• Journal of radiological science and technology
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• v.24 no.2
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• pp.49-52
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• 2001

We compared the characteristics of Siemens virtual wedge device with physical wedges for clinical application. We investigated the characteristics of virtual and physical wedges for various wedge angles (15, 30, 45, and 60) using 6- and 15-MV photon beams. Wedge factors were measured in water using an ion chamber for various field sizes and depths. In case of virtual wedge device, as upper jaw moves during irradiation, wedge angles were estimated by accumulated doses. These measurements were performed at off-axis points perpendicular to the beam central axis in water for a $15\;cm\;{\times}\;20\;cm$ radiation field size at the depth of 10 cm. Surface doses without and with virtual or physical wedges were measured using a parallel plate ion chamber at surface. Field size was $15\;cm\;{\times}\;20\;cm$ and a polystyrene phantom was used. For various field sizes, virtual and physical wedge factors were changed by maximum 2.1% and 3.9%, respectively. For various depths, virtual and physical wedge factors were changed by maximum 1.9% and 2.9%, respectively. No major difference was found between the virtual and physical wedge angles and the difference was within 0.5. Surface dose with physical wedge was reduced by maximum 20% (x-ray beam : 6 MV, wedge angle : 45, SSD : 80 cm) relative to one with virtual wedge or without wedge. Comparison of the characteristics of Siemens virtual wedge device with physical wedges was performed. Depth dependence of virtual wedge factor was smaller than that of physical wedge factor. Virtual and physical wedge factors were nearly independent of field sizes. The accuracy of virtual and physical wedge angles was excellent. Surface dose was found to be reduced using a physical wedge.

• Journal of Intelligence and Information Systems
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• v.11 no.2
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• pp.59-79
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• 2005

Export containers in a container terminal are usually classified into a few weight groups and those belonging to the same group are placed together on a same stack. The reason for this stacking by weight groups is that it becomes easy to have the heavier containers be loaded onto a ship before the lighter ones, which is important for the balancing of the ship. However, since the weight information available at the time of container arrival is only an estimate, those belonging to different weight groups are often stored together on a same stack. This becomes the cause of extra moves, or rehandlings, of containers at the time of loading to fetch out the heavier containers placed under the lighter ones. In this paper, we use machine learning techniques to derive a classifier that can classify the containers into the weight groups with improved accuracy. We also show that a more useful classifier can be derived by applying a cost-sensitive learning technique, for which we introduce a scheme of searching for a good cost matrix. Simulation experiments have shown that our proposed method can reduce about 5$\sim$7% of rehandlings when compared to the traditional weight grouping method.

• Journal of Korea Water Resources Association
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• v.50 no.3
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• pp.201-210
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• 2017

This study proposes a numerical model which is able to simulate turbidity currents intruding into a reservoir and resulting sediment depositions. The proposed model is applied to laboratory experiments by Toniolo and Schultz (2005), and propagation of turbidity currents, morphological change, and trap of suspended sediment are simulated. It is simulated that the turbidity current after plunging at the foreset of the model delta, propagates along the bottom. The thickness of the turbidity current increases significantly after being blocked by the dam, and this effect is propagated in the upstream direction. In addition, it is simulated that the foreset moves in the downstream direction due to both the bedload and suspended load and the thickness of the bottom set increases due to the suspended load. It is found that the height of the intake affects the thickness of the turbidity current and the location of the internal hydraulic jump. The impact of the height of the intake on the trap efficiency is not clear in the experimental results, however, overall trap efficiency is predicted quite successfully by the model. Also, sensitivity analysis is carried out, and the results indicates that the particle size affects the trap efficiency most.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.751-762
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• 1999

In this study, a 1-D laboratory experiment was conducted to investigate the characteristics of transient unsaturated solute transport by using two kinds of soils of which properties were known by test. Especially the TDR method which is proposed in this study was used to measure water content and solute concentration. As results, in the transient flow, the wetting front moves down rapidly, and the distribution of solute concentration near the wetting front showed the similar type of the water content distribution(semi-bell type). A numerical model HYDRUS was used to compare with the experimental results. Numerical results for the water movement are similar to experimental result. However, numerical results of the distribution of solute concentration are more scattered than experimental results. It means that measured dispersivity, numerical dispersion, adsorption coefficient, and soil sample size etc. should be considered in order to determine the dispersivity used in the numerical model. The present measuring method was proved to be superior to other formula and to be an available method to apply to solute transport test. The measuring error of the developed method is estimated smaller than 10% while water content is larger than 0.15.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.396-402
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• 2016

Recently, as the performance of smart phones has advanced and their distribution has increased, various functions in existing devices are accumulated. In particular, functions in smart devices have matured through improvement of diverse sensors. Various applications with the development of smart phones get fleshed out. As a result, services from applications promoting physical activity in users have gotten attention from the public. However, these services are about diet alone, and because these have no exercise motion recognition capability to detect movement in the correct position, the user has difficulty obtaining the benefits of exercise. In this paper, we develop exercise motion-recognition software that can sense the user's motion using a sensor built into a smart phone. In addition, we implement a system to offer exercise with friends who are connected via web server. The exercise motion recognition utilizes a Kalman filter algorithm to correct the user's motion data, and compared to data that exist in sampling, determines whether the user moves in the correct position by using a DTW algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1966-1975
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• 2008

NEMO Basic Support Protocol standardized in IETF provides the seamless communication environment to all nodes within the mobile network regardless of the network movement while the network is moving. According to the standard, when the mobile network moves outside of its home network the network can make use of the binding update message or dynamic routing protocol in order to register the mobility information into the Home Agent(HA). But because these two methods don't consider the route optimization, all packets destined to Mobile Network Nodes(MNNs) attached into the Mobile Router(MR) have to go through HAs of MRs so that they bring on the transmission delay and the waste of the bandwidth. This situation is to be worse and causes the packet fragmentation problem if MRs within the mobile network are nested. Even though there have been some researches about the route optimization to recover the problems, they have problems in the packet transmission performance side. In this paper, we propose a new scheme to improve the network performance by using a dynamic routing protocol and minimizing the number of HAs on the end-to-end path. Various performance evaluations show that the proposed mechanism gives better performance in view of the packet transmission compared to the existing schemes.

• English & American cultural studies
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• v.18 no.4
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• pp.103-137
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• 2018

Harold Pinter's One for the Road(1984) is a play about violence. Nicholas, who appears to be the manager of a place, interrogates Victor, Nicky, and Victor's wife Gila in a room for one day from morning to night. There is no direct physical violence in this play. But hints about the atrocities that took place outside the stage make the audience guess the violence and cruelty. Violence, which is not seen as such, is the central theme of the play. One for the road is worth reading as a resistance to breaking the mirror of global ideology, not as it deals with violent events confined to Turkey. The problem which Pinter had in mind, in particular, is that the United States plays a leading role in producing world-class ideologies, and that Britain is involved in collusion with the United States in cultivating such ideological fantasies, both abroad and at home. This thesis analyzes the contrasting reactions of each character in the play based on this social context. In particular, the conflicting reactions of the characters on the system are the most important conflict in the drama. Nicolas is a manager who moves on the system without seeing the truth. Victor and his family, on the other hand, do not move within the same ideology as Nicholas. This paper will take a look at what their strategies of resistance is and how they are revealed in the work. In fact, Nicholas appears split. Nicholas seemingly reacted decisively to the interpellation of the system. He expresses his belief and respect for the legitimacy of his actions. However, he has repeatedly sought the respect and love of Victor. Nicholas is now swaying. The theme that Nicholas presents consciously by grabbing at his own sway is 'Patriotism.' But this fantasy splits through Victor's silence and death demands. Therefore, the questions to be answered are: So why does Nicolas appear to be torn apart in a system that directs violence? But why is he forced to assimilate into the system? What other figures imply? To answer these questions, this thesis will take Slavoj Zizek's view of ideology. On the other hand, there are previous studies that read the system of violence in One for the road from the Althusser's perspective. Surely, this play explores the role of Ideological State Apparatus. However, from the point of view of Althusser, it is not possible to read Nicholas's division and the point of resistance seen by Victor's family. Pinter does not limit the scope of the ideological system as a closed one that regenerates ideologies, but secures the domain of main body resistance and struggle. On the other hand, there are already several domestic theses that read Pinter's work in Zizek's perspective. But these theses are mainly focused on analysis of Mountain Language. What this thesis would suggest is that there is a potential for an ethical figure of Zizek to be considered in One for the Road.

• (The)Study of the Eastern Classic
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• no.54
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• pp.155-182
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• 2014

This study aimed to find the possibility of interactions between the Doctrine of the Mean and evolutionary biology. Between the two disciplines, there exists a huge gap such as "traditional era vs. modern times" and "humanities vs. natural science." However, this paper assumed that an analysis of their similarities and differences would allow us to find the possibility for them to interact and communicate with each other. For this purpose, the author proposed a three-step approach to studies of the following topics: human nature in step 1, validity of reasons to live in step 2 and biologically affinitive relations in step 3. The present study in step 1 pays attention to the similarities and differences between genes and in-ui-ye-ji (a set of four Confucian values: benevolence, righteousness, propriety and wisdom). This step discusses the issues of ri (principle) and ki (generative force) in Zhu Xi's theory vs. genes and vehicles in evolutionary biology, innate goodness vs. altruism of genes and in-ui-ye-ji vs. epigenetic rules. In step 2, attention is paid to the similarities and differences between natural selection and shi zhong (時中). They are discussed in terms of the upset of the law of nature vs. mutation, changes vs. evolutions and shi zhong vs. natural selection/adaptation. Step 3 focuses on the similarities and differences between species diversity and li-yi-fen-shu (one li and its many aspects). The discussion in this step addresses the issues of part or whole vs. li-yi-fen-shu, biological affinity vs. single energy and ecosystem vs. "the earth moves orderly, and everything thereon flourishes." If these studies are conducted as planned, a new direction can be set for Zhu Xi's neo-Confucianism. Further, the interaction between humanities and natural science will pave the way for us to overcome asymmetry between different disciplines.

• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.575-581
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• 2007

Suaeda japonica is the one of halophyte species which is widely spread in the Ganghwado tidal flat. Halophyte affects to the vertical development of wetland by enhancing the adhesion force of sediments. If demineralization of tidal flat proceeds, the colony of halophyte moves to the seaside where has relatively high salinity content. The change of halophyte zonation can be an environmental indicator to understand the landization of tidal flat. To interpret the spectral characteristics of halophyte, we measured the reflectance of suaeda japonica, reed and sediment around Donggumdo tidal flat in Ganghwado. First and second-derivation analysis was applied to these transformed spectra in order to identify which spectral ranges were distinguished with different coastal wetland vegetation and artificial structures. From the result, red reflectance peak of suaeda japonica were appeared at 600-650nm and greed reflectance peak of reed were appeared at 500-570nm. Spectra of sediments were continuously increased from 350-550nm without any absorption by chlorophyll. These reflectance were easily identified among the spectra of halophyte.

• Korean Journal of Comparative Education
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• v.18 no.4
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• pp.57-81
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• 2008

Comparing to those of the US and European countries, the education for international understanding(EIU) in Korea has a relatively short history. It has been accelerated since Korean government put an emphasis on globalization of the country in 1990s. However, it was not until the beginning of 2000s that academic discussion on EIU has really begun. This study evaluated the development of EIU in Korea and proposed future directions based on its assessment. First of all, EIU in Korea needs to invite more diverse actors beyond UNESCO. Being an interdisciplinary subject, EIU requires more supports from and cooperations among professionals in diverse fields. The main themes in EIU, such as global interdependence, global perspectives, cross-cultural understanding need to be more emphasized, and the global issues such as peace and human rights need to be integrated into the framework of EIU. Based on the analyses of current EIU practices and the forgoing discussions, some recommendations were proposed for the improvement of EIU in Korean schools. In addition, the relationship between EIU and multicultural education was discussed and some suggestions were focused on the ways to improve their cooperation as the world becomes more closer and the Korean society moves into a multicultural society.