• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.51-60
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• 2004

DAB(Digital Audio Broadcasting) is a new media service that can provide CD quality audio, various data service, interactive and high quality mobile communications through popular media such as terrestrial broadcasting, satellite, cable TV, and internet. In this paper, a new EPG(Electronic Program Guide) application model is proposed. The model is based on DAB and combines a DAB receiver and PCs so that it can take advantages of using various multimedia services and plenty of internet contents. The developed EPSD(EPG Provider System on DAB) has Web-based Server/Client structure and povides EPG functionalities to client PCs over internet. Therefore, the DAB receiver can be smaller and cheaper, and can develop abundant data services on internet. It can also provide high quality video services and be expected to become an important component in future home network systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.774-781
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• 2014

The radar measurements are composed of range, Doppler and angles which are expressed as polar-coordinate components. An approach to match the measurements with the states of target dynamics which are modeled in cartesian coordinates is to use the pseudo-measurements or the extended Kalman filter in order to solve the mismatching problem. Another approach is that the states of dynamics are modeled in polar coordinates and measurement equation is linear. However, this approach bears that we have to deal with a time-varying dynamics. In this study, it is proposed that the states of dynamics are expressed as polar-coordinate component and the system matrix of the dynamic equation is modeled as a time-invariant. Nonlinear terms that appear due to the proposed modeling are regarded as a system input. The results of a series of simulation runs indicate that the tracking filter that uses the proposed modeling is viable from the fact that the Doppler measurement is easy to be augmented in the measurement equation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.286-297
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• 2017

This paper is a study of 6~18 GHz wideband high power amplifier which is composed of 10 single amplifier and coaxial type spatial power combiner. The property of this spatial power combiner is on a similar principle to antipodal antenna radiation mechanism. Therefore, the key structure of proposed spatial power combiner is the antipodal finline PCB board and the finline curve shape is numerically synthesized by using Klopfensein's optimum impedance taper. The measured CW output power of spatial combined high power amplifier is nearly 50 W. In conclusion we prove the good combining performance between the spatial power combiner and 10 single amplifier over 6~18 GHz frequency ranges. Also, we developed the key component PA and MFC MMIC which controls the phase and gain of the each amplifier, The main characteristic of MFC MMIC is to maximize combining efficiency of power amplifier.

• Journal of the Korean earth science society
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• v.38 no.5
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• pp.378-392
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• 2017

Teacher quality is a topic of international concern, as it impacts student learning and teacher preparation. This study compared the undergraduate secondary science teacher preparation programs from two universities in Korea with those of Oregon, USA. We examined the programs' structural curricular coherence, conceptual curricular coherence, and curricular balance. Structural curricular coherence was determined by examining the overarching goals of the institutions' programs, the organization of the programs of study in terms of meeting those goals, and outside bodies of evidence. All universities were in structural coherence for various reasons. Conceptual curricular coherence was determined by examining students' perceptions of the connection between their preparation and their clinical practice. In case of Korea, most students from both universities were not satisfied with their practical preparation. In the US, the students from both institutions felt well prepared to transition to inservice teaching. To determine curricular balance, we examined the institutions' preparation programs looking at the credit hours taken in the four main areas of the teacher knowledge base: GPK (General Pedagogical Knowledge), SMK (Subject Matter Knowledge), PCK (Pedagogical Content Knowledge), and CK (Contextual Knowledge). The total credit hours taken in each category was very similar by country but the application and field component in the USA was far greater than those of Korea where the focus was heavily on SMK and PCK. The main reason for these may be the nations' licensing and employment processes.

• Journal of the Korean housing association
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• v.19 no.3
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• pp.95-104
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• 2008

The purpose of this study is systematically to examine the changes that have taken place to the community spaces of apartment complexes in the national capital region of Korea. The methodology used in this study entails analyzing existing research and case studies carried out on this subject matter. Prior to these case studies, an existing study had been made of the chronological changes in policy, related laws and regulations in Korea since the 1960s. This case study presents the component ratio and systematized present situation of community spaces in twenty-two apartment complexes. An analysis of the researching process has revealed the following important factors related to the changes that have occurred in community spaces in apartment complexes. (1) Apartment complexes were originally developed in the 1960s to ease the housing shortage. Because the priority was to solve the housing shortage, community spaces were not widely considered or developed. (2) The standard of community spaces was established as mandatory by law in the 1970s, resulting in the emergence of various facilities that provided community spaces. (3) In the 1980s, various design competitions for apartment complexes were conducted as an attempt to improve residential environments. This process resulted in the development of new characteristic of subsidiary facilities. (4) During the period when housing problems were being addressed in the 1990s, the Community Service Center was added to the welfare facilities for residents. (5) Recently, during the 2000s, an improvement in residential environments has evolved due to the expansion of housing supply and economic growth. The quality of community spaces has therefore improved from the 1960s onward. This study revealed that policy and related laws regarding community space in Korea have been developing in a suitable direction and that the addition of various facilities to community spaces has improved the quality of living environments.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.2
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• pp.134-142
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• 2012

A bipolar plate is a major component of a fuel cell stack, which occupies 50~60% of the total weight and over 50% of the total cost of a typical fuel cell stack. In this study, a composite bipolar plate is designed and fabricated to develop a compact and light-weight direct methanol fuel cell (DMFC) stack for a small-scale Unmanned Aerial Vehicle (UAV) application. The composite bipolar plates for DMFCs are prepared by a compression molding method using resole type phenol resin as a binder and natural graphite and carbon black as a conductor filler and tested in terms of electrical conductivity, mechanical strength and hydrogen permeability. The flexural strength of 63 MPa and the in-plane electrical conductivities of 191 S $cm^{-1}$ are achieved under the optimum bipolar plate composition of phenol : 18%; natural graphite : 82%; carbon black : 3%, indicating that the composite bipolar plates exhibit sufficient mechanical strength, electrical conductivity and hydrogen permeability to be applied in a DMFC stack. A DMFC with the composite bipolar plate is tested and shows a similar cell performance with a conventional DMFC with graphite-based bipolar plate.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.213-218
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• 2017

The purpose of this study was to develop age-biomass model in Chungnam region containing random effect. To develop the biomass model by species and tree component, data for Pinus densiflora in central region is collected to 30 plots (150 trees). The mixed model were used to fixed effect in the age-biomass relation for Pinus densiflora, with random effect representing correlation of survey area were obtained. To verify the evaluation of the model for random effect, the akaike information criterion (abbreviated as, AIC) was used to calculate the variance-covariance matrix, and residual of repeated data. The estimated variance-covariance matrix, and residual were -1.0022, 0.6240, respectively. The model with random effect (AIC=377.2) has low AIC value, comparison with other study relating to random effects. It is for this reason that random effect associated with categorical data were used in the data fitting process, the model can be calibrated to fit the Chungnam region by obtaining measurements. Therefore, the results of this study could be useful method for developing biomass model using random effects by region.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5205-5210
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• 2015

Background: Acute leukaemia is characterized by fast growth of abnormal clones of haemopoietic precursor cells inside bone marrow leading to undue accumulation in the bone marrow. Acute lymphoblastic leukemia (ALL) is the most common form of childhood cancer. Materials and Methods: The study concerned 50 children diagnosed with ALL (mean age, $8.55{\pm}2.54$) compared to 40 healthy controls (mean age, $8.00{\pm}1.85$). The Hb, serum copper, ceruloplasmin oxidase, advanced oxidation protein products (AOPPs), total antioxidant activity (TAA) and protein were measured in all groups.One proteinous component was isolated by gel filtration chromatography from the precipitate produced by polyethylene glycol. Results: Significantly higher levels of AOPP, copper and decrease in total antioxidant activity were noted in the cases. Statistical analysis also showed a significant increase (p<0.01) in the activity of serum ceruloplasmin oxidase in patients with ALL compared to normal subjects .The maximum velocity (Vmax) and Michaelis constant had values of 104.2 U/L and 11.7 mM, respectively. The ${\Delta}H^*$ values for ceruloplasmin oxidase in ALL patients were positive, confirming the reaction to be endothermic. Conclusions: The results from this study showed a significant increase in AOPP, ceruloplasmine oxidase and decrease in total antioxidant activity .These parameters may play a role in development of DNA damage in childhood patients with acute lymphoblastic leukemia (ALL).The ${\Delta}S^*$ and ${\Delta}G^*$ values were negative, these refer that the reaction of ES formation is spontaneous, but needs energy in a so-called endergonic reaction. Also the negative ${\Delta}S^*$ value of ceruloplasmin oxidase indicates that the complex [$ES^*$] is further modulated through increasing structure arrangement.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8623-8629
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• 2014

Background: As an important component of the NDC80 kinetochore complex, NUF2 is essential for kinetochore-microtubule attachment and chromosome segregation. Previous studies also suggested its involvement in development of various kinds of human cancers, however, its expression and functions in human hepatocellular carcinoma (HCC) are still unclear. Materials and Methods: In the present study, we aimed to test the hypothesis that NUF2 is aberrant in human HCCs and associated with cell growth. Results: Our results showed significantly elevated expression of NUF2 in human HCC tissues compared to adjacent normal tissues, and high expression of NUF2 in HCC cell lines. Using lentivirus-mediated silencing of NUF2 in HepG2 human HCC cells, we found that NUF2 depletion markedly suppressed proliferation and colony formation capacity in vitro, and dramatically hampered tumor growth of xenografts in vivo. Moreover, NUF2 silencing could induce cell cycle arrest and trigger cell apoptosis. Additionally, altered levels of cell cycle and apoptosis related proteins including cyclin B1, Cdc25A, Cdc2, Bad and Bax were also observed. Conclusions: In conclusion, these results demonstrate that NUF2 plays a critical role in the regulation of HCC cell proliferation and apoptosis, indicating that NUF2 may serve as a potential molecular target for therapeutic approaches.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.6
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• pp.123-138
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• 2017

This study aims to identify the characteristic variables of businesses that would impact the choice of their type in the 6th industry and analyze how they work. To this end, this study analyzed data of 752 businesses certified as belonging to the 6th industry in 2015 through the classification and regression tree (CART) algorithm in decision tree analysis. The results of analysis showed that the type of agricultural product processing affected shaping the type of the 6th industry at the early stage of growth while the type of agricultural product processing, the type of service, region and sales volumes at the stage of growth and service strategy and the type of agricultural product processing at the stage of maturity. These findings empirically identified key business factors that could support businesses in the 6th industry at each stage of growth and presented a direction forward for support of the 6th industry.