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        검색결과 42

        1.
        2025.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, several types of torque distribution functions (TDFs) are presented for the instantaneous torque control of switched reluctance motor (SRM) drives. To verify the feasibility and effectiveness of the proposed TDFs, two different categories—parameter non-adaptive and parameter adaptive functions—are introduced and analyzed. These different types of TDFs are systematically implemented in instantaneous torque control schemes to enhance the performance of SRM drives. The proposed torque control method, incorporating these various TDFs, is modeled and simulated in PSIM software to validate the presented control schemes. Simulation results demonstrate the effectiveness of the proposed approach in achieving precise torque control and improving the dynamic performance of SRM drives.
        4,000원
        3.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently marine accidents involving floating objects have been continuously increasing due to domestic coastal traffic conditions, and as a result cases of secondary-linked reduction gear damage have also occurred one after another. This research aims to evaluate the ship propulsion system safety through the analysis the effect of the torsional stress generated on the propeller shaft system when a rope or net is wrapped around a propeller at sea through theoretical analysis, simulation analysis, and ship empirical test.
        4,000원
        4.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The demand for ceramic brackets, which have a high aesthetic purpose due to their high light transmission is increasing due to the application of poly-crystalline alumina material. Brackets using this material require stable properties that should not fracture during the treatment period. In this paper, the fracture strength of a ceramic bracket made of the same material used in clinical practice was checked by applying torque with a square stainless steel wire. The wire used in the test was prepared with cross-section sizes of 017 inch ✕ 025 inch, 018 inch ✕ 025 inch, and 019 inch ✕ 025 inch. There were a total of 150 bracket specimens and after ligating wires in the slots, torque was applied to each of 75 specimens in the gingival and occlusal directions. The torque test used digital torque meter equipment and the torque value at which the bracket slot fractured due to plastic deformation of the ligated wire was confirmed. Based on the resulting data we plan to use the data to recommend stable torque use and develop future bracket design.
        4,000원
        5.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In compliance with environmental regulations at sea and the introduction of unmanned autonomous ships, electric propulsion ships are garnering significant attention. Induction machines used as propulsion electric motor (PEM) have maintenance advantages, but speed control is very complicated and difficult. One of the most commonly used techniques for speed control is DTC (direct torque control). DTC is simple in the reference frame transformation and the stator flux calculation. Meanwhile, two-level and three-level voltage source inverters (VSI) are predominantly used. The three-level VSI has more flexibility in voltage space vector selection compared to the two-level VSI. In this paper, speed is controlled using the DTC method based on the specifications of the PEM. The speed controller employs a PI controller with anti-windup functionality. In addition, the characteristics of the two-level VSI and three-level VSI are compared under identical conditions. It was confirmed through simulation that proper control of speed and torque has been achieved. In particular, the torque ripple was small and control was possible with a low DC voltage at low speed in the three-level VSI. The study confirmed that the application of DTC, using a three-level VSI, contributes to enhancing the system's response performance.
        4,000원
        7.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to analyze the difference between the theoretically calculated torque values of lead screws used in vehicle seat rails and the required torque values due to various disturbances that occur in actual systems. Lead screws were classified into square and trapezoidal threads and modeled by two lead type. Dynamic analysis models were constructed by applying contact conditions and rotational joints between the lead screw and nut. The validity of the dynamic model was verified by comparing the torque values obtained from rigid body dynamic analysis with the theoretically calculated torque values. Then, the lead screw was modeled as a flexible body to investigate the torque variation required for the lead screw when dynamic loads are considered. This study will help predict the actual torque values of lead screws for seat rails.
        4,000원
        9.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents the torque ripple reduction control to apply an SRM to the X-by-wire drive systems which replaces the mechanical control method with “by-wire” to secure the flexibility of design and modification. However, torque ripples generated from the SRM can affect the performance and stability of the system. The proposed torque ripple control schemes are compared with the previously studied methods by dynamic simulation in regards to torque distribution functions and instant torque controller.
        4,000원
        10.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LDV(laser Doppler velocimetry) measurements were conducted at a total of four planes at 0.4 speed ratio. The speed ratio of 0.4 is 1600rpm of impeller and 633rpm of turbine speed. Even at the speed ratio 0.4, fluid flow at the gap region between the impeller and turbine and impeller exit was leaving the impeller and flowing up behind the turbine, and flows were affected by the turbine blade as it passed, negatively effecting converter efficiency. In the gap region, fluctuations make a clear sinusoidal trend unclear. The rise and fall of the flow rates in a broad sense, indicate a dependency based on the passage of the turbine blade in front of the impeller passage exit but a sinusoidal trend is not evident from this data.
        4,000원
        11.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to investigate the effect of torque variation on stress distributions in A-IMS module with both side tubular shaft yoke by numerically. In order to achieve this, the torque value was increased from 10Nm to 40Nm, and the results of this work were confirmed in terms of Von-mises Stress and the displacement characteristics. As the torque in module assembly was increased, the stress in tubular shaft york and splined shaft york was increased linearly. The indentation due to the steel ball was occurred in over 40N·m torque which is over the yield strength condition. The largest displacement occurred in the tubular shaft yoke 1, however, it does not exceed the yield strength and is supposed to be restored due to the elasticity. Therefore, it was concluded that there is no problem for the manufacturing of A-IMS with both side tubular shaft yoke.
        4,000원
        12.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LDV(laser Doppler velocimetry) measurements were conducted on the exit region of the impeller passage and the gap between the impeller and turbine blades under 0.8 speed ratio. The 0.8 speed ratio has an impeller speed of 2000rpm and a turbine speed of 1600rpm. A periodic variation of the mass flow rate is present in many of the measurements made. The frequency of this variation is the same as the frequency of the turbine blades passing the impeller passage exit. It is found that the instantaneous position of the turbine had effect on fluid flow inside the impeller passage and gap region. This study would aid in the construction of higher accuracy CFD models of this complex turbomachinery device.
        4,000원
        13.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to design and control position and torque based on the steering controller of power tiller simulator developed by the National Institute of Agricultural Sciences. The tiller simulator selects sensors and motors to detect the motion of the mechanism required for steering, and controls the tiller's steering controller through the PID control method and the PWM control method which can control simultaneously the position and torque. Simulation tests are carried out under various conditions to verify the efficiency of the proposed controller. The power tiller training simulator can be used as a means to prevent agricultural machinery accidents caused by human factors. Through the simulator, the driver can experience a variety of tasks without any risk of collision, the results of his actions, and learn the cause and effect concepts, which can be used for safety education and accident experience.
        4,000원
        14.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed for the optimizations of A-IMS assembly by analyzing the stress distributions under the different torque conditions. In order to achieve this, the numerical simulation was performed by SOLIDWORKS commercial code and the torque range that applied on the A-IMS assembly was increased from 10 N·m to 40 N·m. The simulation results were analyzed and compared in terms of Von-mises stress, principal stress, and displacement characteristics. The maximum stress distributions was observed on the contact surface of needle bearing which is located between tubular and solid shaft. It was found that the fracture of A-IMS assembly won’t occur until 30 N·m of torque. Therefore, it was concluded that there is no problem for the manufacturing of A-IMS assembly.
        4,000원
        16.
        2016.04 구독 인증기관·개인회원 무료
        The clamping of torque shear high strength bolt is induced when the pin-tail is broken. However the tension forces induced shank of the bolt do not be known by now. This study focused to develop a quantitative method to identify the induced tension by analyzing the electric energy of which electric torque wrench (rpm 20) was applied to high strength bolt at the break of pin tail. Based on this co-relation between tension and accumulated current, the regressive analysis was derived. The error rate between tension and accumulated current was 5.06%.
        17.
        2016.04 구독 인증기관·개인회원 무료
        The clamping of torque shear high strength bolt is induced when the pin-tail is broken. However the tension forces induced shank of the bolt do not be known by now. This study focused to develop a quantitative method to identify the induced tension by analyzing the electric energy of which electric torque wrench was applied to high strength bolt at the break of pin tail. Based on this co-relation between tension and accumulated current, the regressive analysis was derived. The error rate between tension and accumulated current was 2.24%.
        18.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Shin, Yu-Ri. 2015. “Nonverbal Discourse Strategies of Korean TV Talk Show Hosts: Focus on ‘Nodding’ and ‘Bending’”. The Sociolinguistic Journal of Korea 23(1). 115~143. As our speech builds on verbal as well as nonverbal elements, we perform discourse strategies through both of them in interaction. This study takes a closer look at the nonverbal strategies performed during talk show discourse as seen on Korean television. By taking into account the sociocultural context on which both talk show hosts and guests mutually rely in their interaction, the paper examines how this shared pool of sociocultural resources affects the discourse strategies of the hosts. This holds particularly true for Korean TV talk shows, since the social relationships, from which the discourse participants draw, is defined and reflected in the shows' semi-institutional character. Throughout the show, the host makes use of nodding and bending on an interpersonal, semantic, and structural level. In this order, such discursive functional devices serve a distinct politeness strategies and can, therefore, be determined as discursive strategies.
        6,900원
        19.
        2015.03 구독 인증기관 무료, 개인회원 유료
        This study is designed to measure the impact of a car’s horse power and torque - aspects related to performance among various factors that affect consumer purchase decision-on consumers when buying a car. The research of the results can be interpreted as indicating that the premise, “The impact of torque and horsepower on consumer purchase decision is not significant,” is true.
        4,000원
        20.
        2015.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The general auto transmission uses the torque converter that has a good vibration damping force by launching performance and damping effect as power transfer unit. The vehicle equipped with auto transmission uses Lock up clutch system to improve the fuel efficiency. The Lock up clutch system is the major factor of the devices that increase the torque from engine to transmission in specific condition and also consist of the damper springs to transfer the torque stably. Damper spring controls the vibration of power transfer units and improve the impression of riding and durability, by being damping function on change torque from engine. In addition, not only the appearance and performance, but also these sensitive qualities as like vibration and noise can also be main factor to buy a car. Recently, in order to absorb the low vibration caused by vehicle structure vibration, the Low-stiffness damper has been on the rise. The damper spring should be considered and designed, considering the engine characteristic and direct connect of lock up clutch due to the stiffness of the spring and hysteresis has a major effects to the damper characteristic. This study can be used for analyzing the major factors to effect the NVH characteristic by evaluating the damper’s hysteresis according to change of spring stiffness.
        4,000원
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