• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.73-77
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• 2016

In this study, we examined the changes of fruit number and fruit weight according to the length of bearing branch of Actinidia arguta and identified the correlation the length of bearing branch and fruit characteristics. The fruit weight and the fruit number of A. arguta bearing branch which length are below 15 cm and over 30 cm were 11.7 g, 4.3 and 12.3 g, 13.8, respectively. From the results, the bearing brach which length was below 15 cm must be removed in winter season pruning. The pruning experiment was conducted to examine the effects on fruit quality and yield of A. arguta. Total fruit yield of heavy-pruning was $14.3{\pm}1.5kg/tree$. The production of fruits over 15 g wight was $8.2{\pm}0.9kg/tree$, that of fruits between 10 g to 15 g was $4.0{\pm}0.7kg/tree$, and that of fruit below 10 g was $2.1{\pm}0.3kg/tree$, respectively. Average fruit yield of nonpruning was $26.7{\pm}2.1kg/tree$, fruit yield over 15 g, between 10 g and 15 g, and below 10 g were $2.5{\pm}0.5kg/tree$, $19.2{\pm}1.4kg/tree$, and $5.0{\pm}0.6kg/tree$, respectively. Distribution of high quality fruit (over 15 g) showed that non-pruning was almost 15~16 g but pruning was evenly distributed between 15 g and 20 g. According to the survey, The high quality fruit (over 15 g) would not be harvested if the winter pruning is not applied in the A. arguta cultivation.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.381-386
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• 2017

'Jangha' is a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2014. The 'Jangha' cultivar originated in 2008 from a cross between 'Goha' and 'Elsinore' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solids contents under long-day and high temperature conditions. This cultivar was initially named 'Saebong No. 6' after examining its characteristics and productivity in summer culture from 2010 to 2012. After two regional adaptability tests in 2013-2014, 'Jangha' was selected from Saebong No. 6 as an elite cultivar. The general characteristics of 'Jangha' include semi-spreading type, elliptical leaves, and moderately vigorous growth. The fruit are conical in shape, and red in color. 'Jangha' plants have 21.4 leaves, 55.8 fewer than 'Flamenco' plants. The soluble-solids content of 'Jangha' was 8.9%, which was 1.2% higher than that of 'Flamenco'. The average fruit weight of 'Jangha' was about 11.7g and the marketable yield was $19,013kg{\cdot}ha^{-1}$, 141% higher than 'Flamenco'. 'Jangha' is suitable for summer season cultivation as a high soluble solids contents cultivar, because it shows continuous flowering habit under long-day and high temperature conditions.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.739-743
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• 2014

This work characterizes 'Yeolha', a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar that was released by the Highland Agriculture Research Center, RDA, in 2013. This cultivar originated from a 2008 cross between 'Goha' and 'Elsinyo' and showed excellent ever-bearing characteristics including continuous a flowering habit under long-day and high temperature conditions. It was originally named 'Saebong No. 5' after examining its characteristics and productivity in summer culture from 2010 to 2013. After two regional adaptability tests in 2012, it was selected as an elite cultivar and renamed 'Yeolha'. The general characteristics of 'Yeolha' include a semi-spreading plant type, elliptic leaves, and strong vigor in growth. Its fruit is conical and red. T he s oluble s olids content of 'Yeolha' is 8 .6%, w hich is 0.6% h ig her than t hat of 'Flamenco', b ut f ruit hardness is lower than that of 'Flamenco'. The average fruit weight of 'Yeolha' is about 12.1 g and the marketable yield is $28,133kg{\cdot}ha^{-1}$, which is 117% higher than that of 'Flamenco'. 'Yeolha' is resistant against Fusarium wilt. In addition, 'Yeolha' is suitable for four-season cultivation as a high harvesting cultivar because it shows continuous flowering under long-day and high temperature conditions.

• Journal of the Korean GEO-environmental Society
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• v.7 no.6
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• pp.101-111
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• 2006

In case of drilled shafts installed by drilling through soft overburden onto a strong rock, the piles can be regarded as end-bearing elements and their working load is determined by the safe working stress on the pile shaft at the point of minimum cross-section or by code of practice requirements. Drilled shafts drilled down for some depth into weak or weathered rocks and terminated within these rocks act partly as friction and partly as end-bearing piles. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft pile performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. In this study, the numerical analyses are carried out to investigate the behavior characteristics of side of rock socketed drilled shafts varying the loading condition at the pile head. The difference of behavior characteristics of side resistance is also evaluated with the effects of modelling of asperity.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.324-333
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• 1997

The research has been made for the effects of the pollution by the abandoned coal mine drainage on the physical and chemical properties of soil, stream sediment and soil water. The soils overspreaded by the abandoned coal don't develop solum and the bulk density is $1.83g/m^3$, compared with $1.14-1.38g/m^3$ in the other forest soils. The soil pH range in coal bearing region ie, from 4.01 to 4.11 and non-coal bearing soil range is from 5.03 to 5.13. Heavy metals such as As, Cr, Ni, Mo and Ba of coal bearing soils and polluted stream sediments have larger concentration than those of non-coal content and non-polluted. Especially As and Mo concentrations are largely high in coal bearing. The relative ratios $K_2O/Na_2O$ of geochemical elements are higher in coal bearing soil and polluted stream sediments than those of non-coal bearing soils and non-polluted stream sediments as well as black shales of the Changri Formation. However, $MgO+Fe_2O_3+TiO_2/CaO+K_2O$ are the opposite trends, so that the ratios are lower in the polluted regions. The soil water pHs in the polluted regions are the strong acid(pH3.4-4.2) and buffer capacity of the polluted soil is low because canons such as $Na^+$, $K^+$, $Mg^{+2}$are leached by the acidification.

• Geomechanics and Engineering
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• v.16 no.4
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• pp.449-461
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• 2018

The load sharing ratio (${\alpha}_{pr}$) of piles is one of the most common problems in the preliminary design of piled raft foundations. A series of 3D numerical analysis are conducted so that special attentions are given to load sharing characteristics under varying conditions, such as pile configuration, pile diameter, pile length, raft thickness, and settlement level. Based on the 3D FE analysis, influencing factors on load sharing behavior of piled raft are investigated. As a result, it is shown that the load sharing ratio of piled raft decreases with increasing settlement level. The load sharing ratio is not only highly dependent on the system geometries of the foundation but also on the settlement level. Based on the results of parametric studies, the load sharing ratio is proposed as a function of the various influencing factors. In addition, the parametric analyses suggest that the load sharing ratios to minimize the differential settlement of piled raft are ranging from 15 to 48% for friction pile and from 15 to 54% for end-bearing pile. The recommendations can provide a basis for an optimum design that would be applicable to piled rafts taking into account the load sharing characteristics.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.416-423
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• 2004

This paper presents the thermal characteristic analysis of a high-speed horizontal machining center with spindle speed of 50,000rpm and feedrate of 120m/fin. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motors and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guides. The thermal characteristics such as the temperature distribution, temperature rise, thermal deformation and step response, are estimated based on the finite element model of machining center and the heat generation rates of heat sources related to the machine operation conditions. Especially, the thermal time constant assessed from the step response function is introduced as an index of thermal response characteristics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.764-769
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• 2007

This paper is studied the noise and vibration characteristics analysis of the three-phase induction AC motor of the electrical forklift. And we suggest the method which the reduction orders the noise and vibration to be the mechanical. In other to investigate these characteristics, we considered the mechanical characteristics, the electromagnetic effects, and these interactions. In mechanical, we studied the characteristic of the stator, the bearing supported condition of the rotor, and the sound radiation. In electronically, this paper is considered the harmonic effect which is related the magnetic motive force (mmf) with respect to the characteristic of the slot number of the rotor and the stator and the pole number of the motor. Finally we investigated the overall noise and vibration of the induction motor by relations between the electronically harmonic and the mechanical resonance of the stator. By the analysis of the generally three-phase induction motor, we suggest the design methodology to low noise and vibration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.90-95
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• 2005

To perform the finish outside-diameter grinding process of ferrules which are widely used as fiber optic connectors, a high-precision centerless grinding machine is necessary. In this study, the thermal characteristics of the high-precision centerless grinding machine such as the temperature distribution, temperature rise and thermal deformation, are estimated based on the virtual prototype of the grinding machine and the heat generation rates of heat sources related to the machine operation conditions. The reliability of the predicted results is demonstrated by the temperature characteristics measured from the physical prototype. Especially, the predicted and measured results show the fact that the high-precision centerless grinding machine consisted of the hydrostatic GW and RW spindle systems, hydrostatic RW feeding mechanism, RW swivel mechanism, on-machine GW and RW dressers, and concrete-filled steel bed, has very stable thermal characteristics.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.137-142
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• 2002

The fluid mechanics and operating conditions of gas-lubricated proceeding bearings in micro rotating machinery such as micro polarization modulator and micro gas turbine are different from their larger size ones. Due to non-continuum effects, there is a slip of gas at the walls. Thus in this paper, the slip flow effect is considered to estimate the pressure distribution and load-carrying capacity of micro gas-lubricated proceeding bearings as the local Knudsen number at the minimum film thickness is greater than 0.01. Based on the compressible Reynolds equation with slip flow, the static characteristics of micro gas-lubricated proceeding bearings are obtained. Numerical predictions compare the pressure distribution and load capacity considering slip flow with the performance of micro proceeding bearings without slip f]ow for a range of bearing numbers and eccentricities. The results clearly show that the slip flow effect on the static characteristics is considerable and becomes more significant as temperature increases.