• Geomechanics and Engineering
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• v.9 no.6
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• pp.757-774
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• 2015

Reinforcing soils with the geosynthetics have been shown to be an effective method for improving the uplift capacity of granular soils. The pull-out resistance of the reinforcing elements is one of the most notable factors in increasing the uplift capacity. In this paper, a new reinforcing element including the elements (anchors) attached to the ordinary geogrid for increasing the pull-out resistance of the reinforcement, is used. Thus, the reinforcement consists of the geogrid and anchors with the cylindrical plastic elements attached to it, namely grid-anchors. A three-dimensional numerical study, employing the commercial finite difference software FLAC-3D, was performed to investigate the uplift capacity of the pipelines buried in sand reinforced with this system. The models were used to investigate the effect of the pipe diameter, burial depth, soil density, number of the reinforcement layers, width of the reinforcement layer, and the stiffness of geogrid and anchors on the uplift resistance of the sandy soils. The outcomes reveal that, due to a developed longer failure surface, inclusion of grid-anchor system in a soil deposit outstandingly increases the uplift capacity. Compared to the multilayer reinforcement, the single layer reinforcement was more effective in enhancing the uplift capacity. Moreover, the efficiency of the reinforcement layer inclusion for uplift resistance in loose sand is higher than dense sand. Besides, the efficiency of reinforcement layer inclusion for uplift resistance in lower embedment ratios is higher. In addition, by increasing the pipe diameter, the efficiency of the reinforcement layer inclusion will be lower. Results demonstrate that, for the pipes with an outer diameter of 50 mm, the grid-anchor system of reinforcing can increase the uplift capacity 2.18 times greater than that for an ordinary geogrid and 3.20 times greater than that for non-reinforced sand.

• Steel and Composite Structures
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• v.38 no.1
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• pp.87-102
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• 2021

To investigate the failure form, bending stiffness, and residual bearing capacity of monolithic composite beams with laminated slab throughout the fire process, fire tests of four monolithic composite beams with laminated slab were performed under constant load and temperature increase. Different factors such as post-pouring layer thickness, lap length of the prefabricated bottom slab, and stud spacing were considered in the fire test. The test results demonstrate that, under the same fire time and external load, the post-pouring layer thickness and stud spacing are important parameters that affect the fire resistance of monolithic composite beams with laminated slab. Similarly, the post-pouring layer thickness and stud spacing are the predominant factors affecting the bending stiffness of monolithic composite beams with laminated slab after fire exposure. The failure forms of monolithic composite beams with laminated slab after the fire are approximately the same as those at room temperature. In both cases, the beams underwent bending failure. However, after exposure to the high-temperature fire, cracks appeared earlier in the monolithic composite beams with laminated slab, and both the residual bearing capacity and bending stiffness were reduced by varying degrees. In this test, the bending bearing capacity and ductility of monolithic composite beams with laminated slab after fire exposure were reduced by 23.3% and 55.4%, respectively, compared with those tested at room temperature. Calculation methods for the residual bearing capacity and bending stiffness of monolithic composite beams with laminated slab in and after the fire are proposed, which demonstrated good accuracy.

• Advanced Industrial SCIence
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• v.2 no.2
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• pp.25-30
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• 2023

The purpose of this study is to empirically analyze the impact of corporate innovation activities on corporate innovation performance using data from companies participating in the smart farm project. A company's innovation activities were divided into planning capacity, R&D capacity, and commercialization capacity, and the impact of each innovation activity on the company's sales and patent creation was estimated. The moderating effect was also analyzed. Regression analysis was conducted as a research method, and as a result of the analysis, it was found that planning capacity, R&D capacity, and commercialization capacity related to innovation within a company have an impact on corporate performance creation. appeared to be In order to increase the business performance of technology commercialization, it was confirmed that planning and R&D capabilities as well as governmental technology policy support are needed.

• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.118-133
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• 2024

The sapwood portion of fast-growing teak is mostly ignored due to its inferior quality. One of the possibilities for utilizing sapwood waste is to convert it into activated carbon that has good adsorption capabilities. The raw materials used in this research were sapwood of 14-year-old fast-growing teak sapwood (FTS) waste, which was taken from three trees from community forests in Wonosari, Gunungkidul, Yogyakarta Special Region. FTS waste was taken from the bottom of the tree up to a height of 1.3 m. The activation process is conducted with an activation temperature of 750℃, 850℃, and 950℃. The heating duration consists of three variations: 30 min, 60 min, and 90 min. The quality evaluation parameters of activated carbon include yield, moisture content, volatile matter content, ash content, fixed carbon content, adsorption capacity of benzene, adsorption capacity of methylene blue, and adsorption capacity of iodine. The results showed that the activated carbon produced had the following quality parameters: yield of 75.61%; moisture content of 1.27%; volatile matter content of 9.98%; ash content of 5.43%; fixed carbon content of 84.58%; benzene absorption capacity of 8.58%; methylene blue absorption capacity of 87.73 mg/g; and iodine adsorption capacity of 948.19 mg/g. It can be concluded that activated carbon from FTS waste has good iodine adsorption, which fulfilled the SNI 06-3730-1995 quality standard. Due to the iodine adsorption ability of FTS waste activated carbon, the conversion of FTS waste to activated carbon is categorized as a potential method to increase the value of this material.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.7
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• pp.1263-1269
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• 2009

Stable and sustainable power supply means maintaining a certain level of power quality and service while securing energy resource and resolving environmental issues. Distributed generation (DG) has become an essential and indispensable element from environmental and energy security perspectives. It is known that voltage violation is the most important constraint for load variation and the maximum allowable DG. In distribution system, sending voltage from distribution substation is regulated by ULTC (Under Load Tap Changer) designed to maintain a predetermined voltage level. ULTC is controlled by LDC (Line Drop Compensation) method compensating line voltage drop for a varying load, and the sending voltage of ULTC calls for LDC parameters. The consequence is that the feasible LDC parameters considering variation of load and DG output are necessary. In this paper, we design each LDC parameters determining the sending voltage that can satisfy voltage level, decrease ULTC tap movement numbers, or increase DG introduction. Moreover, the maximum installable DG capacity based on each LDC parameters is estimated.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1526-1531
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• 2007

Data transmission capacity that is required in 2010 is forecasted that increase by optical communication capacity more than present centuple, and is doing increased demand of optical communication related industry product present. Specially, Lid glass' application that is one of optical communication parts is used in optical communication parts manufacture of Fiber array, Ferrule array, Fanout Black, Silica optical waveguide chip and splitter etc. Also, it is used widely for communication network system, CATV, ATM-PON, FTTH and system. But, Lid glass need much processing times and becomes cause in rising prices of optical communication parts because production cost is expensive. The objectives, of this work is to suggest the micro concave and convex pattern manufacturing technology on borosilicate plate using high temperature and compression molding method. As a result, could developed micro pattern Mold more than 5 pattern, and reduce Lid Glass manufacture cycle time.

• Structural Engineering and Mechanics
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• v.66 no.4
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• pp.439-444
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• 2018

This paper presents a numerical study on the behavior of continuous hollow steel beam strengthened using carbon fiber reinforced polymers (CFRP). Most previous studies on the CFRP strengthening of steel beams have been carried out on the steel beams with simple boundary conditions. No independent study, to the researcher's knowledge, has studied on the CFRP strengthening of square hollow section (SHS) continuous steel beam. However, this study explored the effect of the use of adhesively bonded CFRP flexible sheets on the behavior of the continuous SHS steel beams. Finite Element Method (FEM) has been employed for modeling. Eleven specimens, ten of which were strengthened using CFRP sheets, were analyzed under different coverage length, the number of layers, and the location of CFRP composite. ANSYS software was used to analyze the SHS steel beams. The results showed that the coverage length, the number of layers, and the location of CFRP composite are effective in increasing the ultimate load capacity of the continuous SHS steel beams. Application of CFRP composite also caused the ductility increase some strengthened specimens.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.105-113
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• 2011

The study about three-phase synthetic making test using DC power has been performed in order to increase the making test capacity on Vacuum Circuit Breaker. And, it made possible to solve the limitations that short-circuit testing facilities can not fulfill the testing requirements of VCB exceeding three-phase 36[kV] 31.5[kA]. By using DC power and high speed spark-gap switch, this method made the equivalence with the pre-arc that occurred during the making process under the fault condition of power system. As results, KERI(Korea Electrotechnology Research Institute) could have capacity to carry out type test for VCB under three-phase 52[kV] 40[kV], which satisfies the IEC Standard.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.72-77
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• 2011

Dynamic Line Rating (DLR) techniques have been greatly worthy of notice for efficiently increasing transmission capacity as well as controlling load-flow in overhead transmission lines, in comparison with the existing power system operating with Static Line Rating (SLR). This paper describes an utilization method to implement DLR control system for old transmission lines built in the first stage using the ground clearance design standard with lower dips. The suggested DLR system is focused on designing as temperature control system rather than current/load control system. Based on several performance for conductor temperatures, it is shown that DLR system with efficiency can be implemented.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.5
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• pp.55-64
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• 1996

This paper presents performance evaluation of a new high speed inter-processor communication(HIPC) network for large capacity and high performance digitral switching system. The HIPC structure implements the fast reservation and concurrent arbitration technique (modified round-robin arbitration). The performance evaluation of HIPC was performed by not only computer simulation but also numerical approximation method which was derived for a single server multi-queue system with nonexhaustive cyclic service. The approximation results are almost same with that of computer simulation. The TDX-10 basic callscenario was applied to the HIPC netowrk and analyzed. these results were compared with TDX-10 IPC and shows that the difference of th emean waiting time in the TX buffer of NTP node increases sharply according to the increase of the message arrival rate.