241 research outputs found

    Distribution Aligned Diffusion and Prototype-guided network for Unsupervised Domain Adaptive Segmentation

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    The Diffusion Probabilistic Model (DPM) has emerged as a highly effective generative model in the field of computer vision. Its intermediate latent vectors offer rich semantic information, making it an attractive option for various downstream tasks such as segmentation and detection. In order to explore its potential further, we have taken a step forward and considered a more complex scenario in the medical image domain, specifically, under an unsupervised adaptation condition. To this end, we propose a Diffusion-based and Prototype-guided network (DP-Net) for unsupervised domain adaptive segmentation. Concretely, our DP-Net consists of two stages: 1) Distribution Aligned Diffusion (DADiff), which involves training a domain discriminator to minimize the difference between the intermediate features generated by the DPM, thereby aligning the inter-domain distribution; and 2) Prototype-guided Consistency Learning (PCL), which utilizes feature centroids as prototypes and applies a prototype-guided loss to ensure that the segmentor learns consistent content from both source and target domains. Our approach is evaluated on fundus datasets through a series of experiments, which demonstrate that the performance of the proposed method is reliable and outperforms state-of-the-art methods. Our work presents a promising direction for using DPM in complex medical image scenarios, opening up new possibilities for further research in medical imaging

    Research on Construction Project Management Strategy Based on EPC General Contracting

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    At present, the rapid development of urban economy in our country and the rise of the construction industry make the contract management model more specialized and standardized. Among them, EPC is a common type of project general contracting mode, which can be divided into design, procurement, construction and other modules according to the requirements and actual conditions of project construction. When carrying out project management of construction projects, the use of EPC general contracting mode can achieve good management results. Therefore, from the perspective of EPC general contracting, this paper discusses the relevant countermeasures of construction project management, aiming to realize the unified and standardizing management of all aspects of engineering construction and improving the level of project management

    Research on control methods of roof radiant cooling system

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    Taking the capillary ceiling radiation air conditioning system in radiation cooling Laboratory of comprehensive experimental building in Shandong Jianzhu University as an example, research the two different control methods which are room temperature control and water temperature control. The roof cooling model was established by using TRNSYS simulation software, two typical summer days were selected to explore the stability of the room temperature and the supply and return water temperature, research the comfort of human body and system energy consumption under two control methods. The results show that the indoor temperature of the two control methods can be stable at the design temperature of 27℃ under outdoor high temperature environment in summer. When the maximum outdoor temperature does not exceed 30℃, the temperature stability of the room temperature control method is better, the comfort of the two control methods can meet the requirements, but the water temperature control method is more comfortable. The room temperature control method is 20% ~ 25% energy saving than the water temperature control method in the two typical selected days, and is 40.5% energy saving in the whole cooling season

    Improving Strength and Microstructure of SiC Reticulated Porous Ceramic through In-Situ Generation of SiC Whiskers within Hollow Voids

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    SiC Reticulated Porous Ceramic with Excellent Strength and High-Density Ceramic Struts Was Successfully Prepared using the Polymer Replica Method, Followed by Pressureless Sintering under a Buried Charcoal Atmosphere. First, a Polyurethane (PU) Template Was Coated with a Si Slurry and Then a SiC-Containing Slurry, and Subsequently Heated under the Buried Charcoal Atmosphere. to Ensure Excellent Coating Ability of the Slurries, the Viscosity, Thixotropy, and Yield Stresses of the Si Slurry Were Optimized by Adjusting the Content of the Thickening Agent. during Heating, Si in the Coating Layer Reacted with the Residual C and CO Gas from the PU Template and Buried Charcoal, Forming SiC Whiskers that Filled Hollow Voids within the SiC Struts. Additionally, Catalyst Ferric Nitrate Was Added to the Si Slurry to Promote the Generation and Growth of SiC Whiskers. as a Result, When Compared to the Untreated SiC Reticulated Porous Ceramic, the SiC Reticulated Porous Ceramic Pre-Coated with Si Layers Exhibited Significant Improvements in Mechanical Strength and Thermal Shock Resistance, Despite Minor Differences in Porosity. Furthermore, an Industrial Test Conducted in the Copper Smelting Industry Showed that the Structure of SiC Reticulated Porous Ceramic, Prepared in This Study and Used as Filters, Remained Intact Even after 7 Days of Continuous Use. Meanwhile, a Significant Number of Inclusions Was Adhered to the Surfaces of the Filters. Therefore, the Processes Combined with In-Situ Generation of SiC Whiskers is an Ideal and Low-Cost Method for Fabricating SiC Filters with Excellent Properties

    Research on the cooling characteristics in building interior zones using displacement ventilation system

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    The outdoor low temperature fresh air can be used as a free cold source to eliminate waste heat for the building interior zones during the transition season and winter. This paper takes a project in Hunan as an example, and the project building interior zones is 25m×7m×3.9m(L×W×H). Using Fluent software to simulate the temperature field and velocity field both the interior and exterior zones of the engineering offices. The simulation results show that using the displacement ventilation system to take the outdoor air into inner rooms not only cooling but also improving the air quality and adding comfort. According to the simulation results and outdoor air dry bulb temperature and enthalpy values, the h − d diagram is divided into three air conditioning conditions (summer, winter, transition season), and three different operation adjustment methods have been proposed corresponding to each air conditioning condition, which will reduce the energy consumption of air conditioning system

    The cross-level influence of ethical leadership on employee’s OCBE: a two-wave study based on the social identity approach

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    The importance of organizational citizenship behavior for the environment (OCBE) has received increasing attention in recent years because organizations face increasing pressure from environmental deterioration. The purpose of this study is to use social identity theory to construct a cross-level theoretical model of ethical leadership on OCBE, and to explore the cross-level influential mechanisms of ethical leadership on OCBE. Data collection was conducted via a two-wave distribution of leader-employee paired questionnaires in 20 manufacturing companies in China. In the first wave, data about OCBE and team environmental atmosphere were collected from leaders. Subsequently, 2 months later, we conducted the second wave of data collection when data about ethical leadership and leader identity were obtained from their employees. The results showed that at the individual level, ethical leadership has a significant positive impact on employees’ OCBE, and such relationship is partially mediated by employees’ leader identity and positively moderated by team environmental atmosphere across levels. At the team level, ethical leadership has a significant positive impact on employees’ OCBE, and such relationship is completely mediated by team environmental atmosphere. This study investigates the cross-level influential mechanism of ethical leadership on OCBE in China and provides theoretical guidance for enterprises to promote OCBE effectively

    Diagnostic Value of CT-detected Extramural Vessel Invasion in Lymph Node Metastasis of Gastric Cancer

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    Objective: To investigate the diagnostic value of extramural vessel invasion (EMVI) in multidetector row computed tomography (MDCT) of lymph node metastasis of gastric cancer. Methods: A total of 105 patients with pathologically confirmed gastric cancer treated at our hospital between January 2020 and June 2022 were retrospectively collected. All patients underwent radical gastrectomy and D2 lymph node dissection within 2 weeks after the CT scan. The EMVI status of gastric cancer was evaluated on portal-phase MDCT images using a 5-point scale. According to the pathological status of lymph node metastasis, the patients were divided into lymph node and non-lymph node metastasis groups, and their clinicopathologic features were compared. We then performed a multivariate logistic regression analysis of lymph node metastasis in gastric cancer. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of CT-detected EMVI (ctEMVI) in lymph node metastasis, and the diagnostic values of ctEMVI and lymph node short diameter in lymph node metastasis were compared. Results: In the lymph node metastasis group, lymphovascular invasion, tumor size (>5 cm), ctEMVI positivity, and CT metastatic lymph node positivity accounted for 60.9% (n=39), 64.1% (n=41), 79.7% (n=51), and 56.2% (n=36) of cases, respectively. In the non-metastatic group, lymphovascular invasion, tumor size (>5 cm), ctEMVI positivity, and CT metastatic lymph node positivity accounted for 21.9% (n=9), 24.4% (n=10), 21.9% (n=9), and 19.5% (n=8), respectively. The intergroup difference was statistically significant. The multivariate logistic regression analysis showed that ctEMVI was an independent factor of lymph node metastasis. The ROC curve showed that the area under the curve of ctEMVI for diagnosing lymph node metastasis was 0.854. The sensitivity and accuracy of ctEMVI were superior to those of lymph node short diameter in the diagnosis of lymph node metastasis. Conclusion: This study found that ctEMVI was an independent factor and of great value in the diagnosis of lymph node metastasis

    Sparse general non-negative matrix factorization based on left semi-tensor product

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    The dimension reduction of large scale high-dimensional data is a challenging task, especially the dimension reduction of face data and the accuracy increment of face recognition in the large scale face recognition system, which may cause large storage space and long recognition time. In order to further reduce the recognition time and the storage space in the large scale face recognition systems, on the basis of the general non-negative matrix factorization based on left semi-tensor (GNMFL) without dimension matching constraints proposed in our previous work, we propose a sparse GNMFL/L (SGNMFL/L) to decompose a large number of face data sets in the large scale face recognition systems, which makes the decomposed base matrix sparser and suppresses the decomposed coefficient matrix. Therefore, the dimension of the basis matrix and the coefficient matrix can be further reduced. Two sets of experiments are conducted to show the effectiveness of the proposed SGNMFL/L on two databases. The experiments are mainly designed to verify the effects of two hyper-parameters on the sparseness of basis matrix factorized by SGNMFL/L, compare the performance of the conventional NMF, sparse NMF (SNMF), GNMFL, and the proposed SGNMFL/L in terms of storage space and time efficiency, and compare their face recognition accuracies with different noises. Both the theoretical derivation and the experimental results show that the proposed SGNMF/L can effectively save the storage space and reduce the computation time while achieving high recognition accuracy and has strong robustness
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