• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.365-368
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• 2021

In this study, a plastic bottle recycling bin system that utilizes an infrared sensor was implemented. The proposed system consists of a recognition unit, a control unit, an alarm unit, and a driving unit. The recognition unit detects the plastic bottle, measures the distance between the plastic bottle and the infrared sensor, extracts the value of the bottle, compares the extracted value with a standard range, and then transmits the control value to the control unit if the extracted value of the bottle is outside the standard range. In this case, the result of the presence or absence of a brand label or bottle cap is transmitted to the controller. The control unit opens the entrance of the recycling bin or alerts the alarm unit according to the result value transmitted from the sensor unit. In order to implement the proposed system, the recognition unit was implemented with an infrared sensor, and the control unit was made with an Arduino IDE controller, based on the C programming language. Additionally, the recognition unit and the control unit are able to communicate using analog signals. The proposed system accurately judges the presence or absence of a brand label and bottle cap of plastic bottles according to a predetermined algorithm. It then blocks the entrance of the recycling bin when a brand label or bottle cap is still attached. As the amount of waste discharged per person is relatively high and the majority of such waste is incinerated rather than recycled, the system proposed in this study is expected to increase the recycling rate of plastic bottles.

• Design & Manufacturing
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• v.17 no.4
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• pp.33-41
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• 2023

Excessive use of plastic bottles contributes to a significant environmental issue due to the high volume of plastic waste generated. To address this, efforts are needed to reduce the weight of plastic bottles. However, indiscriminate weight reduction may compromise the essential rigidity required for plastic bottles. Extensive research on rib shape for pressure vessels are exists, but there is a few research of rib shapes to enhance the stiffness of plastic bottles. The following results were obtained from the analyses conducted in this study. 1) Among the rib cross-sections of square, trapezoid, and triangle, the buckling critical load of PET bottles with square-shaped ribs is improved by about 14% compared to the buckling critical load of PET bottles without ribs. 2) The buckling critical load is improved by about 18% when a square-shaped rib with an aspect ratio of 0.2 is applied, compared to the buckling critical load of the bottle without the rib. 3) When longitudinal and transverse square ribs were applied to the axial direction of the PET bottle, the buckling critical load was improved by about 32% and 58% compared to the buckling critical load of the PET bottle without ribs, respectively, indicating that applying longitudinal ribs is effective in reinforcing the stiffness of PET bottles. 4) When 14 transverse ribs were applied, the maximum improvement was about 48% compared to the buckling critical load of the plastic bottle without ribs. 5) When 3 longitudinal ribs were applied on each side, the maximum improvement was about 76% compared to the buckling critical load of the bottle without ribs. Therefore, it was concluded that for effective stiffness reinforcement of a 500ml square bottle with a thickness of 0.5mm, 3 square-shaped ribs with an aspect ratio of 0.2 should be applied in the longitudinal direction relative to the axial direction of the bottle.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.813-818
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• 2009

Shear properties of plastic bottle film/plastic bottle film and plastic bottle film/granitic soil which were evaluated from static friction tests. The monotonic shear experiments were performed by using an tilt table apparatus and large direct shear device. The test results showed that the friction angle of each interface and the interface depended on the amount of normal stress, the type of the interface used. Therefore, the testing method should be determined carefully by considering the type of loads and normal stress expected in the field with using the materials installed in the site.

• Resources Recycling
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• v.17 no.1
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• pp.43-50
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• 2008

In this study, we carried out the research on triboelectrostatic separation for materials separation of PET & Nylon recovered to waste plastic beer bottle. From the research on charging characteristic for choice of charging materials, it was found that PMMA was optimum charging material to make high charging amount with opposite polarity for PET & Nylon in waste plastic beer bottle. Therefore, we manufactured a charger of pipe line and cyclone type using PMMA material for separation of PET and Nylon. At optimum test conditions that used PMMA pipe line and cyclone charger developed in this study, we developed a triboelectrostatic separation technique that can separate PET plastic up to grade of 99.6% and recovery of 88.2%. We established new separation technology that can recycle the PET and Nylon recovered from waste plastic beer bottle.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.31-42
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• 2024

This review paper provides a detailed analysis of PET (polyethylene terephthalate) bottle recycling in Japan. Japan is a global leader in PET bottle recycling due to its advanced regulatory framework and proactive industry initiatives. Japan's success attributes to the widespread adoption of bottle-to-bottle recycling, driven by the beverage industry's commitment to sustainability. By utilizing post-consumer PET bottle recovery and food-grade mechanical recycling technologies, Japan has achieved significant milestones in PET bottle recycling. This paper examines regulatory frameworks, collection systems, reprocessing facilities, and food safety assessments to highlight Japan's innovative approaches to PET bottle recycling and their impact on global sustainability efforts. Drawing parallels with Korea's early stages of PET recycling, it suggests involving major beverage companies and re-evaluating regulations to promote bottle-to-bottle recycling. The focus is on the implications for Korea to promote circular economy principles in plastic recycling.

• Elastomers and Composites
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• v.57 no.4
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• pp.205-214
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• 2022

Research on reducing the thickness of polyethylene terephthalate (PET) bottles is necessary to reduce the amount of plastic used. However, as decreasing a PET bottle's thickness weakens it, a robust bottle design is required. Therefore, in this study, we numerically analyzed various bottom designs of a carbonated soft drink PET bottle with 245 and 500 ml capacities and complicated petaloid shapes. Deformation, equivalent stress, maximum principal stress, and its direction according to each design were analyzed to study the strength of the bottle. The results serve as a reference to design robust petaloid PET bottle bottoms with a reduced thickness for carbonated soft drinks.

• Elastomers and Composites
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• v.54 no.2
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• pp.123-127
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• 2019

Shrink film is currently being used for plastic container lavels to avoid the use of glue. Polyethylene terephthalate (PET) bottle lavels also use shrink films in the same PET materials for easy recycling of PET bottles. An air layer is generated between the shrink film and PET bottle surface due to the bent shape of the bottle surface. This air layer can insulate external heat, as air has a relatively lower thermal conductivity. In this study, the insulation property of the air layer was examined by computer simulation. Two PET bottle models were used, one with and the other without an air layer between the PET bottle surface and lavel. The two bottle models were filled with cold liquid and exposed to room temperature for 6 h, and the temperatures of the contents were then compared. The results showed that the temperature of the contents in the bottle with the air layer was lower than that without the air layer by at least $2^{\circ}C$. This study suggests an effective lavel design of PET bottles while ensuring that the temperature of the bottle contents is maintained.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.385-392
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• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.4
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• pp.484-496
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• 1996

This paper presents an anlaysis on the thermodynamic performance of ice storage system. The primary interest in this work is the exergetic efficiency of the system. The ice storage system considered here is the capsule type system with the waste plastic bottle being used as a capsule. To examine the characteristics of irreversibility production and exergetic efficiency in detail the ice storage system to be analyzed has been separated from the refrigerator in this analysis. The analysis is based on the lumped model with 3 uniform temperatures. The results indicate that 3 dimensionless parameters can describe the exergetic efficiency of the system, from which the characteristics of irreversibilities and the ranges of these parameters to ensure the reasonable performance of the system can be found. Experiments also have been performed to demonstrate the feasibility of such a system. This analysis only shows the performance of ice storage side, with the refrigeration side excluded. However, the results can be interpreted as a total performance if the refrigerator coupled with the ice storage system operatres reversibly.

• The Journal of Korea Robotics Society
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• v.14 no.2
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• pp.81-86
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• 2019

Robots are used in various industrial sites, but traditional methods of operating a robot are limited at some kind of tasks. In order for a robot to accomplish a task, it is needed to find and solve accurate formula between a robot and environment and that is complicated work. Accordingly, reinforcement learning of robots is actively studied to overcome this difficulties. This study describes the process and results of learning and solving which applied reinforcement learning. The mission that the robot is going to learn is bottle flipping. Bottle flipping is an activity that involves throwing a plastic bottle in an attempt to land it upright on its bottom. Complexity of movement of liquid in the bottle when it thrown in the air, makes this task difficult to solve in traditional ways. Reinforcement learning process makes it easier. After 3-DOF robotic arm being instructed how to throwing the bottle, the robot find the better motion that make successful with the task. Two reward functions are designed and compared the result of learning. Finite difference method is used to obtain policy gradient. This paper focuses on the process of designing an efficient reward function to improve bottle flipping motion.