• Advances in concrete construction
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• v.3 no.4
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• pp.253-268
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• 2015

This paper investigates the influence of various mix design parameters on the characteristics of concrete containing recycled coarse aggregates and Nano-Silica using Taguchi method. The present study adopts Water-cement ratio, Recycled Coarse Aggregate (%), Maximum cement content and Nano-Silica (%) as factors with each one having three different levels. Using the above mentioned control parameters with levels an Orthogonal Array (OA) matrix experiments of L9 (34) has selected and nine number of concrete mixes has been prepared. Compressive Strength, Split Tensile Strength, Flexural Tensile Strength, Modulus of Elasticity and Non-Destructive parameters are selected as responses. Experimental results are analyzed and the optimum level for each response is predicted. Analysis of 28 days CS depicts that NS (%) is the most significant factor among all factors. Analysis of the tensile strength results indicates that the effect of control factor W/C ratio is ranked one and then NS (%) is ranked two which suggests that W/C ratio and NS (%) have more influence as compared to other two factors. However, the factor that affects the modulus of elasticity most is found to be RCA (%). Finally, validation experiments have been carried out with the optimal mixture of concrete with Nano-Silica for the desired engineering properties of recycled aggregate concrete. Moreover, the comparative study of the predicted and experimental results concludes that errors between both experimental and predicted values are within the permissible limits. This present study highlights the application of Taguchi method as an efficient tool in determining the effects of constituent materials in mix proportioning of concrete.

• Advances in concrete construction
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• v.9 no.3
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• pp.267-278
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• 2020

This paper reports on the result of an experimental investigation carried out to study the compressive strength and sorptivity properties of blended cement concrete exposed to 5% and 10% MgSO₄ solution using fly ash (FA) and silpozz. Usually in sulphate environment the minimum grade of concrete is M30 and the mix design is done for target mean strength of 39 MPa. Silpozz is manufactured by burning of agro-waste rice husk in designed furnace in between 600° to 700℃ which is one of the main agricultural residues obtained from the outer covering of rice grains during the milling process. There are four mix series taken with control mix. The control mix made 0% replacement of FA and silpozz with Ordinary Portland Cement (OPC). The first mix series made 0% FA and 10-30% replacement of silpozz with OPC. The second mix series made with 10% FA and 10-40% replacement of silpozz with OPC. The third mix series made 20% FA and 10-30% replacement of silpozz with OPC and the fourth mix series made 30% FA and 10-20% silpozz replaced with OPC. The samples (cubes) are prepared and cured in normal water and 5% and 10% MgSO₄ solution for 7, 28 and 90 days. The studied parameters are compressive strength and strength deterioration factor (SDF) for 7, 28 and 90 days. The water absorption and sorptivity tests have been done after 28 days of normal water and magnesium sulphate solution curing. The investigation reflects that the blended cement concrete incorporating FA and silpozz showing better resistance against MgSO₄ solution when compared to normal water curing (NWC) samples.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.21-27
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• 2017

To guarantee the effectiveness of the HACCP(Hazard analysis and critical control points) system, it is necessary to develop of an ontology-based information system that can automatically manage the large amount of HACCP records or information derived from the HACCP operation results. In this paper, we construct a food information ontology which represents the relationships between ingredients, recipe, and features of food categories. Moreover, we develop HACCP automation application adopt the ontology to verify the semantic quality of the designed ontology model by performing HACCP processes such as HACCP diet classification. We expect to contribute to develop a food hygiene information and improve the accuracy of the HACCP data through the semantic system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.11-17
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• 1980

This paper describes realization of digital filter using $\mu$p controler and discusses measured characteristics of this filter, The idea of P. L. implementation[1] is used in realization, and in this system we utilize a DMA and arithmatic control program of $\mu$p. In this way, we can get more flexible capability than the basic PL method, and higher speed than a filter using general purpose $\mu$p in hardware, Furthermore, we get a 15 KHz sampling frequency(fs) as speed limit in real time processing, and know that this limitation is restricted by execution time (58$\mu$ sec) of DMA control statement. As for filter charateristics, maximum stop band frequencies (fsp) are 1665 Hz, 1445 Hz in Butterworth and Tchebichef approximation, respectively, when fs = 14 KHz. Measured errors between the design specification and the actual result are 0.2dB, 0.1 dB in pass band (when cufoff frequency is 500Hz),-1.1dB (when fsp is 1000Hz), 0.4dB(when fsp is 750 Hz) in stop band frequency of Butterworth and Tchebichef, respectively.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.55-67
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• 2005

There are 24 airways in Incehon IFR, including 11 domestic routes and 13 international routes. The airways designated by ministry of Transportation and Construction are the routes for aircraft to fly being serviced by air traffic control system for flight safety. This study reviewed safety situation of existing permanent airways within Incheon IFR and temporary airways connecting North and South Korea. The study tried to identify the problems related to airway operation and to suggest solutions to the questionable area. The main findings are as follows: It is necessary to improve the existing normal airway systems and enlargement of the route. The airway A593 has to be upgraded to normal route. The temporary airways established to connect Seoul and Pyongyang also needs to be upgraded by air traffic control transfer agreement between two Koreas.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.733-744
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• 2000

Due to the randomness of reservoir inflow and supply demand it is not easy to establish an optimal reservoir operation rule. However, the operation rule can be derived by the implicit stochastic optimization approach using synthetic inflow data with some demand satisfied. In this study the optimal reservoir operation which was reasonably formulated as Linear Tracking model for maximizing the hydro-energy of seven reservoirs system in the Han river was performed by use of the optimal control theory. Here the operation model made to satisfy the 2001st year demand in the capital area inputted the synthetic inflow data generated by multi-site Markov model. Based on the regressions and statistic analyses of the optimal operation results, monthly reservoir operation rules were developed with the seasonal probabilities of the reservoir stages. The comparatively larger dams which would have more controllability such as Hwacheon, Soyanggang, and Chungju had better regressions between the storages and outflows. The effectiveness of the rules was verified by the simulation during actually operating period.period.

• Journal of Environmental Health Sciences
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• v.39 no.3
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• pp.268-278
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• 2013

Objectives: The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of seasoned laver products. The hazard analysis examined microbial evaluations and developed a HACCP management plan through the heating process. Methods: In this study we chose three companies and performed the analysis thrice. During this study, general bacteria along with other food poisoning bacteria such as Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, E.coil, O157:H7, Vibrio parahaemolyticus, were studied at varying temperatures from 100 to $300^{\circ}C$. Results: The presence of general bacteria was detected in raw laver in the samples analyzed from all the three companies, and the number ranged from $10^5-10^7$. Bacillus cereus was detected in samples from only two of the three companies analyzed. However, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, E.coil, O157:H7, and Vibrio parahaemolyticus were all negative. General bacteria was reduced to $10^5$ after being subjected to temperatures of $100-250^{\circ}C$, but heating to over $270^{\circ}C$ reduced the number to below $10^3$, and the other microbes such as Bacillus cereus were not detected. Conclusions: In conclusion, the heating process ($270-280^{\circ}C$) along with RPM of 100-1200 were identified as CCP to reduce biological hazards.

• Journal of the Korea Computer Industry Society
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• v.10 no.4
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• pp.143-150
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• 2009

Remote control service, monitoring, gear service of information electronic appliance, various services of security service and so on of Home network that is by link of Ubiquitous environment are offered. These services need verification process through priority test to use and are changed. If test using actuality information electronic device for test, much expenses and time may be invested. Home network test bed offers softness of research using control model and simulator, in this paper, Wish to design and embody home network test bed to do environment construction of home network and test of application service. Because use istent power line just as it is without necessity to establish circuit in addition by solution of home network testbed, expense costs to be less and establishment used easy PLC. Also, propriated Wireless sensor network that use Zigbee by solution of home network testbed. Appliance check and monitor square do by Home Auto that know embodied, and embodied by Home Gateway that interlink terminals of Home Auto and out of.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.9
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• pp.827-832
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• 2010

Many researchers have tried to detect the falling and to reduce the injury associated with falling. Normally the method of detection of a loss of balance is more efficient than that of a compensatory motion in order to predict the falling. The detection algorithm of the loss of balance was composed of three main parts: parts of processing of measured data, construction of an internal model and detection of the loss of balance. The internal model represented a simple dynamic motion balancing with two rear legs of a four-legged chair and was a simplified model of a central nervous system of a person. The internal model was defined by the experimental data obtained within a fixed time interval, and was applied to the detecting algorithm to the end of the experiment without being changed. The balancing motion controlled by the human brain was improved in process of time because of the experience accruing to the brain from controlling sensory organs. In this study a reconstruction method of the internal model was used in order to improve the success rate and the detecting time of the algorithm and was changed with time the same as the brain did. When using the reconstruction method, the success rate and the detecting time were 95 % and 0.729 sec, respectively and those results were improved by about 7.6 % and 0.25 sec in comparison to the results of the paper of Ahmed and Ashton-Miller. The results showed that the proposed reconstruction method of the internal model was efficient to improve the detecting performance of the algorithm.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.2
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• pp.68-75
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• 2009

Up to date, demands for satellite including communication are increasing. Advanced countries on space technology such as America, Russia, Europe, Japan, China and so on already had secured launch vehicle technology which can insert a large class satellite to proper orbit. The introduction of technologies on the large class launch vehicle including propulsion system is difficult due to the utilization possibility for defensive reason. The acquisition of indigenous technical expertise on the design and manufacture of valves is believed to contribute to the successful local development of valves for propulsion systems and to significant improvement of local technical level of valve design and development. This paper introduces current status of valves developed by other countries as well as valves developed in domestic. The Developed technology of valves may underlie the construction of engine control systems required for the reliable operation of the KSLV-II engine system and propulsion system.