• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.95-102
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• 2005

USGA green specification is currently accepted in construction method of Korea. This study was carried out to find the factors influencing growth of turfgrass associated with soil physical properties of soil root-zone on golf green constructed with USGA method. Three putting greens in poor turfgrass and one in good turfgrass condition were selected for investigation on one golf course site at mid-South Korean peninsula. Soil hardness, moisture content, root length, and turf density were measured on-site greens, and soil physical properties and soil chemical properties also analyzed in laboratory. As a result of on-site surveys and soil physical tests in laboratory, soil physical properties were most important factors which influenced on turfgrass growth at tested greens. The results of soil particle analysis on green No. 2, in good turf condition, matched USGA sand particle recommendations. But those greens such as Nos. 1, 11 and 16, in poor putting greens, showed high soil compaction and improper soil particle distribution. Those factors created low leaf density, poor root depth, and higher moisture content compared with lower part of topsoil. Such phenomena caused inadequate turfgrass growth with soil hardening associated with poor drainage. Therefore, declines of soil physical properties associated with improper particle distribution caused a major factor influencing on turfgrass growth in golf green. Adequate test of soil particle analysis by USGA specification and proper construction method followed by adequate turf maintenance should be performed to obtain optimal turf quality on putting green.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.998-1001
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• 2002

Saltwort (Salicornia herbacea L.), a kind of halophytes in Japan, is under investigation as a feed source for livestock as well as potential oilseed crop in salt marshes and salt fields. The present experiment was undertaken to analyze the nutritive value of saltwort as feed for ruminants. To determine the apparent digestibility and nutritive value of saltwort, five Japanese native goats were fed the diets consisting of alfalfa hay cubes with 15 or 20% (n=3 and n=2, respectively) inclusion levels of saltwort in the total diet on a DM basis. All the animals were randomly offered alfalfa hay cubes as a base diet or a mixed diet of alfalfa hay cubes and saltwort at maintenance level, thereafter, alternative feed (a base or mixed diet) was offered to the experimental animals (the incomplete crossover design). Analysis of the chemical composition of saltwort showed that the plant contained high levels of total ash (40.2% DM), sodium (12.7% DM) and chlorine (19.7% DM), and relatively high levels of CP (11.7% DM) and NDF (40.4% DM). Contents of TDN and digestible CP (DCP), DE and ME of saltwort were 33.5% DM, 8.4% DM, 7.4MJ/DM kg and 5.0MJ/DM kg, respectively. These results indicate that saltwort is rich in DCP and minerals (mainly sodium chloride), but poor in energy, suggesting that saltwort could be used as a mineral or CP supplement for ruminants raised around salinized areas in which high quality feed may not be available.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.340-345
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• 2008

Oxidative stress is one of the major causes of failure of in vitro storage of boar semen. Reactive oxygen species (ROS) are one of the important mediators of oxidative stress during in vitro storage of boar semen. Our study examined the effects of taurine on sperm characteristic and on in vitro developmental embryos during in vitro storage of boar semen for 7 days. Semen was randomly aliquoted into 3 centrifuge tubes and treated with different concentrations of taurine (25-100 mM). The characteristics of boar sperm were analyzed for motility by light microscopy, viability by using a Makler counting chamber and membrane integrity by a hypoosmotic swelling test (HOST). The percentages of motile spermatozoa in taurine groups after 5 days were significantly higher compared to the control. Sperm viability in the control was lower than in taurine groups after 7 days irrespective of different taurine concentration. In the hyoosmotic swelling test (HOST), significantly higher results were obtained in taurine groups after 3 days. Also, the developmental rates of IVM/IVF porcine embryos from semen treated with pyruvate and taurine were significantly increased when compared with the control (p<0.05). These results indicate that supplementation of taurine as an antioxidant in boar semen extender can improve the semen quality.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.3
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• pp.251-259
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• 2004

The prediction accuracy of prestress plays an important role in the quality of maintenance and the decision on rehabilitation of infrastructure such as prestressed concrete bridges. In this paper, the Bayesian statistical method that uses in-situ measurement data for reducing the uncertainties or updating long-term prediction of prestress is presented. For Bayesian analysis, prior probability distribution is developed to represent the uncertainties of creep and shrinkage of concrete and likelihood function is derived and used with data acquired in site. Posterior probability distribution is then obtained by combining prior distribution and likelihood function. The numerical results of this study indicate that more accurate long-term prediction of prestress forces due to creep and shrink age is possible.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.46-52
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• 2006

For ships, heat resistant coating is applied on the aluminized steel pipe systems dealing with high temperature steam over $200^{\circ}C$. The coatings on these steam pipes should retain both heat resistance and anti-corrosion properties to provide long-term resistance against coating defects (rust, delamination and crack) under the harsh outdoor environment including repeated seawater wetting and condensation. Thus, it is important to improve the coating qualities and to reduce maintenance works for these steam pipe systems. In this study, five different commercial heat resistant coatings (A, B, C, D, E) were selected for evaluation. Various physical properties of these coatings were evaluated on the coatings applied on the aluminized steam pipes. FT-IR analysis was also employed to identify the factors contributing the degree of heat resistance and durability of each coating material. The results indicated that the heat resistance capacity of coatings increased with the increase of silicon content as well as the decrease of substituent content. Both products C and D showed the best coating qualifies, which can be standard coating systems for future steam pipe areas.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.229-239
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• 2011

This study aims to suggest profitability models of local cultural festival to be a focal point of local culture to overcome the abuses as an annual event led by the local government agencies have been in force in every local areas currently, to elicit the local residents' voluntary participation and to engage the outside tourists in connection of a more effective promotion and marketing. The festival is attractive to people with that provoke mirth and inspire curiosity, but the festival is not a one-time event ongoing maintenance enlarge: It is absolutely necessary in order to effort to reach at consumer-oriented quality of service. Also this research intends to present a activation scheme by developing profitability models to make profits while holding a number of risks taking into account the characteristics of the local festival service carried out. To this end, based on established research, leading indicator and expert opinion were analyzed through multiple regression analysis.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.623-628
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• 2007

Metro Subway System is widely known as the leader of public transportation in a metropolitan area. The signal interlocking is one of the most important organs that plays a major role in the system. By improving the quality of signal interlocking on of the traffic system and keeping its maintenance on a high level will not only repair the current state, but it will also let the PLC(Programmable Logic Controller). The Non-Vital relay of No. 3, 4 Line are the most one of the unstable system, device, which underwent a process of fine manufacture establishment and a close examination, obtained as a new device. Utilizing the equipment with cautious preservation on the system will enhance the current state of the signal device. Especially, the test for improvement and development based upon the technique that decreases the frequency of defect produced will further precipitate its efficiency. With authorization of imposing the newly made equipment will bring improvement to the signal technology and to the industry at largest extent.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1303-1308
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• 2007

Recently, precast concrete tracks are replacing ballast track for efficient and economic maintenance of track. Precast concrete railroad tracks are manufactured in factory, and transported to railroad construction site for installation. Therefore, quality of precast concrete track itself should be sufficiently good. On the contrary to the convenient manufacturing of precast concrete track, the installation of a precast concrete track requires careful steps. Typically, a precast concrete track is placed on an approximately 15-cm thick lean concrete layer. A mortar is filled between lean concrete layer and precast concrete track to adjust the sloping angle of a precast concrete track for a safe train operation at a curvy section. Then, the use of filled mortarproduces a void underneath a precast concrete track, which is harmful to structural safety of a precast concrete track undercyclic loading. Therefore, it is essential to make sure that there is no void left beneath a precast concrete track after mortar filling. In the continuous resonance method, the amplitude of frequency response measured using an instrumented hammer and an accelerometer is plotted against a pseudo-depth, which is half of the wave velocity divided by frequency. The frequency response functions are measured at consecutive measurement locations, 6-cm interval between measurement points, and then combined together to generate a 2-D plot of frequency response. The sections with strong reflections or large amplitude of frequency response are suspicious areas with internal voids and unfilled areas. The 2-D frequency response plot was efficient in locating problematic sections just by examining the color shade of a visualized plot in 2-D format. Some of the problematic sections were drilled to make a visual inspection of mortar filling. The visual image of interface between mortar and precast concrete track was verified using the validity of the continuous resonance technique adopted in this research.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.53-59
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• 2011

In recent years, mobile communication service is used extensively as a larger service area for the maintenance of quality of service required by the expansion of service areas and As the ever-increasing role in relays, and the location is relatively easy to install and less constrained costs, operating cost savings in terms of ICS(Interference Cancellation System) repeaters are required. However, an adaptive algorithm that is applied when updating the filter due to the increase in volume of operations increase the complexity of hardware implementation is fraught with many difficulties. In this paper, if there is a path that feedback. ICS repeater utilizing baseband signal processing for the removal of interfering signals from the feedback operation, significantly reducing the amount of reducing hardware complexity Complex Singed Signed LMS adaption algorithm is proposed. Proposed algorithm for evaluating the performance of Static channel WCDMA signal environment for the ICS, the results of the simulation algorithm, convergence speed and better performance in therms of convergence errors that are required through the implementation of the operation greatly reduces the amount of hardware complexity able to reduce the effect was visible.

• Journal of IKEEE
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• v.22 no.3
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• pp.733-737
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• 2018

In this paper, we describe the effects on the power system by adding renewable generator. In order to examine the stability of the system, the system analysis was performed using the PSS/E software. We confirmed whether occur the line overload of system through the load flow analysis and contingency analysis. and confirmed whether exceed of fault current using the fault current analysis. Dynamic stability of the system is analyzed through dynamic simulation. The analysis of the system according to the addition of the renewable generator was carried out according to the power system reliability and electricity quality maintenance standard.