Spatial stochastic programming model for timber and core area management under risk of stand-replacing fire, A

2012 Fall.Includes bibliographical references.Forest harvest scheduling has been modeled using deterministic and stochastic programming models. Past models seldom address explicit spatial forest management concerns under the influence of natural disturbances. In this research study, we employ multistage full recourse stochastic programming models to explore the challenges and advantages of building spatial optimization models that account for the influences of random stand-replacing fires. Our exploratory test models simultaneously consider timber harvest and mature forest core area objectives. Each model run reports first-period harvesting decisions for each stand based on a sample set of random fire. We integrate multiple model runs to evaluate the persistence of period-one solutions under the influence of stochastic fires. Follow-up simulations were used to support multiple comparisons of different candidate forest management alternatives for the first time period. Test case results indicate that integrating the occurrence of stand-replacing fire into forest harvest scheduling models could improve the quality of long-term spatially explicit forest plans

A secure image steganography based on JND model

Minimizing distortion produced by embedding process is very important to improve the security of hidden message and maintain the high visual quality of stego images. To achieve these objectives, an effective strategy is to perform pixel selection which is well-known as a channel selection rule. In this approach, a pixel associated with the smallest image degradation is chosen to carry secret bits. From these facts, in this paper, a new secure channel selection rule for digital images in spatial domain is designed and proposed. In this new approach, the modified matrix embedding method is utilized as data hiding method because it introduces more than one embedding change to be performed. This enables us to select a suitable pixel to embed message bits with less degradation yielded in a stego-image. In pixel selection of the proposed method, a just noticeable difference value and gradient value of a considering pixel are employed together. The experimental results (which were conducted on 10,000 uncompressed images) indicate that stego images of the proposed approach achieve a higher perceptual quality and security than those of the stego-images created by the previous approaches

The Organizational Culture Strategy SMEs During Economic Crises

The importance of organizational culture in the operation and performance of businesses has been widely acknowledged, but there is inconsistency in findings about the impact of culture on organizational performance across studies. This study aimed to achieve two objectives: first, to establish the relationship between the quality of accounting information systems (AIS), organizational culture, and the financial performance of small and medium enterprises (SMEs) in Vietnam; and second, to survey the organizational culture strategy of Vietnamese SMEs in the context of economic crises. The study survey was conducted in May 2023 and involved 242 SMEs in Vietnam. The research model was tested using Smart PLS. The results suggest that AIS has a positive relationship with both organizational culture and the financial performance of SMEs. However, organizational culture only affects financial performance related to organizational adaptability during a crisis. Moreover, a flexible, external adaptation, and balanced cultural approach strategy has a significant impact on the financial performance of SMEs. During a crisis, managers expect employees to adapt in order to achieve strategic goals and plans while simultaneously balancing stability, engagement, and employee satisfaction to achieve organizational effectiveness. Doi: 10.28991/ESJ-2023-07-06-015 Full Text: PD

The Influence of Factors on the Demand for Performance Auditing in the Public Sector

Performance audits (PA) are becoming essential in supreme audit institutions (SAIs). This study aims to explain why developing countries need to expand the function of PA and to explore and measure the impact of each factor on the need to develop PA in Vietnam. The research combines qualitative (group discussion) and quantitative methods by surveying 157 state auditors of the State Audit of Vietnam (SAV). Data is processed through SmartPLS 4.0.8.5 to verify the measurement and linear structure models. The results of the statistical analysis also show that all three factors have an impact on the development of PA, including (i) the degree of public governance reform, (ii) the accountability of SAV, and (iii) occupational influence. Besides, the model test results show that, from the perspective of SAV, the need to improve performance is higher than accountability. Public governance reform factors, external support, and SAI accountability contribute to enhancing the value of PA. The findings of this study complement the audit theory on three fronts: (i) PA will become more important when pursuing the goal of increasing accountability rather than improving performance; (ii) PA continues to evolve to adapt to social changes; and (iii) additional empirical evidence demonstrating that countries with low levels of transparency and accountability and inconsistent legal systems have higher audit “demand” but low supply of PA. This study proposes a PA development model to: (i) forecast the ability and level of the development audit of each SAI; and (ii) contribute to enhancing the value of PA using the PA topic selection tool. In addition, the developed scale is tested to ensure its reliability and validity. So this scale can be used to survey the needs, feasibility, and expected value that each audit subject brings before and after implementation. Doi: 10.28991/ESJ-2024-08-01-07 Full Text: PD

Vietnam. La arquitectura religiosa contemporánea como un bien escaso

[Abstract] In the 16th century, the first Spanish and Portuguese Dominican missionaries arrived in Southeast Asia, included Vietnam, but only after the first decades of the seventeenth century, Christianity began to take hold and lived through different episodes of the Proclamation of the Christian faith: first it was tolerated and then abandoned by the dynasties, supported by the colonialists, declined in the north by the communists, it expanded in the south under the Republic of Vietnam and stabilized until now after the reunification of the country followed by a long breakage due to political change. Along with this story, sacred architecture was interpreted in various ways to define identities in religious life and faith. However, the most difficult period of religious architecture is not only in the political conflict of the past, but also until now, the time of the economic boom. The change of values as well as the aesthetic system make sacred art and architecture remain a giant wheel stuck in mud.[Resumen] En el siglo XVI, los primeros misioneros dominicos españoles y portugueses llegaron al sudeste asiático, incluso a Vietnam, pero solo después de las primeras décadas del siglo XVII, el cristianismo comenzó a afianzarse y vivió diferentes episodios de la Proclamación de la fe cristiana: primero fue tolerado y luego abandonado por las dinastías, apoyado por los colonialistas, declinado en el al norte por los comunistas, se expandió en el sur bajo la República de Vietnam y se estabilizó hasta ahora después de la reunificación del país seguida de una larga ruptura debido al cambio político. Junto con esta historia, la arquitectura sagrada se interpretó de diversas formas para definir identidades en la vida religiosa y en la fe. Sin embargo, el período más difícil de la arquitectura religiosa no es solo en el conflicto político del pasado, sino también hasta ahora, la época del boom económico. El cambio de valores así como el sistema estético hacen que el arte y la arquitectura sagrados sigan siendo una rueda gigante atascada en el barro

Towards Efficient Communication and Secure Federated Recommendation System via Low-rank Training

Federated Recommendation (FedRec) systems have emerged as a solution to safeguard users' data in response to growing regulatory concerns. However, one of the major challenges in these systems lies in the communication costs that arise from the need to transmit neural network models between user devices and a central server. Prior approaches to these challenges often lead to issues such as computational overheads, model specificity constraints, and compatibility issues with secure aggregation protocols. In response, we propose a novel framework, called Correlated Low-rank Structure (CoLR), which leverages the concept of adjusting lightweight trainable parameters while keeping most parameters frozen. Our approach substantially reduces communication overheads without introducing additional computational burdens. Critically, our framework remains fully compatible with secure aggregation protocols, including the robust use of Homomorphic Encryption. The approach resulted in a reduction of up to 93.75% in payload size, with only an approximate 8% decrease in recommendation performance across datasets. Code for reproducing our experiments can be found at https://github.com/NNHieu/CoLR-FedRec.Comment: 12 pages, 6 figures, 4 table