Hoyoung Jeong

A case-controlled, retrospective, comparative study on the use of biodegradable synthetic polyurethane foam versus polyvinyl acetate sponge after nasal fracture reduction.

One of the most frequently used packing materials in closed reduction of a nasal bone fracture is the hydroxylated polyvinyl acetate sponge (PVAS; Merocel(®)); however this may cause synechia, epistaxis, and pain. Synthetic polyurethane foam (SPF; Nasopore(®) Forte) has recently been used in septoplasty to prevent synechia or restenosis and haematoma formation. The purpose of this study was to compare the effects of PVAS and SPF on postoperative appearance and discomfort following the reduction of nasal bone fractures. We retrospectively reviewed all patient questionnaires and medical histories, and clinical photographs and computed tomography scans obtained before and after surgery. Outcomes were assessed using the Global Aesthetic Improvement Scale (GAIS) score and visual analogue scale (VAS) scores, which were used to assess discomfort during the 6-month follow-up period. Postoperatively, there was no statistically significant difference in the GAIS for the two packing materials (P > 0.05). Postoperative epistaxis was observed at a significantly lower rate in the SPF group than in the PVAS group, whereas anterior rhinorrhea and posterior nasal drip occurred at significantly higher rates following removal of packing in the SPF group (P < 0.05). The results of this study suggest that synthetic dissolvable polyurethane may be a reliable alternative material for nasal packing and postoperative management following the reduction of nasal bone fractures.

On-site Safety Management Using Image Processing and Fuzzy Inference

Construction is generally conducted in highly changeable site conditions due to operation of machinery, transfer of materials, moving workers, and changing progress status. Such dynamic characteristics can always lend themselves to the potential for safety accidents. However, it is not easy to have a generalized safety management system that can universally apply to every job site. Although there are some guidelines for safety management, their application to a construction site has to be tailored to satisfy the unique nature of the particular project. Based on the good understanding of the particular site, effective and appropriate safety management process should be derived for workers to be protected from potential dangers of the site. This paper presents an on-site safety management methodology based on image processing and fuzzy inference. Image processing is used to extract spatial information of workers; fuzzy inference is then used to provide the workers a proper level of safety warning based on the spatial information. Contextual site information, such as equipment operations and density of workers, also constitute the on-site safety management methodology. The proposed methodology is expected to provide a safer working environment for construction workers, through its capability to easily customize the safety management system for a construction site.

Algorithm for Economic Assessment of Infrastructure Adaptation to Climate Change

Climate change, along with the increase of severe weathers and natural disasters, is becoming an important factor to consider for infrastructure investments. To adapt infrastructure to the effects of climate change, new design, construction, or rehabilitation methods – so-called adaptation methods – can be deployed. However, it is crucial to understand the impact of adaptation methods on infrastructure before they are actually implemented. When the economic benefit and cost are clear, asset managers can confidently make informed decisions about the priority of investment alternatives. This paper proposes an integrated algorithm to assess the benefit and cost of adaptation methods. The “integrated” aspect of the algorithm is derived from the fact that climate change effects on infrastructure can be divided into two categories. One is sudden extreme weather events caused by climate change; this sudden event leads to swift and disruptive damages to infrastructure. The other is a gradual climate change of which effects are shown over a long period of time. The algorithm combines the two different aspects of climate change to estimate the net benefit of adaption methods in an integrated manner. Future climate scenarios are first assumed and their input variables are determined for further procedures. With extreme events such as supertyphoon, the procedure for sudden failure of infrastructure is used to estimate the cost and benefit of the rehabilitation effort. Maintenance cost under gradual climate change is also estimated with the climate change adjusted deterioration curve for the infrastructure of interest. Finally, the above three steps are repeated for each year to estimate the life cycle cost infrastructure adaptation to climate change for the comparison of the costs with and without adopting the adaptation method.

Prediction of Flexible Pavement Deterioration in Relation to Climate Change Using Fuzzy Logic

AbstractAn understanding of the impacts of climate change on infrastructure is important in the context of reducing future socioeconomic losses. Previous research has introduced models based on emp...

Valuation of Adaptation Technology to Climate Change Based on Target Classification

Increase of unpredictable and severe climate events has led to development of technologies for climate change adaptation. Types of adaptation technologies for climate change vary in terms of technological characteristics and the range of their adaptation impact as well. For accurate economic assessment, this paper presents a method to value adaptation technologies based on classification of the target. In this study, the target is classified into two groups: 1) a single structure and 2) a range of area. For a single structure, adaptation technology is focused on the specific infrastructure subject to the climate change. For a range of area, the local region is the focus to consider climate events such as flood, landslide, and sea level rise. These two classes of damages are estimated in two valuation modules: one for extreme climate change and the other for gradual climate change. Climate change scenarios with and without the adaptation technology are used to determine the total value of the adaptation technology.