• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1556-1570
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• 2016

In the process of virtual inertia control (VIC), the frequency regulation capability of the directly-driven wind turbine with permanent-magnet synchronous generator (D-PMSG) on wind farm is related to its rotor kinetic energy and capacity margin. This paper proposes the method for assessing the D-PMSG frequency regulation capability and defining its coefficient according to the operating state of wind power generators. In addition, the calculating method of parameters in VIC is also discussed according to the principles of primary frequency regulation and inertia response of synchronous generators. Then, by introducing the capability coefficient into the proportion-differential virtual inertia control (PD-VIC) for power coordination, a coordinated virtual inertia control (C-VIC) strategy is developed, with the consideration of the difference in frequency regulation capability between wind power generators. The proposed control method can not only give full play to the frequency regulation capability of wind power generators, decrease the movements of the pitch angle control system but also bring some self-coordination capability to different wind power generators thus to avoid a secondary drop in system frequency. The simulations and experiments prove the proposed method to be effective and practicable.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.400.1-400.1
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• 2016

Interfacial engineering approaches as an efficient strategy for improving the power conversion efficiencies (PCEs) of inverted polymer solar cells (iPSCs) has attracted considerable attention. Recently, polymer surface modifiers, such as poly(ethyleneimine) (PEI) and polyethylenimine ethoxylated (PEIE), were introduced to produce low WF electrodes and were reported to have good electron selectivity for inverted polymer solar cells (iPSCs) without an n-type metal oxide layer. To obtain more efficient solar cells, quantum dots (QDs) are used as effective sensitizers across a broad spectral range from visible to near IR. Additionally, they have the ability to efficiently generate multiple excitons from a single photon via a process called carrier multiplication (CM) or multiple exciton generation (MEG). However, in general, it is very difficult to prepare a bilayer structure with an organic layer and a QD interlayer through a solution process, because most solvents can dissolve and destroy the organic layer and QD interlayer. To present a more effective strategy for surpassing the limitations of traditional methods, we studied and fabricated the highly efficient iPSCs with mono-layered QDs as an effective multi-functional layer, to enhance the quantum yield caused by various effects of QDs monolayer. The mono-layered QDs play the multi-functional role as surface modifier, sub-photosensitizer and electron transport layer. Using this effective approach, we achieve the highest conversion efficiency of ~10.3% resulting from improved interfacial properties and efficient charge transfer, which is verified by various analysis tools.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.75-79
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• 1999

Geo-features play a key role in object-oriented or feature-based geo-processing system. So the strategy for how-to-model and how-to-manage the geo-features builds the main architecture of the entire system and also supports the efficiency and functionality of the system. Unlike the conventional 2D geo-processing system, geo-features in 3B GIS have lots to be considered to model regarding the efficient manipulation and analysis and visualization. When the system is running on the Web, it should also be considered that how to leverage the level of detail and the level of automation of modeling in addition to the support for client side data interoperability. We built a set of 3D geo-features, and each geo-feature contains a set of aspatial data and 3D geo-primitives. The 3D geo-primitives contain the fundamental modeling data such as the height of building and the burial depth of gas pipeline. We separated the additional modeling data on the geometry and appearance of the model from the fundamental modeling data to make the table in database more concise and to allow the users more freedom to represent the geo-object. To get the users to build and exchange their own data, we devised a file format called VGFF 2.0 which stands for Virtual GIS File Format. It is to describe the three dimensional geo-information in XML(eXtensible Markup Language). The DTD(Document Type Definition) of VGFF 2.0 is parsed using the DOM(Document Object Model). We also developed the authoring tools for. users can make their own 3D geo-features and model and save the data to VGFF 2.0 format. We are now expecting the VGFF 2.0 evolve to the 3D version of SVG(Scalable Vector Graphics) especially for 3D GIS on the Web.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.1100-1116
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• 2014

The purpose of this study is to investigate how children use the PAIR strategy for their audiences in the writing on the screen and how the comments play a role to communicate between an author and audiences. In order to perform this research, 7 elementary school students(4th-6th grade) participated in the literary education program designed to promote to write on the screen. As a result, 42 body texts(635 sentences) and 424 comments of children's writing on the screen were collected and analyzed according to the PAIR strategies and performance behaviour. The findings are as follows: first, 'attracting' is used the most among PAIR strategies and second, the most frequent performance behavior of comment is 'expression'. These findings indicate that children's writing strategy considering audiences tends to be emotionally appealing and performance behavior of comment is likely to focus on affective expression.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1019-1022
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• 2016

Background: Diagnostic difficulties in hematological malignancies may lead to unacceptably prolonged help-seeking to diagnostic interval as well as increased complications and poor outcomes. Proactive consultation by a clinical pathologist (PCCP) may help clinical diagnosis and therapeutic strategy. Hence, the aim of this investigation was to evaluate the effect of PCCP on the help-seeking to diagnostic interval in hematological cancer cases. Materials and Methods: From January to November, 2015, abnormal results of hematological laboratory testing with added laboratory comment were selectively screened out, and patients with such abnormalities in hematological laboratory testing and accompanied laboratory comment with PCCP were enrolled. Results: A total of 125 aberrant results of hematological laboratory testing were given with accompanied laboratory comments with PCCP and 40.8% (n=51) of these patient-oriented comments had an effect on clinical diagnosis and therapeutic strategy. Twelve of the subjects belonged to newly diagnosed hematological malignancies with the assistance of PCCP, and the help-seeking to diagnostic interval was also shortened from 42 days to 26 days in chronic lymphoid leukemia (CLL), from 83 days to 11 days in multiple myeloma (MM), and from 128 days to 15 days in myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN). During the monitoring interval, neither complication events nor deaths were reported in the study group. Conclusions: It was seemingly that PCCP prevented diagnostic delay in hematological malignancies via shortening the help-seeking to diagnostic interval, particularly in CLL, MM and MDS/MPN cases. PCCP can be considered to play an essential role in prompt establishment of diagnosis in hematological malignancies for those who newly present.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.42.4-43
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• 2018

Most galaxies are believed to evolve through mergers and accretions. In particular, minor mergers and gas accretion appear to play an important role in galaxy evolution in the present-day Universe. Tidally-disrupted debris from such processes remain as diffuse, low-surface brightness structures because the dynamical timescale in the outskirts is significantly longer than that in the central regions. Although these structures will give us useful insight into the mass assembly history of galaxies, it is difficult to detect them due to their faint surface brightness. In order to investigate the structural properties of outskirts in nearby galaxies, we conduct deep and wide-field imaging survey with KMTNet. We present our observing strategy and an optimal data reduction process to recover faint extended features in the images of KMTNet. Using the imaging data of NGC 1291 obtained from KMTNet, we find that a peak-to-peak sky gradient can be reduced less than 0.4-0.6% of the original sky level in the entire image. We also find that we can reach the surface brightness of ${\mu}_{(B,1{\sigma})}$ ~ 29.5, ${\mu}_{(R,1{\sigma})}$ ~ 28.5 mag $arcsec^{-2}$ in one-dimensional profile, that is mainly limited by the uncertainty in the sky determination. It indicates that deep imaging data of KMTNet is suitable to study the extended faint features of nearby galaxies, such as stellar halos, outer disks, and dwarf companions.

• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.586-603
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• 2012

This study is a survey conducted to explore what art high school students specifically see as nature of science. Third-year students of a high school of arts in Gyeonggi-do participated in the survey. The questionnaire was classified into three categories - the formative arts in the fine arts, the sound arts in music, the performing arts in dance, and drama and play. The study analyzed what they think of as similar aspects of science and art respectively according to their majors, with focus on the extracts. As a result, they mentioned 'creative imagination', 'correlation with technology', 'social and cultural relation', 'subjectivity', 'variability', and 'inquiring attitude' as similarities between science and art. The results are almost the same as the elements of the nature of science as agreed on by scientists. From the result, we can assume that students majoring in art, indeed, need an education on the nature of science. Also, while the fine arts students have more tendency to perceive inquiring attitude than others, music students are more likely to perceive variability than others. Therefore, teaching strategy in experimental inquiring context for the former is more helpful in understanding the nature of science, and teaching strategy in the context of scientific history for the latter.

• The Journal of Korean Medicine
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• v.30 no.5
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• pp.127-136
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• 2009

Objective: This study aimed to analyze the current status of treatments and patients with diabetic peripheral neuropathy, and then map out of a strategy for development of generalized-treatments for diabetic peripheral neuropathy in Traditional Korean Medicine. Methods: We selected research materials from various databases such as PubMed, Google, KStudy, KoreanTK, OIM, KOMS and books. Also, to understand current tendencies of medical examination and treatment related with diabetic peripheral neuropathy, we requested Health Insurance Review and Assessment Service clinical data from 2003 to 2007. Results: It is reported that the incidence of diabetic peripheral neuropathy is increasing in an aging society. The medical fees of National Health Insurance related with diabetic peripheral neuropathy show a year-on-year increase. There are no particularly effective therapies for diabetic peripheral neuropathy in Western medicine, and in some papers, it was reported that treatment of diabetic peripheral neuropathy using Traditional Korean Medicine was effective. However, patients usually visit on Western medical center rather than seek Traditional Korean Medicine. To take charge of clinical fields related with diabetic peripheral neuropathy by Traditional Korean Medicine, we need more studies and experiments of diabetic peripheral neuropathy using Traditional Korean Medicine and should make a standardized protocol. Conclusion: Various studies related with diabetic peripheral neuropathy using Traditional Korean Medicine will have to be undertaken hereafter. We expect that Traditional Korean Medicine will play a vital role in treating of diabetic peripheral neuropathy.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.4
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• pp.13-30
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• 2008

We explore the determinants of long-term relationship between the buyer and the supplier to help suppliers develope a strategy to build long-term relationship with their buyers. Based upon an extensive literature review, we propose three droops of independent variables which may affect long-term relationship, including (a) environmental factors (product complexity, product importance, source dependence, price sensitivity), (b) relational factors(trust, commitment, satisfaction, intention of expansion), (c) operational performance(quality, delivery, cost capability, technical knowhow). The buyer's actual period of relationship with its main supplier is used as a dependent variable. Using hierarchical multiple regression analysis, we empirically test hypotheses, analysing a sample of 290 manufacturing firms in the U.S. The statistical results indicate that the buyer's source dependence, price sensitivity and the supplier's commitment play a significant role in establishing long-term relationship between the buyer and the supplier. However, the supplier's cost capability and technical knowhow in operational performance negatively affect long-term relationship in contrast with our hypotheses. Due to this controversial result, we divide the sample group Into dual sourcing and multiple sourcing environments and reconduct regression analysis in a post hoc manner. The findings show that the supplier's cost capability and technical knowhow are negatively associated with the length of relationship only in the multiple sourcing environment. The results may confirm that both parties' opportunistic behavior is more salient in the multiple sourcing environment than in the single sourcing environment.

• Journal of Information Science Theory and Practice
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• v.1 no.3
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• pp.60-73
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• 2013

The Database Industry Promotion Act was proposed at the National Assembly plenary session on July 26, 2012 and since then it has been in the process of enactment in consultation with all the governmental departments concerned. The recent trend of economic globalization and smart device innovation suggests a new opportunity and challenges for all industries. The database industry is also facing a new phase in an era of smart innovation. Korea is in a moment of opportunity to take an innovative approach to promoting the database industry. Korea should set up a national policy to promote the database industry for citizens, government, and research institutions, as well as enterprises. Above all, the Database Industry Promotion Act could play a great role in promoting the social infrastructure to enhance the capacity of small and medium-sized enterprises. This article discusses the background of the development of the Database Industry Promotion Act and its legislative processes in order to clarify its legal characteristics, including the meaning of the act. In addition, this article explains individual items related to the overall structure of the Database Industry Promotion Act. Finally, this article reviews the economic effects of the database industry for now and the future.