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The final goal of this study is to secure production efficiency and quality stability by applying simple automation to the dental implant packaging process, and based on this, it is possible to switch to full automation in the future. Design and build a simple automation system centering on core processes with high repeatability and manual weight during the packaging process, and secure empirical data to verify the effectiveness of applying automation. Through this, the key is to realize effects such as improvement of process speed, minimization of manpower input, and cost reduction, and to establish a technical and operational foundation to enable full automation construction by expanding the modularized automation system in the long run. In other words, this study aims to realize a step-by-step automation strategy through the application of realistic simple automation technology and to design a structural system that can be linked to full automation.

Based on the data obtained by converting the existing analog measurement method's gas regulator inspection process to a digital automatic inspection system, this task is to develop a new high-precision gas regulator that minimizes the false verification rate and maximizes safety. Through this, we intend to secure additional export competitiveness and realize entry into the high value-added market.

The pipes are connected by welding the ends so that they face each other, or, to enhance the assembly, a disc-shaped flange is welded to the end of each pipe, and then the flanges are brought into contact with each other and connected so that they can be separated using bolts and nuts. The ends of pipes with an inner diameter of ∅20 to 50 are plastically processed into a flange shape. This allows for the forming of a flange integral with the pipe, and ensures versatility. When forming a flange on a pipe, it can reduce wear due to friction, improve product quality, and increase the life of the device.

In high-precision manufacturing industries, the use of 5-axis machining centers has been steadily increasing. However, there is a lack of experimental evidence regarding variations in surface roughness depending on the machining path. This study aims to experimentally investigate and analyze how surface roughness is affected by table tilting angles and machining directions in 5-axis machining.

The 30mm wheel type anti-aircraft gun replaces the aging anti-aircraft gun in the front and is a weapon system for local anti-aircraft defense against enemy aircraft and small unmanned vehicles. In the field, damage to the turret hatch/closed hatch pin occurred between the operation of the wheel type anti-aircraft gun. As a result of the sem analysis of the hatch pin fracture surface, it appears that brittleness fracture occurred and fatigue fracture occurred at the final fracture surface while reaching the fatigue strength by repetitive loads. The hatch angle fixing pin and bracket shapes were changed to disperse the stress concentration. As a result of checking the location of the vulnerable area of the hatch pin and the shear stress value through structural analysis, the safety factor improved from 1.46 to 2.95 after improvement. Through this study, it is expected to be used as a reference material for failure analysis and design plan for the existing system in the future.

This study analyzed security weaknesses in triple-factor authentication for IoT-based healthcare systems and proposed improvements. Examining registration, authentication, and session key setup, we found four main vulnerabilities: offline password guessing, user impersonation, session key exposure, and secret key leakage. Recommendations include multi-factor authentication, visual synchronization improvements, side-channel attack prevention, MAC application, and lightweight cryptography. This research provides a basis for secure medical data protection and reliable IoT healthcare environments.

This study analyzed vulnerabilities in a four-factor authentication protocol for IoMT, which uses password, smart card, biometrics, and PUFs. Key weaknesses include biometric protection, key management, session hijacking, and resource constraints. Proposed solutions involve homomorphic encryption, blockchain key management, lightweight and quantum-resistant cryptography, and AI-based adaptive security. This research provides a foundation for improving IoMT security protocol reliability in digital healthcare.

Traditional fingerprint recognition, relying on large datasets and machine learning, often faces accuracy issues due to data heterogeneity and privacy concerns. This study proposes AI-Fed-FR, a novel fingerprint recognition algorithm using explainable AI-based federated learning to enhance accuracy while ensuring privacy. AI-Fed-FR improves global model performance by iteratively aggregating parameters from user devices and employs explainable AI for denoising low-resolution fingerprint images. A storage sampling-based client scheduling technique addresses client imbalance. Experiments on three real-world datasets show AI-Fed-FR achieving 5.32% higher accuracy than local learning and 8.56% higher than average-based federated learning.

Recently many products with gorgeous 3D patterns on the surface have been released as a kitchenware trend, and in particular, research is actively being conducted to implement 3D patterns and designs. Among them, 3D pattern ceramic technology using magnetic ceramic materials has the advantage of easily implementing 3D patterns using neodymium magnets and electromagnet jigs. However, there is a problem that there is a limit to the accurate shape implementation because the strength of the magnetic field varies depending on the size, shape, and arrangement of the magnets mounted on the jig. In this study, we conducted a study on the change in the magnetic field generated according to the gap distance between the jig and the frying pan. As a result, it can be seen that the closer the gap distance, the greater the strength of the magnetic field formed on the frying pan. When the gap distance is 0mm, a magnetic field strength of 15320G is formed, and when it is 4mm, it is half, 7660G, and when it is 10mm or more, it is formed close to 0G. Therefore, it was found that when the gap distance was 10mm or more, no magnetic field was formed inside the frying pan, and it was expected that the magnetic particles would form a 3D shape inside the frying pan at around 0 to 4mm.

In the MR fluid Jet polishing process, the viscosity characteristics of the jetted MR fluid depend on the strength of the magnetic field, which is one of the important factors. Also, the yield stress of the MR fluid increases depending on the strength of the magnetic field, which affects the material removal rate and surface roughness of the workpiece. Therefore, a study was conducted to manufacture the optimal electromagnet part through electromagnet design and analysis. It was confirmed that the magnetic field strength at the front of the electromagnet was 6624.3G, 8554.6G at the half point of the center of the electromagnet, and 6543G at the middle of the electromagnet, and that the area where the magnetic field was most concentrated in the nozzle discharge area was the half point of the center. It was also confirmed that the magnetic field distribution was concentrated in the high-pressure nozzle at the half point of the center of the electromagnet. Through this, it is expected that the MR fluid will be able to have a sufficient magnetic field effect on the MR fluid while passing through the high-pressure nozzle at a high speed.

This study investigates the fluid dynamic characteristics of a magnetorheological (MR) fluid injection system that integrates water jet and MR polishing technologies. The system functions by applying a magnetic field to MR fluid sprayed at high velocity from a nozzle, enabling precision surface finishing. Process variable parameters including injection pressure, velocity, and flow rate significantly influence the polishing performance. It was found that even with a strong and dense magnetic field, unstable injection leads to unpredictable process. Therefore, a fluid dynamic analysis was performed to determine the relationship between the injection variables and the pressure conditions occurring during injection. Based on this analysis, a hydraulic system capable of maintaining stable MR fluid injection was designed and evaluated. The findings of this study contribute to improving the reliability and efficiency of MR-based polishing processes through enhanced control of fluid dynamics.

This study evaluated the industrial applicability of a non-destructive measurement method based on impression materials for complex internal geometries. Using Hydrophilic Vinyl Polysiloxane impression material and a Mitutoyo optical projector, repeated measurements (total 60 data points) were taken on dovetail groove samples. A Gage R&R analysis showed %EV at 12.75%, %AV at 5.5%, and %GRR at 13.9%, indicating conditionally acceptable reliability according to AIAG criteria. The results confirm the method's practical potential for industrial use, with opportunities for repeatability improvement. Future integration with digital imaging and AI edge-detection technologies is expected to further enhance automated precision measurement capabilities.

In this study, structural durability enhancement of the fuel tank support bracket for a KMTV was investigated. During the component-level durability test, a fracture was observed at approximately 250,000 cycles under a target of 570,000 cycles, indicating the need for structural reinforcement. To address this issue, a reinforced bracket was designed. Durability analysis was conducted using finite element modeling, with only the bracket geometry changed while maintaining consistent boundary condition. The analysis results showed that the reinforced design achieved a durability life approximately 15 to 16 times longer than the original bracket. These findings demonstrate the effectiveness of the reinforcement design in significantly improving fatigue life under repetitive load condition. Future work includes vehicle-level endurance testing to validate the correlation between simulation results and actual performance, as well as further refinement of the design based on various operational conditions.

The center bearing of the propeller shaft in the KM-Sam mounted vehicle is a component that requires high durability due to high-speed rotation and it must exhibit strong resistance to vibration and strees. However some Republic of Korea Air Force (ROKAF) units have experienced failures where the center bearing bracket breaks, leading th the detachment of the propeller shaft assembly. This issue has only occurred with domestically developed center bearings, A root cause analysis confirmed excessive second-order components and stress, Therefore improved results were derived through comparative testing with imported parts, and the effectivenss was verified by applying them to actual vehicles.

In modern industrial environments, automation paradigms that replace hazardous human work areas with robots are accelerating alongside technological advancement. The economic efficiency and task performance capabilities of robotic systems have emerged as key factors for successful industrial implementation. Manufacturing and hazardous industries recognize hardware cost reduction and software advancement as essential prerequisites for robot adoption. Quadruped robots have gained attention in industrial environments due to their exceptional mobility in irregular terrain and complex environments. This study implements rapid and safe mission execution through LiDAR sensor-based real-time obstacle avoidance and gesture recognition systems. Furthermore, we develop systems that perform specific tasks according to operators' intuitive commands by introducing gesture recognition as a human-robot interaction interface. This research designs and implements quadruped robots that integrate obstacle avoidance and gesture-based task command processing modules while recognizing static and dynamic environmental objects in real-time through LiDAR sensors. We aim to significantly enhance robot utilization in industrial sites and present practical robotic solutions capable of replacing humans in hazardous work environments.

We propose a method for recognizing gestures from a specific user in multi-user environments. Previous studies require expensive equipment or demand users to become familiar with specialized devices, which poses practical limitations. We utilize OpenCv to detect a specific marker and employs MediaPipe’s real-time hand tracking to recognize only the hand with the detected marker. This method reduces malfunction rates. In multi-user experiments, the system reduced misrecognition of unintended user’s gestures by more than 90%, enabling highly reliable and user-specific gesture recognition. In simultaneous tests with hands both with without the marker, only the hand bearing the marker was accurately recognized, confirming the effectiveness of the proposed system.

This study aims to evaluate the magnetic adhesion performance of an automatic grinding device used in shipyards, where surface finishing remains largely manual despite its importance to weld quality and painting preparation. To improve operational stability and reduce dependence on manual labor, a finite element analysis (FEA) was conducted to examine the effects of magnet quantity and air gap distance between the magnets and ferromagnetic surfaces. Three design cases were analyzed with two, four, and six magnets, respectively, and the air gap was varied from 5 mm to 10 mm. The magnetic flux density and resulting attractive force were calculated based on Maxwell stress equations. Results showed that increasing the number of magnets improved the adhesion force, with Case III (six magnets) yielding the highest force of 329.12 N at a 5 mm gap. The required adhesion force was also theoretically derived using a free body diagram and energy-based approach, confirming that Case III meets the necessary force (308 N) for stable vertical surface operation. These findings suggest that optimal magnet configuration is critical for ensuring safe and consistent performance of automatic grinding systems in harsh shipyard environments.

In recent years, fibre reinforced composites have attracted much attention for their properties such as low density, high specific strength, high modulus, flame retardancy, heat resistance, stable chemical properties, radiation resistance, and durability. In this study, the mechanical performance and fatigue life of fiber-reinforced composites were measured. As a result, CFRP and AFRP manufactured with 8-laminated layers had fatigue strengths of more than 107 cycles at 455 MPa and 200 MPa, respectively. CFRP composites exhibited the highest tensile strength.

This study is to develop a multi-stage variable section high-speed cutting device for recycling waste storage tanks. The cutting device is developed with a new cutting method that can cut various waste storage tank carbon fibers into scrap form within a short period of time by using a multi-stage variable section high-speed cutting function and a diamond wire tool. This development of cutting items include the development of diamond wire tools and wheels, development of cutting transfer systems, structural frames, cooling system applications, and hydrogen tank fixing systems, among other parts, which can provide new processing data such as technical development and design.

본 연구에서는 A*, RRT, D* Lite 세 가지 대표적인 경로 계획 알고리즘의 출력을 환경 특성에 따라 가중치를 부여하여 융합하는 적응형 가중치 투표 융합(Adaptive Weighted Voting Fusion) 기법을 제안한다. 실험 환경은 100×100 격자로 구성되며, 중앙 통로를 포함한 구조화된 장애물 배치를 통해 장애물 밀도를 기준으로 개방형(Open, 0.05), 혼합형(Mixed, 0.2), 혼잡형(Cluttered, 0.4)으로 분류된다. 각 알고리즘의 경로는 알고리즘 특성을 반영한 가우시안 노이즈를 통해 다양화되며, 중간 웨이포인트는 DBSCAN 클러스터링을 통해 통합된다. 이후 환경별 적응형 가중치를 적용한 가중 평균 방식으로 클러스터 중심점을 계산하고, 이를 기반으로 경로 정렬, 단순화, 평활화, 안전성 검증을 통해 최종 융합 경로를 생성한다. 실험 결과, 제안된 융합 경로는 모든 환경에서 A* 알고리즘 대비 더 짧고 단순화된 경로를 생성하였으며, 특히 장애물 밀도가 높은 환경에서 더욱 뛰어난 성능을 보였다. 경로 길이는 A* 알고리즘 대비 평균 11.6~16.0% 단축되었으며, 개방형 환경에서는 단 3개의 웨이포인트로 구성된 최적의 경로를 도출하였다. 제안된 기법은 환경 적응성과 견고성이 높아, 실내 자율주행이나 재난 구조 로봇 등 실제 응용 분야에서 효과적으로 활용될 수 있다.

In this study, response spectrum analysis reflecting fluid-structure interaction (FSI) was performed to conduct seismic analysis of the steel containment vessel of a small modular reactor (SMR) submerged in a water tank. A three-dimensional finite element model combining structural and acoustic elements was constructed, and the natural frequencies and mode shapes including FSI were derived through eigenvalue analysis for the asymmetric mass and stiffness matrix. The response spectrum analysis was performed by applying the design response spectrum with 5% damping, and the results were compared with the in-air model. Under underwater conditions, the natural frequencies are lowered due to the fluid-added mass effect, and the structural response seems to be amplified in the range of 5–20 Hz. The proposed procedure can be effectively utilized in the seismic design and regulatory review of underwater SMR containment vessels.

In this research, the design and fabricated method of endless diamond wire cutting tool that can secure continuity and efficiency in cutting process of waste hydrogen storage tank carbon fibers. To complement the shortcomings of the existing open-loop structure and to improve wear uniformity and process stability, an endless loop-shaped wire tool was developed. The fabricated wire maximized the cutting performance by uniformly distributing and fixing diamond particles on a high-strength steel core. In this research, the applicability and advantages of the wire tool are presented through a comprehensive approach including design concept, material selection, manufacturing process, and ANSYS structural analysis.