• Transactions on Electrical and Electronic Materials
• /
• v.17 no.6
• /
• pp.311-316
• /
• 2016

Batteries are critical components of electric vehicles and energy storage systems. The connection of a battery to the power grid for charge and discharge greatly affects energy storage. Therefore, an accurate and easy-to-observe battery model should be established to achieve systematic design, simulation, and SOC (state of charge) estimations. In this review, several equivalent circuit models of representative significance are explained, and their respective advantages and disadvantages are compared to determine and outline their reasonable applications to Li-ion batteries. Numerous commonly used model parameter identification principles are summarized as well, and basic model verification methods are briefly introduced for the convenient use of such models.

• Land and Housing Review
• /
• v.6 no.2
• /
• pp.89-99
• /
• 2015

What is a role of the studies on spatial planning of Korean peninsular and its cities in the process of cooperation between and unification of South and North Korea? Where should the basic perspectives be oriented for the process? Can a comprehensive plan of North Korea have practical implications although South-North cooperation does not get into its stride? If it can, which contents should the plan cover? This study aims to contemplate these issues and to suggest a preliminary land development approach of North Korea, which would contribute academic and practical debates on the issues, at this juncture of the cascade of studies on spatial planning in North Korea. It assume South-North relation would evolve from 'reconciliation and cooperation' and 'confederation' into 'unification' of South and North Korea which is based on the official plan of South Korea. We suggest, as the basic perspectives of development approach, cooperation(or co-evolution), future-oriented sustainability, and parallel development of industry and physical infrastructure. The development potential of North Korea is explained by detail fields and sub-regions, which is used to analyse SWOT and to subsequently extract the basic directions(vision and strategies) of North Korea development. These directions are followed by the spatial structure plan to improve North Korea using the potential of the regions. Based on the plan, the development directions of detail fields are suggested.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.6
• /
• pp.44-56
• /
• 2019

Recently, the paradigm of SOC investment has shifted from new construction to maintenance. This shift became more important for the highway system because it is as one of the most important SOC. In Korea, highway maintenance costs are about 20% of the total annual highway construction budget, which is about two-thirds of developed countries. In addition, establishing standardized guidelines for the highway maintenance operation is not in place. Therefore, in order for domestic road construction and maintenance technology to secure competitiveness in the global construction market, it is urgent to improve the management capacity for maintenance as well as the technology and management capacity. This study examines highway maintenance practices in OECD countries such as North America, Europe, Australia, New Zealand, and Japan to identify core elements of highway maintenance practice. It is imperative to establish a comprehensive management system based upon asset management principle. Even if the budget for the highway construction is reduced, investment in maintenance needs to be maintained.