It is a general phenomenon for manufacturers to provide vertically differentiated product line for more profit through improved market coverage. For such manufacturers, the compatibility between vertically differentiated products is an important decision issue. Some manufacturers provide full compatibility between high and low version products, whereas some provide only downward compatibility for the purpose of recommending high version product. In this study, the two representative compatibility strategies, full or downward, between vertically differentiated products produced by a single manufacturer are analyzed, especially under network externality and in the viewpoint of profit maximization. To do this we used a market model which captures the basic essence of vertical differentiation and network externality. Based on the proposed market model, the profit maximizing solutions are derived and numerically analyzed. The results can be summarized as follows : (1) Regardless of compatibility strategy, under network externality, vertical differentiation is always advantageous in terms of profit. (2) The full compatibility strategy is shown to be the most advantageous in terms of profit. In addition, it is necessary to make quality difference between differentiated products as wide as possible to maximize profit. (3) To gradually drive low version product out of the market and shift the weight pendulum of market to high version product, it is shown that the downward compatibility strategy is essential. Unlike intuition, however, it is also shown that in order to drive low version product out of market, it is necessary to raise the quality of the low version product rather than to lower it.

Maritime transportation plays a significant role in global economies. Seaports as primal nodes in maritime supply chain are also indispensable in ensuring efficient and effective global trading. On the other hand, seaport inefficiencies have profound influences on the overall performance which can cause congestion, operational disruption, high cost expenses, unnecessary wastes and environmental pollution, which eventually resulting significant financial losses. As a result, business and environmental sustainability will not be achieved. In order to overcome these hindrances, a novel performance model of Lean, Agile, Resilience and Green (LARG) is proposed as management tools for enhancing the business and environmental sustainability in seaport supply chain operations. The compatibility of LARG paradigms in seaport supply chain need to be identified and analysed to achieve the research aim. This paper employed a compatibility analysis for the new LARG paradigm for enhancing seaport supply chain practices. In this analysis, all potential paradigms are thoroughly reviewed and further validated by the domain experts consisting of academic and industry experts. The result of this paper shows that 17 selected LARG paradigms are compatible with 23 seaport supply chain practices respectively. For future research, the identified paradigms can be further investigated for many purposes such as measuring their influence on seaport supply chain practices and even assessing their applicability. It is worth mentioning that this research outcomes can assist Malaysian seaport practitioners to develop an enhanced management paradigm to boost their performance based on LARG model. Moreover, this model also can be applied globally as it is able to be adapted, revised and adjusted to suit the seaport preferences. As a result, this model able to enhance business capabilities, operational efficiencies and competitive advantages of seaport supply chain operations globally.

A strain compatibility method is based on the strain compatibility approach proposed by AISC (American Institute of Steel Construction, Inc.). The strain compatibility method assumes a linear strain of all the members. After that, set up the equilibrium equations of the state of stress in each component for calculating the location of the neutral axis of the cross-section in the presence. In this study, the reinforced concrete simple beam is analyzed by strain compatibility method for calculating the neutral axis and the bending moment. And then, a variation of neutral axis of the reinforced concrete simple beam is measured.