• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.464-473
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• 2022

In this paper, about a lightweight design that satisfies the performance of UHF-GPS Antenna used in autonomous underwater vehicle is proposed. Structural analysis, watertight external pressure test and non-destructive testing used in the design process are decided in consideration of structural safety for operating external forces in the underwater environment. First, the material of radome is selected for the performance of the UHF-GPS Antenna for communication with the carrier on the underwater operation in consideration of the 20 bar pressure generated. And the material of radome as PA-GF is selected by conducting electromagnetic field analysis and structural analysis and by considering high strength, rigidity and high dielectric constant. Electromagnetic field analysis and structural analysis by the thickness of radome are additionally performed in order to satisfy the required weight of UHF-GPS antenna. After selecting the final model, its structural safety is verified through watertight external pressure test and non-destructive testing.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.173-181
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• 2015

A stoichiometric mixture of evaporating materials for $BaIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2S_4$ single crystal thin films measured from Hall effect by van der Pauw method are $6.13{\times}10^{17}cm^{-3}$ and $222cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.0581eV-(3.9511{\times}10^{-3}eV/K)T^2/(T+536K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2S_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2S_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{24}$-exciton peaks for n = 24.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.574-580
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• 2014

Storage tanks of Carbon dioxide ($CO_2$) carriers utilized for the purpose of carbon capture and storage (CCS) into subsea strata have to undergo a pre-cooling session before beginning to load cryogenic liquid cargos in order to prevent physical and thermal deterioration of tanks which may result from cryogenic $CO_2$ contacting tank walls directly. In this study we propose dynamic model to calculate the tank inflow of $CO_2$ gas injected for precooling process and its dynamic simulation results under proportional-integral control algorithm. We selected two cases in which each of them had one controlled variable (CV) as either the tank pressure or the tank temperature and discussed the results of that decision-making on the pre-cooling process. As a result we demonstrated that the controlling instability arising from nonlinearity and singularity of the mathematical model could be avoided by choosing tank pressure as CV instead of tank temperature.

• The Journal of Society for e-Business Studies
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• v.21 no.2
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• pp.47-59
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• 2016

Parcel service is to deliver goods from one place to the designated destination requested according to user request. Parcel operations such as sorting, distributing, etc. or the managed information are heterogeneous by the companies. Additionally, it is impossible to support interoperability between companies with unformatted data of manual processing. Most parcel package boxes attached to paper typed waybill is attached is delivered to consignee. So, security problems such as personal information leaking are occurred, or extra processing time and logistics costs are needed due to wrong or the damaged information. Business environment of parcel service is rapidly changed as introducing unmanned delivery or the advanced technology such as Internet of Things. User want to know the accurate status or steps from parcel service request to delivery. To provide these requirements, the unified and integrated waybill information for reliable transportation of parcel service is needed. This information will provide to pickup or delivery carrier, warehouse or terminal, and parcel service user per pickup, transport, and delivery stage of parcel delivery service. Therefore, this paper defines the simplified and unified information model for parcel service waybill by analyzing information systems used for logistics unit processes that is occurred to parcel service, and manual work processes, and developing the relevant information of work flows occurred between business processes or transactions with the collected or processed information by from parcel service's stages. It is possible to share these standard model between business entities, and replacing paper typed waybill will improve national life safety as preventing security threats by paper typed waybill. As a result, it will promote the public interest from the stakeholder's perspective.

• Journal of Pharmacopuncture
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• v.13 no.1
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• pp.53-61
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• 2010

Purpose : To investigate the effects of the lavender, lemon and eucalyptus oil mixture on the atopy dermatitis skin lesions induced on NC/Nga Mice by dinitrochlorobenzene (DNCB). Material and Method : For this purpose, we fabricated the oil mixture blending three essential oils (lavender, lemon, eucalyptus : ELL) with one carrier oil (jojoba) and apply it on the atopic dermatitis skin lesions of NC/Nga Mice. Atopic dermatitis in NC/Nga Mice was induced by DNCB treatment on the dorsal skin of mice for 8 weeks. The mixture of ratio of each essential oil drop was 1 (eucalyptus) : 2 (lemon) : 2 (lavender) and this mixture was blended with jojoba oil 50ml (0.025%). The ELL-ointment was supplied for 8 weeks. We evaluated the effects of ELL on cell viability of mouse lung fibroblast, clinical skin features and severity, the level of serum Immunoglobulin (Ig) E & Ig G1, Interleukin (IL)-4, IL-13 and Interferon (IFN)-$\gamma$. Results : ELL showed safety on the cell viability of mouse lung fibroblast compared with control group. The cell viability was measured by SRB method. The effects of ELL on clinical skin features and severity in DNCB-induced dermatitis model of NC/Nga mice was significant compared with control group. EEL also showed significant effects on clinical symptom score compared with control group. Serum IgE & IgG1 level and development of atopy dermatitis skin lesions were evaluated. Serum IgE & IgG1 production was significantly down-regulated in EEL group compared with control group. ELL also down-regulated the levels of IL-4 and IL-13, and up-regulated the level of IFN-$\gamma$ compared with control group significantly. Conclusion : ELL was effective on atopy dermatitis by modulating Th2 related factors.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.283-292
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• 2005

Ionosphere is deeply coupled to the space environment and introduces the perturbations to radio signal because of its electromagnetic characteristics. Therefore, the status of ionosphere can be estimated by analyzing the GPS signal errors which are penetrating the ionosphere and it can be the key to understand the global circulation and change in the upper atmosphere, and the characteristics of space weather. We used 9 GPS Continuously Operating Reference Stations (CORS), which have been operated by Korea Astronomy and Space Science Institute (KASI) , to determine the high precision of Total Electron Content (TEC) and the pseudorange data which is phase-leveled by a linear combination with carrier phase to reduce the inherent noise. We developed the method to model a regional ionosphere with grid form and its results over South Korea with $0.25^{\circ}\;by\;0.25^{\circ}$ spatial resolution. To improve the precision of ionosphere's TEC value, we applied IDW (Inverse Distance Weight) and Kalman Filtering method. The regional ionospheric model developed by this research was compared with GIMs (Global Ionosphere Maps) preduced by Ionosphere Working Group for 8 days and the results show $3\~4$ TECU difference in RMS values.

• Journal of Korean Library and Information Science Society
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• v.41 no.2
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• pp.251-272
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• 2010

Resource Description and Access(RDA) was published in 2008, reflecting IFLA IME ICC's International Cataloguing Principles(ICP), conceptual model for cataloging of Functional Requirement for Bibliographic Records(FRBR), and conceptual model for authority data of Functional Requirement for Authority Data(FRAD). Therefore, new tags and fields have been added to MARC21 format, and researches about the prototype have been studied to implement FRBR as envisioned by the new RDA standard. According to the innovative international cataloging environments, KCR and KORMARC must be revised to accommodate RDA description. This study was to grasp occurrence rate of work and expression element of FRBR and RDA among MARC field of Hansung University library and to analyze limitation of MARC data for RDA. Based on this limitations, cataloging rules and tags and fields of KORMARC were suggested to accommodate RDA in national cataloging environment. This study reviewed cataloging rules such like representation, main entry and rule of three, preferred title, types of content, media and carrier. This study is to suggest the consideration of KCR and KORMARC for RDA in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.3 no.1
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• pp.18-25
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• 1978

The 1/f noise spectrum of short-circuited output drain current due to the Shockley-Read-Hal] recombination centers with a single lifetime in homogeneous nondegenerate MOS-field effcte transtors with n-type channel is calculated under the assumptions that the quasi-Fermi level for the carriers in each energy band can not be defined if we include the fluctuation for time varying quantities. and so 1/f noise is a majority carrier effect. Under these assumptions the derived 1/f noise in this paper show some essential features of the 1/f noise in MOS-field effect transistors. That is, it has no lowfrequency plateau and is proportionnal to the channel cross area A and to the driain bias voltage Vd and inversely proportional to the channel length L3 in MOS field effect transistors. This model can explain the discrepancy between the transition frequency of the noise spectrum from 1/f- response to 1/f2 and the frequency corresponding to the relaxation time related to the surface centers in p-n junction diodes. In this paper the results show that the functional form of noise spectrum is greatly influenced by the functional forms of the electron capture probability cn (E) and the relaxation time r (E) for scattering and the case of lattice scattering show to be responsible for the 4 noise in MOS fold effect transistors. So we canconclude that the source of 1/f noise is due to lattice scattering.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.927-932
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• 2009

Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.153-162
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• 2008

Purpose: Recombining bone morphogenetic protein (BMP) is usually acquiredfrom high level animals. Though this method is effective, its high cost limits its use. The purpose of this study was to evaluate the effect of bone morphogenetic protein-2 with protein transduction domain (BMP-2/PTD;TATBMP-2) on bone regeneration. Rat calvarial defect model and osteoblastic differentiation model using MC3T3 cell were used for the purpose of the study. Materials and Methods: MC3T3 cells were cultured until they reached a confluence stage. The cells were treated with 0, 0.1, 1, 10, 100, 500 ng/ml of BMP-2/PTD for 21 days and at the end of the treatment, osteoblastic differentiation was evaluated usingvon Kossa staining. An 8mm, calvarial, critical-size osteotomy defect was created in each of 48 male Spraque-Dawley rats (weight $250{\sim}300\;g$). Three groups of 16 animals each received either BMP-2/PTD (0.05mg/ml) in a collagen carrier, collagen only, or negative surgical control. And each group was divided into 2 and 8 weeks healing intervals. The groups were evaluated by histologic analysis(8 animals/group/healing intervals) Result: In osteoblastic differentiation evaluation test, a stimulatory effect of BMP-2/PTD was observed in 10ng/ml of BMP-2/PTD with no observation of dose-dependent manner. The BMP-2/PTD group showed enhanced local bone formation in the rat calvarial defect at 2 weeks. New bone was observed at the defect margin and central area of the defect. However, new bone formation was observed only in 50% of animals used for 2weeks. In addition, there was no new bone formation observed at 8 weeks. Conclusion: The results of the present study indicated that BMP-2/PTD(TATBMP-2) have an positive effect on the bone formation in vitro and in vivo. However, further study should be conducted for the reproducibility of the outcomes.