간행물

한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌

권호리스트/논문검색
이 간행물 논문 검색

권호

제26권 제6호 (2024년 12월) 46

1.
2024.12 구독 인증기관 무료, 개인회원 유료
This study presents the development of an algorithm that detects potential front bumper collisions caused by road inclinations and provides early warnings to drivers. The system uses a Time-of-Flight (ToF) infrared distance sensor and an obstacle detection sensor, both implemented on an Arduino-based platform. By continuously monitoring the road ahead, the algorithm measures and analyzes the slope angle to identify potential hazards. This solution offers a cost-effective and efficient alternative to traditional warning systems, notifying drivers in advance of dangerous road conditions and helping to prevent vehicle damage caused by sudden changes in road gradient.
4,000원
2.
2024.12 구독 인증기관 무료, 개인회원 유료
This study examines career trajectories among women with career breaks, using data from the 2019 National Survey of Women on Career Breaks (n=1,138). The data underwent preprocessing, including outlier detection, feature scaling, and class imbalance correction with SMOTEENN. Three machine learning models were evaluated, with the Random Forest model achieving the best performance. Key predictors included flexible leave policies, social insurance, remote work options, and job security. The findings highlight the importance of supportive organizational policies in retaining female employees. Future research should explore longitudinal impacts and additional variables like organizational culture.
4,000원
3.
2024.12 구독 인증기관 무료, 개인회원 유료
In order support the design support system of small and medium-sized shipbuilding companies that carry out designs using 2D CAD, this study developed a system that automatically calculates the cable length by extracting the Y-axis value expressed as text data in 2D CAD. By setting the equipment where the cable starts and ends, the essential route and the installation rate were checked so that the optimal route of the cable could be calculated. As a result, the value calculated based on the optimal route and length of the cable by extracting the data of 2D CAD through this study was the same as the value previously calculated by the actual user, and the installation rate was less than 130% so there was no problem with the on-site installation. In addition, it was confirmed that the cable length calculated through this was reduced by about 7% compared to the existing work.
4,000원
4.
2024.12 구독 인증기관 무료, 개인회원 유료
This study analyzed actual traffic accident data to select humans’ unavoidable accidents and to examine whether avoidance is possible after AEBS(Advanced Emergency Braking System) is applied to these accidents. In cases where avoidance is not possible with AEBS, those accidents were determined to be examples where V2X(Vehicle-to-Everything) technology is necessary. Subsequently, by applying V2V(Vehicle-to-Vehicle) and V2I(Vehicle-to-Infrastructure) communication technologies, this research analyzed the possibility of accident avoidance. The results confirmed that the application of V2X technology enables accident avoidance. Additionally, by applying various variables, it identified limitation scenarios that cannot be resolved by V2X technology, and discussed strategies for accident avoidance in such situations.
4,000원
5.
2024.12 구독 인증기관 무료, 개인회원 유료
The importance of indoor air quality has significantly increased after the COVID-19 pandemic. This study analyzed the energy consumption of a ventilation system based on various operating methods considering indoor and outdoor conditions. From March to May 2024, experiments were conducted on ventilation systems installed in a hospital in Incheon, comparing the experimental and control groups. The results showed that using the bypass mode in the experimental group reduced total energy consumption by 25.34% compared to the control group. Additionally, utilizing the air-cleaner mode further reduced energy use. This study demonstrates that optimal use of bypass and air-cleaner modes can enhance energy efficiency. Further research is needed to verify long-term applicability under diverse conditions.
4,000원
6.
2024.12 구독 인증기관 무료, 개인회원 유료
This study intends to analyze physical and chemical changes using Thermo-Gravimetric Analysis (TGA) of MGO-bioethanol mixed fuel oil. We will analyze the thermal stability and state changes of MGO-Bioethanol mixed fuel oil and conduct and utilize various basic experiments on its applicability as ship fuel oil in the future and eco-friendly alternative fuels. The physical and chemical conditions set through this experiment were set through non-isothermal heating at about 20°C to 933°C, and the heating rate was 100°C/min, the measurement time was 10 minutes, and the amount of samples in each mixed fuel oil was about 18mg-24mg. In the range of pyrolysis temperatures from 235.241°C to 253.320°C, the weight of BE0 was 30.992%, BE10 was 36.199.%, BE20 was 35.879%, and BE30 was 35.725%, indicating that the pyrolysis temperature and weight tended to increase as the bioethanol content increased.
4,000원
7.
2024.12 구독 인증기관 무료, 개인회원 유료
Automotive technology has developed rapidly and is becoming the intensive of cutting edge technology. For this reason, Automotive are used not only as a means of transportation, but also as a private and leisure spaces. The driver wants to keep quiet even if the car is used for a long time. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was presented that a seven-step procedure for failure diagnosis and repair to reduce noise/vibration. NVH was diagnosed by comparing the result of the rotator order tracking analysis with the problem frequency. It was possible to accurately analyze the cause of noise and vibration, also it coud identify the location, and repair that.
4,000원
8.
2024.12 구독 인증기관 무료, 개인회원 유료
In various machines used in industrial sites and transportation equipment, fastening structures of bolts and nuts are widely employed. However, conventional Steel sockets, classified as non-explosion-proof materials, have a high likelihood of generating sparks due to friction with components, which can lead to explosions or large-scale fires. To address this issue, this study developed a lightweight explosion-protection socket using AL-7075-T6 aluminum alloy, which is known for its excellent explosion-proof properties. However, due to the inherent characteristics of aluminum, it has lower rigidity compared to Steel, requiring the use of more expensive alloy materials. Therefore, our research team utilized Finite Element Analysis (FEA) and Multi-Objective Genetic Algorithm (MOGA) to optimize the mass and safety factor of the socket, proposing a design that simultaneously achieves both weight reduction and structural stability. The socket developed in this study is approximately 30% lighter than traditional Steel-based sockets while maintaining a safety factor of 1.2 or higher, significantly enhancing operational safety in explosive environments. This research sets a new standard in the design and manufacturing process of explosion-proof sockets and is expected to contribute to the optimization of various explosion-proof equipment in the future.
4,000원
9.
2024.12 구독 인증기관 무료, 개인회원 유료
The multi-local resonance metamaterial is based on the local resonance mechanism of resonators, effectively blocking wave propagation within multiple resonant frequency ranges, a phenomenon known as band gaps. In practical applications for vibration reduction, the goal is to achieve wide-band vibration attenuation at low frequencies. Therefore, this study aims to improve the vibration reduction performance of multi-local resonance metamaterials by lowering the band gap frequency and expanding the band gap width. To achieve this, an objective function was formulated in the optimization problem, considering both the frequency and width of the band gap, with the geometric shapes of the multiple local resonators selected as design variables. The Sequential Quadratic Programming (SQP) technique was employed for optimization. The results confirmed that the band gap was generated at lower frequencies and that the band gap width was expanded.
4,000원
10.
2024.12 구독 인증기관 무료, 개인회원 유료
The turbine wheel plays a crucial role in operating turbines, and with recent advancements in technology, the performance requirements for turbine wheels have significantly increased. Consequently, it is essential to predict failure speeds, as turbine wheels must maintain high stability and reliability under harsh operating conditions. In this study, only the centrifugal loads generated by rotati were considered, excluding conditions such as temperature and pressure. A round-shaped fuse section was applied to the turbine wheel, and the stresses induced by variations in shape were analyzed to predict failure speeds. The results obtained using the Hallinan criteria were compared with the results from finite element analysis (FEA) to validate the predicted failure speeds, showing good agreement between the two methods.
4,000원
11.
2024.12 구독 인증기관 무료, 개인회원 유료
In 2013, Imsil Pilbong Culture Village installed a dome-shaped membrane structure off a ceiling of an outdoor performance hall in order to support performances under bad climate condition. However, sound energy during the performance is collected under the dome structure and bounced back to the stage, which produces mixed acoustic which causes a serious acoustic defects. So, in this study, in order to improve the acoustical performance of the outdoor performance hall in Korea Soriter, two sound performance improvements were proposed using sound simulation according to the installation suspension absorbers after identifying acoustic defects through field measurement. The results of study, the comparison between sound performance improvement test, sound pressure level (SPL500Hz) was 64.7dB at 69.0dB, the weighted sound level (SPLdB(A)) was 68.8dB(A) at 78.7dB(A), reverberation time (RT500Hz) was 1.28sec at 2.19sec, early decay time (EDT500Hz) was 1.48sec at 2.41 sec, definition (D50,500Hz) was 52.9% at 29.8%, clarity (C80.500Hz) was 2.2dB at -l.OdB, and RASTI was 584.4%(“Fair”) at 51.1%(“Fair”) was evaluated.
4,000원
12.
2024.12 구독 인증기관 무료, 개인회원 유료
In order to revitalize the marine leisure industry, researches on various leisure vessels have been widely conducted in Korea. In particular, in the field of leisure sports, researches and developments for improving the performance of high-speed motorboats are actively progressing. For reducing the weight of motorboats various composite materials are applied to the hull, and these composite materials must ensure structural safety. In this study, the material properties of composite materials applied to tunnel-type motorboats, used in the OSY(Outboard Stock Yamato)-400 race, were evaluated and the structural analysis was performed to examine the safety of the motorboat hull. Material tests were conducted according to Korean Industrial Standard and structural analysis of finite elements model of the motorboat hull was performed under longitudinal bending and torsional load conditions, respectively. By comparing the analysis results with the material test results, it was confirmed that the applied composite material meets the required strength.
4,000원
13.
2024.12 구독 인증기관 무료, 개인회원 유료
Magnesium alloys, among various non-ferrous metals, are utilized in diverse fields from the automotive industry to aerospace due to their light weight and excellent specific strength. In the previous Part I study, fiber laser BOP experiments were conducted to derive basic welding characteristics and appropriate bu竹 welding conditions. Subsequently, in the Part II experiment, butt welding was performed, and through tensile tests, hardness tests, and cross-sectional observations, it was found that at laser power of 2.0 kW and welding speed of 50 mm/s, 93% of the base metafs tensile strength and 63.4% of its elongation could be achieved. In this Part III experiment, the microstructures of the base metal and the center of the weld were observed in butt-welded specimens. Through this, laser power and welding speed, on the mechanical behavior and microstructure of magnesium alloys were analyzed
4,000원
14.
2024.12 구독 인증기관 무료, 개인회원 유료
This study developed a model to predict employee turnover intention using data from the 2022 Korean Labor & Income Panel Study (KLIPS) with 2471 participants. CopulaGAN and Isolation Forests were employed for data augmentation and variable importance. A logistic regression model using the augmented data achieved an accuracy of 0.80, precision of 0.60, recall of 0.72, and an F1-score of 0.65. Key variables included Job Satisfaction, Wage Satisfaction, Work Hours, Job Stability, and Job-Related Training. The study highlights the potential of these techniques for enhancing turnover prediction and aiding proactive HR strategies.
4,000원
15.
2024.12 구독 인증기관 무료, 개인회원 유료
This study analyzed IoT-based indoor air quality monitoring data in a cooking room at a high school in Seoul. As a result of measuring the type and concentration change of cooking fumes generated during roasting, frying, and stir-fry, each cooking method showed a different pattern. Some cooking fumes were observed high during the distribution process, not during cooking, and it is necessary to observe and control indoor air quality during the entire process of cooking, storage, and distribution as well as various elements of cooking fumes. Through these results, we propose the addition of an IoT-based real-time indoor air quality monitoring system and ventilation facilities linked to it.
4,000원
16.
2024.12 구독 인증기관 무료, 개인회원 유료
Automobiles are an essential means of transporting passengers and cargo, but traffic accidents are inevitable in their operation. These accidents can occur in various forms, such as front, rear, and side collisions. The resulting damage to the vehicle can also be seen similarly; it is inherently distinct: the complexity of repairing the car body makes a simple reliance on textbook knowledge insufficient. Successful correction of the damaged body largely depends on the experience of the practitioner. Discussions on body repair techniques should be based on empirical data reflecting current industry standards and associated costs. The variability of individual repair methodologies can result in significant time and financial expenditure in the field of automotive bodies. Application of new material technologies to vehicle fabrication requires continuous training and empirical research, especially on the body repair process involving new materials. In particular, since the left and right aprons and side members are made of different materials, such as aluminum and high-strength steel, careful restoration of these parts is required. Technical considerations are needed. Interest in safety and environmental impacts. In this study, SPR bonding technology analyzes experimental results.
4,000원
17.
2024.12 구독 인증기관 무료, 개인회원 유료
In the development of a digital multi-process welding machine, we aimed to analyze the heat dissipation effects resulting from changes in the transformer's shape. Two installation configurations for the transformer, vertical and horizontal, were proposed. Thermal-flow analysis was conducted for the welding machine, taking into account variations in spacing between each proposed configuration. The results indicated that the shape and spacing of the components did not significantly alter the airflow around the reactor coil, which is the main heat-generating component of the machine. When comparing the heat dissipation effects across models with different transformer spacings, it was observed that models with narrower spacing exhibited improved heat dissipation, while the vertical configuration demonstrated a slightly higher heat dissipation effect overall. Transient analysis revealed the irregularities in internal flow and the resulting scattered temperature distribution over time within the welding machine.
4,000원
18.
2024.12 구독 인증기관 무료, 개인회원 유료
This study investigates the structural stability of a telescopic arm designed for a painting robot through finite element analysis (FEA). As factory automation progresses, robots are increasingly used to replace hazardous tasks like painting. However, the heavy weight of telescopic arms poses significant control challenges. This research specifically examines the structural stability of a 7.4-meter telescopic arm, designed for use in a 14m x 14m large-scale block painting environment. The telescopic arm consists of six steel links, each ranging from 700 mm to 1500 mm, and supports a 50 kg painting robot mounted at the end of Link 6. Using Dassault System’s Abaqus2022 software, simulations were performed in both stretched and rotated modes to analyze self-weight effects and structural stability. The results revealed maximum deflection of 92.3 mm in stretched mode and 127.3 mm in rotated mode, with the highest stress concentration of 416.8 MPa occurring at the Link 3 and Link 4 connection. To improve stability, additional reinforcement materials and an increase in connector thickness from 40 mm to 80 mm were applied, successfully reducing maximum stress to 94.3 MPa. These findings suggest an effective enhancement in the stability of the telescopic arm under various operational modes.
3,000원
19.
2024.12 구독 인증기관 무료, 개인회원 유료
In this study, the pre-stress characteristics of magnetic rheological rubber, an intelligent material widely applied to mechanical systems, are measured. Intelligent materials are substances that change their properties in response to external inputs and are extensively used in mechanical systems. Magnetic rheological rubber is a representative intelligent material that can exhibit variable characteristics depending on the conditions. When measuring the physical properties of magnetic rheological rubber, it is placed in a magnetic field application device, where a magnetic field is applied, and the material is subjected to pre-stress. Similarly, when manufacturing intelligent mechanical systems using magnetic rheological rubber, pre-stress is induced by components used to apply the magnetic field. Generally, when a material is subjected to pre-stress, its properties change. Consequently, the performance of magnetic rheological rubber under pre-stress also varies. If the characteristics of the material under pre-stress change, the expected performance during design may deviate, leading to differences in the mechanical system's performance from the intended design. This variability makes it challenging to design mechanical systems based on intelligent materials, highlighting the importance of experimentally investigating their characteristics. Therefore, this study measures and identifies the pre-stress characteristics of magnetic rheological rubber under pre-stress. These findings can be applied to improve the measurement methods and design approaches for magnetic rheological rubber in pre-stressed conditions.
4,000원
20.
2024.12 구독 인증기관 무료, 개인회원 유료
This study aims to optimize the SDC (Spinning Dust Collector) system in amphibious assault vehicle engines through numerical analysis of dust and moisture particle separation efficiency using CFD-DPM. Focusing on an axial cyclone structure, the research evaluates separation efficiency across various particle sizes and flow conditions. The results demonstrate that vortices generated by cyclone blades play a critical role in influencing particle trajectories and improving separation performance. Additionally, the study highlights the significant impact of engine flow conditions and housing design, emphasizing that their careful optimization enhances the system's efficiency in separating dust and water. These findings offer valuable insights into optimizing inlet and outlet flow paths and cyclone housing design, providing a solid foundation for advancing SDC system performance in high-efficiency engines.
4,200원
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