• The Korean Journal of Archival Studies
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• no.41
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• pp.113-173
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• 2014

For the past few years, there has been active seeking of archival practices outside of public institutions. For example, there is oral history archive which has an actual field of its own, community archive, archives of everyday life, cultural resources archive, digital archive, and post-modern archive with its discourse practical character. In this reading, such flow is organized through everyday paradigm, and examines new archival methodology that is suitable for it. Through such critical mind, semiotic approach is taken and the need, direction and alternative of archival methodology is offered. Especially, archival methodology, which can be applied to archives is thoroughly observed. Also, the way how sign practices can be executed in the archival field is explained through specific examples. Of course, it is clearly stated that this is an instance, and that it is an archival methodology that can be applied to public institutions. We hope this would be a discuss that would enable a comprehensive understanding of records.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04a
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• pp.61-62
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• 2009

Electro-optical properties of liquid crystal display (LCD) using fringe-field switching (FFS) devices depend on many parameters such as cell retardation, electrode structure, magnitude and sign of dielectric anisotropy, rubbing angle and cell gap. In this paper, the light efficiency of FFS device depending on magnitude of positive dielectric anisotropy with other cell parameters such as rubbing angle and angle and cell gap have been explored compared with FFS device using LC with negative dielectric anisotropy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.E
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• pp.67-73
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• 1990

Many distress mechanisms in pavement are known to be caused by the poor mechanical properties of bituminous concretes. Among many mechanical properties, tensile strength is one of the more important indicates that represent the resistance of pavement to traffic loading. However, there has been no relationship established between the strength and distress mechanisms. Therefore, this study was conducted to evaluate a correlation between the tensile strength value and the intensity of distress in bituminous concrete. Distress data were collected from an extensive field investigation over 77km of a four-lane highway in South Carolina, USA, and from laboratory prepared specimens in two phases of study. Strength data were obtained from a total of more than 400 field cores taken from the same highway and from 640marshall specimens of surface course mixture prepared in the laboratory. These data were analyzed using statistical test techniques. It was found from statistical analyses that the tensile strength of bituminous concrete had a strong relation with the pavement condition in the field. In the analysis of rutting and stripping, low strength concrete showed a higher distress rate in the mixture, and mixtures under distress in the field showed obviously reduced strength values. Stripping was found to be the most significant distress mechanism that was correlated with low strength bituminous concrete. Rutting appeared more frequently in a low strength pavement section of the highway as a sign of failure due to traffic loading.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.671-679
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• 2018

Finite element analyses are carried out to understand the piezoelectric behaviors of ZnO nanowires. Three different types of ZnO nanowires, with aspect ratios of 1:2. 1:31, and 1:57, are analyzed for uniaxial compression, pure bending, and buckling. Under the uniaxial compression with a strain of $1.0{\times}10^{-4}$ as the reference state, it is predicted that all three types of nanowires develop the same magnitude of the piezoelectric fields, which suggests that longer nanowires exhibit higher piezoelectric potential. However, this prediction is not in agreement with the experimental results previously reported in the literature. Such discrepancy is understood when the piezoelectric behaviors under bending and buckling are considered. When only the strain field due to bending is present in bending or buckling, the antisymmetric nature of the through-thickness stain distribution indicates that two piezoelectric fields, the same in magnitude and opposite in sign, develop along the thickness direction, which cancels each other out, resulting in a zero net piezoelectric field. Once additional strain contribution due to axial deformation is superposed on the bending, such field cancelling is compensated for due to the axial component of the piezoelectric field. Such numerical predictions seem to explain the reported experimental results while providing a guideline for the design of nanowire-based piezoelectric devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.214-221
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• 2018

The purpose of this study is to analyze the shipbuilding structure of field tangerine by ten days and by month. By estimating and analyzing the price flexibility function of field tangerines, this study determines whether the shipment control can stabilize and increase the income of field tangerine farmers and provides policy implication. Considering the overall market, a 1% increase in shipment volume indicates that the coefficient of price flexibility varies with ten days and month. The greatest decline is from late October to early January. Therefore, a greater necessity of shipment control is required during late October and early January. The coefficient of the dummy variable (DUM_Q) indicates the year in which the quality declines is statistically significant and sign. The coefficient of the dummy variable (DUM02) represents the year in which more than 7 days after the New Year holidays are in February is statistically significant and sign from early October to late January. Therefore, it can be seen that the necessity of shipment control is more required when New Year holidays are in February. The greatest decline in the coefficient of price flexibility is from October to December. Therefore, a greater necessity of shipment control is required during October and December. The signs of coefficients of DUM01 and DUM_Q dummy variable of the price flexibility function suggest that the need for shipment control is more important when quality is worse than better quality and that the necessity of shipment control is more required when New Year holidays are in February, respectively.

• Journal of Communications and Networks
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• v.1 no.3
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• pp.201-212
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• 1999

This paper studies the rapid design and implementation of the medium access control(MAC) and related interface circuits for 802.11 wireless LANs based on the field programmed gate ar-ray(FPGA) technology. Our design is thus aimed to support both the distributed coordination function (DCF) and the point coordination function(PCF) with the aid of FPGA technology. Further-more, in an infrastructure network, some stations may serve as the access points (APs) which may function like a learning bridge. This paper will also discuss how to design for such application. The hardware of the MAC and interface may at least consist of three major parts: wireless transmission and reception processes and in-terface, host(bus) interface, and the interface to the distributed system (optional). Through the increasing popularity of FPGA de-sign, this paper presents how Complex Programmable Logic De-vices(CPLD) can be utilized for speedy design of prototypes. It also demonstrates that there is much room for low-cost hardware prototype design to accelerate the processing speed of the MAC control function and for field testing.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.167-169
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• 2003

This paper presents a theoretical study concerning multibubble dynamics in a sound field and the numerical validation for it by employing our new CFD code MTS-DiCUP. In recent papers, the author has shown theoretically that an unknown characteristic frequency, named 'transition frequency,' exists in a multibubble system. For a N -bubble case, up to 2N -1 transition frequencies per bubble have been predicted, only N ones of them correspond to the natural frequencies of the system. The transition frequencies that do not correspond to the natural frequencies give rise to the phase reversal of bubbles' pulsation without resonant response. In this paper, it has been suggested theoretically that those transition frequencies may cause the sign reversal of the secondary Bjerknes force, which is an interaction force acting between acoustically coupled gas bubbles. This theoretical result has been validated by the direct numerical simulation, at least in a qualitative sense.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• Fire Science and Engineering
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• v.32 no.2
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• pp.67-72
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• 2018

A fire shutter is installed to prevent the movement of fire or smoke when a fire occurs inside a building. Fire shutters have access doors for passengers. On the other hand, the present fire shutter door display regulation is only required to be displayed in a different color from the surroundings. Hence, the risk of people not being able to recognize the door of the fire shutter is quite high, and the danger increases further in a smoke situation. Therefore, this study attempted to find a way to mark a fire shutter door that can be recognized even when smoke is spreading. First, a preliminary questionnaire was used to draw three factors to mark the fire shutter door (sign, door background, and edge). The experiment type was set by combining 5 colors for the three derived factors. The experiment was conducted on a total of 122 male and female participants. The results showed that a yellow background, red sign, and red edge have the highest awareness in a normal visual field without smoke. This was also the same in the field of view in the case of a fire with smoke, but the red background, yellow sign, and yellow edge were most noticeable in the case of dark smoke.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.4
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• pp.243-251
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• 2019

The road sign location information installed on national roads is continuously updated using MMS (Mobile Mapping System) technology. It is possible to map accurate road facilities by MMS, but the equipment is very expensive and requires specialized technology. Also, the accuracy of the position of the object greatly depends on the GPS (Global Positioning System) accuracy. In the case of road facility mapping, the advantage of drone is more remarkable than that of field survey or conventional aerial photogrammetry. In particular, it is more efficient than field surveying and it is possible to acquire high resolution images with low budget compared to conventional aerial photogrammetry. In this study, the accuracy of the location information measured by the existing MMS is compared with the GPS survey result and the accuracy analysis is performed by the drone aerial photogrammetry. In order to confirm the space accuracy that can be obtained when conducting drone aerial photogrammetry, the accuracy of the change in the number of ground control points and the degree of overlap was evaluated. As a result of the experiment, it was possible to obtain sufficient accuracy with two ground control points distributed at both ends of the road and 60% overlap.