Many manufacturers applying third party logistics (3PLs) have some challenges to increase their logistics efficiency. This study introduces an effort to estimate the weight of the delivery trucks provided by 3PL providers, which allows the manufacturer to package and load products in trailers in advance to reduce delivery time. The accuracy of the weigh estimation is more important due to the total weight regulation. This study uses not only the data from the company but also many general prediction variables such as weather, oil prices and population of destinations. In addition, operational statistics variables are developed to indicate the availabilities of the trucks in a specific weight category for each 3PL provider. The prediction model using XGBoost regressor and permutation feature importance method provides highly acceptable performance with MAPE of 2.785% and shows the effectiveness of the developed operational statistics variables.

PURPOSES : In this study, an eco-friendly mastic asphalt backfill material is developed to reduce production and construction temperatures by 40 ℃ compared with those recorded when using conventional hot-mix mastic asphalt backfill materials. METHODS : To reduce the production and construction temperatures, SIS polymer modifiers and gum rosin were selected, and gum rosin-modified SIS materials were applied to the mastic asphalt binder mix design. SIS is less viscous than SBS at high temperatures owing to its thermal characteristics, and incorporating gum rosin into SIS causes the latter to exhibit a loose and soft structure. To improve the performance of the mastic asphalt modified with SIS and gum rosin, three different filler mixes, i.e., 100% PMMA, 50% PMMA and 50% calcium carbonate, and 40% PMMA and 60% calcium carbonate were applied. RESULTS : The rosin-modified SIS reduces the viscosity of the developed mastic asphalt binders. In particular, incorporating 3.7% of gum rosin is beneficial to the mastic binder and does not degrade its low-temperature performance. Similarly, using 100% PMMA as a filler improves the performance but results in workability issues at high temperatures. CONCLUSIONS : Rosin-modified SIS and PMMA are promising alternatives for increasing the workability at high temperatures while maintaining the target performance of grade PG82-22 binders if the appropriate ratio of calcium carbonate is mixed with PMMA and an alternative filler comprising calcium carbonate is used.

Recently, the construction of tall buildings utilized by high strength-concrete in the whole world is tending to be on the rise. The application of high-rise structural system in buildings results in the excellent cut-down effect in construction materials due to section reduction. Therefore, in order to investigate the CO2 and resource reduction effect for the high-rise structural system, comparisons of GWP and ADP in embodied energy of structural materlais between 4 type of high-rise structural system have been performed. As a result, GWP emission increased in the order of steel structure outrigger system, RC shear wall system, and RC outrigger system. On the other hand, ADP emissions increased in the order of RC shear wall system, RC outrigger system, and steel structure outrigger system.

본 연구의 목적은 디지털 트랜스포메이션의 도입이 가속화 된 경영 환경 속에서 조직 내 인적자원개발(human resource development: HRD) 담당자들이 경험하는 업무 변화에 대해 알아보고, 그에 따른 필요역량 및 업무 수행 시 겪는 어려움을 탐색하는데 있다. 이러한 목적을 달성하기 위해 HRD 업무를 담당하는 현직 종사자 10명을 대상으로 하여 일대일 심층 인터뷰를 실시하였다. 그 결과 디지털 트랜스포메이션시대에 HRD 담당자의 업무는 NCS 기반의 능력단위를 기준으로 하여 전통적인 업무와 비교했을 때 강화, 감소 또는 새롭게 추가된 업무가 있는 것으로 나타났다. 또한 필요 역량은 지식, 기술, 태도, 능력이라는 범주로 나누어 도출하였는데, 테크놀로지 활용 기술 및 변화에 적극적이고 긍정적으로 대응하려는 태도 및 능력이 중요한 것으로 나타났다. 전체적으로 디지털 트렌드 및 스킬에 대한 지속적인 학습으로 인해 업무량은 증가한 것으로 나타났다. 이상의 결과를 바탕으로 본 연구에서는 조직원들의 변화를 이끌어가야 하는 HRD 담당자들에게 실천적 시사점을 제시하고, 연구의 제한점 및 향후 연구 방향에 대하여 제언하였다.