• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.317-320
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• 2022

This paper studies real-time error in the context of monitoring a symmetric binary information source over a delay system. To obtain the average real-time error, the delay system is modeled and analyzed as a discrete time Markov chain with a finite state space. Numerical analysis is performed on various system parameters such as state transition probabilities of information source, transmission times, and transmission frequencies. Given state transition probabilities and transmission times, we investigate the relationship between the transmission frequency and the average real-time error. The results can be used to investigate the relationship between real-time errors and age of information.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.44.2-44.2
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• 2021

Detecting lensed quasar systems and estimating their time delays using the unresolved joint light curves can be the next frontier among the cosmological probes in the near future. One can get the independent measurement of the Hubble constant from the time delays but without requiring the systems to be resolved a priori followed by monitoring the image light curves using high-resolution telescopes for years. In this work, we propose a novel technique that can identify lensed quasars only using the observed unresolved light curves and without assuming a template or any prior information. Following a set of conservative selection criteria that gives zero false-positive outcome, we can accurately estimate the time delay for almost all the lensed systems with marginal noise in the data. For the case of noisy data, our approach can still correctly identify a substantial number of lensed systems with high certainty and measure the time delay accurately.

• Journal of the Korean housing association
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• v.25 no.6
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• pp.101-109
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• 2014

It was early in the $20^{th}$ century when the space was begun to say through the mutual circumstances of form and contents. Adrian Forty explained that the characteristics of space can be divided into three steps by the period: a space of enclosure, a space as continuum and a space as an extension of the body. And there is common condition that all three spaces are accompanied by the form. In the new thinking of architectural form in terms of text in modern society, architecture becomes to more complex to understanding. Saying that there is nothing outside text (Il n'y a rien en dehors du text.) in the world, Jacques Derrida insisted the world to be texted and not to be special centrality, where can be existed by difference and delay its meaning. Text is the structural meaning (sign), not a metaphorical one (symbol). Without the symbol, the architecture can be recognized as text with signing to the form. For that, there is a question how can be explained the space in terms of text extracting the meaning and the symbol. Absolutely not intended by Mies van der Rohe, but in his works of houses and pavilion, its characteristics and traces of text can be seen. If it is possible to analyse his works in the textual view, space of Mies will be found in the same direction of text. And it will be an important opportunity to re-evaluate the space of Mies works standing in the heart of Modern Architecture.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.2
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• pp.75-85
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• 2016

The performance of up-to-date mapping functions and various mean temperature equations were analyzed to derive optimal mapping function and mean temperature equation when GNSS precipitable water vapor (PWV) was investigated in the Korean Peninsula. Bernese GNSS Software 5.2, which can perform high precision GNSS data processing, was used for accurate analysis, and zenith total delay (ZTD) required to calculate PWV was estimated via the Precise Point Positioning (PPP) method. GNSS, radiosonde, and meteorological data from 2009 to 2014 were acquired from Sokcho Observatory and used. ZTDs estimated by applying the global mapping function (GMF) and Vienna mapping function 1 (VMF1) were compared with each other in order to evaluate the performance of the mapping functions. To assess the performance of mean temperature equations, GNSS PWV was calculated by using six mean temperature equations and a difference with radiosonde PWV was investigated. Conclusively, accuracy of data processing was improved more when using VMF1 than using GMF. A mean temperature equation proposed by Wu (2003) had the smallest difference with that in the radiosonde in the analysis including all seasons. In summer, a mean temperature equation proposed by Song & Grejner-Brzezinska (2009) had the closest results with that of radiosonde. In winter, a mean temperature equation proposed by Song (2009) showed the closest results with that of radiosonde.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.273-282
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• 2002

We describe some performance of the detector electronics system for the FIMS (Far-ultraviolet Imaging Spectrograph) mission. The FIMS mission to map the far ultraviolet sky uses MCP (micro-channel plate) detectors with a crossed delay line anode to record photon arrival events. FIMS has two MCP detectors, each with a ~25mm$\times$25mm active area. The unconventional anode design allows for the use of a single set of position encoding electronics for both detector fields. The centroid position of the charge cloud, generated by the photon-stimulated MCP, is determined by measuring the arrival times at both ends of the anode following amplification and external delay. The temporal response of the detector electronics system determines the readout's positional resolution for the charge centroid. High temporal resolution (<$35{\times}75$ps FWHM) and low power consumption (< 6W) were achieved for the FIMS detector electronics system.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.579-588
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• 2014

In this study, three signal control strategies such as Bike box, Hook-turn, and 6-phase were assessed for various traffic conditions at signalized intersections incorporating bicycle left-turn traffic. Results showed that the size of a waiting zone mainly affected the performance of signal control in both Bike box and Hook-turn. Both Bike box and Hook-turn yielded an identical vehicle delay, but Bike box produced less bicycle delay than Hook-turn by 2.5~29.9 sec/veh for undersaturated traffic conditions. For saturated traffic condition, Bike box produced less vehicle delay than Hook-turn and 6-phase strategies, but bicycle delay was found to increase at the 700 vph of bicycle traffic compared to 6-phase. Bicycle delay was greatly increased under Hook-turn and Bike box strategies when bicycle traffic was greater than 300 vph and 500 vph, respectively. It was also shown that bicycle delay could be significantly reduced by providing appropriate size of queueing space. In addition, Bike box was likely to yield less vehicle and bicycle delay than Hook-turn for traffic volume patterns investigated in this study.

• Publications of The Korean Astronomical Society
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• v.23 no.2
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• pp.73-90
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• 2008

A software simulator is developed for verifying the VLBI Correlation Subsystem (VCS) trial product hardware. This software simulator includes the delay tracking, fringe rotation, bit-jump, FFT analysis, re-quantization, and auto/cross-correlation functions so as to confirm the function of the VCS trial product hardware. To verify the effectiveness of the developed software simulator, we carried out experiments using the simulation data which is a mixed signal with white noise and tone signal generated by software. We confirmed that the performance of this software simulator is similar as that of the hardware system. In case of spectral analysis and re-quantization experiment, a serious problem of the VCS hardware, which is not enough for expressing the data stream of FFT results specified in VCS hardware specification, was found by this software simulator. Through the experiments, the performance of software simulator was verified to be efficient. In future, we will improve and modify the function of software simulator to be used as a software correlator of Korea-Japan Joint VLBI Correlator (KJJVC).

• The Research Journal of the Costume Culture
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• v.27 no.3
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• pp.222-238
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• 2019

This study is aimed at applying the philosophical concept of "$diff{\acute{e}}rance$" to contemporary men's fashion design, which could effectively show the shift in thinking. For the study method, the author examined the theoretical background of deconstruction and prepared the standard of analysis by organizing the concept of "$diff{\acute{e}}rance$," which exists at the center of philosophy. This study selected the three most popular brands: Maison Margiela, Comme des Garcons, and Yohji Yamamoto. The results are as follows. First, there is expression of perpetual reservation emphasizing time. This includes texture, patchworks, hems with ladder, and exposure of seam that expresses the trace of time flow and delayed delivery of immediate meaning, and the expression creates delay between major and minor and leads to consistent role exchange. Second, the trace of blank that emphasizes the space gives a visual sense of weight on spares with the intentionally granted space, as well as the space that is the trace of trace and creates a sense of depth through the direction of empty space. Third, the space created in the process of wearing cloth is visualized, the structure of clothing is deconstructed, and the movement from the process recomposes the shape of space and expands the definition that enables expansion of time and space. Fourth, the undetermined relationship expresses the border of time and space visually and deconstructs time and space. The approaches are mostly constructive, demonstrating an avant-garde form of clothes-wearing to show the non-form or imbalance condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1373-1382
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• 2011

Zigbee is communication technology most ideal because Zigbee support low power communication and wide expansion in wireless home network. However, Zigbee is not popular, because of Zigbee always has Hidden Node Problem and Transit Delay Problem. We propose new Beacon Frame structure to solve the two problem in Zigbee. New Beacon Frame structure reduces a Super Frame Duration and add a same space of a Control Frame Duration. We expect to solved method of Hidden Node Problem that exchange terminal information to using RTS/CTS. Also, We expect to solved method of Transit Delay Problem that put Beacon between Control Frame Duration and Super Frame Duration for synchronization. We confirm new Beacon Frame to solved two problem in OPNET simulation at Zigbee QoS Parameters. We measure Delay(sec) for solution degree of Transit Delay Problem, and measure Throughput(bits/sec) and Load (bits/sec) for solution degree of Hidden Node Problem.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.164-171
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• 2013

In urban planning, road facility is used not only for the transportation purpose but also for the utility line space purpose such as electrical, gas, tele communication, heating, water, sewer, and so on. However, since these utilities are built by many different groups, it becomes very difficult to communicate each other. Delay in one party can cause another party's schedule delay but they don't commuicate often. Also, some delay in utility work can cause frequent pavement cut. And, this will impact on construction cost, schedule delay, low quality, user complain and cost. This study developed spatiotemporal decision model to prevent prequent utility cut for mega project such as new urban development project. In addition, this study developed utility cut management system to manage utility cut schedule under pavement. Finally, developed system was applied to new urban development project and verified there effectiveness.