In this study, the antioxidant activity of methanol extracts of wheat sprouts grown in wild fields and cultivated fields and harvested at various times were analyzed to compare the quality characteristics of the wheat sprouts as a function of their cultivation and harvest time, as well as for the development of functional materials. The total polyphenolic and flavonoid content, as well as antioxidant activity of the wheat extracts, were subsequently analyzed. The ABTS radical scavenging activity of the wheat extract increased from 16.97 mg TEAC/g sample on cultivation day three in cultivated field wheat sprouts to 25.99 mg TEAC/g sample after seven days of wild field cultivation. The total polyphenol content increased from 17.08 mg GA eq/100 g in cultivated field wheat sprouts grown for three days to 28.70 mg GA eq/100 g after seven days of wild field cultivation. In addition, the flavonoid content increased from 7.02 mg catechin eq/100 g (7 days) to 8.47 mg/g after 12 days of wild field cultivation. Notably, the activity subsequently decreased. These results suggest that the wheat sprouts with higher biological activity were those produced from the wild field after 20 days.

본 연구는 대목용 호박 계통들의 내냉성을 다양한 방법들로 평가 후 상호 비교하고, 수박과 접목 후 포장에서 나타나는 내냉성 양상과 비교하여 수박 재배용 호박 대목개발에 활용 가능한 내냉성 자원선발 방법을 제시하고자 수행하였다. 그 결과 내냉성 평가에 간접적으로 사용하고 있는 발아검정, 유묘 생육 및 피해검정, 단근삽목 검정법은 접목 후 포장에서 검정한 결과와 상관관계를 보이지 않았다. 포장검정 결과와 상관관계를 보인 검정법은 유묘를 1℃로 1일 처리하고 엽록소형광 값을 측정한 방법과 유묘를 1℃로 2일 처리 후 떡잎의 저온피해 정도를 비교한 방법이었고, 그 중 떡잎의 저온피해 정도를 비교한 방법이 포장검정 결과와 더 높은 상관관계(r=0.480, p=0.002)를 보여 내냉성 대목 선발에 더 적합한 것으로 나타났다.

In this study, algorithms for analyzing the torsion of buildings under earthquake excitation are developed. The algorithm and formulations to account for the torsional angle are verified by analyzing the seismic acceleration time history data. The method was applied to the reference buildings to examine their operation and usability. The reference application demonstrated that the noise-canceling scheme successfully overcame various obstacles in the field measurements. The developed method is expected to be used as a tool to support a loss assessment system for determining the direction and priority of disaster response in the event of an earthquake.

As the demand for the monitoring of VOCs increases, various unpowered colorimetric sensors are being developed, but the performance evaluation method of the developed sensors has not been systematically established. In this study, the device, experimental process, and data calculation methods for the performance evaluation of the colorimetric sensors were proposed. An aluminum chamber (70W× 128 L × 40 mm H) was designed to expose the sensor to a constant concentration of VOCs. In addition, an experimental apparatus was devised to evaluate the effect of environmental factors (temperature and humidity) affecting the ability of the sensor to detect VOCs. To calculate the color change value of the sensor corresponding to the concentration of VOCs, the ‘peak wavelength method’ that analyzes the wavelength of the highest intensity for high-concentration VOCs and the ‘spectral centroid method’ using a weighted arithmetic average for low-concentration VOCs were used. As a result of evaluating the ability of the colorimetric sensor to detect VOCs, which was made of polydimethylsiloxane (PMDS) by the method proposed in this study, the wavelength change values (bandgap shift) of the sensor for 1,000 ppm of benzene, toluene, oxylene, and acetone were 0.898 nm, 2.304 nm, 5.775 nm, and 0.249 nm, respectively. The precision was calculated by repeatedly measuring the sensing ability of the sensor 5 times for each type of VOCs. The precision of the sensor responses to benzene, toluene, o-xylene, and acetone were 15.23%, 7.84%, 4.14%, and 30.00% RSD, respectively. The method proposed in this study can be used to evaluate the performance of various types of VOCs colorimetric sensors.

PURPOSES : In general, a high-performance concrete construction method is a method of loading mixed cement and other materials on a mobile mixer equipped with a concrete plant. However, the construction cost is high because the unit cost of the mixed cement is very high and the equipment usage fee of the mobile mixer is also high. To compensate for these drawbacks, a cellular spray concrete method was developed. This is a highly functional customized concrete construction method in which admixtures are added to high-flow concrete with cellular (air bubbles) added at the site and constructed through spraying. METHODS : Field workability evaluation using cellular concrete was carried out using a spray method in 2017 and an anti-foaming agent in 2018. The test construction section was set as a new road-pavement construction site. After construction, strength, durability characteristics, and void analysis were performed to compare the construction methods. The results of laboratory tests under optimal conditions were also compared to the on-field results. By comparing the indoor mixing and the on-field results, we analyzed whether there were any problems concerning the performance expression. The economic feasibility at the initial construction stage was analyzed by comparing the existing and the cellular concrete construction methods in terms of material cost and equipment usage fee. RESULTS : In the case of cellular spray concrete, construction through spraying is cumbersome, and the need to additionally use large equipment such as a pump car and compressor constitutes a disadvantage. However, the most relevant feature is that it can be constructed not only on the floor, but also on a slope. In the case of cellular concrete with an antifoaming agent, it was possible to quickly produce high-performance concrete using on-site remixing equipment. By supplying materials to the pouring surface using a conveyor, smooth construction and construction in narrow spaces were also possible. CONCLUSIONS : The cellular concrete method allows the immediate on-site production of high-performance concrete, and it is possible to selectively apply spray construction, antifoaming agent construction, etc.

확산강조 영상은 자기공명영상에서 진단에 매우 중요한 역할을 차지하고 있다. 또한, 높은 b-value를 요구하는 검사가 늘어나는 추세로 확산강조 영상을 얻기 위하여 검사 시간이 길어지게 되며 인공물과 전체적인 신호 감소가 동반하게 된다. 본 연구에서는 확산강조 영상에서 확산 방법을 3스캔 추적 확산강조 영상(3-scan trace diffusion weighted image, tDWI) 에서 DTI의 원리를 적용한 대각선 확산강조 영상(diagonal diffusion weighted image, dDWI)로 변경하여 획득 하였을 때, 두 방법 간의 검사 시간의 단축과 영상을 비교 평가하였다. 농도가 0에서 50%까지 10% 간격인 팬텀을 제작하여 제한된 확산(restrict diffusion)을 단발 스핀에코평면영상(single shot spin echo echo planar, SE-EPI) 기법을 사용하여 검사하였다. 확산 방법을 변경하며 tDWI와 dDWI 검사를 진행하였으며, 획득한 영상을 Image J 프로그램을 이용 하여 농도별 동일한 관심 체적을 설정하여 신호를 측정 후 분석방법은 독립 T-test를 이용하고, 통계적 분석은 SAS를 통해 신호 대 잡음 비와 대조도 대 잡음 비를 비교·분석하였다. p-value 0.05를 기준으로 유의성을 검증하였다. b0를 제외한 b100 이상은 전반적으로 신호 대 잡음 비, 대조도 대 잡음 비가 크며, p-value 0.05 이상으로 나타났다. 확산 방법 간 유의하지 않지만, 전반적으로 dDWI이 tDWI에 비해 평균이 높았다. dDWI 방법이 tDWI에 비해 화질의 변화 없이 검사 시간이 18.35% 단축되는 효과가 있으며, 신호 대 잡음 비와 대조도 대 잡음 비가 소폭 향상된 것으로 나타나 다른 부위의 확산강조 영상을 사용하는 검사에 적용 시 유용할 것으로 사료 된다.

This study set up the estimates of leakage management efficiency evaluation and leakage management goal that could be used in local water distribution networks efficiency business and modernization business. The data were analyzed using data envelopment analysis and multiple regression analysis. To this end, with leakage management input indices concerning leakage reduction activities (e.g., aged pipe replacement, water meter replacement, leakage restoration, and leakage detection) and leakage management calculation indices (e.g., the increase of revenue water ratio and the reduction of leakage ratio), the data on 22 K-water consignment local water supply systems were analyzed for the years from 2004 through 2018. Using the results of efficiency analysis by data envelopment analysis, the other DMUs (Decision Making Unit) benchmarked the DMU with the highest efficiency to maximize the leakage management efficiency for all DMUs. Through this, leakage management goal estimates were drawn with the input indices of four leakage reduction activities and calculation indices of the increase of revenue water ratio and the reduction of leakage ratio by multiple regression analysis for each group based on the revenue water ratio and leakage ratio. The correlation coefficients of the leakage management goal estimate for the criteria for the revenue water ratio amounted to 0.553 and 0.771. The correlation coefficients of the leakage management goal estimate for the criteria for leakage ratio were 0.397 and 0.865. Accordingly, we estimated the quantity and priority of four leakage reduction activities for the target leakage ratio and revenue water ratio.

목조건축물에 주로 적용되고 있는 철물 접합 시스템은 모재인 나무와 접합부재인 철재 간의 강도 차이 및 재질의 이질성으로 인한 외관상의 위화감 등이 문제점으로 대두되고 있다. 재료 가공의 편의성으로 프리컷 시스템이 도입되었고, 시공성 을 해결하기 위한 새로운 재료 및 시스템의 개발이 요구된다. 본 연구에서는 자연재료를 그 원료로 하여 미관상 목조건축물에 위화감이 없는 황토 압밀 플레이트를 개발하였다. 황토 및 소석회를 원료로 하여 제작한 시험체의 양생방법(기건 양생, CO2 양 생)에 따른 성능을 평가하기 위해 질량 변화, 지압 강도, 흡수율, 표면상태, 열중량변화 측정 및 SEM을 통한 생성광물의 미시적인 부분을 관찰하였다. 또한 제조과정에서의 온실가스 배출 및 흡수에 따른 환경성능평가를 수행하였다. 기건 양생한 시험체에 비해 CO2 챔버에 양생한 시험체는 원료인 소석회의 탄산화 반응으로 인한 탄산칼슘의 생성으로 역학적 성능이 향상되었다는 것을 알 수 있었으며, 원료인 소석회의 탄산화반응으로 인해 생석회 제조시 발생하는 CO2량의 70% 이상을 재흡수 한다는 것을 알 수 있었다.

This study was carried out in order to help establish a continuous efficiency test method to evaluate the performance of chemical odorants. We designed a continuous efficiency test device, and conducted several experiments during 240 mins with D.W. and two chemical deodorants for several specified substances, and a complex odor compound. Based on the results, it was confirmed that the deocorant test only for ammonia and amine could yield no useful outcome because the solubility of the two compounds was very high. Henceforth, simultaneous tests for sulfides, mercaptans, aldehydes, and so on, shoud be conducted in order to ascertain the accurate deodorant performance results. It is also clear that the concentration of target compounds and reaction time are very important for the purposes of accurate deodorant tests. In addition, information about the absorption efficiency with regard to complex odor compound such as DMS+DMDS may be important and the results based on air dilution olfactory method should be provided. It is believed that this study can make a contribution to formulating the correct standards regarding the testing of deodorants and the application of such tests.

A well-established characterization method is required in powder bed fusion (PBF) metal additive manufacturing, where metal powder is used. The characterization methods from the traditional powder metallurgy process are still being used. However, it is necessary to develop advanced methods of property evaluation with the advances in additive manufacturing technology. In this article, the characterization methods of powders for metal PBF are reviewed, and the recent research trends are introduced. Standardization status and specifications for metal powder for the PBF process which published by the ISO, ASTM, and MPIF are also covered. The establishment of powder characterization methods are expected to contribute to the metal powder industry and the advancement of additive manufacturing technology through the creation of related databases.

목적 : 본 연구에서는 다양한 방법들을 이용하여 토릭렌즈 마킹 회전량을 평가할때 일치도를 평가측정하고자 하였다. 방법 : 모형안과 콘택트렌즈 착용이 가능한 57안(평균 24.79±1.29세)을 대상으로 토릭소프트렌즈를 제조사의 가이드라인에 따라 피팅한 후, 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기와 세극등 현미경을 사용하여 회전 평가를 진행했을 때의 서로 다른 검사자 간의 검사 결과값을 비교 분석하였고, 서로 다른 회전평가 방법 간의 일 치도는 블랜드 알트만 분석을 사용하였다. 결과 : 서로 다른 검사자 간 같은 회전평가 방법으로 토릭소프트렌즈의 회전량을 측정하였을 때, 측정값의 평 균 차이가 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기, 세극등 현미경 평가 방법 각각 –0.50, -0.70, -0.30, -0.13°로 유사한 결과를 보였다. 회전평가 방법 간 비교에 대해서는 사진 촬영과 각도기 어플리케이션을 사용했을 때, 허용 오차 범위(5°) 내의 측정값이 각각 74.56%, 75.44%로 비교적 낮은 신뢰도를 보였고 휴대용 돋 보기를 사용한 방법에서는 95.61%로 높은 신뢰도를 보였다. 결론 : 토릭소프트렌즈 처방에서 세극등 현미경을 사용할 수 없어도 사진 촬영, 핸드폰 각도기 어플리케이션, 휴대용 돋보기를 통해 토릭소프트렌즈 회전평가에 대한 임상적으로 유용한 결과를 얻을 수 있다.