• Journal of Internet Computing and Services
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• 제10권5호
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• pp.41-47
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• 2009

Routing through a backbone, which is responsible for performing and managing multipoint communication, reduces the communication overhead and overall energy consumption in wireless sensor networks. However, the backbone nodes will need extra functionality and therefore consume more energy compared to the other nodes. The power consumption imbalance among sensor nodes may cause a network partition and failures where the transmission from some sensors to the sink node could be blocked. Hence optimal construction of the backbone is one of the pivotal problems in sensor network applications and can drastically affect the network's communication energy dissipation. In this paper a distributed algorithm is proposed to generate backbone trees through robust multi-hop clusters in wireless sensor networks. The main objective is to form a properly designed backbone through multi-hop clusters by considering energy level and degree of each node. Our improved cluster head selection method ensures that energy is consumed evenly among the nodes in the network, thereby increasing the network lifetime. Comprehensive computer simulations have indicated that the newly proposed scheme gives approximately 10.36% and 24.05% improvements in the performances related to the residual energy level and the degree of the cluster heads respectively and also prolongs the network lifetime.

• Journal of Information Management
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• 제40권4호
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• pp.1-22
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• 2009

Large-scaled information extraction plays an important role in advanced information retrieval as well as question answering and summarization. Information extraction can be defined as a process of converting unstructured documents into formalized, tabular information, which consists of named-entity recognition, terminology extraction, coreference resolution and relation extraction. Since all the elementary technologies have been studied independently so far, it is not trivial to integrate all the necessary processes of information extraction due to the diversity of their input/output formation approaches and operating environments. As a result, it is difficult to handle scientific documents to extract both named-entities and technical terms at once. In this study, we define scientific as a set of 10 types of named entities and technical terminologies in a biomedical domain. in order to automatically extract these entities from scientific documents at once, we develop a framework for scientific core entity extraction which embraces all the pivotal language processors, named-entity recognizer, co-reference resolver and terminology extractor. Each module of the integrated system has been evaluated with various corpus as well as KEEC 2009. The system will be utilized for various information service areas such as information retrieval, question-answering(Q&A), document indexing, dictionary construction, and so on.

• Fire Science and Engineering
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• 제20권2호
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• pp.31-43
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• 2006

In Korea, the Emergency Medical Service, EMS is provided by Fire Services with 119 EMS and all the public uses the service for free. Although it appears very successful and is respected nationally, structural problem EMS exist and are worsening. First of all, the "free riding effect" becomes increasingly problematic. Some argue that 30% of the demands is not urgent or emergent. The total number of demands is increasing even without the free riding effect. The Current EMS system itself cannot meet the increasing EMS demand. The medical aspect is so poor that the EMS cannot dispatch a medical specialist to the scene. The cardiac arrest resuscitation rate is only $1.24{\sim}9.9%$, compared to 40% in Boston, MA, USA. But due to the regulations and limitations of the Fire Service organization, it is difficult to secure enough EMS resources. To work out these problems, it needs a structural innovation. To secure enough resources and achieve higher medical performance we should invite the medical sector and the private sector into EMS arena by contracting partnerships with Fire Services and charging a reasonable EMS fee. We found through statistical test that any partnership system is more effective than fire-alone system and most countries around the world have partnership system rather than fire-alone system.

• The Journal of the Korea Contents Association
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• 제12권2호
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• pp.40-51
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• 2012

Recently, many users discuss and argue with others using replying comments. This implies that a series of comments can be a new source of information since various opinions can be appeared in the dispute. It is important to understand the implicit dispute structure immanent in the comment set. In this paper, we examine the characteristics of disputes using replying comments in the Internet forum sites using a set of test articles with the comments collected from SketicalLeft and Agora, which are famous Internet forum sites in Korea. And we propose a new method for detecting and visualizing the dispute sections and relations from a large set of replying comments. To show the performance of our method, we measured precision, recall, and F-measure. According to the experimental results, the F-measures of the detection of the comments in dispute are about 0.84 (SketpcialLeft) and 0.83 (Agora); those of the detection of the commenter pairs in dispute are 0.75 (SketpcialLeft) and 0.82 (Agora), respectively. Since our method exploits the temporal order of commenters to detect the disputes, it is not dependent on the host language nor on the typos in comments. Also, our method can help the readers to grasp the structure of controversy hidden in the comment set through the visualized view.

• Journal of the Korean GEO-environmental Society
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• 제13권10호
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• pp.77-83
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• 2012

Recently, excavations using propped walls were popularized in downtown due to reduced settlement of nearby structures. These excavations is induced strain to propped walls or settlement in near ground. In this study, the ground reinforcing effect was proven using NDS, which is an inorganic injection material. Injection tests were performed to compute optimum injection pressure and volume. Next, calibration chamber tests were performed by using computed injection pressure and volume, and wall behaviour was examined for overburden pressures of 50kPa and 150kPa. Ground reinforcing effect was shown when the material behind the propped wall was grouted. From test results, optimum injection pressure was 350kPa and the optimum volume was 10L considering economics. Calibration chamber test results show that after the material was grouted, the maximum settlement was reduced to 19% of the non-grouted condition. For overburden pressures of 50kPa and 150kPa behind the wall, the settlement of the wall increased by 58% and 57% when compared to the case of no overburden pressure.

• Korean Journal of Social Welfare
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• 제35권
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• pp.427-451
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• 1998

The purpose of this study is (1) to contrast the welfare state formation in Korea with that in Western European nations, and (2) to examine the historical peculiarities of the Korean welfare state formation process. For the analysis, this study uses' contrast of context' logic of comparative history and contrast the process of (1)modern state formation (2) civil society development (3) interventionist state evolution of Korea with those of Western European nations. The findings of this study are as follows: First, the distingushing role of nation state as welfare provider is very different. It is attributed to the difference in the traditional dominance structure and in the nation-bulding process of each case. Second, class cleavage of the Western Eeuropean nations has been continually mobilized for political action and converted into political resources, while it is impossible to achieve such results in Korea which has continued labor excusive regime. Third, the institutionalization patterns of welfare politics are different. In Western Eeuropean nations, public welfare benefits have been able to produce welfare coalitions and politics of solidarity. By contrast, since welfare have been thoroughly depoliticized and informalized in Korea, voters and political parties have not been able to make issues of welfare problem Due to these historical peculiarities, it seems to be impossible that Korea's underdeveloped public welfare could be changeable in near future.

• Applied Microscopy
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• 제34권1호
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• pp.13-21
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• 2004

The high voltage electron microscope (HVEM) newly installed in KBSI is an advanced transmission electron microscope capable of atomic resolution (${\leq}1.2{\AA}$ point-to-point resolution) together with high titling function (${\pm}60^{\circ}$), which are suitable to do 3-dimensional atomic imaging of a specimen. In addition, the instrument can be controlled by remote operation system, named as 'FasTEM' for the HVEM, which is favorable to overcome some environmental obstacles resulting from the direct operation. The FasTEM remote operation system has been established between the headquarter of KBSI in Daejeon and the Seoul branch. The server system in the headquarter has been connected with a portable client console system in the Seoul branch using an advanced internet resource, 'KOREN' of 155 Mbps grade. Most of the HVEM functions essential to do remote operation are available on the portable client console. The experiment to acquire the high resolution image of [001] Au has been achieved by excellent transmission of control signals and communication with the HVEM. Real-time reaction like direct operation, such as controls of the illumination and projection parameters, acquisition and adjustment of each detector signal, and electrical steering of each motor-driven system has been realized in remote site. It is positively anticipated that the first remote operation of HVEM in conjunction with IT infraengineering plays a important role in constructing the network based e-Science Grid in Korea for national user s facilities.

• Clean Technology
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• 제2권1호
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• pp.32-43
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• 1996

The interactions of the societal-industrial system with the environment form one of the most critical issues in today's world. The inadequacy of current environmental regulatory structures and of traditional ways of analyzing environmental issues, together with the continuing need to mitigate the environmental perturbations arising from this complex relationship, have led to the development of a new conceptual framework termed industrial ecology. Industrial ecology (IE), defined by Graedel and Allenby, is the means by which humanity can deliberately and rationally approach and maintain a desirable carrying capacity, given continued economic, cultural and technological evolution. The concept requires that an industrial system be viewed not in isolation from its surrounding systems, but in concert with them. IE is a systems view in which one seeks to optimize the total materials cycle from virgin material, to finished material, to component, to product, to obsolete product, and to ultimate disposal. Factors to be optimized include resources, energy, and capital. In the present paper, the concept of Industrial Ecology and its application through efficient and practical Design for Environment (DFE) methodologies and tools will be introduced to Korea. This paper will also emphasis on the industrial environment within which DFE methodologies must be used, including the fundamentals of industrial design activities, concurrent engineering, constraints on design choices and existing technological infrastructure.

• Journal of Life Science
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• 제25권3호
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• pp.269-275
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• 2015

Collagen peptides, which are found at high concentrations in the human body, are present in animal bones and the skin of marine organisms, namely, fish scales. Collagen is the most abundant structural protein of various connective tissues in animals. Furthermore, it is widely used in biomedical material, pharmaceutical, cosmetic, food, and leather industries. Peptides extracted from scales of various fish protect against ultraviolet B (UVB)-induced skin damage and photo-aging. However, the protective effects of collagen peptides derived from the scales of Branchiostegus japonicus against UVB exposure are unclear. This study investigated the effects of peptides larger than 1 kDa (high-molecular weight peptides [HMP]) and smaller than 1 kDa (low-molecular weight peptides [LMP]), derived from extracts of B. japonicus scales, against UVB-induced skin damage and photo-aging. These peptides scavenged 1,1-diphenyl-2-picrylhydrazyl radicals in a dose-dependent manner. In UVB-exposed HaCaT human keratinocytes, LMP inhibited 8-isoprostane generation, a marker of cellular lipid peroxidation. The peptides also suppressed the UVB-induced increase in tyrosinase activity and melanin content in B16F10 mouse melanoma cells. In addition, the LMP and HMP treatment suppressed UVB-induced elastase and matrix metalloproteinase-1 activities in the HaCaT cells. These results indicate that peptides derived from B. japonicus scales have antioxidant, antiphoto-aging, and skin-whitening effects.

• The Korean Journal of Financial Management
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• 제22권1호
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• pp.1-36
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• 2005

In this study, we analyzed determinant factors of leverage ratio and debt maturity for Korean firms in the simultaneous equation system using 2SLS (two stage least square) method under assumption that two variables are jointly determined in the capital structure decision. As a result of the analysis, we found that leverage ratio and debt maturity are positively related. Also, as for determinant factors of debt maturity, agency cost hypothesis, asset maturity matching hypothesis, signalling and liquidity risk hypothesis are all generally supported, and further leverage ratio are significantly positively related with firm size, but negatively related with default risk. However, when we divided samples into groups according to bank debt level and Chaebul affiliation, with contrast to existing study which worked on similar issues with OLS, we found no evidence supporting the argument that the information asymmetry problem is less severe in firms with more bank debt, whereas information asymmetry and financial constraint problems are more severe in non-Chaebul affiliated firms.