk micromachining technology. Two open well structures were formed, and a reference electrode was secured by the Ag/AgCl thin film in the sloped side of the etched structure. A sensitive membrane of an indicator electrode for generating a potential by an exchange reaction to $H^+$ was made with a glass containing Na 20% or more finely so that its thickness might be $100{\mu}m$ or so, and then it was bonded to one pyramidal structure. A liquid junction for a current path was formed by filling an agar in the anisotropically etched part of the Si wafer, which had a size of $50{\mu}m{\times}50{\mu}m$, and then bonded it to the other. After complete fabrication of each part, it was filled with a 2M KCl reference solution and encapsulated the sensor structure with a cold expoxy. The potential value of fabricated pH sensor was about 90mV/pH in the standard pH solutions.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.57-64
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• 1986

This paper described an improved technical method required for proper evaluation of personnel exposures by means of the photographic dosimeter developed by KAERI in lower gamma or X-ray energy regions, with which response of the dosimeter varies significantly. With calibration of the dosimeter in the energy range from 30 to 300 keV, the beam spectrum was carefully selected and specified it adequately. The absorber combinations and absorber thickness used to obtain the specified X-ray spectra from a constant potential X-ray machine were determined theoretically and also experimentally. A correlation between the density and exposure for the four separate energies, such as $49\;keV_{eff},\;154\;keV_{eff}\;250\;keV_{eff}\;and\;662\;keV$, is experimentally determined. As a result, it can be directly evaluated the exposure from the measured response of dosimeter.

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.275-283
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• 1995

PERALS(Photon Electron Rejecting Alpha Liquid Scintillation) spectrometry coupled with solvent extraction method has been set up for the analysis of $^{222}Rn\;and\;^{226}Ra$ in the groundwater. This analytical method offers low background, better energy resolution and lower quenching problem than the other techniques. By the analysis of NIST SRM 4966 $^{226}Ra$ standard, the analytical accuracy and precision were found to be 3% and 1%, respectively, and the relative standard deviation of the recovery of Rn extraction between pH2 and pH10 was 7%. Detection limits of $^{222}Rn$ and $^{226}Ra$ for 10 hours counting were counted to be $0.42 pCi/{\iota}\;and\;0.016 pCi/{\iota}$, respectively. For the test analysis of $^{222}Rn\;and\;^{226}Ra$ in the graundwater, hot spring water samples of 17 regions were analyzed. The concentration of $^{222}Rn$ were in the range of $90{\sim}5200pCi/{\iota}$ and average value was $1470pCi/{\iota}\;^{226}Ra$ concentration showed a peak value of $97.9pCi/{\iota}$ in a Kangwon region, but the average value was $1.14pCi/{\iota}$ except that region.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.22-27
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• 1997

특정 제품이 가진 "감성 이미지"란 그 제품의기능과 함께 제품의 감각적 요소 그리고 사용자가 제품에 대해 가진 개념적인 사고 과정의 산물이다. 감성이미지의 국제 비교 연구는 사용자가 특정 제품에 대해 가지고 있는 이미지를 국가나 문화의 맥락 속에서 상호 비교 평가하여, 각 국가나 사회집단을 특팅지울 수 있는 문화적 감성 요소를 추출하고자 하는 것이다. 즉, 각 국가의 생활문화 속에서 사용자들이 제품에 대해 가지는 감성이미지를 계량적으로 규명하고 비교 평가하며, 이 정보를 기초로 각국의 문화와 정서에 적합한 제품 디자인의 모형을 제시하는데 본 연구의 목적이 있다. 구체적인 연구방법은 우선, 자동차 제품을 중심으로 '제품 이미지'를 나타내는 '언어 이미지'스케일을 각 문화 집단 별로 구성한다. 이 제품 이미지에 대비하여, 감성적 요소로 선정된 표준 색채 스케일을 중심으로 나타난 집단의 '이미지'를 상호 비교 평가한다. 이 경우, 각 국가별 집단에서 특징적으로 나타나는 제품의 주요 특성이 감성 이미지로 표현되는 색채 이미지에 어떻게 반영되는가를 상호 비교한다. 이 연구에서는 특정 지역의 사람들이 제품에 적용하는 감성이미지는 색채나 기타 감성 요소에 대한 선호의 문제가 아니라 그 집단의 사람들이 그 제품을 통해 표현하고자 하는 사회적 표상의 반영이라는 것을 보여준다. 따라서, 제품의 이미지가 각 국가별로 공유되는 감성 이미지로 변환되기 위해서는 동일한 의미나 상징성을 지닌 감성 요소를 활용하여 그 제품의 이미지를 포장할 수 있는 방법을 적용하는것이다. 본 연구에서는 각 문화 집단들이 특정 제품에 대해 가지고 있는 사회적 표상(social representation) 체계를 색채스케일에서 나타난 감성 이미지를 통해 구체화하는 것이다.로서는 방전효율의 저하가 없는 양호한 성능을 보였으며, SC의 시범 작동시험을 실차(소나타 1800cc)에 장착하여 수행한 결과 20회 이상의 연속시동에서도 아무런 문제점 없이 잘 동작하였다.되는 데이타를 입력한후 마우스로 원하는 작업의 메뉴를 선택하면 된다. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the le

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.29-37
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• 2008

With the rapid development of display technology as well as the diversity of display, image quality assessment plays an important role in display color reproduction. The image quality has described by objective evaluation based on the physical measured data, such as contrast ratio, color reproduction range, color temperature, and gamma characteristics, etc., however, the final judgement is achieved by perceptual quality assessment of observers. Therefore, it is necessary to investigate the relationship between physical performance of display and perceptual image quality. Thus, in order to evaluate objectively the color reproduction characteristics of two mobile displays, TFT-LCD and AMOLED, we measured the darkroom contrast ratio of full screen, luminance and color temperature of full-screen white, full-screen gray and color linearity, tone reproduction of color scales for each RGB primary, and color reproduction range. Then the pair-wise comparison is implemented for image experts and naive observers not only to judge their preference on principal evaluation attributes but also to subjectively describe perceived image quality. Through two evaluation processes, we derived the objective bases that can prove the results of subjective image quality assessment by interconnecting physical factors that have influence on observers' preference judgements. Finally, this paper provided important information for improving the image quality and increasing preference from an observer's point of view.

• Korean Journal of Remote Sensing
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• v.24 no.6
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• pp.559-569
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• 2008

The Geostationary Ocean Color Imager (GOCI) on board the Communication Ocean Meteorological Satellite (COMS), the first geostationary ocean color sensor, requires accurate atmospheric correction since its eight bands are also affected by atmospheric constituents such as gases, molecules and atmospheric aerosols. Unlike gases and molecules in the atmosphere, aerosols can interact with sunlight by complex scattering and absorption properties. For the purpose of qualified ocean remote sensing, understanding of aerosol-radiation interactions is needed. In this study, we show micro-physical and optical properties of aerosols using the Optical Property of Aerosol and Cloud (OPAC) aerosol models. Aerosol optical properties, then, were used to analysis the relationship between theoretical satellite measured radiation from radiative transfer calculations and aerosol optical thickness (AOT) under various environments (aerosol type and loadings). It is found that the choice of aerosol type makes little different in AOT retrieval for AOT<0.2. Otherwise AOT differences between true and retrieved increase as AOT increases. Furthermore, the differences between the AOT and angstrom exponent from standard algorithms and this study, and the comparison with ground based sunphotometer observations are investigated. Over the northeast Asian region, these comparisons suggest that spatially averaged mean AOT retrieved from this study is much better than from standard ocean color algorithm. Finally, these results will be useful for aerosol retrieval or atmospheric correction of COMS/GOCI data processing.

• Journal of Advanced Technology Convergence
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• v.2 no.4
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• pp.13-19
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• 2023

Following the signing of the Paris Agreement on Climate Change (UNFCCC, 2015), the world is expanding greenhouse gas reduction activities through comprehensive participation that includes not only developed countries but also developing countries. Major countries around the world are placing high expectations on the effectiveness of total carbon emissions regulation through the carbon emissions market. However, in order to obtain carbon credits, third-party verification is required based on quantitative carbon reduction data. Accordingly, in this paper, we developed an AIoT high-efficiency street light for carbon emissions and conducted a performance analysis study to measure the luminous efficiency of the lighting fixture. To obtain carbon emissions rights, we used high-efficiency LED PKG, developed our own high-voltage PFC, and developed high-efficiency lighting fixtures capable of communication. For communication, the 2.4GHz LoRa method was adopted between the lighting fixture and the gateway. Lens design was conducted through simulation of Korea Expressway Corporation's standard streetlight types A, B, and C. The performance of the streetlight was verified as being more efficient than other existing products through the measurement of luminous efficiency by an accredited rating agency, and it is expected that carbon emissions rights will be obtained by reducing electrical energy through this.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.61-81
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• 2024

eCall system assists traffic accident victims by connecting emergency rescue institutions with accurate accident information, helping them to identify the on-site situation in the event of a traffic accident. The purpose of this paper is to develop a Korean eCall system that reflects the requirements of domestic emergency rescue institutions and to analyze the expected effects through an integrated demonstration. The results of an integrated demonstration indicated that the communication success rate between the eCall IVS and the call center was 99.25%, and the average location information error was 1.2 m. In particular, it has been confirmed that the average location information error is less than 21.6 meters, as assessed by the Korea Communications Commission when evaluating the accuracy of domestic emergency rescue location information. When the eCall system was introduced, it was confirmed that the time from traffic accidents to hospital arrival could be shortened by 3 m 38 s for highways and 1 m 22 s for general roads. By it to traffic deaths from 2005 to 2022, it was analyzed that the number of fatalities decreased by 82,662, resulting in a reduction of approximately social costs.