# Smart Trash Bin Model Design and Future for Smart City
## 4 Comparison with Other Cases and Performance Evaluation  
Dr. Boomerang and CleanCube are the experimental products for the Korean domestic market developed by Ecosave and E-cube Lab, respectively. The following are their descriptions [35; 36]. Dr. Boomerang by Ecosave in Figure 7 has a bar code reader that scans the bar codes printed on the cans or plastic products disposed of through the separate exclusive slots. The weight of each disposed item is calculated and converted to mileage, which will be returned to the user to be used as usable points for his/her transportation or cash-back cards. This unit had been used by the Seoul Metropolitan Government and test-operated at the Pedestrian-Friendly Street in front of Hongik University in the ROK. Figure 8 shows Dr. Boomerang currently on sale at Ecosave. Compared to previous products, miniaturization has been carried out, information that can be displayed through the display has diversified, and various functions have been added, such as advertising through receip  
Figure 7: Prototype Dr. Boomerang by Ecosave. The disadvantage of this product is that it does not distinguish between other materials without bar codes. Also, it is not feasible to store all the bar codes that will be able to distinguish between materials in its internal database (DB), and the accuracy cannot be guaranteed. Meanwhile, CleanCube by E-cube Lab, in Figure 9, compresses the collected waste so that it can store more volume. The other advantages are that the unit does not require any separate wiring, as it utilizes solar power and, installed with monitoring software, it can check the current load, the remaining battery power, and the mechanical errors in real-time. However, while the unit's compression function may be helpful in reducing the manpower and costs, it lacks efficiency as the collected waste must be sorted out again following the recycling rules because all sorts of waste are compressed without any distinctions. The notable products in the global market are Pugedon. Pugedon [37] discharges a certain amount of animal feed at the bottom when the user puts the plastic trash into the slot. This machine is powered by solar energy. Its disadvantage is that only plastic is recyclable so it does not completely serve the purpose of recycling. For the Trash Bin by Incom Recycle, Figure 10 shows the cash-back system [38] that compensates for the disposed recyclables, currently being used in Beijing and Shanghai. This service offers cash-back when one puts recyclables into the system. Figure 8: Dr. Boomerang by Ecosave. Figure 9: An experimental product by E-cube Lab. Founded in 2003, INCOM is one of China's second circular economy pilot units and standing directors of the China Packaging Federation. With China's special approval in 2006, INCOM established a polyester production line for food-grade recycled bottles. It can handle 50,000 tons, which is 2.2 billion trash PET bottles per year, and can produce 30,000 tons of recyclable PET pieces and 20,000 tons of recyclable clean polyester chips. In this way, INCOM was able to adequately fill the gap in China's recycled polyester chip market. In 2012, it successfully developed China's first intelligent recycling machine for the IoT, and an intelligent management platform for recycling resources and flow control [38]. Table 5 shows a comparison of each of the models. The proposed model is designed to be specialized for the trash classification task. Therefore, spectroscopy and image classification techniques were used to classify various types of trash. Even though the proposed system was primarily developed for public use and its principal agents are the local governments, it is quite possible to expand the range of use by supplying the system to the general population for individual use at home. A little modification in design and a change in the price level will be required for this purpose.