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
제22권 제6호 (2020년 12월) 30건
21.
2020.12
구독 인증기관 무료, 개인회원 유료
In this paper, the goal is to obtain a dynamic model of a particular system. The system is a combination of a wheeled vehicle(chassis) with a turret rotating in azimuth direction and a gun rotating in a elevation direction. At this time, the motion of the gun according to the shaking of the continuous shot is obtained using the coordinate transformation equation in the azimuth and elevation angle. Also, the dynamic model for the swaying of wheeled vehicle is obtained through the Lagrange’s equation. Through this, we analyze the tumbles of the gun, whiat is the major term, and what dynamics are needed for stabilization control.
4,000원
22.
2020.12
구독 인증기관 무료, 개인회원 유료
This study is a basic study to improve fuel economy and reduce harmful emissions from passenger cars. This study is a basic study to evaluate the performance of fuel oil additives. The performance may vary depending on the type of engine, the region of use, and the driving habits of the user. Therefore, there are many difficulties in carrying out the test analysis by the objective experimental method while maintaining the same conditions. Therefore, this study intends to examine in terms of securing objectivity as a comparative study by the measurement of single user for a long time. As a result, in the case of cars using gasoline engines, the fuel economy tended to a little decrease as the distance-age increased. However, in the analysis of diesel vehicles by year, it increased gradually after the 5th year and the distance-age of 60,000km. And a comparison of the last three years, an increase of about 3.1% from 12.44km /ℓ to 12.82km /ℓ.
4,200원
23.
2020.12
구독 인증기관 무료, 개인회원 유료
This paper reports critical heat flux(CHF) performance on wire heater according to material, thickness, length, cross sectional shape. Water was employed as the working fluid, which was saturated at 1 atm. By comparison of CHF values with difference conditions of wire length, contact resistance inherent in the experimental apparatus could be analyzed, which had made the bias error in many research groups. So, exact value of CHF could be measured, which was consistent with the literatures. The CHF value showed decrease tendency, as the cross sectional area increased and reach to the capillary length of the working fluid. Meanwhile, the effect of thermal properties on CHF was not observed in the experimental cases. This data would be used as a reference data in research field of CHF using wire heater, i.e. reactivity initiative accident(RIA).
4,000원
24.
2020.12
구독 인증기관 무료, 개인회원 유료
In this study, visualization of droplet impact on hydrophobic micro-, micro/nano-textured surfaces and lubricant infused surfaces was performed. Experimental specimens were fabricated using MEMS (micro- electromechanical systems) techniques and droplet impact with pure water was visualized at various Weber number range (2 < We < 200) using a high speed camera at 8000 frames per second. Through this study it was confirmed that, various droplet impact behaviors were appeared as the Weber number was increased and the Weber number at which droplet impact behavior changes was affected by surface characteristics. Particularly, on the lubricant infused surface (LIS) after droplet impact retraction velocity is reduced by the lubricant viscosity effect during contraction process of droplet to improve the droplet deposition behavior on the surface. It was confirmed that droplet break up phenomena caused interfacial instability was slightly delayed on LIS due to the viscous dissipation effect during droplet impact process.
4,000원
25.
2020.12
구독 인증기관 무료, 개인회원 유료
In this study, experiments and simulations were performed for fillet joint friction stir welding according to tool shape and welding conditions. Conventional butt friction stir welding has good weldability because heat is generated by friction with the bottom of the tool shoulder. However, in the case of fillet friction stir welding, the frictional heat is not sufficiently generated at the bottom of the tool shoulder due to the shape of the tool and the shape of the joint. Therefore, it is important to sufficiently generate frictional heat by slowing the welding speed as compared to butt welding. In this study, experiments and simulations were carried out on an aluminum battery housing made by friction stir welding an extruded material with a fillet joint. The temperature of the structure was measured using a thermocouple during welding, and the heat source was calculated through correlation analysis. Thermal elasto-plastic analysis of the structure was carried out using the calculated heat source and geometric boundary conditions. It is confirmed that the experimental results and the simulation results are well matched. Based on the results of the study, the deformation of the structure can be calculated through simulation even if the tool shape and welding process conditions change.
4,000원
26.
2020.12
구독 인증기관 무료, 개인회원 유료
Plastic products molded by injection molding have become an essential element of our lives. In addition, plastics can replace parts that used to be metal in the past. Plastic molded products used as a part of a mechanical system require high precision. At the same time, the appearance quality of molded products is also an important evaluation factor. The appearance quality of a molded product is affected by injection molding conditions, plastic material fluidity, and the condition of the mold surface. In this study, the cause of the short shot of the dog house, which functions to assemble the plastic tailgate parts for automobiles, was analyzed. In order to solve the short shot problem of the dog house, the root thickness of the dog house, injection molding conditions, and fluidity of plastic materials were experimented. Through the injection molding experiment, it was found that when the dog house root thickness was increased from 0.8mm to 1.2mm, the filling amount of the doghouse part increased by 43% in experiment mold. These results were verified by injection molding analysis.
4,000원
27.
2020.12
구독 인증기관 무료, 개인회원 유료
This study is developed a self-propelled Welsh onion harvester to increase farm household income by mechanizing the labor-intensive Welsh onion harvesting operation. In order to evaluate the performance of the developed harvester, the work capacity, damage rate, and harvest rate are investigated for three traveling speed levels (7.3cm/s, 12.3cm/s, 19cm/s). Work capacity is increased proportionally to 1.8a/hr, 3.1a/hr, and 4.9a/hr, respectively, as the traveling speed increased. And the damage rate also is increased in proportion to the traveling speed, and under the same conditions, it is increased proportionally to 2.9%, 3.9%, and 4.4%, respectively. The harvest rate is 100% at all speeds of the Welsh onion harvester. The developed harvester is expected to greatly contribute to improving the cultivation environment of Welsh onion by enabling mechanization of the harvesting operation with the largest amount of labor during the Welsh onion production.
4,000원
28.
2020.12
구독 인증기관 무료, 개인회원 유료
In recent years, on average, 270 domestic marine pollution accidents are occurring a year and especially, damage by oil outflow accidents is extremely serious. These large-scale oil outflow accidents bring about a very huge damage to marine living resources and recovery of nature and it takes a long period of time to restore. Therefore, this study aims to examine the increase in the marine pollution control staff over the last decade focusing on the Maritime Pollution Response Bureau that is an organization affiliated to Korea Coast Guard run by the state and compare the number of marine accidents and marine pollutant outflow. Over the past decade, the pollution staff has increased to 110, which is 30 percent higher than the total number of employees and excepting the large-scale outflow accident of a specific year, the outflow has slowly decreased by nearly 55 percent. Although marine pollution accidents have partially grown, most of them are slight careless faults in small fishing vessels with a weight of 50 tons or under. In conclusion, the increase in the marine pollution control staff has led to the decrease in outflow, which means obviously, increasing the marine pollution control staff has had a positive influence on improvement in marine pollutant outflow.
4,000원
29.
2020.12
구독 인증기관 무료, 개인회원 유료
Metal bodies have generally been produced through machining process, even the smallest parts that are assembled and mounted on the metal body. In this study, we will study the process of manufacturing parts called SIM Tray through compound forging process instead of cutting. The process of replacing a series of SIM Tray production process with a composite forging process by simulating the forming process using DEFORM-3D and making process design, mold design, mold fabricating.
4,000원
30.
2020.12
구독 인증기관 무료, 개인회원 유료
Recently, the annual emission rate of CO2 that is the main reason for domestic greenhouse gases is the third highest globally, which means it is an extremely serious issue. It is considered that these greenhouse gases affect climate changes. Especially, the emissions of CO2 in the fishing industry are nearly 4.11 million tons each year, occupying 0.7 percent of domestic total emissions. Therefore, this study clearly analyzed fuel consumption of major fish species over the recent five years focusing on large purse seines. It was revealed that mackerels occupied 55.7 percent of total fish catches of large purse seines and 57.5percent of total fishing earnings. Also, fuel consumption was 236.62 liters per ton caught and 179.51liters per million won earned.
4,000원
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