• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.67-74
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• 2010

The cases of collapse of greenhouses in rural areas have been increasing due to the unexpected heavy snow load. Studies on how to prevent the collapse of greenhouses are rare, however, and the damages are repeated annually. This studysuggests two reinforcing methods: the use of ahigh-strength tapered module, and the addition of a pre-tension tie. The high-strength tapered section is installed where the bending moment is maximum. The design of a plastic greenhouse is controlled by its strength rather than its deflection. The shape of a greenhouse resembles that of an arch system, but its actual structural behavior is the frame behavior, because it is non-continually composed of a curved element (a beam) and vertical elements (columns). This system is too weak and slender to resist a vertical load, because an external load is resisted by the moment rather than by axial force. In this study, a new method, the installation of a temporary tie at the junction of the arch and the column only during snow accumulation, is proposed. The tie changes the action of the greenhouse frame to an arch action. The arch action is more effective when the pre-tension force is applied in the tie, which results in a very strong temporary structural system during snowfall. As a result of using this high-strength tapered section, the combined strength ratio of what? decreased from 10% to 30%. In the case of the additional reinforcement with a tie, it was reduced by half.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1613-1613
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• 2001

Fats and molasses are used, at the present time, in a considerable proportion as ingredients for the animal feed industry. They are mainly used as energy sources, but also they provide other characteristics of technological and nutritional interest (dust reduction, increase in palatability, etc). Both semi-liquid ingredients have numerous aspects in common from the point of view of their use in livestock feeds, as well as of their analytical control. Feed manufacturers use several criteria to evaluate the quality of fat and molasses. Furthermore, the traditional methods currently used, for their evaluation (eg. fatty acids, sugars, etc) are expensive and more sophisticated that the traditionally used for solid ingredients. The objective of the present work is to carry out a viability study to evaluate the ability of NIRS technology for the quality control of fat and molasses. Samples of liquid molasses (n = 42) and liquid fat ( n = 61), provided by a feed manufacturer, were scanned in a FOSS-NIR Systems 6500 monochromator equipped with a spinning module. The samples were analysed by folded transmission, using a sample cup of 0.1mm pathlength and gold surface reflector. For molasses, calibration equations were developed for the prediction of moisture (SECV=1.69%; $r^2$=0, 42), gross protein (SECV=0, 14%; $r^2$=0, 99), ashy (SECV=0, 60%; $r^2$=0, 84), NaCl (SECV=0, 05%; $r^2$=0, 99) and sugars (SECV=1, 04%; $r^2$=0, 86). For animal fats calibrations were obtained for the prediction of moisture (SECV=0, 14%, $r^2$=0, 88), acidity index (SECV=0, 83%, $r^2$=0, 82), MIU (SECV=0, 38%, $r^2$=0, 94) and unsaponifiables (SECV=0, 45%, $r^2$=0, 87). High accuracy calibration equations were also obtained for the prediction of the fatty acid profile. The equations have $r^2$values around 0.9 or highest. The results showed that NIRS technology could provide rapid and accurate results and reduce analytical costs associated to the quality control of two Important feed ingredients of a well known chemical variability.

• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.153-170
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• 2011

OMTP (Open Mobile Terminal Platform) is a global forum made by telecommunications providers to promote user-oriented mobile services and data business. Devised by OMTP, BONDI is a browser-based application or a mobile web run-time platform to help widgets make good use of functions of mobile devices in a secure way. BONDI enables applications programmed with web standard technologies such as HTML, JavaScript, CSS, and AJAX to reach the internal functions of mobile devices. Since BONDI, which is not just a simple network application, can reach the internal resources of devices in standard ways, it enables the application and widgets to be developed regardless of tile OS or platform. Web browser-based widgets are vulnerable to the network environment, and their exeeution speed can be slowed as the operations of the widgets or applications become heavy. However, those web widgets will be continuously used thanks to the user-friendly simple interface and the faster speed in using web resources more than the native widgets inside the device. This study suggested a method to effectively operate and manage the resource of OMTP BONDI web widget and then provided an improved result based on a running performance evaluation experiment. The experiment was carried to improve the entire operating time by enhancing the module-loading speed. In this regard, only indispensable modules were allowed to be loaded while the BONDI widget was underway. For the purpose, the widget resource list, able to make the operating speed of the BONDI widget faster, was redefined while a widget cache was employed. In addition, the widget box, a management tool for removed widgets, was devised to store temporarily idle widgets.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.156-160
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• 1997

The combination of biological wastewater treatment process and membrane separation has many advantages such as better effluent quality and system stability over the conventional biological wastewater treatment process. In this study, direct membrane separation using nonwoven fabric was applied to biological wastewater treatment. A nonwoven fabric module was submerged in the aerated bioreactor. And accumulated biomass in the bioreactor was separated by suction. The system was operated with various condition to investigate pollutant removal efficiencies and flux. After formation of biomass layer on nonwoven fabric surface, a day, the stable effluent water quality was obtained. The flux decreased at a high suction pressure faster than a low pressure. The stable flux was obtained at the pressure of $21{\sim}25cmHg$. In spite of variation of hydraulic retention time, organic loading rate, the removal efficiencies of BOD, $COD_{Cr}$. $COD_{Mn}$ were very high as follows : $95.2%(0.14{\sim}0.97\;BODKg/m^3/day)$, $86.0%(0.17{\sim}1.39\;COD_{Cr}Kg/m^3/day)$, $90.0%(0.097{\sim}0.61\;COD_{Mn}Kg/m^3/day)$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.884-891
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• 2020

The collapse of bridges can cause massive casualties and economic losses. Therefore, it is thus essential to evaluate the structural safety of bridges. For this task, structural reliability analysis, considering various bridge-related uncertainty factors, is often used. This paper proposes a new computational platform to perform structural reliability analysis for bridges and evaluate their structural safety under various loading conditions. For this purpose, a software package of reliability analysis, Finite Element Reliability Using MATLAB (FERUM), was integrated with MIDAS/CIVIL, which is a widely-used commercial software package specialized for bridges. Furthermore, a graphical user interface (GUI) control module has been added to FERUM to overcome the limitations of software operation. In this study, the proposed platform was applied to a simple frame structure, and the analysis results of the FORM (First-Order Reliability Method) and MCS (Monte Carlo simulation), which are representative reliability analysis methods, were compared. The proposed platform was verified by confirming that the calculated failure probability difference was less than 5%. In addition, the structural safety of a pre-stressed concrete (PSC) bridge was evaluated considering the KL-510 vehicle model. The proposed new structural reliability analysis platform is expected to enable an effective reliability-based safety evaluation of bridges.

• The KIPS Transactions:PartC
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• v.14C no.4
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• pp.331-340
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• 2007

Mobile network environments are the environments where mobile devices are distributed invisible in our daily lives so that we can conventionally use mobile services at my time and place. The fact that we can work with mobile devices regardless of time and place, however, means that we are also in security threat of leaking or forging the information. In particular, without solving privacy concern, the mobile network environments which serve convenience to use, harmonized without daily lives, on the contrary, will cause a serious malfunction of establishing mobile network surveillance infrastructure. On the other hand, as the mobile devices with various sizes and figures, public key cryptography techniques requiring heavy computation are difficult to be applied to the computational constrained mobile devices. In this paper, we propose efficient PKI-based user authentication and java-based cryptography module for the privacy-preserving in mobile network environments. Proposed system is support a authentication and digital signature to minimize encrypting and decrypting operation by compounding session key and public key based on Korean standard cryptography algorithm(SEED, KCDSA, HAS160) and certificate in mobile network environment. Also, it has been found that session key distribution and user authentication is safety done on PDA.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.669-678
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• 1994

The BOD removal characteristics of submerged biofilters filled with three kinds of filter media respectively were experimentally examined with constant temperature, pH value and variable BOD loading and recirculation ratio. Obtained results are as follows; 1. The BOD removal ratio decreases with the increasing $BOD_5$ volumetric loading rate, and the loading rate for the BOD removal over 90% is lower thean $1.6kg{\cdot}BOD_5/m^3{\cdot}d$ for the plastic media of Netring and cubic wire meshes. This is a much large value than $0.3{\sim}0.8kg{\cdot}BOD_5/m^3{\cdot}d$ for conventional activated sludge process. The required submerged biofilter volume is found to be much samller than that of conventional activated sludge process. 2. The decreasing order of BOD removal is Netring (random plastic media), cubic wire meshes (plastic module), and then gravel (stone media). This is mainly due to the media characteristics such as void ratio, specific surface area and media shapes. 3. The $BOD_5$ removal rate increases with the recircuration ration, but the rate of increases becomes samaller as the recirculation ratio increases over 20. When $BOD_5$ loading is $1.8kg{\cdot}BOD_5/m^3{\cdot}d$, the required recirculation rationto obtain 90% $BOD_5$ removal is about 20 for Netring and it was about 30 for cubic wire meshes. 4. Reynold's Number increases with recirculation ratio, and the Reynold's Numbers corresponding to the recircuration ratio of 10~50 are less than 52, showing laminar up flows in the filter. The settled and effluent sludges increase with increase of Reynol's Number, and there are the definite Reynold's Numbers at which the settling sludge concentrations become nearly constant respectively in each filters. 5. In this submerged biofilter system, small volume of sludge hopper can be substituted for a separated settling tank.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.929-935
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• 2014

This paper is study on the pressure monitoring system(PMS) for ship's engine performance analysis( SEPA) based on web, with high speed and accuracy. This system is composed of pressure sensor, monitoring module with multi channel A/D converter, TCP/IP and satellite internet communication system. Existing domestic products measure cylinder pressure when piston of first explosive cylinder reached TDC(the top dead center) point and then measure next cylinder pressure manually each angle divided by a constant rotating interval. But presented system monitors in the local and web computer, using pressure information transmitted from pressure sensor installed on each engine. In this system, it is possible to increase the accuracy of the engine performance analysis because not only each TDC points but cylinder pressures synchronized with the TDC points could be measured in real time, accurately. And therefore, it may be used in a various diagnosis of main engines, such as deviations of each cylinder maximum pressures(Pmax) and the TDC firing positions and combustion conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.409-417
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• 2013

Mu-communication board supported by multi-communication is designed with Atxmega 128A1 which is a low power energy consuming of 8-bit microcontroller. ATxmega128A1 microcontroller consists of 8 UART(Universal asynchronous receiver/transmitter) ports which can be setting appropriate user interface having command line interpreter(CLI) program with each port, 2 kbytes EEPROM, 128 kbytes flash memory, 8 kbytes SRAM. 8 URAT ports are used for the multi communication modem, GPS module, etc. and EEPROM is used for saving a configuration for program running, and flash memory of 128 kbytes is used for storing a Firm Ware, and 8 kbytes SRAM is used for stack, storing memory of global variables while program running. If we uses the hybrid communication of path optimization of VHF, TRS and CDMA to remote control AtoN(aid to navigation), it is able to remove the communication shadow area. Even though there is a shadow area for individual communication method, we can select an optimum communication method. The compatibility of data has been enhanced as using of same data frame per communication devices. For the test, 8640 of data has been collected from the each buoy during 30 days in every 5 minutes and the receiving rate of the data has shown more than 99.4 %.

• Journal of Technology Innovation
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• v.23 no.3
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• pp.169-199
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• 2015

Information and communication technologies (ICT) have been combined with products from other industries to provide new functionality, as recently shown in the cases of Internet of Things (IoT). Modularity assumes a crucial role in such technological convergence, and has impacts on the relationship between organizations as well as competition within an industry. Interface standards, which ensure the connectivity between modules, serve as a critical factor in the process by which modularity affects organization systems and industry structure. To understand the aforementioned phenomenon, we studied modularity and interface standards with a focus on the interaction between technology and organization systems and subsequent changes in industrial dynamics. This paper examines previous literature on modularity and interface standards in the aspects of product architecture, organization systems, and institutional factors. With this analytical framework, we conducted a comparative analysis of electronic and automotive industries to derive implications for standardization policy. This research has shown the significance of external open interface standards in shaping an industrial landscape where a variety of module producers horizontally compete. It also advises that policymakers take into account product characteristics, engagement of leading firms in an industry, and institutional factors such as WTO law in the design of standardization policy.