• Journal of the Microelectronics and Packaging Society
• /
• v.28 no.4
• /
• pp.51-55
• /
• 2021

The nurses manually carry out the intravenous therapy for the patients. Using an Arduino, the fine flow controlling device was invented to provide an ongoing patient care. The medication is injected through a peristaltic pump, and the amount of the solution is controlled with a RGB color sensor. The power of the device is supplied through the batteries. An amount of the injection is measured with LIG strain sensor fabricated by 355nm UV pulsed laser. This system will provide a better medical service.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.3
• /
• pp.49-55
• /
• 2022

The design of a battery package and a BMS module for applications using seawater rechargeable batteries, which are known as next-generation energy storage devices, is proposed herein. Seawater rechargeable batteries, which are currently in the initial stage of research, comprise primarily components such as anode and cathode materials. Their application is challenging owing to their low charge capacity and limited charge/discharge voltage and current. Therefore, we design a method for packaging multiple cells and a BMS module for the safe charging and discharging of seawater rechargeable batteries. In addition, a prototype seawater rechargeable battery package and BMS module are manufactured, and their performances are verified by evaluating the prevention of overcharge, overdischarge, overcurrent, and short circuit during charging and discharging.

• Journal of the Microelectronics and Packaging Society
• /
• v.28 no.4
• /
• pp.19-23
• /
• 2021

A statistical approach to inspection of the 3-D shape of micro solder balls is proposed, where an optical method with spatially arranged LED and specular reflection is used. The reflected image captured by a vision system was analyzed to calculate the relative displacements of LED's in the image. Also, the statistics of displacements for the solder balls contained in a captured image are used to detect existing defects, and the usefulness of the proposed method is shown via experiments.

• Journal of muscle and joint health
• /
• v.30 no.3
• /
• pp.263-272
• /
• 2023

Purpose: The aim of this study was to provide a scientific basis for shelf life and re-establish the shelf life in a hospital environment by investigating the validity periods of various packaging materials. Methods: We selected six departments to store sterilized items, prepared 482 sterilized items, and stored them for 12 months. Each sample was tested using a microbiological culture in the laboratory every two weeks. When the result was positive, the sample was considered contaminated. The temperature and relative humidity were measured using an automatic control system to investigate the storage environment during the study period. Results: Except for two samples, which were positive in the 22nd and 28th weeks, 480 samples were negative. The temperature and relative humidity of the sample storage area were measured every week. The annual average temperature was 23.6±1.6℃, and the mean relative humidity was 35.1±15.2%. The cabinets used in this study were the two-open and four-closed types. Conclusion: This study confirmed the validity of the expiration date in a hospital environment. Based on the results, the nonwoven fabric remained sterile for more than nine months. No case of contamination of the paper-plastic pouch packaging was observed, owing to the microbial culture for two months.

• Journal of the Microelectronics and Packaging Society
• /
• v.31 no.2
• /
• pp.45-53
• /
• 2024

The maintenance of semiconductor equipment is crucial for the continuous growth of the semiconductor market. System management is imperative given the anticipated increase in the capacity and complexity of industrial equipment. Ensuring optimal operation of manufacturing processes is essential to maintaining a steady supply of numerous parts. Particularly, monitoring the status of substrate transfer robots, which play a central role in these processes, is crucial. Diagnosing failures of their major components is vital for preventive maintenance. Fault diagnosis methods can be broadly categorized into physics-based and data-driven approaches. This study focuses on data-driven fault diagnosis methods due to the limitations of physics-based approaches. We propose a methodology for data acquisition and preprocessing for robot fault diagnosis. Data is gathered from vibration sensors, and the data preprocessing method is applied to the vibration signals. Subsequently, the dataset is trained using Gradient Tree-based XGBoost machine learning classification algorithms. The effectiveness of the proposed model is validated through performance evaluation metrics, including accuracy, F1 score, and confusion matrix. The XGBoost classifiers achieve an accuracy of approximately 92.76% and an equivalent F1 score. ROC curves indicate exceptional performance in class discrimination, with 100% discrimination for the normal class and 98% discrimination for abnormal classes.

• Journal of the Microelectronics and Packaging Society
• /
• v.31 no.3
• /
• pp.62-66
• /
• 2024

A statistical approach to inspection of the 3-D shape of micro solder balls is proposed, where an optical method with spatially arranged LED and specular reflection is used. The reflected image captured by a vision system was analyzed to calculate the relative displacements of LED's in the image. Also, the statistics of displacements for the micro solder balls contained in a captured image are used to detect existing defects, and the usefulness of the proposed method is shown via experiments.

• Food Science and Preservation
• /
• v.9 no.3
• /
• pp.271-276
• /
• 2002

To develop a wrapping film, which suppresses the microbial decay through the storage and prolongs the selflife of fruits and vegetables, the antimicrobial packaging films were prepared and applied to the preservation of strtwberries and cucumbers. Low density polyethylene(LDPE) film of 50㎛ thickness was faricated with 1% of Scutellariae baicalensis extract. The LDPE film impregnated with Scutellariae baicalensis extract showed antimicrobial activity on the disk test against Bacillus cereus, Escherchia coli and Fusarium sp.. The antimicrobial film changed the color and light transmittance, but did not affect heat shrinkage, mechanical tensile strength and wattability. Strawberries and cucumbers were separately wrapped with packaging films in the state of closely-adhered packaging as well as modified atmosphere packaging(MAP). The wrapped strawberries and cucumbers were stored for 21 days at 5$\^{C}$ and for 40 days at l0$\^{C}$, respectively. For the packaged strawberries and cucumbers at 5$\^{C}$ and 10$\^{C}$, the LDPE film impregnated with Scutellariae baicalensis extract showed the reduced growth of total aerobic bacteria, molds and yeasts and did not give any negative effect on other quality attributes during storage in comparison with conttrol film without any additive.

• Transactions on Control, Automation and Systems Engineering
• /
• v.2 no.1
• /
• pp.1-6
• /
• 2000

This paper presents a control of active suspension for quarter car model with two degree of freedom by using H$\infty$ method. Absolute velocity of car body is measured for feedback. The system parameter variations are treated with multiplicative uncertainty model. Simulation results show that the H$\infty$ control provides good trade-off between ride quality, suspension packaging and road holding constraints. The experiment with a front wheel suspension system was done to verify the simulation results.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.2
• /
• pp.43-53
• /
• 1998

This paper addresses an optimization for reducing a steering error of a rack-and-pinion steering linkage with a MacPherson strut independent front suspension system. The length, orientations and inner joint positions of a tie-rod are selected as design variables and Ackerman geonetry, understeer effect, minimum turn radius, wheel alignment and packaging are considered as design constraints. Nonlinear kinematic analysis of the steering system is performed for calculating the values of cost and constraints, and Augmented Lagrange Multiplier(ALM) method is used for solving the constrained optinization problem. The optimization results show that the steering error are considerably reduced while satisfying all the constraints.

• Journal of Korea Multimedia Society
• /
• v.25 no.8
• /
• pp.1085-1096
• /
• 2022

The manufacturing industry is continuously pursuing advanced technology and smartization as it converges with innovative technology. Improvement of manufacturing productivity is achieved by monitoring, analyzing, and controlling the facilities and processes of the manufacturing site in real time through a network. In this paper, we proposed a new OPC-UA based digital twin model for smart factory facilities. A testbed system for USB flash drive packaging facility was implemented based on the proposed digital twin model and OPC-UA data communication scheme. Through OPC-UA based digital twin model, equipment and process status information is transmitted and received from PLC to monitoring and control 3D digital models and physical models in real time. The usefulness of the developed digital twin testbed system was evaluated through usability test.