• Journal of Auto-vehicle Safety Association
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• v.15 no.4
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• pp.71-78
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• 2023

This study presents the direction of data triggers and elements to be recorded in automated vehicles in the future in relation to the event data recorder (EDR) and data storage system for automated driving (DSSAD). It does not distinguish between the EDR and DSSAD, but suggests data triggers and elements in preparation for overall automated vehicle accidents and dangerous situations. To propose, the current status of discussions on EDR/DSSAD internationally and the case of investigating accidents with automated vehicles under temporary driving licenses in Korea were analyzed. Based on the analysis, the direction of data triggers and elements of the EDR/DSSAD of automated vehicles were presented.

• Journal of the Korea Furniture Society
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• v.28 no.1
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• pp.47-52
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• 2017

With the rapid economical and technological progress in China, the demand for wine increased tremendously along with the need for wine storage furniture and wine related products. Although demand for furniture increased, consumers' emotional need toward high quality design product has not been met properly. As the quality of people's life improves, they pursue better materials providing them with higher mental satisfaction. To meet the specific demand of Chinese market stated above, the direction of this report is set as to study pattern elements of Chinese traditional lattice and combine them with wine storage furniture design and crafting, which is originated from western culture. By doing that, the study is aimed to suggest a new direction of Chinese modern design and to improve the fundamental notion of Chinese furniture design. Although wine and wine racks are from western world, the wine mini-bar designed in this study stands out for its beauty and taste of eastern culture. It not only fits perfectly to the habits and taste of wine lovers, but also goes very well with fusion style interior design trend in modern China. The furniture carries the charm of eastern cultural tradition and elegance of modern furniture design in one.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2989-2994
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• 2007

Gas hydrates are ice-like crystalline compounds that form under low temperature and elevated pressure conditions. Although hydrate formation can pose serious flow-assurance problems in the gas pipelines or facilities, gas hydrates present a novel means for natural gas storage and transportation with potential applications in a wide variety of areas. An important property of hydrates that makes them attractive for use in gas storage and transportation is their very high gas-to-solid ratio. In addition to the high gas content, gas hydrates are remarkably stable. The main barrier to development of gas hydrate technology is the lack of an effective method to mass produce gas hydrate in solid form. The first objective of this study is investigating the characteristics of gas hydrate formation related to several factors such as pressure, temperature, water-to-storage volume ratio, concentration of SDS, heat transfer and whether stirred or not respectively. And the second objective is clarifying the relation between the formation efficiency and each factor in order to find the proper way or direction to improve the formation performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.848-851
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• 2007

Recently, as the demand of the information storage devices with large storage capacity such as BD(Blu-ray Disk) and HDTV(high-definition television) is increased, the optical storage devices are also required to have fast data transfer rate and large storage capacity. To satisfy these requirements, the actuator for optical disk drive should have high flexible mode frequencies for system stability. In this paper, we suggested a moving magnet type actuator having high flexible mode frequency. However, the moving magnet type actuator does not have sufficient driving sensitivities due to the weight of its moving part. To improve driving sensitivities, we designed the model with the closed electromagnetic circuit for tracking direction. In addition, driving sensitivities and flexible mode frequencies were improved by using DOE(Design of Experiments) for magnetic circuit and modifying the lens holder. Consequently, it is confirmed that the designed model is satisfied with the desired specifications.

• Carbon letters
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• v.11 no.4
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• pp.285-292
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• 2010

Novel unsaturated polyester composites with PAN-based nanofiber, stabilized PAN nanofiber, and carbonized nanofiber webs have been fabricated, respectively, and the effects of the nanofiber web content on their electrical resistivity, the thermal stability, dynamic storage modulus, and fracture surfaces were studied. The result demonstrated that the introduction of just one single layer (which is corresponding to 2 wt.%) of the carbonized nanofiber web to unsaturated polyester resin (UPE) could contribute to reducing markedly the electrical resistivity of the resin reflecting the percolation threshold, to improving the storage modulus, and to increasing the thermal stability above $350^{\circ}C$. The effect on decreasing the resistivity and increasing the modulus was the greatest at the carbonized PAN nanofiber web content of 8 wt.%, particularly showing that the storage modulus was increased about 257~283% in the measuring temperature range of $-25^{\circ}C$ to $50^{\circ}C$. The result also exhibited that the carbonized PAN nanofibers were distributed uniformly and compactly in the unsaturated polyester, connecting the matrix three-dimensionally through the thickness direction of each specimen. It seemed that such the fiber distribution played a role in reducing the electrical resistivity as well as in improving the dynamic storage modulus.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.6
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• pp.11-16
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• 2017

Multi-level holographic data storage requires modulation codes for avoiding two dimensional inter-symbol interference (2D-ISI). Modulation codes can remove the fatal ISI pattern of neighboring the largest and the smallest symbols. In this paper, we propose a 4-level 4/6 modulation code and its trellis encoding for error correction. The proposed 4/6 modulation code prevents that the symbol 0 and 3 are not adjacent in any direction. Also, we compare the proposed modulation code with the same code rate modulation codes for four-level holographic data storage.

• Journal of Power Electronics
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• v.15 no.4
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• pp.1026-1034
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• 2015

In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

• Journal of the Korean Institute of Gas
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• v.27 no.2
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• pp.95-103
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• 2023

In this paper, in order to evaluate the deformation characteristics of the hydrogen gas storage vessel(Type 1) when considering gas pressure, the VMS generated in the hydrogen gas storage vessel according to the notch shape of ISO 18119 was interpreted as a FEM(Finite Element Method). According to the analysis results, the maximum VMS generated in the longitudinal notch was higher than the transverse notch. In addition, the stress of the storage vessel was analyzed by the stress ratio, which is the yield strength ratio of the material to the VMS generated. According to the analysis results, in the case of a storage vessel with a notch formed in the longitudinal direction, the inside and outside of the storage vessel increased to 0.85 and 0.50 at a gas pressure of 50 MPa, respectively, but were analyzed to be lower than 1.

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.58-64
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• 1999

This paper has been analyzed for the stress behavior problems of the ring knot membrane unit using the finite element method about the pitch design of the membrane unit, which is one of the most important parameters in manufacturing of the membrane type LNG storage tanks. The FEM results have been compared those of the existing pitch design length. The safety problem of the ring knot membrane model, which is considered in this study, does not come out any more no matter what the pitch length is used in the extra large LNG storage tanks. But in the case of the membrane for LNG tankers, it is advantageous to design the pitch short because of fatigue strength caused by repeated loadings. Looking at the deformation behaviors of the membrane corrugation, the deformation of the hight in the y direction occurs $15{\~}50\%$ more than that of the width in the z direction. It shows also that the deformation of the membrane with $-162^{\circ}C$ cryogenic temperature is not so great compared with the deformation by hydrostatic pressure.

• Journal of Korea Water Resources Association
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• v.35 no.3
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• pp.295-306
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• 2002

The modified TOPMODEL of two storage systems has been integrated to the generalized assumptions of decreasing hydraulic conductivity to vertical direction. Three different recharge functions were introduced to explore the impact of the macropore flow to vortical direction, the storage at the surface zone and the relative storage deficit of the soil matrix. Combinations of these approaches provide 30 type of the model structure for the hillslope hydrology. Developed models have been applied to several hydrologic events at the Sulmachun watershed. The performance evaluation with the Monte carlo simulation suggests that the exponential function of transmissivity reduction should be appropriate form for the physically -based hydrologic simulation on the Sulmachun watershed. It has been shown that the recharge function of macropore flow contributes to improve the predictability of the generalized version of modified TOPMODEL.