본 연구는 낙엽활엽수종인 이팝나무(Chionanthus retusa) 잎의 흡음 성능을 평가하고자 하였다. 잎을 주재료로 하여 재료의 크기와 두께 및 건조 조건을 달리해 흡음재를 제조하였다. 중간형 측정관(100㎐-3200㎐)을 적용한 관내법(Impedance tube method)을 이용하여 흡음율을 측정하였 다. 총 18개의 조건에서 측정된 흡음율을 분석하였다. 기건엽 조건(MC 13.92%)과 생엽 조건(MC 162.04%)의 흡음율은 두께가 증가함에 따라 크게 향상되었다. 흡음율은 밀도의 증가에 비례하는데, 부피당 밀도가 더 높은 생엽조건의 두께별 흡음율이 더 높게 나타났다. 생엽 조건군에서 크기 0.5 × 0.5㎠의 2.50㎝ 두께에서 평균 흡음율은 0.643으로 가장 높게 나타났으며, 각 시험처리 조건별 흡음재의 주파수 대역별 흡음율은 기건엽 조건의 두께 1.75㎝에서 가장 높게 나타났다. 이상의 연구결과로부터 전반적인 흡음율은 1000㎐ 이상의 대역에서 더 높은 성능을 보였다.

Smart phones have brought rapid changes in this competitive world. Smart phone application developers are trying their best to consider the customer requirements in the most efficient way while considering all its attributes. However smart phone service quality has been given less consideration comparatively during the last few years. This paper proposes a measurement method for improving service quality of smart phone application. This method combines the service quality performance model (SQPM) and process capability index (PCI). The service quality performance model is used to identify service items that require improvement. Process capability index is used as a measure for prioritization of those improvements. Case study was carried out to search out important communication application service attributes. customer satisfaction level data was collected for users who used the application service. A total of twenty four service attributes were found during this survey. Using the joint approach of SQPM and PCI, five significant service attributes were prioritized for service quality improvement.

Smart phones have drastically changed the life of today’s competitive world. Smart phone application (App) developers are trying their best to meet the customer requirements in the most efficient way while considering all its attributes. However smart phone service quality has been given less consideration comparatively during the last few years. This paper proposes a measurement method for improving service quality of smart phone application. This method combines the service quality performance model and process capability index. The service quality performance model is used to identify service items that require improvement. Process capability index is used to prioritize these items for improvement. We collected data on satisfaction level of customers who have used application service. By the proposed method, we found five significant service items from three categories - execution, security and resilience and prioritized those items for improvement.