Hong-Seok Yang

Separation logic [Reynolds, J. C., Intuitionistic reasoning about shared mutable data structure, in: J. Davies, B. Roscoe and J. Woodcock, editors, Millennial Perspectives in Computer Science, Palgrave, 2000 pp. 303–321; Reynolds, J. C., Separation logic: A logic for shared mutable data structures, in: LICS '02: Proceedings of the 17th Annual IEEE Symposium on Logic in Computer Science (2002), pp. 55–74; O'Hearn, P., J. Reynolds and H. Yang, Local reasoning about programs that alter data structu

Reasoning about programs manipulating pointers has been considered as difficult not because of the lack of formalisms for verifying pointer programs, but because of the significant increase in the complexity of proofs in each formalism over an informal argument. Recently, there has been noticeable development in handling the complexity by exploiting locality of memory access within a code fragment. Reynolds introduced a pointer logic based on a "spatial" interpretation, where d

Trees in urban spaces surrounded by buildings may be effective in dispersing sound energy, and this could affect sound level distribution and street canyon reverberation. To quantify this effect of trees with a view to including it in numerical predictions, this paper examines sound scattering from a single tree in open field by means of reverberation time (RT). Five trees of different species and crown sizes were considered. The influence of ground condition, receiver height, crown size and sha

Shape analysis is a precise form of pointer analysis, which can be used to verify deep properties of data structures such as whether or not they are cyclic, whether they are nested, etc. Shape analyses are also expensive, and the tremendous number of abstract states they generate is an impediment to their use in verification of sizeable programs. We start with an analysis that is able to analyze programs up to 1000 lines manipulating complex, nested structures, and progressively improve it until

Many apartment complexes in Korea feature underground car parks releasing more of the landscape for residents' leisure, rest, or conversation. The acoustic characteristics of these outdoor spaces can therefore make a significant contribution to the overall quality of the environment. This experimental study investigated the acoustic characteristics of outdoor spaces surrounded by multi-storey apartment buildings. In-situ measurements in three positions were carried out to evaluate the acoustic p

In Korea, water supply and drainage noises result in one of the main noise complaints because more than 50% of people reside in multi-residential buildings. In this study, a series of field measurements were therefore carried out to examine the current noise situation. The noise levels were measured in the bathrooms of the upper and lower floors, as well as in habitable rooms. The measurement results for the bathrooms of the lower floor (N = 113) are 47.8 dBA (water closet), 42.7 dBA (basin), an

This study explores the effects of natural and sustainable materials including vegetation, green roof systems and green walls on outdoor noise control in urban areas. The concept of this study starts with a hypothesis that well-planned use of the natural materials on building and urban surfaces can achieve useful reductions in noise levels and reverberation in urban spaces. Firstly, this study examines random-incidence absorption and scattering coefficients of vegetation through a series of meas