Increasingly, companies’ attempts to become more sustainable are framed in terms of transitioning towards sustainable business models (SBMs), whereby central logic of how the company offers value to customers is challenged (Yang & Evans, 2019). This transition requires companies to rethink the way value and resource consumption are coupled in their operations (Pieroni et al., 2019), as well as consider different ways of connecting with customer needs (Laukkanen & Tura, 2020).

단순 박스모델을 이용하여 2005~2006년 마산만의 담수 유량, 염분, 영양염, COD등 물질 수지를 산정하였다. 담수수지 계산 결과 계절별로 307.4×103~1,210×103m3/day로 이 시기에는 5 월이 가장 높았다. 하천과 생활하수에 의한 DIP과 DIN의 유입flux는 각각 410.8~795.7kg/day 및 4081.4~6525.3kg/day 범위로 마산만 내부에서 질소의 축적이 예상된다. 순 기초생산(net primary production)은 연 평균 0.028mol/m2/day로 14.4~517.8mgC/m2/day의 범위로 분포하였으며, 평균 330.7mgC/m2/day 였다. 해저 퇴적물로부터의 영양염 공급을 100% 제거할 경우 COD 농도는 2.79mg/L 에서 2.20mg/L로 감소하여 COD의 21.0%의 제거 효과가 있는 것으로 나타났다.

Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate these factors by application of multiple measurements. For the total duration of 30 days, daily indoor and outdoor NO2 concentrations were measured in 30 houses in Brisbane, Australia, and for 21 days in 40 houses in Seoul, Korea, respectively. Using a box model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the ventilation and source strength were estimated. In Brisbane, the penetration factors were 0.59±0.14 and they were unaffected by the presence of a gas range. During sampling period, geometric mean of natural ventilation was estimated to be 1.10±1.51 ACH, assuming a residential NO2 decay rate of 0.8 hr-1 in Brisbane. In Seoul, natural ventilation was 1.15±1.73 ACH with residential NO2 decay rate of 0.94 hr-1. Source strength of NO2 in the houses with gas range (12.7±9.8 ppb/hr) were significantly higher than those in houses with an electric range (2.8±2.6 ppb/hr) in Brisbane. In Seoul, source strength in the houses with gas range were 16.8±8.2 ppb/hr. Conclusively, indoor air quality using box model by mass balance was effectively characterized.