• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.401-412
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• 2020

This study analyzed the causes of warehouse fires using a creative problem-solving technique called TRIZ. It identified preventive measures by applying 4M. The results are as follows. First, this study examined the inconsistency among the causes of warehouse fires using TRIZ. Second, it analyzed human factors and fire prevention measures in warehouses such as safety standards for managers, and methods for the promotion of safety consciousness among workers, and for the reinforcement of construction technology for sandwich panel workers. Third, it identified the mechanical and facility factors and fire prevention measures in warehouses such as safety facilities, the expanded installation of safety devices, the adoption and development of fire suppression equipment, and the deployment of methods to improve the fire resistance of sandwich panels. Fourth, it presented working and environmental factors and fire prevention measures in warehouses such as the tightening of safety precautions and the supervision of working methods, and setting fire partitions both in loading places and based on performance-based design. Finally, it proposed managerial factors and fire prevention measures in warehouses such as specific targeting for firefighting with low fire hazards, reviewing the material quality regulations of non-combustible or higher for sandwich panels in the specific target of firefighting that cannot apply fire safety standards, installing sprinklers in cold storage, and mandating the installation of automated facilities with retroactive application regardless of the floor area in the warehouse with a sandwich panel structure.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.79-84
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• 2014

To investigate the plating properties of a diethylene glycol-based Ag immersion plating solution containing citric acid, silver immersion plating was performed in a range from room temperature to $50^{\circ}C$ using sputtered Cu specimens. The used Cu specimens possessed surface structure with large numbers of pinholes which were created with over-acid etching. The Ag immersion plating performed at $40^{\circ}C$ exhibited that the pinholes and copper surface were completely filled with Ag just after 5 min mainly due to galvanic displacement reaction, indicating the best plating properties. Subsequently, the surface morphology of Ag-coated Cu became rougher as the plating time increased to 30 min because of the deposition of silver nanoparticles created by chemical reduction in the solution. The specimen that its overall surface was covered with silver indicated the start of oxidation at temperature higher than around $50^{\circ}C$ in air as compared with pure Cu, indicating enhanced anti-oxidation properties.

• Korean Journal of Optics and Photonics
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• v.5 no.3
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• pp.423-430
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• 1994

We designed and fabricated the single mode fiber pigtailed DFB-LD module for 2.5 Gbps optical communication system. In the design of the DFB-LD module, we made the module divided into two parts of inner sub-module and outer 14-pin butterfly package and cylindrical shaped sub-module contain quasi confocal 2 lens system including optical isolator and electrical connection between these parts via hybrid substrate of bias T circuit. Laser welding was used to assemble the sub-module which requires accurate fixing between optical elements. The fabricated DFB-LD module showed optical coupling efficiency of 20% and - 3 dB small signal response of more than 2.6 GHz. We confirmed mechanical reliability of the module by temperature cycle test where the tested module exhibit optical power fluctuation of less than 10%. Finally we evaluated the performance of the fabricated DFB-LD module as light source of 2.5 Gbps optical communication system, sensitivity of - 30.2 dBm was obtained through 47 km optical fiber transmission under the criterion of $1\times10^{-10}$ BER and transmission penalties were 1.5 dB caused by extinction ratio and 1.0 dB caused by chromatic dispersion of normal single mode fiber. fiber.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.180-190
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• 2013

The purpose of this study was to determine the optimal amount of 2 ingredients, i.e., black barley flour ($X_1$), and olive oil ($X_2$), for the production of white pan bread from black barley flour. The experiment was designed according to the central composite design of response surface methodology, which showed 10 experimental points, including 2 replicates for black barley flour and olive oil. Significant differences were found in the results of the physical and mechanical properties analysis of each sample, including weight (p<0.05), volume (p<0.01), specific loaf volume (p<0.01), color L (p<0.01), color a (p<0.001), color b (p<0.05), hardness (p<0.001), springiness (p<0.01), cohesiveness (p<0.01), gumminess (p<0.001) and chewiness (p<0.05). Significant differences in the sensory measurements were observed in color (p<0.01), appearance (p<0.01), texture (p<0.05), taste (p<0.05) and overall quality (p<0.05). The optimum formulation, which was calculated using the numerical and graphical methods, was determined to be 18.00% black barley flour and 1.80% olive oil.

• Tunnel and Underground Space
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• v.25 no.1
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• pp.97-106
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• 2015

We must precisely investigate the mechanical characters of rock to design rock slope safely and efficiently. But the method of clinometer has some disadvantages. So, we need a new measurement that can replace the method of clinometer. In this study, we analyze the reliability of joint orientation measurements in rock slope using the 3D laser scanner and program Split-FX that is a point cloud data analysis software. We could acquire the 495 pieces joint data through the automatic extraction of features. And we confirmed that there were some errors occurred with ${\pm}4^{\circ}$ of dip and ${\pm}5^{\circ}$ of dip direction. Generally, the method of clinometer has ${\pm}5^{\circ}$ and ${\pm}10^{\circ}$ error ranges of the joint orientation(dip/dip direction) that are the results of the advance research. Therefore, we analyzed the method of 3D laser scanner, and it is found to be efficient, reliable. This method is expected to mend the disadvantages of Clinometer method.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.159-167
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• 2014

PURPOSES : The purpose of this study is to analyze the requirements of the road traffic safety moderator robot when road repairing. The road traffic safety moderator robot is road traffic safety equipment and to conversions mechanical engineering and IT when road repairing. METHODS : The study used AHP based on the survey from road repair related expert that field engineers, design engineers, public officials and professors. The survey used paired comparison. The survey items were safety, convenience and economics. The safety is classified as visibility or efficiency, the convenience is classified as utility or mobility and the economics is classified as initial investment cost or maintenance $ management cost. The survey alternatives were the road traffic safety moderator robot, traffic regulation by human, traffic regulation by mannequin and traffic signs. The software for AHP is Expert Choice 2000. RESULTS : The results of AHP analyze, the weighted value of safety was analyzed with the highest at 0.488 of survey items. The weighted value of convenience was analyzed at 0.295, the weighted value of economics was analyzed at 0.218. The results of the road traffic safety moderator robot, the weight value of efficiency and utility were analyzed with the highest at 0.284 and 0.259 of alternatives. The weighted value of initial investment cost and maintenance & management cost were analyzed with the lowest at 0.203 and 0.211 of alternatives. The consistency test results of each items, null hypothesis is rejected because the CR values were 0.000 respectively. Therefore, the study results are consistency. CONCLUSIONS : The result of this study, overall value of the road traffic safety moderator robot came off second-best of other alternatives. The road traffic safety moderator robot has been received highest praise by the result of the study as good road traffic safety equipment when road repairing because the weighted values of efficiency and utility were analyzed with the highest of survey items. The efficiency mean securing safety and the utility mean practical assistance when road repairing. The results of this study showed that the road traffic safety moderator robot will effective for traffic safety when road repairing. economics and visibility are that supplementation of the road traffic safety moderator robot because the weighted values of economics and visibility were analyzed with the lowest of survey items. The consistency test results are consistency because the CR values were 0.000 respectively.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.497-508
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• 2013

This paper introduces a numerical model which can evaluate the fire-resistant capacity of reinforced concrete members. On the basis of the transient heat transfer considering the heat conduction, convection and radiation, time-dependent temperature distribution across a section is determined. A layered fiber section method is adopted to consider non-linear material properties depending on the temperature and varying with the position of a fiber. Furthermore, effects of non-mechanical strains of each fiber like thermal expansion, transient strain and creep strain are reflected on the non-linear structural analysis to take into account the extreme temperature variation induced by the fire. Analysis results by the numerical model are compared with experimental data from the standard fire tests to validate an exactness of the introduced numerical model. Also, time-dependent changes in the resisting capacities of reinforced concrete members exposed to fire are investigated through the analyses and, the resisting capacities evaluated are compared with those determined by the design code.

• Journal of the Korean Institute of Gas
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• v.18 no.2
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• pp.73-80
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• 2014

The objective of this paper is to assess the service life and retrain methods of specimens, which were subjected to carbonation attack, obtained from mix proportion of Sam-cheok LNG storage tank under construction. As the results, accelerated-carbonation penetration depths of 7, 28, 56 ages indicated 4.45, 9.19, 13.37mm, and even considering for cover depths of steel of LNG storage tank under real operation, it was enough. In addition, with carbonation velocity coefficient calculated by carbonation penetration depths, the service life to design cover depth(70, 80, 90, 100mm) of PC outer tank of LNG storage tank was 779, 1017, 1287, 1589 years and 466, 609, 771, 951 years, respectively, considering the $CO_2$ concentration in air which account for the 0.03% and 0.05%. Also, the restrain methods to carbonation attack were feasible through controlling the factors affecting the changes of hydration products such as $Ca(OH)_2$, ion composition in pore solution and matter mobility of organization structures within hardened concrete.

• Journal of the Korean GEO-environmental Society
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• v.19 no.9
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• pp.5-12
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• 2018

The foundation of the multi-span greenhouse structures is designed with small shallow concrete foundation considering mainly the vertical load. However, recently, due to an abnormal climate such as strong wind, horizontal load and up-lift load over design strength are applied to the foundation, causing safety problems of the greenhouse foundation. In order to reasonably evaluate the safety of greenhouse foundations, rotational and pullout stiffness expressed by the ground-foundation interaction should be evaluated, which also affects the safety of the upper structural members. In this study, three representative basic foundation types were selected by classifying greenhouse standards in Korea according to the shape, and the horizontal loading tests and theoretical calculation were performed for each foundation type. As a result of the comparison and analysis of the test and calculation, it was found that rotational resistance of the foundation is different according to the ratio of the contact area between the foundation and ground when the conditions of the foundation - ground contact surface and the mechanical properties of the ground are the same.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.487-496
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• 2020

For the purpose of next generation technology for robot perfomances, a RAoRA (Robot Actor on Robot Arm) structure was proposed using a robot arm joined with a humanoid robot actor. Mechanical analysis, machine design and fabrication were performed for motions combined with the robot arm and the humanoid robot actor. Kinematical analysis for 3D model, spline interpolation of positions, motion control algorithm and control devices were developed for movements of the robot actor. Preliminary visualization, simulation tools and integrated operation of consoles were constructed for the non-professionals to produce intuitive and safe contents. Air walk was applied to test the developed platform. The air walk is a natural walk close to a floor or slow ascension to the air. The RAoRA also executed a performance with 5 minute-running time. Finally, the proposed platform of robot performance presented intensive and live motions which was impossible in conventional robot performances.