• Advances in concrete construction
• /
• v.4 no.3
• /
• pp.173-194
• /
• 2016

This paper consists in a study of a new contructive sequence of road viaducts with Movable Scaffolding System (MSS) using numerical tools based on finite element method (FEM). Traditional and new sequences are being used in Spain to build viaducts with MSS. The new sequence permits an easier construction of one span per week but implies some other issues related to the need of two prestressing stages per span. In order to improve the efficiency of the new sequence by reducing the number of prestressing stages per span, two solutions are suggested in this study. Results show that the best solution is to introduce the 100% of the prestressing force at the self-supporting core in order to improve the road viaduct construction with movable scaffolding system by reducing execution time without increasing economic costs.

• Earthquakes and Structures
• /
• v.17 no.6
• /
• pp.591-598
• /
• 2019

The most recent shaking experiences have demonstrated that the predictions of the seismic models are not always in agreement with the registered responses, especially in the face of extreme earthquakes. Records collected from 1960 to 2011 at a rock-like site are used to develop a neural network that permits to estimate peak ground accelerations via the magnitude, the focal depth, the site-source distance and a seismogenic zone. The neural model is applied to the 8th and 19th September 2017 events that hit Mexican territory and the obtained results show that the network is flexible enough to work appropriately to various conditions of intensity and sites-sources with remarkably predictive capacity. The neural-attenuation curves are compared with those obtained from Ground Motion Prediction Equations and their performance is assessed for events, in addition to the devastating Mexican events, from Japan, Taiwan, Chile and USA.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.549-552
• /
• 2003

In this paper, an efficient architecture of a versatile Reed-Solomon (RS) decoder is designed, where the message length k as well as the block length n can be variable. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm(MEA). A new architecture for the MEA is designed for variable values of error correcting capability t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive and the overclocking technique. The decoder can decode a codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications due to its versatility. A versatile RS decoder over GF(2$^{8}$ ) having the error-correcting capability of up to 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.6
• /
• pp.11-22
• /
• 1996

We address an issue of channel sharing among users by using a random assignment-transmitter-based (RA-T) spread-spectrum transmission scheme which permits the contention mode only in the transmission of a header while avoiding collision during the data packet transmission. Once the header being successfully received, the data packet is ready for reception by switching to one of programmable matched-filters. But the receoption may be blocked due to limited number of matched-filters so that this effect is taken into account in our analysis. For realistic analysis, we integrate detection performance at the physical level with channel activity at the link level through a markov chain model. We also consider an acknowledgement scheme to notify whether the header is correctly detcted and the data packet can be processed continuously, which aims at reducing the interference caused unwanted data transmission. It is shown that receiver complexity can be greatly reduced by choosing a proper number of RA codes at the cost of only a little throughput degradation.

• YAKHAK HOEJI
• /
• v.37 no.5
• /
• pp.532-537
• /
• 1993

Angiogenesis refers to the formation of new capillary blood vessels, or neovascularization occurring under various physical conditions, such as development of the embryo, formation of corpus luteum, wound healing and pathological conditions including tumor growth and metastases, hemangiomas, diabetic retinopathy, rheumatoid arthritis. There are many evidences that angiogenesis is important for the progressive growth of solid tumors and also permits the shedding of metastatic tumors from the primary site. Thus, treatment of angiogenesis inhibitors might be a novel strategy for tumor growth inhibition. Normal vascular endothelial cells are in a state of differentiation and angiogenic endothelial cells migrate and proliferate, and they subsequently differentiate into vessel-forming quiescent phenotype cells, Therfore, it was speculated that a modifier of cell differentiation could also affect angiogenesis. In order to identify new antiangiogenic factors, the research was conducted to estimate the inhibitory activities of cell differentiation agents by means of chick embryo chorioallantoic membrane(CAM) assay. Hence, we have established the CAM assay for the screening of antiangiogenic agents. Using the CAM assay, we found that ursolic acid, a tumor cell differentiation-inducing agent, showed a markedly inhibitory effect on chick embryonic angiogenesis.

• Journal of the Korean Society for Railway
• /
• v.8 no.5
• /
• pp.470-476
• /
• 2005

RCM developed by American air industry in early 1960, its process is most realistic for some physical assets and it permits the system to maintain given function status through decision of demand about optimum maintenance. Therefore, many industries have selected RCM technique and have carried out RCM in order to solve many problems concerning maintenance management as improvement of reliability and availability of facilities, removal of hazard element about break down and retrenchment of maintenance cost. Through the execution of RCM, we can solve actual problems. And finally we will be able to develop more and more maintenance activities with RCM notion. In this study, we will consider the application of KTX-RCM which is set up with basic theory of RCM and constructed to improve vehicle safety, availability and regularity of KTX, linking with CMMS(Computerized Maintenance Management System).

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.410-415
• /
• 2001

Conventional Korean tunnel portals require a lot of overburden as, fer static reasons, about 1.5 to 2.0 times the tunnel diameter is needed for the height in order to achieve a sufficient arching effect. Thus, considerable movement of earth and support constructions are required which lead to undesirably large changes of and damage to the environment. With a massively designed pipe roof, tunnels with little overburden can be built. For the effective construction of a pipe roof as an advancing safeguarding method, the following properties are indispensable： stability, insensitivity to settling and drilling accuracy. With the AT casing system a new pipe roof method has been developed which on the one hand entirely combines the properties mentioned last, and which on the other hand permits safe, economical and environmentally friendly construction of tunnels at low overburden heights of 3 to 6 m.

• Journal of Fisheries and Marine Sciences Education
• /
• v.24 no.2
• /
• pp.311-323
• /
• 2012

For establishment of post-Unification fisheries program, this research has opened a fisheries Act system for South and North Korea and searched a policy direction to make new Fisheries Act for future South and North Korean fisheries program. In addition, North Korea's present fishery industry must be accurately understood and acknowledge in its point of issues in order to develop and improve to rational direction and to overcome the present South and North's fishery industry. As a level to prepare for future unification, reform and reaction of long-termed and well organized South and North's fisheries program must be arranged. Consequently, fishing permits of South and North, licensing system, fisheries resource management system, fisheries adjustment system, foreign fishing regulations system will be compared in this research, and also find an improvement on North Korea's fisheries related act in preparation of future unification.

• Journal of the Korea Society for Simulation
• /
• v.14 no.4
• /
• pp.117-129
• /
• 2005

The climatic change convention is a matter of grave concern to the whole world. As a countermeasure against the climatic change convention, the Korean Government permits the sale of diesel passenger cars since 2005. In this paper, we analyse the effect of the sales permission of diesel passenger car as the countermeasure. The share, carbon emission, and pollutants emission of each type of passenger cars are analysed using system dynamics. The result is that the carbon emission is decreased by $5.5\%$ but the pollutants emission is increased by $5\%$. If the pollutants emission was dealt successfully with, the sales permission of diesel passenger cars would be a good countermeasure against the climatic change convention.

• Hwankyungkyoyuk
• /
• v.14 no.1
• /
• pp.127-144
• /
• 2001

This paper presents an analysis of the Teaching and Learning for a Sustainable Future (TLSF) program, an innovative teacher education and regular professional development by the United Nations Educational, Scientific and Cultural Organization (UNESCO) employing the curriculum analysis framework created by Posner. Using this framework the analyst found that the TLSF design is based on good research in regard to learning, teaching, and assessment now driving efforts to reform environmental teacher education. Ongoing development of the TLSF program in the research setting of an international level permits ever deeper connection with emerging curriculum theory and curriculum practice and allows new linkage as ideas are tested in research classrooms.