• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.726-733
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• 2017

A magnetic shutter gear is a device that transfers mechanical power by synchronizing the magnetic field between permanent magnet layers facing circumferentially through a harmonic modulator. However, magnetic gears uses many rare-earth permanent magnets to guarantee comparable torque density to that of mechanical reducer. Hence, we propose a novel axial magnetic gear with a dramatically reduced number of permanent magnets and a closed magnetic path. The torque of the system was compared to that of an existing shutter gear through a harmonic analysis of the air-gap magnetic field. The modulator thickness and open ratio were considered as the primary design parameters, and the cogging effect was analyzed for variation of the reduction ratio. A dynamic model between the high-speed side and low-speed side was derived, and position control was performed for a constructed hardware implementation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1620-1625
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• 2015

In this study, a variety of industrial gears, shafts, chains, rollers, mold, etc. are widely used inautomotive steel carbon steel for machine structural SM45C typical material used for the experiments. In order to cure the surface of the test piece after the rough grinding and fine grinding was performed in order polishing. Perform the surface hardening of SM45C lacal area by using a diode laser. The output of the laser diode and the feed rate to the process variable. Micro-hardness testing, microstructure testing, scanning electron microscope testing(SEM), the heat input to the analysis. After analyzing the experiment to compare the mechanical properties of the material. When using a diode laser to assess the soundness of the surface hardening. Accordingly, the process for deriving the optimum demonstrate the feasibility.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.235-242
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• 1985

The mechanics of the walking shrimps is useful to clarify the fishing mechanisms in relation to the fishing gears. The gaiting behaviour concerning step positions and step timings on the flat board and the nettings, 16, 23 and 37mm in mesh size were experimented in the aquarium using video camera from June to October, 1984. It was found that the irregular movements of walking legs in step positions and step patterns were appeared on the nettings more than the flat surface due to the absence of mechanical contact with the substrates. The mean stride length and coefficient of variation of the periods in the walking shrimps on the flat board were significantly different from those values on the nettings, However, the velocity, the period and the ratio of forestroke to backstroke were unsteadily changed with the carapace length, and showed little difference under the four conditions. The mean phase difference on the flat board was greater than those values on the nettings which were decreased, while standard deviation on the flat board was smaller than those values on the nettings which were increased with increasing in mesh size.

• Cartoon and Animation Studies
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• s.31
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• pp.249-266
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• 2013

The purpose of this research is to study a case of the minimalism on Game Graphic User Interface design in Computer game. It is to analyse the minimal tendency on Game Graphic User Interface design in several Computer games such as Prince of Persia, Mirror's Edge, Splinter Cell, Gears of War, Call of Duty4, Metro 2033, Crysis2. These games expanded the field of Game Graphic User Interface design with the unique form of minimalism. Minimalism came from the formative arts in the 1960s and influenced to other fields of art. It seems to be an expression of various styles that promptly meet the needs of the times. Therefore, in this research, I would highlight the phenomenon of minimalisation in Game Graphic User Interface design and research the influence of Minimalism that appears in modern design focused on "simplicity" and "minimum" which are representative trend of Minimalism.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.709-716
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• 2007

An active steering bogie has been theoretically proved to improve both stability and steering performance remarkably. However, It has not been commercialized yet even though many researchers have been trying to develop it because some technical difficulties still exist such as information acquisition fer active control, increasing mechanical components, high energy consumption, fail-safe problem and so on. To solve those problems, an advanced active steering mechanism is proposed in this paper. With this mechanism, required control force is small enough to use direct drives. Therefore, the number of additional mechanical components can be minimized since mechanical transducers like gears are not necessary. Fail-safe function can be also inserted easily. In this paper, concept design of the proposed active steering bogie is introduced and the possibility is verified through computer simulation using linear dynamic model.

• The KSFM Journal of Fluid Machinery
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• v.10 no.3 s.42
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• pp.47-54
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• 2007

A rotordynamic analysis was performed with a dry vacuum pump, which is a major equipment in modem semiconductor and LCD manufacturing processes. The system is composed of screw rotors, lobes picking air, helical gears, driving motor, and support rolling element bearings of rotors and motor. The driving motor-screw rotor system has a rated speed of 6,300rpm, and was modeled utilizing a rotordynamic FE method for analysis, which was verified through the results of its 3-D finite element model. As loadings on the bearings due to the gear action were significant in the system considered, each resultant bearing load was calculated determinately and indeterminately by considering the generalized forces of the gear action as well as the rotor itself. Each resultant bearing loading was used in calculating each stiffness of rolling element bearings. Design goals are to achieve wide separation margins of critical speeds and favorable unbalance responses of the rotor in the operating range. Then, a complex rotordynamic analysis of the system was carried out to evaluate its forward synchronous critical speeds, whirl natural frequencies and mode shapes, and unbalance responses under various unbalance locations. Results show that the entire system is well designed in the operating range. In addition, the procedure of rotordynamic analysis for dry vacuum pump rotor-bearing system was proposed and established.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.3
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• pp.83-89
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• 2000

In hydraulic control system turbine and gear motor type flowmeters are widely used to measure the flow rate under steady flow conditions. With the recent growth of interest in the measurement of instantaneous values of unsteady flow rate the test of the transient response of these flowmeters are in some significance. however an unsteady flow rate mea-surment and its calibration method with a fast response and a high accuracy have not beendeveloped. In this research particularly the dynamic characteristics of turbine and gear motor type flowmeters are investigated experimentally and simple mathematical models are proposed. The measured flow rate waveforms are compared with those by remote instan-taneous flow rate measurement method(RIFM) which has been developed by author and used for calibration As the result of frequency response test gain and phase between the measured flow rate waveforms by turbine type flowmeter and those estimated by RIFM are in good agreement up to 70Hz For the gear motor type flowmeter th simulated results by a math-ematical model proposed here agree well with the experiment nearly up to 100Hz. Also it if sound that the pressure drop across the flowmeter is increased in proportion to the frequency of the flow rate variation in a high frequency region of more than 100Hz. It can be explained that the dealy of gear motor type flowmeter in high frequency regionis mainly attributed to a first order delay consisting of the inertia of gears and internal leakage of the gear motor.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.4
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• pp.1-12
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• 2007

S45C steel has been widely used in industrial applications, such as crank shafts, gears, main spindles of machine tools, connecting rods, etc., because of its distinguished mechanical property. In the convention arc welding of S45C plates without heat treatments, it is possible for welding defects to take place, such as a void or a hot-crack, due to a high carbon composition of S45C. Laser welding process is widely used in the industrial field due to its numerous advantages: a small heat affected zone(HAZ), deep penetration, high welding speed, single-pass thick section capability, and small distortion after welding. The objective of this research works is to investigate the influence of the process parameters, such as power of laser and welding speed, on the characteristics of laser welding for the case of nickel coated and nickel uncoated S45C steel. As the result of the experiment, in case of butt welding, nickel coated S45C steel has a uniform formation of welding zone and it was judged that the welding nature was better as inner defects and the quantity of spatter were formed relatively fewer than nickel uncoated S45C steel.

• Journal of Fisheries and Marine Sciences Education
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• v.9 no.2
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• pp.121-148
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• 1997

The Japanese fishery management system has been established on the basis of various experience accumulated over many years. The fishery management system in Japan, one of the oldest fishery management systems in the world, is aimed at ensuring comprehensive utilization of the water surface and developing fishery productivity, by giving protection of the breeding environment of aquatic animals and plants, enabling the appropriate use of fishery grounds, preventing and solving disputes over fishery grounds and making other fishery adjustments. Japanese Fishery Law has been changed largely into (1) The Feudal Era(to 1900), (2) The Oldest Fishey Law(1901~48), (3) Current Fishery Law(1949 to present). Japanese fishery legislation is designed as a single package combining coastal, offshore and distant-water fisheries. During the period of the old fishery law, numerous conflicts arose over the joint use of fishing grounds and fish stocks. Such conflicts occurred among users of the same gear as well as between users of different gears or of different sizes of fishing craft. Large scale conflict sometime occurred between neighbouring fishing communities due to a lack of fairness in principle and coordination in practice. Therefore, the new fishery law enacted in 1949. This law was designed primarily to realize the most effective and rational use of fishing grounds and fishery resources, the basic philosophy being that, through democratic organization by fishermen themselves, productivity would be stimulated and incomes and living standards eventually improved. Nowadays, Community Based Fisheries Management through democratic organization by fishermen themselves have to enforce at coastal fisheries. This Community Based Fisheries Management manage to fishery resources by fishermen themselves and harvest in collaboration with that resources. Therefore, this paper is intended to briefly to describe the entire system and the historical development of Japanese fishery legislation in order to assist in reform of our country fisheries management regime.

• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.432-437
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• 2017

As 4.0 industry has been developed, research on a self-driving car technology and related parts of an automobile has been highly investigated recently. Particularly, a TAS(Torque Angle Sensor) module on steering wheel system has been considered as a key technology because of its precise angle, torque detection and high speed signal processing. The environmental assessment is generally required on the TAS module to examine high resolution of angle/torque detection. In the case of existing TAS module, angle detection errors has been occurred by back-lash on main and sub gear in addition to complicated structure caused by gears. In this paper, a structure of the TAS module, which minimizes the numbers of components and angle detection errors on the module compared with the existing TAS module, for vehicle steering system based on a Multi-track Encoder has been proposed. Also, angle detection signal processing board, and key technology of the TAS module were fabricated and evaluated. As a result of the experiments, we confirmed an excellent performance of the fabricated signal processing board for angle detection and an applicability of the fabricated angle detection board on the TAS module of vehicles by the environmental assessment an automobile standard.