• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.3
• /
• pp.13-18
• /
• 2011

This study deals with the effect of the honing in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by honing. Therein, the honing techniques are welcomed especially as one of the physical surface improvement methods. As a result, gear honing reduces vibration and noise, and will increase the life of gear. And gear honing also changes the surface of gear tooth in a short time and price, so it is a very important method in manufacturing industry. But nowadays, it is hard to find the detail information of gear honing. The test gear is a planetary gear which is used in the automotive industry. It is manufactured by the hobbing, shaving, carburizing and honing. This study investigates the effect of honing in surface shape of SCM420H planetary gears, including fatigue strength test and characteristics of honing of SCM420H planetary gears.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.5
• /
• pp.54-59
• /
• 2012

This study dealt with effect of the grinding in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by grinding process. Therein, the grinding techniques are widely used especially as one of the physical surface improvement methods. As the results, the gear grinding process reduced vibration and noise, and increased the life of the gear. And the gear grinding improved the surface of gear tooth in a short time and low cost, thus, it is a very important process in manufacturing industry. But nowadays, it is hard to find the detail information of gear grinding process. The test piece is a planetary gear which is used in the industrial machine. The manufacture process of the test piece contains hobbing, shaving, carburizing and grinding. This study investigated the effect of the grinding process to the physiognomy and the fatigue strength of test piece which was made by SCM420H.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.3D
• /
• pp.403-412
• /
• 2011

On a curve radius, there is speed deviation because a driver who is on the curve radius can have visual distortion. The curve radius can be more dangerous than a straight radius by many reasons. Especially, visibility paralysis of delineator that is because of night and bad weather. Can pervert the information about curve sections, it threatens safety. More over accident risk is increased by influence to travel speed. Therefore, it needs to build and control delineators for driver's visibility. Therefore, this study focus on finding the two types of delineator(the retro-reflection and inside-lighting delineator) by insight-surveying and the operating speed are compared by survey and operating speed. Finally, inside-lighting delineator will be selected in terms of safety at the curve sections. The inside-lighting delineator was more effective than the retro-reflection delineator on visibility, the necessity of reduction of speed and will reduce the hazard at curve sections. Also, the study analyzes safety is guaranteed by the slight reduction of speed when the driver enters a curve radius with inside-lighting delineator. As a result, the inside-lighting delineator can give the information about horizontal and vertical profile effectively, so it can reduce the accident risk. And it can use to improve traffic safety on curve radius.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.6
• /
• pp.748-754
• /
• 2010

To reduce the computational cost required for assembling vessel fragments using surface geometry, this paper proposes a fast axis estimation method. Using circular constraint of pottery and local planar patch assumption, it finds the axis of the symmetry. First, the circular constraint on each cylinder is used. A circular symmetric pot can be thought of unions of many cylinders with different radii. It selects one arbitrary point on the pot fragment surface and searches a path where a circumference exists on that point. The variance of curvature will be calculated along the path and the path with the minimum variance will be selected. The symmetric axis will pass through the center of that circle. Second, the planar patch assumption and profile curve is used. The surface of fragment is divided into small patches and each patch is assumed as plane. The surface normal of each patch will intersects the axis in 3D space since each planar patch faces the center of the pot. A histogram method and minimization of the profile curve error are utilized to find the probability distribution of the axis location. Experimental results demonstrate the improvement in speed and robustness of the algorithms.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1997-1998
• /
• 2008

Pulse diagnosis is the one of the most important diagnostic process to traditional medical doctors. Although the pulse diagnosis position, Gwan is apart from Chon or Cheok by 10$\sim$20mm at most, traditional medical doctors applies different indent pressures and even they states different pulse images are felt at Chon, Gwan and Cheok. One the other hand, the education on pulse diagnosis behavior includes tantalizing problem caused by no tool for communication between trainer and trainee. On account of this situation, we tried to develop a system which can measure the hold-down pressure during a pulse diagnosis and compare the hold-down pressure profile of trainer and that of trainee. This system can be divided into three parts - pulse pressure sensing part, signal acquisition part and data storing part. A correction curve was generated by the relation between output voltages and standard weights. Using this system, 3 channel hold-down pressure profile of a oriental medical doctor were recorded three times. In the profile, three period were observed and all period included two process for searching the depth of pulsation and for classifying the pulse feeling into one or more of 28 pulse types. The maximum value of pulse profile was 1.3$kg{\cdot}f$ which was more than reported by previous chinese groups and the mean values of three channel ranged from 240$g{\cdot}f$ to 430$g{\cdot}f$. In frequency domain, each channel has some dominant frequency components - about 10Hz, 35Hz and 75Hz. In further study, we want to collect more profiles from lage number of oriental medicine doctors and hope to develop a measuring system which can measure the hold-down pressure on subject's skin directly.

• Journal of Korea Water Resources Association
• /
• v.52 no.1
• /
• pp.83-96
• /
• 2019

In order to properly manage the river water use, it is necessary to collect reliable data of river water use. However, It is not easy to get credible river water use data in Korea because there are some difficultites in reporting and measuring river water use data. Thus, Han River Flood Control Office has installed and operated measuring facility using V-ADCP on the EOUBO intake open channel in the Gosan-Bongdong station section of the Mankyung river, where the use of agricultural water is large. In this study, the applicability of the V-ADCP velocity profile method was evaluated for real-time river water use. For this reason, the parameter sensitivity of Chiu's 2D velocity distribution equation was analyzed and the optimal parameters based on actual discharge data were calculated. In addition, the characteristics of the velocity profile method were analyzed by comparative evaluation of the rating curve method and the index velocity method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.6
• /
• pp.1743-1752
• /
• 1996

In this paper, a precision inspection technique using CAD/CAI integration is proposed for the parts having very thin and sharp 3 dimensional curve features. The technique begings with feature reconstruction of turbine blades which have 3 dimensional combined feometry, such as splines, and thin circles. The alifnment procedures consistsb of two phases-rough and fine phases : rough phase alignment is based on the conventional 6 point5s probing on the clear cut surfacef, and fine phase alignment is based on the intial measurement on the 3 dimensional curved parts using an lterative measurement feed-back least sequares technique for alignment. Forf the analysis of profile tolerance of parts, the actual measured points are obtained by finding the closet points on the CAD geometry by the developed subdivision technique and the Tschebycheff norm is applied based on iterative fashion, giving accurate profile tolerance value. The developed inspection technique is applied to practical procedures of blade manufacturing and demonstrated high performance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.7
• /
• pp.995-999
• /
• 2004

Fabrea salina is a hypersaline ciliate having importance as a live food source for juvenile stages of aquatic animals including smaller invertebrates. The analysis of this ciliate for proximate and biochemical composition was carried out. The moisture, protein, fat, carbohydrate and ash content of F. salina from natural sources were 86.66$\pm$0.380, 56.66$\pm$0.494%, 36.66$\pm$0.614%, 1$\pm$0.073% and 4$\pm$0.182%, respectively. Gas chromatographic analysis (percent area below the curve) revealed that the presence of oleic acid was higher over other fatty acids in both natural and cultured F. salina. The absolute content of oleic acid was higher in natural (18.91% area) than in the cultured (10.74% area) F. salina. Linoleic and linolenic acids were also among major fatty acids with the percentage area of 16.29 and 14.58, respectively. The number of fatty acids in cultured Fabrea was less as compared to the natural ones and the oleic acid was followed by palmitic acid, palmitoleic acid, linoleic acid and stearic acid.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.2
• /
• pp.102-112
• /
• 1997

This paper describes the method that can construct kinematically admissible velocity fields for forging of gear-like components which have tooth shape around the cylinder. The kinematically admissible velo- city fields for the various gear-like components, involute spur gear, trapezoidal spline, square spline, ser- ration and trochoidal gear, were constructed by pilling up the velocity components according to the shape of tooth and billet. The billets, of hollow and solid, were Al 2218 and 2024. To verify the method, the analyses and experiments were carried out and compared with each other. For analyses, the half pitches of com- ponents were divided into several deformation regions based on their tooth profile. A neutral surface was used to represent the inner flow of material during forging. Its location varied with the energy optimazation and its contour varied with the number of teeth. In experiment, the contour of material filling up the tooth zone is hyperbolic curve caused by the frictional drag on the interface of die-wall/workpiece but, in the analysis, it is an arc which retains the same contour during all forging operation.

• Journal of Astronomy and Space Sciences
• /
• v.20 no.1
• /
• pp.63-82
• /
• 2003

Using the Schwarzschild's linear programming technique, we obtained the general solutions of the collisionless Bolzmann equation describing the spherical galaxy in dynamical equilibrium. From this calculation we have confirmed the existence of isotropic spherical galaxies obeying a de Vaucouleurs'law which includes a dark halo. The flattening profile of the velocity dispersion curve seen in the elliptical galaxies can be explained as the increase of mass to light ratio in this dark matter. The space density distribution of this dark matter shows that the core radius of the dark matter is smaller than the effective radius of the galaxy.