A Comparative Study of Dry Ports in East Africa and China

The period between 1970s and 1990s witnessed a number of global changes. Significant ones were; liberalization of trade, deregulation of many economies, and emergence of economic integrations of countries and regions. These changes in addition to innovation and advancement of ICT impacted on trade and the shipping sector. Thevolume of trade, the cargo transported by sea, and the number of shipping vessels increased thus putting pressure on existing sea ports. Dry ports were introduced as a way of accessing the hinterland and also reduce the pressure on the bottle necked, congested and inefficient sea ports. Theadoption of dry port concept began in Europe and North America, followed by Asia, South America and then Africa. This trend created the need to conduct studies about this sector. This paper therefore tries to compare historical perspectives, developing mode, and management model of the dry ports sector in China, a high income developing country, under a socialist system, with advanced shipping infrastructure, against the East African region, which is characterized with low income countries, free market policies, anda largely less developed shipping infrastructure. The paper also presents discussions on the pros and cons of both systems from which, conclusions and recommendations are drawn to support future studies and policy formulation. This paper not only serves the purpose of contributing to existing academic knowledge in respect to dry ports, but it also gives the policy makers and practitioners in the logistics and trade sectors a chance to compare the practices in the two developing regions and apply what is suitable for a particular case. Keywords: Comparative study, Dry Ports, East Africa, Chin

Nano-crystalline porous tin oxide film for carbon monoxide sensing

A tin oxide sol is deposited on platinum electrodes (12) of a sensor (10). The sol is calcined at a temperature of 500 to 800.degree. C. to produce a thin film of tin oxide with a thickness of about 150 nm to 2 .mu. and having a nano-crystalline structure with good stability. The sensor rapidly detects reducing gases, such as carbon monoxide, or hydrocarbons and organic vapors. Sensors using films calcined at around 700.degree. C. have high carbon monoxide selectivity with a response time of around 4 minutes and a recovery time of 1 minute, and therefore provide good detection systems for detection of trace amounts of pollutants such as toxic and flammable gases in homes, industrial settings, and hospitals

Odd symplectic/orthogonal skew Schur functions

Using vertex operators we construct odd symplectic Schur functions $sp_\lambda(\mathbf{x}^{\pm};z)$ and odd orthogonal Schur functions $o_\lambda(\mathbf{x}^{\pm};z)$ with parameter $z$ as well as their skew versions. We show that these two families of symmetric functions generalize the odd symplectic/orthogonal Schur functions and provide formulas in terms of the even symplectic/orthogonal Schur functions. We also derive the Gelfand-Tsetlin presentations and the Jacobi-Trudi formulas for both the skew versions. Interpretations of $sp_{\lambda/\mu}(\mathbf{x}^{\pm};\mathbf{z})$ and $o_{\lambda/\mu}(\mathbf{x}^{\pm};\mathbf{z})$ with parameters $\mathbf{z}=(z_1,\dots,z_k)$ as intermediate characters are also discussed.Comment: 14pp, no figure

HoMM: Higher-order Moment Matching for Unsupervised Domain Adaptation

Minimizing the discrepancy of feature distributions between different domains is one of the most promising directions in unsupervised domain adaptation. From the perspective of distribution matching, most existing discrepancy-based methods are designed to match the second-order or lower statistics, which however, have limited expression of statistical characteristic for non-Gaussian distributions. In this work, we explore the benefits of using higher-order statistics (mainly refer to third-order and fourth-order statistics) for domain matching. We propose a Higher-order Moment Matching (HoMM) method, and further extend the HoMM into reproducing kernel Hilbert spaces (RKHS). In particular, our proposed HoMM can perform arbitrary-order moment tensor matching, we show that the first-order HoMM is equivalent to Maximum Mean Discrepancy (MMD) and the second-order HoMM is equivalent to Correlation Alignment (CORAL). Moreover, the third-order and the fourth-order moment tensor matching are expected to perform comprehensive domain alignment as higher-order statistics can approximate more complex, non-Gaussian distributions. Besides, we also exploit the pseudo-labeled target samples to learn discriminative representations in the target domain, which further improves the transfer performance. Extensive experiments are conducted, showing that our proposed HoMM consistently outperforms the existing moment matching methods by a large margin. Codes are available at \url{https://github.com/chenchao666/HoMM-Master}Comment: Accept by AAAI-2020, codes are available at https://github.com/chenchao666/HoMM-Maste

Optimization on the container loading sequence based on hybrid dynamic programming

Retrieving export containers from a container yard is an important part of the ship loading process during which arranging the retrieving sequence to enhance port efficiency has become a vital issue. This paper presents a twophase hybrid dynamic algorithm aiming at obtaining an optimized container loading sequence for a crane to retrieve all the containers from the yard to the ship. The optimization goal is to minimize the number of relocation operations which has a direct impact upon container loading operation efficiency. The two phases of the proposed dynamic algorithms are designed as follows: at the first phase, a heuristic algorithm is developed to retrieve the containers subset which needs no relocation and may be loaded directly onto the ship; at the second phase, a dynamic programming with heuristic rules is applied to solve the loading sequence problem for the rest of the containers. Numerical experiments showed the effectiveness and practicability of the model and the algorithm by comparing with the loading proposals from an existing research and actual rules respectively. First published online: 14 Jan 201

Integrated Assessment of Nitrogen Resource Management in Songyuan,China

Due to the extensive use of nitrogen fertilizer in China, excess nitrogen has been discharged into groundwater, rivers, and the air, contributing to environmental problems such as eutrophication and the generation of greenhouse gases. In this research, an inter-industry analysis method and linear programming were used to design and assess integrated nitrogen resource management policies for Songyuan city, China. An inter-industry model was constructed using nitrogen mass balance. Based on our simulation results, we suggest optimal policies of integrated nitrogen resource management to support sustainable economic development in Songyuan city. We propose to increase organic fertilizer use instead of chemical fertilizer application within 4% along with installing a maximum of 16 units of biomass methane fermentation/power generation technologies in the city. These comprehensive policies would reduce nitrogen discharges by 513 thousand tons and create a net social benefit of 1,453 million yuan, accounting for about 1.5% of the region’s gross regional product for 2010. The Chinese government should focus on efficient use of nitrogen resources in its agriculture and livestock industries by reducing chemical fertilizer application and increasing organic fertilizer