• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.31.2-31.2
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• 2017

The central regions of barred-spiral galaxies contain interesting gaseous structures such as dust lanes and nuclear rings with intense star formation. While our previous studies were useful in understanding the formation of these structures star formation history, they were limited to 2D isothermal galaxies in which the stellar disk and halo are modeled by fixed gravitational potentials. To study the effects of bar growth as well as the vertical dimension, we use the mesh-free hydrodynamic code named GIZMO and run 3D simulations by treating the stellar disk and halo as being live. We find that the new 3D models form the gaseous features similarly to the previous 2D models, although the detailed formation processes are quite different. For example, a ring has a large radius when it first forms and shrinks over time in the previous 2D models. In the 3D live-potential models, however, a ring forms small and grows in size with time. We present the results of the new simulations and discuss them in comparison with the previous 2D results.

• Journal of Information Management
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• v.41 no.4
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• pp.41-67
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• 2010

Augmented reality technology was invented for military purposes at the beginning. But the development of wireless and location based technology in 2000s makes AR services reach the age of innovation. Especially, it attracts attention as a media which enriches our perception. There is a potential that it can extend the virtual information in the real world from optical sense to auditory, tactile, and olfactory sense. This study proposed the interactive information service system and method based on AR. To do it, technical background on AR was analyzed and a method to apply the technology was examined. Especially, as a eco service, this study proposed new information service using 2D bar code in a library for user need and convenience in ubiquitous environment. The proposed service system can optimize practical utilization of information resources in virtual and real reality as consolidating analog and digital resources in a library.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.3
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• pp.276-281
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• 2019

Food printers must use food ink cartridges approved by the Ministry of Food and Drug Safety (MFDS). A 2D bar code is used to read whether the ink cartridge is authentic. However, since the dye is diverged by heat pressure and printed, the barcode is contaminated. In this paper, we propose a pre-processing algorithm to solve the problem of barcode contamination by food coloring dust in a latte art printer. The algorithm is based on various morphological operations. We apply this algorithm before reading contaminated barcode images with a general QR code reader. It has been confirmed that, as compared with the existing QR code reader, the contamination rate that can be perceived is increased from 25% to 40% and even at a contamination rate of 45%, the recognition rate reaches 50%.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.239-246
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• 2015

QR(Quick Response) Code has been developed to provide greater storage capacity and more functionality compared to 1D bar codes. With the emergence of increasingly mobile devices equipped with cameras such as smart-phones and tablets, QR codes have become very popular and more important in mobile businesses. Typically, most QR codes are used as a URL link for redirecting users to webpages. However, the URL based QR codes are required to be connected over the internet and to be run a server. This can incur unnecessary traffics in the Internet. Furthermore, it is not suitable for the country lagging behind others in its network infrastructure. In this paper, we propose a server-less ${\mu}$-webpage to provide mobile web services and be optimized for the capabilities and limitations of QR Code. We have implemented the ${\mu}$-webpage in Android, and the results showed that the proposed mechanism can provide web-services without requiring extra servers or incurring mobile traffic data compared to the URL-based QR Codes.

• Electronics and Telecommunications Trends
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• v.14 no.2 s.56
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• pp.38-52
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• 1999

우정업무는 발송인으로부터 우편물을 접수하여 수취인에게 배달하기 위해 소요되는 인력 의존도가 80%인 노동 집약적인 업무이다. 이에 따라, 우편고객에게 고품질의 우편서비스를 제공하기 위한 목적으로 우편물 자동구분 처리시스템을 개발하여 적용하고 있다. 본 고에서는 우편서비스의 질을 향상시키기 위한 노력의 일환으로 고객 바코드의 활용사례를 분석하고, 우편고객에게 부가서비스를 제공하기 위한 방법을 제시한 내용이다.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.77-84
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• 1999

Recently, it is increased the use of High-Strength Light-Weight Concrete(HLC) in the high-rise buildings and mega-structures. But there are a few research on the bond behavior of HLC, so it need to study about that. The present study was performed to investigate the bond characteristics of HLC. Major test variables include concrete compressive strength(f'c), concrete cover(c), bond length (${\ell}_{db}$), and bar diameter($d_b$). Test results indicate that the bond stress of HLC is increased with the increment of $\sqrt{f'_c}$ and concrete cover, bond stress is decreased with increment of bond length and bar diameter. And the final failure mode such as splitting or pullout failure is significantly affected by the concrete cover to bar diameter ratios(C/$d_b$). Test results were compared with ACI code and other proposed equations. The bond stress of HLC is higher than that of normal-strength normal-weight concrete, but lower than that of high-strength normal-weight concrte. Considering the present test results, modification factor(${\lambda}$= 1.3) of bond length in ACI 318-95 code for light-weight concrete is may have to be reviewed to apply to HLC.

• Journal of Radiation Protection and Research
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• v.11 no.1
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• pp.37-43
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• 1986

Dosimetric quantities for 300 keV neutrons in the ICRU standard tissue sphere were evaluated. The Monte Carlo code NEDEP which performs neutron-photon-charged particles coupled transport was used in the direct estimation of absorbed dose and dose equivalent. Some important quantities calculated are as follows; Deep dose equivalent index $H_{I,d}:1.78{\times}10^{11}\;Sv-cm^2$ Shallow dose equivalent index $H_{I,s}:2.08{\times}10^{-11}\;Sv-cm^2$ Ambient dose equivalent $H^*(0.07):1.7{\times}10^{-11}\;Sv-cm^2$ Ambient dose equivalent $H^*(10):1.78{\times}10^{-11}\;Sv-cm^2$ Effective quality factor $\bar{Q}^*(10):12.4$

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.2
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• pp.74-82
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• 2014

Automatic identification is pervasive in many areas and its applicable areas are increasing gradually. 2D bar-code, NFC, and RFID technologies are representative examples of the automatic identification. This paper explains the implementation of mobile tourism application software on RFID technology. The mobile application provides the location and navigation information by combining the tag inventory and web database. The interactions among the user, application and database server are described in detail. This paper proposes a simple way of minimizing the efforts to build the entire system by storing the URLs for the tag and accessing existing tourism information services through the URLs.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.296-301
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• 2003

A study on the engineering design and numerical thermo-hydraulic analysis for KSTAR TF coil structure cooling system has been conducted. The numerical analyses have been done to verify the engineering design of cooling using the commercial code, FLUENT and in-house code for calculating helium properties which varies with cooling tube's heat transfer. Through the engineering design process based on the steady heat balance concepts, the circular stainless steel tube with inner diameter of 4 mm for TF coil has been selected as cooling tube. From normal operation mode analysis results, total 28 cooling tubes were finally chosen. Also, three dimensional cool down analysis for TF coil with designed cooling tube was satisfied with next three design criteria. First is cooling work termination within a month, second is maximum temperature difference within 50 K in TF coil structure and third is exit helium pressure above 2 bar. Consequently, these cool down scenario results can afford to adopt as operating scenario data when KSTAR facilities operate.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.42.2-43
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• 2015

Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions and dynamics in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two guaranteed-time key programs "Water In Star-forming regions with Herschel" and "Herschel observations of EXtra-Ordinary Sources". We analyze the temperature and density structures using LTE and non-LTE methods. We also estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. Around high-mass protostars we find H2O abundances of ~10-8-10-9 for the outer envelope and ~10-4-10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.0 km s-1. The abundances and kinematic parameters of the sources do not show clear trends with evolutionary indicators. The Herschel/HIFI mapping observations of H2O toward the Orion Bar PDR show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption and photodissociation.