We aimed to evaluate the effectiveness of ensemble optimal interpolation (EnOI) in improving the analysis of significant wave height (SWH) within wave models using satellite-derived SWH data. Satellite observations revealed higher SWH in mid-latitude regions (30o to 60o in both hemispheres) due to stronger winds, whereas equatorial and coastal areas exhibited lower wave heights, attributed to calmer winds and land interactions. Root mean square error (RMSE) analysis of the control experiment without data assimilation revealed significant discrepancies in high-latitude areas, underscoring the need for enhanced analysis techniques. Data assimilation experiments demonstrated substantial RMSE reductions, particularly in high-latitude regions, underscoring the effectiveness of the technique in enhancing the quality of analysis fields. Sensitivity experiments with varying ensemble sizes showed modest global improvements in analysis fields with larger ensembles. Sensitivity experiments based on different decorrelation length scales demonstrated significant RMSE improvements at larger scales, particularly in the Southern Ocean and Northwest Pacific. However, some areas exhibited slight RMSE increases, suggesting the need for region-specific tuning of assimilation parameters. Reducing the observation error covariance improved analysis quality in certain regions, including the equator, but generally degraded it in others. Rescaling background error covariance (BEC) resulted in overall improvements in analysis fields, though sensitivity to regional variability persisted. These findings underscore the importance of data assimilation, parameter tuning, and BEC rescaling in enhancing the quality and reliability of wave analysis fields, emphasizing the necessity of region-specific adjustments to optimize assimilation performance. These insights are valuable for understanding ocean dynamics, improving navigation, and supporting coastal management practices.

With the growth of silicon-based semiconductor sensors in the global sensor market, advancements in body motion detection for wearable devices and sustainable health monitoring have accelerated. This has led to a significant attention on various sensors with excellent flexibility and stretchability, such as PDMS, in numerous applications. In this study to adjust the sensitivity of conventional conductive pressure sensors, a porous sponge structure was initially created using a sugar template method. The polymer was prepared with four different ratios (5:1, 10:1, 20:1, 30:1) to achieve varying flexibilities. To ensure conductivity, the sponge was coated using a dip-coating method with a 3wt% CNT solution. The conductive sponges with various ratios were tested for sensitivity, demonstrating characteristics suitable for a wide range of pressure sensing applications.

본 연구는 청소년들의 대인관계 상담이 증가하는 추세에 주목하여, 개 인의 성격 기본구조와 특성을 설명해 주는 성격 5요인과 대인관계에 부 정적인 영향을 주는 거부민감성 간의 관계에서 자기격려의 매개효과를 확인하기 위해 수행되었다. 연구목적을 달성하기 위해 2020년 4월부터 8월까지 전국의 중학생과 고등학생 314명을 대상으로 자기보고식 설문 조사를 실시하였으며, 수집된 자료에 대해 기술통계, 일원분산분석, 피어 슨 상관관계분석, 회귀분석을 실시하여 다음과 같은 결과를 도출하였다. 첫째, 성격 5요인과 거부민감성, 자기격려 간에는 유의한 상관관계가 있 었다. 둘째, 자기격려는 성격 5요인과 거부민감성의 관계에서 부분 매개 하였다. 이는 청소년이 성격적 특성으로 인해 거부민감성을 크게 가질 수 있다 하더라도, 자기격려를 통해 이를 완화 시킬 수 있음을 시사한다. 본 연구의 결과 청소년의 성격 요인에 따른 대인관계 문제 해결을 위한 심리적 개입 방법으로 자기격려의 중요성을 나타내고 있다. 이에 기반하 여 대인관계 상담의 심리적 개입방법으로 자기격려 기법을 활용하는 후 속연구를 제안하였다.

Recent earthquakes in Korea, like Gyeongju and Pohang, have highlighted the need for accurate seismic hazard assessment. The lack of substantial ground motion data necessitates stochastic simulation methods, traditionally used with a simplistic point-source assumption. However, as earthquake magnitude increases, the influence of finite faults grows, demanding the adoption of finite faults in simulations for accurate ground motion estimates. We analyzed variations in simulated ground motions with and without the finite fault method for earthquakes with magnitude (Mw) ranging from 5.0 to 7.0, comparing pseudo-spectral acceleration. We also studied how slip distribution and hypocenter location affect simulations for a virtual earthquake that mimics the Gyeongju earthquake with Mw 5.4. Our findings reveal that finite fault effects become significant at magnitudes above Mw 5.8, particularly at high frequencies. Notably, near the hypocenter, the virtual earthquake’s ground motion significantly changes using a finite fault model, especially with heterogeneous slip distribution. Therefore, applying finite fault models is crucial for simulating ground motions of large earthquakes (Mw ≥ 5.8 magnitude). Moreover, for accurate simulations of actual earthquakes with complex rupture processes having strong localized slips, incorporating finite faults is essential even for more minor earthquakes.

Accurate and rapid detection of antibiotics is critical for protecting human health and the environment. To this end, we report a novel electrochemical sensor for the simultaneous detection of Levofloxacin (LFX) and Tryptophan (TRP) in dairy samples. Outstanding electrocatalytic activity for the oxidation of LFX and TRP is exhibited by the Activated Nanodiamond (AND) and Ti3AlC2 max phase ( Ti3AlC2max) nanocomposite-modified glassy carbon electrode ( Ti3AlC2max AND/GCE) featured in our sensor. High selectivity and sensitivity are achieved by the sensor, with limits of detection (LOD) of 20.47 nM and 0.309 μM for LFX and TRP, respectively. Moreover, strong anti-parasite capacity is demonstrated by the developed sensor, making it an excellent candidate for the establishment of a reliable sensing platform for antibiotic detection. Findings suggest that this novel sensor could serve as a valuable tool for monitoring the content of LFX and TRP in dairy samples and enhancing the safety of these products.

본 연구의 목적은 간호대학생의 성인지감수성, 성적자기주장, 데이트폭력간의 관계를 확인하고, 데이트폭력에 미치는 영향 요인을 파악하기 위한 서술적 연구이다. 연구대상자는 간호대학생 366명이며 자가 보고 설문을 통해 수집된 자료를 t-test, ANOVA, 상관분석, 다중회귀분석을 사용하여 분석하였다. 연구결과 성인지감수성과 성적자기주장간에는 유의한 양의 상관관계(r=.172, p<.001), 성인지감수성과 데 이트폭력간에는 유의한 음의 상관관계(r=-.105, p<.005), 성적자기주장과 데이트폭력간에도 유의한 음의 상관관계가 나타났다(r=-.024, p<.05). 간호대학생의 데이트폭력에 미치는 영향 요인은 연령(β=.184), 학 년(β=.145)이었고, 데이트폭력에 대한 설명력은 7.1%이었다. 본 연구 결과를 바탕으로 간호대학생들이 성 인지감수성과 성적자기주장을 높이고 데이트폭력을 예방할 수 있는 프로그램 개발 및 적용이 필요하다.

신뢰성 있는 토양의 이산요소모델을 개발하기 위해서는 토양의 특성을 고려하여 매개변수를 교정해야 한다. 본 연구에서는 이산요소모델을 구성하는 각 매개변수가 토양 입자의 거동에 미치는 영향을 분석하였고, 분석된 결과를 이용하여 토양의 이산요소모델을 개발하였다. 민감도 분석의 대상이 되는 매개변수는 전단 계수, 마찰 계수, 표면 에너지 등으로 선정하였으며, 교정의 기준이 되는 토양의 특성은 가비중, 안식각, 점착력 및 내부마찰각으로 선정하였다. 또한, 토성이 서로 다른 해안가, 논 및 밭을 구성하는 토양을 대상으로 연구를 수행하여 다양한 토성에 대한 적용성을 확인하였다. 결과적으로 본 연구에서 수행한 민감도 분석 결과를 이용하여 각 토양의 거동을 모사할 수 있는 이산요소모델을 교정하였으며, 시험 결과와의 비교를 통해 교정된 이산요소모델을 검증하였다.

In the present study, an innovative electrochemical sensing platform was established for sensitive detection of NO2 —. This sensor was developed using CoFe alloy encapsulated in nitrogen-doped carbon nanocubes (named as CoFe@NC-NCS), synthesized through the calcination of polydopamine-coated CoFe Prussian-blue analogues (CoFe-PBA@PDA). The morphological and electrochemical characterization reveals that the CoFe@NC-NCS possesses high electrocatalytic activity for electrochemical quantitation of NO2 —, ascribed to the huge surface area and plentiful active positions, benefiting from the porous, hollow, and core–shell structure of CoFe@NC-NCS. Under the optimal conditions, CoFe@NC-NCS/GCE possessed remarkable sensing performance for NO2 — with wide liner ranges and a detection limit of 0.015 μM. NO2 — recovery experiments in real samples exhibited recoveries in the range of 98.8–103.5%. Hence, the CoFe@NC-NCS shows great promise for the construction of electrochemical sensor with more potential application.

Bellows expansion joints enhance the displacement performance of piping systems owing to their unique geometrical features. However, structural uncertainties such as wall thinning in convolutions, a byproduct of the manufacturing process, can impair their structural integrity. This study addresses such issues by conducting a global sensitivity analysis to assess the impact of these uncertainties on the performance of bellows expansion joints under monotonic loading. Global sensitivity analysis, which examines main and nth order interaction effects, is computationally expensive. To mitigate this, we employed a surrogate model-based approach using an artificial neural network. This model demonstrated robust prediction capabilities, as evidenced by metrics such as the coefficient of determination. The sensitivity indices of the main effect for the 2-ply and 3-ply bellows at the sixth convolution were 0.3340 and 0.3233, respectively. The sensitivity index of the sixth convolution was larger than that of other convolutions because the maximum deformation of the bellows expansion joint under monotonic bending load occurs around it. Interestingly, the sensitivity index for the interaction effect was negligible (0.01%) compared to the main effect, suggesting minimal activity between uncertainty factors across convolutions. Notably, bellows expansion joints under repetitive loading exhibit more complex behaviors, with the initial leakage typically occurring at the convolution. Therefore, future studies should focus on the structural uncertainties of bellows expansion joints under cyclic loading and employ a surrogate model for comprehensive global sensitivity analysis.

To achieve permanent disposal of radioactive waste drums, the radionuclides analysis process is essential. A variety of waste types are generated through the operation of nuclear facilities, with dry active waste (DAW) being the most abundant. To perform radionuclides analysis, sample pretreatment technology is required to transform solid samples into solutions. In this study, we developed a dry ashing-microwave digestion method and secured the reliability of the analysis results through a validity evaluation. Additionally, we conducted a comparative analysis of the radioactivity of 94Nb nuclides with and without the chemical separation process, which reduced the minimum detectable activity (MDA) level by more than 65-fold for a certain sample.

The decommissioning of nuclear power plants will generate a lot of low and intermediate-level radioactive waste (LILW), and preliminary radioactive evaluation for these wastes should be carried out before decommissioning work. Mainly, Concrete, Carbon Steel, Stainless Steel-304 (SS304) and Inconel are used in many parts of nuclear power plants and considered as main resource of nuclear wastes. Depending on the material location, the number of neutrons irradiated to material varies, which can range from self-disposal waste to LILW. In this paper, activation analysis was performed to compare the radiation dose according to the presence or absence of impurity elements present in SS304. For the calculation, SS304 composition and impurity elements were used as described in the report of NUREG-3474. This report lists 41 impurity elements for SS304 and other materials. Calculation code is used ORIGEN-S module in SCALE 6.1 code. Neutron flux is used as arbitrary value that around 1E+11 level and irradiation time is set as 30 year with 10-year cooling time. In the ORIGEN-S calculation, 1g of SS304 is used for easy calculation of specific activity. The ORIGEN-S calculation results are as follows. All impurity elements contained case calculated 9.32E+07 Bq activity. In the absence of all impurity elements case and most cases shows that total Becquerel value after 10-year cooling time around 9.11E+07 Bq, and Co impurity case had larger result. The calculation was performed again by increasing the amount of impurity substances by 100 times to perform the sensitivity evaluation more reliably. Representatively, Li, N, Co, and Ba impurity elements cases were calculated to have a particularly high Becquerel. Especially Co impurity element case, a total Becquerel of 3.03E+08 was calculated. Accordingly, evaluation of impurities mixed in SS304 must be considered, and in particular, the inclusion rate for Co must be considered.

본 연구에서는 지역 영역 기상 수치 예보 모델의 여러 수평 영역 및 수평 해상도에 따른 이상적인 열대저기압 의 진로와 베타자이어의 민감도를 조사하였다. 모델의 이상적인 초기 조건은 경험적인 함수로 생성된 3차원 축대칭 모 조 소용돌이와 허리케인 활동 시기의 평균 대기 조건으로 구성된다. 이때 모델 설정에 따른 이상적인 열대저기압의 변 화를 분석하기 위하여 배경 흐름은 제거되었다. 수치 모델의 수평 영역 및 수평 해상도에 따른 이상적인 열대저기압의 민감도 실험을 수행하기 위해, 지역 영역 수치 모델로서 W RF (Weather Research a nd F orecasting) 모델을 사용하였다. 모의된 열대저기압의 바람장으로부터 베타자이어를 추출하기 위해, DFS (Double-Fourier Series) 국지 영역 고차 필터 를 사용하였다. 모델의 수평 영역의 크기가 감소할수록 베타자이어의 구조와 강도가 약해졌으며, 이는 열대저기압 진로 의 차이를 발생시켰다. 수평 영역의 크기를 본 연구의 실험에서 가장 작은 영역인 3,000 km3,000 km로 설정하였을 경 우에 베타자이어 통풍류의 서진 성분이 크게 감소하였으며, 수평 영역을 더 넓게 설정한 실험들에 비해 열대저기압의 진로가 동쪽으로 편향되었다. 본 결과는 열대저기압과 관련된 바람장 전체를 포함하지 못할 정도로 매우 작은 수평 영 역을 사용할 경우, 열대저기압의 진로가 적절히 모의 될 수 없음을 시사한다. 반면, 5,000 km5,000 km와 6,000 km 6,000 km의 수평 영역에서는 그 민감도가 매우 작게 나타났다. 수평 해상도가 감소할수록 이상적인 열대저기압의 진 로는 매우 서쪽으로 편향되었다. 베타자이어의 크기와 강도도 수평 해상도가 감소할수록 크고 더 강하게 나타났다.

PURPOSES : In this study, energy-consuming processes in asphalt plants were evaluated, and the drying and mixing processes were characterized using a thermal equilibrium equation-based model to quantitatively estimate the amount of energy consumed during the production of mixtures in asphalt concrete plants. METHODS : An energy consumption model based on the thermal equilibrium equation was used to estimate the energy consumption of the aggregate drying process that consumes the maximum energy; the energy consumed for material transportation, storage, and operation of other facilities was cited from the literature. The results were compared with the actual results obtained for recycled hot asphalt mixtures and recycled warm mix asphalt mixtures, and a sensitivity analysis was performed by varying the conditions. RESULTS : An analysis of the main processes required to produce asphalt mixtures showed that the water content had the largest impact on energy consumption (approximately 80%). This quantitatively supports the opinion of field practitioners that maximum energy is consumed during aggregate drying. Although some discrepancies were observed, the results were found to be reasonable and within the range of typical measurements. CONCLUSIONS : The thermal energy consumption estimation model provides consistent results that reflect the characteristics of the mixture and can be used to derive the thermal energy consumption rates for individual materials, such as aggregates and binders. This can be used to identify the priorities for process optimization within a plant.

The thermal integrity of spent nuclear fuels has to be maintained during their long-term dry storage. The detailed temperature distributions of spent fuel assemblies are essential for evaluating the integrity of their dry storage systems. In this study, a subchannel analysis model was developed for a canister of a single fuel assembly using the COBRA-SFS code. The thermal parameters affecting the peak cladding temperature (PCT) of the spent fuel assembly were identified, and sensitivity analyses were performed based on these parameters. The subchannel analysis results indicated the presence of a recirculation flow, based on natural convection, between the fuel assembly and downcomer region. The sensitivity analysis of the thermal parameters indicated that the PCT was affected by the emissivity of the fuel cladding and basket, convective heat transfer coefficient, and thermal conductivity of the fluid. However, the effects of the wall friction factor of the canister, form loss coefficient of the grid spacers, and thermal conductivities of the solid materials, on the PCT were predominantly ignored.

IPCC에서 발표한 제6차 기후변화 보고서에 따르면 지구온난화에 따른 해수면 상승이 가속화되고 있으며, 2100년 예상 해수면 상승은 저탄소 시나리오(SSP 1~2.6)에서는 47cm, 고탄소 시나리오(SSP 5~8.5)에서는 82cm로 분석되었다. 해수면 상승은 항만 인프라에 심각 한 피해를 입히고, 항만 내에 정박 중인 선박의 계류안전성을 저하시킬 수 있다. 본 연구에서는 해수면 상승시 부두에 계류한 선박의 계류 안전성 향상 방안을 도출하기 위해 만조시 침수 피해가 잦은 목포항을 선정하여 해수면 상승 시나리오에 따른 실제 접안 선박에 대한 계 류 평가 요소의 민감도를 분석하였다. 분석 결과, 해수면이 상승함에 따라 동일한 환경조건에서 계류라인 장력, 계선주 하중, 계류라인 수 직각도, 선체 6자유도 운동값이 대체로 증가하는 것으로 분석되었다. 또한, 마루높이가 상향되면 모든 계류 평가 요소의 값이 대체로 감소 하여 선박 및 부두의 안전성 향상에 유리한 것으로 분석되었다. 본 연구 결과는 목포항 해수면 상승에 따른 항만 및 선박의 안전성 향상 방안을 확보하기 위한 기초자료로 활용될 수 있을 것이다.

Purpose: This study was conducted to understand the ethical climate, nursing practice environment, and ethical sensitivity of hospital nurses, and to investigate the influence of the ethical environment and nursing practice environment on ethical sensitivity. Methods: The subjects of the study were 137 nurses with at least one year of work experience. Date collection was conducted from July to August 2021, using the IBM SPSS Statistics 26.0 for Windows program(IBM Corp. Armont, NY, USA), the frequency and percentage, mean and standard deviation and Independent t-test, one-way ANOVA, Pearson’s correlation, Multiple regression analysis. Results: As a result of the study, the ethical sensitivity of hospital nurses showed statistically significant differences according to age, marital status, position, and ethical educational experience. Ethical sensitivity was found to have a significant positive correlation between all sub-factors of the ethical environment and all sub-factors of the nursing practice environment. Among the sub-factors of the ethical environment, the factor influencing ethical sensitivity in this study is ‘relationship with peers (β=.20, p=.034) ’ and ‘relationship with manager (β=.24, p=.023) and the explanatory power was 42.0%, which was statistically significant (F=8.26, p<.001). Conclusion: This study confirmed that ‘relationship with peers’ and ‘relationship with managers’ influence ethical sensitivity among ethical environments. Therefore, it will be necessary to form a positive relationship between peers and managers to improve the ethical sensitivity of hospital nurses.

PURPOSES : This study aims to conduct a sensitivity analysis to determine the major factors affecting traffic accidents involving elderly pedestrians. METHODS : In this study, a regression tree model was built based on a non-parametric statistical model using data on traffic accidents involving elderly pedestrians. Using this model, we analyzed the degree of change in the probability of pedestrian fatalities. RESULTS : Results of the model analysis show that the first major factor combination affecting traffic accidents involving elderly pedestrians is speeding, night time, and road markers. The second combination is night time and arterial roads (national and local highways). The last combination that may lead to such accidents is heavy vehicles and federally funded local highways. CONCLUSIONS : Preventive measures, such as speed control, proper lighting, median strips, designation of pedestrian protection zones, and guidance of detours, are necessary to manage high-risk combinations causing accidents of the elderly.