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This study explores the potential energy surfaces of the S 0 , S 1 and T 1 states using ab initio theory to provide insight into the spectroscopy, photochemistry and reaction dynamics of propanal. Minima associated with the formyl potential energy coordinate in the S 1 and T 1 states are found to be $60 out-of-phase with the S 0 state. Furthermore, the excited states possess a pyramidal formyl carbon atom that leads to a double minimum at AE33 and AE49 for the S 1 and T 1 states, respectively. An exploration of the C-C dissociation coordinate on the T 1 surface, yielding the products CH 3 CH 2 þ CHO, shows that a three-fold potential due to the formyl torsion is still operational, resulting in three unique transition states that lead to dissociation. The lowest energy pathway to dissociation occurs at a barrier height of 4766 cm À1 and the energy of the products is found to be 1017 cm À1 , relative to the T 1 global minimum. Consequently, a reverse barrier of 3749 cm À1 is calculated. Parameters calculated for the lowest energy transition state geometry are distinctly different from structures inferred from experiment, which assumed an isotropic dissociation channel.

Off-Site Construction (OSC) is a new construction method based on factory production. Due to its advantages over traditional methods, such as high productivity, economic efficiency, and excellence in quality, OSC research has actively been conducted worldwide ranging from design and production standardization, transportation method, to construction planning. Thus, to understand what knowledge has been developed to improve the management of OSC projects, this study reviewed OSC papers that focus on improving a specific project management area (e.g., time, cost, and quality) in a specific phase of a project, i.e., “process-level research.” This study found 94 papers with such a focus, out of 222 OSC project management papers published from 1986 to 2018, and assessed the trends of the research with multiple dimensions, including project phases, OSC types, application types, and management areas. Main findings are as follows: (1) process-level research has been increasing fast since 2006. (2) Non-volumetric pre-assembly type contributes the most to the increase of process-level OSC management research. (3) Research focuses vary depending on the application type (e.g., living quality issues for residential, economics issues for non-residential, productivity issues for plant). (4) Wider project management areas (e.g., quality, human resources, risk) have gained attention from OSC papers since 2006. (5) Non-volumetric type gained interests in residential and non-residential buildings, whereas modular type was studied frequently in plants. This study would help project management researchers understand the trends in OSC and plan and conduct future OSC project management research.

A Ab bs st tr ra ac ct tIn the current maintenance system of building, safety inspection and precise safety diagnosis have been applied only for Type 1 and 2 buildings. Considering the fact that middle and small-size buildings take up 99.4% of total buildings, it is necessary to implement safety diagnosis for the buildings to make long lasting buildings. This study suggested improvement methods for adjusting the existing evaluation items to middle and small-size buildings by reviewing the current diagnosis system and a survey. Based on the methods, an improved model, which modified the existing diagnosis model, was developed by applying fuzzy theory. If the improved model of this study is applied on site, the buildings except Type 1 and 2 could be maintained constantly. In the future studies, it is necessary to implement the developed model practically, to strengthen the feasibility of the model.

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