• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1007-1015
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• 2008

In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.147-153
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• 2016

The lightning protection of information and communication facilities is very important factor to improve a reliability of the action of these equipment. Especially the transient potential rise of ground electrode being injected with the lightning current is to be a basic data of the dielectric strength for both power and communication facilities so that more accurate analysis should be required. The transient potential rise can be calculated from the ground impedance and the ground impedance is strongly dependent upon the shape of the ground electrode and the frequency-dependence of soil. The Debye's equation which is able to calculate the characteristics of dielectrics is used to analyze the frequency-dependent of soil. Also, the method to calculate the transient potential rise from the ground impedance is specified in this paper. In order to analyze the transient potential rise resulting from calculations with Debye's equation, TLM(transmission line method) and case of ${\rho}$(resistivity)-constant are simulated, respectively. The length of a horizontal ground electrode is 30 m and simulations were performed at 10, 100, $1000{\Omega}{\cdot}m$ with the standard lightning current waveform. In result, the transient potential rise of horizontal ground electrode calculating with Debye's equation is lower than it of other models.

• Elastomers and Composites
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• v.41 no.4
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• pp.260-267
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• 2006

SBR (styrene-butadiene rubber; 25 wt% of solid contents) nanocomposites reinforced with OLS(organically modified layered silicates) were manufactured via the latex method. Two types of OLS are prepared, i.e. dodecylamine (primary amine) modified montmorillonite (DA-MMT) and N, N-dimethyldodecylamine (tertiary amino) modified MMT (DDA-MMT). X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to characterize the layer distance of OLS and the morphology of the nanocomposites. SBR nanocomposites reinforced with ternary phase filler (carbon black/silica/OLS) systems also manufactured. Dynamic mechanical thermal analysis (DMTA) was performed on these composites to determine the loss factor (tan $\delta$) over a range of temperature($-20^{\circ}C{\sim}80^{\circ}C$). The results showed that there was significant changes on the values or tan $\delta$ with the addition of small amount of the OLS. By increasing the contents of OLS, the values of tan $\delta$ at $0^{\circ}C$ increased but those of tan $\delta$ at $60^{\circ}C$ decreased with increasing OLS contents.

• Journal of Internet Computing and Services
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• v.22 no.5
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• pp.17-26
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• 2021

This paper is about a physical layer frame security technique using OFB-style encryption/decryption with AES algorithms on Gigabit Ethernet network. We propose a data security technique at the physical layer that performs OFB-style encryption/decryption with AES algorithm with strong security strength when sending and receiving data over Gigabit Ethernet network. Generally, when operating Gigabit Ethernet network, there is no security features, but data security is required, additional devices that apply this technique can be installed to perform security functions. In the case of data transmission over Gigabit Ethernet network, the Ethernet frames conform to IEEE 802.3 specification, which includes several fields to ensure proper reception of data at the receiving node in addition to the data field. When encrypting, only the data field should be encrypted and transmitted in real time. In this paper, we show that only the data field of the IEEE802.3 frame is encrypted and transmitted on the sending node, and only the data field is decrypted to show the plain text on the receiving node, which shows that the encryption/decryption is carried out correctly. Therefore, additional installation of devices that apply this technique can increase the reliability of the system when security for data is required in Ethernet network operating without security features.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2860-2866
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• 2020

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.467-477
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• 2021

Purposes of this study were to identify the relationship among involvement in COVID-19 (IiC), attitude toward advertisement (AtA), and behavioral Intention to social distancing (BItSD), and to investigate the mediating effect of AtA in a loss versus gain advertising context. The participants were 379 adults who have been consecutively living in Korea since January 2020. The participants were randomly assigned to one of two advertisements using an online survey system. We found that IiC affects BItSD since Korean adults recognize the risks and seriousness of COVID-19 infection or transmission through IiC. Induced positive attitudes or emotions through involvement in the COVID-19 preventive behaviors including social distancing and vaccination are helpful to increase the BItSD. Thus, health care and information providers should give an accurate message, which induces a positive attitude, to recognize that our world is a risk of the COVID-19.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.295-305
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• 2018

Network RTK is a highly practical technology that can provide high positioning accuracy at levels between cm~dm regardless of user location in the network by extending the available range of RTK using reference station network. In particular, unlike other carrier-based positioning techniques such as PPP, users are able to acquire high-accuracy positions within a short initialization time of a few or tens of seconds, which increases its value as a future navigation system. However, corrections must be continuously received to maintain a high level of positioning accuracy, and when a time delay of more than 30 seconds occurs, the accuracy may be reduced to the code-based positioning level of meters. In case of SSR, which is currently in the process of standardization for PPP service, the corrections by each error source are transmitted in different transmission intervals, and the rate of change of each correction is transmitted together to compensate the time delay. Using these features of SSR correction is expected to reduce the performance degradation even if users do not receive the network RTK corrections for more than 30 seconds. In this paper, the simulation data were generated from 5 domestic reference stations in Gunwi, Yeongdoek, Daegu, Gimcheon, and Yecheon, and the network RTK and SSR corrections were generated for the corresponding data and applied to the simulation data from Cheongsong reference station, assumed as the user. As a result of the experiment assuming 30 seconds of missing data, the positioning performance compensating for time delay by SSR was analyzed to be horizontal RMS (about 5 cm) and vertical RMS (about 8 cm), and the 95% error was 8.7 cm horizontal and 1cm vertical. This is a significant amount when compared to the horizontal and vertical RMS of 0.3 cm and 0.6 cm, respectively, for Network RTK without time delay for the same data, but is considerably smaller compared to the 0.5 ~ 1 m accuracy level of DGPS or SBAS. Therefore, maintaining Network RTK mode using SSR rather than switching to code-based DGPS or SBAS mode due to failure to receive the network RTK corrections for 30 seconds is considered to be favorable in terms of maintaining position accuracy and recovering performance by quickly resolving the integer ambiguity when the communication channel is recovered.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.540-549
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• 2018

This study was conducted on 238 dental hygienists working in Daegu and Gyeongbuk area. In order to understand the status of harmful transmission of dental materials by type of work, we compared the differences in exposure time and work environment characteristics of hospital types and investigated the difference in the degree of recognition of material safety data. The results of the study were as follows: In case of hospitals, the exposure time of dust generated from chemicals was the longest. Resin filling, contact with disinfectant. 37 workers (29.4%) and 14 workers (12.5%) answered that they perceive the question about whether they are aware of the material safety data sheet (MSDS) for dental materials. There were 18 hospital workers and 6 clinic workers who had experience reading MSDS before using dental materials. The respondents who answered that they provided the material safety data of the dental materials used had a 2.39 times MSDS in hospital workers. Therefore, by recognizing the health hazards of chemical substances in accordance with the characteristics of each type of hospital and continuing to conduct health and safety education, the work environment should be improved by establishing proper recognition of MSDS information. It suggests the necessity of a system that can strengthen the management of chemical information provision and guarantee the strategic approach and workers' right to know.

• The Korean Journal of Archival Studies
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• no.56
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• pp.147-182
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• 2018

Intangible cultural heritage is formless. It's of importance to preserve heritage in line with society drastically being transformed. It's passed down by human being. It is, on the other hand, impossible to preserve intangible cultural heritage solely based on memory, for it's changed in succession. Thus, it be archived to pass down. This study investigated on the state of affair related with Intangible cultural heritage documentations, examined the shortages thereupon. Furthermore, Training center should be in charge of documentation for a solution. This will provide an opportunity to overcome the limitations attributed to the top-down documentation system by central administrative organ, to open up the possibility of viewpoint of different successors, organizations. In addition to that, Intangible cultural heritage documents should be of different aspects of community history. Features of Intangible cultural heritages, which are convergent to the Regionality, tendency of variation, transmission, can be magnified when documentating. Finally, Training center is going to play a major role being vitalised. The record management of intangible cultural heritage, institutions and policies about Intangible cultural heritage have been highly complicated since National Intangible Heritage Center opened and the law on Intangible cultural heritage enacted with its recognition attracted. Therewith this study wishes to see a cornerstone of records on intangible cultural heritage by laying stress on training center in which educations and pass-down of intangible cultural heritage are lively achieved.

• Journal of Technology Innovation
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• v.27 no.2
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• pp.37-71
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• 2019

How has the passenger car's architecture evolved? In the meantime, the discussions on the car architecture have been mixed, i.e., integral, modular, and the coexistence of two types. Therefore, in this study, we aim to develop two indices can measure the degree of modularization of passenger car and its all modules using global trade data. By applying the indices to the framework of architecture positioning that reflects the hierarchical structure of a product, we examined that the degree of modularization of the passenger car architecture has been enhanced. Meanwhile, the degree of modularization differs across the modules that make up the car. Specifically, we observed the higher degree of modularization in front-end, cockpit and seat modules. Whereas, we found that body module had a relatively low degree of modularization. In particular, we observed that the platform of passenger car has notably modularized due to carmakers' efforts to achieve model diversification and reduction of cost and period in new product development at the same time. Interestingly, we showed that three modules, i.e., engine, chassis (relatively less modularized), and transmission (relatively highly modularized), had a different level of modularization, even if they commonly make up the platform. We contribute to the suggestion for analytical approaches that examine the degree of modularization and its progress longitudinally. In addition, we propose the necessity of decomposition of a system into elements in a study of product architecture, considering the possibly distinctive progress of modularization across the elements.