• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.585-591
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• 2000

The wavelet transform is the most recent technique for processing signals with time-varying spectra. In this paper, the wavelet transform is utilized to improved the assessment and multi-resolution analysis of acoustic emission signals generating in partial discharge. This paper especially deals with the assessment of process statistical parameter using the features extracted from the wavelet coefficients of measured acoustic emission signals in case of applied voltage 20[kv]. Since the parameter assessment using all wavelet coefficients will often turn out leads to inefficient or inaccurate results, we selected that level-3 stage of multi decomposition in discrete wavelet transform. We applied FIR(Finite Impulse Response)digital filter algorithm in discrete to suppression for random noise. The white noise be included high frequency component denoised as decomposition of discrete wavelet transform level-3. We make use of the feature extraction parameter namely, maximum value of acoustic emission signal, average value, dispersion, skewness, kurtosis, etc. The effectiveness of this new method has been verified on ability a diagnosis transformer go through feature extraction in stage of acting(the early period, the last period) .

• Journal of the Korean Wood Science and Technology
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• 제35권5호
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• pp.24-37
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• 2007

The Korean Ministry of Environment started controlling indoor air quality (IAQ) in 2004 through the introduction of a law regulating the use of pollutant emitting building materials. The use of materials with formaldehyde emission levels above $1.25 mg/m^2{\cdot}h$ (JIS A 1901, small chamber method) has been prohibited. This level is equivalent to the $E_2$ grade ($>5.0mg/{\ell}$) of the desiccator method (JIS A 1460). However, the $20{\ell}$ small chamber method requires a 7-day test time to obtain the formaldehyde and volatile organic compound (VOC) emission results from solid building interior materials. As a approach to significantly reduce the test time, the field and laboratory emission cell (FLEC) has been proposed in Europe with a total test time less than one hour. This paper assesses the reproducibility of testing formaldehyde and TVOC emissions from wood-based composites such as medium density fiberboard (MDF), laminate flooring, and engineered flooring using three methods: desiccator, perforator and FLEC. According to the desiccator and perforator standards, the formaldehyde emission level of each flooring was ${\le}E_1$ grade. The formaldehyde emission of MDF was $3.48 mg/{\ell}$ by the desiccator method and 8.57 g/100 g by the perforator method. To determine the formaldehyde emission, the peak areas of each wood-based composite were calculated from aldehyde chromatograms obtained using the FLEC method. Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and benzaldehyde were detected as aldehyde compounds. The experimental results indicated that MDF emitted chloroform, benzene, trichloroethylene, toluene, ethylbenzene, m,p-xy-lene, styrene, and o-xylene. MDF emitted significantly greater amounts of VOCs than the floorings did.

• 자원ㆍ환경경제연구
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• 제28권1호
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• pp.1-37
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• 2019

본 연구는 152개 국가의 불균형 패널 자료를 활용하여 1980~2013년 기간의 국가별 소득수준에 따른 1인당 $CO_2$ 배출 수렴 현상을 시그마 수렴 모형과 베타 수렴 모형을 통해 분석하였다. 절대적 베타 수렴과 시그마 수렴 현상은 $CO_2$ 배출 감축을 위한 국가별 정책 상황에 따라 소득 그룹별로, 기간별로 상이하게 나타났다. 조건부 베타 수렴 분석 결과, 고소득 국가에서 1인당 소득의 증가가 1인당 $CO_2$ 배출량 수렴에 기여하였으며 제도의 수준과 기술의 수준이 높을수록 소득의 증가가 배출량 수렴 속도를 더 빠르게 감소시키는 것으로 나타났다. 중소득 국가는 1인당 소득의 증가가 1인당 $CO_2$ 배출량 수렴에 영향을 미쳤으나, 제도의 수준은 유의미하지 않게 나타났다. 반면 중소득 국가와 저소득 국가의 기술 수준 향상은 1인당 $CO_2$ 배출량 수렴 속도를 늦추는 것으로 나타나 배출량 증가에 기여하는 것으로 분석되었다.

• 한국환경과학회지
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• 제28권4호
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• pp.455-464
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• 2019

BAT-AEL(Best Available Techniques Associate Emission Level) is the basis for establishing permissible emission standards for the workplace. Therefore, it is necessary to formulate a regulated BAT-AEL setting methodology that is generally applicable to all relevant industries. For the BAT-AEL settings, various factors should be considered such as the pollutants item, whether the workplace is subject to integrated pollution prevention and control, whether BAT is applicable, the basic data type, the emission classification system, and the suitability of the collected data. Among these factors, it is the most important factor to establish the classification system for the emitting facilities such that the emission characteristics of an industrial facility and its pollutants can be effectively reflected. Furthermore the target of the survey workplace should adhere to the BAT guidelines, even if it is a workplace that is subject to an the integrated environmental system. Certified data (SEMS, TMS, cleanSYS, WEMS, etc.) can be used to prioritize the classification system for the emission facility and the emission levels of pollutants. However, the self-measured data, daily logs, and questionnaire data from the workplace can also be used upon agreement of the relevant TWG. The collected data should only be used only when the facility is operating normally. Data that have been determined to be outliers or inappropriate validation methods should also be excluded. The BAT-AEL can be establish by adhering to the following procedure: 1) investigate all relevant workplaces with in the industry, 2)select workplaces for integrated management, 3)Identify BAT application, 4)identify whether BAT is generally applicable, 5)establish a classification system for emitting facilities, 6)collection available data, 7)verify conformity, 8)remove of outliers, 9)prepare the BAT-AEL draft, 10)deliberate, and 11) perform the confirmation procedure.

• 자원ㆍ환경경제연구
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• 제22권3호
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• pp.437-457
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• 2013

본 연구는 환경쿠즈네츠 곡선 가설이 제시하는 환경오염물질의 배출량이 증가하다가 일정 소득 이상이 되면 감소하는 현상에 대해, 그 원인을 미시적인 변수인 인식수준과 연관 지어 설명하는데 목적이 있다. 인식수준은 오염물질의 영향이 지역적(이산화황)이냐 아니면 지구적(이산화탄소)이냐에 따라, 다르게 형성되며, 이에 따라 배출량 변화에 미치는 영향도 상이하게 나타날 수 있음을 확인하였다. 이를 실증적으로 살펴보면, 오염물질 영향과 인식수준 간에 발생하는 상이한 반응 작용을 간과한 경우, 환경오염물질 배출량이 증가하다가 감소하는 전환점이 과소 혹은 과대 추정될 수 있음을 확인하였다. 이와 더불어 오염물질의 영향이 지역적이냐 지구적이냐에 따라, 인식수준에 미치는 영향에 차이가 발생하여, 지역적 오염물질이 글로벌 오염물질에 비해 더 낮은 소득 수준에서 배출량이 증가에서 감소로 전환되는 것을 확인하였다. 이러한 결과로부터 도출할 수 있는 정책적 시사점은, 지역적 오염물질에 비해 글로벌 오염물질인 이산화탄소의 저감을 위해서는, 교육과 홍보 등 정부의 적극적 노력이 요구되며, 규제 및 저탄소 기술 개발과 동일한 수준의 국민 의식제고를 위한 노력과 자원 투자가 필요하다는 점이다.

• 전기학회논문지
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• 제59권9호
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• pp.1507-1513
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• 2010

The $CO_2$ emission can be decreased due to freedom of generator maintenance scheduling(GMS). This paper proposes assessment of $CO_2$ emission considering generator maintenance scheduling(GMS) and evaluates effect of the GMS on $CO_2$ emission. And also, this paper assesses the $CO_2$ emission and the probabilistic production cost simulation of nuclear and thermal power generators considering operation of hydro and pumped generator. The minimum reliability criterion level satisfied production cost minimization function model is used in this paper. The practicality and effectiveness of the proposed approach are demonstrated by simulation studies for a real size power system in Korea in 2010.

• 한국대기환경학회지
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• 제1권1호
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• pp.83-92
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• 1985

In odrder to survey the emission level of air pollutants from diesel vehicles, was measured CO, HC, NOx and smoke of 4 types of domestic-use diesel engines under various conditions. The emission of CO, HC and NOx tested by 6-Mode test method and smoke emission by full load test met the permissible vehicle emission standard. Pollutant emission rates of diesel engines were different according to engine operating conditions, that is, engine load and engine speed. Generally, CO and HC was emitted more at low load and NOx at high load but the trend was quite different by the type of engines. In exhaust gas, $NO_2$ portion of NOx emission was high, specially at low speed and low load. The correlation equation between CLD(NOx) and NDIR(NO) method of nitrogen of nitrogen oxides analysis was y = 1.10x - 3.48 (y: CLD method) as a result of 6-mode test.

• 천문학회보
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• 제42권2호
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• pp.81.2-81.2
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• 2017

Polarized mid-infrared emission from polycyclic aromatic hydrocarbons (PAHs) can provide a crucial test of basic physics of alignment of nanoparticles and opens a potential new window into studying magnetic fields. In this talk, I will present a new model of polarized PAH emission that takes into account the effect of PAH alignment with the magnetic field due to resonance paramagnetic relaxation. I will then present our predictions for the polarization level of the strong PAH emission features from the interstellar medium. I will present the first detection of polarization of PAH emission at 11.3micron which is consistent with our theoretical prediction. Finally, I will discuss important implications of this work for tracing magnetic fields via mid-IR PAH features and for constraining the polarization of anomalous microwave emission that is useful for the quest of CMB B-modes.

• 소음진동
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• 제6권6호
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• pp.843-849
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• 1996

Locations and emission characteristics of noise source of motor vehicles are great important factors to control the road traffic noise in effective ways. From results of this study on emission characteristics of engine and exhaust noise, we could find that every noise emission of different kind of vehicles has smilar pattern. The main emission locations of engine noise for the front of vehicle became the space between the road surface and bottom of the body and radiator grill, and for the side of vehicle became the space between the road surface and bottom nearby the front wheel. In case of exhaust noise of passenger-car and light truck, all the highest sound intensity level located near surface of road. But it is hard to conclude the height of noise source of driving vehicles with only results of this study. So further studies are needed to check the emission characteristics of noise.

• 한국도로학회논문집
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• 제17권3호
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• pp.125-132
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• 2015

PURPOSES : The present study aims to evaluate the added $CO_2$ emissions incurred from accelerating operation when to increase the speed up to the allowed level. METHODS : The methodology used are basically the relationship between emission rates and vehicle speeds or acceleration rate. These rates together are used to calculate the added $CO_2$ emissions incurred from accelerating operation. RESULTS : It was resulted that the all the emission rates are increasing proportionally to vehicle speeds or acceleration rates. Additionally, it was also resulted that allowable speeds increasing, the added emission rates are increasing rapidly. CONCLUSIONS : It may be concluded that if the allowable speed ranges are managed, $CO_2$ emissions during vehicle operation are much reduced. From this reason, it was found that the allowable speed during highway design and operation would be much necessary