• Journal of the Korean Chemical Society
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• v.59 no.4
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• pp.320-335
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• 2015

The purpose of this study was to identify the concepts of elementary school teachers related to three states of matter from activities of classifying various materials in life. The subjects were 25 teachers majored in primary science education at a graduate college of education and 10 teachers of elementary school located in a metropolitan city. A questionnaire and observation related to classification activities, and interviews were carried out and analyzed them qualitatively and quantitatively. From the analysis, we found that most elementary school teachers understood the classification criteria of three states of matter through macroscopic viewpoints and experienced difficulties in determining the state of mixture materials. After discussion of the classification results, the teachers’ concept was changed. But, when performing classification activity on the basis of the newly created concepts, it has not reached its results agreed. The result of this study shows that process of concept of science has been agreed in the same way to all people is not easy. Therefore, the teacher education programs to make possible to improve the ability capable of classifying the states of the various matters and to understand the nature of classification is required. In addition, deep discussion on the classification of the mixture is also necessary.

• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.425-431
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• 2008

The future cargo transportation and traffic volume on container in Gwangyang port was forecasted by using univariate time series models in this research. And the container ship traffic was produced. The constructed models all were most adapted to Winters' additive models with a trend and seasonal change. The cargo transportation on container in Gwangyang port was estimated each about 2,756 thousand TEU and 4,470 thousand TEU in 2011 and 2015 by increasing each 7.4%, 16.2% compared with 2007. The volume per ship on container was estimated each about 675TEU and 801TEU in 2011 and 2015 by increasing each 30.3%, 54.6% compared with 2007. Also, traffic volume on container incoming in Gwangyang Port was prospected each about 4,078ships and 5,921ships in 2011 and 2015.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.9
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• pp.63-73
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• 2015

This work proposes a 2-channel time-interleaved (T-I) 10b 120MS/s pipeline SAR ADC minimizing offset mismatch between channels without any calibration scheme. The proposed ADC employs a 2-channel SAR and T-I topology based on a 2-step pipeline ADC with 4b and 7b in the first and second stage for high conversion rate and low power consumption. Analog circuits such as comparator and residue amplifier are shared between channels to minimize power consumption, chip area, and offset mismatch which limits the ADC linearity in the conventional T-I architecture, without any calibration scheme. The TSPC D flip-flop with a short propagation delay and a small number of transistors is used in the SAR logic instead of the conventional static D flip-flop to achieve high-speed SAR operation as well as low power consumption and chip area. Three separate reference voltage drivers for 4b SAR, 7b SAR circuits and a single residue amplifier prevent undesirable disturbance among the reference voltages due to each different switching operation and minimize gain mismatch between channels. High-frequency clocks with a controllable duty cycle are generated on chip to eliminate the need of external complicated high-frequency clocks for SAR operation. The prototype ADC in a 45nm CMOS technology demonstrates a measured DNL and INL within 0.69LSB and 0.77LSB, with a maximum SNDR and SFDR of 50.9dB and 59.7dB at 120MS/s, respectively. The proposed ADC occupies an active die area of 0.36mm2 and consumes 8.8mW at a 1.1V supply voltage.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.76-76
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• 2016

2015년은 국제사회 거버넌스 및 정책 패러다임에 있어 전환점(tipping point)을 맞는다. 2000년 국제사회가 인류의 빈곤 퇴치라는 삶에 가장 절대적인 개발목표로 2015년까지 달성해야 할 빈곤, 의료, 교육 등 사회 환경 현안에서 해결해야 할 단순명료한 목표를 제시하였다. 그리고 2015년 9월 UN 지속가능 세계정상 회의(World Summit on Sustainable Development, WSSD)에서는 지속가능개발목표(Sustainable Development Goals, SDGs)를 채택하여 2030년까지 전 세계가 경제성장, 기후 변화 등 경제적, 사회적, 환경적 측면을 통합적으로 고려하여 지속가능한 인간정주환경을 조성하자는데 합의를 마쳤다. 17개의 지속가능개발목표와 부속적으로 169개의 타겟이 설정되었으며, SDGs 안에서는 MDGs의 기조를 유지하면서, 인간의 권리 구현과 성평등, 여성과 어린이의 권리 신장 등을 포함하고 있으며, 기후변화와 예측이 불확실한 다양한 자연재난, 특히 물과 물 관련 재해가 빈곤 경감, 기후변화 대응, 인간정주의 모든 삶의 영역에 연계요소로 녹아 있다. 기후변화 적응과 물 안보, 특히 위기관리의 맥락이 내재되어 있는 2030년을 목표로 하는 국제사회의 Post-2015 개발의제에서 물 분야는 무엇보다 중요한 관심 분야로 부각이 되어 있다. 17개의 지속가능개발목표에서 SDG6을 "모두를 위한 물과 위생의 지속가능한 관리와 이용(Ensure availability and sustainable management of water and sanitation for all)"으로 하고 수자원관리 및 물과 위생 분야의 중요성을 전세계가 공감하고 함께 해결해 나가야 함을 강조하였다. 그러나 실질적으로는 물을 직접적으로 언급한 6번째 목표뿐만 아니라, 빈곤의 근절(SDG1), 기아근절과 지속가능한 농업의 증진(SDG2)을 비롯한 다양한 목표들에서 물 분야가 직접?간접적으로 연계 되어 있으며, 특히 기후변화의 영향으로 더욱 심각해진 물관련 재해로부터 리질리언스 확보 등, 지속가능개발목표의 전반적인 기조에서 물안보 확보를 읽을 수 있다. 물 분야에서 지속가능개발목표의 이행을 위한 노력은 국제사회의 물 문제 해결에 공동으로 대응하기 위한 글로벌 동반 성장 지원체계를 구축하기 위한 초석이 될 것이다.

• Korean Chemical Engineering Research
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• v.53 no.1
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• pp.127-130
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• 2015

In this study, the adsorption equilibria of acetic acid on activated carbon were investigated at the temperatures of 313.15 K and 323.15 K. The obtained adsorption data were then fitted by Langmuir, Bi-Langmuir, and Freundlich models, in which the relevant model parameters were determined by minimizing the sum of the squares of deviations between experimental data and calculated values. The comparison results revealed that Bi-Langmuir model could account for the adsorption equilibrium data of acetic acid with the highest accuracy among the three adsorption models considered.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.71-76
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• 2015

To resolve inefficient content delivery mechanism in conventional internet-based networks, Content-Centric Networks (CCN) has been proposed for wired and wireless networks. One of issues in wireless CCN-based networks is overhead to achieve reliability on content delivery because CCN uses end-to-end two-way handshake with Interest/content packets. In this paper, a novel protocol to reduce overhead and achieve reliability is proposed. The protocol allows Interest packet to request multiple data packets and multiple data packets to be sent in a row without a Interest packets. The protocol is evaluated through the simulations and the performance improvement is proved.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.9-14
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• 2015

In this paper, we analysis the electromagnetic scattering of an arbitrary shape dielectric cube subjected to plane wave incidence in three dimensions. MoM(Method of Moments)in which a surface of a body is divided with small triangular patches and equivalence principle are used to fuse the PMCHW(Poggio, Miller, Chang, Harrington, and Wu) Integral Equations with respect to equivalent currents on a dielectric body. Triangular patch and loop-patch basis functions that is robust in wide frequency ranges are used for MoM formulations. Proposed method is very useful to analysis the induced current of arbitrary dielectric bodies and numerical results for a dielectric cube are presented.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.804-812
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• 2015

The purpose of this study was to analyze the perception of a high school teacher on Admission Officer System. The subjects were limited to 324 high school teachers of Busan, Ulsan, and Gyeongsangnam-do regions. The major research question for the study was how are the perceptions of high school teachers about the Admission Officer System. The main results were as follows: first, high school teachers showed high understanding of the admissions overall. Second, high school teachers with counseling experience about applying to colleges considered the score of the College Scholastic Ability Test less important. Third, high school teachers have recognized that there is a distance between high school education activities and the Admission Officer System. Eliciting sympathy from the high school teachers for the Admission Officer System is a very important task. Negative perceptions of high school teachers on the Admission Officer System is still remained. The cooperation between leading universities and high schools would help the Admission Officer System work with its original purpose or goal.

• The Journal of the Convergence on Culture Technology
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• v.1 no.1
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• pp.27-36
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• 2015

The purpose of this research is to try to enrich human life by applying the convergence energy of humanities and science to modern poetry. "Communication and entertainment", as modern poetry with modernist aesthetics, must indulge people's lives, which is simply to live happy lives. Entertainment is especially crucial because it is a method through which people can lead humane and satisfactory lives. The prerequisites for achieving this are true liberty and happiness. If these two prerequisites derive from humanity's consciousness, "communication and entertainment" can be born from "convergence of information technology and modern poetry", as the author insisted.

• Journal of the Korean Geotechnical Society
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• v.31 no.4
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• pp.13-18
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• 2015

Considering dredged ground is consolidated more than one meter, Compression index prediction is very important. But, UD-sampling and consolidation test are impossible because of high moisture content and weak shear strength. This paper demonstrates the compression index relation, $C_{c(d)}=F(e_d,C_c)$, between in-situ and dredged clay using N. Keith Tovey's Omega point and soil physical properties. Good relationship is confirmed between proposed formula and measured primary consolidation result on dredged ground in The Republic of Korea.