• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.1-18
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• 2007

This study is about an arrangement method of trapezoidal pre-cast segment lining that can be applied in shield tunnel construction. Trapezoidal segment lining is formed by assembling tapered pre-cast concrete segments taking advantage of the tapered shape of pre-cast segments upon delivery on site. By calculating tapering of the segments manufactured in single type and rotating the segments when putting them together, a variety of tunnel alignments can be arranged in the most efficient way. Once the design criteria and tunnel alignment (straight or curved) is analyzed, the sequence of assembling trapezoidal segments in compliance with tunnel alignment will be computed. On site an operator can utilize the softwareto automatically determine sequential arrangement of trapezoidal segments. When the actual arrangement of segmental lining is different from the computed output, the operator can input the actually measured values to coincide the computerized calculation with the real status of assembly. Then the adjustment will be the basis of subsequent arrangement of segments, thus the continuity of work can be guaranteed.

• Korean Journal of Adult Nursing
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• v.17 no.5
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• pp.697-708
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• 2005

Purpose: This study was to develop, implement, and evaluate an e-learning education program for improving practical knowledge and preventing nursing errors and adverse events of nurses working in the operating room (OR). Method: The e-learning program was developed and evaluated according to the following processes: 1) preparation phase 2) implementation phase 3) evaluation phase. In evaluation phase, the effectiveness was analyzed based on the Kirkpatrick's model. Results: The e-learning program consisted of OR basic nursing skills and techniques and nursing activities' manual based on the categories of nursing errors: surgical operation preparation, nursing skills and techniques, environment management, patient safety and comfort, and patient monitoring. The program was provided through on-line, http://cafe.daum.net/pnuhorn, for 4 weeks. The mean score(percent) of participants' satisfaction was $21.24{\pm}1.71$(68.2%). Their total knowledge level was significantly improved(Z=-3.00, p=.003) and specifically in the category of environment management(Z=-3.77, p<.001) and patient monitoring(Z=-2.46, p=.014). The occurrence of nursing errors or adverse events was a little decreased, but not statistically significant(Z=-3.10, p=.756). Conclusion: E-learning for nurses is one way of effective and efficient teaching-learning strategies. For better e-learning, it is important to develop the vital content of the education and objective measures for detecting nursing errors and adverse events.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1115-1120
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• 2003

The recent tendency in the automobile industries is toward light weighting vehicle body to improve the problems by environmental pollution as well as improving fuel cost. The effective way to reduce the weight of vehicle body seems to be application of new materials for body structure and such trend is remarkable. Among the various materials for vehicle body, stainless steel sheet (for example, 301L and 304L), TRIP steel and cold rolled steel sheets are under the interests. However, in order to guarantee reliability of new material and to establish the long life design criteria of body structure, it is important and require condition to assess spot weldability of them and fatigue strength of spot welded lap joints which were fabricated under optimized spot welding condition. And, recently, a new issue in the design of the spot welded structure is to predict economically fatigue design criterion without additional fatigue tests. In general, for fatigue design of the spot-welded thin sheet structure, additional fatigue tests according to the welding condition, material, joint type, and fatigue loading condition are generally required. This indicates that much cost and time for it should be consumed. Therefore, in this paper, the maximum stresses at nugget edge of spot weld were calculated through nonlinear finite element analysis first. And next, obtained the ${\Delta}P-N_{f}$ relation through the actual fatigue tests on spot welded lap joints of similar and dissimilar high strength steel sheets. And then, the ${\Delta}P-N_{f}$ relation was rearranged in the ${\Delta}{\sigma}-N_{f}$ relation. From this ${\Delta}{\sigma}-N_{f}$ relation, developed the fatigue design technology for spot welded lap joints of them welded using the optimized welding conditions.

• Journal of the Society of Disaster Information
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• v.10 no.3
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• pp.396-407
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• 2014

In 19th May 2014, the government announced that KCG(Korea Coast Guard) is dissolved regarding responsibility for recently accident which is Sewol ferry disaster. But KCG, a central administrative agency is responsible for protecting maritime sovereignty of South Korea; the most basic and indispensable organization. Furthermore, The purpose of KCG is to provide the safety of the public and keeping of public order by prescribing matters necessary for the securement of maritime security, maintenance of public order and protection of marine resources & facilities. Therefore, In this article, I would like to suggest tentatively named FRAMEWORK ACT ON KOREA COAST GUARD's management plan which could reflect the scope of functions. It means we examine the current state of KCG, and would like to signpost for the most ideal way of legal system in Korea Coast Guard. Finally, this treatise is expected that this research can be a guideline contribute to improving Korea Coast Guard relevant laws even a little.

• Tunnel and Underground Space
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• v.22 no.6
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• pp.449-461
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• 2012

Coal ash generated from thermal power plants is planned to use for mine filling in order to prevent subsidence of the ground. In according, the basic physical properties and flow characteristics were grasped using coal ash from generated Yeongdong thermal power plant, and hydraulic filling experiments were performed a total of eight times by manufacturing the model of 1 inclined shaft in Hanbo coal mine. The specific gravity of coal ash is 2.34, and the result of particle size analysis belongs to silty sand (SM). Coal ash of weight ratio of 60% was used in the filling experiments of the model, since liquefaction have shown in coal ash less than weight ratio of 70% from the result of slump and flow test. The outlet should be located at the bottom of the inclined and vertical shaft, this was favorable way in improving the filling efficiency from the experiment results regardless of groundwater exists.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.4
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• pp.447-458
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• 2009

Energy loss at manholes, often exceeding friction loss of pipes under surcharged flow, is considered as one of the major causes of inundation in urban areas. Therefore, it is necessary to analyze head loss at manholes, especially in case of surcharged flow. Hydraulic experiments were conducted with three cases. Case A is to test whether the shapes of the manholes influence head loss coefficients. Case B and C were proposed to further reduce head losses by improving the manhole hydraulic efficiency. In case B, the joining part of the pipe at both shapes of manholes is shifted from central part to side part. The test in case C is to check the average head loss coefficient by installing the side benching in square manhole, based on shifted joining part model. The average head loss coefficient for circular and square manhole on case A was 1.6. This did not show much difference of the head loss coefficients in spite of the discharge variation in this case. However, case B and C show large difference between head loss coefficients due to the strong oscillation of water surface and the horizontal swirl motion. The circular and square manholes in case B reduced the head loss by 30% and 6% than ones in case A, respectively. The average head loss coefficient for circular manhole in case B was 1.1. Case C reduced average loss coefficients of the square manhole in case A from 1.6 to 1.1. Accordingly, the circular manhole in case B and the square manhole in case C showed the effective way to reduce the head loss. These head loss coefficients could be available to apply to the urban sewer system with surcharged flow.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7C
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• pp.598-603
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• 2010

In this paper, we work for Lipreading using visual information for ship environment. Lipreading is studied for using image information including lips of a speaker at the existing speech recognition system. This technique is a compensation method to increase recognition rate decreasing remarkably in noisy circumstances. Proposed way improved the rate of recognition improving methode of preprocessing using the Gabor Filter for Ship Environment. The experiment were carried out under changing of light with time in the ship environment with lip image. For Comparing with recognition, make a compare with between method of lip region of interest (ROI) before Gabor filtering and after Gabor filtering. In the case of using method of lip ROI before Gabor filtering, the result of the experiments applying to the proposed ways recognition resulting in 44% of recognition.

• Smart Structures and Systems
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• v.18 no.1
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• pp.53-74
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• 2016

This paper presents an experimental study on constructing a tunable secondary suspension for high-speed trains using magneto-rheological fluid dampers (referred to as MR dampers hereafter), in the interest of improving lateral ride comfort. Two types of MR dampers (type-A and type-B) with different control ranges are designed and fabricated. The developed dampers are incorporated into a secondary suspension of a full-scale high-speed train carriage for rolling-vibration tests. The integrated rail vehicle runs at a series of speeds from 40 to 380 km/h and with different current inputs to the MR dampers. The dynamic performance of the two suspension systems and the ride comfort rating of the rail vehicle are evaluated using the accelerations measured during the tests. In this way, the effectiveness of the developed MR dampers for attenuating vibration is assessed. The type-A MR dampers function like a stiffness component, rather than an energy dissipative device, during the tests with different running speeds. While, the type-B MR dampers exhibit significant damping and high current input to the dampers may adversely affect the ride comfort. As part of an ongoing investigation on devising an effective MR secondary suspension for lateral vibration suppression, this preliminary study provides an insight into dynamic behavior of high-speed train secondary suspensions and unique full-scale experimental data for optimal design of MR dampers suitable for high-speed rail applications.

• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.997-1004
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• 2013

There is imminent need to find a way to measure the recreational benefits of water so that appropriate actions can be taken to make a multi-purpose reservoir. Therefore, this study attempts to apply a choice experiment to quantifying the recreational benefits of a multi-purpose reservoir, using a specific case study of Sangkwan multi-purpose reservoir. We consider the trade-offs between price and attributes of recreational attributes for selecting a preferred alternative and derive the marginal willingness to pay (MWTP) estimate for each attribute. The results show that the MWTP for providing additional 10,000 ton of water is estimated to be 3 won per household per year. The MWTP for improving 1 level of water quality is computed to be 645.5 won per household per year. Moreover, the MWTP for providing recreation facilities is calculated to be 1,518.6 won per household per year. This study allows us to provide policy-makers with useful quantitative information that can reduce uncertainty in the decision-making process related to a multi-purpose reservoir construction projects.

• Journal of Korean Elementary Science Education
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• v.39 no.3
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• pp.323-337
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• 2020

To achieve effective learning, knowledge must be shared and developed through interaction with peer learners. Therefore, science education emphasizes small group inquiry activities that solves tasks through the interaction of members. The effect of small group inquiry activities depends on how to compose small groups. The way in which a group is composed is a very important factor for improving interaction. In particular, it has been reported that the gender of peer is a very important factor in the interaction between students in the composition of small groups. Meanwhile, studies are being conducted on the types and stability of verbal interactions in small group inquiry activities using social network analysis. The purpose of this study is to analyze the types and stability of verbal interaction types and stability according to gender-grouping in elementary school students' small group activities using social network analysis. To this end, 60 5th graders in elementary school were conducted with different gender in the composition of the group of male, female and mixed-gender students. The study found that the composition of a group by gender had little impact on the type or stability of verbal interaction. However, the frequency of verbal interactions was higher in mixed-gender groups than in other groups. Through this process, the gender-grouping in elementary school students' small group activities suggests a mixed-gender group.