• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.185-190
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• 2005

The shot peening process is often used to improve fatigue properties of metal parts. Among them, It is the most use in an auto-component. In order to achieve optimum, repeatable and reliable fatigue enhancement from the shot peening process, the important shot peening parameters must be controlled. In this paper, the optimum peening intensity (Almen intensity) condition is investigated by experiment. The Spur Gear steel was used to investigate shot peening effects. The fatigue life at $\sigma_a=1,050$ and $\sigma_a=1,250MPa$ first gently increases, then drops gently as peening intensity increases compared with unpeened specimen. Experimental results show that the optimum peening intensity range is $0.391\~0.434mmA$..So the fatigue strength and fatigue life have been tremendously increased by optimum-peening treatment. However, the fatigue strength and fatigue life have been decreased by over peeing.

• Korean Journal of Plant Taxonomy
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• v.39 no.4
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• pp.296-298
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• 2009

Cephalanthera erecta var. oblanceolata N. Pearce & P. J. Cribb (Orchidaceae), previously known only from Bhutan, was first recorded in the lowland of Gyeonggi-do, Whaseong-shi, Seosin-myeon. This taxon is distinguished from Cephalanthera erecta by characteristics such as oblanceolate dorsal sepal and lateral petals, lanceolate lateral sepals, and simple, oblanceolate lip without spur. The vernacular name was newly given as 'Min-eun-nan-cho', based on the lip without spur. The morphological characteristics and illustrations of the taxon are provided along with its photograph.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.102-112
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• 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 Veterinary Clinics
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• v.37 no.1
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• pp.46-49
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• 2020

Flexor enthesopathy is an important cause of elbow lameness in dogs. Flexor enthesopathy is divided into primary and concomitant forms deciding the treatment. The imaging characteristics in affected dogs are irregular medial humeral epicondyles, spur, calcified bodies adjacent to medial humeral epicondyle, thickened and contrast enhancement of the affected muscles. In this report, the radiography, computed tomography (CT), and magnetic resonance imaging (MRI) were performed for right forelimb lameness of a 3-year-old dog. The irregular sclerotic changes and spur of the medial humeral epicondyles were shown with calcified bodies on radiography. Thickened flexor muscles in right forelimb and fragmented coronoid processes of both elbows were observed on CT. On MRI, high signal intensity of the bilaterally thickened flexor muscles with contrast enhancement was detected. Based on these results, concomitant flexor enthesopathy with fragmented medial coronoid process of bilateral elbows was diagnosed in this dog.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.6
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• pp.1-7
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• 2022

This work investigated the performance improvement of a medium-pressure fixed-displacement-type SPUR gear pump, which is mainly used in the machine tool industry. The 3D CFX analysis and IS technique were applied using ANSYS (commercial FEM code) and compared with experimental results to ensure the reliability of the analysis. In addition, the performance improvement of the pump was obtained using the theoretical volumetric displacement equation, and the gear tooth width was changed. The pressure flow performance curves were compared, and the results were analyzed according to the width of the gear teeth. This is a factor that can cause irregular flow, vibration, and noise inside the gear pump owing to friction between the housing and gear pump.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.5
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• pp.95-103
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• 1996

This paper describes a computer aided design system for spur and helical gears. To establish the appropriate program, an integrate approach based on a rule-base system was adopted. This system is implemented on the personal computer and its environment is a commercial CAD package called AutoCAD. This system includes a main program and five sub-modules such as data input module, tooth profile drawing module, strength calculation module, and drawing edit module. In the main program, all the sub-modules are loaded and the type of gear and tooth profile are selected. In the data input module, the variables which are necessary to the design of gear are selected from the database. In the drawing module, from the calculated results, the required gear tooth is produced on the screen. The developed system that aids gear designer provides powerful capabilities for gear design.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.165-170
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• 1996

The study was carried out to identify the characteristics of leafy shapes, and to establish the cultural practices such as shading condition, fertilization method, and planting distance of Cirsium nipponicum. Leaf shapes in this plant consist of two kinds, lobation and non-lobation which has two spur type showing large and small spur. Protein band patterns showed that a new protein band in non-lobation with large spur was appeared at the 116.4kDa. For shading condition and fertilization method, number of stems in non-shading and organic matter treatment was higher than that of shading 55% with 3.7. Fresh leaf yield on non-shading and organic matter treatment was higher than that of other treatments. Growth characteristics of leaf number was increased in the $60\times30cm$ treatment, but was redeuced to some extent compared with $60\times45cm$. To increase the fresh leaf yield, the optimum planting distance was $30\times20cm$ with 4,100kg/10a.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.507-520
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• 2003

A V-shaped riffle is an artificial hydraulic structure haying two wings from the streamside with a narrow opening in between. It is usually made of crushed stones or large boulders. It limits channel width and accelerates the flow through the constricted section causing a local scour just downstream. The V-shaped riffle provides with a unique aquatic habitat by forming a pool and sandbars around the pool edge, increasing local morphologic, hydraulic and sedimentological diversity. This study investigates experimentally the scour characteristics of the V-shaped riffle in the sandbed stream and proposes a predictive equation for the scour. Total 45 cases of experiments were conducted to examine the effect of hydraulic factors and configuration of V-shaped riffle on the geometry of scour holes. From the comparison of the experimental results of this study with the predictive equation of spur dike by Breusers and Raudkivi(1991), it is found that their predictive equation of spur dike underestimates the maximum scour depth downstream of the V-shaped riffle. h new predictive equation for the maximum scour depth was developed using the non-dimensional hydraulic and geometrical variables. The parameters used in the proposed equations were determined using the experimental data. The analysis reveals that the scour depth is dependent dominantly on the Froude number at the opening of the V-shaped riffle, while the angle of riffle and the opening width also affect the scour depth. The proposed equation for the scour of V-shaped riffle well agrees with the experimental data. It can be used for estimating the scour of the V-shaped riffle in sandbed streams.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.115-121
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• 2016

This study was conducted to provide the basic policy information for establishing efficient forest-road networks. Synthetic forest-road networks that consist of main and spur roads and forest-road networks with only main road (hereafter called "main-road network") were planned for the five forest-road experimental districts of Korea Forest Service in this study. Road density of the synthetic forest-road networks was calculated and compared with the road density of the main-road networks. The results showed that the optimum road density of the synthetic forest-road networks was 10.1~15.9 m/ha, and the road density of the main-road networks was 8.4~12.4 m/ha. The construction cost of the synthetic forest-road networks was estimated about 1~8% lower than the main-road networks, while the road density was 20~30% greater than the main-road networks. As timber volume and hauling cost increased, the optimum road density of the synthetic forest-road networks increased, within which the road density of highstandard main road rapidly increased. On the other hand, the spur road density increased with slope gradient.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.7
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• pp.485-491
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• 2011

This study was performed to investigate the characteristics of nutrient removal of municipal wastewater in membrane bioreactor system. Membrane bioreactor consists of four reactors such as two intermittently anaerobic tanks, the oxic tank and the sludge solubilizaion tank with an internal recycle. The hydraulic retention time (HRT) and flux were 6.5 hours and $20.4L/m^2{\cdot}hr$ (LMH), respectively. The removal efficiency of $COD_{Cr}$, SS, TN and TP were 94.0%, 99.3%, 99.9%, 69.9%, and 66.9%, respectively. The estimated true biomass yield, specific denitrification rate (SDNR), specific nitrification rate (SNR), specific phosphorus release rate (SPRR) and specific phosphorus uptake rate (SPUR) were 0.34 kgVSS/kgBOD d, $0.067mgNO_3-N/mgVSS{\cdot}d$, $0.028mgNH_4-N/mgVSS{\cdot}d$, 16.0 mgP/gVSS d and 2.1 mgP/gVSS d, respectively. The contents of nitrogen and phosphorus of biomass were 8.9% and 3.5% on an average.