간행물
한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌
- 발행기관 한국기계기술학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1229-604X (Print)2092-0385 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 기계공학 공학 분류의 다른 간행물
- 십진분류KDC 550DDC 620
권호리스트/논문검색
제24권 제2호 (2022년 4월) 24건
1.
2022.04
구독 인증기관 무료, 개인회원 유료
The styling of automobile wheels and their effect on vehicle appearance has increased in importance in recent years. The wheel designer has been given the task of insuring that a wheel design meets its engineering objectives without affecting the styling theme. The wheel and tire system is considered as a vehicle component whose dynamic modal information of the tire/wheel system are employed in the modal synthesis model of the vehicle. The Modal characteristics of a Automobile wheel play an important role to judge a ride comfortability and quality for a Automobile. In this paper, the modal characteristics of a Al-alloy and steel wheel for Automobile are studied. Natural frequency, damping and mode shape are determined experimentally by frequency response function method. Results show that wheel material property, size and design are parameter for shift of natural frequency and damping.
4,000원
2.
2022.04
구독 인증기관 무료, 개인회원 유료
The role of QR Code robots in smart logistics is great. Cognitive robots, such as logistics robots, were mostly used to adjust routes and search for peripheral sensors, cameras, and recognition signs attached to walls. However, recently, the ease of making QR Codes and the convenience of producing and attaching a lot of information within QR Codes have been raised, and many of these reasons have made QR Codes recognizable as visions and others. In addition, there have been cases in developed countries and Korea that control several of these robots at the same time and operate logistics factories smartly. In this work, we are developing a robot that can recognize its current position, move and control in the directed direction through two-dimensional QR Codes with the same horizontal and vertical sides, and the error is to create a QR Code robot with accuracy to reach within 3mm. This paper focuses on experimental environments for testbeds during the development of QR Code-aware indoor mobility robots.
4,000원
3.
2022.04
구독 인증기관 무료, 개인회원 유료
The performance characteristics and usefulness of the duct-type gas removal system to which the catalytic combustion method was applied were investigated by experiment. Benzene, toluene, ethylbenzene, and xylene were selected for performance tests on gas detection and removal of the catalytic combustion system. Accelerated experiments were performed to evaluate the gas sensing performance, the adsorption performance of activated carbon, and the basic performance and durability of the catalytic combustion system. The amount of gas adsorption in the adsorption stage was changed according to the type of activated carbon, adsorption temperature and time. The adsorption amount increased with increasing temperature and particle size. BTEX gas removal rate was about 96%, and the performance of the module was maintained for more than 4,000 hours.
4,000원
4.
2022.04
구독 인증기관 무료, 개인회원 유료
In the event of an defective wire in the low-speed CAN communication of vehicle, the problem had to be solved by relying on fault codes or using expensive measuring equipment. An experiment was conducted to analyze waveforms of communication circuits with wire conditions such as normal, short circuits in the main body, and mutual short circuits. When the controller drives the CAN transceiver and transmits a message, the voltage and current waveforms were measured using an OEM oscilloscope to check for abnormalities in the circuit. As a result, it was confirmed that when a defective wire occurs in low-speed CAN communication, the CAN driver can switch to the fail-safe mode to exchange normal messages.
4,000원
5.
2022.04
구독 인증기관 무료, 개인회원 유료
Various kinds of friction materials were manufactured by adding 10%, 20%, and 30% of reduced iron, respectively, which has been obtained during the reduction process of blast furnace sludge extracted from the blast furnace, and its iron oxide, instead of existing barium sulfate(BaSO4) among the components of automobile brake friction materials. Fundamental physical property test and friction performance test, etc., using a brake dynamometer were carried out against these friction materials. Furthermore, when the expensive filling material, BaSO4 was substituted by reduced iron and added to the friction material, the added content of reduced iron for an excellent friction characteristic considering the heat emission temperature, wear, etc., was 10%. In the fundamental physical property test, as the added content of blast furnace sludge or reduced iron increased, and as the content increased, the shear strength and bonding strength of friction materials decreased, but both of them indicated sufficient strengths to be applied to a friction material. Even in the frictional performance test using a brake dynamometer, as the added content of blast furnace sludge or reduced iron increased, the friction coefficient reacted insensibly to brake deceleration, and its stability was improved.
4,000원
6.
2022.04
구독 인증기관 무료, 개인회원 유료
A Catholic school is a school that spreads religious ideology to students by combining religious education with regular school curriculum. But, most Catholic schools do not have a separate liturgical space, mass is performed in multipurpose spaces such as auditoriums, and are exposed to severe acoustic defects due to the very aging facilities and lack of sound performance suitable for the liturgical space. So, in this study, an improvement plan was proposed using sound simulation after identifying acoustic defects through field measurements in the liturgical space of Haeseong High School in Jeonju. Also, hearing experiment using Acoustic Psychological Analysis was conducted to identify changes in subjective responses felt by students as they improved their acoustic performance. The results of study, before and after sound performance improvement sound pressure level(SPL500Hz) was 64.8dB at 66.7dB, the weighted sound level(SPLdB(A)) was 67.9dB(A) at 75.8dB(A), reverberation time(RT500Hz) was 2.04sec at 2.52sec, definition(D50,500Hz) was 40.2% at 33.5%, clarity(C80.500Hz) was –0.8dB at –1.18dB, and RASTI was 57.7% at 49.2% was evaluated. In addition, the amount of improvement in subjective responses before and after sound performance through psycho-acoustic experiment decreased by “Reverberation” -17.0%, “Loudness” -11.3% and increased by “Clear” 21.3%, “Vivid” 21.3%, “Intimacy” 12.4%, “Warmth” 14.3%, “Stability” 19.3%, “Godliness” 18.8%. Therefore, after improving sound performance, Haesung High School's liturgical space improved satisfaction with subjective sound performance felt by students and teachers to ensure sound performance suitable for the liturgical space.
4,800원
7.
2022.04
구독 인증기관 무료, 개인회원 유료
Interest in the rammed construction method using eco-friendly materials is increasing in modern architecture. However, the work of construction is not convenient and will require a lot of manpower and time. This study proposes an automation compactor consisting of a compactor frame, crank arm, servo motor, wire, and a compactor hammer. The compactor hammer is fixed on the wire to achieve up-down movement by servo motor. And the state of up-down movement of the proposed compactor in 4 steps was had a dynamic analyzed. Through the actual compression experiment, the reliability of the proposed compactor is verified and is expected to be used in rammed earth construction.
4,000원
8.
2022.04
구독 인증기관 무료, 개인회원 유료
Due to the environmental regulations of the International Maritime Organization (IMO), the number of ships using cryogenic fuel such as LNG (liquefied natural gas) is increasing rapidly, and the demand for eco-friendly ships is expected to grow further in the future. The material of the tank for storing cryogenic fuel such as LNG is limited within the IGC Code, and available materials include 9% nickel steel, Invar (36% nickel steel), Al5083-0, STS304L, and high manganese steel. Recently, 9% nickel steel has been used as a tank in LNG fuel-powered ship projects, and it has excellent thermal/mechanical properties in cryogenic LNG environmental conditions (-163°C). In this study, it is conducted an experimental study on SAW(Submerged Arc welding), which has better welding efficiency than FCAW(Flux Cored Arc Welding), which is mainly used for 9% nickel steel materials. In addition, to verify the reliability of the welded part after the welding test, cross-sectional observation of the welded part was performed and the mechanical properties such as the tensile strength and cryogenic impact strength of the welded part were evaluated.
4,000원
9.
2022.04
구독 인증기관 무료, 개인회원 유료
A microfluidic pump is a key component to controllably actuate fluids in Lab on a chip devices. To overcome technical issues of a diaphragm-type pump, a valveless nozzle-diffuser type pump was developed by utilizing the different flow resistance to control a dominant flow direction by means of diaphragm actuation. In this work, based on the operating mechanism of the nozzle-diffuser type pump, we propose a new concept of a valveless pump which can generate asymmetric flow through a pump chamber. In the proposed valveless pump, asymmetric flow path structures play a role of a nozzle-diffuser installed to a pump chamber. To validate the concept of the proposed valveless pump, we conducted CFD simulations for different geometries of the flow path structures. Based on the CFD simulations, we found that the dominant flow direction can be selectively manipulated by the pump actuation and an optimal shape of the asymmetric flow path structure was proposed to maximize the net mass flow rate through the pump chamber.
4,000원
10.
2022.04
구독 인증기관 무료, 개인회원 유료
Thick-walled pressure vessel has been autofrettaged in order to improve the fatigue life of the pressure vessel. The compressive tangential residual stress near the bore of the pressure vessel due the autofrettage process is benefical to the fatigue crack initiation and propagation of the pressure vessel. However, a reverse yielding due to the Bauschinger effect during the unloading process in autofrettage causes the reduction of the compressive residual stress near the bore. In order to evaluate the fatigue crack propagation life of the autofrettaged thick-walled pressure vessel, the Bauschinger effects were considered. Stress intensity factors of the crack at the inside surface of the pressure vessel due to operating pressure loading of 707 MPa and autofrettage loading with different levels of overstrain were calculated by using finite element methods, and used for evaluating fatigue crack propagation lives. Fatigue lives of the pressure vessel with the Bauschinger effects resulted in 45% to 67% reductions in fatigue life compared to those of the pressure vessel with ideal residual stress distributions depending on the autofrettage level.
4,000원
11.
2022.04
구독 인증기관 무료, 개인회원 유료
Valves are one of the indispensable components in modern industry. Filling and de-pressure connectors in rocket valves used for space launch vehicles are very important parts for smooth fluid supply. For this reason, an optimized design that can improve efficiency, miniaturization, weight reduction, and safety of the valve at the same time is required. In this work, flow analysis and structural analysis were performed through 3D modeling using computational numerical analysis for open type filling and de-pressure valves. As results, the flow velocity and pressure distribution of the fluid were analyzed through the flow analysis of valve, and stress distribution was conducted in structural analysis. Through this study, it is consequently expected to provide valves of various specifications by performing production and performance test evaluation of development prototypes.
4,000원
12.
2022.04
구독 인증기관 무료, 개인회원 유료
The use of heat exchangers in various applications such as chemical, air conditioning systems, fuel processing, and power industries is increasing. In order to improve the performance of the heat exchanger, the problem of bonding quality of the copper tube, which is a major member, is emerging. However, since the copper tube is in the form of a pipe, it is difficult to identify internal defects with external factors. In this study, a thermal imaging camera was used to develop and verify an algorithm for detecting defects in the brazing part, and in the process, the brazing performance characteristics were analyzed according to the electrode position, and finally, a learning model was developed and performance evaluation was performed. It was confirmed that the method of supplying heat to the base material and melting the filler metal through the heat transfer effect is more effective than supplying heat input to the filler metal in the bonding process of copper tubes through high-frequency induction heating brazing. Thermal image data was used to develop a defect discrimination model, and 80% of training data and 20% of test data were selected, and a neural network-based single-layer copper tube brazing defect discrimination model was developed through k-Flod cross-validation., the prediction accuracy of 95.2% was confirmed as a result of the error matrix analysis.
4,000원
13.
2022.04
구독 인증기관 무료, 개인회원 유료
Along with the current rapid development of technology, object classification is being researched, developed, and applied to security systems, autonomous driving, and other applications. A common technique is to use vision cameras to collect data of objects in the surrounding environment. Along with many other methods, LiDAR sensors are being used to collect data in space to detect and classify objects. By using the LiDAR sensors, some disadvantages of image sensors with the negative influence on the image quality by weather and light condition will be covered. In this study, a volumetric image descriptor in 3D shape is developed to handle 3D object data in the urban environment obtained from LiDAR sensors, and convert it into image data before using deep learning algorithms in the process of object classification. The study showed the potential possibility of the proposal and its further application.
4,000원
14.
2022.04
구독 인증기관 무료, 개인회원 유료
In this study, the multi-lane detection problem is expressed as a CNN-based regression problem, and the lane boundary coordinates are selected as outputs. In addition, we described lanes as fifth-order polynomials and distinguished the ego lane and the side lanes so that we could make the prediction lanes accurately. By eliminating the network branch arrangement and the lane boundary coordinate vector outside the image proposed by Chougule’s method, it was possible to eradicate meaningless data learning in CNN and increase the fast training and performance speed. And we confirmed that the average prediction error was small in the performance evaluation even though the proposed method compared with Chougule’s method under harsher conditions. In addition, even in a specific image with many errors, the predicted lanes did not deviate significantly, meaningful results were derived, and we confirmed robust performance.
4,000원
15.
2022.04
구독 인증기관 무료, 개인회원 유료
The ship security accidents that occur in ships, at sea, and in ports have become increasingly more serious in recent years, and in particular, maritime terrorism and the abduction by pirates are emerging as an international problem. Accordingly, the International Maritime Organization implemented a measures to enhance ship security by adopting SOLAS Chapter 11-2, ISPS-code in 2004. In this study, it was investigated whether JDS-S4, a directional sound receiver developed for responding to ship security accident, has durability and safety suitable for ships. For the purpose, the conducted emission test (CE102) of the US military standard test (MIL-STD-461F) was performed, and it was confirmed that JDS-S4 satisfies the test conditions sufficiently.
4,000원
16.
2022.04
구독 인증기관 무료, 개인회원 유료
The waterpower generation of the dam generates electricity by revolving the turbine through a water pipe using the difference of high/low of water, the revolving turbine makes an occurrence a terribly loud noise. Accordingly, in the water turbine generator room located on such hydroelectric generator, since a mutual communication is not establish properly when working, they are suffering many difficulties, and it is real state that such noise damages even to those workers in the office of power plant. Since the most of dam water turbine generator room built in domestic country had used the finishing materials of a huge volume and a high reflexibility, it is carrying more amplifying function with the turbine noise arising when generates the electricity. Therefore, there is not only a difficulty for mutual communication among those workers in the workplace, but also it becomes an obstruction factor for working even to the workers in the adjacent office, and because they are suffering the mental and physical damages, it is actual state that a noise-reduction measure is urgently needed. As a result of the study, on the object with the dam hydraulic turbine dynamo room in which an acoustic defect is being occurring, this Study has conducted the Psycho-Acoustics Experiment about the Delivery of Voice Information using Auralization Technique that can experience the Virtual Acoustic Field. It is considering that such study result could be used usefully for improvement of the Voice Definition when construction the dam hydraulic turbine dynamo room, in the future.
4,000원
17.
2022.04
구독 인증기관 무료, 개인회원 유료
In this study, stiffness evaluation was conducted on the main member, front cross member, and rear cross member, which are three components of sub-frame for SUVs (sports utility vehicles), through mode analysis. As for the design variables used in the analysis, the maximum frequency was examined by varying the width and height of each of the three parts into four types. Of course, the weight at this time is minimized, and the mode is set as a constraint that only bending occurs and no distortion occurs. As a result of the analysis, the member affecting the 1st mode was the rear cross member, and the member having the greatest influence on the 2nd mode was the front cross member. In addition, the member with the greatest influence on the 3rd mode appeared as the rear cross member, indicating that this part had the greatest effect on the bending stiffness.
4,000원
18.
2022.04
구독 인증기관 무료, 개인회원 유료
In this study, magnetic characteristics of two models of permanent magnet actuator applied and used in the Recloser were studied, and the new model design was verified using numerical analysis on the operation and current characteristics of the magnet actuator accordingly. Such as the Recloser require fast operation characteristics to open the fault current, so when the moving and fixed contacts of a magnet actuator with permanent magnets that generate holding force come into contact, a high holding force is required, and when it open to circuit, the magnetic force is rapidly reduced. It demands very high performance. Therefore, the speed characteristics and current characteristics of the contact points of the magnet actuator for which the design was completed were compared.
4,000원
19.
2022.04
구독 인증기관 무료, 개인회원 유료
The purpose of this paper is to propose part management and standardization to reduce cost and increase compatibility of parts through standardization and standardization of parts to be applied to urban air mobility(UAM) systems, Personnel Air Vehicle(PAV), Vertical Take-Off and Landing (VTOL), and so on. In other words, parts used in the urban air transportation system must be verified from the initial design stage in accordance with the aviation standard, and a systematic management system for various parts must be established to secure stability and improve quality. Therefore, as a system similar to the aviation component management system, it should be thoroughly managed for urban aviation components.
4,000원
20.
2022.04
구독 인증기관 무료, 개인회원 유료
This research studied faults that may occur during slow charging using the J1772 adapter of Tesla Model-3 electric vehicles. When the AC terminal was instantaneously disconnected, charging was performed normally when an AC circuit with disconnection up to three disconnection times was connected. Charging control was suspended when the number of disconnection reached four times. However, if the AC disconnection time exceeded 22 seconds, the charging control was stopped regardless of the number of disconnection. When a contact failure occurred at the AC terminal, high surge current and noise occurred. However, when the contact improved, the charging control continued. In terms of safety, it seems necessary to take measures such as stopping charging control when detecting noise.
4,000원
1
2
