• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권12호
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• pp.601-605
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• 2006

The resistance-capacitance (RC) delay of signals through interconnection materials becomes a big hurdle for high speed operation of semiconductors which contain multi-layer interconnections in smaller scales with higher integration density. Low-k materials are applied to the inter-metal dielectric (IMD) materials in order to overcome the RC delay. Relaxation continuum (RCT) model that includes neutral-species transport model have developed to model the etching process in a capacitively coupled plasma (CCP) device. We present the parametric study of the modeling results of a two-frequency capacitively coupled plasma (2f-CCP) with $N_2/H_2$ gas mixture that is known as promising one for organic low-k materials etching. For the etching of low-k materials by $N_2/H_2$ plasma, N and H atoms have a big influence on the materials. Moreover the distributions of excited neutral species influence the plasma density and profile. We include the neutral transport model as well as plasma one in the calculation. The plasma and neutrals are calculated self-consistently by iterating the simulation of both species till a spatio-temporal steady state profile could be obtained.

• 정보기술과데이타베이스저널
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• 제7권1호
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• pp.99-111
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• 2000

The aim of this study is to find the key elements for the successful introduction of a Cyber University (CU) in Korea. Since information technology (IT) has dramatically changed our lives it is inevitable for education to follow suit. The old education system was based on the following principle, of a teacher physically interacting with his or her pupils at a school. However, this is set to become infinitely more flexible with the freedom of choice given to the pupil who are now able to adopt, beyond barriers of time and space what, and how they study. All this will be made possible with the use of IT. The essentials for the CU would be a positive and flexible education paradigm, also able to satisfy students with a totally new system of education that replaces physical interaction with virtual interaction. Another point that needs to be taken into account is the number of potential students, their expectations and needs. And any national or international restrictions need to be addressed. One major hurdle for the acceptance of a CU in Korea is the vast difference between its conservative culture and directness of Western culture. Despite this, it will soon become imperative for Korea that she embraces the rapidly changing attitudes and requirements in order for the survival of the nation and an individual.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.605-612
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• 2011

As the power grids are integrated into one big umbrella called a "smart grid," communication protocol plays a key role in successful operations. The successful deployment of smart grid interoperability is a major hurdle that must be overcome. The micro grid, a small power system that distributes energy resource, is operated in diverse regions. Different vendors use different communication protocols in the operation of the micro grid. Recently, the IEC 61850 has been legislated to solve the interoperability problems in power utility automation. The present paper presents a micro grid system based on the IEC 61850 protocol. It consists of a micro grid monitoring system, a protocol converter that transforms serial data to IEC 61850 data, and distributed energy resource controllers for diverse DER nodes. A developed communication gateway can be deployed for DER controllers with serial links to exchange data with IEC 61850-based devices. The gateway can be extended to IEC 61850-based distribution automation systems, substation automation systems, or SCADA.

• 한국발생생물학회지:발생과생식
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• 제23권2호
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• pp.79-92
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• 2019

Humanized mice, containing engrafted human cells and tissues, are emerging as an important in vivo platform for studying human diseases. Since the development of Nod scid gamma (NSG) mice bearing mutations in the IL-2 receptor gamma chain, many investigators have used NSG mice engrafted with human hematopoietic stem cells (HSCs) to generate functional human immune systems in vivo, results in high efficacy of human cell engraftment. The development of NSG mice has allowed significant advances to be made in studies on several human diseases, including cancer and graft-versus-host-disease (GVHD), and in regenerative medicine. Based on the human HSC transplantation, organ transplantation including thymus and liver in the renal capsule has been performed. Also, immune reconstruction of cells, of the lymphoid as well as myeloid lineages, has been partly accomplished. However, crosstalk between pluripotent stem cell derived therapeutic cells with human leukocyte antigen (HLA) mis/matched types and immune CD3 T cells have not been fully addressed. To overcome this hurdle, human major histocompatibility complex (MHC) molecules, not mouse MHC molecules, are required to generate functional T cells in a humanized mouse model. Here, we briefly summarize characteristics of the humanized mouse model, focusing on development of CD3 T cells with MHC molecules. We also highlight the necessity of the humanized mouse model for the treatment of various human diseases.

• 세라미스트
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• 제21권4호
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• pp.331-348
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• 2018

With the expectation to overcome the problem of increasing energy consumption, polymer electrolyte membrane fuel cells are getting more attention as a promising environmentally friendly and sustainable next-generation energy conversion system. In spite of the rapid improvement of polymer electrolyte membrane fuel cells(PEMFCs), there are several critical issues still need to be resolved for practical commercialization. Out of the many issues, the main hurdle comes from oxygen reduction reaction(ORR), thus development of efficient ORR electrocatalysts is the main key for enhancing PEMFC performance. Among various catalysts, 1D nanostructured catalyst is a promising candidate because it holds many advantages that come from nanostructuring while supplementing the disadvantages of other nanostructures such as nanoparticles(0D) or gyroids(3D). This review focused on diverse 1D nanostructures and talks about their advantages as catalyst for ORR. Different 1D nanostructures will be introduced while applying the structures to different materials system showing the prospects of 1D nanostructures for improving PEMFC.

• Parasites, Hosts and Diseases
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• 제56권6호
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• pp.545-552
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• 2018

Plasmodium vivax is more challenging to control and eliminate than P. falciparum due to its more asymptomatic infections with low parasite densities making diagnosis more difficult, in addition to its unique biological characteristics. The potential re-introduction of incidence cases, either through borders or via human migrations, is another major hurdle to sustained control and elimination. The Republic of Korea has experienced re-emergence of vivax malaria in 1993 but is one of the 32 malaria-eliminating countries to-date. Despite achieving successful nationwide control and elimination of vivax malaria, the evolutionary characteristics of vivax malaria isolates in the Republic of Korea have not been fully understood. In this review, we present an overview of the genetic variability of such isolates to increase understanding of the epidemiology, diversity, and dynamics of vivax populations in the Republic of Korea.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.281-287
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• 2021

Bioinformatics is formed with a blend of biology and informatics technologies and it employs the statistical methods and approaches for attending the concerning issues in the domains of nutrition, medical research and towards reviewing the living environment. The ceaseless growth of DNA sequencing technologies has resulted in the production of voluminous genomic data especially the DNA sequences thus calling out for increased storage and bandwidth. As of now, the bioinformatics confronts the major hurdle of management, interpretation and accurately preserving of this hefty information. Compression tends to be a beacon of hope towards resolving the aforementioned issues. Keeping the storage efficiently, a methodology has been recommended which for attending the same. In addition, there is introduction of a competent algorithm that aids in exact matching of small pattern. The DNA representation sequence is then implemented subsequently for determining 2 bases to 6 bases matching with the remaining input sequence. This process involves transforming of DNA sequence into an ASCII symbols in the first level and compress by using LZ77 compression method in the second level and after that form the grid variables with size 3 to hold the 100 characters. In the third level of compression, the compressed output is in the grid variables. Hence, the proposed algorithm S_Pattern DNA gives an average better compression ratio of 93% when compared to the existing compression algorithms for the datasets from the UCI repository.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1217-1230
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• 2021

Using a multinomial logit model with the panel-data set of Vietnam manufacturing firms, this paper investigates the impacts of foreign direct investment (FDI) - small and medium enterprises (SMEs) linkages and other factors on SMEs' participation in the global value chain (GVC). We consider GVC firms are those engaging in any of the three modes including (i) using domestic inputs to export (D2E), (ii) using imported inputs to produce for the domestic market (I2P), (iii) using imported inputs to export (I2E). We discover that FDI-SME linkages statistically encourage Vietnamese SMEs to integrate into the GVC via I2P and I2E, while no statistical association between FDI-SME linkage and D2E participation is found. GVCs participation likelihood is also positively correlated with the introduction of new product introduction. The establishment of firms' production facilities in industrial zones and foreign ownership are both reported to be significantly decisive factors to SMEs' decisions on GVC participation. Besides, there is a strong association between firms' attributes, i.e. employment, capital intensity as well as financial access, and their participation in the GVC. Local governance quality (proxied by the Provincial Competitiveness Index) and the share of skilled labor at the province-level can facilitate firms' integration into GVCs, while greater market concentration may be a hurdle to such potential.

• Current Photovoltaic Research
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• 제9권2호
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• pp.23-30
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• 2021

Perovskite solar cells (PSCs) are currently attracting attention as a promising source of photovoltaic power generation for their rapid increase in efficiency within a short research period. However, the 2-step deposition method, which has been considered as a proper film fabrication route in commercialization point of view of PSC, requires a complicated control of environment to achieve high efficiency because each step of the process are affected by humidity in different manner. It is clearly a large hurdle for this technic to be transferred to industrialization. In this study, we developed a simple surface treatment by which high quality perovskite films can be fabricated through 2-step deposition method in a relatively wide humidity range without complicated humidity control at each step.

• 식품과학과 산업
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• 제49권2호
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• pp.34-44
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• 2016

Given that fermented foods, such as kimchi and doenjang, are main food sources for high sodium intake in Korea, there have been needs to develop sodium-reduced kimchi and doenjang with the proper quality. However, small and medium sized business could not actively develop the sodium-reduced products due to lack of techniques and information as well as economical reasons. The most important aspects is to address food safety issues including microbial contaminations in sodium-reduced foods. Hurdle Technology, physical, biological, chemical control technique, would have to be preferentially considered to increase the hygiene safety standards in entire processing steps including raw materials, process water, manufacturing environments, and so on. Once the food hygiene level is stable, the next challenges are to improve the taste of the sodium reduced-products as well as to packaging and storage technologies. The development of a variety of sodium-reduced fermented foods would result in significant mitigation of sodium intake by Korean. This report provides the directions to develop sodium-reduced kimchi, doenjang or pickled food products for small and medium sized business, based on the technical consulting results of sodium reduction project supported by Ministry of Food and Drug Safety in 2015.