• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.320-325
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• 2016

In this paper, we propose an AlGaN/GaN-based extended-gate metal-insulator-semiconductor high electron mobility transistor (MISHEMT)-type biosensor for detecting streptavidin-biotin complexes. We measure the drain current of the fabricated sensor, which varies depending on the antibody-antigen reaction of streptavidin with biotin molecules. To confirm the immobilization of biotin polyethylene glycol (PEG) thiol, we analyze the Au surface of a GaN sample using X-ray photoelectron spectroscopy (XPS). The proposed biosensor shows higher sensitivity than Si-based extended-gate metal oxide semiconductor field effect transistor (MOSFET)-type biosensor. In addition, the proposed AlGaN/GaN-based extended-gate MISHEMT-type biosensor exhibits better long-term stability, compared to the conventional AlGaN/GaN-based MISHEMT-type biosensor.

• Journal of Sensor Science and Technology
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• v.23 no.2
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• pp.87-93
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• 2014

In this paper, we propose a block-based low-power complementary metal oxide semiconductor (CMOS) image sensor (CIS) with a simple pixel structure for power efficiency. This method, which uses an additional computation circuit, makes it possible to reduce the power consumption of the pixel array. In addition, the computation circuit for a block-based CIS is very flexible for various types of pixel structures. The proposed CIS was designed and fabricated using a standard CMOS 0.18 ${\mu}m$ process, and the performance of the fabricated chip was evaluated. From a resultant image, the proposed block-based CIS can calculate a differing contrast in the block and control the operating voltage of the unit blocks. Finally, we confirmed that the power consumption in the proposed CIS with a simple pixel structure can be reduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.1080-1099
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• 2019

A better tradeoff between robustness and invisibility will be realized by using the just noticeable (JND) model into the quantization-based watermarking scheme. The JND model is usually used to describe the perception characteristics of human visual systems (HVS). According to the research of cognitive science, HVS can adaptively extract the structure features of an image. However, the existing JND models in the watermarking scheme do not consider the structure features. Therefore, a novel JND model is proposed, which includes three aspects: contrast sensitivity function, luminance adaptation, and contrast masking (CM). In this model, the CM effect is modeled by analyzing the direction features and texture complexity, which meets the human visual perception characteristics and matches well with the spread transform dither modulation (STDM) watermarking framework by employing a new method to measure edge intensity. Compared with the other existing JND models, the proposed JND model based on structural regularity is more efficient and applicable in the STDM watermarking scheme. In terms of the experimental results, the proposed scheme performs better than the other watermarking scheme based on the existing JND models.

• 대한공업교육학회지
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• v.36 no.2
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• pp.47-64
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• 2011

The purpose of this study was to verify the effects of the technology-based STEAM education on attitude toward technology of middle school students. The following hypothesis was stated for the purpose of the study. There is no significant differences of attitude toward technology of middle school students before and after applied the technology-based STEAM education in sub-elements (1) interest in the technology, (2) technology's gender role, (3) technology's importance and influence, (4) accessibility to technology, (5) technology and school curriculum, (6) technology-related career, and (7) technology and creative activity. One-Group Pretest-Posttest Design was applied to 'After-school' activities of ${\bigcirc}{\bigcirc}$ middle school for this experimental research. The data were collected and interpreted statistically by paired samples t-test using SPSS(ver. 15) at the .05 level of significance. The results of the study were as follow: First, the technology-based STEAM education was effective in raising technological attitude of middle school students. Second, the technology-based STEAM education was effective in enhancing attitude of middle school students on interest in technology, technology's gender role, technology's importance and influence, technology and school curriculum, and creative activity. Third, the technology-based STEAM education was not effective in improving attitude on accessibility to technology and aspiration to technology-related occupation of middle school students.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.97-105
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• 2019

PURPOSE: This study examined the factors related to school-based activity performance in school-aged children with spastic cerebral palsy (CP). METHODS: The Gross Motor Function Systems (GMFCS), Manual Ability Classification System (MACS), Communication Function Classification System (CFCS) as functional classifications, and the physical activity performance of the School Function Assessment (SFA) were measured in 79 children with spastic CP to assess the student's performance of specific school-related functional activities. RESULTS: All the function classification systems were correlated significantly with the physical activity performance of the SFA ($r_s=-.47$ to -.80) (p<.05). The MACS (${\beta}=-.59$), GMFCS (${\beta}=-.23$), CFCS (${\beta}=-.21$), and age (${\beta}=-.15$) in order were predictors of the physical activity performance of the SFA (84.8%)(p<.05). CONCLUSION: These functional classification systems can be used to predict the school-based activity performance in school-aged children with CP. In addition, they can contribute to the selection of areas for intensive interventions to improve the school-based activity performance.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.277-280
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• 2005

With the proliferation of mobile terminals, use of the Internet in mobile environments is becoming more common. To support mobility in these terminals, Mobile IPv4 is proposed and represents the standard in IPv4 environments. Authentication should be mandatory, because mobile terminals can utilize Internet services in any foreign domain. Mobile IPv4 provides symmetric key based authentication using the default HMAC-MD5. However, symmetric key based authentication creates a key distribution problem. To solve this problem, public key based authentication mechanisms have been proposed. In this paper, the performance of each of these mechanisms is evaluated. The results present that, among these mechanisms, partial certificate based authentication has superior performance, and certificate based authentication has the worst performance. Although current public key based authentication mechanisms have lower performance than symmetric key based authentication, this paper presents the possibility that public key based authentication mechanisms may be used for future mobile terminal authentication.

• Asia pacific journal of information systems
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• v.30 no.4
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• pp.832-846
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• 2020

Service organizations increasingly adopt data-based intelligent engines called chatbots in support of the interaction between customers and the companies. Two different types of chatbots have been suggested and introduced by companies leading the adoption of this emerging technology: rule-based chatbots and natural language processing-based chatbots. While the differences between these two types of technologies look relatively clear, the organizational and practical impacts of the differences have not been systematically explored. This study performed an experiment to compare the use of the two different types of chatbots used in practice by two comparable organizations. These two types of actual chatbots were used by Korean on-line shopping malls with similar business models (mobile shopping), length of history, size and reputation. The comparison was made based on such dimensions as usability, searchability, reliability and attractiveness. Contraty to conventional expectation that the superiority in technology will produce superior usability, the results show mixed superiority. The discussion on the reasons is presented.

• Korean Institute of Interior Design Journal
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• v.13 no.4
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• pp.118-126
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• 2004

This study started from the premise that the future elementary school should be designed based on ecological approach in order to restore the emotionality of children. This study aimed at providing a guideline for designing the interior of elementary schools based on ecological approach. Through literature review, the characteristics of ecological architecture and the regulations for green buildings were explored. Also 7 elementary schools which were evaluated as good school design through renowned books representing the ecological characteristics were chosen and analyzed. The results revealed that the school design included natural lighting by roof lighting, natural ventilation, greening, and use of natural materials. This study suggested three categories as a the guideline for the interior space of eco-school design; energy efficiency, greening and sustainability, which included natural lighting, natural ventilation, heating and cooling, planting, materials and water recycling.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1273-1284
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• 2013

The purpose of this study is to develop vocational English textbooks for vocational high school, especially marine production high school. Vocational English is intended to increase English proficiency in the area of specific industry or jobs. Based on the review of the literature, the study established developed vocational English textbooks for marine production high school based on the modular system. The developing process includes analysis for marine production job, marine production high school and current English textbook for marine production. Based on the analysis, this study developed English contents which marine production students utilize in not only school but also workplace. Also, this study suggests future research directions for effective development and use of the textbooks in the vocational high schools.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4513-4532
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• 2014

Motivated by the Weber's Law, this paper proposes an efficient and robust shape descriptor based on the perceptual stimulus model, called Weber's Law Shape Descriptor (WLSD). It is based on the theory that human perception of a pattern depends not only on the change of stimulus intensity, but also on the original stimulus intensity. Invariant to scale and rotation is the intrinsic properties of WLSD. As a global shape descriptor, WLSD has far lower computation complexity while is as discriminative as state-of-art shape descriptors. Experimental results demonstrate the strong capability of the proposed method in handling shape retrieval.