Purpose: This study aimed to examine the impact of resilience and learning agility on organizational commitment among nurses who experienced job rotation. Methods: This descriptive correlational study was conducted with a convenience sample of 180 nurses who experienced job rotation within one year at a university hospital in C city. Data were collected from July to August 2022. A total of 176 valid responses were analyzed using scales measuring organizational commitment, resilience, and learning agility. Data analysis included descriptive statistics, Pearson's correlation coefficients, and multiple regression using the SPSS 27.0 program. Results: The results demonstrated that resilience emerged as the most significant predictor of organizational commitment among nurses who experienced job rotation, followed by satisfaction with their current department and the reason for departmental change. Conclusion: The results indicate that resilience significantly influences organizational commitment among job-rotated nurses. Future research should focus on developing and implementing programs to enhance resilience among nurses who experience job rotation, thereby improving their organizational commitment.

Oyster mushrooms were analyzed to confirm the effect of installing a convection fan on the uniformity of the environment inside the cultivation house, the quantity of fruiting bodies, and marketability for stable production. When using a convection fan, it was confirmed that the temperature, relative humidity, and CO2 concentration were maintained more uniformly than when not used.As for the characteristics of the fruiting bodies, the quantity per bottle was 177.3 g when using a convection fan, which was 17% higher than when not used, and the individual weight was 49% higher. In addition, the cap diameter, cap thickness, and stem thickness increased slightly in the convection fan treatment, and the stem length was shorter.

본 연구의 목적은 동아시아 고대 순환론이 과거 지향적 사고가 아니라 동 아시아의 독특한 지식·정보 데이터베이스 구축 과정이었음을 논증하는 것이 다. 첫째, 엘리아데가 영원회귀의 신화에서 제시한 ‘원형과 반복’을 이용하 여 고찰한 결과, 고대 동아시아 순환론이 근대에 직선적 시간관으로 발전하지 못한 원인은 다음과 같다. 동아시아인들은 고대 히브리 민족과 같은 강력한 힘을 가진 절대자 창조신을 필요로 하지 않았기 때문에 미래로 추동해 나갈 힘이 약했으며, ‘자연’을 ‘원형’으로 삼으면서 자연 주기와의 동조성이 강해 순 환론을 벗어나기 어려웠다. 둘째, 고대 동아시아 순환론이 과거를 중시하는 보수적 사고임에도 기원후 18C 이전까지 천 수백 년간 동아시아가 서구보다 선진 문화와 문명을 이룰 수 있었던 이유는 다음과 같다. 고대 서구인들은 ‘원 형’을 체험하는 순환의 과정에서 ‘과거 시간’을 폐기했지만, 동아시아인들은 순환의 과정에서 ‘과거’를 축적하여 후대에 계속 활용할 수 있는 지식·정보 DB를 구축했다는 것이다. 주업이 정주 농경인 동아시아는 자연 주기에 동기 된 지식정보를 축적하는 데에 서구보다 유리했으며, 이 경험적 지식을 활용하여 기원후 서구를 능가하는 번영을 이룰 수 있었다. 그렇다면 동아시아에서 과거를 소중히 하고 순환론을 선택한 이유는 과거 지식과 정보를 재활용하기 위한 필연적 과정이라 볼 수 있으므로, 이를 과거지향의 소극적 사고로 평가 하는 것은 서구 중심적 관점이라 할 수 있다.

As various types of products are produced in a single production system, it is important to determine a scheduling policy that selects one of the different types. In addition, the failure of processes in a line need to be considered due to machine failure, raw material supply and demand, quality issues, and worker absence, etc. Therefore, we studied production systems with various product types, dedicated buffers for each product type, Bernoulli equipment, and WIP-based scheduling or cyclic scheduling. To analyze such system exactly, we introduced a method to analyze the performance such as production rate, WIP level, blocking probability and starvation probability based on Markov chains and derived various characteristics. Especially, assuming that equipment does not need to select the type it just tried, the flow rate is no longer conserved and increasing buffer capacity does not guarantee increase production rate. The performance comparison between WIP-based and cyclic policy is studied as well.

본 연구는 대서양연어 (Salmo salar) 파르를 대상으로 다른 광주기 (L24:D0, L15:D9, L12:D12, L9:D15, L0:D24)에 60일간 노출시킨 후에 생존, 성장 및 혈액성분에 관한 영향을 연구하였다. 실험종료 시 생존율의 측정결과 L24:D0 실험구는 90.0± 7.1%, L12:D12 실험구는 87.5±3.5%, L9:D15 실험구는 97.5±3.5%, L24:D0 실험구는 97.5±3.5%로 나타났으나 각 실험구 간의 유의한 차이는 없었다. 실험종료 시 각 실험구의 증체율 (weight gain, WG), 일간성장률 (specific growth rate, SGR) 및 사료효율 (feed efficiency, FE)의 변화를 측정한 결과, 광주기 차이에 따른 유의한 변화는 보이지 않았다. 혈장 성분 중 ALT (alanine aminotransferase), AST(Aspartate Aminotransferase) 및 glucose는 L24:D0 실험구가 다른 실험구에 비해 유의하게 상승한 것으로 나타났다. 혈장 cortisol은 L24:D0와 L0:D24가 가장 높았으며, L15:D9와 L9:D15와는 유의한 차이는 보이지 않았지만, L12:D12보다는 유의하게 높은 것으로 나타났다. 혈장 sodium (Na+), potassium (K+), chloride (Cl-) 및 osmolality는 각 실험구 간에 유의한 차이는 보이지 않았다. 본 연구결과, 대서양연어 파트에 대해서 60일간 다른 광주기에 노출 시켰을 때 생존 및 성장도의 변화는 보이지 않았으나, L24:D0 실험구에서 조직손상과 스트레스 지표인 혈장 ALT, AST, cortisol 및 glucose 농도가 유의하게 상승하는 것으로 나타났다.

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

이미지 분석을 통한 재료의 상 구분은 재료의 미세구조 분석을 위해 필수적이다. 이미지 분석에 주로 사용되는 마이크로-CT 이미 지는 대체로 재료를 구성하고 있는 상에 따라 회색조 값이 다르게 나타나므로 이미지의 회색조 값 비교를 통해 상을 구분한다. 순환골 재의 고체상은 수화된 시멘트풀과 천연골재로 구분되는데, 시멘트풀과 천연골재는 CT이미지 상에서 유사한 회색조 분포를 보여 상 을 구분하기 어렵다. 본 연구에서는 Unet-VGG16 네트워크를 활용하여 순환골재 CT 이미지로부터 천연골재를 분할하는 자동화 방법 을 제안하였다. 딥러닝 네트워크를 활용하여 2차원 순환골재 CT 이미지로부터 천연골재 영역을 분할하는 방법과 이를 3차원으로 적 층하여 3차원 천연골재 이미지를 얻는 방법을 제시하였다. 선별된 3차원 천연골재 이미지에서 각각의 골재 입자를 분할하기 위해 이 미지 필터링을 사용하였다. 골재 영역 분할 성능을 정확도, 정밀도, 재현율 F1 스코어를 통해 검증하였다.

This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.

해양폐기물 중 하나인 패각의 발생량은 매년 증가하고 있으나, 대부분이 해안 근처에 야적되거나 방치되어 환경적·사회적으로 문 제가 되고 있다. 천연 골재 부존량 감소에 따른 골재 대체재로서 패각이 사용된다면 재료 수송에 따른 물류비용을 효과적으로 감축시 킬 수 있어 자원 재활용을 활성화할 수 있다. 본 연구에서는 3D 콘크리트 프린팅 기술을 활용한 해양 구조물의 건설 재료로서 패각 잔 골재의 사용 가능성을 분석하였다. 패각을 활용한 3D 프린팅 콘크리트는 패각 잔골재와 시멘트 풀 계면 등의 공극 요인으로 일반 콘 크리트 대비 낮은 강도를 가지기 때문에 역학적 성능 평가를 위한 미세구조 특성 분석이 요구된다. 유동성, 출력성 및 적층성을 고려하 여 3D 프린팅 콘크리트의 배합을 선정하였으며, 패각 잔골재를 활용한 3D 프린팅 콘크리트 시편의 물성과 미세구조를 분석하였다. 시편의 물성을 평가하기 위해 3D 프린터로 압축강도와 부착강도 시편을 제작하였고 강도 시험을 진행하였다. 미세구조를 분석하기 위해 고해상도 이미지를 얻을 수 있는 SEM 촬영을 수행하였으며, 히스토그램 기반 상 분리 방법을 적용하여 공극을 분리하였다. 패각 잔골재 종류에 따른 공극률을 확인하고 확률함수를 활용하여 공극 분포 특성을 정량화하였으며, 패각 잔골재의 종류에 따른 시편의 역학적 물성과 미세구조 특성 간의 상관관계를 확인하였다.

PURPOSES : This study was conducted to evaluate the physical properties of the RAP 50 asphalt mixture containing polymer modified rejuvenator and warm-mix additive to improve the recycling rate of RAP and reduce CO2 emission. METHODS : Mix design of Polymer Modified Warm-mix Asphalt Mixture(RAP 50), and Hot Mix Asphalt Mixture(RAP 30) were produced and the properties of asphalt mixture such as Marshall Stability, ITS, Deformation Strength, TSR, and Dynamic Stability were compared between the two asphalt mixtures. RESULTS : The RAP 50 asphalt mixture showed superior or similar performances compared to the RAP 30 asphalt mixture in all the tests conducted. The results of the Marshall stability and dynamic stability in particular were 13,045N and 3,826 pass/mm, which were 11.37% and 76.7% greater than the RAP 30 asphalt mixture, which indicated that high plastic deformation resistance may be expected. CONCLUSIONS : The results obtained from laboratory tests on the two types of mixtures indicated that the use of polymer modified rejuvenator and warm-mix additive not only allows to increase the proportion of RAP but also improves its properties under lower temperature condition than RAP 30 asphalt mixture. Additionally, it was confirmed that plastic deformation resistance was high and moisture resistance and crack resistance were improved for a RAP 50 asphalt mixture.

Asphalt concrete, which is used as a road base material, accounts for >90% of a road pavement. A huge amount of waste concrete and waste asphalt concrete aggregates are generated. Recently, carbon neutrality is promoted across all industries for sustainability. Therefore, to achieve carbon neutrality in the asphalt concrete industry, waste asphalt concrete aggregates should be recycled. Additionally, road base materials are prepared using additives to ensure structural stability, durability, and economic efficiency. In this study, recycled asphalt concrete aggregates were used to evaluate the physical properties of road base materials according to the type of polymer additive and mixing method, and the applicability of road base each material was evaluated. Results showed that when the acrylate-based polymer additive was mixed, the uniaxial compressive strength was 30% higher. Furthermore, the compressive strength of the split mix was improved by ~29% compared to the total mix.

The asphalt concrete industry, accounting for >90% of road pavement, is a crucial contributor to construction waste. This study focuses on the recycling of asphalt concrete recycled aggregates, which currently exhibits a low rate. We investigated the application of these aggregates, combined with hardener and mixing water, in the development of ecofriendly road base materials using circular aggregates. Results revealed that the 13-mm asphalt concrete recycled aggregates met all quality standards. However, the 25-mm aggregates did not conform to the reclaimed asphalt content standard; however, they met other quality standards. Moreover, the experimental results for the hardener and mixing water indicated compliance with all quality standards.

Conventional aquaculture faces declining productivity, shifting to recirculating aquaculture system (RAS), known for minimizing water usage and maintaining consistent water temperatures for year-round fish growth. Rainbow trout (Oncorhynchus mykiss), a globally important cold-water species and the third most farmed fish in inland waters of Korea, valued for its fecundity and rapid growth. Dissolved oxygen, an important environmental factor affecting fish production and economics, highlights the need for smart aquaculture practices. Since 2018, the rise of intelligent aquaculture platforms, incorporating information and communications technology (ICT), emphasizes the essential role of RAS implementation. This eight-week study aimed to determine the optimal dissolved oxygen concentration for rainbow trout in RAS, utilizing a device for continuous monitoring, control and record. Dissolved oxygen concentrations were set at 5-6 mg/L, 9-10 mg/L, 14-15 mg/L and 17-18 mg/L. The growth rate significantly decreased at 5-6 mg/L, with no significant differences in other experimental groups. In hematological analysis, growth hormone (GH) was significantly highest at 5-6 mg/L, followed by 9-10 mg/L while Insulin-like growth factor-1 (IGF-1) was significantly lowest at 5-6 mg/L. In conclusion, the optimal dissolved oxygen concentration for rainbow trout in RAS is approximately 9-10 mg/L. Higher concentrations do not contribute to further growth or profitability.

The spectrum of this study was research on the closed hydroponic cultivation of netted melons (Cucumis melo L.) using coir substrate, analyzing the impact of this cultivation method on melon yield, fruit quality, and the efficiency of water and nutrient usage. The experimental results showed that the average fruit weight of the melons grown in a closed system was 71.4 g higher than that of the open system, and the fruit width was on average 0.2 cm larger, showing a statistically significant difference. However, there was no difference in the average sugar content of the fruit flesh and height. Although there is no substantial commercial difference, it is conjectured that the change in the macronutrients ratio in the irrigation has played a role in the statistically significant increase in fruit weight, which is attributed to changes in the crops' nutrient uptake concentrations. This necessitates further research for a more comprehensive understanding. In terms of the productivity of irrigation required to produce the fruit, applying the closed system resulted in an increase of 7.6 kg/ton compared to the open system, saving 31.6% of water resources. Additionally, in terms of nutrients, cultivating in a closed system allowed for savings of approximately 59, 25, 55, 83, 76, and 87% of N, P, K, Ca, Mg, and S, respectively, throughout the entire cultivation period. As the drainage was reused, the ratios of NO3 - and Ca2+ increased up to a maximum of 9.6 and 9.1%, respectively, while the ratios of other ions gradually decreased. In summary, these results suggest that closed hydroponic cultivation can effectively optimize the use of water and fertilizer while maintaining excellent fruit quality in melon cultivation.