• Atmosphere
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• v.25 no.2
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• pp.235-248
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• 2015

In this study, we analyzed the three dimensional variations (latitude, longitude, and height of Jet core) and wind speed of upper Jet stream in the East Asian region using recent 35 years (1979~2013) of four reanalysis data (NCEP-R2, MERRA, ERA-Interim. and JRA-55). Most of Jet core is located in $30.0{\sim}37.5^{\circ}N$ and $13.0{\sim}157.5^{\circ}E$ although there are slight differences among the four reanalysis data. The wind speed differences among reanalysis are about $3m\;s^{-1}$ regardless of seasons, the weakest in NCEP-R2 and the strongest in JRA-55. Although significance level is not high, most of reanalysis showed that the Jet core has a tendency of southward moving during spring and winter, but moving northward during summer and fall. This amplified seasonal variation of Jet core suggests that seasonal variations of weather/climate can be increased in the East Asian region. The longitude of Jet core has a tendency of systematically westward moving and decreasing of zonal variations regardless of averaging methods and reanalysis data. In general, the Jet core shows a tendency of moving south-west-ward and upward, getting intensified during spring and winter regardless of the reanalysis data. However, the Jet core shows a tendency of moving westward and downward, and getting weakened during summer. In fall, there were no distinctive trends not only in wind speed but also three dimensional locations compared to other seasons. Although the significance levels are not high and variation patterns are slightly different according to the reanalysis data, our findings are more or less different from the previous results. So, more works are needed to clarify the three dimensional variation patterns of Jet core over the East Asian region as a result of global warming.

• Journal of the Korean Society for information Management
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• v.18 no.4
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• pp.15-35
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• 2001

This paper suggests metadata as an effective search tool suitable for moving images on the web. Dublin Core, a leading metagata sceme of web resources, and MPEG-7, a coming international standard developed by MPEG, are used to construct a hybrid metadata scheme. RDF is selected as a framework for a matadata description and Moving Image Core was developed as a RDF schema. Finally, RDF/XML encoded metadata of moving images are retrieved throuth web-based database system using ASP technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.218-222
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• 2004

We developed the stamper structured mold with moving core type with nano pattern. Among the factors affecting the quality of injection molding plastic parts, We studied the effects of moving core surface heating method on the transcription of injection molding plastic parts with nano structures. Moving core surface heating has been tested by three different methods. The first was conventional injection molding process without heating moving core surface, the second was halogen lamp radiation heating process and the last was MmSH process using gas flame. As a result of making injection molded parts by using thermoplastic amorphous resins such as COC, PMMA, MmSH method which is the most high temperature of moving core surface showed the best nano pattern transcription of the three methods, but the outcome of conventional injection molding process was not better than others.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.742-744
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• 2001

Moving flat core LOA consists of iron flat core as a mover and electric magnet as a stator and operated by electromagnetic force between mover and stator. In a moving flat core type, it takes advantage of doing not have to be equipped with power supply device, having a lower manufacturing cost. But it has a lower linearity and precision. In this paper, a static characteristics of LOA were studied and analyzed using FEA. Experiments, electromagnetic force and inductance according to air gap and input currents, were carried by exciting coil. And we compared these results one another.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1787-1794
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• 2000

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.317-320
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• 2005

The LBS (Location-Based Services) are valuable information services combined the location of moving object with various contents such as map, POI (point of Interest), route and so on. The must general service of LBS is route determination service and its applicable parts are FMS (Fleet Management System), travel advisory system and mobile navigation system. The core function of route determination service is determination of optimal route from source to destination in various environments. The MODB (Moving Object Database) system, core part of LBS composition systems, is able to manage current or past location information of moving object and massive trajectory information stored in MODB is value-added data in CRM, ERP and data mining part. Also this past trajectory information can be helpful to determine optimal route. In this paper, we suggest methods to determine optimal route by querying past trajectory information in MODB system and verify the effectiveness of suggested method.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.109-119
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• 2002

In this paper, mechanism design of optical pickup actuator for fast access is proposed. This actuator is composed of moving magnet type actuator and moving coil type actuator for tracking and fine motion, respectively. Moving magnet type tracking actuator is configurated by two permanent magnets and four air-core solenoids. Additional damper by induced current in tracking actuator can reduce the transient vibration between the coarse seeking servo and fine seeking servo. Variable stiffness can be acquired by applying current to air-core solenoid simply. This actuator can achieve fast access by these additional damper and stiffness. Performance of this actuator is predicted through the FEM, simulation and simple experiment. Settling time for transient vibration is reduced to 14.7% according to simulation result.

• International Journal of Railway
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• v.6 no.4
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• pp.155-159
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• 2013

The purpose of this study was to develop a theoretical model to analyze the vibration of finite railways forced by distributed moving loads. The vibration characteristics of compliantly supported beam utilizing compressional damping model were investigated through the Rayleigh-Ritz method. The distributed moving load was analyzed as the cross correlation function on railways. This allowed the use of statistical characteristics for simulation of the moving train wheels on the rail. The results showed there is a critical velocity inducing resonant vibration of the rail. The mass spring resonance from the rail fastening systems exhibited significant influence on the resulting vibration response. In particular, the effect of the viscoelastic core damping was investigated as an efficient method for minimizing rail vibration. The decrease of the averaged vibration and rolling noise generation by the damping core was maximized at the mass-stiffness-mass resonance frequency.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.50-57
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• 2016

Refrigerator glass shelves are manufactured by Insert Injection Molding. The current process of injection of glass into the mold induces movement of the core, on urethane springs. Defects in the product can result from too low a force being transmitted from the springs. To solve this problem, the force on the moving core and the injection molding pressure were subjected to numerical analysis. Based on this, the number of urethane springs as well as their hardness was changed to improve the situation. The number of springs was changed from 6 to 4. The diameter of the springs was increased from ${\emptyset}75$ to ${\emptyset}100$, and the hardness was increased from 70 (shore A) to 90 (shore A). These improvements caused the force on the molding core to increase by approximately 65,442 N. The proportion of defects decreased by 66%.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.34-39
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• 1990

For the analysis of structures, specifically if it is large-scale, in which case it can not be solved within the core memory, the majority of computation time is consumed In the solution of simultaneous linear equation. In this study an efficient in- and out-of-core column solver for sparse symmetric matrix utilizing memory moving scheme is developed. Compare with existing blocking methods the algorithm is simple, therefore the coding and computational efficiencies are greatly enhanced. Upon available memory size, the solver automatically performs solution within the core or outside core. Analysis example shows that the proposed method efficiently solve the large structural problem on the small-memory microcomputer.