PURPOSES : This study aims to provide quantitative profile values for the objective evaluation of concrete surface profile (CSP) grades in concrete structures. The main aims are to quantify the CSP grade required for concrete surface pretreatment and proposing a more suitable CSP grade for structural maintenance. METHODS : Initially, the challenges in measuring concrete surface profiles were outlined by analyzing pretreatment work and profile samples of concrete pavements. Theoretical foundations for quantifying concrete surface roughness were established, and regression models including linear regression, cubic regression, and log regression were selected. Additionally, the interquartile range anomaly removal technique was employed to preprocess the data for regression modeling. RESULTS : Concrete CSP profiles were measured through indoor tests, and the measured data were quantified. Linear regression, cubic regression, and log regression models were applied to each CSP grade for comparative analysis of the results. Furthermore, comparative studies were conducted through adhesion strength tests based on the CSP grade. CONCLUSIONS : Our results are expected to establish objective standards for the pretreatment stage of concrete repair and reinforcement. The derived reference values can inform standards for the restoration and reinforcement of concrete structures, thereby contributing to performance improvement. Moreover, our results may serve as primary data for the repair and reinforcement of various concrete structures such as airports, bridges, highways, and buildings.

The operation time of a disposal repository is generally more than one hundred years except for the institutional control phase. The structural integrity of a repository can be regarded as one of the most important research issues from the perspective of a long-term performance assessment, which is closely related to the public acceptance with regard to the nuclear safety. The objective of this study is to suggest the methodology for quantitative evaluation of structural integrity in a nuclear waste repository based on the adaptive artificial intelligence (AI), fractal theory, and acoustic emission (AE) monitoring. Here, adaptive AI means that the advanced AI model trained additionally based on the expert’s decision, engineering & field scale tests, numerical studies etc. in addition to the lab. test. In the process of a methodology development, AE source location, wave attenuation, the maximum AE energy and crack type classification were subsequently studied from the various lab. tests and Mazars damage model. The developed methodology for structural integrity was also applied to engineering scale concrete block (1.3 m × 1.3 m × 1.3 m) by artificial crack generation using a plate jacking method (up to 30 MPa) in KURT (KAERI Underground Research Tunnel). The concrete recipe used in engineering scale test was same as that of Gyeongju low & intermediate level waste repository. From this study, the reliability for AE crack source location, crack type classification, and damage assessment increased and all the processes for the technology development were verified from the Korea Testing Laboratory (KTL) in 2022.

Metakaolin-based geopolymers have shown promise as suitable candidates for 14C immobilization and final disposal. It has been shown that the physicochemical properties of metakaolin wasteforms meet, and often far exceeding, the strict compression strength and leaching acceptance criteria of the South Korea radioactive waste disposal site. However, it is not possible to analyze and characterize the internal structure of the geopolymer wasteform by conventional characterization techniques such as microscopy without destruction of the wasteform; an impractical solution for inspecting wasteforms destined for final disposal. Internal inspection is important for ensuring wastes are homogenously mixed throughout the wasteform and that the wasteform itself does not pose any significant defects that may have formed either during formulation and curing or as a result of testing prior to final disposal. X-ray Computed Tomography (XCT) enables Non-Destructive Evaluation (NDE) of objects, such as final wasteforms, allowing for both their internal and external, characterization without destruction. However, for accurate quantification of an objects dimensions the spatial resolution (length and volume measures) must be know to a high degree of precision and accuracy. This often requires extensive knowledge of the equipment being used, its precise set-up, maintenance and calibration, as well as expert operation to yield the best results. A spatial resolution target consists of manufactured defects of uniformed dimensions and geometries which can be measured to a high degree of accuracy. Implementing the use of a spatial resolution target, the dimensions of which are known and certified independently, would allow for rapid dimensional calibration of XCT systems for the purpose of object metrology. However, for a spatial resolution target to be practical it should be made of the same material as the intended specimen, or at least exhibit comparable X-ray attenuation. In this study, attempts have been made to manufacture spatial resolution targets using geopolymer, silica glass, and alumina rods, as well as 3D printed materials with varying degrees of success. The metakaolin was activated by an alkaline activator KOH to from a geopolymer paste that was moulded into a cylinder (Diameter approx. 25 mm). The solidified geopolymer cylinder as well as both the silica glass rod and alumina rod (Diameter approx. 25 mm) we cut to approximately 4 mm ± 0.5 mm height with additional end caps cut measuring 17.5 mm ± 2.5 mm height. All parts were then polished to a high finish and visually inspected for their suitability as spatial resolution targets.

DLC has been attractive as semiconductor materials for solar cell due to its biological friendliness, flexible microstructures, and especially its tunable band gap. In order to fabricate high-efficiency multiband gap solar cell, it is important to control the sp3/ sp2 bonds ratio of DLC film corresponding to optical band gap (Eg). There are many references reporting the relations among the fabrication conditions, Eg, sp3/ sp2, and ID/ IG. However, a more comprehensive database is needed for controllable fabrication. Especially, the quantitative relationship of sp3/ sp2 ratio to Eg of DLC film by PECVD is unclear. In this paper, 36 sets of DLC films were fabricated by RF-PECVD. Characterization methods of XPS, Raman spectroscopy, and IR absorption have been used to determine the sp3/ sp2 ratio of DLC films. UV/visible light absorption method has applied to evaluate Eg. The Eg obtained is in the range 1.45–3.0 eV. Our results agree well with the references. The XPS spectra gives a linear relationship as Eg = − 0.161 (± 0.136) + 26.095 (± 1.704) · {sp3 (XPS)/sp2}, the Raman spectra shows a linear function that Eg = 1.327 (± 0.046) + 0.428 (± 0.036) · (ID/IG), as well as the FTIR analysis demonstrates that Eg = − 0.492 (± 0.093) + 0.464 (± 0.044) · {sp3 (FTIR)/sp2}.

1. 본 연구의 목적은 한국 공여기관이 수행한 ODA 사업을 대상으로 수원국 주민에 의한 정량적 평가방법이 사후평가에 적용가능한지를 탐구함. 2. PLS-SEM 모형을 통해 OECD/DAC 5대 기준별 점수를 산출하였으며 추가로 ODA 성과가 주민 만족도와 공여국 이미지에 미치는 영향관계를 분석함. 3. 주민은 OECD/DAC 5대 기준 중 영향력에 대해 가장 낮은 점수를 부여하였으며 ODA 성과가 높을수록 주민 만족도와 공여국 이미지는 높아지는 것으로 나타남. 4. 본 연구를 통해 ODA 사업 사후평가에 주민참여형 정량적 평가의 적용가능성을 확인하였으며 본 평가방법은 공여국 전문가 주도의 평가방식을 보완하는 목적으로 그 유용성이 클 것으로 기대함.

목 적 : Synthetic MR을 기반으로 한 MAGiC은 수학적 연산 기법을 이용하여 각 픽셀의 T1, T2 relaxation map을 얻는 검사기법이다. 이를 이용해 한 번에 획득한 data로 다양한 대조도의 영상을 나타낼 수 있다. 하지만 아직까지 MAGiC의 이완 시간(relaxation time) 측정에 있어서 정확한 기준이 확립되어 있지 않다. 이에 본 연구에서는 자체 제작한 조영제 팬텀을 이 용해 MAGiC과 conventional spin echo(CSE) sequence로 T1, T2 이완시간과 이완율을 측정하고, 이를 기준으로 MAGiC 과 CSE를 비교 평가하였다. 대상 및 방법 : Gadolinium-based contrast agent(GBCA)팬텀을 제작하였으며 MAGiC과 CSE sequence를 사용하였다. T1 이완시간의 측정은 총 15개의 TR(20~10000msec)을 설정하였으며, TR을 제외한 다른 변수는 고정하였다. T2 이완시간 측정은 총 13개의 TE(10~560msec)를 설정하였으며, 마찬가지로 TE를 제외한 다른 변수는 모두 고정하였다. MAGiC과 CSE의 T1,T2 이완 시간을 측정하였으며 이완율의 오차율(error rate)을 통해 각 농도의 구간별 차이를 비교하였다. 결 과 : CSE와 MAGiC의 T1과 T2 이완시간 측정 결과 CSE T1이 MAGiC T1보다 평균 114.92 더 높게 측정되었으며 CSE T2 역시 MAGiC T2보다 평균 244.66 더 높게 측정되었다. 하지만 통계 분석 결과 T1 이완시간의 차이는 p>0.05로 통계적 유의함이 없었다. 반면 T2 이완시간의 차이는 p<0.05로 유의한 차이를 보였다. 각 몰농도별 relaxivity를 측정한 결 과 CSE의 r1은 평균 3.49±0.28, MAGiC의 r1은 평균 3.27±1.09로 측정되었으며, 몰농도 2mM과 4mM 구간에서 CSE의 r1이 각각 3.15, 3.47을 보여 MAGiC의 r1값인 1.48, 0.74와는 매우 큰 차이가 있었다. CSE의 r2는 3.97±0.63, MAGiC의 r2는 8.42±3.16으로 측정되었으며, 특히 몰농도가 낮은 0.025, 0.05, 0.1mM에서 CSE의 r2는 각각 2.38, 3.60, 3.55인 반 면 MAGiC의 r2는 각각 10.33, 14.26, 15.02로 약 5배의 차이가 나타났다. 결 론 : MAGiC은 CSE와 비교하여 T1이완시간의 측정은 CSE를 대변할 만큼 구현되었지만 T2 이완시간의 측정은 CSE에 비해 잘 표현하지 못함을 알 수 있었다. 따라서 향후 MAGiC은 T2 이완시간을 통한 영상의 표현에 있어서 CSE와의 차이를 보완 할 수 있는 많은 연구가 진행되어야 할 것으로 사료된다

경수로 사용후핵연료 수송/저장용기의 핵임계 해석은 사용후핵연료내의 악티나이드핵종 및 핵분열생성물 함유량에 대한 불확실성을 이유로 신연료로 가정된 가상의 연료를 선정하여 평가해오고 있다. 그러나 이러한 평가방법은 용기 설계 시 과 도한 임계여유도를 유도하여 경제적 손실을 유발할 수 있는 단점이있다. 이와 같은 단점을 극복하기 위하여 최근 연소도이 득효과(burnup credit, BUC)를 반영한 수송저장용기의 설계 및 상용화를 위한 연구가 추진되었다. 이에 본 연구에서는 한국 원자력환경공단에서 개발중인 금속겸용용기를 대상으로 연소도 이득효과적용 시 핵임계 안전성(criticality safety)에 영향을 미칠 것으로 예상되는 ‘노심 운전인자’, ‘축방향 연소도 분포’, ‘오장전 사고상황’에 대하여 핵임계 평가를 수행하였다. 그 결과 노심운전인자 중 저농축, 고연소도일 때 비출력에 따른 핵임계 변화가 크게 평가되었으며, 고연소도 사용후핵연료에서 End effect가 양의 값을 나타내었다. 특히 오장전에 의한 유효증배계수는 최대 0.18467증가하였으므로, 연소도이득효과를 적용 할 경우 필수고려사항임을 확인하였다. 본 연구결과는 국내모델(금속겸용용기)의 연소도 이득효과 적용기술 개발 및 사용 후핵연료 장전 시 일어날 수 있는 오장전 사고를 방지하기 위한 운영절차 개발에 참고자료로 활용될 수 있다.

Purpose: Since the advent of smart phones, the amount of time spending on their use has rapidly increased and there are several health concerns regarding sight, causing prolonged smart phones viewing. The purpose of this study was to estimate how much eyes become fatigued based on quantitative electroencephalogram(qEEG) and to analyze the correlation between the fatigue and attention using event-related potentials(ERPs) as objective assessments. Methods: here were thirty, healthy, right-handed subjects(male 15, female 15) participating in this study. 64-channel of qEEG data with their eye-closed was collected and they performed Go/Nogo tasks before and after watching smart phones. A questionnaire regarding the visual fatigue was also collected in both conditions. The changes of pre- and post-task of watching smart phones were analyzed and compared in terms of four wavebands and algorithms, delta(δ), theta(θ), alpha(α), beta(β), (α+ θ)/ β, α/ β, (α+θ)/(α+β), and θ/ β for fatigue detection. Results: The results clearly show that all four energy values of qEEG and algorithms related to the fatigue in the post-viewing condition significantly changed than those in the pre-viewing condition. As seen in the results of ERP, nogo-N2 amplitude only on Fz electrode was slightly higher and nogo-P3 amplitudes on Fz and Cz were considerably lower in the post-task than in the pre-watching. However, there were no significant differences of go-N2 and P3 found at any electrodes. The results of behavioral performance demonstrate that the error rates(ER) of nogo-condition were obviously increased after using smart phones and there was a tendency for reaction time(RT) to be delayed compared with before watching it. Conclusions: This research denotes that it can be a fairly useful measure for using qEEG and ERP when assessing the visual fatigue. Its findings suggest that a sustained smart phone viewing leads to the visual fatigue and it can have adverse effects on distraction.

This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< 18.5°), medium risk(18.5°～ 36.0°), high risk(> 36.0°), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.

본 논문에서는 사용자의 감성적 요구에 적합한 이미지를 탐색한 후 문-스펜서(P. Moon&D. E. Spencer)의 색채 조화론에 기초하여 조화의 정도가 가장 높은 이미지들을 순위별로 제시하는 이미지 검색법을 제안하였다. 이미지 검색은 키워드로 주어진 감성어휘와 관련된 색채성분이 가장 많이 포함된 이미지 화상을 검색하여 미도(Aesthetic Measure)를 계산한 후 순위별로 제시하는 방법으로 이루어진다. 문-스펜서의 색채 조화론을 적용한 이미지 검색법의 타당성을 검증하기 위하여 200개의 샘플 이미지를 대상으로 시스템이 제시한 미도순위와 사용자 만족도 평가에 의한 순위를 비교하였다. 분석결과 15개의 감성어휘별로 시스템이 출력한 이미지들의 미도 순위에 대한 실험 참가자들의 평균 만족도는 7점 척도 중 5.0으로 나타났다. 또한 시스템이 산출한 이미지들의 미도 순위와 설문 참가자가 평가한 만족도 순위 사이와의 일치 여부를 알아보기 위해 상관분석을 실시한 결과 감성어휘 'Clear'를 제외한 14개의 어휘 모두에서 상관계수 0.5 이상의 양호한 정적상관을 보였다. 이와 같은 연구결과로부터 문-스펜서의 색채 조화론을 바탕으로 제안한 감성검색법이 이미지 데이터베이스와 같은 시각자극의 검색에 있어서도 사용자의 감성을 적절히 반영할 수 있는 가능성을 확인하였다.

Sperm chromatin integrity is essential for successful fertilization and development of an embryo. Reported here is a quantification of DNA fragments which is intimately associated with reproductive potential to provide one of criteria for sperm chromatin integrity. Three sperm populations were considered: CONTROL (no treatment), UV irradiation (48mW/, 1h) and (oxidative stress induced by hydrogen peroxide, 10 mM, 50 mM and 100 mM). DNA fragments in boar sperm were evaluated by using ligation-mediated quantitative real-time polymerase chain reaction (LM-qPCR) assay, which relies on real-time qPCR to provide a measure of blunt 5' phosphorylated double strand breaks in genomic DNA. The results in agarose gel electrophoresis showed no significant DNA fragmentation and no dose-dependent response to . However, the remarkable difference in shape and position was observed in melting curve of LM-qPCR. This result supported that the melting curve analysis of LM-qPCR presented here, could be more sensitive and accurate than previous DNA fragmentation assay method.

We measured the non-carbon content of single-walled carbon nanotubes (SWCNTs) in SWCNT soot using thermogravimetric analysis. The weight increased percentage by the oxidation of metal in the raw soot is well obtained by TGA graph which was confirmed with ICP-AES, XRD, and XPS. This work will be very useful for the purity precise evaluation of SWCNT with UN-vis-NIR spectroscopy.

In this study, with the objects of 173 institutions of university and research institutions, investigation was carried out through visit investigation and questionnaire investigation. Frequency and strength of occurrences was acquired mainly through universities and research institutions which have reported occurrences of accidents to the Ministry of Education, Science, and Technology. Quantitative danger evaluation was conducted through frequency and strength of occurrences. Case study was carried out by selecting bio science laboratory of university and as the result of this study, degree of danger among the inspection objects of bio science laboratories, laboratory work place was evaluated as the most dangerous with the scores of 155.00 and as the result of average danger level, compression gas cylinder was evaluated as the most dangerous with the scores of 6.4000.