본 연구의 목적은 실험으로 6 MV X-선 빔의 등가에너지를 결정하는 데 있다. 6 MV X-선 빔에 대한 납의 반가층은 전리함을 사용하여 측정하였다. 선감쇠계수는 측정된 반가층을 사용하여 계산하였다. 그리고 질량감쇠계수는 납의 밀도로 선감쇠계수를 나누어 얻었다. 얻어진 질량감쇠계수의 등가에너지는 미국표준기술연구소에서 주어진 납의 광자에너지 대 질량감쇠계수 자료를 사용하여 결정하였다. 그 결과로서, 6 MV X-선 빔에 대한 등가에너지는 1.61 MeV로 결정되었다. 이 등가에너지는 Reft가 보고한 것 보다 약 30% 낮게 결정되었다. 그 원인은 납 감쇠기 사이의 공기공동의 존재에 기인한 것으로 추정된다.

Interplanetary scintillation-driven (IPS-driven) ENLIL model was jointly developed by University of California, San Diego (UCSD) and National Aeronaucics and Space Administration/Goddard Space Flight Center (NASA/GSFC). The model has been in operation by Korean Space Weather Cetner (KSWC) since 2014. IPS-driven ENLIL model has a variety of ambient solar wind parameters and the results of the model depend on the combination of these parameters. We have conducted researches to determine the best combination of parameters to improve the performance of the IPS-driven ENLIL model. The model results with input of 1,440 combinations of parameters are compared with the Advanced Composition Explorer (ACE) observation data. In this way, the top 10 parameter sets showing best performance were determined. Finally, the characteristics of the parameter sets were analyzed and application of the results to IPS-driven ENLIL model was discussed.

우리나라는 2030년 까지 모든 경제분야에 걸쳐 온실가스 배출을 약 37% 감축할 계획을 UNFCCC에 제출하였다. 이에 따라 온실가스 감축목표를 설정하고 부문별･업종별 배출권 할당량을 결정하고 있다. 따라서 보다 정확한 온실가스 배출량을 산정하는 것이 중요하며 현재는 배출활동별 온실가스 배출량 세부산정방법과 기준을 Tier 1, 2, 3, 4로 마련하여 관리하고 있다. 활동자료와 배출계수로 계산하는 Tier 1~3 기준에는 화석탄소함량(FCF)을 적용하여 폐기물에 포함된 바이오매스의 비율이 제외될 수 있는 반면, 소각시설에서 발생하는 배출가스 중의 온실가스를 직접적으로 측정하는 Tier 4(연속측정법)에서는 총 CO2만 측정 가능하기 때문에 온실가스 중의 바이오매스량을 제외하기 위해서는 화석연료 기원물질에 의한 배출량과 바이오매스 기원물질에 의한 배출량 구분이 필수적이다. 따라서 본 연구에서는 생활폐기물 소각시설과 사업장폐기물 소각시설 각각에서 연소 후 배출되는 가스를 가스샘플링장치를 이용하여 포집하였으며, 포집한 가스성분과 CO2 중의 바이오매스 기원물질량을 확인하였다. 기체시료 중의 바이오매스량을 측정분석하기 위해서 탄소동위원소를 이용한 가속기 질량분석기(Accelerator Mass Spectrometry)를 이용하였으며 보다 명확한 온실가스배출량 산정을 위한 기초자료로 활용하고자 한다.

In this study, the recycling processes of construction and demolition waste (C&D waste) were analyzed, and its national recycling rate was determined using material flow analysis (MFA). Available statistical data provided by Ministry of Environment and Korea Environment Corporation were used for the MFA study. The collected data were carefully examined and validated by field investigations. System boundary for MFA covered from waste generation from construction sites to final disposal in 2013. The field investigation showed that recycled aggregate is produced through mechanical shredding, separation, and screening processes of C&D waste. The production efficiency (or process yield) was estimated to be approximately 81.2% on average. The foreign materials in the waste accounted for 18.8% by weight. The separated impurities were sent to recycling facilities, incineration facilities, or landfill sites, depending on the physicochemical characteristics. Efficiency of recycling facilities and the statistical data were integrated to estimate the national actual recycling rate, which turned out to be 87.7% in 2013. Approximately 49.1% of the construction-related waste was recycled as recycled aggregate for concrete production and road base layer for asphalt pavement. Based on the result of MFA, there is 9.8% difference between the actual recycling rate in this study and reported recycling rate by national statistics. In the future, more various C&D waste treatment and disposal facilities, along with aggregate recycling facility, should be investigated to verify the actual recycling rate determined by this study. Statistical accuracy should be further refined through additional field investigations. Our findings can be applicable to development of recycling policies and best management practices for C&D waste streams.

A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.

A new algorithm for determining optimal accelerometer locations is proposed by using a frequency-domain Hankel matrix which is much simpler to construct than a time-domain Hankel matrix. The algorithm was examined through simulation studies by comparing the outcomes with those from other available methods. To compare and analyze the results from different methods, a dynamic analysis was carried out under seismic excitation and acceleration data were obtained at the selected optimal sensor locations. Vibrational amplitudes at the selected sensor locations were determined and those of all the other degrees of freedom were determined by using a spline function. MAC index of each method was calculated and compared to look at which method could determine more effective locations of accelerometers. The proposed frequency-domain Hankel matrix could determine reasonable selection of accelerometer locations compared with the others.

Backgrounds : Pomelo (Citrus grandis Osbeck) is the kind of citrus fruit which is Dicotyledoneae belongs to Rutaceae and special product in Jeju island. According to the previous researches, coumarin, eliocitrin, naringin are identified and these kinds of constituents revealed to be effective as anticancer, antioxidant, and antidiabetic. Until recently, there are many investigations about its functional properties were reported, but investigation about biological activities depend on extraction conditions are not sufficient. Methods and Results : 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was performed by the method of Blois with minor modification. After adding DPPH radical to each sample solutions, the mixtures were incubated in 30 minutes at aphotic place. Then, the degree of scavenging activity was recorded by microplate reader at 490 nm. The scavenging activity was expressed by RC50, which is the concentration of sample solution necessitated to scavenge 50% DPPH radical against negative control. For α-glucosidase inhibitory activity, the method using p-nitrophenyl-α-D-glucopyranoside (pNPG) was applied. To each samples, α-glucosidase and pNPG were mixed and incubated, consequently, Na2CO3 was added to terminate the reaction. Finally, absorbance was read at 450 nm. The same as DPPH radical scavenging activity, the inhibition was explicitly expressed by the amount of sample solution to inhibit 50% α-glucosidase, IC50. The 80% MeOH extract demonstrated the highest radical scavenging activity with 74.32±8.45 μg/ml. α-Glucosidase inhibitory activity was carried out to evaluate the inhibitory activity of sugar digestion and absorption and 60, 80% MeOH extract exhibited 416.35±11.07 μg/ml and 336.57±2.03 μg/ml, respectively. Conclusion : The DPPH radical scavenging and α-glucosidase inhibitory activity were evaluated in this study. The highest DPPH radical scavenging activity was seen in 80% Citrus grandis Osbeck MeOH extract, following 60% MeOH extract exhibited the second highest scavenging activity. Also, 80% MeOH extract showed 336.57±2.03 μg/ml, which was the highest α-glucosidase inhibition among all extracts.

최근 건설되는 특수교량에는 상시적인 유지관리 체계로서 계측시스템이 활발히 도입되고 있는 상황이다. 일반적으로 계측시스템 을 이용한 교량 유지관리 시에는 관리기준치를 설정하여 교량의 상태를 평가하게 되지만, 관리기준치 설정 기준과 방법이 없어 설계허용값에 근거하여 단순하게 설정되고 있는 실정이다. 기존의 방법으로 설정된 관리기준치를 적용할 경우 관리기준치 범위 내에서 발생된 이벤트, 이상 거동 및 점진적으로 발생하는 손상 등과 같은 교량의 상태변화를 파악하기에는 한계가 있다. 따라서, 본 연구에서는 기존의 절대치 관리에 있 어 관리기준치 설정의 문제점을 고찰하여 실무에 효과적으로 적용가능한 개선된 관리기준치 설정 및 운영방법을 도출하였다. 개선된 관리기 준치 설정을 위해 검벨분포를 사용한 확률론적 접근방법을 도입하여 재현빈도 50년, 100년의 기댓값에 대한 교량의 주의, 경고치를 산정하였 다. 본 연구에서의 관리기준치는 설계허용치 범위 내에서 발생하는 이상거동을 감지할 수 있도록 계측데이터와 계측데이터의 구간변화량에 대한 관리기준치를 각각 설정되었으며, 제안된 방법으로 산정된 관리기준치는 실측 데이터에 대입하여 비정상적인 데이터의 발생여부를 적절 하게 파악할 수 있다는 것을 확인하였다.

본 연구에서는 가뭄사상과 확률 가뭄심도를 결정하는 새로운 방법을 제안하였다. 강우자료로부터 가뭄사상을 추출하기 위해 연속이론과 누적 강우부족량을 동시에 고려하였다. 절단수준 이상의 강우사상이 발생할 경우, 그 때까지의 누적 강우부족량을 해갈할 수 있을 만큼의 강우량이 발 생하였는가를 확인하여 가뭄사상의 종료여부를 최종 결정하였다. 이와 같이 추출된 가뭄사상의 지속기간과 심도의 상호 의존성 구조를 파악하여 결합분포함수를 추정하기 위해 코플라 함수를 적용하였다. 또한 이변량 코플라 함수의 조건부 함수를 이용하여 가뭄의 특정 지속기간에 대한 가뭄 심도의 재현특성을 분석하였으며, 신뢰구간을 추정하여 이변량 빈도해석의 불확실성을 정량화하였다. 서울지점의 1909∼2015년 강수자료에 적용한 결과 과거 극한가뭄으로 판단되었던 가뭄사상은 대부분 최소 10년에서 최대 50년 정도의 재현기간을 갖는 반면 2013년 발생하여 현재까 지 지속되고 있는 2015년 가뭄은 현저히 높은 재현기간을 가지고 있는 것으로 나타났다. 이러한 연구 결과는 향후 가뭄대책을 마련하는 데 있어 빈도개념을 바탕으로 하는 신뢰성 있는 기준으로 활용할 수 있을 것으로 기대된다

식용 귀뚜라미를 고압증기멸균한 뒤 동결건조하였으며, 이를 분쇄하여 AL/PET/LLDPE film에 포장 후 25, 35 및 40℃에서 6개월 동안 저장하며 한 달 간격으로 품질변화를 측정하였다. 수분함량은 저장기간 중 모든 구에서 증가하 였으나, 저장 6개월 차에 저장온도별 유의적 차이는 없었다. 산가의 초기값은 1.83 mg KOH/g 이였으며, 저장 6개월 차에 25, 35 및 40℃ 저장구는 1.93, 2.04 및 2.15 mg KOH/g 으로 증가하였다. 지방산은 palmitic acid, oleic acid 및 linoleic acid가 24.79, 28.58 및 28.55 g/100 g으로 높은 함량 을 나타내었으며, palmitic acid 및 linoleic acid는 저장온도 별 증·감소의 경향이 뚜렷하지 않았으나, oleic acid는 저장 기간 중 감소하는 경향을 나타내었다. 일반세균 및 대장균 군은 저장기간 동안 검출되지 않았다. 관능검사의 경우 25 및 35℃ 저장구는 유의적 차이가 없으나, 40℃ 저장구는 유의적 차이를 나타내었다(p<0.05). 저장기간 중 품질에 영 향을 미치는 인자는 수분함량, 산가, oleic acid 및 flavor로 판단되었으며, 이들의 한계 기준을 각각 5%, 3 mg KOH/g, 26.5 g/100 g 및 6으로 설정하여 유통온도 25℃를 기준으로 VSLSF 프로그램으로 유통기한을 산출하였다. 수분함량, 산가, oleic acid 및 flavor의 유통기한을 산출한 결과 23, 61, 150 및 155개월이었으며, 유통기한이 가장 짧은 항목에 안전계수 0.8을 적용하여 18개월로 설정하였다. 이상의 결 과는 제조 후 25℃ 유통조건에서 18개월까지는 귀뚜라미 분말의 품질 안정성이 유지되는 것으로 판단되었다.

Impact factor for used in the load carrying capacity evaluation of bridges is varied depending on vehicle speed and bridge frequencies. So, it is hard to define its peak value since in the field test the truck speeds applied cannot cover all possible vehicle speeds and the speed per each vehicle loading test cannot remain constant consistently. Furthermore, the target bridges should be closed during field test, which leads to an inconvenient traffic flow. In this paper, a displacement-based response spectrum of bridges is considered to define the peak impact factor without conducting the standard vehicle loading test, while using a bridge operational traffic condition.

This study was conducted to develop a fast and efficient screening method to determine the quantity of fatty acid in peanut oil for high oleate breeding program. A total of 329 peanut samples were used in this study, 227 of which were considered in the calibration equation development and 102 were utilized for validation, using near infrared reflectance spectroscopy (NIRS). The NIRS equations for all the seven fatty acids had low standard error of calibration (SEC) values, while high R2 values of 0.983 and 0.991 were obtained for oleic and linoleic acids, respectively in the calibration equation. Furthermore, the predicted means of the two main fatty acids in the calibration equation were very similar to the means based on gas chromatography (GC) analysis, ranging from 36.7 to 77.1% for oleic acid and 7.1 to 42.7% for linoleic acid. Based on the standard error of prediction (SEP), bias values, and R 2 statistics, the NIRS fatty acid equations were accurately predicted the concentrations of oleic and linoleic acids of the validation sample set. These results suggest that NIRS equations of oleic and linoleic acid can be used as a rapid mass screening method for fatty acid content analysis in peanut breeding program.

대한민국 식품의약품안전처(식약처)는 포름알데하이드 분석법으로 2,4-dinitrophenylhydrazine (DNPH) 유도체화-고성능액체크로마토그래프법(HPLC)을 고시하고 있다. 본 연구는 고시법의 복잡한 시료 전처리 과정을 개선하여 화장품 분석에 편리하게 사용할 수 있는 유도체화법을 개발하고자 수행되었다. 전처리 법을 간단하게 하기 위하여 pH, 시간 및 온도 등 반응조건을 최적화하였다. 이 전처리법은 초산염 완충액(pH 5.0)을 사용한 검액의 pH 조정, 디클로로메탄을 사용한 액-액 분획 그리고 감압농축기를 사용한 증발건조와 같이 식약처 고시법의 복잡한 과정이 필요 없다. 유도체화 과정을 통하여 생성된 formaldehyde dinitrophenylhydrazone (formaldehyde-DNP)는 식약처의 시험방법을 약간 변형한 역상 HPLC법으로 분리하고 정량하였다. 2 ∼ 40 ppm 농도 범위의 표준액들을 가지고 수행한 검량선 작성 결과, 본 시험법은 상관계수 값 이 0.9999로 좋은 직선성을 보여주었다. 본 실험의 최소검출한계(LOD)와 최소정량한계(LOQ)는 각각 0.2 ppm과 0.5 ppm이었다. 또한 회수율 실험결과는 실험방법이 매우 정확하고 재현성이 높음을 보여주었다. 따라 서 본 연구에서 제안된 시험법은 화장품 중 포름알데하이드를 신속하게 분석하는데 적용될 수 있을 것이다.

The volatile flavor components of the fruit pulp and peel of orange (Citrus sinensis) and grapefruit (Citrus paradisi) were extracted by simultaneous distillation-extraction (SDE) using a solvent mixture of n-pentane and diethyl ether (1:1, v/v) and analyzed by gas chromatography-mass spectrometry (GC-MS). The total volatile flavor contents in the pulp and peel of orange were 120.55 and 4,510.81 mg/kg, respectively, while those in the pulp and peel of grapefruit were 195.60 and 4,223.68 mg/kg, respectively. The monoterpene limonene was identified as the major voltile flavor compound in both orange and grapefruit, exhibiting contents of 65.32 and 3,008.10 mg/kg in the pulp and peel of orange, respectively, and 105.00 and 1,870.24 mg/kg in the pulp and peel of grapefruit, respectively. Limonene, sabinene, α-pinene, β-myrcene, linalool, (Z)-limonene oxide, and (E)-limonene oxide were the main volatile flavor components of both orange and grapefruit. The distinctive component of orange was valencene, while grapefruit contained (E)-caryophyllene and nootkatone. δ-3-Carene, α-terpinolene, borneol, citronellyl acetate, piperitone, and β-copaene were detected in orange but not in grapefruit. Conversely, grapefruit contained β-pinene, α-terpinyl acetate, bicyclogermacrene, nootkatol, β-cubebene, and sesquisabinene, while orange did not. Phenylacetaldehyde, camphor, limona ketone and (Z)-caryophyllene were identified in the pulp of both fruits, while α-thujene, citronellal, citronellol, α-sinensal, γ-muurolene and germacrene D were detected in the peel of both fresh fruit samples.

The Intergovernmental Panel on Climate Change (IPCC) recommended the first order decay (FOD) model for estimating methane emissions from solid waste landfills. However, selecting appropriate parameter is a major challenge in methane emission modeling. The degradable organic carbon (DOC) and the fraction of degradable organic carbon which decomposes (DOCF) are the two primary parameters in the methane generation potential (L0). The DOC is the amount of organic carbon that can be decomposed by biochemical reactions in microorganisms. Chemical analysis methods are currently available to measure the DOC including using total organic carbon and element analysis methods. However, chemical analysis methods are not appropriate for determination of the DOC, which indicated that the DOC should be measured by biochemical tests. In addition, these methods should consider a fossil carbon content that needs a complex and high cost of analysis. The DOCF is an estimate of the fraction of carbon that is ultimately degraded and released from landfills. However, no methodology is provided for determination of the DOCF in landfills. Therefore, the purpose of this study was to suggest methodologies for the determination of DOC and DOCF in solid waste landfills. A biochemical methane potential (BMP) test could be used to calculate the DOC because the BMP represents an upper limit on the methane potential of a waste, which corresponds to a maximal amount of degraded organic carbon. The calculation was based on the assumption that the DOCF is 100%. In this study, two methodologies were suggested to determine the DOCF in landfills. The first one uses a new equation (DOCF = 2.76W-0.44) with moisture content in the landfill that actual methane flux data are unavailable. Moisture content is a major ecological parameter on the anaerobic biodegradability of the solid waste in the landfill. Another methodology is to use L0,Landfill/L0,BMP ratio. The L0,Landfill could be determined by a regression analysis if methane flux data were available.

In Korea, many drinking water treatment plants (DWTPs) have introduced and are going to introduce biological activated carbon (BAC) process to treated dissolved organic matter (DOM) in water which are difficult to control by conventional water treatment processes. Even though more decade have passed since introduced BAC in Korea, most of BAC operating method was followed to the modified sand filter operating manuals. In case of BAC backwashing, many DWTPs set the periods of backwashing about 3∼5 days. In this study, we have collected data to set the proper BAC backwashing periods from both pilot-plant and real DWTPs. We had measured heterotrophic plate count (HPC), turbidity, water temperature, dissolved organic carbon (DOC) and headloss from just after backwashing to the next backwashing time for two years. Considering water quality factors, the BAC run time from backwashing to the next backwashing could extend more 30 days without water quality deterioration if the head loss do not reach the limited level which depends on each BAC facilities’ condition. It means the BAC treated water could be saved in the proportion of extended the backwashing period to the existing backwashing period.

본 논문은 선형계획모형을 이용하여 H 아리수 정수 센터의 최적 취수량 결정 방법을 연구 하였다. 현재 H 아리수 센터에서는 관리자의 경험과 숙련도에 의지하여 취수량을 결정하고 있다. 그런데 매시 변하는 수요를 만족 시키면서 시간대 별로 요금이 서로 다른 전력의 사용을 최소화 하는 취수량 결정은 근무자들의 경험과 숙련도를 넘어서는 간단한 문제가 아니다. 따라서 수리적 기법 중 하나인 선형계획모형을 이용해 취수량을 결정하고, 비용 절감을 시도하였다. 본 연구에서 제안한 선형계획 모형은 수요예측치를 기본 입력자료로 사용하고 있는데 예측오차가 발생할 경우 정수지 높이 제한을 위반하는 경우가 발생한다. 이를 해결하기 위해서는 정확한 수요예측이 선행되어야 한다. 그러나 아무리 좋은 예측 기법을 사용하더라도 실수요와 오차는 있게 마련이고 이는 여전히 높이 제한의 제약을 만족 시키지 못하는 결과를 불러일으킨다. 따라서 예측오차를 수용 할 수 있는 안전 마진 상수를 이용한 대안을 제안하였다. 본 연구에서 제안한 선형 계획 모형을 통한 취수량 결정은 수위 모니터링을 위해 항시 작업자가 근무 할 필요가 없기 때문에 인건비 면에서도 많은 절약이 예측되어 총 비용 감축은 훨씬 더 많으리라 기대된다.

이 연구의 목적은 다종에너지 X선 빔의 유효에너지를 결정하는데 있다. 80 kVp X선 빔에 대한 알루미늄의 반가층은 광자극형광나노닷선량계들(OSLnDs)을 사용하여 측정하였다. 선감쇠계수(μ)는 측정된 반가층을 사용하여 계산하였다. 그리고 질량감쇠계수(μ/ρ)는 알루미늄의 밀도로 선감쇠계수를 나누어 얻었다. 얻어진 질량감쇠계수의 유효에너지(Eeff)는 미국표준기술연구소(NIST)에서 주어진 알루미늄의 광자에너지들에 대한 X선질량감쇠계수들의 자료를 사용하여 결정하였다. 결과로서, 반가층, 선감쇠계수 및 질량감쇠계수는 각각 2.262 ㎜Al, 3.06 ㎝-1, 1.114 ㎠/g이다. 그리고 유효에너지는 29.79 keV에서 결정되었다.

The purpose of this paper is to detect the fiber stiffness degradation of GFRP plates from natural frequency response data. The combined finite element analysis using ABAQUS program and the inverse algorithm described in this paper may allow us not only to detect the deteriorated elements from the mirco mechanical point of view. Several numerical results show that the proposed system is computationally efficient in identifying fiber stiffness degradation for complex structures such as composites.