• 대한본초학회지
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• 제20권2호
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• pp.61-68
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• 2005

Objectives : This is the study of the application as the ingredients of cosmetics through the examination of the function for physiological activity of Forsythia koreana Nakai. Methods : Forsythia koreana Nakai, which had been extracted, concentrated, and freeze drying with water and ethanol, have been used for the experiment. The effects on electronic donating ability, SOD-like activity, xanthine oxidase inhibition, whitening effect, nitric oxide inhibition have been investigated in the physiological activity measurement of function experiment. Results : According to the physiological activity measurement of function experiment, it had been found that the electron donating ability, at over 100ppm of water extract and ethanol extract showed relatively high donating ability by more than 80%, and as a result of measuring. In the xanthine oxidase inhibition test, 500ppm of water extract showed an effect of 18% and ethanol extract showed an effect of 31.5%. In the tyrosinase inhibition test, 5000ppm of water extract showed an effect of 60% and ethanol extract showed an effect of 85%. In the anti-inflammatory test, the water extract and ethanol extract inhibited the generation of nitric oxide. Conclusions : The results indicated that extract of Forsythia koreana Nakai can be used as a natural ingredients with biological function in cosmetics ingredients.

• 인터넷정보학회지
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• 제14권4호
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• pp.63-76
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• 2013

This short report introduces the general background why Brazil conference is being prepared and what topics would be undertaken and what goals are being taken into account. It overviews what differences from traditional telecommunication governance, internet governance has had in its historical development and how such differences had been formed from its technological differences and the regulatory policy shift from common carrier regulation to privatization. Moreover, the fact that open, voluntary, bottom-up, diverse stakeholder's participation had evolved throughout the historical development of the internet, had established the present multistakeholder governance model from technological standardization to addressing scheme policies. ICANN, which has governed internet addressing schemes since the earlier 2000s, had developed address policies including IANA function from Jon Postel and technical community's legacy management system into contract based formation between ICANN and gTLD, ccTLD registries. And it made dispute resolution policies responding to trademark disputes and resolved gTLD monopoly issue by introducing new TLD generation and the separation of registry and registar. However, there had been challenges on the legitimacy of ICANN due to its dependency on the Federal Government of the U.S. particularly in its oversight role over ICANN and IANA contract. WSIS raised up internet governance issues including addressing governance, and set up IGF as a discussion platform for multistakeholders to discuss and share all views on other internet related public policies. IGF's loose and non-binding discussion once frustrated governments and other stakeholders, but more focused discussion and visible outcomes have consolidated its unique role for internet governance discourses. Particularly, IGF addressed many emerging internet related issues like cybersecurity, privacy, net neuratlity, development related issues. WTPF of 2013, after WCIT debate on whether traditional telecommunication regulation could be applied to internet infrastructure, suggested other governance issues such as the transition to ipv6, IXP coordination etc. How to make sure the legitimacy of internet addressing governance and how and where other internet related public policies could be undertaken are fundamental tasks for internet governance. Brazil conference, which has been motivated by the breakdown of trust in internet governance from NSA mass surveillance revealed by Snowden, faces these questions and try to make consensus on principles, institutions and roadmap for internet governance in multistakeholder participation way.

• 한국환경교육학회지:환경교육
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• 제11권2호
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• pp.238-251
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• 1998

Environmental education, which has been thought as the most fundamental solution to environmental problems, should be performed not only in school but also in home and society with a long-term plan. In line with this, environmental-friendly attitude in daily life should be achieved by the perception of the vital environmental principle-new understanding of relation between nature and human being. It is in the city park that children in urban area, who has little opportunity to contact nature, have rather easier access to nature and realize the principle. Despite such great potential, the city park in Korea has not played its pivotal role because of lack of both facilities and activities. In addition, existing studies on this issue are not satisfactory. Therefore, this study is aimed at analyzing and evaluating city parks' environmental education function, potential and problems according to their types, then offering practical reform measures and programs in order to make students better understand the parks as an everyday natural experience spot. These plans are not based on full-scale revision, instead focuses on optimizing potential of existing natural environment and parks. Additionally, activities to experience various nature are included in the study. The value of city park is not decided by the park itself, but by its relationship with visitors. Environmental education function of city park is not confined to building up facilities and providing programs. It also should be complemented and improved, reflecting visitors' opinions and evaluation of environmental education.

• Nuclear Engineering and Technology
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• 제56권8호
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• pp.3425-3434
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• 2024

The main features of the loading pattern optimization (LPO) problem, such as high-dimensionality, multi-modality, and non-linearity, make it difficult to achieve a truly optimal configuration. In recent years, metaheuristic methods have been successfully used to solve this problem. In this research, a discrete golden eagle optimization (DGEO) algorithm has been developed to solve the LPO problem in the first cycle of VVER-1000 reactor core. To evaluate the proposed algorithm, a linear multi-purpose fitness function has been used to improve the safety parameters of the reactor core by obtaining a flatter power distribution during the first cycle, and also to enhance the economic parameters by increasing the cycle length and reducing the cost of fuel recycling. For this purpose, a FORTRAN program has been written to map the DGEO algorithm for the LPO problem using the PMAX and PARCS core calculation code to compute the fitness function in each iteration. To speed up the calculations, parallel computing has been applied in the written program. The results demonstrated that the loading pattern, which is suggested by the DGEO algorithm, enhances all the safety and economic parameters in the fitness function. Thus, the DGEO algorithm is highly reliable for the LPO problems in the VVER 1000 reactor core.

• 한국지능시스템학회논문지
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• 제16권6호
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• pp.671-676
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• 2006

일반적으로 가상 스피커 구현을 위한 음상정위 방법으로 HRTF(Head Related Transfer Function) DB를 원음에 convolution하는 기법을 사용하게 된다. 그러나 비개인화된 HRTF는 가상 스피커 구현에 있어 사용자에 따라 상/하 또는 앞/뒤 방향에 대해서 혼돈을 가져올 수 있어 정위감을 저하시킬 수 있다. 본 논문에서는 상/하, 앞/뒤 정위감을 개선하기 위해 가상 스피커 주변의 HRTF를 그룹화하여 만들어진 새로운 HRTF를 사용한 가상 스피커에 대하여 연구한다. 효과적인 HRTF 그룹화를 위해 필요한 HRTF 개수, 위치 등을 실험을 통해 결정하며, 청감 평가를 수행한다. 생성된 HRTF를 사용한 가상 스피커의 성능 평가 결과, 상/하, 앞/뒤 정위감이 개선됨을 실험을 통해 확인하였다.

• 오토저널
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• 제3권1호
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• pp.61-68
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• 1981

There are three types in frequency response accelerometer; one is lightly damped piezp type, another is oil damping stainguage type and the third is electro induction type accelerometer within electromagnetic damping. The usable frequency range of lightly damped accelerometers is limited to 0.2 of their mounted natural frequency for amplitude distortion of less than 5 percents. There have been situation where the measured motion contains unforeseen high - frequency components, which are regarded as such due to the accelerometer transfer function. There are several way to overcome amplitude distortion of the higher than anticipated frequency components; (I) to make use of the accelerometer with natural frequency three times and more as high as the measured frequency, (II) to establish data-analysis techniques which will account for the amplitude distortion, (III) to set up a notch filter circuit which has a transfer function that is the reciprocal of the accelerometer transfer function, and so on. This paper makes a report of the method as to(III), i. e., set up a few notch filter circuits, it is discussed what happens when the transfer functions, are in discord as to natural frequency of the filter and accelerometer damping vs. filter damping. And especially as for the cantilever strain gauge type accelerometer made by oneself with ease, it was compared and discussed between the ideological value and the experimental value of actual designed circuit in case of the mismatching of the transfer functions, and it was considered whether to be practicable or not, the result of which was as following; the useful frequency range of the accelerometer can be extended to near resonance if (a) the accelerometer mounted natural frequency and the filter center frequency are matched within .+-. 2 percent and (b) the damping ratios are matched within two factors. Therefore, we obtained the good result in improvement for extending frequency response characteristics of accelerometer.

• 한국컴퓨터정보학회논문지
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• 제26권4호
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• pp.133-142
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• 2021

본 연구의 목적은 여성노인을 대상으로 모던댄스, 아쿠아로빅, 복합운동 프로그램을 실시한 후 신체조성과 신체기능체력에 대한 변화 비교하여 여성노인에게 가장 적합한 운동이 무엇인지를 살펴보고자 실시되었다. 연구의 대상자는 J도에 거주하는 노인여성 47명을 대상으로 MDG(n=13) AEG(n=11), CEG(n=11), CG(n=12)을 무작위로 집단을 모집하여 12주간 주3회 1시간씩 운동을 실시하였다. 이 연구의 결과 통제그룹에 비해 grip strength, chair stand, arm curl, 2 minute step, 244cm up and go에서 유의한 차이를 보였으며, Back scratch는 MDG와 CEG에서만 운동 후 유의하게 감소하였으나 Chair sit and reach에서는 변화가 보이지 않았다. 본 연구결과 운동그룹 중 모던댄스(MDG)가 운동 후 가장 많은 신체기능체력이 향상된 것으로 나타났으며, 노인들에게 유연성과 관절의 가동성을 증진 시킬 수 있는 추가적인 운동프로그램이 필요하다. 또한 자신의 흥미에 맞는 운동을 자발적으로 참여하여 지속성 있게 하는 것이 중요할 것으로 생각된다.

• Environmental Engineering Research
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• 제10권4호
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• pp.191-198
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• 2005

A novel technology for the removal of nitrogen from wastewater, an autotrophic denitrification process with sulfur particles, has been developed. A respirometer was employed to monitor the nitrogen gas produced in the reactor, while 4',6-diamidino-2-phenylindole staining was employed to investigate the biomass distribution in terms of cell number according to the reactor height. From the respirometric monitoring, the denitrification reaction was defined as a first order reaction. The reactor was divided into 7 sections and biomass was analyzed in each section where cell number was ranged from $4.8\;{\times}\;10^6\;to\;8.7\;{\times}\;10^7$ cells/g dry weight of sulfur. Cells placed mostly in the lower layer ( < 10 cm of height). A function for biomass distribution was obtained with non-linear regression. Then a mathematical model has been developed by combining a plug-flow model with the biomass distribution function. The model could make a vertical profile of the up-flow packed-bed reactor resulting in a reasonable comparison with measured nitrate concentration with 5% of error range.

• 한국학교수학회논문집
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• 제17권3호
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• pp.359-384
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• 2014

본 연구는 고등학교 수학영재를 대상으로 한 GeoGebra 기반 수학영재 교수 학습 자료를 개발하여 수업에 적용해보고, 이 과정에서 나타나는 수학영재들의 인지적 특성을 알아보는데 있다. 실험 수업에 적용하기 위해 개발한 GeoGebra를 활용한 수학영재 교수 학습 자료는 기본도형의 작도, 슬라이더 도구를 이용한 애니메이션 만들기(함수의 그래프, 도형의 자취, 정적분, 고정점의 탐구, 매개변수 곡선 그리기 등), 이차곡선 탐구 등이며, 14차시 분량의 주제 탐구형으로 구성되었다. 그리고 개발한 자료를 적용하여 B과학고등학교 수학 동아리반 학생 14명을 연구 대상으로 약 4주간 동안 GeoGebra를 활용한 수업을 진행한 결과, 수업에서 수학영재들은 다양한 창의적 사고, 직관과 통찰, 논리적 사고, 수학적 추론 능력, 사고의 유연성 등의 인지적 특성을 나타냈다.

• 대한기계학회논문집A
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• 제21권5호
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• pp.819-827
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• 1997

In this paper, a new modeling of a fine actuator for an optical pick-up has been proposed and multiobjective optimization of the actuator has been performed. The fine actuator is constituted of the bobbin which is supported by wire suspension, the coils which wind around the bobbin, and the magnets which cause the magnetic flux. If current flows in the coils, magnetic force is so produced as to be balanced with spring force of wire, so the bobbin is pisitioned. In this model the transfer function from input voltage to output displacementof bobbin has been obtained so that we can describe this integrated system with electromagnetic and mechanical parts. Wire suspension is regarded as a continuous Euler beam, damper as distributed viscous damping, and bobbin as a rigid body which can move up- and down- ward motion only. According to the model, the high frequency dynamic characteristics of the fine actuator can be known and the effect of damping can be investigated while the conventional second order model cannot. In multiobjective optimization, two objective functions have been chosen to maximize the fundamental frequency and the sensitivity with respect to the input voltage of the actuator so that Pareto's optimal solutions have been obtained using .epsilon.-constraint method. These objective functions will satisfy the trends which will enhance the access speed and reduce the tracking error in the optical pick-up technology of next generation. In the result of optimization, we obtain the designs of the optical pick-up fine actuator which has high speed, high sensitivity and low resonant peak. Furthermore, we offer the relation between two object functions so that the designer can make easy choice.